Sample records for pseudoaneurysm formation secondary

  1. Pseudoaneurysm secondary to transvesical prostatectomy

    PubMed Central

    Dell’Atti, Lucio; Galeotti, Roberto

    2016-01-01

    Pseudoaneurysms associated with the internal pudendal artery is rare and may occur as a complication of prostatic surgery or or pelvic trauma. We present images of the first case in literature of an isolated pseudoaneurysm secondary to transvesical prostatic adenomectomy, which was successfully treated by transarterial coil embolization. This complication can be difficult to diagnose, manage, and cause significant postoperative bleeding. Management requires as a multidisciplinary approach. PMID:27127364

  2. Pulmonary Artery Pseudoaneurysm Secondary to Lung Inf lammation.

    PubMed

    Ishimoto, Shinichirou; Sakurai, Hiroyuki; Higure, Ryouta; Kawachi, Riken; Shimamura, Mie

    2018-01-15

    Pulmonary artery aneurysms (PAA) and pseudoaneurysms (PAP) are caused by infections, vasculitis, trauma, pulmonary hypertension, congenital heart disease, and connective tissue disease. Most cases of such aneurysm occur in the trunk or major branches of the pulmonary artery, while the peripheral type is less common. The treatment modalities are medical therapy, surgery, and percutaneous catheter embolization. The mortality rate associated with rupture is approximately 50%. We encountered a case of a 53-year-old man with a pulmonary artery pseudoaneurysm secondary to pneumonia and cavity formation during chemotherapy for acute myeloid leukemia (AML). In diagnosis, contrast-enhanced chest computed tomography (CT) scan and pulmonary angiography were very useful. He was treated with right middle and lower lobectomy. After 1-month follow-up, he could restart additional chemotherapy.

  3. Right Ventricular Pseudoaneurysm Following Endomyocardial Biopsy.

    PubMed

    Pita; Santos; Manteiga; Rodriguez; Beiras

    1996-03-01

    Ventricular perforation is an unusual complication after endomyocardial biopsy in heart transplanted patients. We report a case of asymptomatic right ventricular perforation and pseudoaneurysm formation, secondary to endomyocardial biopsy, diagnosed by angiography. The spontaneous obliteration of the pseudoaneurysm was observed.

  4. Pseudoaneurysm following laparoscopic cholecystectomy.

    PubMed

    Madanur, Mansoor Ahmed; Battula, Narendra; Sethi, Harsheet; Deshpande, Rahul; Heaton, Nigel; Rela, Mohamed

    2007-06-01

    Laparoscopic cholecystectomy (LC) is the operation of choice for removal of the gallbladder. Unrecognized bile duct injuries present with biliary peritonitis and systemic sepsis. Bile has been shown to cause damage to the vascular wall and therefore delay the healing of injured arteries leading to pseudoaneurysm formation. Failure to deal with bile leak and secondary infection may result in pseudoaneurysm formation. This study was to report the incidence and outcomes of pseudoaneurysm in patients with bile leak following LC referred to our hospital. A retrospective analysis of our prospectively maintained liver database using key words pseudoaneurysm, bile leak and bile duct injury following laparoscopic cholecystectomy from January 2000 to December 2005 was performed. A total of 86 cases were referred with bile duct injury and bile leak following LC and of these, 4 patients (4.5%) developed hepatic artery pseudoaneurysm (HAP) presenting with haemobilia in 3 and massive intra-abdominal bleed in 1. Selective visceral angiography confirmed pseudoaneurysm of the right hepatic artery in 2 cases, cystic artery stump in one and an intact but ectatic hepatic artery with surgical clips closely applied to the right hepatic artery at the origin of the cystic artery in the fourth case. Effective hemostasis was achieved in 3 patients with coil embolization and the fourth patient required emergency laparotomy for severe bleeding and hemodynamic instability due to a ruptured right hepatic artery. Of the 3 patients treated with coil embolization, 2 developed late strictures of the common hepatic duct (CHD) requiring hepatico-jejunostomy and one developed a stricture of left hepatic duct. All the 4 patients are alive at a median follow up of 17 months (range 1 to 65) with normal liver function tests. HAP is a rare and potentially life-threatening complication of LC. Biloma and subsequent infection are reported to be associated with pseudoaneurysm formation. Late duct stricture is

  5. Aortic Pseudoaneurysm Secondary to Mediastinitis due to Esophageal Perforation

    PubMed Central

    Zuluaga, Claudia Patricia; Aluja Jaramillo, Felipe; Velásquez Castaño, Sergio Andrés; Rivera Bernal, Aura Lucía; Granada, Julio Cesar; Carrillo Bayona, Jorge Alberto

    2016-01-01

    Esophageal perforation is a condition associated with high morbidity and mortality rates; it requires early diagnosis and treatment. The most common complication of esophageal rupture is mediastinitis. There are several case reports in the literature of mediastinitis secondary to esophageal perforation and development of aortic pseudoaneurysm as a complication. We report the case of a patient with an 8-day history of esophageal perforation due to foreign body (fishbone) with mediastinitis and aortic pseudoaneurysm. The diagnosis was made using Computed Tomography (CT) with intravenous and oral water-soluble contrast material. An esophagogastroduodenoscopy did not detect the perforation. PMID:26977330

  6. Relationship between pseudoaneurysm formation and biloma after successful transarterial embolization for severe hepatic injury: permanent embolization using stainless steel coils prevents pseudoaneurysm formation.

    PubMed

    Hagiwara, Akiyoshi; Tarui, Takehiko; Murata, Atsuo; Matsuda, Takeaki; Yamaguti, Yoshihiro; Shimazaki, Shuji

    2005-07-01

    The purpose of this study was to determine the association between bilomas and pseudoaneurysm complications after severe hepatic injury. Angiography was performed in patients with American Association for the Surgery of Trauma grade > or = III hepatic injury on contrast-enhanced computed tomographic scanning. When contrast extravasation was observed, transarterial embolization (TAE) was performed. After TAE, technetium-99m pyridoxyl-5-methyl-tryptophan cholescintigraphy was performed to detect the coexistence of bilomas. Follow-up angiography was performed when a biloma was detected. Eighty consecutive patients underwent angiography; after angiography, five patients died. The remaining 75 patients who underwent cholescintigraphy were included in this study. All 11 patients who had bilomas had angiographic evidence of contrast extravasation. The biloma frequency was higher in patients with grades IV and V injuries than in those with grade III injury (p = 0.024). Follow-up angiography revealed pseudoaneurysms in 7 of these 11 patients. All six patients in whom only gelatin sponge pledget injection was used to embolize had pseudoaneurysms. Among them, two patients had computed tomographic evidence of massive intra-abdominal fluid collection. In contrast, only one of five patients who received the combination of gelatin sponge pledget injection and stainless steel coils to permanently embolize injured arteries had a pseudoaneurysm. In this patient, the pseudoaneurysm was found in the peripheral part of the collateral vessels. All patients with pseudoaneurysms underwent repeat TAE and were discharged from the hospital uneventfully. In patients with high-grade hepatic injury and arterial bleeding who developed biloma, use of a gelatin sponge, an absorbable embolic material, is associated with a risk of pseudoaneurysm formation. Permanent arterial embolization using stainless steel coils is indicated to decrease this risk.

  7. Delayed Development of Multiple Pancreaticoduodenal Arcade Pseudoaneurysms after Abdominal Trauma.

    PubMed

    Prosper, Ashley; Saremi, Farhood

    2016-10-01

    This case report demonstrates development and progressive enlargement of multiple pancreaticoduodenal arcade pseudoaneurysms using computed tomography angiographies over a period of 5 weeks after abdominal trauma. The mechanism of pseudoaneurysm formation, as shown by serial imaging, attributed to preexisting celiac axis stenosis by the median arcuate ligament, posttraumatic celiac artery dissection, and secondary occlusion of proper hepatic artery resulting in elevation of pressure and flow in the pancreaticoduodenal arcade and rupture of small arterial branches. Successful pseudoaneurysm occlusion was achieved through arterial embolization. Published by Elsevier Inc.

  8. Mycotic Pseudoaneurysm of Internal Carotid Artery Secondary to Lemierre's Syndrome, How to Do It.

    PubMed

    Benedetto, Filippo; Barillà, David; Pipitò, Narayana; Derone, Graziana; Cutrupi, Andrea; Barillà, Chiara

    2017-10-01

    We report the case of a patient with internal carotid artery (ICA) mycotic pseudoaneurysm secondary to Lemierre's syndrome, urgently treated. A 75-year-old man presented to E.R. with a left swelling lesion of the neck and complaining left visions lost since that morning, fever, hypotension, and dyspnea. Since 15 days before developing symptoms, he had sore throat and odynophagia treated with a broad coverage of antibiotic therapy for presumed streptococcal pharyngitis. Preoperative computed tomography angiography images revealed a circular lesion, involving the common carotid artery, carotid bulb, and the proximal part of the internal and external carotid arteries. A pseudoaneurysm of the ICA was detected, and the jugular vein was compressed. A Cormier carotid vein graft bypass was performed. Lemierre's syndrome is a rare syndrome, but it is rarer the carotid artery pseudoaneurysm secondary to Lemierre's syndrome. Surgical treatment is safe and durable in patients with severe infection involving the neck. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Clinics in diagnostic imaging (178). Wünderlich syndrome and pseudoaneurysm.

    PubMed

    Chung, Raymond; Chawla, Ashish; Peh, Wilfred Cg

    2017-06-01

    Wünderlich syndrome is a rare entity characterised by spontaneous retroperitoneal haemorrhage with renal origin. We present a case of Wünderlich syndrome secondary to clotting dyscrasia in a 64-year-old woman. The patient experienced a second Wünderlich haemorrhagic event with metachronous pseudoaneurysm formation, which was likely secondary to the large subcapsular haematoma stripping the renal capsule and tearing the cortical arteries. Selective pseudoaneurysm embolisations were successfully performed on both occasions. This clinical entity, its imaging differential diagnoses and management are discussed. Copyright: © Singapore Medical Association.

  10. Geniculate arterial pseudoaneurysm formation following trauma and elective orthopaedic surgery to the knee: 2 case reports and a review of the literature

    PubMed Central

    Shaw, A; Stephen, AB; Lund, JN; Bungay, P; DeNunzio, M

    2009-01-01

    Arterial pseudoaneurysm formation of the genicular vessels following orthopaedic surgery to the knee is an extremely rare occurrence. Here we report the successful management of two cases as a complication of total knee arthroplasty and a tibial interlocking nail, utilising coil embolisation by interventional radiological techniques and negating the need for further surgery. To our knowledge this is one of the few reported cases of pseudoaneurysms of the descending genicular artery secondary to drain placement and only the second following tibial interlocking nail placement. PMID:22470647

  11. Diagnosis of gynecological pseudoaneurysms and embolization with cyanoacrylate.

    PubMed

    Fernández Bermúdez, M J; Fernández Martínez, A M; Domitrovic, L A; Balboa Arregui, Ó

    Pseudoaneurysms of the uterine artery are an uncommon cause of severe gynecological bleeding secondary to surgical manipulation of the pelvis or to instrumental delivery. The different imaging techniques are of vital importance in the diagnosis. Angiography is the technique used for confirmation and also for treatment in many cases. Endovascular treatment by embolizing the pseudoaneurysm has become established as the treatment of choice, making it possible to avoid hysterectomy in women of childbearing age. This article presents two cases of gynecological bleeding due to pseudoaneurysms (one secondary to surgery and one secondary to childbirth) that were embolized in a novel way using cyanoacrylate. Copyright © 2016 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

  12. [Pancreatic tail pseudoaneurysm: percutaneous treatment by thrombin injection].

    PubMed

    Pacheco Jiménez, M; Moreno Sánchez, T; Moreno Rodríguez, F; Guillén Rico, M

    2014-01-01

    Visceral artery pseudoaneurysms secondary to acute and/or chronic pancreatitis are a relatively common and potentially serious complication. Endovascular techniques are the most currently accepted techniques, given the higher morbidity-mortality of surgery. The thrombosis of the pseudoaneurysm using an ultrasound-guided percutaneous thrombin injection is emerging as a useful option in those cases in which endovascular embolisation is not possible. We present the case of a patient with a pseudoaneurysm of the transverse pancreatic artery secondary to chronic pancreatitis, and successfully treated by administering percutaneous thrombin. Copyright © 2011 SERAM. Published by Elsevier Espana. All rights reserved.

  13. Uncommon incidental pseudoaneurysm. Diagnostic and management challenges.

    PubMed

    Hadidy, Azmy M; Samara, Osama A; Takrouri, Heba S; Al-Ryalat, Nosaiba T; Al-Smady, Moaath M; Ryalat, Soukaina T; Abu-Khalaf, Mahmoad M

    2009-08-01

    To analyze patients with uncommon incidental pseudoaneurysms, secondary to non-catheterization causes, and to discuss the peculiar clinical spectrum, and focus on some aspects of difference from post-catheterization pseudoaneurysms. Eleven patients, 8 males and 3 females, were studied retrospectively in Jordan University Hospital, Amman, Jordan, between 2002-2008. Radiological studies performed included duplex sonography (DS), computed tomography (CT), conventional angiography, magnetic resonance imaging (MRI), and magnetic resonance angiography (MRA). Pseudoaneurysms were most commonly encountered in young males (63.6%), especially in the lower limb vessels (36%). Clinical findings were suggestive of pseudoaneurysms in 27% of our cases. Four out of the 8 DS scans showed the neck of pseudoaneurysms, and the to and fro waveform, the strongest indicators for pseudoaneurysms. Both CT with intravenous contrast and angiography failed to establish the diagnosis in one out of 5 cases. The MRI with MRA showed the pseudoaneurysms in 2 patients that underwent the scan. Incidental pseudoaneurysms are considered following iatrogenic procedures, penetrating, or blunt traumas with variable delay time. Young healthy males are at increased risks, as opposed to elderly females with calcified vessels in post-catheterization cases. Duplex sonography is less sensitive in incidental than post-catheterization pseudoaneurysms. The CT scan with intravenous contrast has high accuracy in establishing the diagnosis in small, or medium sized pseudoaneurysms. The MRI and MRA are accurate valuable studies and comparable to conventional angiography.

  14. Severe hydronephrosis secondary to uterine artery pseudoaneurysm in the early second trimester of pregnancy: A case report.

    PubMed

    Amano, Tsukuru; Tokoro, Shinsuke; Tsuji, Shunichiro; Inoue, Takashi; Kimura, Fuminori; Murakami, Takashi

    2017-09-25

    Uterine artery pseudoaneurysm (UAP) normally presents genital bleeding in the puerperal period, and severe hydronephrosis rarely presents during pregnancy. We report a rare case of severe ureteral obstruction accompanied by uterine artery pseudoaneurysm in the early second trimester of pregnancy, which was successfully treated by surgical intervention. A 42-year-old nulligravid woman who had undergone myomectomy 3 years earlier was referred to our hospital for acute left abdominal pain at the 17th week of gestation. Ultrasonography showed severe left hydronephrosis and a 6-cm mass in the parauterine space. Color Doppler ultrasonography revealed a spinning turbulent flow pattern inside the mass lesion. Contrast-enhanced computed tomography revealed the left uterine artery feeding blood flow to the mass and left ureteral obstruction by the mass. These results indicated left hydronephrosis secondary to left uterine artery pseudoaneurysm. To resolve the problem, laparotomy was performed. As uterine artery isolation was impossible, ligation of the left internal iliac artery and releasing of the ureteral obstruction were carried out. The hydronephrosis and abdominal pain promptly resolved after the surgery. Thereafter, fetal development proceeded normally in the remaining months of the pregnancy. A healthy baby was delivered through cesarean section at 36 weeks gestational age. At the cesarean section, the left lower uterine segment where the UAP had been present was not visible because of the firm adhesion in around it. Uterine artery pseudoaneurysm can cause hydronephrosis in the early second trimester of pregnancy. Ligation of the unilateral internal iliac artery is a safe and effective intervention to block the blood flow to the uterine artery pseudoaneurysm during pregnancy, when uterine artery ligation seems not possible. In the pregnancy after previous surgical procedures to the uterus, uterine artery pseudoaneurysm should be considered in the differential

  15. Endovascular treatment of thoracic aortic pseudoaneurysm due to brucellosis: a rare case report.

    PubMed

    Wang, Shuai; Wang, Qi; Liu, Han; Sun, Siqiao; Sun, Xiwei; Zhang, Yang; Wang, Zhongying; Cheng, Zhihua

    2017-06-02

    Arterial damage is a known complication of brucellosis, but the occurrence of a thoracic aortic pseudoaneurysm secondary to brucellosis has not been previously reported. A 65-year-old Chinese man presented with a pseudoaneurysm in the descending segment of the thoracic aorta that caused symptoms of chest pain and intermittent fever. He was diagnosed with a thoracic aortic pseudoaneurysm secondary to brucellosis based on a positive brucella serology test (standard-tube agglutination test) and imaging examination (computed tomography angiography). Anti-brucellosis treatment and covered stent graft implantation were attempted to eliminate the brucellosis and pseudoaneurysm, respectively, and were ultimately successful, with no symptoms after 6 months of follow-up. Endovascular repair may be effective and safe for treating a thoracic aortic pseudoaneurysm resulting from brucellosis.

  16. [Hepatic artery pseudoaneurysm: report of two cases].

    PubMed

    Tun-Abraham, Mauro Enrique; Martínez-Ordaz, José Luis; Romero-Hernández, Teodoro

    2014-01-01

    Hepatic pseudoaneurysm is rare and potentially fatal. It occurs as a consequence of injury to the vascular wall, erosion diathermy through clips, biliary leakage and secondary infection. The main symptom is intra-abdominal bleeding. To communicate the case of two patients with hepatic pseudoaneurysm. Case 1: We present a 43 year-old male with a history of grade IV liver injury due to blunt abdominal trauma and managed surgically. Case 2: A 67 year-old man with bile duct injury after laparoscopic cholecystectomy. Both patients presented with biliary leakage, abdominal sepsis and late intra-abdominal bleeding. Tomographic studies showed the lesion. Superselective embolization was performed proximal and distal to the lesion with good results. During follow-up, none of them showed signs of recurrent bleeding. Hepatic artery pseudoaneurysm is rare and usually secondary to bile duct injury associated with vascular injury after cholecystectomy or liver trauma. Arteriography with embolization is the best diagnostic and therapeutic procedure. Surgery is indicated for hemodynamically unstable patients, embolization failure or rebleeding. Early diagnosis reduces morbidity and mortality of this complication.

  17. Characteristics of Pseudoaneurysms in Northern India; Risk Analysis, Clinical Profile, Surgical Management and Outcome.

    PubMed

    Lone, Hafeezulla; Ganaie, Farooq Ahmad; Lone, Ghulam Nabi; Dar, Abdul Majeed; Bhat, Mohammad Akbar; Singh, Shyam; Parra, Khursheed Ahmad

    2015-04-01

    To determine the risk factors, clinical characteristics, surgical management and outcome of pseudoaneurysm secondary to iatrogenic or traumatic vascular injury. This was a cross-sectional study being performed in department of cardiovascular and thoracic surgery skims soura during a 4-year period. We included all the patients referring to our center with primary diagnosis of pseudoaneurysm. The pseudoaneurysm was diagnosed with angiography and color Doppler sonography. The clinical and demographic characteristics were recorded and the risk factors were identified accordingly. Patients with small swelling (less than 5-cm) and without any complication were managed conservatively. They were followed for progression and development of complications in relation to swelling. Others underwent surgical repair and excision. The outcome of the patients was also recorded. Overall we included 20 patients with pseudoaneurysm. The mean age of the patients was 42.1±0.6 years. Among them there were 11 (55%) men and 9 (45%) women. Nine (45%) patients with end stage renal disease developed pseudoaneurysm after inadvertent femoral artery puncture for hemodialysis; two patients after interventional cardiology procedure; one after femoral embolectomy; one developed after fire arm splinter injury and one formed femoral artery related pseudoaneurysm after drainage of right inguinal abscess. The most common site of pseudoaneurysm was femoral artery followed by brachial artery. Overall surgical intervention was performed in 17 (85%) patients and 3 (15%) were managed conservatively. End stage renal disease is a major risk factor for pseudoaneurysm formation. Coagulopathy, either therapeutic or pathological is also an important risk factor. Patients with these risk factors need cannulation of venous structures for hemodialysis under ultrasound guide to prevent inadvertent arterial injury. Patients with end stage renal disease who sustain inadvertent arterial puncture during cannulation for

  18. A New Flow Control Technique Using Diluted Epinephrine in the N-butyl-2-cyanoacrylate Embolization of Visceral Artery Pseudoaneurysms Secondary to Chronic Pancreatitis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Morishita, Hiroyuki, E-mail: hmorif@koto.kpu-m.ac.jp; Yamagami, Takuji; Takeuchi, Yoshito

    2012-08-15

    Although n-butyl-2-cyanoacrylate (NBCA) has been used as an effective liquid embolization material, its indication for pseudoaneurysms has seemingly been limited because of the technical difficulties of using NBCA, such as reflux to the parent artery and causing significant infarction. Thus, considerable skill in using NBCA or a device to control blood flow during its polymerization is required to achieve embolization without severe complications. We report our new technique for controlling blood flow using diluted epinephrine in transcatheter arterial NBCA embolization of five pseudoaneurysms in four cases secondary to hemosuccus pancreaticus.

  19. Percutaneous coil embolization of massive pelvic pseudoaneurysm in an infant.

    PubMed

    Lillis, Anna P; Shaikh, Raja; Alomari, Ahmad I; Chaudry, Gulraiz

    2015-06-01

    Iatrogenic pseudoaneurysm formation is an uncommon but potentially serious complication of cardiac catheterization. This case report describes diagnosis and treatment of a large left external iliac artery pseudoaneurysm in a 3-month-old boy following cardiac catheterization and aortic balloon dilatation for aortic coarctation. A 4-cm pulsatile mass in the left hemipelvis was discovered on MRI performed 6 weeks later for possible tethered spinal cord. Sonography and angiography showed a large pseudoaneurysm of the left external iliac artery just distal to the iliac bifurcation with no flow in the external iliac artery distal to the pseudoaneurysm. Percutaneous US-guided thrombin injection was performed twice, with partial recanalization after each treatment. The residual portion of the pseudoaneurysm was then successfully embolized with percutaneous coils deployed under US and fluoroscopic guidance.

  20. Pseudoaneurysm after arthroscopic procedure in the knee☆

    PubMed Central

    Filho, Edmar Stieven; Isolani, Guilherme Rufini; Baracho, Filipe Ribas; de Oliveira Franco, Ana Paula Gebert; Ridder Bauer, Luiz Antônio; Namba, Mario

    2015-01-01

    The aim of this study was to review all cases of pseudoaneurysm in the literature, in predominantly arthroscopic procedures on the knee, and to report on a case of pseudoaneurysm that we treated. A bibliographic search was conducted for scientific articles published in Brazilian and foreign periodicals over the last 23 years. Forty-seven cases were found, in 40 articles. In addition to these 47 cases, there was the case that we treated, which was also included in the data. Among the operations that progressed with formation of a pseudoaneurysm, 60% were cases of meniscal injuries and 23%, anterior cruciate ligament injuries. In 46% of the cases, the artery affected with the popliteal, and in 21%, the inferomedial genicular artery. The commonest clinical symptom was pain (37%), followed by pulsating tumor (31%), edema of the calf (12%) and hemarthrosis (11%). The median time taken to make the diagnosis was 11 days, but it ranged from one day to 10 weeks after the procedure. Although rare, pseudoaneurysms are a risk that is inherent to arthroscopic surgery. All patients should be made aware of the vascular risks, even in small-scale procedures. PMID:26229905

  1. Pseudoaneurysm of the internal maxillary artery secondary to subcondylar fracture: case report and literature review.

    PubMed

    Moro, Alessandro; Todaro, Mattia; Pedicelli, Alessandro; Alexandre, Andrea; Pelo, Sandro; Doneddu, Piero; Gasparini, Giulio; Garagiola, Umberto; D'Amato, Giuseppe; Saponaro, Gianmarco

    2018-04-01

    Pseudoaneurysms are an uncommon complication of mandibular condylar-subcondylar fractures; however, if present, their recognition and management is mandatory to avoid life-threatening situations. The authors report a case of internal maxillary artery pseudoaneurysm rupture that occurred after an open reduction and internal fixation of a mandibular subcondylar fracture, along with a review of the literature.

  2. Long-term clinical and radiological outcome of endovascular embolization of pancreatitis-related pseudoaneurysms.

    PubMed

    Vander Mijnsbrugge, Ward; Laleman, Wim; Van Steenbergen, Werner; Heye, Sam; Verslype, Chris; Maleux, Geert

    2017-03-01

    Background Long-term outcome after embolization of pancreatitis-induced pseudoaneurysm is not yet determined. Purpose To assess the long-term efficacy and patients' overall survival after embolization of pancreatitis-induced pseudoaneurysm. Material and Methods Patients referred for endovascular treatment of a pancreatitis-induced pseudoaneurysm between January 1998 and January 2014 were analyzed. Embolization procedures were performed by transcatheter techniques using different types of embolic agents. Demographic, technical-radiological, and clinical data were collected. Results Thirty-four patients were identified with a pancreatitis-induced pseudoaneurysm; the underlying disease was acute (n = 13; 38%) or chronic (n = 21; 62%) pancreatitis; seven patients (20.6%) had active bleeding when embolized, while in the remaining 27 patients (79.4%) the pseudoaneurysm was not bleeding. In all 34 patients, successful endovascular exclusion of the pseudoaneurysm was obtained after the first attempt. Minor complications occurred in 11 patients (30%); no major complications were noted. A new pseudoaneurysm on a different vessel was identified during follow-up in three patients (9%). In another patient (3%), the excluded pseudoaneurysm reopened during follow-up. All four recurrences occurred within the first 5 months after embolization. Long-term follow-up (mean, 6.6 years; range, 4 months-16 years) revealed estimated survival rates of 94%, 89%, and 75% after 2, 5, and 10 years respectively, without pseudoaneurysm-related death. Conclusion Catheter-directed embolization of pancreatitis-induced pseudoaneurysms is relatively safe and effective. Recurrence or new pseudoaneurysm formation was low and occurred within the first 6 months after embolization. Overall survival is high, with no pseudoaneurysm-related deaths.

  3. Iatrogenic vertebral artery pseudoaneurysm due to central venous catheterization

    PubMed Central

    Vasquez, Jay

    2011-01-01

    Central venous lines have become an integral part of patient care, but they are not without complications. Vertebral artery pseudoaneurysm formation is one of the rarer complications of central line placement. Presented is a rare case of two pseudoaneurysms of the vertebral and subclavian artery after an attempted internal jugular vein catheterization. These were successfully treated with open surgical repair and bypass. Open surgical repair remains the gold standard of treatment. Endovascular repair of vertebral artery pseudoaneurysms has been described with promising outcomes, but long-term results are lacking. Ultimately, the best treatment of these iatrogenic injuries should start with prevention. Well-documented techniques to minimize mechanical complications, including inadvertent arterial puncture, should be practiced and taught in training programs to avoid the potentially devastating consequences. PMID:21566753

  4. Rare presentation of ruptured syphilitic aortic aneurysm with pseudoaneurysm.

    PubMed

    de Almeida Feitosa, Israel Nilton; Dantas Leite Figueiredo, Magda; de Sousa Belem, Lucia; Evelin Soares Filho, Antônio Wilon

    2015-11-01

    We report the interesting case of a rare form of presentation of rupture of the ascending aorta with formation of a pseudoaneurysm, diagnosed following the development of a large mass on the surface of the chest over a period of about eight months. Serological tests were positive for syphilis. Echocardiography and computed tomography angiography were essential to confirm the diagnosis and therapeutic management. Cardiovascular syphilis is a rare entity since the discovery of penicillin. Rupture of an aortic aneurysm with formation of a pseudoaneurysm is a potentially fatal complication. The postoperative period was uneventful and the patient was discharged from hospital within days of surgery. Copyright © 2015 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

  5. Retroperitoneal Pseudoaneurysm Mimicking Ureteral Calculus: Pitfalls in Diagnosis.

    PubMed

    Kalabin, Aleksandr; Mani, Vishnu R; Dinesh, Anant; Landa, Marina; Davis-Joseph, Brian

    2017-10-08

    Arterial aneurysms (AA) can be classified as true aneurysms, characterized by the persistence of all three layers of the arterial wall with progressive dilation and wall thinning; arterial pseudoaneurysms (APAs) are characterized by a tear in the vessel wall and a periarterial hematoma formation. They could occur due to a visceral, retroperitoneal, or peripheral origin. Most AA/APA are usually found incidentally, and it is imperative to be vigilant in order to diagnose and manage them due to their potentially life-threatening complications. We present a case of a 35-year-old woman presenting with right-sided abdominal pain mimicking renal colic with an initial misdiagnosis of ureteral calculus. Post-cystoscopy, a misdiagnosis was confirmed, and subsequently, the patient had a right retroperitoneal mass excision. The histopathology report concluded the calcified retroperitoneal mass to be pseudoaneurysm. Such pitfalls in diagnosis are essential to be shared with the larger medical community for increased vigilance and optimal management of pseudoaneurysms.

  6. Unusual angiographic changes in an internal carotid artery pseudoaneurysm after infection in the deep neck space.

    PubMed

    Hayashi, Yasuhiko; Shima, Hiroshi; Miyashita, Katsuyoshi; Kinoshita, Masashi; Nakada, Mitsutoshi; Kida, Shinya; Hamada, Jun-ichiro

    2008-05-01

    A 48-year-old man presented with a pseudoaneurysm at the cervical portion of the left internal carotid artery (ICA) secondary to infection in the deep neck space. Magnetic resonance (MR) imaging demonstrated enhancement of the wall of the ICA and a pseudoaneurysm, considered to be sequelae of infection spread. ICA occlusion occurred on the next day resulting in sudden onset of right hemiparesis and motor aphasia. The ICA pseudoaneurysm shrank gradually and his neurological deficits improved with conservative therapy. One month later, he presented with aneurysm regrowth. The common carotid artery was occluded with Guglielmi detachable coils to block arterial flow into the pseudoaneurysm. There were no neurological complications. Marked enhancement of the ICA wall on computed tomography and MR imaging may indicate the possibility of vascular complications such as rupture, pseudoaneurysm development, or ICA occlusion, and consequent neurological deficits. ICA occlusion caused by spread of infection in the deep neck space may cause accelerated coagulopathy due to ICA wall inflammation.

  7. Management of chronic pancreatitis complicated with a bleeding pseudoaneurysm.

    PubMed

    Chiang, Kun-Chun; Chen, Tsung-Hsing; Hsu, Jun-Te

    2014-11-21

    Chronic pancreatitis is an ongoing disease characterized by persistent inflammation of pancreatic tissues. With disease progression, patients with chronic pancreatitis may develop troublesome complications in addition to exocrine and endocrine pancreatic functional loss. Among them, a pseudoaneurysm, mainly induced by digestive enzyme erosion of vessels in proximity to the pancreas, is a rare and life-threatening complication if bleeding of the pseudoaneurysm occurs. At present, no prospective randomized trials have investigated the therapeutic strategy for this rare but critical situation. The role of arterial embolization, the timing of surgical intervention and even surgical procedures are still controversial. In this review, we suggest that dynamic abdominal computed tomography and angiography should be performed first to localize the bleeders and to evaluate the associated complications such as pseudocyst formation, followed by arterial embolization to stop the bleeding and to achieve early stabilization of the patient's condition. With advances and improvements in endoscopic devices and techniques, therapeutic endoscopy for pancreatic pseudocysts is technically feasible, safe and effective. Surgical intervention is recommended for a bleeding pseudoaneurysm in patients with chronic pancreatitis who are in an unstable condition, for those in whom arterial embolization of the bleeding pseudoaneurysm fails, and when endoscopic management of the pseudocyst is unsuccessful. If a bleeding pseudoaneurysm is located over the tail of the pancreas, resection is a preferential procedure, whereas if the lesion is situated over the head or body of the pancreas, relatively conservative surgical procedures are recommended.

  8. Retroperitoneal Pseudoaneurysm Mimicking Ureteral Calculus: Pitfalls in Diagnosis

    PubMed Central

    Kalabin, Aleksandr; Dinesh, Anant; Landa, Marina; Davis-Joseph, Brian

    2017-01-01

    Arterial aneurysms (AA) can be classified as true aneurysms, characterized by the persistence of all three layers of the arterial wall with progressive dilation and wall thinning; arterial pseudoaneurysms (APAs) are characterized by a tear in the vessel wall and a periarterial hematoma formation. They could occur due to a visceral, retroperitoneal, or peripheral origin. Most AA/APA are usually found incidentally, and it is imperative to be vigilant in order to diagnose and manage them due to their potentially life-threatening complications. We present a case of a 35-year-old woman presenting with right-sided abdominal pain mimicking renal colic with an initial misdiagnosis of ureteral calculus. Post-cystoscopy, a misdiagnosis was confirmed, and subsequently, the patient had a right retroperitoneal mass excision. The histopathology report concluded the calcified retroperitoneal mass to be pseudoaneurysm. Such pitfalls in diagnosis are essential to be shared with the larger medical community for increased vigilance and optimal management of pseudoaneurysms. PMID:29226048

  9. [Hepatic artery pseudoaneurysm following blunt abdominal injury].

    PubMed

    Kargl, S; Breitwieser, J; Gitter, R; Pumberger, W

    2012-12-01

    Posttraumatic hepatic artery pseudoaneurysms are a rare but life-threatening complication of blunt abdominal trauma with liver damage. We report the case of a child who developed a pseudoaneurysm of the right hepatic artery after a bicycle accident with central liver rupture. After an episode of hemodynamically relevant hemobilia due to delayed bleeding, the asymptomatic pseudoaneurysm was diagnosed coincidentally by ultrasound. Because of the progression in size angiographic coiling was performed and led to thrombotic occlusion of the pseudoaneurysm. After a symptom-free period of 1 month the child required surgery because of acute cholecystitis.

  10. Inferior gluteal artery pseudoaneurysm related to intramuscular injection

    PubMed Central

    Saad, Paulo Fernandes; Saad, Karen Ruggeri; Armstrong, Dinani Matoso Fialho de Oliveira; Soares, Bruno Leonardo de Freitas; de Almeida, Paulo Henrique Freitas; Razuk Filho, Álvaro

    2014-01-01

    INTRODUCTION Gluteal artery pseudoaneurysms are rare, yet the most common in cases involving the superior gluteal artery. Pseudoaneurysms of the inferior gluteal artery are uncommon and are often related to blunt or penetrating trauma, infections and fractures of the pelvis. PRESENTATION OF CASE The authors present a case of pseudoaneurysm of the inferior gluteal artery related to an iatrogenic injury due to intramuscular injection of medication, which was treated with selective embolization of the artery during angiography. DISCUSSION The most common manifestation of an inferior gluteal artery pseudoaneurysm is the presence of a painful mass in the buttock that may or may not be associated with neurological symptoms due to compression of the sciatic nerve. Ultrasound with color Doppler and computerized tomography with multi-detectors are useful non-invasive tools for diagnosis. However, both diagnosis and therapy are facilitated by catheter angiography. CONCLUSION This case cautions that although pseudoaneurysms are rare, pseudoaneurysms of the inferior gluteal artery require a high index of suspicion and careful physical examination by the physician in order to avoid misdiagnosis. It also illustrates the usefulness of a minimally invasive modality for treatment of these lesions. PMID:25506847

  11. Endovascular Repair of a Pseudoaneurysm of the Abdominal Aorta Secondary to Translumbar Aortography

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mir, Naheed; Nunzio, Mario De; Pollock, John G

    This report describes an incidental finding of a pseudoaneurysm of the abdominal aorta on a computed tomography (CT) renal angiogram during investigation of chronic renal failure in a 73-year-old man. The patient had undergone a translumbar aortogram 20 years previously. An increase in the size of the aneurysm by 7 mm over 6 months prompted treatment and the aneurysm underwent successful endovascular repair with a custom-made stent-graft.

  12. Endovascular management of iatrogenic native renal arterial pseudoaneurysms.

    PubMed

    Sildiroglu, Onur; Saad, Wael E; Hagspiel, Klaus D; Matsumoto, Alan H; Turba, Ulku Cenk

    2012-12-01

    Our purpose was to evaluate iatrogenic renal pseudoaneurysms, endovascular treatment, and outcomes. This retrospective study (2003-2011) reported the technical and clinical outcomes of endovascular therapy for renal pseudoaneurysms in eight patients (mean age, 46 (range 24-68) years). Renal parenchymal loss evaluation was based on digital subtraction angiography and computed tomography. We identified eight iatrogenic renal pseudoaneurysm patients with symptoms of hematuria, pain, and hematoma after renal biopsy (n = 3), surgery (n = 3), percutaneous nephrolithotomy (n = 1), and endoscopic shock-wave lithotripsy (n = 1). In six patients, the pseudoaneurysms were small-sized (<20 mm) and peripherally located and were treated solely with coil embolization (n = 5). In one patient, coil embolization was preceded by embolization with 500-700 micron embospheres to control active bleeding. The remaining two patients had large-sized (≥50 mm), centrally located renal pseudoaneurysms treated with thrombin ± coils. Technical success with immediate bleeding cessation was achieved in all patients. There were no procedure-related deaths or complications (mean follow-up, 23.5 (range, 1-67) months). Treatment of renal pseudoaneurysms using endovascular approach is a relatively safe and viable option regardless of location (central or peripheral) and size of the lesions with minimal renal parenchymal sacrifice.

  13. Left ventricular pseudoaneurysm - a challenging diagnosis.

    PubMed

    Faustino, Mariana; Ranchordás, Sara; Abecasis, João; Freitas, António; Ferreira, Moradas; Gil, Victor; Morais, Carlos; Neves, José Pedro

    2016-06-01

    Left ventricular pseudoaneurysm is a rare complication of acute myocardial infarction, associated with high mortality. However, it can present in a non-specific manner, complicating and delaying the diagnosis. The authors present the case of a 65-year-old patient, hypertensive, with no other known relevant medical history, who presented with chest pain, cough and left pleural effusion, initially attributed to a pulmonary process. However, these were in fact the result of a left ventricular pseudoaneurysm following silent acute myocardial infarction. The diagnosis was suspected on echocardiography and confirmed by cardiac magnetic resonance imaging, and the patient underwent successful surgical pseudoaneurysm repair. This case illustrates an atypical presentation of a left ventricular pseudoaneurysm, in which the manifestations resulted from pericardial and pleural extension of the inflammatory process associated with contained myocardial rupture. The case demonstrates the need for a high index of suspicion, and the value of imaging techniques to confirm it, in order to proceed with appropriate surgical treatment, and thus modify the course of the disease. Copyright © 2015 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

  14. Endovascular Repair of a Traumatic Axillary Pseudoaneurysm Following Anterior Shoulder Dislocation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Stahnke, Michaela; Duddy, Martin J.

    2006-04-15

    Pseudoaneurysms due to musculoskeletal trauma are rare and comprise less than 2% of all pseudoaneurysms. We report a case of axillary pseudoaneurysm following anterior dislocation of the shoulder. The patient was successfully treated by endovascular intervention.

  15. Ruptured superior gluteal artery pseudoaneurysm with hemorrhagic shock: Case report.

    PubMed

    Corbacioglu, Kerem Seref; Aksel, Gokhan; Yildiz, Altan

    2016-03-01

    Pseudoaneurysm of the superior gluteal artery (SGA) is very rare and the most common causes are blunt or penetrating pelvic traumas. Although pseudoaneurysm can be asymptomatic at the time of initial trauma, it can be symptomatic weeks, months, even years after initial trauma. We present a case of a ruptured superior gluteal artery pseudoaneurysm with hemorrhagic shock twenty days after a bomb injury in the Syria civil war. In addition, we review the anatomy of the SGA, clinical presentation and pitfalls of pseudoaneurysm, and imaging and treatment options.

  16. [Graft Pseudoaneurysm after Ascending to Abdominal Aorta Bypass for Atypical Coarctation Due to Aortitis Syndrome;Report of a Case].

    PubMed

    Yada, Masashi; Yamanaka, Kazuo; Miwa, Senri; Hirose, Keiichi; Sakaguchi, Hisashi; Yoshida, Yukiyo; Onga, Youhei; Tara, Yuichi

    2017-05-01

    We present a case of a 44-year-old woman, with pseudoaneurysm formation at the middle of the prosthetic graft, 60 mm in diameter. She had been diagnosed with atypical coarctation due to aortitis 27 years before, and had undergone a bypass operation with 14 mm-diameter Cooley double velour graft from the ascending aorta to the abdominal aorta. This time, endovascular aortic repair was performed to prevent rupture of the pseudoaneurysm. Though a knitted Dacron graft has a risk of psuedaneurysm formation long patency could be obtained when used in ascending aorta-abdominal aorta bypass.

  17. Spontaneous closure of post-intervention left anterior descending coronary pseudoaneurysm.

    PubMed

    Nunes, Rafael A B; Cade, Jamil R; Silva, Rafael C; Brito Júnior, Fábio S; Freitas, Humberto F G

    2014-06-01

    Coronary pseudoaneurysms are an unusual finding during coronary angiography and there are very little data on their prognosis in the literature. We report the case of a 62-year-old man admitted with an anterior myocardial infarction who developed a pseudoaneurysm in the mid left anterior descending artery some days after a type I coronary perforation during coronary angioplasty. Spontaneous closure of the pseudoaneurysm was observed during hospital follow-up. Spontaneous closure of coronary pseudoaneurysms may be more common in clinical practice than previously thought, but few cases have been reported. As the natural history of post-intervention coronary pseudoaneurysms has been little investigated, reports of their occurrence may help to clarify their evolution. Copyright © 2013 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

  18. Ultrasound-guided thrombin injection of genicular artery pseudoaneurysm.

    PubMed

    Rachakonda, Aditya; Qato, Khalil; Khaddash, Tamim; Carroccio, Alfio; Pamoukian, Vicken; Giangola, Gary

    2015-07-01

    Pseudoaneurysm is a rare complication after arthroscopic procedures involving the knee. A 38-year-old man presented 1 month after right-knee arthroscopy with a 2-cm pulsating mass on the medial side of the right knee. Duplex ultrasound evaluation revealed 2.5 × 2.1-cm pseudoaneurysm just distal to the patella with arterialized flow communicating with the inferior medial genicular artery. Ultrasound-guided thrombin injection was performed in an office setting, and the resolution of active flow within the pseudoaneurysm was confirmed with duplex ultrasonography. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Management of Iatrogenic Pseudoaneurysms in Patients Undergoing Coronary Artery Bypass Grafting.

    PubMed

    Stone, Patrick A; Thompson, Stephanie N; Hanson, Brent; Masinter, David

    2016-05-01

    A plethora of papers have been written regarding postcatheterization femoral pseudoaneurysms. However, literature is lacking on pseudoaneurysmal management in patients undergoing coronary artery bypass grafting (CABG). Thus, we examined if pseudoaneurysms with subsequent CABG can be managed with the same strategies as those not exposed to the intense anticoagulation accompanying CABGs. During a 14-year study period, we retrospectively examined femoral iatrogenic pseudoaneurysms (IPSAs) diagnosed postheart catheterization in patients having a subsequent CABG. Patient information was obtained from electronic medical records and included pseudoaneurysm characteristics, treatment, and resolution. Outcomes of interest included the occurrence of IPSA treatment failures and complications. In the 66 patients (mean age, 66 ± 11 years, 46% male) meeting inclusion criteria, mean dose of heparin received during the CABG procedure was 34 000 ± 23 000 units. The IPSA size distribution was the following: 17% of IPSAs measured <1 cm, 55% between 1 and 3 cm, and 21% measured >3 cm. Pseudoaneurysms were managed with compression, duplex-guided thrombin injection, and surgical repair (1%, 27%, and 26% of cases, respectively). Thrombin injection and surgical repair were 100% effective at treating pseudoaneurysms, with 1 patient experiencing a surgical site infection postsurgical repair. Observation-only management was employed in 30 (45%) patients. Nine of 30 patients with no intervention beyond observation had duplex documented resolution/thrombosis during follow-up. One patient initially managed by observation required readmission and surgical repair of an enlarging pseudoaneurysm (6 cm growth) following CABG. Management of pseudoaneurysms in patients prior to CABG should be similar to those patients not undergoing intense anticoagulation. In appropriate cases, small aneurysms can be safely observed, while thrombin injections are effective and safe as well. Thus, routine open

  20. Endovascular Management of Superior Mesenteric Artery Pseudoaneurysm and Fistula

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Narayanan, Govindarajan, E-mail: gnarayanan@med.miami.ed; Mohin, Geetika, E-mail: geetika77@yahoo.co; Barbery, Katuska, E-mail: kbarbery@med.miami.ed

    2008-11-15

    The uncommon presentation of an arterioportal fistula (APF) involving the superior mesenteric artery (SMA) associated with a pseudoaneurysm represents a therapeutic challenge. We present the case of a 24-year-old female admitted to the hospital after multiple gunshot wounds to the abdomen; the patient underwent multiple surgeries and, in the process, developed a SMA pseudoaneurysm and fistula. The vascular interventional radiology team was consulted for treatment of the pseudoaneurysm and fistula. A covered stent was inserted percutaneously to exclude the APF and the pseudoaneurysm in a single procedure. The patient returned to our service after 21 months for a follow-up CTmore » scan, which demonstrated the stent and the distal vasculature to be patent.« less

  1. A bulbar artery pseudoaneurysm following traumatic urethral catheterization.

    PubMed

    Bettez, Mathieu; Aubé, Melanie; Sherbiny, Mohamed El; Cabrera, Tatiana; Jednak, Roman

    2017-01-01

    Traumatic urethral catheterization may result in a number of serious complications. A rare occurrence is the development of a urethral pseudoaneurysm. We report the case of a 13-year-old male who required placement of a Foley catheter for an orthopedic surgical procedure. The Foley was misplaced in the bulbourethra, resulting in the development of a bulbar artery pseudoaneurysm. Profuse bleeding via the urethra was noted after removal of the catheter, and the patient experienced severe intermittent hematuria during the postoperative period. Cystoscopy revealed a pulsatile mass within the bulbourethra. Angiography confirmed a bulbar artery pseudoaneurysm, which was successfully embolized with resolution of bleeding.

  2. Reducing duplex examinations in patients with iatrogenic pseudoaneurysms.

    PubMed

    Stone, Patrick A; Aburahma, Ali F; Flaherty, Sarah K

    2006-06-01

    Ultrasound-guided thrombin injection has become the initial treatment of choice for femoral access-related pseudoaneurysms. Patients typically undergo serial duplex examinations to assess for spontaneous resolution of small iatrogenic pseudoaneurysms (IPSAs) (<2.5 cm), or may require repeated diagnostic, therapeutic, and follow-up studies for larger IPSAs (>2.5 cm). We evaluated the impact of a revised treatment algorithm that includes primary treatment of both small (<2.5 cm) and larger pseudoaneurysms (>2.5 cm), rather than observation of smaller ones, and attempts to establish a single duplex examination via a point-of-care treatment strategy. We reviewed 105 consecutive patients treated with ultrasound-guided thrombin injection from July 2001 through September 2004. Patient, IPSAs, characteristics, and treatment methods were examined. The number of duplex examinations per patient was evaluated over the treatment interval. Also, published cost data were used to compare primary treatment of small ISPAs vs observation with serial duplex examinations. Successful thrombosis occurred in 103 (98.1%) of 105 treated pseudoaneurysms. No minor or major complications occurred after thrombin injection in either small or large ISPAs, and both failures requiring operation were in the large aneurysm group. The recurrence rate for the series was 1.9% (2/105), and both recurrences were successfully treated with an additional thrombin injection. A single injection was successful in treating 43 (97.7%) of 44 small (<2.5 cm) IPSAs, and one required a second injection. Patients had an average of 3.3 duplex examinations in our first year of treatment experience, which declined to 1.5 by our third year with the institution of a point-of-care service model for all pseudoaneurysms. Based on this decreased use of duplex examination and an average treatment cohort of 35 IPSA patients per year our institution, we determined this results in a reduction of 35 hours of laboratory time and

  3. [Transhepatic percutaneous embolisation of a post-traumatic pseudoaneurysm of hepatic artery].

    PubMed

    Marcheix, B; Dambrin, C; Cron, C; Sledzianowski, J F; Aguirre, J; Suc, B; Cerene, A; Rousseau, H

    2004-12-01

    Pseudoaneurysm of the hepatic artery is a rare complication of blunt abdominal trauma. We report a case of post-traumatic pseudoaneurysm diagnosed several months after the initial traumatism in a 18-year-old man who presented recurrent abdominal pain. This pseudoaneurysm was successfully treated by association of both classical endovascular treatment and transhepatic percutaneous embolization.

  4. Minimally invasive therapy of pseudoaneurysms of the trunk: application of thrombin.

    PubMed

    Schellhammer, Frank; Steinhaus, Daniele; Cohnen, Mathias; Hoppe, Jonas; Mödder, Ulrich; Fürst, Günter

    2008-01-01

    Thrombin injection has been proven to be successful in postcatheterization pseudoaneurysms. However, there are only a few reports on the treatment of pseudoaneurysms of the trunk. We report our first experiences using a percutaneous as well as an endovascular access. Eight iatrogenic pseudoaneurysms of the trunk (aorta, n = 4; pulmonary artery, n = 1; gastroduodenal artery, n = 1; left gastric artery, n = 1, renal artery, n = 1) were treated either percutaneously using CT guidance (n = 3) or via an endovascular access (n = 5). Noninvasive control angiograms were performed at day 1 and weeks 1 and 3 by either CT or MR angiography. The total volume of the pseudoaneurysms was 31.2 +/- 23.1 ml on average, with a mean volume of the perfused aneurysmal lumen of 12.9 +/- 7.2 ml. The maximum diameter was 4.1 +/- 1.39 cm on average. In each case, the aneurysmal neck was not wider than 2 mm. One pseudoaneurysm occluded spontaneously following selective catheterization. The remaining pseudoaneurysms were successfully treated by injection of 765 +/- 438.1 IU thrombin. In one individual, a nontarget embolization occurred, as well as an intervention-associated rupture of a pseudoaneurysm. High-grade stenoses of the donor artery were found in a different case. Only once was the endoluminal access converted to a percutaneous one. Thrombin injection might be a future first-line treatment of vascular lesions such as pseudoaneurysms of the trunk. In our experience both percutanous and endoluminal access are technically feasible and safe. However, further experiences are mandatory, especially concerning the question of dosage and long-term results.

  5. Left ventricular lipoma with pseudoaneurysm-like appearance.

    PubMed

    Kawarai, Shun-ichi; Yaginuma, Gen-ya; Abe, Kazuo; Hamasaki, Azumi; Ishikawa, Kazunori; Tanaka, Daizo

    2010-06-01

    We describe an extremely rare cardiac lipoma, with electrocardiographic changes in ST segments and T waves, suggesting ischemic heart disease. The abnormal electrocardiogram was identified during a routine physical examination of an asymptomatic 57-year-old man. Coronary angiography showed no stenotic or occlusive lesions in the coronary arteries except that the left anterior descending artery followed a winding course in the apical region. Left ventriculography revealed a pseudoaneurysm-like mass around the apical portion. Computed tomography and magnetic resonance imaging revealed a cardiac lipoma that communicated with the left ventricle and resembled a pseudoaneurysm. After complete resection of the lipoma and left ventricle patch plasty, the postoperative course was uneventful. Histologically, the tumor was an intramyocardiac lipoma with no evidence of malignancy. To our knowledge, we are the first to describe an intramyocardiac lipoma resembling a left ventricle pseudoaneurysm.

  6. Thrombin Injection Failure with Subsequent Successful Stent-Graft Placement for the Treatment of an Extracranial Internal Carotid Pseudoaneurysm in a 5-Year-Old Child

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Garcia-Monaco, R. D.; Kohan, A. A., E-mail: andreskohan1@gmail.com; Martinez-Corvalan, M. P.

    Internal carotid artery pseudoaneurysm is a rare life-threatening condition that may develop in different clinical situations. We report the case of an extracranial internal carotid artery pseudoaneurysm secondary to a throat infection in a pediatric patient that was initially treated with percutaneous thrombin injection under ultrasound guidance. However, recanalization occurred at 48 h, and definitive treatment was then performed by endovascular stent-graft placement. We briefly review the clinical characteristics of this uncommon clinical condition as well as the treatment options.

  7. Surgical exclusion of postsurgical pseudoaneurysm of the ascending aorta

    PubMed Central

    Barik, Ramachandra; Patnaik, Amar Narayana; Kumar, Ravintula Venkata; Mohapatra, Rudra Prasad; Medep, Vikas; Nemani, Lalita

    2014-01-01

    Pseudoaneurysm of ascending aorta after cardiac surgery is rare in children. We report a case of successful surgical exclusion of ascending aortic pseudoaneurysm in a 15-year-old boy. The neck of the aneurysm was in close proximity to the right coronary artery (RCA). PMID:24987261

  8. Iatrogenic aortic pseudoaneurysm: a forgotten complication.

    PubMed

    Almeida, Samuel; Bico, Pedro; Almeida, António R; Laranjeira Santos, Álvaro; Banazol, Nuno; Fragata, José; Rabaçal, Carlos

    2014-02-01

    Pseudoaneurysms of the ascending aorta are a rare complication of cardiac surgery. However, the poor prognosis associated with this condition if untreated makes early diagnosis and treatment important. We present the case of a 66-year-old woman who had undergone mitral valvuloplasty 12 days previously, who was admitted with a diagnosis of new-onset atrial fibrillation. The transthoracic echocardiogram showed a clot in the right atrium and anticoagulation was initiated, followed by antibiotic therapy. After further investigation, the patient was diagnosed with a pseudoaneurysm of the ascending aorta and underwent surgical repair, followed by six weeks of antibiotic therapy. She was readmitted six months later for an abscess of the lower sternum and mediastinum. After a conservative approach with antibiotics and local drainage failed, recurrence of a large pseudoaneurysm compressing the superior vena cava was documented. A third operation was performed to debride the infected tissue and to place an aortic allograft. There were no postoperative complications. Copyright © 2012 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

  9. Heparin surface stent-graft for the treatment of a carotid pseudoaneurysm.

    PubMed

    Tsolaki, Elpiniki; Elpiniki, Tsolaki; Salviato, Elisabetta; Rocca, Tiberio; Braccini, Lucia; Galeotti, Roberto; Mascoli, Francesco

    2010-10-01

    Carotid pseudoaneurysms are a rare consequence of carotid surgery, trauma, and infection. Historically, carotid aneurysms and pseudoaneurysms were treated surgically. However, endovascular techniques have recently become a valid alternative for the treatment of carotid pseudoaneurysms. The case of a 57-year-old male patient with a pseudoaneurysm of the right internal carotid artery is described. The patient came to our unit with a painless and pulsatile mass in the neck, which was growing slowly. Five years earlier, he had undergone surgery on a saccular aneurysm located on the distal extracranial segment of the right internal carotid artery. The pseudoaneurysm was successfully treated with a heparin surface Viabahn stent-graft system (Gore AL, Flagstaff, AZ). Heparin surface stent-grafts can be used for the treatment of carotid lesions and may offer protection against intimal hyperplasia and thrombosis. Further studies are needed to evaluate the long-term results. Copyright © 2010 Annals of Vascular Surgery Inc. Published by Elsevier Inc. All rights reserved.

  10. Stentgraft Implantation for the Treatment of Postoperative Hepatic Artery Pseudoaneurysm

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pedersoli, F., E-mail: fpedersoli@ukaachen.de; Isfort, P.; Keil, S.

    PurposeHepatic artery pseudoaneurysms are a rare but potentially life-threatening complication of major pancreaticobiliary surgery. We evaluated the safety and efficacy of endovascular stentgraft implantation for the management of such vascular lesions.Materials and MethodsBetween May 2013 and October 2015, ten patients with postoperative hepatic artery pseudoaneurysm, of which eight presented with active hemorrhage, were treated with endovascular stentgraft implantation. All patients had undergone major pancreatic or hepatic surgery before (pylorus-preserving pancreaticoduodenectomy, pancreatectomy, hemihepatectomy, extended hemihepatectomy). The pseudoaneurysms were diagnosed 13–202 days after surgery and were associated with postsurgical complications (e.g., leakage of pancreaticojejunal anastomosis).ResultsIn 9/10 patients, the pseudoaneurysm was completely excluded viamore » stentgraft implantation. In 1/10 patient, the pseudoaneurysm ruptured during the procedure and was successfully treated by immediate open surgery. In 1/10 patient, a second intervention was performed after 6 days because of rebleeding; this was successfully treated by implantation of a second overlapping stentgraft. Mean follow-up time is 51 days. None of the patients died due to stentgraft- or aneurysm-related complications. Further episodes of hemorrhage were not observed. In one patient, clinically asymptomatic complete occlusion of the stentgraft was discovered at follow-up imaging.ConclusionStentgraft implantation is a safe and effective technique to treat hepatic artery pseudoaneurysms related to major pancreatic or hepatic surgery, especially in the setting of acute hemorrhage.« less

  11. Post-traumatic hepatic artery pseudo-aneurysm combined with subphrenic liver abscess treated with embolization.

    PubMed

    Sun, Long; Guan, Yong-Song; Wu, Hua; Pan, Wei-Min; Li, Xiao; He, Qing; Liu, Yuan

    2006-05-07

    A 23-year-old man with post-traumatic hepatic artery pseudo-aneurysm and subphrenic liver abscess was admitted. He underwent coil embolization of hepatic artery pseudo-aneurysm. The pseudo-aneurysm was successfully obstructed and subphrenic liver abscess was controlled. Super-selective trans-catheter coil embolization may represent an effective treatment for hepatic artery pseudo-aneurysm combined with subphrenic liver abscess in the absence of other therapeutic alternatives.

  12. The treatment of pseudoaneurysms with flow diverters after malignant otitis externa.

    PubMed

    Németh, Tamás; Szakács, László; Bella, Zsolt; Majoros, Valéria; Barzó, Pál; Vörös, Erika

    2017-12-01

    Background We report a case of bilateral malignant otitis externa complicated with bilateral petrous internal carotid artery pseudoaneurysms and their successful treatment with a flow diverter. Case report A 68-year-old woman with serious complications of type II diabetes mellitus had malignant otitis externa on the right side. She was treated with combined antibiotic therapy and underwent mastoidectomy for mastoiditis. She presented at our hospital with acute hemorrhage from the right external auditory canal. The emergency computed tomography (CT) angiography revealed a multiobulated pseudoaneurysm at the petrous segment of the right internal carotid artery. The pseudoaneurysm was treated with a 5 × 40-mm Surpass flow diverter. Three months later, she developed a malignant external otitis on the left side. As the infection progressed, a left-sided mastoiditis, a brain abscess, and a pseudoaneurysm at the petrous segment of the left internal carotid artery developed. The pseudoaneurysm caused bleeding from the left ear, and was treated with a 5 × 50-mm Surpass flow diverter. No recurrent bleeding was observed. Four months later, a follow-up angiography showed complete occlusion of the pseudoaneurysm on the left side, but a residual aneurysm could be detected on the right side. One year after the first intervention, the follow-up CT and magnetic resonance angiography revealed the complete occlusion of the aneurysms bilaterally. Conclusion The use of a flow diverter appears to be an efficient and safe method to occlude carotid pseudoaneurysms even in an inflammatory milieu.

  13. [Embolization as a treatment method in post-traumatic right hepatic artery pseudoaneurysm].

    PubMed

    Dobrowolska-Bak, Malgorzata; Brzegowy, Paweł; Urbanik, Andrzej

    2012-01-01

    A case of 42-year-old man with post-traumatic right hepatic artery pseudoaneurysm successfully treated by endovascular embolization with histoacrylate glue is presented. Despite coils are mostly used embolic material in pseudoaneurysm, embolization with histoacrylate glue can be highly effective and quick treatment modality for post-traumatic hepatic artery pseudoaneurysm, especially in cases when it is impossible to use standard materials.

  14. Femoral artery pseudoaneurysm as a complication of angioplasty. How can it be prevented?

    PubMed Central

    Gupta, Prabha Nini; Salam Basheer, Abdul; Sukumaran, Gireesh Gomaty; Padmajan, Sabin; Praveen, Satheesan; Velappan, Praveen; Nair, Bigesh Unnikrishnan; Nair, Sandeep Govindan; Kunjuraman, Usha Kumari; Madthipat, Unnikrishnan; R, Jayadevan

    2013-01-01

    Femoral pseudoaneurysm is a common complication of repeated femoral puncture during cardiac catheterisation. We describe here the development of femoral pseudoaneurysms in a patient with Takayasu's arteritis, which healed in response to conservative treatment, and review the literature on the prevention and treatment of femoral pseudoaneurysm. PMID:27326111

  15. Post-traumatic hepatic artery pseudo-aneurysm combined with subphrenic liver abscess treated with embolization

    PubMed Central

    Sun, Long; Guan, Yong-Song; Wu, Hua; Pan, Wei-Min; Li, Xiao; He, Qing; Liu, Yuan

    2006-01-01

    A 23-year-old man with post-traumatic hepatic artery pseudo-aneurysm and subphrenic liver abscess was admitted. He underwent coil embolization of hepatic artery pseudo-aneurysm. The pseudo-aneurysm was successfully obstructed and subphrenic liver abscess was controlled. Super-selective trans-catheter coil embolization may represent an effective treatment for hepatic artery pseudo-aneurysm combined with subphrenic liver abscess in the absence of other therapeutic alternatives. PMID:16718774

  16. Pseudoaneurysm of the medial superior genicular artery after arthroscopic partial meniscectomy.

    PubMed

    Lee, Kee Byoung; Song, Si Young; Kwon, Duck Joo; Shin, Jun; Paik, Sang Hoon

    2009-09-01

    We describe a case of 43-year-old man who had a pseudoaneurysm of the medial superior genicular artery after arthroscopic partial meniscectomy with standard anterolateral and anteromedial portals. Pseudoaneurysm of the medial superior genicular artery has been reported at the previous superomedial portal site after arthroscopy. Described herein is a unique case that involved the medial superior genicular artery at the previous anteromedial portal site after arthroscopy. The pseudoaneurysm was successfully treated with transcatheter embolization.

  17. Pseudoaneurysm of the Medial Superior Genicular Artery after Arthroscopic Partial Meniscectomy

    PubMed Central

    Lee, Kee Byoung; Kwon, Duck Joo; Shin, Jun; Paik, Sang Hoon

    2009-01-01

    We describe a case of 43-year-old man who had a pseudoaneurysm of the medial superior genicular artery after arthroscopic partial meniscectomy with standard anterolateral and anteromedial portals. Pseudoaneurysm of the medial superior genicular artery has been reported at the previous superomedial portal site after arthroscopy. Described herein is a unique case that involved the medial superior genicular artery at the previous anteromedial portal site after arthroscopy. The pseudoaneurysm was successfully treated with transcatheter embolization. PMID:19885054

  18. Endovascular treatment of life-threatening pseudoaneurysm of the hepatic artery after pancreaticoduodenectomy.

    PubMed

    Narumi, Shunji; Hakamda, Kenichi; Toyoki, Yoshikazu; Noda, Hiroshi; Sato, Toshiyuki; Morohashi, Hajime; Mitsui, Toshihito; Yoshihara, Syuichi; Sasaki, Mutsuo

    2007-01-01

    Pseudoaneurysm is a life-threatening complication after pancreaticoduodenectomy. An endovascular covered stent was employed for treatment of pseudoaneurysm of the common hepatic artery after pancreaticoduodenectomy. A 77-year-old female underwent pylorus-preserving pancreaticoduodenectomy for lower bile duct cancer. She complained of hematochezia but upper gastrointestinal endoscopy did not find a bleeding source. Angiography was performed and pseudoaneurysm of the common hepatic artery was discovered. Since no collateral perfusion to the liver was detected, embolization of the common hepatic artery was considered to expose the patient to the danger of severe hepatic dysfunction. Successful exclusion of the pseudoaneurysm was completed with an endovascular covered stent. Inflow of the hepatic artery was secured and no hepatic dysfunction developed. Patency of the stent was confirmed at 5 months follow-up. An endovascular covered stent can be a feasible modality for selected cases of the hepatic arterial pseudoaneurysm.

  19. Pseudoaneurysm as a complication of ankle arthroscopy.

    PubMed

    Mariani, P P; Mancini, L; Giorgini, T L

    2001-04-01

    We describe a case of pseudoaneurysm of the anterior tibial artery as a complication after arthroscopic ankle synovectomy, in which standard anterolateral and anteromedial portals were used. Pseudoaneurysm has been previously reported as a complication in ankle arthroscopy with the use of the anterocentral portal. Previously described anatomic variations of the tibial artery and its close relationship with the anterior ankle capsule may complicate arthroscopic surgery, especially when aggressive synovectomy is performed. Anterior tibial artery aneurysm is a rare complication of ankle arthroscopy, but its potential catastrophic sequelae must not be underestimated.

  20. Pseudoaneurysm of the medial inferior genicular artery after anterior cruciate ligament reconstruction.

    PubMed

    Mello, Wilson; de Brito, Wander Edney; Migon, Eduardo Zaniol; Borges, Alexandre

    2011-03-01

    We present a case of pseudoaneurysm formation of the medial inferior genicular artery after anterior cruciate ligament reconstruction. The patient presented with repeated knee hemarthrosis. He was diagnosed by means of magnetic resonance angiography and was treated by means of transluminal embolization. The patient's normal was normal after resolution of the vascular pathologic condition. Copyright © 2011 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  1. Biliary leakage due to a rapidly growing post-traumatic hepatic artery pseudoaneurysm: a case report.

    PubMed

    Hasegawa, Satoshi; Moriwaki, Yoshihiro; Uchida, Keiji; Kosuge, Takayuki; Yamamoto, Toshiro; Sugiyama, Mitsugi

    2004-01-01

    Post-traumatic hepatic pseudoaneurysms are rare. We report a very unusual case of bile duct injury complicated with an asymptomatic post-traumatic hepatic pseudoaneurysm. A previously healthy 17-year-old man sustained multiple traumas after a motorcycle accident. Post-traumatic hepatic pseudoaneurysms were detected after blunt liver injury. The rapid growth of the pseudoaneurysms in the hepatic hilus compressed the common hepatic bile duct and caused extrahepatic bile leakage at the lateral lobe. At first, the hepatic arterial pseudoaneurysms were embolized and bile leakage at the left lobe was treated conservatively. Finally, however, segment 2 and 3 partial liver resection should have been performed to stop the bile leakage. Post-traumatic pseudoaneurysm should be ruled out, in addition to the presence of biliary tract injury, if the intraperitoneal bile leakage appears after liver injury.

  2. Post-traumatic pseudoaneurysm of the common hepatic artery with duodenal fistula

    PubMed Central

    Matsumoto, Cal; Wayne, Michael; Schwartz, Myron E

    2002-01-01

    Background Post-traumatic pseudoaneurysm of the hepatic artery is rare, especially after blunt abdominal trauma; an even more rare occurrence is enteric fistulisation. Case outline A 29-year-old man was admitted with an acute episode of upper gastrointestinal bleeding three months after blunt abdominal trauma and was found to have an hepatic artery pseudoaneurysm with duodenal fistula. Surgical treatment was by ligature of the artery and duodenal closure with omental patch. Discussion There is one previous case report of hepatic artery pseudoaneurysm as a delayed complication of blunt abdominal trauma. The presence of a haematoma in the hepatoduodenal ligament after blunt trauma should raise the suspicion of hepatic artery injury, and surgical exploration may prevent the subsequent development of pseudoaneurysm. CT scan has become an important instrument both in diagnosis and in surgical planning. PMID:18332952

  3. Endovascular closure of ascending aortic pseudoaneurysm with a type II Amplatzer vascular plug.

    PubMed

    De Boo, Diederick W; Mott, Nigel; Kavnoudias, Helen; Walton, Antony; Lyon, Stuart M

    2014-05-01

    A 71-year-old man initially presented with an asymptomatic, incidentally detected ascending aortic pseudoaneurysm 25 years following aortic root repair with mechanical aortic valve replacement. This pseudoaneurysm was previously treated with coil embolization but due to coil impaction it reopened 8 years later. Endovascular closure of the pseudoaneurysm was achieved with the off-label use of a type II Amplatzer vascular plug.

  4. Non-traumatic right hepatic artery pseudoaneurysm: an unusual cause of hemobilia and obstructive jaundice.

    PubMed

    Alvi, Abdul Rehman; Bibi, Shahida; Zia-ur-Rehman; Khan, Salma

    2009-12-01

    Most hepatic artery pseudoaneurysms (HAPA) are post traumatic, and non-traumatic pseudoaneurysm is rarely reported. It is a potentially life threatening vascular disorder and difficult to diagnose before rupture. Early diagnosis and prompt nonoperative intervention of this lesion could be life saving. The authors report the case of a patient with hemobilia caused by ruptured right hepatic artery pseudoaneurysm and subsequently developed right hepatic duct stricture, which has not been reported previously. This patient was successfully treated with endovascular stent graft of pseudoaneurysm and endoscopic stenting of right hepatic duct stricture.

  5. Percutaneous closure of a large ascending aortic pseudoaneurysm.

    PubMed

    Nogueira, Marta Afonso; Fiarresga, António; de Sousa, Lídia; Galrinho, Ana; Santos, Ninel; Nobre, Isabel; Laranjeira, Álvaro; Cruz Ferreira, Rui

    2016-02-01

    Pseudoaneurysm of the ascending aorta is a rare complication, usually after thoracic surgery or trauma. Since surgical repair is associated with very high morbidity and mortality, percutaneous closure has been described as an alternative. In this regard, we present a case in which a symptomatic large pseudoaneurysm of the ascending aorta was treated percutaneously due to the high surgical risk. Despite the technical difficulties, this procedure had a good final result followed by clinical success. Copyright © 2016 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

  6. Two Cases of Postmyomectomy Pseudoaneurysm Treated by Transarterial Embolization

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ito, Nobutake, E-mail: nobutake@rad.med.keio.ac.jp; Natimatsu, Yoshiaki; Tsukada, Jitsuro

    Pseudoaneurysm resulting from hysteroscopic myomectomy is a rare clinical situation, and interventional radiologists are not traditionally involved in the management. To our knowledge, endovascular treatment of a pseudoaneurysm resulting from hysteroscopic myomectomy has not yet been reported in the English-language literature. Here, two such cases are reported, including one of a woman who later became pregnant. The case is unique because little is known about the influence of unilateral coil embolization of the uterine artery on fertility.

  7. Endovascular treatment of the extracranial carotid pseudoaneurysms resulting from stab penetrating injury using overlapping bare stents.

    PubMed

    Pan, Yao-hua; Lin, Yong; Ding, Sheng-hao; Chen, Lei; Liang, Yu-ming; Yin, Yu-hua; Bao, Ying-hui; Gao, Guo-Yi; Qiu, Yong-ming; Jiang, Ji-yao

    2014-05-01

    Injury pertaining to the common carotid artery may result in complete or partial arterial transection, pseudoaneurysms, or arteriovenous connections. Endovascular treatment option of the pseudoaneurysm has already been established with favorable success rate and minimal morbidity. Our purpose is to report one 18-year-old male patient having 2 traumatic pseudoaneurysms as a result of penetrating stab injury in the extracranial common carotid. The patient was successfully treated using 2 overlapping bare-metal stents. The 2 common carotid pseudoaneurysms had different degree inflow angles defined as the space between the lines indicating the direction of blood flow from the parent artery and through the aneurysmal neck to the dome. Computed tomography angiography was utilized to follow the evolution of the pseudoaneurysms until total occlusion was demonstrated. The treatment modality used in this report represents an alternative approach of the endovascular treatment for the extracranial carotid pseudoaneurysm.

  8. Hepatic artery pseudoaneurysm with hemobilia following angioplasty after liver transplantation.

    PubMed

    Narumi, S; Osorio, R W; Freise, C E; Stock, P G; Roberts, J P; Ascher, N L

    1998-12-01

    A 58-yr-old female with primary biliary cirrhosis underwent an uncomplicated orthotopic liver transplantation. Elevated liver function tests 2 months post-transplantation were evaluated with Doppler ultrasound and a hepatic artery stricture was documented. The hepatic artery stenosis was treated with angioplasty. She developed hemobilia 1 d after the procedure, which was confirmed by angiography. Emergent exploratory laparotomy revealed a pseudoaneurysm at the hepatic artery anastomosis. The pseudoaneurysm was resected and the proper hepatic artery of the graft was anastomosed to the splenic artery of the host using preserved homograft. Her post-operative course was uneventful and liver function tests returned to normal quickly after the surgery. This report will discuss the unusual nature of this complication, and review the problem of hemobilia and pseudoaneurysms in liver transplant recipients.

  9. Pseudoaneurysm of the Radial Artery After a Bicycle Fall.

    PubMed

    Ratschiller, Thomas; Müller, Hannes; Schachner, Thomas; Zierer, Andreas

    2018-07-01

    We report a case of a 64-year-old man who developed a painful pulsatile mass in the distal forearm after a bicycle fall with fracture of the wrist. Ultrasonography confirmed a 2.5-cm large pseudoaneurysm of the radial artery. The patient underwent surgical exploration. The pseudoaneurysm was resected and the defect in the arterial wall was reconstructed with an autologous saphenous vein patch. We suggest that the double arterial supply of the hand should be preserved whenever possible.

  10. Post-traumatic hepatic artery pseudoaneurysm treated with endovascular embolization and thrombin injection.

    PubMed

    Francisco, Lloret Estañ; Asunción, López Conesa; Antonio, Capel Alemán; Ricardo, Robles Campos; Manuel, Reus Pintado; Caridad, Marín Hernández

    2010-02-27

    Post-traumatic hepatic artery pseudoaneurysm is uncommon, appearing in approximately 1% of hepatic trauma cases. Most are extrahepatic (80%) and have a late onset. Although they are usually asymptomatic, they should always be treated becasue of the high risk of complications, especially breakage. Currently the treatment of choice is endovascular embolization with coils or the exclusion of the pseudoaneurysm using other intravascular devices. Recently there have been accounts of a treatment that combines embolization with coils and image-guided percutaneous human thrombin injection. We present a case of post-traumatic hepatic artery pseudoaneurysm that was successfully treated using this combined technique.

  11. Post-traumatic hepatic artery pseudoaneurysm treated with endovascular embolization and thrombin injection

    PubMed Central

    Francisco, Lloret Estañ; Asunción, López Conesa; Antonio, Capel Alemán; Ricardo, Robles Campos; Manuel, Reus Pintado; Caridad, Marín Hernández

    2010-01-01

    Post-traumatic hepatic artery pseudoaneurysm is uncommon, appearing in approximately 1% of hepatic trauma cases. Most are extrahepatic (80%) and have a late onset. Although they are usually asymptomatic, they should always be treated becasue of the high risk of complications, especially breakage. Currently the treatment of choice is endovascular embolization with coils or the exclusion of the pseudoaneurysm using other intravascular devices. Recently there have been accounts of a treatment that combines embolization with coils and image-guided percutaneous human thrombin injection. We present a case of post-traumatic hepatic artery pseudoaneurysm that was successfully treated using this combined technique. PMID:21160978

  12. Endovascular Treatment of a Vertebral Artery Pseudoaneurysm in a Drug User

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mourikis, Dimitrios; Chatziioannou, Achilleas; Doriforou, Ortansia

    A 26-year-old drug abuser who presented with sepsis was found to have a pseudoaneurysm in the left vertebral artery. This aneurysm was presumed to be post-traumatic, since the patient reported multiple attempts to inject drugs in the left jugular vein 15 days prior to admission. The pseudoaneurysm was treated effectively with stent-graft placement.

  13. Interventional Radiology in the Management of Visceral Artery Pseudoaneurysms: A Review of Techniques and Embolic Materials

    PubMed Central

    Venkatesh, Hosur Ananthashayana; Gamanagatti, Shivanand; Garg, Pramod; Srivastava, Deep Narayan

    2016-01-01

    Visceral artery pseudoaneurysms occur mostly as a result of inflammation and trauma. Owing to high risk of rupture, they require early treatment to prevent lethal complications. Knowledge of the various approaches of embolization of pseudoaneurysms and different embolic materials used in the management of visceral artery pseudoaneurysms is essential for successful and safe embolization. We review and illustrate the endovascular, percutaneous and endoscopic ultrasound techniques used in the treatment of visceral artery pseudoaneurysm and briefly discuss the embolic materials and their benefits and risks. PMID:27134524

  14. Sinus of Valsalva Pseudoaneurysm as a Sequela to Infective Endocarditis.

    PubMed

    Lee, Chin C; Siegel, Robert J

    2016-02-01

    Pseudoaneurysm is an uncommon sequela of infective endocarditis. We treated a 44-year-old man who had an active case of group B streptococcal infective endocarditis of the aortic valve despite no evidence of valvular dysfunction or vegetation on his initial transesophageal echocardiogram. After completing 6 weeks of intravenous antibiotic therapy, the patient developed a sinus of Valsalva pseudoaneurysm and severe aortic regurgitation caused by partial detachment of the left coronary cusp. We used a pericardial patch to close the pseudoaneurysm and repair the coronary cusp. This case shows the importance of routine clinical follow-up evaluation in infective endocarditis, even after completion of antibiotic therapy. Late sequelae associated with infective endocarditis or its therapy include recurrent infection, heart failure caused by valvular dysfunction (albeit delayed), and antibiotic toxicity such as aminoglycoside-induced nephropathy and vestibular toxicity.

  15. Transcatheter device closure of pseudoaneurysms of the left ventricular wall: An emerging therapeutic option.

    PubMed

    Madan, Tarun; Juneja, Manish; Raval, Abhishek; Thakkar, Bhavesh

    2016-02-01

    Left ventricular pseudoaneurysm is a rare but serious complication of acute myocardial infarction and cardiac surgery. While surgical intervention is the conventional therapeutic option, transcatheter closure can be considered in selected patients with suitable morphology of the pseudoaneurysm. We report a case of successful transcatheter closure of a left ventricular pseudoaneurysm orifice and isolation of the sac using an Amplatzer septal occluder. Copyright © 2016 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

  16. Progressive paralyzing sciatica revealing a pelvic pseudoaneurysm a year after hip surgery in a 12yo boy.

    PubMed

    Boulouis, Grégoire; Shotar, Eimad; Dangouloff-Ros, Volodia; Janklevicz, Pierre-Henri; Boddaert, Nathalie; Naggara, Olivier; Brunelle, Francis

    2016-01-01

    Identifying extra spinal causes of a lumbar radiculopathy or polyneuropathy can be a tricky diagnosis challenge, especially in children. Among them, traumatic or iatrogenic pseudoaneurysms of iliac arteries have been seldom reported, in adults' series. The authors report an unusual case of progressive paralyzing left sciatica and lumbar plexopathy in a 12 years old boy, 12 months after a pelvic osteotomy for bilateral hip luxation secondary to osteochondritis dissecans. Spine MRI and pelvic CT angiography revealed a giant internal iliac artery pseudoaneurysm, enclosed in a chronic hematoma. The patient was successfully treated with endovascular coil embolization, and subsequent surgical hematoma evacuation. However, three months after treatment, neurological recovery was incomplete. This case highlights the importance of a rapid and extensive diagnosis work up of all causes of lower limb radiculopathies in children, including pelvic arteries lesions especially after pelvic surgery to avoid therapeutic delays that may jeopardize the chances of neurological recovery. Copyright © 2015 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.

  17. Splenic artery embolization for post-traumatic splenic artery pseudoaneurysm in children.

    PubMed

    Yardeni, Dani; Polley, Theodore Z; Coran, Arnold G

    2004-08-01

    Although rare, traumatic splenic artery pseudoaneurysm (SAP) can be life threatening. The diagnostic approaches as well as the methods of treatment of SAP are yet to be determined. We present the case of a 10-year-old boy treated conservatively for a grade III blunt splenic injury (BSI). The child was discharged to home after a 5-day uneventful hospitalization but was found on routine follow-up CT scan to have a large SAP. The pseudoaneurysm was successfully angiographically embolized and subsequent abdominal CT demonstrated successful resolution of the pseudoaneurysm with a small residual splenic cyst. We reviewed the eight cases of post-traumatic SAP in children that have been published in the English literature. Unlike SAP in adult patients, the severity of the splenic injury does not have predictive value for development of SAP in children. Abdominal pain was the most frequent symptom of SAP, but three children were asymptomatic at the time of diagnosis. Therefore, the possibility of SAP should be investigated even in the asymptomatic child with mild splenic injury. When a splenic pseudoaneurysm is diagnosed, we believe splenic artery embolization is indicated.

  18. [Femoral artery pseudoaneurysms encountered in orthopedics and traumatology].

    PubMed

    Raherinantenaina, F; Rajaonanahary, T M A; Rakoto Ratsimba, H N

    2015-12-01

    Most published articles regarding orthopedic- and trauma-related femoral artery pseudoaneurysms (FAPs) are case reports in English. Reported cases are often associated with a literature review but actually provide little robust data. We wanted to summarize the current knowledge on diagnostic and therapeutic features of these FAPs. A new case of superficial FAP is described followed by a review of the literature. A bibliographic search was performed online (PubMed, ScinceDirect) from 1964 to 2015 using the descriptors "traumatic femoral pseudoaneurysm, orthopedic surgery, osteochondroma". A total of 64 cases of FAPs was analyzed. There were 50 men with an average age of 40.72±26.45 years old. The most common clinical presentation was painful swelling (34%). Arteriography was the commonest radiological investigation used (63%). The main etiologies were orthopedic injuries (47%), surgery of the upper thigh (30%) and femoral osteochondromas (23%). Arterial injuries included superficial femoral (47%) and profunda femoris artery (50%). The treatment was open surgery (56%) or endovascular repair (36%). Deep femoral artery and its branches were embolized (47%) or ligated (38%). Endovascular stenting was performed in 30% of posttraumatic FAPs. All FAPs relating to osteochondromas were repaired surgically. Postoperative courses were uneventful in 95% of patients. Endovascular embolization is preferred in management of postsurgical FAPs which have usually involved the deep femoral artery. Endovascular stenting graft may be proposed for posttraumatic FAPs, for which the superficial femoral trunk is the most often involved vessel. Surgical repair should be performed when endovascular stenting graft is not feasible. Surgical repair is mandatory for all FAPs secondary to traumatic exostoses. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  19. Efficacy of a Self-Expandable Porous Stent as the Sole Curative Treatment for Extracranial Carotid Pseudoaneurysms.

    PubMed

    Chen, Peng Roc; Edwards, Nancy J; Sanzgiri, Aditya; Day, Arthur L

    2016-04-01

    Extracranial carotid pseudoaneurysms are uncommon vascular lesions. Even with conservative management complications can happen, such as delayed cerebral embolization or symptoms due to flow limitation. Although endovascular therapy can be curative, literature demonstrating a preferred technique is scant. Our goal was to evaluate the use of 1 technique only-the deployment of overlapping self-expandable porous stents-to treat a series of extracranial carotid pseudoaneurysms. From 2008 to 2014, 14 consecutive cases of symptomatic extracranial carotid pseudoaneurysms were managed with single or multilayer porous stents at our institution. Each patient underwent a standardized angiographic follow-up at 6 months. Twelve patients also received a follow-up computed tomography angiogram at 12 months, and yearly thereafter (median radiographic follow-up, 38 months). The total clinical follow-up period ranged between 6 and 69 months (median, 46 months). In our series, each of the extracranial carotid pseudoaneurysms appeared to be the result of carotid artery dissection with associated carotid stenosis at the origin of every pseudoaneurysm. Endovascular treatment consisted of 1-3 layers of self-expandable porous stents placed without balloon angioplasty. Immediately after stenting angiographic images were notable for stagnant opacification of the pseudoaneurysm through the stent(s). All pseudoaneurysms were completely obliterated by the 6-month follow-up angiogram and remained so throughout the radiographic follow-up period. Complications were minimal, consisting of 1 patient developing a mild Horner's syndrome after treatment that resolved during clinical follow-up. Extracranial carotid pseudoaneurysms can be successfully obliterated with the use of porous, self-expandable stents. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Postpartum Hemorrhage Resulting from Pelvic Pseudoaneurysm: A Retrospective Analysis of 588 Consecutive Cases Treated by Arterial Embolization

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dohan, Anthony, E-mail: anthony.dohan@lrb.aphp.fr; Soyer, Philippe, E-mail: philippe.soyer@lrb.aphp.fr; Subhani, Aqeel, E-mail: drsubhani07@gmail.com

    Objective: This study was designed to determine the incidence of arterial pseudoaneurysm in patients presenting with postpartum hemorrhage (PPH), to analyze the angiographic characteristics of pseudoaneurysms that cause PPH, and to evaluate the effectiveness of pelvic arterial embolization for the treatment of this condition.Study designEighteen women with pelvic arterial pseudoaneurysm were retrieved from a series of 588 consecutive patients with PPH treated by arterial embolization. Clinical files, angiographic examinations, and procedure details were reviewed. Results: The incidence of pseudoaneurysm was 3.06 % (18/588; 95 % confidence interval (CI): 1.82-4.8 %). A total of 20 pseudoaneurysms were found; 15/20 (75 %)more » were located on the uterine arteries. Angiography revealed extravasation of contrast material from pseudoaneurysm indicating rupture in 9 of 18 (50 %) patients. Arterial embolization was performed using gelatin sponge alone in 12 of 18 (67 %) patients or in association with metallic coils in 5 of 18 (28 %) patients or n-butyl-2-cyanoacrylate in 1 of 18 (6 %) patients. Arterial embolization allowed controlling the bleeding in all patients after one or two embolization sessions in 17 of 18 (94 %) and 1 of 18 patients (6 %) respectively, without complications, obviating the need for further surgery. Conclusions: Pseudoaneurysm is rarely associated with PPH. Arterial embolization is an effective and safe procedure for the treatment of PPH due to uterine or vaginal artery pseudoaneurysm. Our results suggest that gelatin sponge is effective for the treatment of ruptured pseudoaneurysms, although we agree that our series does not contain sufficient material to allow drawing definitive conclusions with respect to the most effective embolic material.« less

  1. Endovascular management of iatrogenic cervical internal carotid artery pseudoaneurysm in a 9-year-old child: Case report and literature review.

    PubMed

    Pinzón, Martín; Lobelo, Nelson Oswaldo; Rodríguez, María Claudia; Villamor, Perla; Otoya, Ana María

    2017-04-01

    Extracranial internal carotid artery (ICA) pseudoaneurysms are uncommon in the pediatric population and are usually secondary to direct trauma to the vessel. Treatment options include surgery (ligation), anticoagulation therapy and endovascular treatment. Endovascular covered stents have shown good results in adult populations, resulting in occlusion of the aneurysm and preservation of the artery without significant complications. However, there have been only limited reports in the literature reporting endovascular carotid stent placement in the pediatric population. We report a case of a 9-year-old boy patient, who developed a cervical ICA pseudoaneurysm after a parapharyngeal tumor resection. He was successfully treated by primary endovascular covered stent placement. During a follow-up of 6 months the patient has been asymptomatic, without any adverse event. Additionally, a literature review is done. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. An alternative noninvasive technique for the treatment of iatrogenic femoral pseudoaneurysms: stethoscope-guided compression.

    PubMed

    Korkmaz, Ahmet; Duyuler, Serkan; Kalayci, Süleyman; Türker, Pinar; Sahan, Ekrem; Maden, Orhan; Selçuk, Mehmet Timur

    2013-06-01

    latrogenic femoral pseudoaneurysm is a well-known vascular access site complication. Many invasive and noninvasive techniques have been proposed for the management of this relatively common complication. In this study, we aimed to evaluate efficiency and safety of stethoscope-guided compression as a novel noninvasive technique in the femoral pseudoaneurysm treatment. We prospectively included 29 consecutive patients with the diagnosis of femoral pseudoaneurysm who underwent coronary angiography. Patients with a clinical suspicion of femoral pseudoaneurysm were referred to colour Doppler ultrasound evaluation. The adult (large) side of the stethoscope was used to determine the location where the bruit was best heard. Then compression with the paediatric (small) side of the stethoscope was applied until the bruit could no longer be heard and compression was maintained for at least two sessions. Once the bruit disappeared, a 12-hour bed rest with external elastic compression was advised to the patients, in order to prevent disintegration of newly formed thrombosis. Mean pseudoaneurysm size was 1.7 +/- 0.4 cmx 3.0 +/- 0.9 cm and the mean duration of compression was 36.2 +/- 8.5 minutes.Twenty-six (89.6%) of these 29 patients were successfully treated with stethoscope-guided compression. In 18 patients (62%), the pseuodoaneurysms were successfully closed after 2 sessions of 15-minute compression. No severe complication was observed. Stethoscope-guided compression of femoral pseudoaneurysms is a safe and effective novel technique which requires less equipment and expertise than other contemporary methods.

  3. Post-traumatic hepatic arterial pseudoaneurysm and arterioportal shunt.

    PubMed

    Maes, J; D'Archambeau, O; Snoeckx, A; Op de Beeck, B; Voormolen, M; Parizel, P M

    2010-01-01

    The authors report the case of a 21-year-old man who suffered from a blunt abdominal trauma. Initial imaging revealed a liver laceration at the right lobe, a perirenal hematoma of the right kidney and a hematoma of the right adrenal gland. Follow-up MDCT-scan on day 10 after admission showed at the arterial-phase contrast-enhanced study perfusion alterations and two hepatic pseudoaneurysms. The diagnosis of pseudoaneurysm was confirmed and treated angiographically with superselective coil embolization. A follow-up CT-scan on day 17 showed at a nontreated area an arterioportal shunt and a wedge-shaped transient hepatic parenchymal enhancement. This was confirmed angiographically and subsequently treated with coil embolization.

  4. Giant pseudoaneurysm from Vieussens' arterial ring.

    PubMed

    Kocica, Mladen J; Vranes, Mile R; Djukic, Petar L; Mikic, Aleksandar Dj; Velinovic, Milos M; Havelka, Marija; Kanjuh, Vladimir I

    2004-11-01

    A giant coronary pseudoaneurysm of uncertain cause, arising from Vieussens' arterial ring, was preoperatively diagnosed in an oligosymptomatic female patient. Successful off-pump surgical excision without additional bypass grafting was performed. Difficulties in diagnostic algorithm, as well as possible cause and extremely rare localization were discussed.

  5. Pseudoaneurysm with Arteriovenous Fistula after Arthroscopic Procedure: A Rare Complication of Arthroscopy

    PubMed Central

    Jin, Moran; Lee, Yang-Haeng; Yoon, Young Chul; Han, Il-Yong; Park, Kyung-Taek; Wi, Jin Hong

    2015-01-01

    Pseudoaneurysm with arteriovenous fistula is a rare complication of arthroscopy, and can be diagnosed by ultrasonography, computed tomography, magnetic resonance imaging, or angiography. This condition can be treated with open surgical repair or endovascular repair. We report our experience with the open surgical repair of a pseudoaneurysm with an arteriovenous fistula in a young male patient who underwent arthroscopy five months previously. PMID:26290846

  6. Aspergillus terreus infection of pseudoaneurysm of aortofemoral vascular graft with contiguous vertebral osteomyelitis.

    PubMed

    Glotzbach, R E

    1982-02-01

    This is a case report of a patient who developed several unusual complications of an aortofemoral vascular graft. These were thrombosis, pseudoaneurysm, and infection. There was an Aspergillus terreus infection of the pseudoaneurysm of the vascular prosthesis. A contiguous vertebral osteomyelitis due to A. terreus subsequently developed. This represented a localized, invasive form of aspergillosis.

  7. Infrarenal Abdominal Aortic Pseudoaneurysm: Is It a Real Emergency?

    PubMed Central

    Massara, Mafalda; Prunella, Roberto; Gerardi, Pasquale; Lillo, Antonio; De Caridi, Giovanni; Serra, Raffaele; Notarstefano, Stefano; Impedovo, Giovanni

    2017-01-01

    Abdominal aortic pseudoaneurysm is a rare but life-threatening condition that occurs due to penetrating or blunt trauma. Clinical manifestations are variable, and the time interval from the initial trauma to diagnosis is variable. A prompt diagnosis and an aggressive management approach are required to avoid catastrophic complications. Possible treatment options are open surgical repair, endovascular repair, pseudoanerysmal sac thrombosis induction through direct thrombin injection, and coil embolization. Here, we present the case of a 75-year-old man affected by an infrarenal abdominal aortic pseudoaneurysm presenting with abdominal and lumbar pain for 3 days, who was successfully treated with an endograft. PMID:29515707

  8. Selective transcatheter embolization for treatment of post-traumatic hepatic artery and portal vein pseudoaneurysms.

    PubMed

    Laopaiboon, Vallop; Aphinives, Chalida; Pugkem, Ake; Thummaroj, Jureerat; Puttharak, Warinthorn; Soommart, Yamuna

    2006-02-01

    The authors report a case of post-traumatic hepatic artery and portal vein pseudoaneurysms caused by blunt abdominal trauma, with multiple organ injuries including liver laceration. Abdominal spiral CT, CDS and DSA were performed to confirm the diagnosis. Both pseudoaneurysms were treated successfully with selective transcatheter embolization.

  9. Traumatic pseudoaneurysm of the intracavernous ICA presenting with massive epistaxis: imaging diagnosis and endovascular treatment.

    PubMed

    Han, M H; Sung, M W; Chang, K H; Min, Y G; Han, D H; Han, M C

    1994-03-01

    Traumatic pseudoaneurysm of the intracavernous internal carotid artery (ICA) is a very rare cause of epistaxis but is a life-threatening clinical situation when left untreated. The authors have experienced four cases of traumatic pseudoaneurysm involving the intracavernous ICA. Delayed massive epistaxes developed 1 to 8 months after trauma and initial transient epistaxis in all four patients. Three of the cases were successfully managed by the detachable balloon occlusion (DBO) of the ICA along with the aneurysm openings. In one case, a large pseudoaneurysm destroying a large area of the central skull base with peripheral blood clot was demonstrated on computed tomography, magnetic resonance imaging, and angiography; this patient died due to massive epistaxis before the trial of DBO. Imaging findings of pseudoaneurysms involving the intracavernous ICA in the four cases are described, and the role of endovascular treatment is discussed.

  10. Successful Kissing Balloon Expandable Stent Graft Treatment for a Right Common Carotid Pseudoaneurysm Caused by Tracheotomy.

    PubMed

    Agyei, Justice O; Alvarez, Cynthia; Iqbal, Azher; Fanous, Andrew A; Siddiqui, Adnan H

    2018-06-01

    A rare complication following tracheotomy is common carotid artery (CCA) pseudoaneurysm. Treatment modalities for CCA pseudoaneurysm include surgical repair and single-artery balloon-covered stent graft technique. We describe successful treatment of tracheotomy-related CCA pseudoaneurysm with the "kissing balloon" expandable stent graft technique. We successfully implemented the kissing balloon expandable stent graft technique for treatment of a large, narrow-necked, bilobed CCA pseudoaneurysm that arose owing to a tracheotomy complication. The pseudoaneurysm was detected while performing a diagnostic angiogram of the aortic arch and surrounding vessels. The stent was deployed while the 2 balloons were introduced in a kissing manner such that they faced one another to avoid occlusion of either branch of the innominate artery coming into contact; 1 balloon was inflated at the origin of the right subclavian artery, and the other was inflated at the right innominate artery simultaneously. The pseudoaneurysm was successfully contained; normal blood flow was restored in the CCA. The balloons were deflated and withdrawn. The patient remained neurologically intact after the procedure. The kissing balloon technique is a safe and effective alternative to surgical repair, as it prevents morbidities associated with the surgical procedure. Also, this technique decreases the risk of major side-branch occlusion associated with the single-artery balloon-covered stent graft technique. Copyright © 2018 Elsevier Inc. All rights reserved.

  11. Treatment of tuberculous aortic pseudoaneurysm associated with vertebral tuberculosis: A case series and a literature review.

    PubMed

    Xue, Jing; Yao, Yimin; Liu, Limin

    2018-04-01

    Tuberculous aortic pseudoaneurysm associated with vertebral tuberculosis is a rare disease but with very high mortality. We review the literature and find 19 reports with 22 patients. Here we report three cases with vertebral tuberculosis, who also have tuberculous pseudoaneurysm of the aorta. These patients were treated by different methods. We try to analyze the epidemiology, pathogenesis, presentation, and management of this disease to find the best treatment. The patients presented with different symptoms such as pain (chest, abdominal or back), fever, blood volume reduction or hemorrhagic shock symptoms. Large mass also could be observed by imaging. In addition to clinical manifestations, enhanced computed tomography or magnetic resonance imaging could also help the diagnosis of this disease. Tuberculous aortic pseudoaneurysm associated with vertebral tuberculosis. Three patients were treated with anti-tuberculosis(TB) drugs or combined with different sequences surgical treatment: Case 1 refused to receive pseudoaneurysm surgery and only had anti-TB drug treatment; Case 2 received thoracic spinal surgery first; Case 3 received endovascular stent grafting. Two patients (case 1 and case 2) who refused to undergo aneurysm surgery died. The last patient (case 3) underwent endovascular repair and antibiotic therapy for tuberculosis, and the postoperative course was uneventful; the patient recovered and survived. Once the diagnosis of tuberculous pseudoaneurysm is confirmed, surgical treatment should be provided immediately combined with anti-tuberculosis drugs. The aim of the treatment is to save lives, prevent relapse, and facilitate the return to normal life, regardless of the size of the pseudoaneurysm. The pseudoaneurysm should be treated first to prevent aneurysm rupture before the vertebral tuberculosis surgery.

  12. Subclavian Artery Pseudoaneurysm in an Unusual Case of Digital Gangrene.

    PubMed

    Majhi, Bhuban; Pal, Nandita

    2017-01-01

    A young male patient presented at a tertiary care hospital with cold and bluish left upper limb accompanied with digital gangrene arousing suspicion of peripheral vascular disease. History did not reveal any high-risk behavior. Clinical examination and subsequent investigations lead to the diagnosis of acute infective endocarditis of native aortic valve along with peripheral embolism caused by methicillin-resistant Staphylococcus aureus . Fogarty's balloon embolectomy was done following which patient developed pseudoaneurysm of the left subclavian artery. These iatrogenic sequelae were managed with the resection of the pseudoaneurysm and prolonged antibiotic therapy as per the culture and sensitivity report.

  13. Stent-Graft Treatment for Bleeding Superior Mesenteric Artery Pseudoaneurysm After Pancreaticoduodenectomy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Suzuki, Kojiro, E-mail: kojiro@med.nagoya-u.ac.jp; Mori, Yoshine; Komada, Tomohiro

    We report two cases of intraperitoneal bleeding from superior mesenteric artery (SMA) pseudoaneurysm after pancreaticoduodenectomy for pancreatic head carcinoma. In both cases, a stent-graft was deployed on the main SMA to exclude pseudoaneurysm and to preserve blood flow to the bowel. Bleeding stopped after the procedure. One patient was able to be discharged but died from carcinoma recurrence 4 months later. The other patient died of sepsis and stent-graft infection 5 months later. These patients remained free of intraperitoneal rebleeding during the follow-up period.

  14. Endovascular Treatment of a Giant Superior Mesenteric Artery Pseudoaneurysm Using a Nitinol Stent-Graft

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gandini, Roberto; Pipitone, Vincenzo; Konda, Daniel, E-mail: danielkonda@yahoo.com

    2005-01-15

    A 68-year-old woman presenting with gastrointestinal bleeding (hematocrit 19.3%) and in a critical clinical condition (American Society of Anesthesiologists grade 4) from a giant superior mesenteric artery pseudoaneurysm (196.0 x 131.4 mm) underwent emergency endovascular treatment. The arterial tear supplying the pseudoaneurysm was excluded using a 5.0 mm diameter and 31 mm long monorail expanded polytetrafluoroethylene (ePTFE)-covered self-expanding nitinol stent. Within 6 days of the procedure, a gradual increase in hemoglobin levels and a prompt improvement in the clinical condition were observed. Multislice CT angiograms performed immediately, 5 days, 30 days and 3 months after the procedure confirmed the completemore » exclusion of the pseudoaneurysm.« less

  15. Internal Carotid Artery Pseudoaneurysm after Tonsillectomy Treated by Endovascular Approach

    PubMed Central

    Raffin, C.N.; Montovani, J.C.; Neto, J.M.P.; Campos, C.M.S.; Piske, R.L.

    2002-01-01

    Summary Surgery on the head and neck region may be complicated by vascular trauma, caused by direct injury on the vascular wall. Lesions of the arteries are more dangerous than the venous one. The traumatic lesion may cause laceration of the artery wall, spasm, dissection, arteriovenous fistula, occlusion or pseudoaneurysm. We present a case of a child with a giant ICA pseudoaneurysm after tonsillectomy, manifested by pulsing mass and respiratory distress, which was treated by endovascular approach, occluding the lesion and the proximal artery with Histoacryl. We reinforce that the endovascular approach is the better way to treat most of the traumatic vascular lesions. PMID:20594516

  16. Traumatic Inferior Gluteal Artery Pseudoaneurysm and Arteriovenous Fistula Managed with Emergency Transcatheter Embolization

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Keeling, A. N.; Naughton, P. A.; Leahy, A. L.

    We present a case of blunt trauma to the buttock resulting in an inferior gluteal artery pseudoaneurysm and arteriovenous fistula. The characteristic diagnostic features on CT angiography and digital subtraction angiography (DSA), along with the emergency percutaneous management of this traumatic vascular injury, are described. A review of the literature demonstrates inferior gluteal artery pseudoaneurysm is a rare condition, while successful treatment with glue embolization is previously unreported.

  17. Symptomatic Post Endarterectomy Common Carotid Artery Pseudoaneurysm Treated with Combination of Flow Diverter Implantation and Carotid Stenting

    PubMed Central

    Imbarrato, Greg; Gordhan, Ajeet

    2018-01-01

    A 74-year-old male developed cervical carotid artery psuedoaneurysm 8 months after carotid endarterectomy. The patient was successfully managed with dual implantation of flow-diverter and conventional carotid stent. Flow-diverter was placed across the neck of pseudoaneurysm to provide flow diversion while carotid stent was implanted within the lumen of the expanded flow-diverter to approximate and hold the flow diverter proximal and distal to the pseudoaneurysm. Follow-up ultrasonography revealed complete resolution of the pseudoaneurysm. PMID:29535899

  18. Monomer-dependent secondary nucleation in amyloid formation.

    PubMed

    Linse, Sara

    2017-08-01

    Secondary nucleation of monomers on the surface of an already existing aggregate that is formed from the same kind of monomers may lead to autocatalytic amplification of a self-assembly process. Such monomer-dependent secondary nucleation occurs during the crystallization of small molecules or proteins and self-assembled materials, as well as in protein self-assembly into fibrous structures. Indications of secondary nucleation may come from analyses of kinetic experiments starting from pure monomers or monomers supplemented with a low concentration of pre-formed aggregates (seeds). More firm evidence requires additional experiments, for example those employing isotope labels to distinguish new aggregates arising from the monomer from those resulting from fragmentation of the seed. In cases of amyloid formation, secondary nucleation leads to the formation of toxic oligomers, and inhibitors of secondary nucleation may serve as starting points for therapeutic developments. Secondary nucleation displays a high degree of structural specificity and may be enhanced by mutations or screening of electrostatic repulsion.

  19. Custom-made Stent Grafts for the Treatment of Pseudoaneurysms after Childhood Coarctation Surgery.

    PubMed

    Lescan, Mario; Hornung, Andreas; Hofbeck, Michael; Schlensak, Christian

    2018-05-17

     Post-coarctation of the aorta (CoA) pseudoaneurysms is a complication of open repair. Thoracic endovascular repair (TEVAR) is feasible but complicated by proximity to the supra-aortic trunks and severe arch angulation.  We describe three cases of post-CoA pseudoaneurysms treated with custom-made Relay stent grafts (Vascutek, Scotland).  Technical and clinical success was achieved in all three cases with no mortality, morbidity, endoleaks, or complications. In all three, pseudoaneurysm sac shrinkage was observed at the follow-ups; in one case, there was complete resolution.  Redo open surgery is challenging because of adhesions of the thoracic cavity and associated morbidity and mortality. TEVAR is less invasive and offers fewer complications. Custom-made modifications overcome difficult anatomies including short landing zones and diameter variability. Georg Thieme Verlag KG Stuttgart · New York.

  20. Iatrogenic Pseudoaneurysm of Superficial Temporal Artery After Surgery for Scaphocephaly: Case Report and Review of Literature.

    PubMed

    Anania, Pasquale; Pacetti, Mattia; Ravegnani, Marcello; Pavanello, Marco; Piatelli, Gianluca; Consales, Alessandro

    2018-03-01

    Iatrogenic pseudoaneurysm of the superficial temporal artery after surgery for craniosynostosis is a complication that has never been described in the pertinent literature. Although reported for other types of surgeries, no case has been described in the pediatric population. We report on a case of pseudoaneurysm of the superficial temporal artery that occurred 9 days after corrective surgery for scaphocephaly. We also describe the management of this complication. Pseudoaneurysm is an exceptional complication in surgery for craniosynostosis, but it should be considered in case of swelling in the temporal region. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Recurrent life-threatening haemoptysis from a bleeding vertebral artery pseudoaneurysm: A diagnostic dilemma.

    PubMed

    Chandran, Arun; Biswas, Shubhabrata; Hartley, James Leon; Nahser, Hans Christean; Lancaster, Jeffrey; Puthuran, Mani

    2016-10-01

    A bleeding vertebral artery pseudoaneurysm is a rare cause of haemoptysis. Pseudoaneurysm can arise due to radionecrosis from previous radiotherapy in the base of skull and neck region and may present with haemoptysis many years later. It is important to be aware of this entity in the work-up of haemoptysis, particularly in patients with previous base of skull and neck radiotherapy. Our patient was successfully treated with endovascular occlusion. © The Author(s) 2016.

  2. Pseudoaneurysm embolization and vasopressin infusion for lower gastrointestinal bleeding due to recurrence of urinary bladder carcinoma.

    PubMed

    Kakizawa, Hideaki; Toyota, Naoyuki; Mita, Koji; Fujimura, Yoshio; Hieda, Masashi; Hirai, Nobuhiko; Tachikake, Toshihiro; Ito, Katsuhide

    2006-05-01

    We report a case that was successfully treated for massive lower gastrointestinal (LGI) bleeding due to a recurrent urinary bladder carcinoma. Treatment consisted of combination therapy including embolization of an inferior gluteal artery (IGA) pseudoaneurysm and low-dose arterial vasopressin infusion via a sigmoid artery (SA). A 57-year-old man presented with life-threatening sudden, massive LGI bleeding due to an obturator lymph node (LN) metastasis from a urinary bladder carcinoma. Computed tomography showed that the LN recurrence had invaded all the way to the sigmoid colon, and there was a pseudoaneurysm with extravasation inside the recurrence. An angiogram revealed a left IGA pseudoaneurysm. We therefore excluded the pseudoaneurysm by embolization with microcoils. Following this treatment the bleeding decreased, but intermittent LGI bleeding continued. Endoscopic examination showed the tumor with a huge ulcer inside the colonic lumen, and continuous oozing was confirmed. A second angiogram showed no recurrence of the IGA pseudoaneurysm and no apparent findings of bleeding. Then a 3F microcatheter was placed in the SA selectively using a coaxial catheter system, and vasopressin was infused at a rate 0.05 U/min for 12 h. Bleeding completely ceased 2 days later. There were no signs of ischemic gastrointestinal complications. Massive LGI bleeding has not recurred in 5 months.

  3. Giant pseudoaneurysm of the left ventricular outflow tract: a rare disease.

    PubMed

    Acioli Pereira, Larissa; Fontes Gontijo, Paula; Alcântara Farran, Jorge; Palandri Chagas, Antonio Carlos; Romano, Edson Renato; Bento de Souza, Luis Carlos

    2013-06-01

    Pseudoaneurysm of the left ventricular outflow tract (LVOT) is a rare disease with high morbidity and mortality, resulting from left ventricular damage due to myocardial infarction, infective endocarditis or surgical trauma. A case of giant pseudoaneurysm of the LVOT, even more rarely reported in the literature, is described. The lesion was detected 12 years after aortic valve replacement for infective endocarditis in a young patient, a former intravenous drug user. As it is an uncommon disease, little is known about its clinical presentation and treatment. Copyright © 2011 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

  4. Emergency ultrasound-guided percutaneous embolization of post-traumatic bleeding hepatic artery pseudoaneurysms.

    PubMed

    Vyas, Sameer; Ahuja, Chirag Kamal; Yadav, Thakur Deen; Khandelwal, Niranjan

    2012-09-01

    Hepatic artery pseudoaneurysm (HAP) is an uncommon but serious complication of blunt trauma abdomen which can be managed by non-surgical interventional methods. We describe the case of a young boy with blunt trauma abdomen having a large hepatic laceration associated with two pseudoaneurysms of the hepatic artery branches. Both these HAPs were successfully managed by percutaneous injection of cyanoacrylate glue under sonographic guidance. A major surgery was thus averted. A brief review of the etiology, diagnosis and management of HAP including the present case is discussed.

  5. Superficial Temporal Artery Pseudoaneurysm: A Conservative Approach in a Critically Ill Patient

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Grasso, Rosario Francesco, E-mail: r.grasso@unicampus.it; Quattrocchi, Carlo Cosimo; Crucitti, Pierfilippo

    A 71-year-old man affected by cardio- and cerebrovascular disease experienced an accidental fall and trauma to the fronto-temporal area of the head. A few weeks later a growing mass appeared on his scalp. A diagnosis of superficial temporal artery pseudoaneurysm was made following CT and color Doppler ultrasound. His clinical condition favoured a conservative approach by ultrasound-guided compression and subsequent surgical resection. A conservative approach should be considered the treatment of choice in critically ill patients affected by superficial temporal artery pseudoaneurysm.

  6. Aortic Branch Artery Pseudoaneurysms Associated with Intramural Hematoma: When and How to Do Endovascular Embolization

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ferro, Carlo; Rossi, Umberto G., E-mail: urossi76@hotmail.com; Seitun, Sara

    To describe when and how to perform endovascular embolization of aortic branch artery pseudoaneurysms associated with type A and type B intramural hematoma (IMH) involving the descending thoracic and abdominal aorta (DeBakey I and III) that increased significantly in size during follow-up. Sixty-one patients (39 men; mean {+-} standard deviation age 66.1 {+-} 11.2 years) with acute IMH undergoing at least two multidetector computed tomographic examinations during follow-up for 12 months or longer were enrolled. Overall, 48 patients (31 men, age 65.9 {+-} 11.5) had type A and type B IMH involving the descending thoracic and abdominal aorta (DeBakey Imore » and III). Among the 48 patients, 26 (54 %; 17 men, aged 64.3 {+-} 11.4 years) had 71 aortic branch artery pseudoaneurysms. Overall, during a mean follow-up of 22.1 {+-} 9.5 months (range 12-42 months), 31 (44 %) pseudoaneurysms disappeared; 22 (31 %) decreased in size; two (3 %) remained stable; and 16 (22 %) increased in size. Among the 16 pseudoaneurysms with increasing size, five of these (three intercostal arteries, one combined intercostobronchial/intercostal arteries, one renal artery), present in five symptomatic patients, had a significant increase in size (thickness >10 mm; width and length >20 mm). These five patients underwent endovascular embolization with coils and/or Amplatzer Vascular Plug. In all patients, complete thrombosis and exclusion of aortic pseudoaneurysm and relief of back pain were achieved. Aortic branch artery pseudoaneurysms associated with type A and type B IMH involving the descending thoracic and abdominal aorta (DeBakey I and III) may be considered relatively benign lesions. However, a small number may grow in size or extend longitudinally with clinical symptoms during follow-up, and in these cases, endovascular embolization can be an effective and safe procedure.« less

  7. Percutaneous Glue Embolization of a Visceral Artery Pseudoaneurysm in a Case of Sickle Cell Anemia

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gulati, Gurpreet S.; Gulati, Manpreet S.; Makharia, Govind

    2006-08-15

    Although aneurysmal complications of sickle cell anemia have been described in the intracranial circulation, visceral artery pseudoaneurysms in this disease entity have not previously been reported in the literature. Conventional treatment of visceral pseudoaneurysms has been surgical ligation or resection of the aneurysm. Transcatheter embolization has emerged as an attractive, minimally invasive alternative to surgery in the treatment of these lesions. In certain situations, however, due to the unfavorable angiographic anatomy precluding safe transcatheter embolization, direct percutaneous glue injection of the pseudoaneurysm sac may be considered to achieve successful occlusion of the sac. The procedure may be rendered safer bymore » simultaneous balloon protection of the parent artery. We describe this novel treatment modality in a case of inferior pancreaticoduodenal artery pseudoaneurysm in a patient with sickle cell anemia. Although a complication in the form of glue reflux into the parent vessel occurred that necessitated surgery, this treatment modality may be used in very selected cases (where conventional endovascular embolization techniques are not applicable) after careful selection of the balloon diameter and appropriate concentration of the glue-lipiodol mixture.« less

  8. On the Secondary Eyewall Formation of Hurricane Edouard (2014)

    NASA Technical Reports Server (NTRS)

    Abarca, Sergio F.; Montgomery, Michael T.; Braun, Scott A.; Dunion, Jason

    2016-01-01

    A first observationally-based estimation of departures from gradient wind balance during secondary eyewall formation is presented. The study is based on the Atlantic Hurricane Edouard (2014). This storm was observed during the National Aeronautics and Space Administrations (NASA) Hurricane and Severe Storm Sentinel (HS3) experiment, a field campaign conducted in collaboration with the National Oceanic and Atmospheric Administration (NOAA). A total of 135 dropsondes are analyzed in two separate time periods: one named the secondary eyewall formation period and the other one referred to as the decaying-double eyewalled storm period. During the secondary eyewall formation period, a time when the storm was observed to have only one eyewall, the diagnosed agradient force has a secondary maxima that coincides with the radial location of the secondary eyewall observed in the second period of study. The maximum spin up tendency of the radial influx of absolute vertical vorticity is within the boundary layer in the region of the eyewall of the storm and the spin up tendency structure elongates radially outward into the secondary region of supergradient wind, where the secondary wind maxima is observed in the second period of study. An analysis of the boundary layer averaged vertical structure of equivalent potential temperature reveals a conditionally unstable environment in the secondary eyewall formation region. These findings support the hypothesis that deep convective activity in this region contributed to spin up of the boundary layer tangential winds and the formation of a secondary eyewall that is observed during the decaying-double eyewalled storm period.

  9. On the secondary eyewall formation of Hurricane Edouard (2014)

    PubMed Central

    Abarca, Sergio F.; Montgomery, Michael T.; Braun, Scott A.; Dunion, Jason

    2018-01-01

    A first observationally-based estimation of departures from gradient wind balance during secondary eyewall formation is presented. The study is based on the Atlantic Hurricane Edouard (2014). This storm was observed during the National Aeronautics and Space Administration’s (NASA) Hurricane and Severe Storm Sentinel (HS3) experiment, a field campaign conducted in collaboration with the National Oceanic and Atmospheric Administration (NOAA). A total of 135 dropsondes are analyzed in two separate time periods: one named the secondary eyewall formation period and the other one referred to as the decaying-double eyewalled storm period. During the secondary eyewall formation period, a time when the storm was observed to have only one eyewall, the diagnosed agradient force has a secondary maxima that coincides with the radial location of the secondary eyewall observed in the second period of study. The maximum spin up tendency of the radial influx of absolute vertical vorticity is within the boundary layer in the region of the eyewall of the storm and the spin up tendency structure elongates radially outward into the secondary region of supergradient wind, where the secondary wind maxima is observed in the second period of study. An analysis of the boundary-layer averaged vertical structure of equivalent potential temperature reveals a conditionally unstable environment in the secondary eyewall formation region. These findings support the hypothesis that deep convective activity in this region contributed to spin up of the boundary layer tangential winds and the formation of a secondary eyewall that is observed during the decaying-double eyewalled storm period. PMID:29651170

  10. On the secondary eyewall formation of Hurricane Edouard (2014).

    PubMed

    Abarca, Sergio F; Montgomery, Michael T; Braun, Scott A; Dunion, Jason

    2016-09-01

    A first observationally-based estimation of departures from gradient wind balance during secondary eyewall formation is presented. The study is based on the Atlantic Hurricane Edouard (2014). This storm was observed during the National Aeronautics and Space Administration's (NASA) Hurricane and Severe Storm Sentinel (HS3) experiment, a field campaign conducted in collaboration with the National Oceanic and Atmospheric Administration (NOAA). A total of 135 dropsondes are analyzed in two separate time periods: one named the secondary eyewall formation period and the other one referred to as the decaying-double eyewalled storm period. During the secondary eyewall formation period, a time when the storm was observed to have only one eyewall, the diagnosed agradient force has a secondary maxima that coincides with the radial location of the secondary eyewall observed in the second period of study. The maximum spin up tendency of the radial influx of absolute vertical vorticity is within the boundary layer in the region of the eyewall of the storm and the spin up tendency structure elongates radially outward into the secondary region of supergradient wind, where the secondary wind maxima is observed in the second period of study. An analysis of the boundary-layer averaged vertical structure of equivalent potential temperature reveals a conditionally unstable environment in the secondary eyewall formation region. These findings support the hypothesis that deep convective activity in this region contributed to spin up of the boundary layer tangential winds and the formation of a secondary eyewall that is observed during the decaying-double eyewalled storm period.

  11. A rare cause of bleeding after laparoscopic sleeve gastrectomy : pseudo-aneurysm of the gastro-omental artery.

    PubMed

    Mege, D; Louis, G; Berthet, B

    2013-01-01

    A serious complication of laparoscopic sleeve gastrectomy (LSG) is bleeding that is primarily located along the staples lines. Bleeding may be due to several causes, including hematomas, trocar sites, or visceral pseudo-aneurysms. We reported here a case of bleeding related to a pseudo-aneurysm of the gastro-omental artery. An LSG was performed on a 43-year-old woman (BMI = 46 kg/m2) without apparent surgical complications. Fifteen days later, she was admitted to the emergency department for hematemesis and symptoms of hemorrhagic shock. Abdominal computed tomography angiography revealed blood in the stomach, without a digestive leak, and active bleeding from a pseudo-aneurysm of the gastro-omental artery. An arterial embolisation was performed with the sandwich technique and angiographic guide wires and the placement of several detachable coils. The patient was discharged two days later. We demonstrated for the first time that post-LSG bleeding may involve a pseudo-aneurysm of the gastro-omental artery.

  12. Internal carotid artery pseudoaneurysm with life-threatening epistaxis as a complication of deep neck space infection.

    PubMed

    da Silva, Paulo Sérgio Lucas; Waisberg, Daniel Reis

    2011-05-01

    Pseudoaneurysm of the cervical internal carotid artery is a very rare, potentially fatal complication of a neck space infection in children associated with high mortality and morbidity. A 3-year-old boy presented with spontaneous massive epistaxis 45 days after a deep neck space infection caused by a peritonsillar abscess. During nasopharyngeal packing, he evolved with cardiac arrest. Intra-arterial angiography was then performed that revealed a large pseudoaneurysm. Endovascular treatment using detachable balloons achieved complete exclusion of the pseudoaneurysm. The child made an uneventful recovery and was discharged with mild left hemiparesis and no deficit of sensory or cognitive functions. Pseudoaneurysms of the internal carotid artery after a deep neck space infection can be associated with delayed and potentially fatal massive epistaxis. Furthermore, a regional (ie, extranasal) blood vessel should be promptly investigated when there are signs of hypovolemic shock. A high level of suspicion and definitive treatment are essential for successful management of these patients.

  13. Minimally invasive image-guided interventional management of hepatic artery pseudoaneurysms.

    PubMed

    Vyas, Sameer; Khandelwal, Niranjan; Gupta, Vivek; Kamal Ahuja, Chirag; Kumar, Ajay; Kalra, Naveen; Kang, Mandeep; Prakash, Mahesh

    2014-01-01

    Hepatic artery pseudoaneurysms (HAPs) are uncommon entities. With the development of interventional techniques, their management has evolved from conventional (surgical) to non-surgical minimally invasive image-guided interventional techniques. Fifteen cases of HAPs who had undergone non-surgical interventional management in our department were reviewed. All patients were comprehensively evaluated for demographic information, morphology of pseudoaneurysm, indication for intervention and means of intervention, approach (endovascular or percutaneous), follow up and complications. Trauma and iatrogenic injury were most common causes of HAPs. Most of the HAPs (9 out of 10 in whom long follow up was available) managed with image-guided interventional techniques had favorable outcome. Minimally invasive image-guided interventional management is the preferred modality for HAPs.

  14. Pseudoaneurysm of the Profunda Femoris Artery following Blunt Trauma Treated by Endovascular Coil Embolization: Review of Two Cases and Relevant Literature

    PubMed Central

    McNerney, Patrick; Kiproff, Paul

    2017-01-01

    Profunda femoris artery (PFA) pseudoaneurysm after blunt trauma without associated femur fracture is a rare occurrence. Most of the reported cases of PFA pseudoaneurysm in the English literature developed after penetrating trauma, surgical procedures, and femur fractures. We present two such cases following blunt trauma and without any associated long bone injury. After initial imaging failed to show any long bone fracture, CT angiography confirmed pseudoaneurysm of the branch of the PFA. Both patients were then treated with emergent coil embolization of the bleeding vessel. Pseudoaneurysms typically present late and signs of persistent hip pain, thigh swelling, presence of a pulsatile mass, and even unexplained anemia all may suggest the diagnosis. Recognition of PFA pseudoaneurysm requires high index of suspicion and is often difficult to diagnose clinically because of its location. PMID:28246563

  15. Stent-Graft Repair of a Large Cervical Internal Carotid Artery Pseudoaneurysm Causing Dysphagia

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gupta, Vivek, E-mail: drvivekgupta.pgi@gmail.com; Niranjan, Khandelwal; Rawat, Lokesh

    2009-05-15

    Pseudoaneurysms of the cervical internal carotid artery (ICA) are rare and most frequently result from trauma, infection, or sometimes spontaneously. They have the potential to cause life-threatening hemorrhage; thus, their immediate management is necessary. Endovascular treatment by stent graft placement in the affected artery appears to be a safe and effective treatment option. We present a case of a child who presented with neck swelling and dysphagia caused by a ruptured cervical ICA pseudoaneurysm which was managed by stent graft placement.

  16. Pseudoaneurysm of the superior lateral genicular artery: case report of a rare complication after total knee arthroplasty.

    PubMed

    Saini, Pramod; Meena, Sanjay; Malhotra, Rajesh; Gamanagatti, Shivanand; Kumar, Vijay; Jain, Vaibhav

    2013-01-01

    Pseudoaneurysm of superior lateral genicular artery following total knee arthroplasty is a rare complication and has been reported following lateral release performed for eversion of patella in a knee with tight lateral structures. This report describes a case of pseudo aneurysm of superior lateral geniculate artery that developed after primary Total knee arthroplasty for a stiff knee in a 68 year old patient. Patient presented with pain and rapidly increasing swelling in early post operative period. Diagnosis was made on duplex ultrasound and confirmed by angiography. Angiographic coil embolisation of the pseudoaneurysm was performed. Since no lateral release was performed in this case, the probable mechanism was shear injury to the vessel. Pseudoaneurysm of superior lateral genicular artery can occur in absence of lateral release by shear injury to an atherosclerotic vessel. Angiographic coil embolisation appears to be the best method for treating such post arthroplasty pseudoaneurysm because of less chance of infection, non interference with rehabilitation and diagnosis and treatment during same procedure.

  17. Ruptured Pseudoaneurysm of the Lateral Plantar Artery After Tibiotalocalcaneal Fusion With Retrograde Nail-A Rare Complication.

    PubMed

    Sundararajan, Silvampatti Ramaswamy; Rajagopalakrishnan, Ramakanth; Rajasekaran, Shanmuganathan

    We report a rare presentation of a ruptured pseudoaneurysm of the lateral plantar artery following tibiotalocalcaneal fusion with a retrograde nail at 1 month after the index surgery. Although case reports of pseudoaneurysms of larger arteries such as the anterior tibial artery and posterior tibial artery after ankle surgery (e.g., ankle arthroscopy, implant removal, Ilizarov application) have been reported, we report a rare complication of a pseudoaneurysm of the lateral plantar artery. We discuss the anatomic considerations of the lateral plantar artery in the foot and the entry point of the retrograde nail to avoid this unusual complication. Copyright © 2017 The American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  18. Covered Stent and Coils Embolization of a Pulmonary Artery Pseudoaneurysm After Gunshot Wound

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Huet, Nicolas, E-mail: nhuet@chu-grenoble.fr; Rodiere, Mathieu, E-mail: mrodiere@chu-grenoble.fr; Badet, Michel, E-mail: michel.badet@ch-chambery.fr

    We report the first case of endovascular covered stent implantation for the treatment of a large pulmonary artery pseudoaneurysm (PAPA) following a right thoracic gunshot wound. After resuscitation and hemodynamic stabilization, a CT angiography was performed to analyze the neck size of the PAPA and its position relative to the branches of the parent artery. Covered stent implantation with additional coil embolization was successfully performed. At the 4-year follow-up, the stents remained patent and there was neither pseudoaneurysm recurrence nor treatment-related complication.

  19. Compression of the right coronary artery by an aortic pseudoaneurysm after infective endocarditis: an unusual case of myocardial ischemia.

    PubMed

    Lacalzada-Almeida, Juan; De la Rosa-Hernández, Alejandro; Izquierdo-Gómez, María Manuela; García-Niebla, Javier; Hernández-Betancor, Iván; Bonilla-Arjona, Juan Alfonso; Barragán-Acea, Antonio; Laynez-Cerdeña, Ignacio

    2018-01-01

    A 61-year-old male with a prosthetic St Jude aortic valve size 24 presented with heart failure symptoms and minimal-effort angina. Eleven months earlier, the patient had undergone cardiac surgery because of an aortic root dilatation and bicuspid aortic valve with severe regurgitation secondary to infectious endocarditis by Coxiela burnetii and coronary artery disease in the left circumflex coronary artery. Then, a prosthesis valve and a saphenous bypass graft to the left circumflex coronary artery were placed. The patient was admitted to the Cardiology Department of Hospital Universitario de Canarias, Tenerife, Spain and a transthoracic echocardiography was performed that showed severe paraprosthetic aortic regurgitation and an aortic pseudoaneurysm. The 64-slice multidetector computed tomography confirmed the pseudoaneurysm, originating from the right sinus of Valsalva, with a compression of the native right coronary artery and a normal saphenous bypass graft. On the basis of these findings, we performed surgical treatment with a favorable postoperative evolution. In our case, results from complementary cardiac imaging techniques were crucial for patient management. The multidetector computed tomography allowed for a confident diagnosis of an unusual mechanism of coronary ischemia.

  20. Diagnosis and Management of Transplanted Kidney Extrarenal Pseudoaneurysms: A Series of Four Cases and a Review of the Literature

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Fananapazir, Ghaneh, E-mail: fananapazir@ucdavis.edu; Hannsun, Gemmy; Wright, Luke A.

    Extrarenal pseudoaneurysms of transplanted kidneys are very rare but can have devastating consequences. In the past, these extrarenal pseudoaneurysms have often led to graft loss as well as significant morbidity and mortality. The role of advanced diagnostic imaging studies and of modern radiologic interventional management has not been studied. In this case series, we present four cases of extrarenal pseudoaneurysms of transplanted kidneys, describe the clinical scenarios and imaging that led to the angiographic diagnosis, and discuss the various endovascular and surgical approaches to management.

  1. Ultrasound-Guided Thrombin Injection Is a Safe and Effective Treatment for Femoral Artery Pseudoaneurysm in the Morbidly Obese.

    PubMed

    Yoo, Taehwan; Starr, Jean E; Go, Michael R; Vaccaro, Patrick S; Satiani, Bhagwan; Haurani, Mounir J

    2017-08-01

    Ultrasound-guided thrombin injection (UGTI) is a well-established practice for the treatment of femoral artery pseudoaneurysm. This procedure is highly successful but dependent on appropriate pseudoaneurysm anatomy and adequate ultrasound visualization. Morbid obesity can present a significant technical challenge due to increased groin adiposity, resulting in poor visualization of critical structures needed to safely perform the procedure. We aim to evaluate the safety and efficacy of UGTI to treat femoral artery pseudoaneurysm in the morbidly obese. This is a retrospective cohort study in which all patients who underwent UGTI at The Ohio State University Ross Heart Hospital from 2009 to 2014 were analyzed for patient characteristics and stratified by body mass index (BMI). Patients with BMI ≥ 35 were considered morbidly obese and were compared to patients with a BMI < 35. Outcome was failed treatment resulting in residual pseudoaneurysm. Our cohort consisted of 54 patients who underwent thrombin injection. There were 41 nonmorbidly obese and 13 morbidly obese patients. Mean age was 64.5 years. The cohort was 44.4% male. There were 6 failures, of which 1 underwent successful repeat injection and 5 underwent open surgical repair. There was no statistically significant difference in failure between nonmorbidly obese and morbidly obese patients (9.8% vs 15.4%, P = .45). There were no embolic/thrombotic complications. Ultrasound-guided thrombin injection is a safe and effective therapy in the morbidly obese for the treatment of femoral artery pseudoaneurysm. In the hands of experienced sonographers and surgeons with adequate visualization of the pseudoaneurysm sac, UGTI should remain a standard therapy in the morbidly obese.

  2. Traumatic cervical internal carotid artery pseudoaneurysm in a child refractory to initial endovascular treatment: case report and technical considerations.

    PubMed

    Wang, Arthur; Santarelli, Justin G; Stiefel, Michael F

    2016-12-01

    Optimal management of extracranial carotid artery dissections (eCAD) in pediatric patients is not well documented, and endovascular interventions are rarely reported. A 10-year-old girl sustained multiple systemic injuries in a motor vehicle accident, including an eCAD with pseudoaneurysm. She initially failed both aspirin and endovascular stenting with progressive enlargement of a traumatic cervical carotid pseudoaneurysm and stenosis. Second-stage endovascular stent placement with coiling resulted in successful occlusion of the pseudoaneurysm. At 30-month imaging follow-up, the parent vessel remained patent with no evidence of the pseudoaneurysm. In the setting of poly-trauma, management of eCAD can be complex especially in the pediatric population. There is little data on the endovascular treatment of eCAD in children. Failed endovascular therapies are extremely rare. Our report supports surveillance imaging as repeat endovascular treatment may be necessary.

  3. Pseudoaneurysm of the superior lateral genicular artery: case report of a rare complication after total knee arthroplasty

    PubMed Central

    2013-01-01

    Background Pseudoaneurysm of superior lateral genicular artery following total knee arthroplasty is a rare complication and has been reported following lateral release performed for eversion of patella in a knee with tight lateral structures. Case presentation This report describes a case of pseudo aneurysm of superior lateral geniculate artery that developed after primary Total knee arthroplasty for a stiff knee in a 68 year old patient. Patient presented with pain and rapidly increasing swelling in early post operative period. Diagnosis was made on duplex ultrasound and confirmed by angiography. Angiographic coil embolisation of the pseudoaneurysm was performed. Since no lateral release was performed in this case, the probable mechanism was shear injury to the vessel. Conclusion Pseudoaneurysm of superior lateral genicular artery can occur in absence of lateral release by shear injury to an atherosclerotic vessel. Angiographic coil embolisation appears to be the best method for treating such post arthroplasty pseudoaneurysm because of less chance of infection, non interference with rehabilitation and diagnosis and treatment during same procedure. PMID:23687974

  4. Stent-Graft Placement with Early Debridement and Antibiotic Treatment for Femoral Pseudoaneurysms in Intravenous Drug Addicts

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Fu, Qining, E-mail: cqmufqn@163.com; Meng, Xiyun, E-mail: 383274177@qq.com; Li, Fenghe, E-mail: lfh-cqmu@gmail.com

    PurposeExplore the application of endovascular covered stent-graft (SG) placement in femoral pseudoaneurysms in intravenous drug addicts.Materials and MethodsWe evaluated a consecutive series of pseudoaneurysm in intravenous drug addicts treated with SGs from August 2010 to December 2013.Results15 patients with 16 arterial pseudoaneurysms were enrolled in this study. All were males with a mean age of 36.9 years. Hemorrhage was the most common reason (93.8 %) for seeking medical care, and 3 of these patients were in hemorrhagic shock at admission. All patients received broad-spectrum antibiotics, and debridement and drainage were implemented after SG placement. 7 of the 13 cases which had microbiologicmore » results showed mixed infections, while gram-negative bacteria were the major pathogens. Except for 2 patients, who were lost to follow-up, two new pseudoaneurysms formed due to delayed debridement, and one stent thrombosis occurred, none of the remaining cases had SG infection or developed claudication.ConclusionsSG placement controls massive hemorrhage rapidly, gives enough time for subsequent treatment for pseudoaneurysms due to intravenous drug abuse, and reduces the incidence of postoperative claudication. With appropriate broad-spectrum antibiotics and early debridement, the incidence of SG infection is relatively low. It is an effective alternative especially as temporary bridge measure for critical patients. However, the high cost, uncertain long-term prospects, high demand for medical adherence, and the risk of using the conduits for re-puncture call for a cautious selection of patients. More evidence is required for the application of this treatment.« less

  5. Hybrid treatment of a huge complex aortic pseudo-aneurysm subsequent to a coarctation.

    PubMed

    Rizza, Antonio; Barletta, Valentina; Palmieri, Cataldo; Berti, Sergio

    2017-07-01

    Endovascular treatment of pseudo-aneurysms subsequent to a pre-existing aortic coarctation is becoming a well-accepted technical solution especially in patients presenting anatomical challenges involving the aortic arch. We report the case of a 65-year-old woman with a huge pseudo-aneurysm of the descending thoracic aorta. Diagnostic imaging assessment documented also the presence of an aneurysmatic aberrant right subclavian artery. Due to patient's anatomical arterial condition, we decided to treat the aneurysm applying a hybrid approach. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  6. Respiratory distress after surgery of RVOT pathologies: a word of caution on pseudoaneurysm development.

    PubMed

    Antal, A Donmez; Cikirikcioglu, M; Myers, P O; Didier, D; Kalangos, A

    2010-09-01

    Pseudoaneurysm of the right ventricle outflow tract (RVOT) is a rare complication in pediatric cardiac surgery. We report a patient who developed a right ventricular pseudoaneurysm 8 months after RVOT enlargement using a pericardial patch for infundibular pulmonary stenosis. Our patient was born with severe pulmonary valvular stenosis and treated with percutaneous balloon valvotomy in the neonatal period. Six months later, she developed infundibular pulmonary stenosis, which required surgical resection of right ventricle infundibular trabeculations and bovine pericardial patch enlargement. The postoperative period was normal. She was readmitted to hospital 5 months later complaining of wheezing, coughing and shortness of breath. Echocardiography showed a huge aneurysmal dilatation of the outflow patch in connection with the right ventricular cavity. The patient underwent resection of the pseudoaneurysm and former patch, followed by interposition of a bovine jugular vein conduit between the RVOT and pulmonary bifurcation. The early postoperative period was uncomplicated. On echocardiography, no significant residual gradient was measured through the conduit and there was no insufficiency of the valve. RVOT reconstruction with patch enlargement, homograft or conduit implantation can be the origin of pseudoaneurysms. Although their incidence is rare, they are often asymptomatic before becoming quite large and causing compression symptoms as in our patient with respiratory complaints due to airway compression. It is important to follow up these patients closely, especially in the first year after surgery since most aneurysms develop within 6 months of surgery. Georg Thieme Verlag KG Stuttgart, New York.

  7. Pseudoaneurysm of the saphenous vein graft related to artificial rubber pericardium--a case report.

    PubMed

    Harada, Tomohiro; Ida, Takao; Koyanagi, Toshiya; Kasahara, Katsuhiko; Naganuma, Fumio; Hosoda, Saichi

    2002-01-01

    Pseudoaneurysm is an unusual complication of coronary artery bypass grafting. Such aneurysms are caused by technical surgical failures, or inflammation of the sternum and mediastinum following sternotomy observed as an early or mid-term complication of cardiac surgery. This case was an 80-year-old man with a piece of artificial rubber pericardium used for complete closure of the pericardium. A large pseudoaneurysm developed in the body of the saphenous vein graft 15 years after surgery. The old rubber synthetic pericardium was severely degenerative, which induced inflammation and disrupted the saphenous vein graft.

  8. Modality-specific occult intrarenal pseudoaneurysm in a renal allograft and the legacy of catheter angiography.

    PubMed

    Rastogi, Neeraj; Williams, Gethin; Alencar, Herlen

    2013-11-01

    A 69-year-old man with history of end-stage-renal disease (ESRD) underwent successful kidney transplantation from a cadaveric donor in November 2011. However, posttransplant recovery was complicated by delayed graft function and recurrent gross hematuria. Serial Doppler ultrasound (US) of the renal allograft demonstrated a pseudoaneurysm with interval increase in size. However, it could not be visualized with other modalities, including an initial angiogram (postoperative day 49) and a second angiogram (postoperative day 68), followed by surgical exploration (postoperative day 71), which demonstrated complete intra-aneurysmal thrombosis on intraoperative Doppler US. Unfortunately, the patient's hematuria continued and a repeat Doppler US 48 hours later demonstrated a persistent pseudoaneurysm. Therefore, on postoperative day 75, we performed targeted percutaneous intra-aneurysmal thrombin injection under dual image guidance, which showed complete intra-aneurysmal thrombosis on intraprocedural Doppler US. Hematuria recurred the next day. A third angiogram (postoperative day 77) finally illuminated the hidden pseudoaneurysm occult on the first and second angiographic studies (sensitivity [index case] 33%) and surgery. This allowed for successful coil embolization of a subsegmental feeding branch with an excellent outcome. We support a more aggressive management with serial angiography and embolization of the intrarenal symptomatic pseudoaneurysm rather than surgery in renal allograft recipients, with the benefits outweighing the risks. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. Delayed postpartum haemorrhage secondary to a ruptured uterine artery pseudo-aneurysm, successfully treated by transarterial embolisation

    PubMed Central

    Moatti, Zoe; Nisner, Tamar; Saini, Ashish; Karoshi, Mahantesh

    2011-01-01

    A 29-year-old woman (gravida 1, para 1) had an uneventful first pregnancy and a delivery by emergency caesarean section at term. The caesarean section was complicated by a massive obstetric haemorrhage of 5000 ml. After closure, an immediate re-laparotomy was indicated due to heavy vaginal bleeding. The site of bleeding was identified as an extension of the uterine incision, and was sutured. She was stabilised by transfusion of blood and blood products in the intensive therapy unit, and discharged 5 days later. The patient was re-admitted 6 weeks later with brisk, painless vaginal bleeding, passing large clots from a well-contracted uterus. Her haemoglobin decreased from 11.8 to 7.8 g/dl overnight. In view of her history, an urgent CT angiogram was performed, which revealed the presence of a pseudo-aneurysm arising from the left uterine artery. This was successfully occluded by transarterial embolisation, obviating the need for further surgical exploration. PMID:22674937

  10. Delayed postpartum haemorrhage secondary to a ruptured uterine artery pseudo-aneurysm, successfully treated by transarterial embolisation.

    PubMed

    Moatti, Zoe; Nisner, Tamar; Saini, Ashish; Karoshi, Mahantesh

    2011-12-01

    A 29-year-old woman (gravida 1, para 1) had an uneventful first pregnancy and a delivery by emergency caesarean section at term. The caesarean section was complicated by a massive obstetric haemorrhage of 5000 ml. After closure, an immediate re-laparotomy was indicated due to heavy vaginal bleeding. The site of bleeding was identified as an extension of the uterine incision, and was sutured. She was stabilised by transfusion of blood and blood products in the intensive therapy unit, and discharged 5 days later. The patient was re-admitted 6 weeks later with brisk, painless vaginal bleeding, passing large clots from a well-contracted uterus. Her haemoglobin decreased from 11.8 to 7.8 g/dl overnight. In view of her history, an urgent CT angiogram was performed, which revealed the presence of a pseudo-aneurysm arising from the left uterine artery. This was successfully occluded by transarterial embolisation, obviating the need for further surgical exploration.

  11. Covered Stent-Graft Treatment of Traumatic Internal Carotid Artery Pseudoaneurysms: A Review

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Maras, Dimitrios; Lioupis, Christos; Magoufis, George

    Objective. To review the literature concerning the management with placement of covered stent-grafts of traumatic pseudoaneurysms of the extracranial internal carotid artery (ICA) resulting from penetrating craniocervical injuries or skull base fractures. Method. We have reviewed, from the Medline database, all the published cases in the English literature since 1990 and we have added a new case. Results. We identified 20 patients with traumatic extracranial ICA pseudoaneurysms due to penetrating craniocervical injuries or skull base fractures who had been treated with covered stent-graft implantation. Many discrepancies have been ascertained regarding the anticoagulation therapy. In 3 patients the ICA was totallymore » occluded in the follow-up period, giving an overall occlusion rate 15%. No serious complication was reported as a result of the endovascular procedure. Conclusion. Preliminary results suggest that placement of stent-grafts is a safe and effective method of treating ICA traumatic pseudoaneurysms resulting from penetrating craniocervical injuries or skull base fractures. The immediate results are satisfactory when the procedure takes place with appropriate anticoagulation therapy. The periprocedural morbidity and mortality and the early patency are also acceptable. A surveillance program with appropriate interventions to manage restenosis may improve the long-term patency.« less

  12. Stent-Graft Placement for Femoral Artery Pseudoaneurysm in a Patient with Idiopathic Multiple Arterial Aneurysmal Disease

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Koo, Bon Kwon; Choi, Donghoon; Kwon, Kihwan

    2002-12-15

    A 34-year-old man presenting with a left inguinal mass was diagnosed as having idiopathic multiple aneurysmal disease and pseudoaneurysm of a left superficial femoral artery. A stent-graft was successfully deployed percutaneously at the left superficial femoral artery pseudoaneurysm. Less invasive treatment should be used to avoid vascular complications in patients with idiopathic multiple aneurysmal disease, especially in those who have a progressive course or a history of prior complications after surgical repair.

  13. [Brachial artery pseudoaneurysm: a rare but serious complication in hemodialysis patients with arteriovenous fistula].

    PubMed

    Mancini, Andrea; Castriotta, Giuseppe; Angelini, Pernina; Bozzi, Michele; Giancaspro, Vincenzo; La Raia, Elvira; Nisi, Maria Teresa; Proscia, Anna Rita; Tarantino, Giuseppe; Vitale, Ottavia; Cuzzola, Cristoforo

    2017-06-01

    A pseudoaneurysm or false aneurysm of the brachial artery is an uncommon occurrence in patients receiving hemodialysis with arteriovenous fistula (AVF). We describe the case of a 76-year-old woman presenting with a large, tender, pulsatile mass in the right antecubital region 10 cm from the AVF. B-mode ultrasound examination revealed a saccular hematoma. Color doppler showed a recirculation movement of blood, creating a two colors image called "Korean flag". The patient was transferred to the surgical unit where she first underwent ultrasound-guided compression and then surgical repair of the pseudoaneurysm. Two weeks after surgery the AVF was used again as an access for hemodialysis. Differentiating between a false and a true aneurysm based on ultrasound is not always straightforward. Doppler ultrasound findings can be decisive for the early diagnosis of a pseudoaneurysm to ensure proper treatment planning given the dangerous complications of ruptures. Treatment options include: compression, percutaneous thrombin injection, endovascular exclusion with covered stents, aneurysmectomy and surgical repair. Copyright by Società Italiana di Nefrologia SIN, Rome, Italy.

  14. Endovascular treatment of visceral artery aneurysms and pseudoaneurysms with stent-graft: Analysis of immediate and long-term results.

    PubMed

    Cappucci, Matteo; Zarco, Federico; Orgera, Gianluigi; López-Rueda, Antonio; Moreno, Javier; Laurino, Florindo; Barnes, Daniel; Tipaldi, Marcello Andrea; Gomez, Fernando; Macho Fernandez, Juan; Rossi, Michele

    2017-05-01

    The aim of this study is to analyze the safety and efficacy of stent-graft endovascular treatment for visceral artery aneurysms and pseudoaneurysms. Multicentric retrospective series of patients with visceral aneurysms and pseudoaneurysms treated by means of stent graft. The following variables were analyzed: Age, sex, type of lesion (aneurysms/pseudoaneurysms), localization, rate of success, intraprocedural and long term complication rate (SIR classification). Follow-up was performed under clinical and radiological assessment. Twenty-five patients (16 men), with a mean age of 59 (range 27-79), were treated. The indication was aneurysm in 19 patients and pseudoaneurysms in 6. The localizations were: splenic artery (12), hepatic artery (5), renal artery (4), celiac trunk (3) and gastroduodenal artery (1). Successful treatment rate was 96% (24/25 patients). Intraprocedural complication rate was 12% (4% major; 8% minor). Complete occlusion was demonstrated during follow up (mean 33 months, range 6-72) in the 24 patients with technical success. Two stent migrations (2/24; 8%) and 4stent thrombosis (4/24; 16%) were detected. Mortality rate was 0%. In our study, stent-graft endovascular treatment of visceral aneurysmns and pseudoaneurysms has demonstrated to be safe and is effective in the long-term in both elective and emergent cases, with a high rate of successful treatment and a low complication rate. Copyright © 2017 AEC. Publicado por Elsevier España, S.L.U. All rights reserved.

  15. A case of gastrointestinal bleeding due to right hepatic artery pseudoaneurysm following total remnant pancreatectomy: A case report.

    PubMed

    Fujio, Atsushi; Usuda, Masahiro; Ozawa, Yohei; Kamiya, Kurodo; Nakamura, Takanobu; Teshima, Jin; Murakami, Kazushige; Suzuki, On; Miyata, Go; Mochizuki, Izumi

    2017-01-01

    Pseudoaneurysm is a serious complication after pancreatic surgery, which mainly depends on the presence of a preceding pancreatic fistula. Postpancreatectomy hemorrhage following total pancreatectomy is a rare complication due to the absence of a pancreatic fistula. Here we report an unusual case of massive gastrointestinal bleeding due to right hepatic artery (RHA) pseudoaneurysm following total remnant pancreatectomy. A 75-year-old man was diagnosed with intraductal papillary mucinous carcinoma recurrence following distal pancreatectomy and underwent total remnant pancreatectomy. After discharge, he was readmitted to our hospital with melena because of the diagnosis of gastrointestinal bleeding. Gastrointestinal endoscopy was performed to detect the origin of bleeding, but an obvious bleeding point could not be detected. Abdominal computed tomography demonstrated an expansive growth, which indicated RHA pseudoaneurysm. Emergency angiography revealed gastrointestinal bleeding into the jejunum from the ruptured RHA pseudoaneurysm. Transcatheter arterial embolization was performed; subsequently, bleeding was successfully stopped for a short duration. Because of improvements in his general condition, the patient was discharged. To date, very few cases have described postpancreatectomy hemorrhage following total remnant pancreatectomy. We suspect that the aneurysm ruptured into the jejunum, possibly because of the scarring and inflammation associated with his two complex surgeries. Pseudoaneurysm should be considered when the fragility of blood vessels is suspected, despite no history of anastomotic leak and intra-abdominal abscess. Our case also highlighted that detecting gastrointestinal bleeding is necessary to recognize sentinel bleeding if the origin of bleeding is undetectable.

  16. Transcriptional control of secondary growth and wood formation.

    Treesearch

    Juan Du; Andrew Groover

    2010-01-01

    Secondary growth and wood formation are products of the vascular cambium, a lateral meristem. Although the mechanisms have only recently begun to be uncovered, transcriptional regulation appears increasingly central to the regulation of secondary growth. The importance of transcriptional regulation is illustrated by the correlation of expression of specific classes of...

  17. Endovascular approach to treat ascending aortic pseudoaneurysm in a patient with previous CABG and very high surgical risk.

    PubMed

    Zago, Alexandre C; Saadi, Eduardo K; Zago, Alcides J

    2011-10-01

    Pseudoaneurysm of the ascending aorta is an uncommon pathology and a challenge in high-risk patients who undergo conventional surgery because of high operative morbidity and mortality. Endovascular exclusion of an aortic pseudoaneurysm using an endoprosthesis is a less invasive approach, but few such cases have been reported. Moreover, the use of this approach poses unique therapeutic challenges because there is no specific endoprosthesis for ascending aortic repair, particularly to treat patients with previous coronary artery bypass graft (CABG). We describe the case of a 74-year-old patient who had undergone CABG and later presented with an iatrogenic ascending aortic pseudoaneurysm that occurred during an angiography. This patient was at very high risk for surgical treatment and, therefore, an endovascular approach was adopted: percutaneous coronary intervention for the left main coronary artery, left anterior descending and left circumflex native coronary arteries followed by endovascular endoprosthesis deployment in the ascending aorta to exclude the pseudoaneurysm. Both procedures were successfully performed, and the patient was discharged without complications 4 days later. At 5 months' clinical follow-up, his clinical condition was good and he had no complications. Copyright © 2011 Wiley-Liss, Inc.

  18. Pseudoaneurysms occurring as a result of fractures giving rise to the appearance of pseudotumors: a short series.

    PubMed

    Farquharson, Finn; Haroon, Athar; Fleet, Mustafa

    2007-01-01

    Pseudoaneurysms are focal enlargements of the vascular lumen due to partial or complete disruption of the arterial wall. These are an uncommon complication of fractures. The presence of a pseudoaneurysm adjacent to a fracture fragment can cause a pressure effect. This pressure not only impairs fracture healing but sometimes can erode the adjacent bone, producing the appearance of a pseudotumor. We present two such cases and discuss the management of these patients.

  19. Splenic artery pseudoaneurysm due to seatbelt injury in a glucose-6-phosphate dehydrogenase-deficient adult.

    PubMed

    Lau, Yu Zhen; Lau, Yuk Fai; Lai, Kang Yiu; Lau, Chu Pak

    2013-11-01

    A 23-year-old man presented with abdominal pain after suffering blunt trauma caused by a seatbelt injury. His low platelet count of 137 × 10(9)/L was initially attributed to trauma and his underlying hypersplenism due to glucose-6-phosphate dehydrogenase (G6PD) deficiency. Despite conservative management, his platelet count remained persistently reduced even after his haemoglobin and clotting abnormalities were stabilised. After a week, follow-up imaging revealed an incidental finding of a pseudoaneurysm (measuring 9 mm × 8 mm × 10 mm) adjacent to a splenic laceration. The pseudoaneurysm was successfully closed via transcatheter glue embolisation; 20% of the spleen was also embolised. A week later, the platelet count normalised, and the patient was subsequently discharged. This case highlights the pitfalls in the detection of a delayed occurrence of splenic artery pseudoaneurysm after blunt injury via routine delayed phase computed tomography. While splenomegaly in G6PD may be a predisposing factor for injury, a low platelet count should arouse suspicion of internal haemorrhage rather than hypersplenism.

  20. Tuberculous abdominal aortic pseudoaneurysm with renal and vertebral tuberculosis: a case and literature review.

    PubMed

    Zhang, Chao; Chen, Bing; Gu, Yongquan; Luo, Tao; Yang, Shengjia; Liang, Weitao; Wang, Zhonggao

    2014-09-12

    Tuberculous pseudoaneurysm of the aorta is rare and exposes patients to a very high risk of unpredictable rupture. To our best knowledge, only 32 cases have been reported related to all arterial systems from 1993 to 2013 in the literature. We report a 44-year-old male who presented with an aortic pseudoaneurysm and tuberculosis of the kidney and vertebrae. He underwent endovascular repair and antibiotic therapy for tuberculosis, combined with a bare stent implanted to seal endoleaks after endograft stenting. The postoperative course was uneventful and the patient recovered and lived well afterwards. Epidemiology, pathogenesis, presentation, management, and mortality of this entity were reviewed and discussed.

  1. Ruptured petrous carotid pseudoaneurysm due to tuberculous otitis: endovascular treatment.

    PubMed

    Yagci, A B; Ardiç, F N; Oran, I; Bir, F; Karabulut, N

    2006-03-15

    We report the imaging findings and endovascular treatment in an unusual case of petrous internal carotid artery pseudoaneurysm due to primary tuberculous otitis. The aneurysm was recognized and ruptured during a surgical intervention for otitis. Successful endovascular treatment of the aneurysm was performed by occlusion of the parent vessel using detachable balloon and coils.

  2. Emergent Embolization of a Very Late Detected Pseudoaneurysm at a Lower Pole Subsegmental Artery of the Kidney after Clampless Laparoscopic Partial Nephrectomy

    PubMed Central

    Chiancone, Francesco; Fedelini, Maurizio; Pucci, Luigi; Di Lorenzo, Domenico; Meccariello, Clemente; Fedelini, Paolo

    2017-01-01

    Renal artery pseudoaneurysm is a rare but life-threatening condition. Its incidence is higher after minimally invasive partial nephrectomy (PN) than after the open approach. We reported a case of a renal artery pseudoaneurysm occurred about four months after a clampless laparoscopic PN. A 49-year-old female underwent a clampless laparoscopic PN for a right renal tumor with high surgical complexity. The patient experienced an intraoperative blood loss from renal bed and the surgeons performed a deep medullary absorbable suture. Three months after surgery the patient underwent a renal ultrasonography with good results. The patient came to our emergency department 115 days after surgery with a hypovolemic shock stage 3. Her CT scan showed a pseudoaneurysm of a lower pole vessel of the right kidney. She underwent a superselective embolization of the segmental renal artery. The surgical complexity of the tumor, the anatomical relationships with the renal sinus and the deep medullary suture could be responsible for the development of the pseudoaneurysm. The authors presented an unusual case of a very late detected pseudoaneurysm of a renal vessel, suggesting that all very complex renal tumors removed with a minimally invasive technique should be followed up closely at least during the first six-months in order to early detect this major complication. PMID:28785196

  3. Left ventricle pseudoaneurysm in a transplanted heart from a car crash victim donor.

    PubMed

    Urbanowicz, Tomasz; Katarzyński, Sławomir; Puślecki, Mateusz; Budniak, Wiktor; Araszkiewicz, Aleksander; Łanocha, Magdalena; Pyda, Małgorzata; Straburzyńska-Migaj, Ewa; Jemielity, Marek

    2014-06-26

    Pseudoaneurysm is a very rare and unusual form of myocardial rupture, with complications such as chest trauma, inflammation, acute myocardial infarction, and infection. Although this rare complication has already been reported, it has never been found in a transplanted patient. We present the case of a 54-year-old women waiting on the urgent list who underwent heart transplantation. The donor of the organ died in a car accident. Although preoperative echocardiography had not revealed any signs of heart injury, a superficial small (3 × 3 mm hematoma) was detected on harvesting. After implantation, intraoperative echocardiography was satisfactory, with no signs of wall motion disturbances, and left ventricle ejection fraction was estimated at 50%. The postoperative period was uneventful. Three weeks after surgery, a left ventricle pseudoaneurysm was found on routine MRI. The aneurysm wall consisted of only an epicardial layer. There was an 8-mm-wide gap in the myocardial wall next to the endocardium and with the width of 4 mm beneath the epicardium. On repeated MRI performed 3 months thereafter, the pseudoaneurysm was filled by thrombus. The presented case illustrates the necessity of careful inspection of the organ reported for transplantation from a donor who died from high-speed motor vehicle crash injuries. Additional diagnostic steps like MRI imaging are obligatory after transplantation, especially when the organ was harvested from a motor vehicle crash victim.

  4. Formation of halogen-induced secondary organic aerosol (XOA)

    NASA Astrophysics Data System (ADS)

    Kamilli, Katharina; Ofner, Johannes; Zetzsch, Cornelius; Held, Andreas

    2013-04-01

    Reactive halogen species (RHS) are very important due to their potential of stratospheric ozone depletion and surface ozone destruction. RHS seem to interact with precursors of secondary organic aerosol (SOA) similarly to common atmospheric oxidants like OH radicals and ozone. The potential interaction of RHS with preformed SOA has recently been studied (Ofner et al., 2012). Although aerosol formation from reaction of RHS with typical SOA precursors was previously studied (e.g. Cai et al., 2006), no data are available on bromine-induced aerosol formation from organic precursors yet. An aerosol smog-chamber was used to examine the halogen-induced secondary organic aerosol (XOA) formation under atmospheric conditions using simulated sunlight. With a concentration of 10 ppb for the organic precursor, 2 ppb for molecular chlorine, and 10 ppb for molecular bromine, the experimental setup is close to ambient conditions. By combined measurements of the aerosol size distribution, ozone and NOx mixing ratios, as well as the decay of the organic precursor, aerosol yields and aerosol growth rates were determined. The decay of the organic precursor was analyzed by capillary gas chromatography coupled with flame-ionization detection (GC-FID) and the aerosol size distribution was measured using a Scanning Mobility Particle Sizer (SMPS). Additionally, with the decay rate of the precursor and the calculated photolysis rates of molecular halogen species, based on the well-known spectrum of the solar simulator, mechanistic details on the XOA formation pathways can be determined. We observed XOA formation even at very low precursor and RHS concentrations with a diameter mode at 10-20 nm and a number concentration up to 1000000 particles cm-3. While the XOA formation from chlorine is very rapid, the interaction of bromine with the organic precursors is about five times slower. The aerosol yield reached maximum values of 0.01 for the reaction of chlorine with α-pinene and 0.0004 for

  5. Organosulfate Formation in Biogenic Secondary Organic Aerosol

    EPA Science Inventory

    Organosulfates of isoprene, α-pinene, and β-pinene have recently been identified in both laboratory-generated and ambient secondary organic aerosol (SOA). In this study, the mechanism and ubiquity of organosulfate formation in biogenic SOA is investigated by a comprehensive seri...

  6. Ruptured Petrous Carotid Pseudoaneurysm Due to Tuberculous Otitis: Endovascular Treatment

    PubMed Central

    Yagci, A.B.; Ardiç, F.N.; Oran, I.; Bir, F.; Karabulut, N.

    2006-01-01

    Summary We report the imaging findings and endovascular treatment in an unusual case of petrous internal carotid artery pseudoaneurysm due to primary tuberculous otitis. The aneurysm was recognized and ruptured during a surgical intervention for otitis. Successful endovascular treatment of the aneurysm was performed by occlusion of the parent vessel using detachable balloon and coils. PMID:20569552

  7. Melioidosis presenting as an infected intrathoracic subclavian artery pseudoaneurysm treated with femoral vein interposition graft.

    PubMed

    Schindler, Nancy; Calligaro, Keith D; Dougherty, Matthew J; Diehl, James; Modi, Ketang H; Braffman, Michael N

    2002-03-01

    We present the first case of in situ replacement of an infected subclavian artery using superficial femoral vein and the fourth reported case of an infected arterial pseudoaneurysm caused by pseudomonas pseudomallei. Sepsis and hoarseness developed in a 58-year-old man after recent travel to Borneo, Indonesia. Indirect laryngoscopy revealed a paralyzed right vocal cord. Computed tomography and arteriography revealed a 6.5-cm pseudoaneurysm of the proximal right subclavian artery. Blood cultures grew pseudomonas pseudomallei. An abnormal cardiac stress test prompted a coronary angiography, which revealed severe coronary artery disease.The patient underwent coronary artery bypass and in situ replacement of the infected subclavian artery pseudoaneurysm with a superficial femoral vein, along with placement of a pectoralis major muscle flap to cover the vein graft. Operative cultures of the pseudoaneurysm grew pseudomonas pseudomallei. The patient was treated with a 6-week course of intravenous ceftazidime and oral doxycycline and then continued on oral amoxicillin-clavulanate. One week after discontinuing intravenous antibiotics, the patient presented to the emergency department with a rapidly expanding, pulsatile mass in the right supraclavicular space. He was taken emergently to the operating room. After hypothermic circulatory arrest was accomplished, the disrupted vein graft and aneurysm cavity were resected and the subclavian artery was oversewn proximally and distally. Parenteral ceftazidime was continued for 3 months and oral amoxicillin-clavulanate (augmentin) was continued indefinitely. There was no evidence of infection clinically or by computed tomographic scan 2 years later. Although autogenous vein replacement of infected arteries and grafts may be successful in the majority of cases, this strategy should probably be avoided when particularly virulent bacteria such as the organism in this case are present.

  8. An Infectious Pseudoaneurysm Caused by Ventricular Septal Defect Occluder in Patent Ductus Arteriosus Closure in a Two-Year-Old Child.

    PubMed

    Li, Dingyang; Qiu, Qiu; Jin, Jing; Zhang, Changdong; Wang, Lijun; Zhang, Gangcheng

    2017-12-12

    We present a case of an infectious pseudoaneurysm after patent ductus arteriosus (PDA) closure with a ventricular septal defect (VSD) occluder in a two-year-old child. The aneurysm grew rapidly but was successfully removed in time and the patient survived. To our knowledge, this is the first report of an infectious pseudoaneurysm caused by VSD occluder in PDA closure.

  9. [Rupture of splenic artery pseudoaneurysm: an unusual cause of upper gastrointetinal bleeding].

    PubMed

    Herrera-Fernández, Francisco Antonio; Palomeque-Jiménez, Antonio; Serrano-Puche, Félix; Calzado-Baeza, Salvador Francisco; Reyes-Moreno, Montserrat

    2014-01-01

    Bleeding from a pancreatic pseudocyst is a severe complication after pancreatitis that can lead to a massive gastrointestinal blood loss. Pseudocyst rupture into the stomach is an unusual complication. We report the case of a 34-year-old woman with a history of alcoholism and a pancreatic pseudocyst. One year after follow-up of her pseudocyst, she arrived at the emergency room with an episode of upper gastrointestinal bleeding. An upper digestive endoscopy showed active bleeding in the subcardial fundus, which could not be endoscopically controlled. Abdominal angio-CT confirmed the diagnosis of a splenic artery pseudoaneurysm in close contact with the back wall of the stomach, as well as a likely fistulization of it. The patient was urgently operated and a distal splenopancreatectomy and fistulorrhaphy was performed. The rupture of a splenic artery pseudoaneurysm may rarely present as upper gastrointestinal bleeding. This may be lethal if not urgently treated.

  10. Potential of secondary aerosol formation from Chinese gasoline engine exhaust.

    PubMed

    Du, Zhuofei; Hu, Min; Peng, Jianfei; Guo, Song; Zheng, Rong; Zheng, Jing; Shang, Dongjie; Qin, Yanhong; Niu, He; Li, Mengren; Yang, Yudong; Lu, Sihua; Wu, Yusheng; Shao, Min; Shuai, Shijin

    2018-04-01

    Light-duty gasoline vehicles have drawn public attention in China due to their significant primary emissions of particulate matter and volatile organic compounds (VOCs). However, little information on secondary aerosol formation from exhaust for Chinese vehicles and fuel conditions is available. In this study, chamber experiments were conducted to quantify the potential of secondary aerosol formation from the exhaust of a port fuel injection gasoline engine. The engine and fuel used are common in the Chinese market, and the fuel satisfies the China V gasoline fuel standard. Substantial secondary aerosol formation was observed during a 4-5hr simulation, which was estimated to represent more than 10days of equivalent atmospheric photo-oxidation in Beijing. As a consequence, the extreme case secondary organic aerosol (SOA) production was 426±85mg/kg-fuel, with high levels of precursors and OH exposure. The low hygroscopicity of the aerosols formed inside the chamber suggests that SOA was the dominant chemical composition. Fourteen percent of SOA measured in the chamber experiments could be explained through the oxidation of speciated single-ring aromatics. Unspeciated precursors, such as intermediate-volatility organic compounds and semi-volatile organic compounds, might be significant for SOA formation from gasoline VOCs. We concluded that reductions of emissions of aerosol precursor gases from vehicles are essential to mediate pollution in China. Copyright © 2017. Published by Elsevier B.V.

  11. Direct percutaneous transaortic approach for treatment of aortic pseudoaneurysms.

    PubMed

    Pirelli, Luigi; Kliger, Chad; Fontana, Gregory P; Ruiz, Carlos E

    2015-05-01

    Aortic pseudoaneurysms (APAs) can develop months or years after aortic and cardiac surgery. If not treated appropriately, APAs can lead to fatal complications and ultimately death. We describe a case of a 61-year old patient with a diagnosed large pseudoaneurysm 5 years after his aortic valve surgery, who was treated with a novel transcatheter direct transaortic approach. The patient had dilated cardiomyopathy with an APA adjacent to the lower sternal plate. An Amplatzer septal occlusion device followed by coils was delivered transcutaneously through the APA to close its neck and fill the false aneurysm, respectively. Triple fusion multimodality imaging was used to guide the placement of the occlusion devices. The merging of computed tomography (CT) and echocardiography with real-time fluoroscopy was fundamental in procedural planning and guidance. Post-procedural transoesophageal echocardiogram (TOE) and CT angiography showed complete exclusion of the APA. A direct transaortic approach is a valid option for closure of an APA if the surgical risk is prohibitive, and the use of triple fusion technology is an essential tool in the hands of interventionalists and surgeons for preoperative planning and conduction of these procedures. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  12. [Post Traumatic Pseudoaneurysm of the Hepatic Artery - Clinical report].

    PubMed

    Rolim, Dalila; Sampaio, Sérgio; Almeida Pinto, João; Oliveira, Manuel

    2014-01-01

    Hepatic artery aneurysms are a rare condition that can be fatal if rupture happens. Often, they are incidentally identified in routine imaging. Intervention is indicated when symptomatic, if they reach 2cm or more of size, in patients presenting with multiple hepatic artery aneurysms and in all pseudoaneurysms. We describe the case of a 57 year-old female, to whom a post-traumatic hepatic artery aneurysm was diagnosed. Open surgical repair was successfully accomplished.

  13. Pseudoaneurysm of the Anterior Tibial Artery following Ankle Arthroscopy in a Soccer Player.

    PubMed

    Tonogai, Ichiro; Matsuura, Tetsuya; Iwame, Toshiyuki; Wada, Keizo; Takasago, Tomoya; Goto, Tomohiro; Hamada, Daisuke; Kawatani, Yohei; Fujimoto, Eiki; Kitagawa, Tetsuya; Takao, Shyoichiro; Iwamoto, Seiji; Yamanaka, Moriaki; Harada, Masafumi; Sairyo, Koichi

    2017-01-01

    Ankle arthroscopy carries a lower risk of vascular complications when standard anterolateral and anteromedial portals are used. However, the thickness of the fat pad at the anterior ankle affords little protection for the thin-walled anterior tibial artery, rendering it susceptible to indirect damage during procedures performed on the anterior ankle joint. To our knowledge, only 11 cases of pseudoaneurysm involving the anterior tibial artery after ankle arthroscopy have been described in the literature. Here we reported a rare case of a 19-year-old soccer player who presented with pseudoaneurysm of the anterior tibial artery following ankle arthroscopy using an ankle distraction method and underwent anastomosis for the anterior tibial artery injury. Excessive distraction of the ankle puts the neurovascular structures at greater risk for iatrogenic injury of the anterior tibial artery during ankle arthroscopy. Surgeons should look carefully for postoperative ankle swelling and pain after ankle arthroscopy.

  14. Pseudoaneurysm of the Anterior Tibial Artery following Ankle Arthroscopy in a Soccer Player

    PubMed Central

    Iwame, Toshiyuki; Hamada, Daisuke; Fujimoto, Eiki; Kitagawa, Tetsuya; Takao, Shyoichiro; Iwamoto, Seiji; Yamanaka, Moriaki; Harada, Masafumi

    2017-01-01

    Ankle arthroscopy carries a lower risk of vascular complications when standard anterolateral and anteromedial portals are used. However, the thickness of the fat pad at the anterior ankle affords little protection for the thin-walled anterior tibial artery, rendering it susceptible to indirect damage during procedures performed on the anterior ankle joint. To our knowledge, only 11 cases of pseudoaneurysm involving the anterior tibial artery after ankle arthroscopy have been described in the literature. Here we reported a rare case of a 19-year-old soccer player who presented with pseudoaneurysm of the anterior tibial artery following ankle arthroscopy using an ankle distraction method and underwent anastomosis for the anterior tibial artery injury. Excessive distraction of the ankle puts the neurovascular structures at greater risk for iatrogenic injury of the anterior tibial artery during ankle arthroscopy. Surgeons should look carefully for postoperative ankle swelling and pain after ankle arthroscopy. PMID:28607785

  15. Delayed recurrent nerve paralysis following post-traumatic aortic pseudoaneurysm

    PubMed Central

    Ricciardiello, Filippo; Tafuri, Domenico; Varriale, Roberto; Testa, Domenico

    2016-01-01

    Abstract Blunt trauma to the neck or to the chest are increasingly observed in the emergency clinical practice. They usually follow motor vehicle accidents or may be work or sports related. A wide pattern of clinical presentation can be potentially encountered. We report the uncommon case of a patient who was referred to our observation presenting with hoarseness and disphagia. Twenty days before he had sustained a car accident with trauma to the chest, neck and the mandible. Laryngoscopy showed a left recurrent laryngeal nerve palsy. Further otolaryngo-logical examination showed no other abnormality. At CT and MR imaging a post-traumatic aortic pseudoaneurysm was revealed. The aortic pseudoaneurysm was consequently repaired by implantation of an endovascular stent graft under local anesthesia. The patient was discharged 10 days later. At 30-days follow-up laryngoscopy the left vocal cord palsy was completely resolved. Hoarseness associated with a dilated left atrium in a patient with mitral valve stenosis was initially described by Ortner more than a century ago. Since then several non malignant, cardiovascular, intrathoracic disease that results in embarrassment from recurrent laryngeal nerve palsy usually by stretching, pulling or compression; thus, the correlations of these pathologies was termed as cardiovocal syndrome or Ortner’s syndrome. The reported case illustrates that life-threatening cardiovascular comorbidities can cause hoarseness and that an impaired recurrent laryngeal nerve might be correctable. PMID:28352797

  16. Delayed recurrent nerve paralysis following post-traumatic aortic pseudoaneurysm.

    PubMed

    Mesolella, Massimo; Ricciardiello, Filippo; Tafuri, Domenico; Varriale, Roberto; Testa, Domenico

    2016-01-01

    Blunt trauma to the neck or to the chest are increasingly observed in the emergency clinical practice. They usually follow motor vehicle accidents or may be work or sports related. A wide pattern of clinical presentation can be potentially encountered. We report the uncommon case of a patient who was referred to our observation presenting with hoarseness and disphagia. Twenty days before he had sustained a car accident with trauma to the chest, neck and the mandible. Laryngoscopy showed a left recurrent laryngeal nerve palsy. Further otolaryngo-logical examination showed no other abnormality. At CT and MR imaging a post-traumatic aortic pseudoaneurysm was revealed. The aortic pseudoaneurysm was consequently repaired by implantation of an endovascular stent graft under local anesthesia. The patient was discharged 10 days later. At 30-days follow-up laryngoscopy the left vocal cord palsy was completely resolved. Hoarseness associated with a dilated left atrium in a patient with mitral valve stenosis was initially described by Ortner more than a century ago. Since then several non malignant, cardiovascular, intrathoracic disease that results in embarrassment from recurrent laryngeal nerve palsy usually by stretching, pulling or compression; thus, the correlations of these pathologies was termed as cardiovocal syndrome or Ortner's syndrome. The reported case illustrates that life-threatening cardiovascular comorbidities can cause hoarseness and that an impaired recurrent laryngeal nerve might be correctable.

  17. Percutaneous closure of a giant left ventricular wall pseudoaneurysm: Anterograde approach with a double snare technique.

    PubMed

    Afonso Nogueira, Marta; Fiarresga, António; de Sousa, Lídia; Agapito, Ana; Galrinho, Ana; Cruz Ferreira, Rui

    2016-01-01

    Left ventricular pseudoaneurysm is a rare complication of acute myocardial infarction, cardiac surgery, trauma or infection. Since surgical repair is associated with high morbidity and mortality, percutaneous closure has been described as an alternative. In this regard, we present a case in which a symptomatic large left ventricular pseudoaneurysm was treated by percutaneous closure due to the patient's high surgical risk, using a double snare technique. Despite the technical difficulties, this procedure had a good final result followed by clinical success, confirming that this procedure is an effective alternative to surgery in high-risk patients. Copyright © 2016 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.

  18. SECONDARY ORGANIC AEROSOL FORMATION FROM THE IRRADIATION OF SIMULATED AUTOMOBILE EXHAUST

    EPA Science Inventory

    A laboratory study was conducted to evaluate the potential for secondary organic aerosol formation from emissions from automotive exhaust. The goal was to determine to what extent photochemical oxidation products of these hydrocarbons contribute to secondary organic aerosol (SO...

  19. Endovascular Treatment of a Carotid Dissecting Pseudoaneurysm in a Patient with Ehlers-Danlos Syndrome Type IV with Fatal Outcome

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lim, Siok Ping, E-mail: siokpinglim@yahoo.co.uk; Duddy, Martin J.

    2008-01-15

    We present a patient with Ehlers-Danlos syndrome type IV (EDS IV) with a carotid dissecting pseudoaneurysm causing severe carotid stenosis. This lesion was treated endovascularly. Unfortunately, the patient died of remote vascular catastrophes (intracranial hemorrhage and abdominal aortic rupture). This unique case illustrates the perils of endovascular treatment of EDS IV patients and the need for preoperative screening for concomitant lesions. It also shows that a dissecting pseudoaneurysm can feasibly be treated with a covered stent and that closure is effective using Angioseal in patients with EDS IV.

  20. Stent graft in the treatment of pseudoaneurysms of the hepatic arteries.

    PubMed

    Lü, Peng-Hua; Zhang, Xi-Cheng; Wang, Li-Fu; Chen, Zhao-Lei; Shi, Hai-Bin

    2013-10-01

    The purpose of our study was to evaluate the technical feasibility, procedural complications, clinical follow-up, and computed tomography (CT) scan outcomes of hepatic artery pseudoaneurysms (HAPs) treated with stent graft. Between October 2004 and October 2009, we treated 8 patients with HAPs with stent graft. Stent graft deployment was technically successful in all the patients. Complete exclusion of the pseudoaneurysm preserving patency of the hepatic artery was achieved in 6 patients. Total occlusion of the common hepatic artery was observed in 1 patient, and vasospasm of proper hepatic artery and endoleak from distal stent margin were observed in another patient. The 2 patient were controlled through occlusion parent artery with coils. After these procedures, symptoms of bleeding and abdominal pain disappeared. Follow-up enhanced CT scan was performed at an average of 14 months (range, 6-26 months), which showed complete disappearance of the HAP and patency of the stent without intrastent stenosis in 6 patients who had successful deployment of the stent. Endovascular treatment of HAPs using stent graft can maintain the hepatic artery blood flow and could be considered as an alternative to embolization.

  1. Endovascular Treatment of an Aortoiliac Tuberculous Pseudoaneurysm

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Villegas, Miguel O.; Mereles, Alberto Perez; Tamashiro, Gustavo A.

    2013-04-15

    We report a rare case of a tuberculous mycotic aortoiliac pseudoaneurysm treated with an endovascular procedure and follow-up of 36 months. The patient was a white 72-year-old man with pulmonary tuberculosis and a former smoker with hypertension, chronic renal failure, and dyslipidemia. A computed tomographic scan of the abdomen and pelvis revealed a left paravertebral cavity with fluid content and involvement of vertebrae L2-L4. After a surgical repair attempt, the patient was treated with the implant of a bifurcated endoprosthesis. Because it is unlikely that any center has extensive experience in the management of this rare manifestation of the disease,more » we reviewed the literature for similar cases.« less

  2. Efficacy and safety of closing postcatheterisation pseudoaneurysms with ultrasound-guided thrombin injections using two approaches: bolus versus slow injection. A prospective randomised trial.

    PubMed

    Lewandowski, Paweł; Maciejewski, Paweł; Wąsek, Wojciech; Pasierski, Tomasz; Budaj, Andrzej

    2011-01-01

    Thrombin injection is a widely accepted treatment of an iatrogenic arterial pseudoaneurysm. However, the optimal mode of injection and type of pseudoaneurysm amenable to this therapy have yet been established. To compare efficacy and safety of two approaches to ultrasound-guided thrombin injections into a femoral artery pseudoaneurysm with or without long neck that developed as an iatrogenic complication of cardiac catheterisation. Patients were randomised to thrombin administration in a bolus or slow injection. The length and width of aneurysm neck and blood flow velocity in the neck were measured with color Doppler ultrasonography before the closure procedure. Thrombin dose, time to thrombotic occlusion, blood oxygen saturation in a toe of the extremity with the pseudoaneurysm (a marker of silent microembolisation), and clinical signs of distal embolisation were recorded. Between 2006 and 2009, 73 consecutive patients (33 males; mean age 67.8 ± 11.9 years) with femoral pseudoaneurysms complicating cardiac catheterisation were randomised into two groups that were treated with thrombin bolus (n = 40) or slow injection (n = 33). The efficacy of aneurysm closure with either method was similarly high (100% vs 96.8%, NS, respectively) and did not depend on the length and width of the aneurysm neck. Independent risk factors for distal embolisation were: thrombin dose (OR 4.2; 95% CI 0.92-19.3), the length of aneurysm neck (OR 4.66; 95% CI 1.1-19.9), age above 80 years (OR 10.9; 95% CI 1.0-116.8), and bolus treatment (OR 7.6; 95% CI 1.3-44.9). We observed silent microembolisation phenomenon that was common (occurring in 38% of patients in the bolus group vs 33% of patients in the slow injection group) but in most cases asymptomatic. Femoral pseudoaneurysm closure with a low dose of thrombin is a valid and beneficial treatment. Either method (bolus or slow injection) was similarly efficacious and safe even in the subgroup of patients with neckless aneurysms. We observed

  3. Pseudoaneurysm of the articular branch of the descending genicular artery following double-bundle anterior cruciate ligament reconstruction.

    PubMed

    Tsubosaka, Masanori; Matsushita, Takehiko; Kuroda, Ryosuke; Matsumoto, Tomoyuki; Kurosaka, Masahiro

    2017-09-01

    This report describes a case of a pseudoaneurysm of the articular branch of the descending genicular artery following double-bundle anterior cruciate ligament (ACL) reconstruction. An 18-year-old male received double-bundle ACL reconstruction. During ACL reconstruction, a far anteromedial portal was created for femoral tunnel drilling. The patient presented with pulsatile swelling on the medial side of the knee on the second post-operative day. The pseudoaneurysm was diagnosed using contrast computed tomography and Doppler ultrasonography and was subsequently treated by embolization with a microcatheter. Although a vascular injury is a very rare complication of knee arthroscopy, it should be considered a possibility in patients who undergo such procedures. V.

  4. Glyoxal-methylglyoxal cross-reactions in secondary organic aerosol formation.

    PubMed

    Schwier, Allison N; Sareen, Neha; Mitroo, Dhruv; Shapiro, Erica L; McNeill, V Faye

    2010-08-15

    Glyoxal (G) and methylglyoxal (MG) are potentially important secondary organic aerosol (SOA) precursors. Previous studies of SOA formation by G and MG have focused on either species separately; however, G and MG typically coexist in the atmosphere. We studied the formation of secondary organic material in aqueous aerosol mimic mixtures containing G and MG with ammonium sulfate. We characterized the formation of light-absorbing products using UV-vis spectrophotometry. We found that absorption at 280 nm can be described well using models for the formation of light-absorbing products by G and MG in parallel. Pendant drop tensiometry measurements showed that surface tension depression by G and MG in these solutions can be modeled as a linear combination of the effects of G and MG alone. Product species were identified using chemical ionization mass spectrometry with a volatilization flow tube inlet (Aerosol CIMS). Peaks consistent with G-MG cross-reaction products were observed, accounting for a significant fraction of detected product mass, but most peaks could be attributed to self-reaction. We conclude that cross-reactions contribute to SOA mass from uptake of G and MG, but they are not required to accurately model the effects of this process on aerosol surface tension or light absorption.

  5. Subacute Staphylococcus epidermidis Bacterial Endocarditis Complicated by Mitral-Aortic Intervalvular Fibrosa Pseudoaneurysm

    DTIC Science & Technology

    2012-12-01

    Staphylococcus epidermidis Bacterial Endocarditis Complicated byMitral-Aortic Intervalvular Fibrosa Pseudoaneurysm Diane Elegino-Steffens,1 Amy Stratton,1... endocarditis . 1. Introduction The mitral-aortic intervalvular fibrosa (MAIF), also known as the mitral-aortic membrane, is a fibrous region of the heart...of his aortic valve for severe aortic regurgitation that was subsequently found to have infective endocarditis prompting antibiotic treatment. His

  6. Covered stent graft for treatment of a pseudoaneurysm and carotid blowout syndrome

    PubMed Central

    Janjua, Nazli; Alkawi, Ammar; Georgiadis, Alexandros L.; Kirmani, Jawad F.; Qureshi, Adnan I.

    2008-01-01

    Background Carotid blowout syndrome with pseudoaneurysm, a rapidly progressive pathology, may present emergently with massive oral hemorrhage. Use of an endograft prosthesis offers a treatment strategy with salvation of the carotid artery. Case History: A 55 year old man with advanced squamous cell carcinoma of the head and neck presented with recurrent transoral hemorrhage, requiring endovascular treatment. Technical Report: Coil embolization was initially performed with little impact on the hemorrhage. A 7 x 40 mm Fluency® Plus covered stent (Bard Peripheral Vascular, Tempe, Arizona, USA) was placed and was supplemented by a second 8 x 40 mm Fluency Plus stent, with resulting cessation of active contrast extravasation. Discussion: The risks and benefits of various treatment options of carotid pseudoaneurysm with blowout are discussed including the use or omission of antiplatelet and anticoagulant regimens, with reference to previously reported cases. Conclusion: Tandem, overlapping covered stent placement in the common carotid artery is feasible and offers a treatment option for carotid blowout syndrome. Risks of aggravation of hemorrhage versus long-term thromboembolic events without antiplatelet therapy must be considered in cases of active ongoing hemorrhage. PMID:22518207

  7. [Secondary metabolites accumulating and geoherbs formation under enviromental stress].

    PubMed

    Huang, Lu-Qi; Guo, Lan-Ping

    2007-02-01

    This paper analyzed how habitat affected the formation of geoherbs after summarizing the influences of environmental stress on plants growth, especially on theirs secondary metabolites accumulating, and introducing 4 kinds hypothesis about environmental stress affects plants. It was then pointed out that environmental stress may have advantage on the formation of geoherbs. The stress effect hypothesis on forming geoherbs was brought forward, and the ways and methods on study the geoherbs under environmental stress was discussed.

  8. Alternative Format Preferences among Secondary School Visually Impaired Students in Nigeria

    ERIC Educational Resources Information Center

    Adetoro, 'Niran

    2012-01-01

    Persons with visual impairment have consistently shown a preference for one alternative reading format over another, often because of factors outside their control. This study adopted survey research design to investigate alternative format preferences among secondary school visually impaired students, focusing on Southwestern Nigeria. Using total…

  9. NDMA formation in secondary wastewater effluent.

    PubMed

    Hatt, J W; Lamy, C; Germain, E; Tupper, M; Judd, S J

    2013-03-01

    Concern over prospective levels of N-nitrosodimethylamine (NDMA) in waters has increased in recent years due to its disinfection byproduct formation potential from chloramination. It has been mooted that this is promoted by organic precursors from municipal wastewaters, such that there is a more significant risk of excessive levels in water reuse applications. Experiments conducted on chloramination and chlorination of secondary wastewater have confirmed that that significant NDMA formation arises only from chloramination, with its concentration varying with test conditions used. A full factor analysis revealed all parameters studied (temperature, pH, monochloramine dose and contact time), both individually and synergistically, to have a statistically significant impact on NDMA formation with contact time being the most important. At raw water temperatures below 10 °C, the NDMA concentration can be minimised to below the 10 ng L(-1) threshold by not exceeding a monochloramine dose of 2 mg L(-1) as Cl(2). However, at higher water temperatures other measures are required to suppress NDMA formation, such as reducing the contact time (which could prove impractical in most applications) or maintaining a pH below 6. Further trials are required to fully develop the operating envelope to ensure NDMA concentrations do not exceed the 10 ng L(-1) threshold, or else to identify effective pretreatment methods for removing the NDMA precursors. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Engineering the formation of secondary building blocks within hollow interiors.

    PubMed

    Li, Xiaobo; Liu, Xiao; Ma, Yi; Li, Mingrun; Zhao, Jiao; Xin, Hongchuan; Zhang, Lei; Yang, Yan; Li, Can; Yang, Qihua

    2012-03-15

    Secondary building blocks within the cavities of primary silica-architecture building blocks are successfully engineered. The immobilized surfactant directs the selective dissolution and reassembly of dissolved silicate species for the formation of secondary building blocks (hollow nanospheres/nanorods; see figure). Supported TiO(2) on nanostructures with multilevel interiors is shown to exhibit significantly enhanced activity in photocatalytic H(2) production. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Aortic valve replacement and repair of left ventricular pseudoaneurysm in a Jehovah’s Witness

    PubMed Central

    Perrotti, Andrea; Vaislic, Claude; Chocron, Sidney

    2013-01-01

    The preoperative and surgical management of a giant left ventricular pseudoaneurysm(LVP) associated with aortic valve replacement in a 76 year old male Jehovah’s Witness patient is reported. The satisfactory recovery observed in this patient demonstrates the feasibility of this complex surgical procedure even in this particular patient population. PMID:25478494

  12. Perineal Pseudoaneurysm from Traumatic Foley Removal Leads to Recurrent Life-Threatening Hematuria.

    PubMed

    Liang, Lorraine Min-Shan; Xue, Jingbing; Erturk, Erdal

    2015-01-01

    Hematuria resulting from urethral traumatic catheter insertion and removal is often encountered. Usually, hematuria resolves with conservative measures. We report a case of traumatic Foley removal leading to intermittent life-threatening hematuria resulting in blood loss anemia requiring multiple transfusions and multiple episodes of hypotension requiring pressors. A pelvic angiogram revealed a pseudoaneurysm of the left pudendal artery, which was treated with microcoil embolization leading to resolution of bleeding.

  13. Percutaneous Direct Needle Puncture and Transcatheter N-butyl Cyanoacrylate Injection Techniques for the Embolization of Pseudoaneurysms and Aneurysms of Arteries Supplying the Hepato-pancreato-biliary System and Gastrointestinal Tract

    PubMed Central

    Yadav, Rajanikant R; Boruah, Deb K; Bhattacharyya, Vishwaroop; Prasad, Raghunandan; Kumar, Sheo; Saraswat, V A; Kapoor, V K; Saxena, Rajan

    2016-01-01

    Aims: The aim of this study was to evaluate the safety and clinical efficacy of percutaneous direct needle puncture and transcatheter N-butyl cyanoacrylate (NBCA) injection techniques for the embolization of pseudoaneurysms and aneurysms of arteries supplying the hepato-pancreato-biliary (HPB) system and gastrointestinal (GI) tract. Subjects and Methods: A hospital-based cross-sectional retrospective study was conducted, where the study group comprised 11 patients with pseudoaneurysms/aneurysms of arteries supplying the HPB system and GI tract presenting to a tertiary care center from January 2015 to June 2016. Four patients (36.4%) underwent percutaneous direct needle puncture of pseudoaneurysms with NBCA injection, 3 patients (27.3%) underwent transcatheter embolization with NBCA as sole embolic agent, and in 4 patients (36.4%), transcatheter NBCA injection was done along with coil embolization. Results: This retrospective study comprised 11 patients (8 males and 3 females) with mean age of 35.8 years ± 1.6 (standard deviation [SD]). The mean volume of NBCA: ethiodized oil (lipiodol) mixture injected by percutaneous direct needle puncture was 0.62 ml ± 0.25 (SD) (range = 0.5–1 ml), and by transcatheter injection, it was 0.62 ml ± 0.37 (SD) (range = 0.3–1.4 ml). Embolization with NBCA was technically and clinically successful in all patients (100%). No recurrence of bleeding or recurrence of pseudoaneurysm/aneurysm was noted in our study. Conclusions: Percutaneous direct needle puncture of visceral artery pseudoaneurysms and NBCA glue injection and transcatheter NBCA injection for embolization of visceral artery pseudoaneurysms and aneurysms are cost-effective techniques that can be used when coil embolization is not feasible or has failed. PMID:28123838

  14. Embolization with Onyx® of an arterial pseudoaneurysm with an arteriovenous fistula complicating a percutaneous nephrolithotomy: A case report and review of literature.

    PubMed

    Simões Ferreira, Ana Isabel; Gomes, Filipe Veloso; Bilhim, Tiago; Coimbra, Élia

    2018-01-01

    Percutaneous nephrolithotomy (PCNL) has proven very effective in the management of renal stones. However, complications are not so rare, and bleeding is one of the most worrisome; it has a reported incidence of 1%-3% and may happen during track dilatation. In addition, arterial pseudoaneurysms and/or arteriovenous fistulas (AVF) may occur. We report the case of a patient with an intrarenal pseudoaneurysm associated with an AVF, after PCNL. Superselective endovascular embolization with Onyx ® was successfully performed, achieving exclusion of the pseudoaneurysm and AVF with preservation of the remaining vascularization of the kidney. We review the literature regarding endovascular management of kidney vascular lesions after PCNL. Selective renal embolization is a minimally invasive procedure, highly effective with a low incidence of complications. Currently, it is considered the most appropriate technique in the treatment of arterial iatrogenic complications following percutaneous renal procedures. Onyx ® is an effective, easy to handle, and safe alternative embolic agent for these procedures.

  15. Uncommon Case of a Post-Traumatic Portal Vein Pseudoaneurysm Treated with Percutaneous Transhepatic Stent Grafting

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ierardi, Anna Maria, E-mail: amierardi@yahoo.it; Berselli, Mattia, E-mail: mattia.berselli@ospedale.varese.it; Cuffari, Salvatore, E-mail: salvatore.cuffari@ospedale.varese.it

    We describe a man who presented with a traumatic portal vein pseudoaneurysm, which was subsequently managed with a percutaneous transhepatic stent graft. This case demonstrates a rarely seen condition in the traumatic population and a novel management strategy, which should be considered in the management of this challenging injury.

  16. Radiosurgery-induced anterior inferior cerebellar artery pseudoaneurysm treated with trapping and bypass.

    PubMed

    Umekawa, Motoyuki; Hasegawa, Hirotaka; Shin, Masahiro; Kawashima, Mariko; Nomura, Seiji; Nakatomi, Hirofumi; Saito, Nobuhito

    2018-05-02

    Stereotactic radiosurgery (SRS) is an established modality for the treatment of vestibular schwannomas (VSs). However, its long-term vascular complications have not been well-studied. Among the 360 patients who underwent SRS for VS in our institution and lived for >5 years thereafter, we identified only 1 patient who exhibited complication due to a late-onset aneurysm; thus, the incidence was roughly estimated to be 0.3%. The patient was a 78-year-old man who had undergone SRS for a right VS, and presented with right peripheral facial palsy 19 years later. Radiographic examinations revealed a distal anterior inferior cerebellar artery (AICA) fusiform aneurysm, which was embedded in the tumor, and progressively enlarged over 17 months. Although the right AICA perfused a large area of the cerebellum, the aneurysm was successfully treated with AICA trapping, in conjunction with an occipital artery-AICA bypass. Distal AICA pseudoaneurysm formation is a rare, but potentially severe, late complication after SRS for VS. This is the first case that successfully treated this pathology with AICA trapping with occipital artery-AICA bypass. Copyright © 2018. Published by Elsevier Inc.

  17. Fuel composition and secondary organic aerosol formation: gas-turbine exhaust and alternative aviation fuels.

    PubMed

    Miracolo, Marissa A; Drozd, Greg T; Jathar, Shantanu H; Presto, Albert A; Lipsky, Eric M; Corporan, Edwin; Robinson, Allen L

    2012-08-07

    A series of smog chamber experiments were performed to investigate the effects of fuel composition on secondary particulate matter (PM) formation from dilute exhaust from a T63 gas-turbine engine. Tests were performed at idle and cruise loads with the engine fueled on conventional military jet fuel (JP-8), Fischer-Tropsch synthetic jet fuel (FT), and a 50/50 blend of the two fuels. Emissions were sampled into a portable smog chamber and exposed to sunlight or artificial UV light to initiate photo-oxidation. Similar to previous studies, neat FT fuel and a 50/50 FT/JP-8 blend reduced the primary particulate matter emissions compared to neat JP-8. After only one hour of photo-oxidation at typical atmospheric OH levels, the secondary PM production in dilute exhaust exceeded primary PM emissions, except when operating the engine at high load on FT fuel. Therefore, accounting for secondary PM production should be considered when assessing the contribution of gas-turbine engine emissions to ambient PM levels. FT fuel substantially reduced secondary PM formation in dilute exhaust compared to neat JP-8 at both idle and cruise loads. At idle load, the secondary PM formation was reduced by a factor of 20 with the use of neat FT fuel, and a factor of 2 with the use of the blend fuel. At cruise load, the use of FT fuel resulted in no measured formation of secondary PM. In every experiment, the secondary PM was dominated by organics with minor contributions from sulfate when the engine was operated on JP-8 fuel. At both loads, FT fuel produces less secondary organic aerosol than JP-8 because of differences in the composition of the fuels and the resultant emissions. This work indicates that fuel reformulation may be a viable strategy to reduce the contribution of emissions from combustion systems to secondary organic aerosol production and ultimately ambient PM levels.

  18. Perineal Pseudoaneurysm from Traumatic Foley Removal Leads to Recurrent Life-Threatening Hematuria

    PubMed Central

    Xue, Jingbing; Erturk, Erdal

    2015-01-01

    Abstract Hematuria resulting from urethral traumatic catheter insertion and removal is often encountered. Usually, hematuria resolves with conservative measures. We report a case of traumatic Foley removal leading to intermittent life-threatening hematuria resulting in blood loss anemia requiring multiple transfusions and multiple episodes of hypotension requiring pressors. A pelvic angiogram revealed a pseudoaneurysm of the left pudendal artery, which was treated with microcoil embolization leading to resolution of bleeding. PMID:27579388

  19. The minimally invasive management of visceral artery aneurysms and pseudoaneurysms.

    PubMed

    Fankhauser, Grant T; Stone, William M; Naidu, Sailendra G; Oderich, Gustavo S; Ricotta, Joseph J; Bjarnason, Haraldur; Money, Samuel R

    2011-04-01

    Minimally invasive methods (MIMs) are now available for the management of visceral artery aneurysms and pseudoaneurysms (visceral artery aneurysms [VAA]). The purpose of this study was to review our 10-year experience with the MIM of treating VAA. All patients evaluated from June 1999 to June 2009 with VAAs were reviewed. Demographics, therapy, and results were analyzed. MIM was attempted in 185 aneurysms in 176 patients. Initial intervention was successful in 98% ofaneurysms. Sixty-three (34%) aneurysms were located in the splenic artery, 56 (30%) in the hepatic, 28 (15%) in the gastroduodenal, 16 (8.6%) in the pancreaticoduodenal, six (3.2%) in the superior mesenteric, four (2.1%) in the gastric, four (2.1%) in the celiac, four (2.1%) in the gastroepiploic, two (1%) in the inferior mesenteric, and one (0.5%) in the middle colic artery. Pseudoaneurysms were more common than true aneurysms (64% vs 36%). Bleeding was the indication for intervention in 86 aneurysms (46%). Initial treatment was successful in 177 aneurysms (98%). Reintervention was required in five (3%) aneurysms within 30 days. Coiling was used alone in 139 aneurysms (75%) and in combination with at least one other technique in 20 (11%) cases. Thirty-day aneurysm-related mortality was 3.4% (six deaths). Five additional deaths occurred during 30-day follow-up, although none was related to complications of the aneurysms (2.8%). MIM for visceral artery aneurysms can be used alone or in combination to effectively treat VAAs in elective or emergent conditions. Copyright © 2011 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.

  20. A Review of Secondary Organic Aerosol (SOA) Formation from Isoprene

    EPA Science Inventory

    Recent field and laboratory evidence indicates that the oxidation of isoprene forms secondary organic aerosol (SOA). Global biogenic emissions of isoprene (600 Tg yr-1) are sufficiently large the formation of SOA is even small yields results in substantial production ...

  1. EFFECT OF ACIDITY ON SECONDARY ORGANIC AEROSOL FORMATION FROM ISOPRENE

    EPA Science Inventory

    The effect of particle-phase acidity on secondary organic aerosol (SOA) formation from isoprene is investigated in a laboratory chamber study, in which the acidity of the inorganic seed aerosol was controlled systematically. The observed enhancement in SOA mass concentration is c...

  2. Spatially and temporally restricted expression of PtrMYB021 regulates secondary cell wall formation in Arabidopsis

    DOE PAGES

    Wang, Wei; Li, Eryang; Porth, Ilga; ...

    2016-02-02

    Among the R2R3 MYB transcription factors that involve in the regulation of secondary cell wall formation in Arabidopsis, MYB46 alone is sufficient to induce the entire secondary cell wall biosynthesis program. PtrMYB021, the poplar homolog of MYB46, has been reported to regulate secondary cell wall formation when expressed in Arabidopsis. We report here that spatially and temporally restricted expression of PtrMYB021 is critical for its function in regulating secondary cell wall formation. By using quantitative RT-PCR, we found that PtrMYB021 was expressed primarily in xylem tissues. When expressed in Arabidopsis under the control of PtrCesA8, but not the 35S promoter,more » PtrMYB021 increased secondary cell wall thickness, which is likely caused by increased lignification as well as changes in cell wall carbohydrate composition. Consistent with this, elevated expression of lignin and cellulose biosynthetic genes were observed in the transgenic plants. Finally, when expressed in Arabidopsis protoplasts as fusion proteins to the Gal4 DNA binding domain, PtrMYB021 activated the reporter gene Gal4-GUS. In summary, our results suggest that PtrMYB021 is a transcriptional activator, and spatially and temporally restricted expression of PtrMYB021 in Arabidopsis regulates secondary cell wall formation by activating a subset of secondary cell wall biosynthesis genes.« less

  3. Spatially and temporally restricted expression of PtrMYB021 regulates secondary cell wall formation in Arabidopsis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wang, Wei; Li, Eryang; Porth, Ilga

    Among the R2R3 MYB transcription factors that involve in the regulation of secondary cell wall formation in Arabidopsis, MYB46 alone is sufficient to induce the entire secondary cell wall biosynthesis program. PtrMYB021, the poplar homolog of MYB46, has been reported to regulate secondary cell wall formation when expressed in Arabidopsis. We report here that spatially and temporally restricted expression of PtrMYB021 is critical for its function in regulating secondary cell wall formation. By using quantitative RT-PCR, we found that PtrMYB021 was expressed primarily in xylem tissues. When expressed in Arabidopsis under the control of PtrCesA8, but not the 35S promoter,more » PtrMYB021 increased secondary cell wall thickness, which is likely caused by increased lignification as well as changes in cell wall carbohydrate composition. Consistent with this, elevated expression of lignin and cellulose biosynthetic genes were observed in the transgenic plants. Finally, when expressed in Arabidopsis protoplasts as fusion proteins to the Gal4 DNA binding domain, PtrMYB021 activated the reporter gene Gal4-GUS. In summary, our results suggest that PtrMYB021 is a transcriptional activator, and spatially and temporally restricted expression of PtrMYB021 in Arabidopsis regulates secondary cell wall formation by activating a subset of secondary cell wall biosynthesis genes.« less

  4. Root growth, secondary root formation and root gravitropism in carotenoid-deficient seedlings of Zea mays L

    NASA Technical Reports Server (NTRS)

    Ng, Y. K.; Moore, R.

    1985-01-01

    The effect of ABA on root growth, secondary-root formation and root gravitropism in seedlings of Zea mays was investigated by using Fluridone-treated seedlings and a viviparous mutant, both of which lack carotenoids and ABA. Primary roots of seedlings grown in the presence of Fluridone grew significantly slower than those of control (i.e. untreated) roots. Elongation of Fluridone-treated roots was inhibited significantly by the exogenous application of 1 mM ABA. Exogenous application of 1 micromole and 1 nmole ABA had either no effect or only a slight stimulatory effect on root elongation, depending on the method of application. The absence of ABA in Fluridone-treated plants was not an important factor in secondary-root formation in seedlings less than 9-10 d old. However, ABA may suppress secondary-root formation in older seedlings, since 11-d-old control seedlings had significantly fewer secondary roots than Fluridone-treated seedlings. Roots of Fluridone-treated and control seedlings were graviresponsive. Similar data were obtained for vp-9 mutants of Z. mays, which are phenotypically identical to Fluridone-treated seedlings. These results indicate that ABA is necessary for neither secondary-root formation nor for positive gravitropism by primary roots.

  5. Secondary eyewall formation as a progressive boundary layer response

    NASA Astrophysics Data System (ADS)

    Abarca, S. F.; Montgomery, M. T.; Bell, M. M.

    2012-12-01

    The robust observational (satellite based) evidence that secondary eyewalls are common features in major hurricanes contrasts with the scarce in situ observations of the phenomena and its life cycle. This lack of observations has resulted in an incomplete understanding of the dynamics of secondary eyewall formation (SEF). A wide variety of physical processes have been invoked to explain SEF, but only the recently proposed theory of a progressive boundary layer control in SEF has been supported by a variety of full physics mesoscale numerical integrations. The RAINEX field project provided unique observations of the secondary eyewall of Hurricane Rita (2005) both before and during the time Rita exhibited a clear secondary eyewall structure. These observations have contributed to the advancement of the understanding of the secondary eyewall phenomenon. However, in the RAINEX experiment, there was limited data sampling during the development of the secondary wind maxima, thereby precluding a complete observational investigation of the dynamics of SEF. In this presentation we adopt an azimuthally-averaged perspective of the flow dynamics and we test the newly proposed theory of a progressive boundary layer control on SEF. Specifically, we use both RAINEX data as well as data from high resolution, full physics mesoscale numerical simulations to initialize and force an axisymmetric slab boundary layer model with radial diffusion included. The objective is to investigate whether such a reduced boundary layer model can generate secondary wind maxima as a response to environments like those that result in SEF in nature and in full physics simulations.

  6. Endovascular Treatment of Anastomotic Pseudoaneurysms after Aorto-iliac Surgical Reconstruction

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lagana, Domenico, E-mail: donlaga@gmail.com; Carrafiello, Gianpaolo; Mangini, Monica, E-mail: monica.mangini@tin.it

    Purpose. To assess the effectiveness of endovascular treatment of anastomotic pseudoaneurysms (APAs) following aorto-iliac surgical reconstruction. Materials. We retrospectively evaluated 21 men who, between July 2000 and March 2006, were observed with 30 APAs, 13 to the proximal anastomosis and 17 to the distal anastomosis. The patients had had previous aorto-iliac reconstructive surgery with a bypass due to aneurysm (15/21) or obstructive disease (6/21). The following devices were used: 12 bifurcated endoprostheses, 2 aorto-monoiliac, 4 aortic extenders, 1 stent-graft leg, and 2 covered stents. Follow-up was performed with CT angiography at 1, 3, and 6 months after the procedure andmore » yearly thereafter. Results. Immediate technical success was 100%. No periprocedural complications occurred. Four patients died during follow-up from causes not related to APA, and 1 (treated for prosthetic-enteric fistula) from sepsis 3 months after the procedure. During a mean follow-up of 19.7 months (range 1-72 months), 2 of 21 occlusions of stent-graft legs occurred 3 and 24 months after the procedure (treated with thrombolysis and percutaneous transluminal angioplasty and femorofemoral bypass, respectively) and 1 type I endoleak. Primary clinical success rate was 81% and secondary clinical success was 91%. Conclusion. Endovascular treatment is a valid alternative to open surgery and can be proposed as the treatment of choice for APAs, especially in patients who are a high surgical risk. Further studies with larger series and longer follow-up are necessary to confirm the long-term effectiveness of this approach.« less

  7. Evidence that Blueberry Floral Extracts Influence Secondary Conidiation and Appressorial Formation of Colletotrichum fioriniae.

    PubMed

    Waller, Timothy J; Vaiciunas, Jennifer; Constantelos, Christine; Oudemans, Peter V

    2018-05-01

    Blueberry anthracnose, caused by Colletotrichum fioriniae, is a pre- and postharvest disease of cultivated highbush blueberry (Vaccinium corymbosum). During disease development, the pathogen undergoes several lifestyle changes during host colonization, including epiphytic, quiescent, and necrotrophic phases. It is not clear, however, what if any host signals alter the pattern of colonization during the initial epiphytic phase and infection. This research investigated the role of blueberry floral extracts (FE) on fungal development. Results show that FE significantly increased both the quantity and rate of secondary conidiation and appressorial formation in vitro, suggesting that floral components could decrease the minimum time required for infection. Activity of FE was readily detected in water collected from field samples, where secondary conidiation and appressorial formation decreased as rainwater collections were further removed from flowers. A comparison of FE from four blueberry cultivars with different levels of field susceptibility revealed that appressorial formation but not secondary conidiation significantly increased with the FE from susceptible cultivars versus resistant cultivars. Inoculum supplemented with FE produced higher levels of disease on ripe blueberry fruit as compared with inoculum with water only. Flowers from other ericaceous species were found to also induce secondary conidiation and appressorial formation of C. fioriniae. This research provides strong evidence that flowers can contribute substantially to the infection process of C. fioriniae, signifying the importance of the bloom period for developing effective disease management strategies.

  8. Delayed diagnosis of a pseudoaneurysm with recurrent hemarthrosis of the knee joint.

    PubMed

    Becher, Christoph; Burger, Ulrike L; Allenberg, Jens R; Kaufmann, Guenter W; Thermann, Hajo

    2008-06-01

    This is a case report of recurrent hemarthrosis of the knee joint over 3 months. The patient, a 47-year-old male had three arthroscopic procedures with multiple joint punctures over a 3-month-period prior to our initial consultation. The first procedure (arthroscopic synovectomy) was done for suspected infection following a series of hyaluronic acid injections. Recurrent hemarthrosis developed subsequent to this. Upon further evaluation, a pseudoaneurysm of the superior middle genicular artery was detected and successfully treated with selective angiographic embolization.

  9. Hepatic pseudoaneurysm after traumatic liver injury; is CT follow-up warranted?

    PubMed

    Østerballe, Lene; Helgstrand, Frederik; Axelsen, Thomas; Hillingsø, Jens; Svendsen, Lars Bo

    2014-01-01

    Hepatic pseudoaneurysm (HPA) is a rare complication after liver trauma, yet it is potentially fatal, as it can lead to sudden severe haemorrhage. The risk of developing posttraumatic HPA is one of the arguments for performing follow-up CT of patients with liver injuries. The aim of this study was to investigate the occurrence of HPA post liver trauma. A retrospective study from 2000-2010 of conservatively treated patients with blunt liver trauma was performed to investigate the incidence and nature of HPA. After the initial CT scan patients were admitted to the department and if not clinically indicated prior a follow-up CT was performed on day 4-5. A total of 259 non-operatively managed patients with liver injury were reviewed. 188 had a follow-up CT or US and in 7 patients a HPA was diagnosed. All aneurysms were treated with angiographic embolization and there were no treatment failures. There was no correlation between the severity of the liver injury and development of HPA. 5 out of 7 patients were asymptomatic and would have been discharged without treatment if the protocol did not include a default follow-up CT. In conclusion, this study shows that HPA is not correlated to the severity of liver injury and it develops in 4% of patients after traumatic liver injury. In order to avoid potentially life-threatening haemorrhage from a post trauma hepatic pseudoaneurysm, it seems appropriate to do follow-up CT as part of the conservative management of blunt and penetrating liver injuries.

  10. Interventional Radiology Management of a Ruptured Lumbar Artery Pseudoaneurysm after Cryoablation and Vertebroplasty of a Lumbar Metastasis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Giordano, Aldo Victor; Arrigoni, Francesco, E-mail: arrigoni.francesco@gmail.com; Bruno, Federico

    We describe the management of a complication (a lumbar artery pseudoaneurysm and its rupture) after combined procedure (cryoablation and vertebroplasty) on a lumbar (L2) metastasis from renal cell carcinoma. Review of the literature is also presented with discussion about the measures to be taken to prevent these types of complications.

  11. Endovascular Treatment of a Ruptured Internal Thoracic Artery Pseudoaneurysm Presenting as a Massive Hemothorax in a Patient with Type I Neurofibromatosis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kim, Soo Jin; Kim, Chang Won, E-mail: radkim@hanafos.com; Kim, Suk

    We report a case of acute hemothorax caused by a left internal thoracic artery pseudoaneurysm rupture in a patient with neurofibromatosis type I, which was successfully treated with endovascular coil embolization.

  12. Transarterial Embolization of an Inferior Genicular Artery Pseudoaneurysm with Arteriovenous Fistula after Arthroscopy

    PubMed Central

    Perendreu, Joan; Fortuño, Jose Ramón; Branera, Jordi; Falcó, Joan

    2007-01-01

    Arthroscopic meniscectomy of the knee is generally a safe and effective procedure with a low rate of vascular complications. We report here on a unique case of a 55-year-old man with a lateral inferior genicular artery pseudoaneurysm and a concomitant arteriovenous fistula that developed after arthroscopic meniscectomy; this was successfully treated with selective angiographic embolization. This case illustrates the effectiveness of an endovascular approach as a minimally invasive treatment for this uncommon complication that occurs after an arthroscopic procedure. PMID:17420636

  13. Transarterial embolization of an inferior genicular artery pseudoaneurysm with arteriovenous fistula after arthroscopy.

    PubMed

    Puig, Josep; Perendreu, Joan; Fortuño, Jose Ramón; Branera, Jordi; Falcó, Joan

    2007-01-01

    Arthroscopic meniscectomy of the knee is generally a safe and effective procedure with a low rate of vascular complications. We report here on a unique case of a 55-year-old man with a lateral inferior genicular artery pseudoaneurysm and a concomitant arteriovenous fistula that developed after arthroscopic meniscectomy; this was successfully treated with selective angiographic embolization. This case illustrates the effectiveness of an endovascular approach as a minimally invasive treatment for this uncommon complication that occurs after an arthroscopic procedure.

  14. Unusual Presentation of Melioidosis in a Case of Pseudoaneurysm of Descending Thoracic Aorta: Review of Two Case Reports

    PubMed Central

    Padmaja, Kanne; Lakshmi, Vemu; Sudhaharan, Sukanya; Venkata Surya Malladi, Subbalaxmi; Gopal, Palanki; Venkata Ravinuthala, Kumar

    2015-01-01

    Introduction: Melioidosis is a rapidly fatal infectious disease caused by Burkholderia pseudomallei, an agent of potential biothreat, endemic in several parts of India. Most melioidosis-induced infected aneurysms are located in the abdominal or thoracic aorta. Case Presentation: We reported two unusual cases of melioidosis resulting in pseudoaneurysm of the descending thoracic aorta. In both cases, blood cultures yielded B. pseudomallei. The first patient was managed with resection of aneurysm and reconstruction with Dacron graft followed by medical treatment and was discharged uneventfully. The second patient died within one week of admission before the infecting etiological agent was identified and aneurysmal repair was planned. Conclusions: A high clinical index of suspicion, especially in areas of endemicity is essential for timely management of intracavitary infected pseudoaneurysms caused by B. pseudomallei and use of rapid microbiological techniques, such as bact/alert 3D system, which enables rapid and early recovery of the etiological agent. PMID:26380820

  15. Time-resolved characterization of primary particle emissions and secondary particle formation from a modern gasoline passenger car

    NASA Astrophysics Data System (ADS)

    Karjalainen, Panu; Timonen, Hilkka; Saukko, Erkka; Kuuluvainen, Heino; Saarikoski, Sanna; Aakko-Saksa, Päivi; Murtonen, Timo; Bloss, Matthew; Dal Maso, Miikka; Simonen, Pauli; Ahlberg, Erik; Svenningsson, Birgitta; Brune, William Henry; Hillamo, Risto; Keskinen, Jorma; Rönkkö, Topi

    2016-07-01

    Changes in vehicle emission reduction technologies significantly affect traffic-related emissions in urban areas. In many densely populated areas the amount of traffic is increasing, keeping the emission level high or even increasing. To understand the health effects of traffic-related emissions, both primary (direct) particulate emission and secondary particle formation (from gaseous precursors in the exhaust emissions) need to be characterized. In this study, we used a comprehensive set of measurements to characterize both primary and secondary particulate emissions of a Euro 5 level gasoline passenger car. Our aerosol particle study covers the whole process chain in emission formation, from the tailpipe to the atmosphere, and also takes into account differences in driving patterns. We observed that, in mass terms, the amount of secondary particles was 13 times higher than the amount of primary particles. The formation, composition, number and mass of secondary particles was significantly affected by driving patterns and engine conditions. The highest gaseous and particulate emissions were observed at the beginning of the test cycle when the performance of the engine and the catalyst was below optimal. The key parameter for secondary particle formation was the amount of gaseous hydrocarbons in primary emissions; however, also the primary particle population had an influence.

  16. A traumatic hepatic artery pseudoaneurysm and arterioportal fistula, with severe diarrhea as the first symptom

    PubMed Central

    Han, Ping; Yang, Lan; Huang, Xiao-Wei; Zhu, Xiu-Qin; Chen, Li; Wang, Nan; Li, Zhen; Tian, De-An; Qin, Hua

    2018-01-01

    Abstract Rationale: Hepaticarterioportal fistula (APF) is a rare cause of portal hypertension and gastrointestinal hemorrhage, and presents as abnormal communication between the hepatic artery and portal vein. Percutaneous liver biopsy is a main iatrogenic cause of AFP. However, non-iatrogenic, abdominal, trauma-related APF is rarely reported. Patient concerns: A 29-year-old man presenting with severe, watery diarrhea was transferred to our hospital, and his condition was suspected to be acute gastroenteritis because he ate expired food and suffered a penetrating abdominal stab wound 5 years ago. After admission, the patient suffered from hematemesis, hematochezia, ascites, anuria, and kidney failure, and he developed shock. Diagnoses: The patient was finally diagnosed as a traumatic hepatic artery pseudoaneurysm and APF. Interventions: This patient was treated with emergency transarterial embolization using coils. Since a secondary feeding vessel was exposed after the first embolization of the main feeding artery, a less-selective embolization was performed again. Outcomes: During the 6-month follow-up period, the patient remained asymptomatic. Lessons: A penetrating abdominal stab wound is a rare cause of hepatic APFs, and occasionally leads to portal hypertension, the medical history and physical examination are the most important cornerstones of clinical diagnosis. Interventional radiology is essential for the diagnosis and treatment of an APF. PMID:29443759

  17. Role and Effectiveness of Percutaneous Arterial Embolization in Hemodynamically Unstable Patients with Ruptured Splanchnic Artery Pseudoaneurysms

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dohan, Anthony, E-mail: anthony.dohan@lrb.aphp.fr; Eveno, Clarisse, E-mail: clarisse.eveno@lrb.aphp.fr; Dautry, Raphael, E-mail: raphael.dautry@lrb.aphp.fr

    PurposeTo assess the role and effectiveness of percutaneous arterial embolization (TAE) in patients with hemodynamic instability due to hypovolemic shock secondary to ruptured splanchnic artery pseudoaneurysms (SAPA).Materials and MethodsSeventeen patients (11 men, 6 women; mean age, 53 years) with hemodynamic instability (systolic blood pressure <90 mmHg) due to hypovolemic shock secondary to ruptured SAPA were treated by TAE. Clinical files, multidetector row computed tomography angiography, and angiographic examinations along with procedure details were reviewed.ResultsSeventeen SAPAs were present, predominantly located on gastroduodenal or pancreatic arteries (9/17; 53 %). Angiography showed extravasation of contrast medium from SAPA in 15/17 patients (88 %). Technical success rate ofmore » TAE was 100 %. TAE was performed using metallic coils in all patients (100 %), in association with gelatin sponge in 5/17 patients (29 %). TAE allowed controlling the bleeding and returning to normal hemodynamic status in 16/17 patients (94 %). In 1/17 patient (6 %), surgery was needed to definitively control the bleeding. The mortality and morbidity rate of TAE at 30 days were 0 and 12 %, respectively. Morbidity consisted in coil migration in 1/17 patient (6 %) and transient serum liver enzyme elevation in 1/17 patient (6 %).ConclusionTAE is an effective and safe treatment option for ruptured SAPA in hemodynamically unstable patients, with a success rate of 94 %. Our results suggest that TAE should be the favored option in patients with hemodynamic instability due to ruptured SAPA.« less

  18. Multiple Renal Artery Pseudoaneurysms in Patients Undergoing Renal Artery Embolization Following Partial Nephrectomy: Correlation with RENAL Nephrometry Scores

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gupta, Nakul; Patel, Anish; Ensor, Joe

    PurposeTo describe the incidence of multiple renal artery pseudoaneurysms (PSA) in patients referred for renal artery embolization following partial nephrectomy and to study its relationship to RENAL nephrometry scores.Materials and MethodsThe medical records of 25 patients referred for renal artery embolization after partial nephrectomy were retrospectively reviewed for the following parameters: size and number of tumors, RENAL nephrometry scores, angiographic abnormalities, technical and clinical outcomes, and estimated glomerular filtration rates (eGFRs) after embolization.ResultsTwenty-four patients had primary renal tumors, while 1 patient had a pancreatic tumor invading the kidney. Multiple tumors were resected in 4 patients. Most patients (92 %) were symptomatic,more » presenting with gross hematuria, flank pain, or both. Angiography revealed PSA with (n = 5) or without (n = 20) AV fistulae. Sixteen patients (64 %) had multiple PSA involving multiple renal vessels. Higher RENAL nephrometry scores were associated with an increasing likelihood of multiple PSA. Multiple vessels were embolized in 14 patients (56 %). Clinical success was achieved after one (n = 22) or two (n = 3) embolization sessions in all patients. Post-embolization eGFR values at different time points after embolization were not significantly different from the post-operative eGFR.ConclusionA majority of patients requiring renal artery embolization following partial nephrectomy have multiple pseudoaneurysms, often requiring selective embolization of multiple vessels. Higher RENAL nephrometry score is associated with an increasing likelihood of multiple pseudoaneurysms. We found transarterial embolization to be a safe and effective treatment option with no long-term adverse effect on renal function in all but one patient with a solitary kidney.« less

  19. Urban stress-induced biogenic VOC emissions impact secondary aerosol formation in Beijing

    NASA Astrophysics Data System (ADS)

    Ghirardo, A.; Xie, J.; Zheng, X.; Wang, Y.; Grote, R.; Block, K.; Wildt, J.; Mentel, T.; Kiendler-Scharr, A.; Hallquist, M.; Butterbach-Bahl, K.; Schnitzler, J.-P.

    2015-08-01

    Trees can significantly impact the urban air chemistry by the uptake and emission of reactive biogenic volatile organic compounds (BVOCs), which are involved in ozone and particle formation. Here we present the emission potentials of "constitutive" (cBVOCs) and "stress-induced" BVOCs (sBVOCs) from the dominant broadleaf woody plant species in the megacity of Beijing. Based on an inventory of BVOC emissions and the tree census, we assessed the potential impact of BVOCs on secondary particulate matter formation in 2005 and 2010, i.e., before and after realizing the large tree-planting program for the 2008 Olympic Games. We found that sBVOCs, such as fatty acid derivatives, benzenoids and sesquiterpenes, constituted a significant fraction (∼ 15 %) of the total annual BVOC emissions, and we estimated that the overall annual BVOC budget may have doubled from ∼ 3.6 × 109 g C year-1 in 2005 to ∼ 7.1 × 109 g C year-1 in 2010 due to the increase in urban greens, while at the same time, the emission of anthropogenic VOCs (AVOCs) could be lowered by 24 %. Based on our BVOC emission assessment, we estimated the biological impact on SOA mass formation in Beijing. Compared to AVOCs, the contribution of biogenic precursors (2-5 %) for secondary particulate matter in Beijing was low. However, sBVOCs can significantly contribute (∼ 40 %) to the formation of total secondary organic aerosol (SOA) from biogenic sources; apparently, their annual emission increased from 1.05 μg m-3 in 2005 to 2.05 μg m-3 in 2010. This study demonstrates that biogenic and, in particular, sBVOC emissions contribute to SOA formation in megacities. However, the main problems regarding air quality in Beijing still originate from anthropogenic activities. Nevertheless, the present survey suggests that in urban plantation programs, the selection of plant species with low cBVOC and sBVOC emission potentials have some possible beneficial effects on urban air quality.

  20. Examining the Use of Audience Response Systems in Secondary School Classrooms: A Formative Analysis

    ERIC Educational Resources Information Center

    Kay, Robin; LeSage, Ann; Knaack, Liesel

    2010-01-01

    To date, extensive research has been done on the use of Audience Response Systems (ARSs) in colleges and universities, but not in secondary school schools. The purpose of this study was to conduct a detailed formative analysis on the benefits, challenges, and use of ARSs from the perspective of 659 secondary school students. Key benefits reported…

  1. Public Health Impacts of Secondary Particulate Formation from Aromatic Hydrocarbons in Gasoline

    EPA Science Inventory

    Background: Aromatic hydrocarbons emitted from gasoline‐powered vehicles contribute to the formation of secondary organic aerosol (SOA), which increases the atmospheric mass concentration of fine particles (PM2.5). Here we estimate the public health burden associated w...

  2. Formation of secondary aerosols from gasoline vehicle exhaust when mixing with SO2

    NASA Astrophysics Data System (ADS)

    Liu, T.; Wang, X.; Hu, Q.; Deng, W.; Zhang, Y.; Ding, X.; Fu, X.; Bernard, F.; Zhang, Z.; Lü, S.; He, Q.; Bi, X.; Chen, J.; Sun, Y.; Yu, J.; Peng, P.; Sheng, G.; Fu, J.

    2016-01-01

    Sulfur dioxide (SO2) can enhance the formation of secondary aerosols from biogenic volatile organic compounds (VOCs), but its influence on secondary aerosol formation from anthropogenic VOCs, particularly complex mixtures like vehicle exhaust, remains uncertain. Gasoline vehicle exhaust (GVE) and SO2, a typical pollutant from coal burning, are directly co-introduced into a smog chamber, in this study, to investigate the formation of secondary organic aerosols (SOA) and sulfate aerosols through photooxidation. New particle formation was enhanced, while substantial sulfate was formed through the oxidation of SO2 in the presence of high concentration of SO2. Homogenous oxidation by OH radicals contributed a negligible fraction to the conversion of SO2 to sulfate, and instead the oxidation by stabilized Criegee intermediates (sCIs), formed from alkenes in the exhaust reacting with ozone, dominated the conversion of SO2. After 5 h of photochemical aging, GVE's SOA production factor revealed an increase by 60-200 % in the presence of high concentration of SO2. The increase could principally be attributed to acid-catalyzed SOA formation as evidenced by the strong positive linear correlation (R2 = 0.97) between the SOA production factor and in situ particle acidity calculated by the AIM-II model. A high-resolution time-of-flight aerosol mass spectrometer (HR-TOF-AMS) resolved OA's relatively lower oxygen-to-carbon (O : C) (0.44 ± 0.02) and higher hydrogen-to-carbon (H : C) (1.40 ± 0.03) molar ratios for the GVE / SO2 mixture, with a significantly lower estimated average carbon oxidation state (OSc) of -0.51 ± 0.06 than -0.19 ± 0.08 for GVE alone. The relative higher mass loading of OA in the experiments with SO2 might be a significant explanation for the lower SOA oxidation degree.

  3. Formation of secondary aerosols from gasoline vehicle exhausts when mixing with SO2

    NASA Astrophysics Data System (ADS)

    Liu, T.; Wang, X.; Hu, Q.; Deng, W.; Zhang, Y.; Ding, X.; Fu, X.; Bernard, F.; Zhang, Z.; Lü, S.; He, Q.; Bi, X.; Chen, J.; Sun, Y.; Yu, J.; Peng, P.; Sheng, G.; Fu, J.

    2015-09-01

    Sulfur dioxide (SO2) can enhance the formation of secondary aerosols from biogenic volatile organic compounds (VOCs), but its influence on secondary aerosol formation from anthropogenic VOCs, particularly complex mixtures like vehicle exhausts, is still poorly understood. Here we directly co-introduced gasoline vehicles exhausts (GVE) and SO2, a typical pollutant from coal burning, into a smog chamber to investigate the formation of secondary organic aerosols (SOA) and sulfate aerosols through photooxidation. In the presence of high concentration of SO2, new particle formation was enhanced while substantial sulfate was formed through the oxidation of SO2. The homogenous oxidation by OH radicals contributed a negligible fraction to the conversion of SO2 to sulfate, and instead the oxidation by stabilized Criegee intermediates (sCIs), formed from alkenes in the exhaust reacting with ozone, dominated the conversion of SO2. After 5 h of photochemical aging, GVE's SOA production factor revealed an increase by 60-200 % in the presence of high concentration of SO2. This increase could largely be attributed to acid-catalyzed SOA formation, which was evidenced by the strong positive linear correlation (R2 = 0.97) between the SOA production factor and in-situ particle acidity calculated by AIM-II model. A high-resolution time-of-flight aerosol mass spectrometer (HR-TOF-AMS) resolved OA's relatively lower oxygen-to-carbon (O : C) and higher hydrogen-to-carbon (H : C) molar ratios for the GVE/SO2 mixture, with a much lower estimated average carbon oxidation state (OSc) of -0.51 ± 0.06 than that of -0.19 ± 0.08 for GVE alone. The relative higher mass loading of OA in the experiments with SO2 might be the major reason for the lower oxidation degree of SOA.

  4. Successful Resection of a Growing Distal Medial Lenticulostriate Artery Pseudoaneurysm Presenting with Isolated Intraventricular Hemorrhage.

    PubMed

    Sato, Yosuke; Ando, Kazuhiro; Kawaguchi, Makoto; Kakinuma, Kenichi

    2017-10-01

    Distal medial lenticulostriate artery (LSA) aneurysms associated with isolated intraventricular hemorrhage (IVH) are extremely rare. We report a very rare case of the isolated IVH due to the rupture of the distal medial LSA pseudoaneurysm that was not visible at the initial angiography but later emerged and grew. A 61-year-old woman with a history of hypertension had sudden onset of severe headache and mild consciousness disturbance. The computed tomography scan revealed the IVH, but the initial angiographies showed no evidence of aneurysm. The follow-up magnetic resonance imaging revealed that an intraventricular mass, arising from the right distal medial LSA, emerged and grew into the right anterior horn. Considering the risk of rebleeding, we resected the mass lesion via the transsulcal transventricular approach. The postoperative imaging showed complete obliteration of the mass lesion. Histopathological analysis indicated the pseudoaneurysm. The patient was discharged without any neurological deficit. The careful and repetitive follow-up imaging should be done in the cases with isolated IVH even if the initial image evaluations are unrevealing. The transsulcal transventricular approach can be the most minimally invasive surgical option for intraventricular lesion. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  5. Does three-dimensional transesophageal echocardiography provide incremental value in percutaneous closure of ascending aortic pseudoaneurysm?

    PubMed

    Elkaryoni, Ahmed; Hsiung, Ming C; Arisha, Mohammed J; Ahmad, Amier; Nanda, Navin C; Mohamed, Ahmed H; Attia, Doaa; Sachdeva, Ankush; Singh, Lovepreet; Yin, Wei-Hsian

    2017-07-01

    Ascending aortic pseudoaneurysms (AO PSAs), if left untreated, are complicated by a high rate of rupture resulting in significant morbidity and mortality. New transcatheter modalities have emerged as acceptable surgical alternatives for their management. We present a case of an ascending aortic PSA in which intraoperative two- and three-dimensional transesophageal echocardiography (2DTEE and 3DTEE) provided a comprehensive assessment of the PSA in pre- and postclosure settings. © 2017, Wiley Periodicals, Inc.

  6. Influence of Aerosol Acidity on the Formation of Secondary Organic Aerosol from Biogenic Precursor Hydrocarbons

    EPA Science Inventory

    Secondary organic aerosol (SOA) formation and dynamics may be important factors for the role of aerosols in adverse health effects, visibility and climate change. Formation of SOA occurs when a parent volatile organic compound is oxidized to create products that form in a conden...

  7. Secondary organic aerosol formation from road vehicle emissions

    NASA Astrophysics Data System (ADS)

    Pieber, Simone M.; Platt, Stephen M.; El Haddad, Imad; Zardini, Alessandro A.; Suarez-Bertoa, Ricardo; Slowik, Jay G.; Huang, Ru-Jin; Hellebust, Stig; Temime-Roussel, Brice; Marchand, Nicolas; Drinovec, Luca; Mocnik, Grisa; Baltensperger, Urs; Astorga, Covadogna; Prévôt, André S. H.

    2014-05-01

    Organic aerosol particles (OA) are a major fraction of the submicron particulate matter. OA consists of directly emitted primary (POA) and secondary OA (SOA). SOA is formed in-situ in the atmosphere via the reaction of volatile organic precursors. The partitioning of SOA species depends not only on the exposure to oxidants, but for instance also on temperature, relative humidity (RH), and the absorptive mass chemical composition (presence of inorganics) and concentration. Vehicle exhaust is a known source of POA and likely contributes to SOA formation in urban areas [1;2]. This has recently been estimated by (i) analyzing ambient data from urban areas combined with fuel consumption data [3], (ii) by examining the chemical composition of raw fuels [4], or (iii) smog chamber studies [5, 6]. Contradictory and thus somewhat controversial results in the relative quantity of SOA from diesel vs. gasoline vehicle exhaust were observed. In order to elucidate the impact of variable ambient conditions on the potential SOA formation of vehicle exhaust, and its relation to the emitted gas phase species, we studied SOA formed from the exhaust of passenger cars and trucks as a function of fuel and engine type (gasoline, diesel) at different temperatures (T 22 vs. -7oC) and RH (40 vs. 90%), as well as with different levels of inorganic salt concentrations. The exhaust was sampled at the tailpipe during regulatory driving cycles on chassis dynamometers, diluted (200 - 400x) and introduced into the PSI mobile smog chamber [6], where the emissions were subjected to simulated atmospheric ageing. Particle phase instruments (HR-ToF-AMS, aethalometers, CPC, SMPS) and gas phase instruments (PTR-TOF-MS, CO, CO2, CH4, THC, NH3 and other gases) were used online during the experiments. We found that gasoline emissions, because of cold starts, were generally larger than diesel, especially during cold temperatures driving cycles. Gasoline vehicles also showed the highest SOA formation

  8. Formation of hydroxyl radicals from photolysis of secondary organic aerosol material

    NASA Astrophysics Data System (ADS)

    Badali, K. M.; Zhou, S.; Aljawhary, D.; Antiñolo, M.; Chen, W. J.; Lok, A.; Mungall, E.; Wong, J. P. S.; Zhao, R.; Abbatt, J. P. D.

    2015-07-01

    This paper demonstrates that OH radicals are formed by photolysis of secondary organic aerosol (SOA) material formed by terpene ozonolysis. The SOA is collected on filters, dissolved in water containing a radical trap (benzoic acid), and then exposed to ultraviolet light in a photochemical reactor. The OH formation rates, which are similar for both α-pinene and limonene SOA, are measured from the formation rate of p-hydroxybenzoic acid as measured using offline HPLC analysis. To evaluate whether the OH is formed by photolysis of H2O2 or organic hydroperoxides (ROOH), the peroxide content of the SOA was measured using the horseradish peroxidase-dichlorofluorescein (HRP-DCF) assay, which was calibrated using H2O2. The OH formation rates from SOA are 5 times faster than from the photolysis of H2O2 solutions whose concentrations correspond to the peroxide content of the SOA solutions, assuming that the HRP-DCF signal arises from H2O2 alone. The higher rates of OH formation from SOA are likely due to ROOH photolysis, but we cannot rule out a contribution from secondary processes as well. This result is substantiated by photolysis experiments conducted with t-butyl hydroperoxide and cumene hydroperoxide which produce over 3 times more OH than photolysis of equivalent concentrations of H2O2. Relative to the peroxide level in the SOA and assuming that the peroxides drive most of the ultraviolet absorption, the quantum yield for OH generation from α-pinene SOA is 0.8 ± 0.4. This is the first demonstration of an efficient photolytic source of OH in SOA, one that may affect both cloud water and aerosol chemistry.

  9. Exact calculation of loop formation probability identifies folding motifs in RNA secondary structures

    PubMed Central

    Sloma, Michael F.; Mathews, David H.

    2016-01-01

    RNA secondary structure prediction is widely used to analyze RNA sequences. In an RNA partition function calculation, free energy nearest neighbor parameters are used in a dynamic programming algorithm to estimate statistical properties of the secondary structure ensemble. Previously, partition functions have largely been used to estimate the probability that a given pair of nucleotides form a base pair, the conditional stacking probability, the accessibility to binding of a continuous stretch of nucleotides, or a representative sample of RNA structures. Here it is demonstrated that an RNA partition function can also be used to calculate the exact probability of formation of hairpin loops, internal loops, bulge loops, or multibranch loops at a given position. This calculation can also be used to estimate the probability of formation of specific helices. Benchmarking on a set of RNA sequences with known secondary structures indicated that loops that were calculated to be more probable were more likely to be present in the known structure than less probable loops. Furthermore, highly probable loops are more likely to be in the known structure than the set of loops predicted in the lowest free energy structures. PMID:27852924

  10. Sequential Formation and Accumulation of Primary and Secondary Shunt Metabolic Products in Claviceps purpurea1

    PubMed Central

    Taber, W. A.

    1964-01-01

    The fungus Claviceps purpurea was grown on a rich and a limited nutrient medium such that alkaloid was produced after 8 days on the former medium and after 3 days on the latter medium. Cultures grown on both were assayed for the primary shunt metabolic products, polyols, trehalose, lipids, ribonucleic acid, and polyphosphate, and the secondary metabolic product, ergot alkaloid. Although differing considerably in composition, the two media nevertheless allowed formation of both primary and secondary shunt products. In both instances, however, the secondary product, ergot alkaloid, did not form until formation and accumulation of the primary products had ceased and the mycelial content of these products was actually decreasing. In both instances, alkaloid formation took place after the total dry weight of the mycelium had begun to decrease but while the dry weight of the residual, or structural portion of the mycelium, was either constant or increasing. The dilution of labeling in mannitol isolated from mycelia grown on rich medium containing 1,6-C14-labeled mannitol was 2.2. Thus, about half of the mycelial mannitol was actually mannitol which had been taken up directly from the medium. PMID:14199021

  11. Effect of ammonia on ozone-initiated formation of indoor secondary products with emissions from cleaning products

    NASA Astrophysics Data System (ADS)

    Huang, Yu; Lee, Shun Cheng; Ho, Kin Fai; Ho, Steven Sai Hang; Cao, Nanying; Cheng, Yan; Gao, Yuan

    2012-11-01

    Biogenic volatile organic compounds (BVOCs) emitted from cleaning products and air fresheners indoors are prone to oxidation resulting in the formation of secondary pollutants that can pose health risks on residents. Ammonia (NH3) is ubiquitous in ambient and indoor environments. In this study, we investigated the effect of ammonia (NH3) on secondary pollutants formation from the ozonolysis of BVOCs emitted from cleaning products including floor cleaner (FC), kitchen cleaner (KC) and dishwashing detergent (DD) in a large environmental chamber. Our results demonstrated that the presence of NH3 (maximum concentration is 240 ppb) could significantly enhance secondary organic aerosols (SOAs) formation from the ozonolysis of all the three categories of cleaning products. For example, for the FC sample, the maximum total particle concentration was up to 2.0 × 104 # cm-3 in the presence of NH3, while it was 1.3 × 104 # cm-3 which was 35% lower without NH3. However, it was found that the extent of NH3 effect on SOAs formation from the ozonolysis of BVOCs emissions was component-dependent. The presence of NH3 in the reaction systems could increase the consumptions of d-limonene that is the dominant BVOC species as identified in cleaning products. The percent yields (%) of secondary carbonyl compounds generated from the ozonolysis of BVOCs emitted from three categories of cleaning products were identified in the presence and absence of NH3, respectively. The increase in SOAs particle number concentration can be attributed to the formation of condensable salts from reactions between NH3 and organic compounds generated from the BVOCs ozonolysis processes. By investigating the NH3 effect on the ozonolysis of BVOCs mixtures in contrast to the chemistry of individual compounds, a better assessment can be made of the overall impact cleaning products have on real indoor environments.

  12. Secondary formation of disinfection by-products by UV treatment of swimming pool water.

    PubMed

    Spiliotopoulou, Aikaterini; Hansen, Kamilla M S; Andersen, Henrik R

    2015-07-01

    Formation of disinfection by-products (DBPs) during experimental UV treatment of pool water has previously been reported with little concurrence between laboratory studies, field studies and research groups. In the current study, changes in concentration of seven out of eleven investigated volatile DBPs were observed in experiments using medium pressure UV treatment, with and without chlorine and after post-UV chlorination. Results showed that post-UV chlorine consumption increased, dose-dependently, with UV treatment dose. A clear absence of trihalomethane formation by UV and UV with chlorine was observed, while small yet statistically significant increases in dichloroacetonitrile and dichloropropanone concentrations were detected. Results indicate that post-UV chlorination clearly induced secondary formation of several DBPs. However, the formation of total trihalomethanes was no greater than what could be replicated by performing the DBP formation assay with higher chlorine concentrations to simulate extended chlorination. Post-UV chlorination of water from a swimming pool that continuously uses UV treatment to control combined chlorine could not induce secondary formation for most DBPs. Concurrence for induction of trihalomethanes was identified between post-UV chlorination treatments and simulated extended chlorination time treatment. Trihalomethanes could not be induced by UV treatment of water from a continuously UV treated pool. This indicates that literature reports of experimentally induced trihalomethane formation by UV may be a result of kinetic increase in formation by UV. However, this does not imply that higher trihalomethane concentrations would occur in pools that apply continuous UV treatment. The bromine fraction of halogens in formed trihalomethanes increased with UV dose. This indicates that UV removes bromine atoms from larger molecules that participate in trihalomethane production during post-UV chlorination. Additionally, no significant

  13. Exact calculation of loop formation probability identifies folding motifs in RNA secondary structures.

    PubMed

    Sloma, Michael F; Mathews, David H

    2016-12-01

    RNA secondary structure prediction is widely used to analyze RNA sequences. In an RNA partition function calculation, free energy nearest neighbor parameters are used in a dynamic programming algorithm to estimate statistical properties of the secondary structure ensemble. Previously, partition functions have largely been used to estimate the probability that a given pair of nucleotides form a base pair, the conditional stacking probability, the accessibility to binding of a continuous stretch of nucleotides, or a representative sample of RNA structures. Here it is demonstrated that an RNA partition function can also be used to calculate the exact probability of formation of hairpin loops, internal loops, bulge loops, or multibranch loops at a given position. This calculation can also be used to estimate the probability of formation of specific helices. Benchmarking on a set of RNA sequences with known secondary structures indicated that loops that were calculated to be more probable were more likely to be present in the known structure than less probable loops. Furthermore, highly probable loops are more likely to be in the known structure than the set of loops predicted in the lowest free energy structures. © 2016 Sloma and Mathews; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

  14. Using THEMIS thermal infrared observations of rays from Corinto crater to study secondary crater formation on Mars

    NASA Astrophysics Data System (ADS)

    Williams, J. P.

    2017-12-01

    Corinto crater (16.95°N, 141.72°E), a 13.8 km diameter crater in Elysium Planitia, displays dramatic rays in Mars Odyssey's Thermal Emission Imaging System (THEMIS) nighttime infrared imagery where high concentrations of secondary craters have altered the thermophysical properties of the martian surface. The THEMIS observations provide a record of secondary crater formation in the region and ray segments are identified up to 2000 km ( 145 crater radii) distance [1][2]. Secondary craters are likely to have the largest influence on model surfaces ages between 0.1 to a few Myr as there is the potential for one or two sizeable craters to project secondary craters onto those surfaces and thus alter the crater size-frequency distribution (CSFD) with an instantaneous spike in crater production [3]. Corinto crater is estimated to be less than a few Ma [4] placing the formation of its secondaries within this formative time period. Secondary craters superposed on relatively young impact craters that predate Corinto provide observations of the secondary crater populations. Crater counts at 520 and 660 km distance from Corinto (38 and 48 crater radii respectively), were conducted. Higher crater densities were observed within ray segments, however secondary craters still influenced the CSFD where ray segments were not apparent, resulting in steepening in the CSFD. Randomness analysis confirms an increase in clustering as diameters decrease suggesting an increasing fraction of secondary craters at smaller diameters, both within the ray and outside. The counts demonstrate that even at nearly 50 crater radii, Corinto secondaries still influence the observed CSFD, even outside of any obvious rays. Crater populations used to derive model ages on many geologically young regions on Mars, such as glacial and periglacial landforms related to obliquity excursions that occur on 106 - 107 yr cycles, should be used cautiously and analyzed for any evidence, either morphologic or

  15. Primary sources and secondary formation of organic aerosols in Beijing, China.

    PubMed

    Guo, Song; Hu, Min; Guo, Qingfeng; Zhang, Xin; Zheng, Mei; Zheng, Jun; Chang, Chih Chung; Schauer, James J; Zhang, Renyi

    2012-09-18

    Ambient aerosol samples were collected at an urban site and an upwind rural site of Beijing during the CAREBEIJING-2008 (Campaigns of Air quality REsearch in BEIJING and surrounding region) summer field campaign. Contributions of primary particles and secondary organic aerosols (SOA) were estimated by chemical mass balance (CMB) modeling and tracer-yield method. The apportioned primary and secondary sources explain 73.8% ± 9.7% and 79.6% ± 10.1% of the measured OC at the urban and rural sites, respectively. Secondary organic carbon (SOC) contributes to 32.5 ± 15.9% of the organic carbon (OC) at the urban site, with 17.4 ± 7.6% from toluene, 9.7 ± 5.4% from isoprene, 5.1 ± 2.0% from α-pinene, and 2.3 ± 1.7% from β-caryophyllene. At the rural site, the secondary sources are responsible for 38.4 ± 14.4% of the OC, with the contributions of 17.3 ± 6.9%, 13.9 ± 9.1%, 5.6 ± 1.9%, and 1.7 ± 1.0% from toluene, isoprene, α-pinene, and β-caryophyllene, respectively. Compared with other regions in the world, SOA in Beijing is less aged, but the concentrations are much higher; between the sites, SOA is more aged and affected by regional transport at the urban site. The high SOA loading in Beijing is probably attributed to the high regional SOC background (~2 μg m(-3)). The toluene SOC concentration is high and comparable at the two sites, implying that some anthropogenic components, at least toluene SOA, are widespread in Beijing and represents a major factor in affecting the regional air quality. The aerosol gaseous precursor concentrations and temperature correlate well with SOA, both affecting SOA formation. The significant SOA enhancement with increasing water uptake and acidification indicates that the aqueous-phase reactions are largely responsible SOA formation in Beijing.

  16. Endovascular Stent Graft Placement in the Treatment of Ruptured Tuberculous Pseudoaneurysm of the Descending Thoracic Aorta: Case Report and Review of the Literature

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dogan, Sozen, E-mail: sozendogan@hotmail.com; Memis, Ahmet, E-mail: ahmemis@yahoo.co; Kale, Arzum, E-mail: arzumkale@kenthospital.com

    We report a successful repair of a ruptured tuberculous pseudoaneurysm of the descending thoracic aorta by endovascular stent graft placement. This procedure is starting to be accepted as an alternative method to surgery, and we review similar cases in the literature.

  17. Increasing Gas Hydrate Formation Temperature for Desalination of High Salinity Produced Water with Secondary Guests

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cha, Jong-Ho; Seol, Yongkoo

    We suggest a new gas hydrate-based desalination process using water-immiscible hydrate formers; cyclopentane (CP) and cyclohexane (CH) as secondary hydrate guests to alleviate temperature requirements for hydrate formation. The hydrate formation reactions were carried out in an isobaric condition of 3.1 MPa to find the upper temperature limit of CO2 hydrate formation. Simulated produced water (8.95 wt % salinity) mixed with the hydrate formers shows an increased upper temperature limit from -2 °C for simple CO2 hydrate to 16 and 7 °C for double (CO2 + CP) and (CO2 + CH) hydrates, respectively. The resulting conversion rate to double hydratemore » turned out to be similar to that with simple CO2 hydrate at the upper temperature limit. Hydrate formation rates (Rf) for the double hydrates with CP and CH are shown to be 22 and 16 times higher, respectively, than that of the simple CO2 hydrate at the upper temperature limit. Such mild hydrate formation temperature and fast formation kinetics indicate increased energy efficiency of the double hydrate system for the desalination process. Dissociated water from the hydrates shows greater than 90% salt removal efficiency for the hydrates with the secondary guests, which is also improved from about 70% salt removal efficiency for the simple hydrates.« less

  18. Dynamics of protein aggregation and oligomer formation governed by secondary nucleation

    NASA Astrophysics Data System (ADS)

    Michaels, Thomas C. T.; Lazell, Hamish W.; Arosio, Paolo; Knowles, Tuomas P. J.

    2015-08-01

    The formation of aggregates in many protein systems can be significantly accelerated by secondary nucleation, a process where existing assemblies catalyse the nucleation of new species. In particular, secondary nucleation has emerged as a central process controlling the proliferation of many filamentous protein structures, including molecular species related to diseases such as sickle cell anemia and a range of neurodegenerative conditions. Increasing evidence suggests that the physical size of protein filaments plays a key role in determining their potential for deleterious interactions with living cells, with smaller aggregates of misfolded proteins, oligomers, being particularly toxic. It is thus crucial to progress towards an understanding of the factors that control the sizes of protein aggregates. However, the influence of secondary nucleation on the time evolution of aggregate size distributions has been challenging to quantify. This difficulty originates in large part from the fact that secondary nucleation couples the dynamics of species distant in size space. Here, we approach this problem by presenting an analytical treatment of the master equation describing the growth kinetics of linear protein structures proliferating through secondary nucleation and provide closed-form expressions for the temporal evolution of the resulting aggregate size distribution. We show how the availability of analytical solutions for the full filament distribution allows us to identify the key physical parameters that control the sizes of growing protein filaments. Furthermore, we use these results to probe the dynamics of the populations of small oligomeric species as they are formed through secondary nucleation and discuss the implications of our work for understanding the factors that promote or curtail the production of these species with a potentially high deleterious biological activity.

  19. Dynamics of protein aggregation and oligomer formation governed by secondary nucleation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Michaels, Thomas C. T., E-mail: tctm3@cam.ac.uk; Lazell, Hamish W.; Arosio, Paolo

    2015-08-07

    The formation of aggregates in many protein systems can be significantly accelerated by secondary nucleation, a process where existing assemblies catalyse the nucleation of new species. In particular, secondary nucleation has emerged as a central process controlling the proliferation of many filamentous protein structures, including molecular species related to diseases such as sickle cell anemia and a range of neurodegenerative conditions. Increasing evidence suggests that the physical size of protein filaments plays a key role in determining their potential for deleterious interactions with living cells, with smaller aggregates of misfolded proteins, oligomers, being particularly toxic. It is thus crucial tomore » progress towards an understanding of the factors that control the sizes of protein aggregates. However, the influence of secondary nucleation on the time evolution of aggregate size distributions has been challenging to quantify. This difficulty originates in large part from the fact that secondary nucleation couples the dynamics of species distant in size space. Here, we approach this problem by presenting an analytical treatment of the master equation describing the growth kinetics of linear protein structures proliferating through secondary nucleation and provide closed-form expressions for the temporal evolution of the resulting aggregate size distribution. We show how the availability of analytical solutions for the full filament distribution allows us to identify the key physical parameters that control the sizes of growing protein filaments. Furthermore, we use these results to probe the dynamics of the populations of small oligomeric species as they are formed through secondary nucleation and discuss the implications of our work for understanding the factors that promote or curtail the production of these species with a potentially high deleterious biological activity.« less

  20. Variability in the primary emissions and secondary gas and particle formation from vehicles using bioethanol mixtures.

    PubMed

    Gramsch, E; Papapostolou, V; Reyes, F; Vásquez, Y; Castillo, M; Oyola, P; López, G; Cádiz, A; Ferguson, S; Wolfson, M; Lawrence, J; Koutrakis, P

    2018-04-01

    Bioethanol for use in vehicles is becoming a substantial part of global energy infrastructure because it is renewable and some emissions are reduced. Carbon monoxide (CO) emissions and total hydrocarbons (THC) are reduced, but there is still controversy regarding emissions of nitrogen oxides (NO x ), aldehydes, and ethanol; this may be a concern because all these compounds are precursors of ozone and secondary organic aerosol (SOA). The amount of emissions depends on the ethanol content, but it also may depend on the engine quality and ethanol origin. Thus, a photochemical chamber was used to study secondary gas and aerosol formation from two flex-fueled vehicles using different ethanol blends in gasoline. One vehicle and the fuel used were made in the United States, and the others were made in Brazil. Primary emissions of THC, CO, carbon dioxide (CO 2 ), and nonmethane hydrocarbons (NMHC) from both vehicles decreased as the amount of ethanol in gasoline increased. NO x emissions in the U.S. and Brazilian cars decreased with ethanol content. However, emissions of THC, CO, and NO x from the Brazilian car were markedly higher than those from the U.S. car, showing high variability between vehicle technologies. In the Brazilian car, formation of secondary nitrogen dioxide (NO 2 ) and ozone (O 3 ) was lower for higher ethanol content in the fuel. In the U.S. car, NO 2 and O 3 had a small increase. Secondary particle (particulate matter [PM]) formation in the chamber decreased for both vehicles as the fraction of ethanol in fuel increased, consistent with previous studies. Secondary to primary PM ratios for pure gasoline is 11, also consistent with previous studies. In addition, the time required to form secondary PM is longer for higher ethanol blends. These results indicate that using higher ethanol blends may have a positive impact on air quality. The use of bioethanol can significantly reduce petroleum use and greenhouse gas emissions worldwide. Given the extent of

  1. Endovascular Management of Infected Femoral Artery Pseudoaneurysms in High-Risk Patients: A Case Series

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    D’Oria, Mario, E-mail: mario.doria88@outlook.com; Sgorlon, Giada; Calvagna, Cristiano

    We report our experience with the urgent treatment of two high-risk patients with infected femoral artery pseudoaneurysms (IFAPs) with the placement of a self-expandable covered stent (SECS). In both cases, there was no perioperative mortality and the aneurysm exclusion was successful without early or late stent thrombosis/stent fracture nor acute or chronic limb ischemia or limb loss. There was no recurrence of local or systemic infection during the follow-up period. Endovascular therapy represents a feasible treatment option for IFAPs in those patients for whom the risk of open surgical repair would be prohibitive, especially under urgent circumstances.

  2. Cystic artery pseudoaneurysm presenting as a complication of laparoscopic cholecystectomy treated with percutaneous thrombin injection.

    PubMed

    Kumar, Abhishek; Sheikh, Ahmed; Partyka, Luke; Contractor, Sohail

    2014-01-01

    A 45-year-old woman status post laparoscopic cholecystectomy 3years ago presented with upper gastrointestinal bleeding. Endoscopy revealed hemobilia. Computed tomographic abdomen demonstrated a 2-cm aneurysm in the gall bladder fossa, consistent with a pseudoaneurysm. Initially, transcatheter coil embolization was attempted but recanalization of the aneurysm with recurrent bleeding in 2 days ensued. The aneurysm was then accessed percutaneously under ultrasound guidance and thrombin was injected into the aneurysm with subsequent complete thrombosis of the aneurysm and cessation of bleeding. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Emerging Trends in the Volume and Format of Outside Examinations Submitted for Secondary Interpretation

    PubMed Central

    Hunt, Christopher H.; Wood, Christopher P.; Diehn, Felix E.; Eckel, Laurence J.; Schwartz, Kara M.; Erickson, Bradley J.

    2014-01-01

    OBJECTIVE The purpose of this article is to describe the trends of secondary interpretations, including the total volume and format of cases. MATERIALS AND METHODS This retrospective study involved all outside neuroradiology examinations submitted for secondary interpretation from November 2006 through December 2010. This practice utilizes consistent criteria and includes all images that cover the brain, neck, and spine. For each month, the total number of outside examinations and their format (i.e., hard-copy film, DICOM CD-ROM, or non-DICOM CD-ROM) were recorded. RESULTS There was no significant change in the volume of cases (1043 ± 131 cases/month; p = 0.46, two-sided Student t test). There was a significant decrease in the volume of hard-copy films submitted, with the mean number of examinations submitted per month on hard-copy film declining from 297 in 2007 to 57 in 2010 (p < 0.0001, Student t test). This decrease was mirrored by an increase in the mean number of cases submitted on CD-ROM (753 cases/month in 2007 and 1036 cases/month in 2010; p < 0.0001). Although most were submitted in DICOM format, there was almost a doubling of the volume of cases submitted on non-DICOM CD-ROM (mean number of non-DICOM CD-ROMs, nine cases/month in 2007 and 17 cases/month in 2010; p < 0.001). CONCLUSION There has been a significant decrease in the number of hard-copy films submitted for secondary interpretation. There has been almost a doubling of the volume of cases submitted in non-DICOM formats, which is unfortunate, given the many advantages of the internationally derived DICOM standard, including ease of archiving, standardized display, efficient review, improved interpretation, and quality of patient care. PMID:22451538

  4. Emerging trends in the volume and format of outside examinations submitted for secondary interpretation.

    PubMed

    Hunt, Christopher H; Wood, Christopher P; Diehn, Felix E; Eckel, Laurence J; Schwartz, Kara M; Erickson, Bradley J

    2012-04-01

    The purpose of this article is to describe the trends of secondary interpretations, including the total volume and format of cases. This retrospective study involved all outside neuroradiology examinations submitted for secondary interpretation from November 2006 through December 2010. This practice utilizes consistent criteria and includes all images that cover the brain, neck, and spine. For each month, the total number of outside examinations and their format (i.e., hard-copy film, DICOM CD-ROM, or non-DICOM CD-ROM) were recorded. There was no significant change in the volume of cases (1043 ± 131 cases/month; p = 0.46, two-sided Student t test). There was a significant decrease in the volume of hard-copy films submitted, with the mean number of examinations submitted per month on hard-copy film declining from 297 in 2007 to 57 in 2010 (p < 0.0001, Student t test). This decrease was mirrored by an increase in the mean number of cases submitted on CD-ROM (753 cases/month in 2007 and 1036 cases/month in 2010; p < 0.0001). Although most were submitted in DICOM format, there was almost a doubling of the volume of cases submitted on non-DICOM CD-ROM (mean number of non-DICOM CD-ROMs, nine cases/month in 2007 and 17 cases/month in 2010; p < 0.001). There has been a significant decrease in the number of hard-copy films submitted for secondary interpretation. There has been almost a doubling of the volume of cases submitted in non-DICOM formats, which is unfortunate, given the many advantages of the internationally derived DICOM standard, including ease of archiving, standardized display, efficient review, improved interpretation, and quality of patient care.

  5. Preparation and characterization of injectable fibrillar type I collagen and evaluation for pseudoaneurysm treatment in a pig model.

    PubMed

    Geutjes, Paul J; van der Vliet, J Adam; Faraj, Kaeuis A; de Vries, Noes; van Moerkerk, Herman T B; Wismans, Ronnie G; Hendriks, Thijs; Daamen, Willeke F; van Kuppevelt, Toin H

    2010-11-01

    Despite the efficacy of collagen in femoral artery pseudoaneurysm treatment, as reported in one patient study, its use has not yet gained wide acceptance in clinical practice. In this particular study, the collagen was not described in detail. To further investigate the potential of collagen preparations, we prepared and characterized highly purified injectable fibrillar type I collagen and evaluated its use for femoral artery pseudoaneurysm (PSA) treatment in vivo using a pig model. Purified fibrillar type I collagen was characterized using electron microscopy. The effect of three different sterilization procedures, ie, hydrogen peroxide gas plasma (H2O2), ethylene oxide gas (EtO), and gamma irradiation, was studied on both SDS-PAGE and platelet aggregation. Different collagen injectables were prepared (3%, 4%, and 5%) and tested using an injection force test applying a 21-gauge needle. To evaluate the network characteristics of the injectable collagen, the collagen was suspended in phosphate buffered saline (PBS) at 37°C and studied both macroscopically and electron microscopically. To determine whether the collagen induced hemostasis in vivo, a pig PSA model was used applying a 4% EtO sterilized collagen injectable, and evaluation by angiography and routine histology. Electron microscopy of the purified type I collagen revealed intact fibrils with a distinct striated pattern and a length<300 μm. Both SDS-PAGE and platelet aggregation analysis of the sterilized collagen indicated no major differences between EtO and H2O2 sterilization, although gamma-irradiated collagen showed degradation products. Both 3% and 4% (w/v) collagen suspensions were acceptable with respect to the force used (<50 N). The 4% suspension was selected as the preferred injectable collagen, which formed a dense network under physiologic conditions. Testing the collagen in vivo (n=5), the angiograms revealed that the PSA partly or completely coagulated. Histology confirmed the network

  6. MRSA-infected external iliac artery pseudoaneurysm treated with endovascular stenting.

    PubMed

    Clarke, M G; Thomas, H G; Chester, J F

    2005-01-01

    A 48-year-old woman with severe juvenile-onset rheumatoid arthritis presented with a bleeding cutaneous sinus distal to her right total hip replacement scar. Methicillin resistant Staphylococcus aureus (MRSA) was isolated on culture. She had previously undergone bilateral total hip and knee replacements at aged 23 and six years later had the right knee prosthesis removed for infection, with subsequent osteomyelitis of the femoral shaft and right total hip prosthesis disruption. Peripheral arteriography was performed in view of persistent bleeding from the sinus, which revealed a 6 cm false aneurysm filling from and compressing the right external iliac artery (EIA). A PTFE-covered, balloon expandable JOSTENT was deployed in the right EIA, successfully excluding the false aneurysm and preventing further bleeding from the sinus. No graft infection was reported at 12 months. This case illustrates the potential use of endovascular stent-grafting in the treatment of an infected pseudoaneurysm.

  7. Cloud processing of organic compounds: Secondary organic aerosol and nitrosamine formation

    NASA Astrophysics Data System (ADS)

    Hutchings, James W., III

    Cloud processing of atmospheric organic compounds has been investigated through field studies, laboratory experiments, and numerical modeling. Observational cloud chemistry studies were performed in northern Arizona and fog studies in central Pennsylvania. At both locations, the cloud and fogs showed low acidity due to neutralization by soil dust components (Arizona) and ammonia (Pennsylvania). The field observations showed substantial concentrations (20-5500 ng•L -1) of volatile organic compounds (VOC) in the cloud droplets. The potential generation of secondary organic aerosol mass through the processing of these anthropogenic VOCs was investigated through laboratory and modeling studies. Under simulated atmospheric conditions, in idealized solutions, benzene, toluene, ethylbenzene, and xylene (BTEX) degraded quickly in the aqueous phase with half lives of approximately three hours. The degradation process yielded less volatile products which would contribute to new aerosol mass upon cloud evaporation. However, when realistic cloud solutions containing natural organic matter were used in the experiments, the reaction kinetics decreased with increasing organic carbon content, resulting in half lives of approximately 7 hours. The secondary organic aerosol (SUA) mass formation potential of cloud processing of BTEX was evaluated. SOA mass formation by cloud processing of BTEX, while strongly dependent on the atmospheric conditions, could contribute up to 9% of the ambient atmospheric aerosol mass, although typically ˜1% appears realistic. Field observations also showed the occurrence of N-nitrosodimethylamine (NDMA), a potent carcinogen, in fogs and clouds (100-340 ng•L -1). Laboratory studies were conducted to investigate the formation of NDMA from nitrous acid and dimethylamine in the homogeneous aqueous phase within cloud droplets. While NDMA was produced in the cloud droplets, the low yields (<1%) observed could not explain observational concentrations

  8. Reducing secondary organic aerosol formation from gasoline vehicle exhaust

    PubMed Central

    Zhao, Yunliang; Saleh, Rawad; Presto, Albert A.; Gordon, Timothy D.; Drozd, Greg T.; Goldstein, Allen H.; Robinson, Allen L.

    2017-01-01

    On-road gasoline vehicles are a major source of secondary organic aerosol (SOA) in urban areas. We investigated SOA formation by oxidizing dilute, ambient-level exhaust concentrations from a fleet of on-road gasoline vehicles in a smog chamber. We measured less SOA formation from newer vehicles meeting more stringent emissions standards. This suggests that the natural replacement of older vehicles with newer ones that meet more stringent emissions standards should reduce SOA levels in urban environments. However, SOA production depends on both precursor concentrations (emissions) and atmospheric chemistry (SOA yields). We found a strongly nonlinear relationship between SOA formation and the ratio of nonmethane organic gas to oxides of nitrogen (NOx) (NMOG:NOx), which affects the fate of peroxy radicals. For example, changing the NMOG:NOx from 4 to 10 ppbC/ppbNOx increased the SOA yield from dilute gasoline vehicle exhaust by a factor of 8. We investigated the implications of this relationship for the Los Angeles area. Although organic gas emissions from gasoline vehicles in Los Angeles are expected to fall by almost 80% over the next two decades, we predict no reduction in SOA production from these emissions due to the effects of rising NMOG:NOx on SOA yields. This highlights the importance of integrated emission control policies for NOx and organic gases. PMID:28630318

  9. Emergency Stent Grafting After Unsuccessful Surgical Repair of a Mycotic Common Femoral Artery Pseudoaneurysm in a Drug Abuser

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lupattelli, Tommaso, E-mail: tommaso.lupattelli@multimedica.i; Garaci, Francesco Giuseppe; Basile, Antonio

    Mycotic false aneurysm caused by local arterial injury from attempted intravenous injections in drug addicts remains a challenging clinical problem. The continued increase in drug abuse has resulted in an increased incidence of this problem, particularly in high-volume urban centres. In the drug-abusing population, mycotic arterial pseudoaneurysms most often occur because of missed venous injection and are typically seen in the groin, axilla, and antecubital fossa. Mycotic aneurysms may lead to life-threatening haemorrhage, limb loss, sepsis, and even death. Any soft-tissue swelling in the vicinity of a major artery in an intravenous drug abuser should be suspected of being amore » false aneurysm until proven otherwise and should prompt immediate referral to a vascular surgeon for investigation and management. We report a case of rupturing mycotic pseudoaneurysm of the left common femoral artery treated by surgical resection followed by vessel reconstruction with autologous material. Unfortunately, at the time of discharge a sudden leakage from the vein graft anastomosis occurred, with subsequent massive bleeding, and required emergent endovascular covered stenting. To the best of our knowledge, this is the first reported case of femoral artery bleeding in a drug abuser treated by stent graft placement.« less

  10. Evaluation of arteriovenous fistulas and pseudoaneurysms in renal allografts following percutaneous needle biopsy. Color-coded Doppler sonography versus duplex Doppler sonography.

    PubMed

    Hübsch, P J; Mostbeck, G; Barton, P P; Gritzmann, N; Fruehwald, F X; Schurawitzki, H; Kovarik, J

    1990-02-01

    One hundred one patients with renal allografts were studied by two independent observers using duplex Doppler sonography (DDS) and color-coded Doppler sonography (CCDS). In all patients, single or multiple percutaneous needle biopsies of the transplant had been performed 1 to 30 days before. In 6 patients CCDS following the biopsy demonstrated an area of combined red and blue color-coded blood flow within the renal parenchyma (n = 5) or within the sinus (n = 1); the Doppler waveform was abnormal in these areas with signals above and below the zero line indicating turbulent blood flow. Consecutive intraarterial digital subtraction angiography (DSA) revealed the presence of an arteriovenous fistula (n = 4) or of a pseudoaneurysm (n = 2). In one patient, gross hematuria with obstruction of the bladder occurred as a complication of a pseudoaneurysm within the renal sinus; the bleeding could not be stopped by embolization of the lesion and the kidney had to be removed. DDS demonstrated the lesion in only one of the six patients. Thus, CCDS is the method of choice for noninvasive detection of vascular lesions due to percutaneous biopsy.

  11. [Pseudoaneurysm in the vicinity of the ascending aorta caused by contained disruption at the insertion site of a coronary artery bypass graft. A case report].

    PubMed

    Drögemüller, A; Zahn, R; Bergmeier, C; Werling, C; Isgro, F; Senges, J

    1998-08-01

    In this case report a 65-year-old patient came into the emergency ward with acute chest pain after coronary artery bypass graft operation in 1985. On routine chest X-ray in 1995 a mediastinal widening was diagnosed. The chest X-ray in 1997 (Figure 1) showed an increase of the diameter of the known mediastinal widening. Therefore a CT-scan was performed (Figures 2a and 2b). This showed an enhancement of contrast material in a contained structure, without identifying its origin. Therefore a coronary angiography was done. Here, we diagnosed a contained disruption of the aorta at the insertion site of the bypass graft at the right coronary artery. Figure 3a shows leakage of contrast material out of the aorta into the pseudoaneurysm and in Figure 3b this is demonstrated in a schematic drawing. Figure 4a shows supraselective imaging of the pseudoaneurysm, demonstrated in a schematic drawing in Figure 4b. As the chest pain could only be handled by i.v.-medication, betablocker and bed rest we decided to operate. Intra-operatively the diagnosis was confirmed (Figure 5a and 5b). Postoperatively the patient died due to cerebral ischemia. Despite the lethal outcome an operative revision appears even retrospectively justified because of the increasing size of the pseudoaneurysm in addition to new symptoms that were difficult to treat. On the other hand there are no data available in order to estimate the risk of a spontaneous course.

  12. Formation mechanism of the secondary building unit in a chromium terephthalate metal-organic framework

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cantu Cantu, David; McGrail, B. Peter; Glezakou, Vassiliki Alexandra

    2014-09-18

    Based on density functional theory calculations and simulation, a detailed mechanism is presented on the formation of the secondary building unit (SBU) of MIL-101, a chromium terephthalate metal-organic framework (MOF). SBU formation is key to MOF nucleation, the rate-limiting step in the formation process of many MOFs. A series of reactions that lead to the formation of the SBU of MIL-101 is proposed in this work. Initial rate-limiting reactions form the metal cluster with three chromium (III) atoms linked to a central bridging oxygen. Terephthalate linkers play a key role as chromium (III) atoms are joined to linker carboxylate groupsmore » prior to the placement of the central bridging oxygen. Multiple linker addition reactions, which follow in different paths due to structural isomers, are limited by the removal of water molecules in the first chromium coordination shell. The least energy path is identified were all linkers on one face of the metal center plane are added first. A simple kinetic model based on transition state theory shows the rate of secondary building unit formation similar to the rate metal-organic framework nucleation. The authors are thankful to Dr. R. Rousseau for a critical reading of the manuscript. This research would not have been possible without the support of the Office of Fossil Energy, U.S. Department of Energy. This research was performed using EMSL, a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and the PNNL Institutional Computing (PIC) program located at Pacific Northwest National Laboratory.« less

  13. Lithologic Control on Secondary Clay Mineral Formation in the Valles Caldera, New Mexico

    NASA Astrophysics Data System (ADS)

    Caylor, E.; Rasmussen, C.; Dhakal, P.

    2015-12-01

    Understanding the transformation of rock to soil is central to landscape evolution and ecosystem function. The objective of this study was to examine controls on secondary mineral formation in a forested catchment in the Catalina-Jemez CZO. We hypothesized landscape position controls the type of secondary minerals formed in that well-drained hillslopes favor Si-poor secondary phases such as kaolinite, whereas poorly drained portions of the landscape that collect solutes from surrounding areas favor formation of Si-rich secondary phases such as smectite. The study focused on a catchment in Valles Caldera in northern New Mexico where soils are derived from a mix of rhyolitic volcanic material, vegetation includes a mixed conifer forest, and climate is characterized by a mean annual precipitation of ~800 mm yr-1 and mean annual temperature of 4.5°C. Soils were collected at the soil-saprolite boundary from three landscape positions, classified as well drained hillslope, poorly drained convergent area, and poorly drained hill slope. Clay fractions were isolated and analyzed using a combination of quantitative and qualitative x-ray diffraction (XRD) analyses and thermal analysis. Quantitative XRD of random powder mounts indicated the presence of both primary phases such as quartz, and alkali and plagioclase feldspars, and secondary phases that include illite, Fe-oxyhydroxides including both goethite and hematite, kaolinite, and smectite. The clay fractions were dominated by smectite ranging from 36-42%, illite ranging from 21-35%, and kaolinite ranging from 1-8%. Qualitative XRD of oriented mounts confirmed the presence of smectite in all samples, with varying degrees of interlayering and interstratification. In contrast to our hypothesis, results indicated that secondary mineral assemblage was not strongly controlled by landscape position, but rather varied with underlying variation in lithology. The catchment is underlain by a combination of porphorytic rhyolite and

  14. The formation of science choices in secondary school

    NASA Astrophysics Data System (ADS)

    Cleaves, Anna

    2005-04-01

    In this paper I examine the formation of post-16 choices over 3 years among higher achieving students with respect to enrolment in post-compulsory science courses. Transcripts from four interviews carried out over 3 years with 72 secondary school students were qualitatively analysed. Students were found to shape their choices for science in a variety of ways across time. The situation regarding science choices hinges on far more dynamic considerations than the stereotypical image of the potential advanced science student, committed to becoming a scientist from an early age. There is an interplay of self-perception with respect to science, occupational images of working scientists, relationship with significant adults and perceptions of school science The findings are informative for science educators and for career guidance professionals who may need to take into account the complexity of young people's choices.

  15. Impacts of raindrop evaporative cooling on tropical cyclone secondary eyewall formation

    NASA Astrophysics Data System (ADS)

    Ge, Xuyang; Guan, Liang; Yan, Ziyu

    2018-06-01

    The impacts of raindrop evaporative cooling on secondary eyewall formation (SEF) of simulated tropical cyclones are investigated using idealized numerical experiments. The results suggest that the raindrop evaporative cooling effect is beneficial to the development of secondary eyewall through the planetary boundary layer (PBL) cold pool process. The evaporative cooling-driven downdrafts bring about the surface cold pool beneath a precipitation cloud. This cold pool dynamics act as a lifting mechanism to trigger the outer convection. The radially outward propagation of spiral rainbands broadens the TC size, by which modifies the surface heat fluxes and thus outer convection. Furthermore, the unbalanced PBL process contributes to the SEF. The radially outward surface outflows forces convection at outer region and thus favors a larger TC size. A larger TC implies an enhanced inertial stability at the outer region, which favors a higher conversion efficiency of diabatic heating to kinetic energy.

  16. MRSA-Infected External Iliac Artery Pseudoaneurysm Treated with Endovascular Stenting

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Clarke, M.G.; Thomas, H.G.; Chester, J.F.

    2005-04-15

    A 48-year-old woman with severe juvenile-onset rheumatoid arthritis presented with a bleeding cutaneous sinus distal to her right total hip replacement scar. Methicillin resistant Staphylococcus aureus (MRSA) was isolated on culture. She had previously undergone bilateral total hip and knee replacements at aged 23 and six years later had the right knee prosthesis removed for infection, with subsequent osteomyelitis of the femoral shaft and right total hip prosthesis disruption. Peripheral arteriography was performed in view of persistent bleeding from the sinus, which revealed a 6 cm false aneurysm filling from and compressing the right external iliac artery (EIA). A PTFE-covered,more » balloon expandable JOSTENT was deployed in the right EIA, successfully excluding the false aneurysm and preventing further bleeding from the sinus. No graft infection was reported at 12 months. This case illustrates the potential use of endovascular stent-grafting in the treatment of an infected pseudoaneurysm.« less

  17. Venous pseudoaneurysm of the great saphenous vein stump as late complication of flush saphenofemoral ligation and stripping.

    PubMed

    Domanin, Maurizio; Miloro, Riccardo; Romagnoli, Silvia; Basellini, Aldo

    2018-03-01

    Guidelines now recommend endovenous thermal ablation over open treatment of saphenous incompetence, but flush saphenofemoral ligation and stripping remain relevant when appropriately applied and expertly executed. Complications are rare but could be severe, needing further surgical correction. We report a unique case of a late venous pseudoaneurysm of the great saphenous vein stump after flush saphenofemoral ligation and stripping, successfully treated with surgical sac excision. We highlight the importance of continuous follow-up for patients previously submitted to open venous surgery.

  18. Secondary organic aerosol formation from isoprene photooxidation

    NASA Astrophysics Data System (ADS)

    Kroll, J. H.; Ng, N. L.; Murphy, S. M.; Flagan, R. C.; Seinfeld, J. H.

    2005-12-01

    We report chamber studies of the formation of secondary organic aerosol (SOA) from the oxidation of isoprene (2-methyl-1,3-butadiene). Isoprene is the most abundant non-methane hydrocarbon emitted into the troposphere (source strength of ~500 Tg/year), so even small SOA yields may have a large impact on global SOA production. Reactions are carried out in Caltech's dual 28 m3 Teflon chambers, and aerosol growth is monitored by a differential mobility analyzer (DMA) and an Aerodyne time-of-flight aerosol mass spectrometer (AMS). Isoprene oxidation is initiated by the UV irradiation of isoprene in the presence of hydrogen peroxide, with NO added for high-NOx experiments. These conditions ensure that isoprene oxidation is initiated by reaction with the OH radical, with negligible interference from other oxidants (ozone, nitrate radicals, and O atoms). Aerosol growth is observed under both high-NOx and low-NOx conditions, at isoprene concentrations lower than measured in previous studies (down to 8 ppb). SOA yields are found to be in the range of 1-2%. Yields exhibit a complex dependence on NOx concentration, likely a result of changes in the chemistry of organic peroxy radicals. It is shown that condensable compounds are formed from further reactions of first-generation isoprene oxidation products; the rates and products of such gas-phase reactions are at present poorly understood. Additionally, measurements of SOA composition indicate that these products undergo reactions in the aerosol phase, leading to the formation of low-volatility oligomeric products.

  19. Secondary organic aerosols - formation and ageing studies in the SAPHIR chamber

    NASA Astrophysics Data System (ADS)

    Spindler, Christian; Müller, Lars; Trimborn, Achim; Mentel, Thomas; Hoffmann, Thorsten

    2010-05-01

    Secondary organic aerosol (SOA) formation from oxidation products of biogenic volatile organic compounds (BVOC) constitutes an important coupling between vegetation, atmospheric chemistry, and climate change. Such secondary organic aerosol components play an important role in particle formation in Boreal regions ((Laaksonen et al., 2008)), where biogenic secondary organic aerosols contribute to an overall negative radiative forcing, thus a negative feed back between vegetation and climate warming (Spracklen et al., 2008). Within the EUCAARI project we investigated SOA formation from mixtures of monoterpenes (and sesquiterpenes) as emitted typically from Boreal tree species in Southern Finland. The experiments were performed in the large photochemical reactor SAPHIR in Juelich at natural light and oxidant levels. Oxidation of the BVOC mixtures and SOA formation was induced by OH radicals and O3. The SOA was formed on the first day and then aged for another day. The resulting SOA was characterized by HR-ToF-AMS, APCI-MS, and filter samples with subsequent H-NMR, GC-MS and HPLC-MS analysis. The chemical evolution of the SOA is characterized by a fast increase of the O/C ratio during the formation process on the first day, stable O/C ratio during night, and a distinctive increase of O/C ratio at the second day. The increase of the O/C ratio on the second day is highly correlated to the OH dose and is accompanied by condensational growth of the particles. We will present simultaneous factor analysis of AMS times series (PMF, Ulbrich et al., 2009 ) and direct measurements of individual chemical species. We found that four factors were needed to represent the time evolution of the SOA composition (in the mass spectra) if oxidation by OH plays a mayor role. Corresponding to these factors we observed individual, representative molecules with very similar time behaviour. The correlation between tracers and AMS factors is astonishingly good as the molecular tracers

  20. Secondary ion formation during electronic and nuclear sputtering of germanium

    NASA Astrophysics Data System (ADS)

    Breuer, L.; Ernst, P.; Herder, M.; Meinerzhagen, F.; Bender, M.; Severin, D.; Wucher, A.

    2018-06-01

    Using a time-of-flight mass spectrometer attached to the UNILAC beamline located at the GSI Helmholtz Centre for Heavy Ion Research, we investigate the formation of secondary ions sputtered from a germanium surface under irradiation by swift heavy ions (SHI) such as 5 MeV/u Au by simultaneously recording the mass spectra of the ejected secondary ions and their neutral counterparts. In these experiments, the sputtered neutral material is post-ionized via single photon absorption from a pulsed, intensive VUV laser. After post-ionization, the instrument cannot distinguish between secondary ions and post-ionized neutrals, so that both signals can be directly compared in order to investigate the ionization probability of different sputtered species. In order to facilitate an in-situ comparison with typical nuclear sputtering conditions, the system is also equipped with a conventional rare gas ion source delivering a 5 keV argon ion beam. For a dynamically sputter cleaned surface, it is found that the ionization probability of Ge atoms and Gen clusters ejected under electronic sputtering conditions is by more than an order of magnitude higher than that measured for keV sputtered particles. In addition, the mass spectra obtained under SHI irradiation show prominent signals of GenOm clusters, which are predominantly detected as positive or negative secondary ions. From the m-distribution for a given Ge nuclearity n, one can deduce that the sputtered material must originate from a germanium oxide matrix with approximate GeO stoichiometry, probably due to residual native oxide patches even at the dynamically cleaned surface. The results clearly demonstrate a fundamental difference between the ejection and ionization mechanisms in both cases, which is interpreted in terms of corresponding model calculations.

  1. Formation of secondary minerals in a lysimeter approach - A mineral-microbe interaction

    NASA Astrophysics Data System (ADS)

    Schäffner, F.; Merten, D.; De Giudici, G.; Beyer, A.; Akob, D. M.; Ricci, P. C.; Küsel, K.; Büchel, G.

    2012-04-01

    Heavy metal contamination of large areas due to uranium mining operations poses a serious long-term environmental problem. In the Ronneburg district (eastern Thuringia, Germany), leaching of low grade uranium bearing ores (uranium content < 300 g/t) occurred from 1972 to 1990 using acid mine drainage (AMD; pH 2.7-2.8) and diluted sulphuric acid (10 g/l). Secondary mineral phases like birnessite, todorokite and goethite occur within a natural attenuation process associated with enrichment of heavy metals, especially Cd, Ni, Co, Cu and Zn due to a residual contamination even after remediation efforts. To reveal the processes of secondary mineral precipitation in the field a laboratory lysimeter approach was set up under in situ-like conditions. Homogenized soil from the field site and pure quartz sand were used as substrates. In general, in situ measurements of redox potentials in the substrates showed highly oxidizing conditions (200-750 mV). Water was supplied to the lysimeter from below via a mariottés bottle containing contaminated groundwater from the field. Evaporation processes were allowed, providing a continuous flow of water. This led to precipitation of epsomite and probably aplowite on the top layer of substrate, similar to what is observed in field investigations. After 4 weeks, the first iron and manganese bearing secondary minerals became visible. Soil water samples were used to monitor the behaviour of metals within the lysimeter. Saturation indices (SI) for different secondary minerals were calculated with PHREEQC. The SI of goethite showed oversaturation with respect to the soil solution. SEM-EDX analyses and IR spectroscopy confirmed the formation of goethite. Geochemical data revealed that goethite formation was mainly dominated by Eh/pH processes and that heavy metals, e.g. Zn and U, could be enriched in this phase. Although Eh/pH data does not support formation of manganese minerals, Mn(II)-oxidizing bacteria (MOB) could be isolated from field

  2. [Estimate of the formation potential of secondary organic aerosol in Beijing summertime].

    PubMed

    Lü, Zi-Feng; Hao, Ji-Ming; Duan, Jing-Chun; Li, Jun-Hua

    2009-04-15

    Fractional aerosol coefficients (FAC) are used in conjunction with measurements of volatile organic compounds (VOC) during ozone episodes to estimate the formation potential of secondary organic aerosols (SOA) in the summertime of Beijing. The estimation is based on the actual atmospheric conditions of Beijing, and benzene and isoprene are considered as the precursors of SOA. The results show that 31 out of 70 measured VOC species are SOA precursors, and the total potential SOA formation is predicted to be 8.48 microg/m3, which accounts for 30% of fine organic particle matter. Toluene, xylene, pinene, ethylbenzene and n-undecane are the 5 largest contributors to SOA production and account for 20%, 22%, 14%, 9% and 4% of total SOA production, respectively. The anthropogenic aromatic compounds, which yield 76% of the calculated SOA, are the major source of SOA. The biogenic alkenes, alkanes and carbonyls produce 16%, 7% and 1% of SOA formation, respectively. The major components of produced SOA are expected to be aromatic compounds, aliphatic acids, carbonyls and aliphatic nitrates, which contribute to 72%, 14%, 11% and 3% of SOA mass, respectively. The SOA precursors have relatively low atmospheric concentrations and low ozone formation potential. Hence, SOA formation potential of VOC species, in addition to their atmospheric concentrations and ozone formation potential, should be considered in policy making process of VOCs control.

  3. Influence of fuel ethanol content on primary emissions and secondary aerosol formation potential for a modern flex-fuel gasoline vehicle

    NASA Astrophysics Data System (ADS)

    Timonen, Hilkka; Karjalainen, Panu; Saukko, Erkka; Saarikoski, Sanna; Aakko-Saksa, Päivi; Simonen, Pauli; Murtonen, Timo; Dal Maso, Miikka; Kuuluvainen, Heino; Bloss, Matthew; Ahlberg, Erik; Svenningsson, Birgitta; Pagels, Joakim; Brune, William H.; Keskinen, Jorma; Worsnop, Douglas R.; Hillamo, Risto; Rönkkö, Topi

    2017-04-01

    The effect of fuel ethanol content (10, 85 and 100 %) on primary emissions and on subsequent secondary aerosol formation was investigated for a Euro 5 flex-fuel gasoline vehicle. Emissions were characterized during a New European Driving Cycle (NEDC) using a comprehensive set-up of high time-resolution instruments. A detailed chemical composition of the exhaust particulate matter (PM) was studied using a soot particle aerosol mass spectrometer (SP-AMS), and secondary aerosol formation was studied using a potential aerosol mass (PAM) chamber. For the primary gaseous compounds, an increase in total hydrocarbon emissions and a decrease in aromatic BTEX (benzene, toluene, ethylbenzene and xylenes) compounds was observed when the amount of ethanol in the fuel increased. In regard to particles, the largest primary particulate matter concentrations and potential for secondary particle formation was measured for the E10 fuel (10 % ethanol). As the ethanol content of the fuel increased, a significant decrease in the average primary particulate matter concentrations over the NEDC was found. The PM emissions were 0.45, 0.25 and 0.15 mg m-3 for E10, E85 and E100, respectively. Similarly, a clear decrease in secondary aerosol formation potential was observed with a larger contribution of ethanol in the fuel. The secondary-to-primary PM ratios were 13.4 and 1.5 for E10 and E85, respectively. For E100, a slight decrease in PM mass was observed after the PAM chamber, indicating that the PM produced by secondary aerosol formation was less than the PM lost through wall losses or the degradation of the primary organic aerosol (POA) in the chamber. For all fuel blends, the formed secondary aerosol consisted mostly of organic compounds. For E10, the contribution of organic compounds containing oxygen increased from 35 %, measured for primary organics, to 62 % after the PAM chamber. For E85, the contribution of organic compounds containing oxygen increased from 42 % (primary) to 57

  4. Organic Aerosol Formation Photoenhanced by the Formation of Secondary Photo-sensitizers in ageing Aerosols

    NASA Astrophysics Data System (ADS)

    Aregahegn, Kifle; Nozière, Barbara; George, Christian

    2013-04-01

    Humankind is facing a changing environment possibly due to anthropogenic stress on the atmosphere. In this context, aerosols play a key role by affecting the radiative climate forcing, hydrological cycle, and by their adverse effect on health. The role of organic compounds in these processes is however still poorly understood because of their massive chemical complexity and numerous transformations. This is particularly true for Secondary Organic Aerosol (SOA), which are produced in the atmosphere by organic gases. Traditionally, the driving forces for SOA growth is believed to be the partitioning onto aerosol seeds of condensable gases, either emitted primarily or resulting from the gas phase oxidation of organic gases. However, even the most up-to-date models based on such mechanisms can not account for the SOA mass observed in the atmosphere, suggesting the existence of other, yet unknown formation processes. The present study shows experimental evidence that particulate phase chemistry produces photo-sensitizers that lead to photo-induced formation and growth of secondary organic aerosol in the near UV and the presence of volatile organic compounds (VOC) such as terpenes. By means of an aerosol flow tube reactor equipped with Scanning Mobility Particle Sizer (SMPS) having Kr-85 source aerosol neutralizer, Differential Mobility Analyser (DMA) and Condensation Particle Sizer (CPC), we identified that traces of the aerosol phase product of glyoxal chemistry as is explained in Gallway et al., and Yu et al., namely imidazole-2-carboxaldehyde (IC) is a strong photo-sensitizer when irradiated by near-UV in the presence of volatile organic compounds such as terpenes. Furthermore, the influence of pH, type and concentration of VOCs, composition of seed particles, relative humidity and irradiation intensity on particle growth were studied. This novel photo-sensitizer contributed to more than 30% of SOA growth in 19min irradiation time in the presence of terpenes in the

  5. Flow-diverting Stent in the Treatment of Cervical Carotid Dissection and Pseudoaneurysm: Review of Literature and Case Report.

    PubMed

    Baptista-Sincos, Anna Paula Weinhardt; Simplício, Aline Bigatão; Sincos, Igor Rafael; Leaderman, Alex; Neto, Fernando Saliture; Moraes, Adjaldes; Aun, Ricardo

    2018-01-01

    The endovascular technique has been recommended over the past few years to extracranial carotid dissection and pseudoaneurysm with promising results, especially after medical therapy failure. Flow-diverting stents are an alternative for complex cases. These stents have proven to be effective treatment devices for intracranial aneurysms. The reference list of Pham's systematic review, published in 2011, and Seward's literature review, published in 2015, was considered, as well as all new articles with eligible features. Search was conducted on specific databases: MEDLINE and Literatura Latino-Americana e do Caribe em Ciências da Saúde. For carotid dissection and pseudoaneurysm, our review yielded 3 published articles including 12 patients. The technical success rate of flow-diverting stent was 100% with no procedural complication described. Mean clinical follow-up was 27.2 months (range 5-48), and in 5 months' angiographic follow-up, all lesions had healed. No new neurological events were reported during the clinical follow-up. Flow diverter stent use on intracranial and peripheral vascular surgery demonstrates satisfactory initial results, but it is still under investigation. There are very few cases treated till now and the initial results with flow-diverting stents to cervical carotid dissection are promising. In well-selected cases, where simple embolization or conventional stent is not appropriate, this technic may be considered. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Comparison of primary and secondary particle formation from natural gas engine exhaust and of their volatility characteristics

    NASA Astrophysics Data System (ADS)

    Alanen, Jenni; Simonen, Pauli; Saarikoski, Sanna; Timonen, Hilkka; Kangasniemi, Oskari; Saukko, Erkka; Hillamo, Risto; Lehtoranta, Kati; Murtonen, Timo; Vesala, Hannu; Keskinen, Jorma; Rönkkö, Topi

    2017-07-01

    Natural gas usage in the traffic and energy production sectors is a growing trend worldwide; thus, an assessment of its effects on air quality, human health and climate is required. Engine exhaust is a source of primary particulate emissions and secondary aerosol precursors, which both contribute to air quality and can cause adverse health effects. Technologies, such as cleaner engines or fuels, that produce less primary and secondary aerosols could potentially significantly decrease atmospheric particle concentrations and their adverse effects. In this study, we used a potential aerosol mass (PAM) chamber to investigate the secondary aerosol formation potential of natural gas engine exhaust. The PAM chamber was used with a constant UV-light voltage, which resulted in relatively long equivalent atmospheric ages of 11 days at most. The studied retro-fitted natural gas engine exhaust was observed to form secondary aerosol. The mass of the total aged particles, i.e., particle mass measured downstream of the PAM chamber, was 6-268 times as high as the mass of the emitted primary exhaust particles. The secondary organic aerosol (SOA) formation potential was measured to be 9-20 mg kgfuel-1. The total aged particles mainly consisted of organic matter, nitrate, sulfate and ammonium, with the fractions depending on exhaust after-treatment and the engine parameters used. Also, the volatility, composition and concentration of the total aged particles were found to depend on the engine operating mode, catalyst temperature and catalyst type. For example, a high catalyst temperature promoted the formation of sulfate particles, whereas a low catalyst temperature promoted nitrate formation. However, in particular, the concentration of nitrate needed a long time to stabilize - more than half an hour - which complicated the conclusions but also indicates the sensitivity of nitrate measurements on experimental parameters such as emission source and system temperatures. Sulfate was

  7. Impact of Propene on Secondary Organic Aerosol Formation from m-Xylene

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Song, Chen; Na, Kwangsam; Warren, Bethany

    2007-10-15

    Propene is widely used in smog chamber experiments to increase the hydroxyl radical (OH) level based on the assumption that the formation of secondary organic aerosol (SOA) from parent hydrocarbon is unaffected. A series ofm-xylene/NOx photooxidation experiments were conducted in the presence of propene in the University of California CECERT atmospheric chamber facility. The experimental data are compared with previousm-xylene/NOx photooxidation work performed in the same chamber facility in the absence of propene (Song et al. Environ. Sci. Technol. 2005, 39, 3143-3149). The result shows that, for similar initial conditions, experiments with propene have lower reaction rates of m-xylene thanmore » those without propene, which indicates that propene reduces OH in the system. Furthermore, experiments with propene showed more than 15% reduction in SOA yield compared to experiments in the absence of propene. Additional experiments ofm-xylene/NOx with CO showed similar trends of suppressing OH and SOA formation. These results indicate that SOA from m-xylene/NOx photooxidation is strongly dependent on the OH level present, which provides evidence for the critical role of OH in SOA formation from aromatic hydrocarbons.« less

  8. Secondary organic aerosol formation through cloud processing of aromatic VOCs

    NASA Astrophysics Data System (ADS)

    Herckes, P.; Hutchings, J. W.; Ervens, B.

    2010-12-01

    Field observations have shown substantial concentrations (20-5,500 ng L-1) of aromatic volatile organic compounds (VOC) in cloud droplets. The potential generation of secondary organic aerosol mass through the processing of these anthropogenic VOCs was investigated through laboratory and modeling studies. Under simulated atmospheric laboratory conditions, in idealized solutions, benzene, toluene, ethylbenzene, and xylene (BTEX) degraded quickly in the aqueous phase. The degradation process yielded less volatile products which would contribute to new aerosol mass upon cloud evaporation. However, when realistic cloud solutions containing natural organic matter were used in the experiments, the reaction rates decreased with increasing organic carbon content. Kinetic data derived from these experiments were used as input to a multiphase box model in order to evaluate the secondary organic aerosol (SOA) mass formation potential of cloud processing of BTEX. Model results will be presented that quantify the SOA amounts from these aqueous phase pathways. The efficiency of this multiphase SOA source will be compared to SOA yields from the same aromatics as treated in traditional SOA models that are restricted to gas phase oxidation and subsequent condensation on particles.

  9. Successful Embolization of a Renal Artery Pseudoaneurysm with Arteriovenous Fistula and Extravasations Using Onyx After Partial Nephrectomy for Renal Cell Carcinoma

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zelenak, Kamil, E-mail: zelenak@mfn.s; Sopilko, Igor; Svihra, Jan

    2009-01-15

    Partial nephrectomy can be associated with vascular complications. Computed tomography (CT) with CT angiography is ideal for noninvasive imaging of this process. The treatment of choice is selective embolization. Successful transcatheter embolization of right renal subsegmental artery pseudoaneurysm with arteriovenous fistula and extravasations using Onyx was performed in a 66-year-old woman with macrohematuria 12 days after partial nephrectomy for renal cell carcinoma.

  10. Contrasting Secondary Organic Aerosol Formation in Aerosol Liquid Water During Summer and Winter

    NASA Astrophysics Data System (ADS)

    El-Sayed, M.; Hennigan, C. J.

    2017-12-01

    In this study, we characterize the formation of aqueous secondary organic aerosols (aqSOA) in the eastern United States during summer and winter. The aim was to identify the main factors affecting the reversible and irreversible uptake of water-soluble organic gases to aerosol liquid water under variable influence from biogenic and anthropogenic sources. The reversible and irreversible uptake of water-soluble organic gases to aerosol water was measured in Baltimore, MD using a recently developed on-line method. The formation of aqSOA was observed during the summer and the winter; however, the amount of aqSOA varied significantly between the two seasons, as did the reversible and irreversible nature of the uptake. While the availability of aerosol liquid water (ALW) predominantly controlled aqSOA formation in the summer, wintertime aqSOA formation was limited by precursor VOCs as well. During the summer, aqSOA formation was tightly linked with isoprene oxidation, while the aqSOA formed in the winter was associated with biomass burning. Irreversible aqSOA was formed in both seasons; however, reversible aqSOA was only observed in the summer. Overall, these results demonstrate the importance of multi-phase chemistry in aerosol formation and underscore the significance of soluble organic gases partitioning to aerosol water both reversibly and irreversibly.

  11. Organic Nitrate Contribution to New Particle Formation and Growth in Secondary Organic Aerosols from α-Pinene Ozonolysis.

    PubMed

    Berkemeier, Thomas; Ammann, Markus; Mentel, Thomas F; Pöschl, Ulrich; Shiraiwa, Manabu

    2016-06-21

    The chemical kinetics of organic nitrate production during new particle formation and growth of secondary organic aerosols (SOA) were investigated using the short-lived radioactive tracer (13)N in flow-reactor studies of α-pinene oxidation with ozone. Direct and quantitative measurements of the nitrogen content indicate that organic nitrates accounted for ∼40% of SOA mass during initial particle formation, decreasing to ∼15% upon particle growth to the accumulation-mode size range (>100 nm). Experiments with OH scavengers and kinetic model results suggest that organic peroxy radicals formed by α-pinene reacting with secondary OH from ozonolysis are key intermediates in the organic nitrate formation process. The direct reaction of α-pinene with NO3 was found to be less important for particle-phase organic nitrate formation. The nitrogen content of SOA particles decreased slightly upon increase of relative humidity up to 80%. The experiments show a tight correlation between organic nitrate content and SOA particle-number concentrations, implying that the condensing organic nitrates are among the extremely low volatility organic compounds (ELVOC) that may play an important role in the nucleation and growth of atmospheric nanoparticles.

  12. Formation of secondary aerosols from the ozonolysis of styrene: Effect of SO2 and H2O

    NASA Astrophysics Data System (ADS)

    Díaz-de-Mera, Yolanda; Aranda, Alfonso; Martínez, Ernesto; Rodríguez, Ana Angustias; Rodríguez, Diana; Rodríguez, Ana

    2017-12-01

    In this work we report the study of the ozonolysis of styrene and the reaction conditions leading to the formation of secondary aerosols. The reactions have been carried out in a Teflon chamber filled with synthetic air mixtures at atmospheric pressure and room temperature. We have found that the ozonolysis of styrene in the presence of low concentrations of SO2 readily produces new particles under concentrations of reactants lower than those required in experiments in the absence of SO2. Thus, nucleation events occur at concentrations around (5.6 ± 1.7) × 108molecule cm-3 (errors are 2σ±20%) and SO2 is consumed during the experiments. The reaction of the Criegee intermediates with SO2 to produce SO3 and then H2SO4 may explain (together with OH reactions' contribution) the high capacity of styrene to produce particulate matter in polluted atmospheres. The formation of secondary aerosols in the smog chamber is inhibited under high H2O concentrations. So, the potential formation of secondary aerosols under atmospheric conditions depends on the concentration of SO2 and relative humidity, with a water to SO2 rate constants ratio kH2O/kSO2 = (2.8 ± 0.7) × 10-5 (errors are 2σ±20%).

  13. Secondary chaotic terrain formation in the higher outflow channels of southern circum-Chryse, Mars

    USGS Publications Warehouse

    Rodriguez, J.A.P.; Kargel, J.S.; Tanaka, K.L.; Crown, D.A.; Berman, D.C.; Fairen, A.G.; Baker, V.R.; Furfaro, R.; Candelaria, P.; Sasaki, S.

    2011-01-01

    Higher outflow channel dissection in the martian region of southern circum-Chryse appears to have extended from the Late Hesperian to the Middle Amazonian Epoch. These outflow channels were excavated within the upper 1. km of the cryolithosphere, where no liquid water is expected to have existed during these geologic epochs. In accordance with previous work, our examination of outflow channel floor morphologies suggests the upper crust excavated by the studied outflow channels consisted of a thin (a few tens of meters) layer of dry geologic materials overlying an indurated zone that extends to the bases of the investigated outflow channels (1. km in depth). We find that the floors of these outflow channels contain widespread secondary chaotic terrains (i.e., chaotic terrains produced by the destruction of channel-floor materials). These chaotic terrains occur within the full range of outflow channel dissection and tend to form clusters. Our examination of the geology of these chaotic terrains suggests that their formation did not result in the generation of floods. Nevertheless, despite their much smaller dimensions, these chaotic terrains are comprised of the same basic morphologic elements (e.g., mesas, knobs, and smooth deposits within scarp-bound depressions) as those located in the initiation zones of the outflow channels, which suggests that their formation must have involved the release of ground volatiles. We propose that these chaotic terrains developed not catastrophically but gradually and during multiple episodes of nested surface collapse. In order to explain the formation of secondary chaotic terrains within zones of outflow channel dissection, we propose that the regional Martian cryolithosphere contained widespread lenses of volatiles in liquid form. In this model, channel floor collapse and secondary chaotic terrain formation would have taken place as a consequence of instabilities arising during their exhumation by outflow channel dissection

  14. Molecular structure impacts on secondary organic aerosol formation from glycol ethers

    NASA Astrophysics Data System (ADS)

    Li, Lijie; Cocker, David R.

    2018-05-01

    Glycol ethers, a class of widely used solvents in consumer products, are often considered exempt as volatile organic compounds based on their vapor pressure or boiling points by regulatory agencies. However, recent studies found that glycol ethers volatilize at ambient conditions nearly as rapidly as the traditional high-volatility solvents indicating the potential of glycol ethers to form secondary organic aerosol (SOA). This is the first work on SOA formation from glycol ethers. The impact of molecular structure, specifically -OH, on SOA formation from glycol ethers and related ethers are investigated in the work. Ethers with and without -OH, with methyl group hindrance on -OH and with -OH at different location are studied in the presence of NOX and under "NOX free" conditions. Photooxidation experiments under different oxidation conditions confirm that the processing of ethers is a combination of carbonyl formation, cyclization and fragmentation. Bulk SOA chemical composition analysis and oxidation products identified in both gas and particle phase suggests that the presence and location of -OH in the carbon bond of ethers determine the occurrence of cyclization mechanism during ether oxidation. The cyclization is proposed as a critical SOA formation mechanism to prevent the formation of volatile compounds from fragmentation during the oxidation of ethers. Glycol ethers with -CH2-O-CH2CH2OH structure is found to readily form cyclization products, especially with the presence of NOx, which is more relevant to urban atmospheric conditions than without NOx. Glycol ethers are evaluated as dominating SOA precursors among all ethers studied. It is estimated that the contribution of glycol ethers to anthropogenic SOA is roughly 1% of the current organic aerosol from mobile sources. The contribution of glycol ethers to anthropogenic SOA is roughly 1% of the current organic aerosol from mobile sources and will play a more important role in future anthropogenic SOA

  15. The Treatment of Infected Femoral Artery Pseudoaneurysms Secondary to Drug Abuse: 11 Years of Experience at a Single Institution.

    PubMed

    Qiu, Jiehua; Zhou, Weimin; Zhou, Wei; Tang, Xinhua; Yuan, Qingwen; Zhu, Xianhua; Yang, Yujin; Xiong, Jixin

    2016-10-01

    The purpose of our study is to analyze the methods of treating infected femoral artery pseudoaneurysms (IFAPs), and also to identify the most appropriate method, especially for patients with a long history of drug abuse. A retrospective chart review of 88 consecutive IFAPs secondary to drug abuse between 2003 and 2014 was performed. Outpatient clinic charts were reviewed, as well as inpatient and anesthesia records. All patients had undergone a computer tomography angiography or contrast computer tomography to confirm their diagnosis. Routine blood tests were performed. The treatment methods included common femoral artery ligation (CFA) along with local debridement and drainage, direct oversewing, and amputation. A clamping test of the distal external iliac artery (EIA) or the common femoral artery was performed after vessel isolation, during which the oxygen saturation of the blood at the end of the affected limb was examined with a continuous pulse oximeter. Skin samples from affected limbs were tested with hematoxylin and eosin (HE) stain. There were a total of 88 patients, of which 79 and 9 came from emergency and outpatient, respectively. Acute hemorrhage at the injection site, pulsatile mass, septic syndrome, and necrosis were present in 65, 14, 8, and 1 patients, respectively. All patients experienced groin pain. Thigh or leg swelling was present in 63 patients. The drug injection history was a mean 6.9 ± 4.1 years. Seventy-four patients presented with anemia and 75 patients presented with hypoproteinemia. Hepatitis B, hepatitis C, syphilis, and HIV were found in 42, 57, 12, and 2 patients, respectively. One patient gave up the treatment. One patient was treated by amputation along with CFA ligation and local debridement because the limb was necrotic on admission. Three patients with short drug injection abuse history and local slight infection were treated by direct oversewing. Eighty-three patients, of which 27 had a drug injection history shorter than

  16. Formative Assessment and Increased Student Involvement Increase Grades in an Upper Secondary School Biology Course

    ERIC Educational Resources Information Center

    Granbom, Martin

    2016-01-01

    This study shows that formative methods and increased student participation has a positive influence on learning measured as grades. The study was conducted during the course Biology A in a Swedish Upper Secondary School. The students constructed grade criteria and defined working methods and type of examination within a given topic, Gene…

  17. Seed Regeneration Potential of Canopy Gaps at Early Formation Stage in Temperate Secondary Forests, Northeast China

    PubMed Central

    Yan, Qiao-Ling; Zhu, Jiao-Jun; Yu, Li-Zhong

    2012-01-01

    Promoting the seed regeneration potential of secondary forests undergoing gap disturbances is an important approach for achieving forest restoration and sustainable management. Seedling recruitment from seed banks strongly determines the seed regeneration potential, but the process is poorly understood in the gaps of secondary forests. The objectives of the present study were to evaluate the effects of gap size, seed availability, and environmental conditions on the seed regeneration potential in temperate secondary forests. It was found that gap formation could favor the invasion of more varieties of species in seed banks, but it also could speed up the turnover rate of seed banks leading to lower seed densities. Seeds of the dominant species, Fraxinus rhynchophylla, were transient in soil and there was a minor and discontinuous contribution of the seed bank to its seedling emergence. For Quercus mongolica, emerging seedling number was positively correlated with seed density in gaps (R = 0.32, P<0.01), especially in medium and small gaps (<500 m2). Furthermore, under canopies, there was a positive correlation between seedling number and seed density of Acer mono (R = 0.43, P<0.01). Gap formation could promote seedling emergence of two gap-dependent species (i.e., Q. mongolica and A. mono), but the contribution of seed banks to seedlings was below 10% after gap creation. Soil moisture and temperature were the restrictive factors controlling the seedling emergence from seeds in gaps and under canopies, respectively. Thus, the regeneration potential from seed banks is limited after gap formation. PMID:22745771

  18. Reactive intermediates revealed in secondary organic aerosol formation from isoprene

    PubMed Central

    Surratt, Jason D.; Chan, Arthur W. H.; Eddingsaas, Nathan C.; Chan, ManNin; Loza, Christine L.; Kwan, Alan J.; Hersey, Scott P.; Flagan, Richard C.; Wennberg, Paul O.; Seinfeld, John H.

    2010-01-01

    Isoprene is a significant source of atmospheric organic aerosol; however, the oxidation pathways that lead to secondary organic aerosol (SOA) have remained elusive. Here, we identify the role of two key reactive intermediates, epoxydiols of isoprene (IEPOX = β-IEPOX + δ-IEPOX) and methacryloylperoxynitrate (MPAN), which are formed during isoprene oxidation under low- and high-NOx conditions, respectively. Isoprene low-NOx SOA is enhanced in the presence of acidified sulfate seed aerosol (mass yield 28.6%) over that in the presence of neutral aerosol (mass yield 1.3%). Increased uptake of IEPOX by acid-catalyzed particle-phase reactions is shown to explain this enhancement. Under high-NOx conditions, isoprene SOA formation occurs through oxidation of its second-generation product, MPAN. The similarity of the composition of SOA formed from the photooxidation of MPAN to that formed from isoprene and methacrolein demonstrates the role of MPAN in the formation of isoprene high-NOx SOA. Reactions of IEPOX and MPAN in the presence of anthropogenic pollutants (i.e., acidic aerosol produced from the oxidation of SO2 and NO2, respectively) could be a substantial source of “missing urban SOA” not included in current atmospheric models. PMID:20080572

  19. Formation of wood secondary cell wall may involve two type cellulose synthase complexes in Populus.

    PubMed

    Xi, Wang; Song, Dongliang; Sun, Jiayan; Shen, Junhui; Li, Laigeng

    2017-03-01

    Cellulose biosynthesis is mediated by cellulose synthases (CesAs), which constitute into rosette-like cellulose synthase complexe (CSC) on the plasma membrane. Two types of CSCs in Arabidopsis are believed to be involved in cellulose synthesis in the primary cell wall and secondary cell walls, respectively. In this work, we found that the two type CSCs participated cellulose biosynthesis in differentiating xylem cells undergoing secondary cell wall thickening in Populus. During the cell wall thickening process, expression of one type CSC genes increased while expression of the other type CSC genes decreased. Suppression of different type CSC genes both affected the wall-thickening and disrupted the multilaminar structure of the secondary cell walls. When CesA7A was suppressed, crystalline cellulose content was reduced, which, however, showed an increase when CesA3D was suppressed. The CesA suppression also affected cellulose digestibility of the wood cell walls. The results suggest that two type CSCs are involved in coordinating the cellulose biosynthesis in formation of the multilaminar structure in Populus wood secondary cell walls.

  20. Modeling the relative contributions of secondary ice formation processes to ice crystal number concentrations within mixed-phase clouds

    NASA Astrophysics Data System (ADS)

    Sullivan, Sylvia; Hoose, Corinna; Nenes, Athanasios

    2016-04-01

    Measurements of in-cloud ice crystal number concentrations can be three or four orders of magnitude greater than the in-cloud ice nuclei number concentrations. This discrepancy can be explained by various secondary ice formation processes, which occur after initial ice nucleation, but the relative importance of these processes, and even the exact physics of each, is still unclear. A simple bin microphysics model (2IM) is constructed to investigate these knowledge gaps. 2IM extends the time-lag collision parameterization of Yano and Phillips, 2011 to include rime splintering, ice-ice aggregation, and droplet shattering and to incorporate the aspect ratio evolution as in Jensen and Harrington, 2015. The relative contribution of the secondary processes under various conditions are shown. In particular, temperature-dependent efficiencies are adjusted for ice-ice aggregation versus collision around -15°C, when rime splintering is no longer active, and the effect of aspect ratio on the process weighting is explored. The resulting simulations are intended to guide secondary ice formation parameterizations in larger-scale mixed-phase cloud schemes.

  1. Contribution of Glyoxal to Secondary Organic Aerosol Formation in Los Angeles

    NASA Astrophysics Data System (ADS)

    Washenfelder, R. A.; Young, C. J.; Brown, S. S.; Gilman, J. B.; Kuster, W. C.; de Gouw, J. A.

    2010-12-01

    Glyoxal (CHOCHO) is the simplest alpha-dicarbonyl and one of the most prevalent dicarbonyls in the atmosphere. It is an oxidation product of isoprene, and is also formed from the photooxidation of anthropogenic hydrocarbons, including aromatics and ethyne. In addition to its importance as a source of HOx, previous studies indicate that glyoxal reacts heterogeneously to form secondary organic aerosol. For the CalNex field campaign during summer 2010, we deployed a new glyoxal field instrument in Pasadena, California. This instrument consists of a broadband LED light source coupled to a cavity enhanced absorption spectrometer (IBBCEAS). The effective pathlength of the instrument is approximately 18 km. The measurement precision of the glyoxal instrument allows us to observe diurnal variability and trends. The glyoxal measurements were co-located with a comprehensive set of hydrocarbon measurements. These included the important photochemical precursors for CHOCHO, with measurements of isoprene, ethyne, ethene, monoterpenes, aromatics, and methylbutenol. We use the precursor concentrations to evaluate expected glyoxal concentrations. The difference between the expected gas-phase production of glyoxal and the measured concentrations indicates the contribution that glyoxal makes to secondary organic aerosol formation in Los Angeles.

  2. Axillary artery injury secondary to inferior shoulder dislocation.

    PubMed

    Plaga, Brad R; Looby, Peter; Feldhaus, Steven J; Kreutzmann, Karl; Babb, Aaron

    2010-11-01

    Dislocation injuries of the glenohumeral joint are common in the general public and generally are corrected without complication. One serious complication with shoulder dislocations, or the subsequent reduction, is a lesion to the axillary artery. This specific complication is most frequently seen in the elderly population, where vascular structures have become less flexible. Also, these injuries are most common in association with anterior dislocations of the shoulder. To bring awareness to the possibility of axillary artery injury with inferior dislocation of the shoulder, the treatment options, and a review. We report a 15-year-old male athlete who inferiorly dislocated his shoulder during wrestling practice. The injury was reduced at the scene with manual traction and the patient was transferred to our clinic for evaluation. The patient was determined to have a pseudoaneurysm of the axillary artery, and the history and treatment of the illness are presented. Axillary artery injuries secondary to shoulder dislocations are rare, especially in the young athlete, and proper recognition and treatment offer patients a full recovery. Copyright © 2010. Published by Elsevier Inc.

  3. FORMATION OF SECONDARY ORGANIC AEROSOL

    EPA Science Inventory

    (1) Gas-phase chemistry. With the clear and profound effect of the VOC/NOx ratio on SOA formation, we will augment gas-phase VOC oxidation mechanisms in atmospheric models to account for the effect of NOx level on the mechanism of SOA formation; (2) Revis...

  4. Formation of secondary organic aerosol coating on black carbon particles near vehicular emissions

    NASA Astrophysics Data System (ADS)

    Lee, Alex K. Y.; Chen, Chia-Li; Liu, Jun; Price, Derek J.; Betha, Raghu; Russell, Lynn M.; Zhang, Xiaolu; Cappa, Christopher D.

    2017-12-01

    Black carbon (BC) emitted from incomplete combustion can result in significant impacts on air quality and climate. Understanding the mixing state of ambient BC and the chemical characteristics of its associated coatings is particularly important to evaluate BC fate and environmental impacts. In this study, we investigate the formation of organic coatings on BC particles in an urban environment (Fontana, California) under hot and dry conditions using a soot-particle aerosol mass spectrometer (SP-AMS). The SP-AMS was operated in a configuration that can exclusively detect refractory BC (rBC) particles and their coatings. Using the -log(NOx / NOy) ratio as a proxy for photochemical age of air masses, substantial formation of secondary organic aerosol (SOA) coatings on rBC particles was observed due to active photochemistry in the afternoon, whereas primary organic aerosol (POA) components were strongly associated with rBC from fresh vehicular emissions in the morning rush hours. There is also evidence that cooking-related organic aerosols were externally mixed from rBC. Positive matrix factorization and elemental analysis illustrate that most of the observed SOA coatings were freshly formed, providing an opportunity to examine SOA coating formation on rBCs near vehicular emissions. Approximately 7-20 wt % of secondary organic and inorganic species were estimated to be internally mixed with rBC on average, implying that rBC is unlikely the major condensation sink of SOA in this study. Comparison of our results to a co-located standard high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) measurement suggests that at least a portion of SOA materials condensed on rBC surfaces were chemically different from oxygenated organic aerosol (OOA) particles that were externally mixed with rBC, although they could both be generated from local photochemistry.

  5. Different roles of water in secondary organic aerosol formation from toluene and isoprene

    NASA Astrophysics Data System (ADS)

    Jia, Long; Xu, YongFu

    2018-06-01

    Roles of water in the formation of secondary organic aerosol (SOA) from the irradiations of toluene-NO2 and isoprene-NO2 were investigated in a smog chamber. Experimental results show that the yield of SOA from toluene almost doubled as relative humidity increased from 5 to 85 %, whereas the yield of SOA from isoprene under humid conditions decreased by 2.6 times as compared to that under dry conditions. The distinct difference of RH effects on SOA formation from toluene and isoprene is well explained with our experiments and model simulations. The increased SOA from humid toluene-NO2 irradiations is mainly contributed by O-H-containing products such as polyalcohols formed from aqueous reactions. The major chemical components of SOA in isoprene-NO2 irradiations are oligomers formed from the gas phase. SOA formation from isoprene-NO2 irradiations is controlled by stable Criegee intermediates (SCIs) that are greatly influenced by water. As a result, high RH can obstruct the oligomerization reaction of SCIs to form SOA.

  6. Gasoline emissions dominate over diesel in formation of secondary organic aerosol mass

    NASA Astrophysics Data System (ADS)

    Bahreini, R.; Middlebrook, A. M.; de Gouw, J. A.; Warneke, C.; Trainer, M.; Brock, C. A.; Stark, H.; Brown, S. S.; Dube, W. P.; Gilman, J. B.; Hall, K.; Holloway, J. S.; Kuster, W. C.; Perring, A. E.; Prevot, A. S. H.; Schwarz, J. P.; Spackman, J. R.; Szidat, S.; Wagner, N. L.; Weber, R. J.; Zotter, P.; Parrish, D. D.

    2012-03-01

    Although laboratory experiments have shown that organic compounds in both gasoline fuel and diesel engine exhaust can form secondary organic aerosol (SOA), the fractional contribution from gasoline and diesel exhaust emissions to ambient SOA in urban environments is poorly known. Here we use airborne and ground-based measurements of organic aerosol (OA) in the Los Angeles (LA) Basin, California made during May and June 2010 to assess the amount of SOA formed from diesel emissions. Diesel emissions in the LA Basin vary between weekdays and weekends, with 54% lower diesel emissions on weekends. Despite this difference in source contributions, in air masses with similar degrees of photochemical processing, formation of OA is the same on weekends and weekdays, within the measurement uncertainties. This result indicates that the contribution from diesel emissions to SOA formation is zero within our uncertainties. Therefore, substantial reductions of SOA mass on local to global scales will be achieved by reducing gasoline vehicle emissions.

  7. Bacterial and iron oxide aggregates mediate secondary iron mineral formation: green rust versus magnetite.

    PubMed

    Zegeye, A; Mustin, C; Jorand, F

    2010-06-01

    In the presence of methanoate as electron donor, Shewanella putrefaciens, a Gram-negative, facultative anaerobe, is able to transform lepidocrocite (gamma-FeOOH) to secondary Fe (II-III) minerals such as carbonated green rust (GR1) and magnetite. When bacterial cells were added to a gamma-FeOOH suspension, aggregates were produced consisting of both bacteria and gamma-FeOOH particles. Recently, we showed that the production of secondary minerals (GR1 vs. magnetite) was dependent on bacterial cell density and not only on iron reduction rates. Thus, gamma-FeOOH and S. putrefaciens aggregation pattern was suggested as the main mechanism driving mineralization. In this study, lepidocrocite bioreduction experiments, in the presence of anthraquinone disulfonate, were conducted by varying the [cell]/[lepidocrocite] ratio in order to determine whether different types of aggregate are formed, which may facilitate precipitation of GR1 as opposed to magnetite. Confocal laser scanning microscopy was used to analyze the relative cell surface area and lepidocrocite concentration within the aggregates and captured images were characterized by statistical methods for spatial data (i.e. variograms). These results suggest that the [cell]/[lepidocrocite] ratio influenced both the aggregate structure and the nature of the secondary iron mineral formed. Subsequently, a [cell]/[lepidocrocite] ratio above 1 x 10(7) cells mmol(-1) leads to densely packed aggregates and to the formation of GR1. Below this ratio, looser aggregates are formed and magnetite was systematically produced. The data presented in this study bring us closer to a more comprehensive understanding of the parameters governing the formation of minerals in dense bacterial suspensions and suggest that screening mineral-bacteria aggregate structure is critical to understanding (bio)mineralization pathways.

  8. A traumatic hepatic artery pseudoaneurysm and arterioportal fistula, with severe diarrhea as the first symptom: A case report and review of the literature.

    PubMed

    Han, Ping; Yang, Lan; Huang, Xiao-Wei; Zhu, Xiu-Qin; Chen, Li; Wang, Nan; Li, Zhen; Tian, De-An; Qin, Hua

    2018-02-01

    Hepaticarterioportal fistula (APF) is a rare cause of portal hypertension and gastrointestinal hemorrhage, and presents as abnormal communication between the hepatic artery and portal vein. Percutaneous liver biopsy is a main iatrogenic cause of AFP. However, non-iatrogenic, abdominal, trauma-related APF is rarely reported. A 29-year-old man presenting with severe, watery diarrhea was transferred to our hospital, and his condition was suspected to be acute gastroenteritis because he ate expired food and suffered a penetrating abdominal stab wound 5 years ago. After admission, the patient suffered from hematemesis, hematochezia, ascites, anuria, and kidney failure, and he developed shock. The patient was finally diagnosed as a traumatic hepatic artery pseudoaneurysm and APF. This patient was treated with emergency transarterial embolization using coils. Since a secondary feeding vessel was exposed after the first embolization of the main feeding artery, a less-selective embolization was performed again. During the 6-month follow-up period, the patient remained asymptomatic. A penetrating abdominal stab wound is a rare cause of hepatic APFs, and occasionally leads to portal hypertension, the medical history and physical examination are the most important cornerstones of clinical diagnosis. Interventional radiology is essential for the diagnosis and treatment of an APF.

  9. Physical parameters effect on ozone-initiated formation of indoor secondary organic aerosols with emissions from cleaning products.

    PubMed

    Huang, Yu; Ho, Kin Fai; Ho, Steven Sai Hang; Lee, Shun Cheng; Yau, P S; Cheng, Yan

    2011-09-15

    The effect of air exchange rate (ACH), temperature (T), and relative humidity (RH) on the formation of indoor secondary organic aerosols (SOAs) through ozonolysis of biogenic organic compounds (BVOCs) emitted from floor cleaner was investigated in this study. The total particle count (with D(p) of 6-225 nm) was up to 1.2 × 10(3)#cm(-3) with ACH of 1.08 h(-1), and it became much more significant with ACH of 0.36 h(-1) (1.1 × 10(4)#cm(-3)). This suggests that a higher ventilation rate can effectively dilute indoor BVOCs, resulting in a less ultrafine particle formation. The total particle count increased when temperature changed from 15 to 23 °C but it decreased when the temperature further increased to 30 °C. It could be explained that high temperature restrained the condensation of formed semi-volatile compounds resulting in low yields of SOAs. When the RH was at 50% and 80%, SOA formation (1.1-1.2 × 10(4)#cm(-3)) was the more efficient compared with that at RH of 30% (5.9 × 10(3)#cm(-3)), suggesting higher RH facilitating the initial nucleation processes. Oxidation generated secondary carbonyl compounds were also quantified. Acetone was the most abundant carbonyl compound. The formation mechanisms of formaldehyde and acetone were proposed. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. Recurrent secondary postpartum hemorrhages due to placental site vessel subinvolution and local uterine tissue coagulopathy

    PubMed Central

    2014-01-01

    Background Postpartum hemorrhage (PPH) represents a serious problem for women and obstetricians. Because of its association with hemorrhagic shock and predisposition to disseminated coagulopathy, it is a leading cause of maternal deaths worldwide. Furthermore, the jeopardy of PPH is rising with the secondary form of PPH occurring between 24 hours and 6 weeks postpartum, when women are already discharged home. The causes of this pathology are severe inflammation (endometritis), inherited coagulation disorders, consumptive coagulopathy, and retained products of conceptions. Others are of rare occurrence, such as vessel subinvolution (VSI) of the placental implantation site, uterine artery pseudoaneurysm, or trauma. Case presentation We present a rare form of recurrent secondary postpartum hemorrhage in a woman after uncomplicated cesarean delivery, with review of the literature linked to the management of this situation originating in the rare local VSI in the placental implantation site, defective decidual homeostasis, and coagulopathy confined to the uterus. Conclusion The placental site VSI is one of the rare causes of secondary PPH, and this situation is frequently underdiagnosed by clinicians. The histological confirmation of dilated “clustered”-shaped myometrial arteries partially occluded by thrombi of variable “age” together with the presence of endovascular extravillous trophoblasts confirms the diagnosis. PMID:24558972

  11. Pseudoaneurysm of the thoracic aorta sustained during exposure to a tornado diagnosed with ECG-synchronized CT aortography.

    PubMed

    Chakraborty, Amit; von Herrmann, Paul F; Embertson, Ryan E; Landwehr, Kevin P; Winkler, Michael A

    2016-01-01

    A case of a tornado victim with a delayed presentation of injury to the aortic isthmus is discussed. Tornado forces resemble the forces of high energy explosions, and the injuries that can occur as a result of these forces can be bizarre. The patient presented with the unique computed tomography (CT) findings of isolated pseudoaneurysm of the thoracic aorta in the absence of other traumatic injury to the thorax. Equivocal results of the initial CT aortogram (CTA) were confirmed with ECG-synchronized CTA (ECG-CTA), demonstrating the superiority of ECG-CTA as compared to standard CTA. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Formation of secondary organic aerosol in the Paris pollution plume and its impact on surrounding regions

    NASA Astrophysics Data System (ADS)

    Zhang, Q. J.; Beekmann, M.; Freney, E.; Sellegri, K.; Pichon, J. M.; Schwarzenboeck, A.; Colomb, A.; Bourrianne, T.; Michoud, V.; Borbon, A.

    2015-03-01

    Secondary pollutants such as ozone, secondary inorganic aerosol, and secondary organic aerosol formed in the plume of megacities can affect regional air quality. In the framework of the FP7/EU MEGAPOLI project, an intensive campaign was launched in the Greater Paris Region in July 2009. The major objective was to quantify different sources of organic aerosol (OA) within a megacity and in its plume. In this study, we use airborne measurements aboard the French ATR-42 aircraft to evaluate the regional chemistry-transport model CHIMERE within and downwind the Paris region. Slopes of the plume OA levels vs. Ox (= O3 + NO2) show secondary OA (SOA) formation normalized with respect to photochemical activity and are used for specific evaluation of the OA scheme in the model. Simulated and observed slopes are in good agreement, when the most realistic "high-NOx" yields are used in the Volatility-Basis-Set scheme implemented into the model. In addition, these slopes are relatively stable from one day to another, which suggest that they are characteristic for the given megacity plume environment. Since OA within the plume is mainly formed from anthropogenic precursors (VOC and primary OA, POA), this work allows a specific evaluation of anthropogenic SOA and SOA formed from primary semi-volatile and intermediate volatile VOCs (SI-SOA) formation scheme in a model. For specific plumes, this anthropogenic OA build-up can reach about 10 μg m-3. For the average of the month of July 2009, maximum increases occur close to the agglomeration for primary OA are noticed at several tens (for POA) to hundred (for SI-SOA) kilometers of distance from the Paris agglomeration.

  13. Observations of fine particulate nitrated phenols in four sites in northern China: concentrations, source apportionment, and secondary formation

    NASA Astrophysics Data System (ADS)

    Wang, Liwei; Wang, Xinfeng; Gu, Rongrong; Wang, Hao; Yao, Lan; Wen, Liang; Zhu, Fanping; Wang, Weihao; Xue, Likun; Yang, Lingxiao; Lu, Keding; Chen, Jianmin; Wang, Tao; Zhang, Yuanghang; Wang, Wenxing

    2018-03-01

    Filter samples of fine particulate matters were collected at four sites in northern China (urban, rural, and mountain) in summer and winter, and the contents of nine nitrated phenols were quantified in the laboratory with the use of ultra-high-performance liquid chromatography coupled with mass spectrometry. During the sampling periods, the concentrations of particulate nitrated phenols exhibited distinct temporal and spatial variation. On average, the total concentration of particulate nitrated phenols in urban Jinan in the wintertime reached 48.4 ng m-3, and those in the summertime were 9.8, 5.7, 5.9, and 2.5 ng m-3 in urban Jinan, rural Yucheng and Wangdu, and Mt. Tai, respectively. The elevated concentrations of nitrated phenols in wintertime and in urban areas demonstrate the apparent influences of anthropogenic sources. The positive matrix factorization receptor model was then applied to determine the origins of particulate nitrated phenols in northern China. The five major source factors were traffic, coal combustion, biomass burning, secondary formation, and aged coal combustion plume. Among them, coal combustion played a vital role, especially at the urban site in the wintertime, with a contribution of around 55 %. In the summertime, the observed nitrated phenols were highly influenced by aged coal combustion plumes at all of the sampling sites. Meanwhile, in remote areas, contributions from secondary formation were significant. Further correlation analysis indicates that nitrosalicylic acids were produced mostly from secondary formation that was dominated by NO2 nitration.

  14. How Does Tropical Cyclone Size Affect the Onset Timing of Secondary Eyewall Formation?

    NASA Astrophysics Data System (ADS)

    Guan, Liang; Ge, Xuyang

    2018-02-01

    By using idealized numerical simulations, the impact of tropical cyclone size on secondary eyewall formation (SEF) is examined. Both unbalanced boundary layer and balanced processes are examined to reveal the underlying mechanism. The results show that a tropical cyclone (TC) with a larger initial size favors a quicker SEF and a larger outer eyewall. For a TC with a larger initial size, it will lead to a stronger surface entropy flux, and thus more active outer convection. Meanwhile, a greater inertial stability helps the conversion from diabatic heating to kinetic energy. Furthermore, the progressively broadening of the tangential wind field will induce significant boundary layer imbalances. This unbalanced boundary layer process results in a supergradient wind zone that acts as an important mechanism for triggering and maintaining deep convection. In short, different behaviors of balanced and unbalanced processes associated with the initial wind profile lead to different development rates of the secondary eyewall.

  15. Secondary organic aerosol formation from ozone-initiated reactions with nicotine and secondhand tobacco smoke

    NASA Astrophysics Data System (ADS)

    Sleiman, Mohamad; Destaillats, Hugo; Smith, Jared D.; Liu, Chen-Lin; Ahmed, Musahid; Wilson, Kevin R.; Gundel, Lara A.

    2010-11-01

    We used controlled laboratory experiments to evaluate the aerosol-forming potential of ozone reactions with nicotine and secondhand smoke. Special attention was devoted to real-time monitoring of the particle size distribution and chemical composition of SOA as they are believed to be key factors determining the toxicity of SOA. The experimental approach was based on using a vacuum ultraviolet photon ionization time-of-flight aerosol mass spectrometer (VUV-AMS), a scanning mobility particle sizer (SMPS) and off-line thermal desorption coupled to mass spectrometry (TD-GC-MS) for gas-phase byproducts analysis. Results showed that exposure of SHS to ozone induced the formation of ultrafine particles (<100 nm) that contained high molecular weight nitrogenated species ( m/ z 400-500), which can be due to accretion/acid-base reactions and formation of oligomers. In addition, nicotine was found to contribute significantly (with yields 4-9%) to the formation of secondary organic aerosol through reaction with ozone. The main constituents of the resulting SOA were tentatively identified and a reaction mechanism was proposed to elucidate their formation. These findings identify a new component of thirdhand smoke that is associated with the formation of ultrafine particles (UFP) through oxidative aging of secondhand smoke. The significance of this chemistry for indoor exposure and health effects is highlighted.

  16. Formation of Polychlorinated Biphenyls on Secondary Copper Production Fly Ash: Mechanistic Aspects and Correlation to Other Persistent Organic Pollutants

    NASA Astrophysics Data System (ADS)

    Jiang, Xiaoxu; Liu, Guorui; Wang, Mei; Zheng, Minghui

    2015-09-01

    Emission of unintentionally formed polychlorinated biphenyls (PCBs) from industrial thermal processes is a global issue. Because the production and use of technical PCB mixtures has been banned, industrial thermal processes have become increasingly important sources of PCBs. Among these processes, secondary copper smelting is an important PCB source in China. In the present study, the potential for fly ash-mediated formation of PCBs in the secondary copper industry, and the mechanisms involved, were studied in laboratory thermochemical experiments. The total PCB concentrations were 37-70 times higher than the initial concentrations. Thermochemical reactions on the fly ash amplified the potential toxic equivalents of PCBs. The formation of PCBs over time and the effect of temperature were investigated. Based on analyses of PCB homologue profiles with different reaction conditions, a chlorination mechanism was proposed for forming PCBs in addition to a de novo synthesis mechanism. The chlorination pathway was supported by close correlations between each pair of adjacent homologue groups. Formation of PCBs and multiple persistent organic pollutants, including polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and polychlorinated naphthalenes, occurred during the tests, indicating that these compounds may share similar formation mechanisms.

  17. Typical winter haze pollution in Zibo, an industrial city in China: Characteristics, secondary formation, and regional contribution.

    PubMed

    Li, Hui; Ma, Yongliang; Duan, Fengkui; He, Kebin; Zhu, Lidan; Huang, Tao; Kimoto, Takashi; Ma, Xiaoxuan; Ma, Tao; Xu, Lili; Xu, Beiyao; Yang, Shuo; Ye, Siqi; Sun, Zhenli; An, Jiutao; Zhang, Zhaolu

    2017-10-01

    Heavy haze pollution occurs frequently in northern China, most critically in the Beijing-Tianjin-Hebei area (BTH). Zibo, an industrial city located in Shandong province, is often listed as one of the top ten most polluted cities in China, particularly in winter. However, no studies of haze in Zibo have been conducted, which limits the understanding of the source and formation of haze pollution in this area, as well as mutual effects with the BTH area. We carried out online and continuous integrated field observation of particulate matter in winter, from 11 to 25 January 2015. SO 4 2- , NO 3 - , and NH 4 + (SIA) and organics were the main constituents of PM 2.5 , contributing 59.4% and 33.6%, respectively. With the increasing severity of pollution, the contribution of SIA increased while that of organics decreased. Meteorological conditions play an important role in haze formation; high relative humidity (RH) and low wind speed increased both the accumulation of pollutants and the secondary transition from gas precursors (gas-particle phase partitioning). Since RH and the presence of O 3 can indicate heterogeneous and photochemistry processes, respectively, we carried out correlation analysis and linear regression to identify their relative importance to the three main secondary species (sulfate, nitrate, and secondary organic carbon (SOC)). We found that the impact of RH is in the order of SO 4 2-  > NO 3 -  > SOC, while the impact of O 3 is reversed, in the order of SOC > NO 3 -  > SO 4 2- , indicating different effect of these factors on the secondary formation of main species in winter. Cluster analysis of backward trajectories showed that, during the observation period, six directional sources of air masses were identified, and more than 90% came from highly industrialized areas, indicating that regional transport from industrialized areas aggravates the haze pollution in Zibo. Inter-regional joint prevention and control is necessary to prevent further

  18. Theoretical investigation about secondary deposition of thin-film formation by molecular dynamics simulation

    NASA Astrophysics Data System (ADS)

    Chen, Huawei; Hagiwara, Ichiro; Kiet Tieu, A.; Kishimoto, Kikuo; Liu, Qiang

    2007-05-01

    The thin-film growth has been confirmed to be assembled by an enormous number of clusters in experiments of CVD. Sequence of clusters' depositions proceeds to form the thin-film in short time as gas fluids through surface of substrate. Such growth mechanism has been mainly investigated on the basis of experiment. Due to immense cost of the experimental equipment and low level of current measurement technology, the comprehension about authentic effect of formation condition on properties of nanomaterial is limited in qualitative manner. Three quantitative items: flatness of primary deposition, adhesion between cluster and substrate, and degree of epitaxial growth were proposed to evaluate the property of thin-film. In this simulation, three different cluster sizes of 203, 653, and 1563 atoms with different velocities (0, 10, 100, 1000, and 3000 m/s) were deposited on a Cu(0 0 1) substrate whose temperatures were set between 300 and 1000 K. Four clusters and one cluster were used in primary deposition and secondary deposition, respectively. To increase initial velocity not only enhanced the speed of epitaxial growth, adhesion between clusters and substrate, but also increased the degree of epitaxy for primary deposition and secondary deposition. Exfoliation pattern of thin-film was profoundly dependent on initial velocity through comparison between adhesion of primary and secondary deposition. Moreover, the epitaxial growth became well as the temperature of substrate was raised, and the degree of epitaxy of small cluster was larger than that of larger cluster, no matter of primary and secondary deposition.

  19. Deep Circumflex Iliac Artery-Related Hemoperitoneum Formation After Surgical Drain Placement: Successful Transcatheter Embolization

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Park, Sang Woo; Chang, Seong-Hwan, E-mail: csh@kuh.ac.kr; Yun, Ik Jin

    A 53-year-old woman with liver cirrhosis and hepatocellular carcinoma underwent living donor liver transplantation. After transplantation, her hemoglobin and hematocrit levels decreased to 6.3 g/dl and 18.5%, respectively, during the course of 3 days. A contrast-enhanced abdominal computed axial tomography (CAT) scan showed a hemoperitoneum in the right perihepatic space with no evidence of abdominal wall hematoma or pseudoaneurysm formation. An angiogram of the deep circumflex iliac artery (DCIA) showed extravasation of contrast media along the surgical drain, which had been inserted during the transplantation procedure. Transcatheter embolization of the branches of the DCIA was successfully performed using N-butyl cyanoacrylate.

  20. Influence of Different PBL Schemes on Secondary Eyewall Formation and Eyewall Replacement Cycle in Simulated Typhoon Sinlaku (2008)

    NASA Astrophysics Data System (ADS)

    Zhang, Yutao

    2017-04-01

    The effects of the different planetary boundary layer (PBL) processes on the secondary eyewall formation (SEF) and eyewall replacement cycle (ERC) in Typhoon Sinlaku (2008) are investigated by using the Weather Research and Forecasting Model (WRF) with six different PBL schemes. The SEF and ERC have been successfully simulated with all the six PBL schemes and the mechanism of the SEF and ERC proposed in our previous study has been reconfirmed: It is demonstrated that both the intensification of the storm and the inward-moving outer spiral rainband contribute to the SEF. After the SEF, the associated diabatic heating enhances the secondary eyewall further and transfer of the moist air from outer region to the primary eyewall is cut off by the secondary eyewall. In such a way the primary eyewall dies and an ERC completes. It is found that some simulated features of the SEF and ERC, such as the time and location of the SEF and duration of the ERC, do vary from one simulation to another. In order to describe the feature of the SEF and ERC quantitatively, a concentric eyewall index (CEI) is defined and a threshold of the CEI is suggested to determine the onset of the secondary eyewall. The differences of the simulated SEF and ERC are discussed and some possible causes are suggested. In addition, based on the threshold of the CEI and the conservation law of the angular momentum a formula to predict the location of the SEF is also suggested and applied to all the six simulations. The success and failure of the formula are also discussed. Key words: eye-wall replacement cycle, secondary eye-wall formation, PBL scheme, CEI

  1. High risk of fistula formation in vacuum-assisted closure therapy in patients with open abdomen due to secondary peritonitis-a retrospective analysis.

    PubMed

    Mintziras, Ioannis; Miligkos, Michael; Bartsch, Detlef Klaus

    2016-08-01

    The aim of this study was to evaluate the efficacy of vacuum-assisted closure therapy in patients with open abdomen due to secondary peritonitis and to identify possible risk factors of fistula formation. The hospital OPS-database (time period 2005-2014) was searched to identify patients treated with an open abdomen due to secondary peritonitis, who underwent vacuum-assisted closure therapy. Medical records were retrospectively analyzed for patients' characteristics, cause of peritonitis, duration of vacuum therapy, number of relaparotomies, fascial closure rates, and risk factors of fistula formation. Forty-three patients (19 male, 24 female) with a median age of 65 years (range 24-90 years) were identified. The major cause of secondary peritonitis was anastomotic leakage after intestinal anastomosis or bowel perforation, the median APACHE II score was 11. Median duration of VAC treatment was 12 days (range 3-88 days). Twenty of 43 (47 %) patients died from septic complications. Delayed fascial closure was obtained by suturing in 20 of 43 patients (47 %). Overall 16 of 43 (37 %) patients developed enteroatmospheric fistulas. Re-explorations after starting VAC treatment and duration of VAC therapy were significantly associated with the occurrence of enteroatmospheric fistulas (p < 0.001). ROC curve analysis determined the optimal duration of VAC therapy to reduce the risk of fistula formation at 13 days. Long-term VAC treatment of patients with an open abdomen due to secondary peritonitis results in a relatively low fascial closure rate and a high risk of fistula formation.

  2. Uptake of Alkylamines on Dicarboxylic Acids Relevant to Secondary Organic Aerosol Formation

    NASA Astrophysics Data System (ADS)

    Marrero-Ortiz, W.; Secrest, J.; Zhang, R.

    2017-12-01

    Aerosols play a critical role in climate directly by scattering and absorbing solar radiation, and indirectly by functioning as cloud condensation nuclei (CCN); both represent the largest uncertainties in climate predictions. New particle formation contributes significantly to CCN production; however, the mechanisms related to particle nucleation and growth processes are not well understood. Organic acids are atmospherically abundant, and their neutralization by low molecular weight amines may result in the formation of stable low volatility aminium salt products contributing to the growth of secondary organic aerosols and even the alteration of the aerosol properties. The acid-base neutralization of particle phase succinic acid and tartaric acid by low molecular weight aliphatic amines, i.e. methylamine, dimethylamine, and trimethylamine, has been investigated by employing a low-pressure fast flow reactor at 298K with an ion drift - chemical ionization mass spectrometer (ID-CIMS). The heterogeneous uptake is time dependent and influenced by organic acids functionality, alkylamines basicity, and steric effect. The implications of our results to atmospheric nanoparticle growth will be discussed.

  3. Onyx, a New Liquid Embolic Material for Peripheral Interventions: Preliminary Experience in Aneurysm, Pseudoaneurysm, and Pulmonary Arteriovenous Malformation Embolization

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Vanninen, Ritva L., E-mail: ritva.vanninen@kuh.fi; Manninen, I.

    Purpose. To describe our preliminary experience with a new liquid embolization agent, Onyx, in peripheral interventions. Methods and results. We successfully treated two peripheral aneurysms (one in an internal iliac artery, one in a thoracic collateral artery of an aortic coarctation), two peripheral pseudoaneurysms (one in a lumbar artery, one in a renal artery), and one pulmonary arteriovenous malformation. Conclusion. Onyx is a promising alternative embolic material for peripheral interventions. It can be combined with coils in selected cases, and balloon catheters can be effectively used during slow injection of embolic material to control flow and protect the aneurysm neck.

  4. Management of a traumatic hepatic artery pseudoaneurysm and arterioportal fistula with a combination of a stent graft and coil embolization using flow control with balloon remodeling.

    PubMed

    Flum, Andrew S; Geiger, James D; Gemmete, Joseph J; Williams, David M; Teitelbaum, Daniel H

    2009-10-01

    We describe a child who presented with a traumatic hepatic artery pseudoaneurysm and arterioportal fistula, which were subsequently managed with an endovascular stent graft and coil embolization using flow control with balloon remodeling. This case demonstrates a rarely seen condition in the pediatric population and a novel management strategy, which should be considered in the management of this complex injury.

  5. Secondary Organic Aerosol Formation from the Photooxidation of Naphthalene

    NASA Astrophysics Data System (ADS)

    Zhou, S.; Chen, Y.; Wenger, J.

    2009-04-01

    Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous air pollutants that are released into the atmosphere as a by-product of combustion processes. The gas-phase PAHs can be chemically transformed via reaction with the hydroxyl radical to produce a range of oxidised organic compounds and other pollutants such as ozone and secondary organic aerosol (SOA). Epidemiological studies have established that exposure to this type of air pollution is associated with damaging effects on the respiratory and cardiovascular systems, and can lead to asthma, oxidative stress, health deterioration and even death. The major anthropogenic source of SOA in urban areas is believed to be aromatic hydrocarbons, which are present in automobile fuels and are used as solvents. As a result, research is currently being performed on the characterisation of SOA produced from aromatic hydrocarbons such as toluene, the xylenes and trimethylbenzenes. However, significant amounts of PAHs are also released into urban areas from automobile emissions and the combustion of fossil fuels for home heating. Naphthalene is regularly cited as the most abundant PAH in polluted urban air, with typical ambient air concentrations of 0.05 - 0.20 parts per billion (ppbV) in European cities, comparable to the xylenes. Since naphthalene reacts in an analogous manner to monocyclic aromatic compounds then it is also expected to make a significant contribution to ambient SOA. However, the yield and chemical composition of SOA produced from the atmospheric degradation of naphthalene is not well known. In this presentation, the effects of NOx level and relative humidity on the SOA formation from the phootooixdation of naphthalene will be presented. A series of experiments has been performed in a large atmospheric simulation chamber equipped with a gas chromatograph and analyzers for monitoring nitrogen oxides (NOx) and ozone. SOA formation from the photooxidation of naphthalene was measured using a scanning mobility

  6. [Post-traumatic pseudoaneurysm of an anomalous right hepatic artery with arteriobiliary fistula and hemobilia].

    PubMed

    Bober, J; Vrzgula, A; Samek, P; Mach, P

    1999-09-01

    The authors describe a rare case of posttraumatic pseudoaneurysm of an anomaly arising right hepatic artery accompanied with arteriobiliary fistula. Treacherousness of this case was given by anomaly origin of the affected vessel. Thirty-four year old female has been treated at the author's department after sustained knife abdominal injury. Before our treatment, she was twice operated at the other hospital for haemoperitoneum and subhepatic abscess with haemobilia. The patient was transferred to the 1st department of surgery in Kosice because of septic shock, right-lobe hepatic abscess and repeated haemobilia. Selective hepatico-mesentericography revealed the cause of haemobilia. At the operation a double ligation of anomaly right hepatic artery was carried out together with closure of arteriobiliary fistula via choledochotomy. Haemobilia was not seen after surgery and the patient was discharged without any signs of liver disfunction. Repeated angiography showed closure of anomaly arising vessel.

  7. Efficient Isoprene Secondary Organic Aerosol Formation from a Non-IEPOX Pathway

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Liu, Jiumeng; D’Ambro, Emma L.; Lee, Ben H.

    2016-09-20

    With a large global emission rate and high reactivity, isoprene has a profound effect upon atmospheric chemistry and composition. The atmospheric pathways by which isoprene converts to secondary organic aerosol (SOA) and how anthropogenic pollutants such as nitrogen oxides and sulfur affect this process are a subject of intense research because particles affect Earth’s climate and local air quality. In the absence of both nitrogen oxides and reactive aqueous seed particles, we measure SOA mass yields from isoprene photochemical oxidation of up to 15%, which are factors of 2, or more, higher than those typically used in coupled chemistry-climate models.more » SOA yield is initially constant with the addition of increasing amounts of nitric oxide (NO) but then sharply decreases for input concentrations above 10 ppbv. Online measurements of aerosol molecular composition show that the fate of second-generation RO2 radicals is key to understanding the efficient SOA formation and the NOx dependent yields described here and in the literature. These insights allow for improved quantitative estimates of SOA formation in the pre-industrial atmosphere and in biogenic-rich regions with limited anthropogenic impacts and suggest a more complex representation of NOx dependent SOA yields may be important in models.« less

  8. PtrWRKY19, a novel WRKY transcription factor, contributes to the regulation of pith secondary wall formation in Populus trichocarpa.

    PubMed

    Yang, Li; Zhao, Xin; Yang, Fan; Fan, Di; Jiang, Yuanzhong; Luo, Keming

    2016-01-28

    WRKY proteins are one of the largest transcription factor families in higher plants and play diverse roles in various biological processes. Previous studies have shown that some WRKY members act as negative regulators of secondary cell wall formation in pith parenchyma cells. However, the regulatory mechanism of pith secondary wall formation in tree species remains largely unknown. In this study, PtrWRKY19 encoding a homolog of Arabidopsis WRKY12 was isolated from Populus trichocarpa. PtrWRKY19 was expressed in all tissues tested, with highest expression in stems, especially in pith. PtrWRKY19 was located in the nucleus and functioned as a transcriptional repressor. Ectopic expression of PtrWRKY19 in an atwrky12 mutant successfully rescued the phenotype in pith cell walls caused by the defect of AtWRKY12, suggesting that PtrWRKY19 had conserved functions for homologous AtWRKY12. Overexpression of PtrWRKY19 in poplar plants led to a significant increase in the number of pith parenchyma cells. qRT-PCR analysis showed that lignin biosynthesis-related genes were repressed in transgenic plants. In transcient reporter assays, PtrWRKY19 was identified to repress transcription from the PtoC4H2 promoter containing the conserved W-box elements. These results indicated that PtrWRKY19 may function as a negative regulator of pith secondary wall formation in poplar.

  9. Formation of secondary inorganic aerosols by power plant emissions exhausted through cooling towers in Saxony.

    PubMed

    Hinneburg, Detlef; Renner, Eberhard; Wolke, Ralf

    2009-01-01

    The fraction of ambient PM10 that is due to the formation of secondary inorganic particulate sulfate and nitrate from the emissions of two large, brown-coal-fired power stations in Saxony (East Germany) is examined. The power stations are equipped with natural-draft cooling towers. The flue gases are directly piped into the cooling towers, thereby receiving an additionally intensified uplift. The exhausted gas-steam mixture contains the gases CO, CO2, NO, NO2, and SO2, the directly emitted primary particles, and additionally, an excess of 'free' sulfate ions in water solution, which, after the desulfurization steps, remain non-neutralized by cations. The precursor gases NO2 and SO2 are capable of forming nitric and sulfuric acid by several pathways. The acids can be neutralized by ammonia and generate secondary particulate matter by heterogeneous condensation on preexisting particles. The simulations are performed by a nested and multi-scale application of the online-coupled model system LM-MUSCAT. The Local Model (LM; recently renamed as COSMO) of the German Weather Service performs the meteorological processes, while the Multi-scale Atmospheric Transport Model (MUSCAT) includes the transport, the gas phase chemistry, as well as the aerosol chemistry (thermodynamic ammonium-sulfate-nitrate-water system). The highest horizontal resolution in the inner region of Saxony is 0.7 km. One summer and one winter episode, each realizing 5 weeks of the year 2002, are simulated twice, with the cooling tower emissions switched on and off, respectively. This procedure serves to identify the direct and indirect influences of the single plumes on the formation and distribution of the secondary inorganic aerosols. Surface traces of the individual tower plumes can be located and distinguished, especially in the well-mixed boundary layer in daytime. At night, the plumes are decoupled from the surface. In no case does the resulting contribution of the cooling tower emissions to PM10

  10. CHRONOLOGICAL CONSTRAINTS ON FLUID CIRCULATION IN MESOZOIC FORMATIONS OF THE EASTERN PART OF THE PARIS BASIN INFERRED FROM U-Pb DATING OF SECONDARY INFILLING CARBONATES

    NASA Astrophysics Data System (ADS)

    Pisapia, C.; Deschamps, P.; Hamelin, B.; Buschaert, S.

    2009-12-01

    The French agency for nuclear waste management (ANDRA) developed an Underground Research Laboratory in the Mesozoic formations of Eastern part of the Paris Basin (France) to assess the feasibility of a high-level radioactive wastes repository in sedimentary formations. The target host formation is a low-porosity detrital argillite (Callovo-Oxfordian) embedded between two shelf limestones formations (of Bajocian-Bathonian and Oxfordian-Kimmeridgian ages). These formations are affected by fracture networks, likely inherited mainly from the Eocene-Oligocene extension tectonics, also responsible of the Rhine graben formation in the same region. The limestones have very low permeability, the primary and secondary porosity being infilled by secondary carbonated minerals. The inter-particle porosity is filled with euhedral calcite spar cements. Similarly, macro-cavities and connected micro-fractures are almost sealed by euhedral calcite. Geochemical evidences (δ18O) suggest that the secondary carbonates likely derived from a common parent fluid (Buschaert et al., 2004, Appl. Geochem. (19) 1201-1215p). This late carbonated precipitation phase is responsible for the intense cementation of the limestone formations and bears witness of a major phase of fluids circulation that marked the late diagenetic evolution of the system. Knowledge of the chronology of the different precipitation phases of secondary minerals is thus of critical importance in order to determine the past hydrological conditions of the geological site. The aim of this study is to provide chronological constraints on the secondary carbonate mineral precipitation using U/Th and U/Pb methods. Analyses are performed on millimeter to centimeter scale secondary calcites collected within fractures outcropping in the regional fault zone of Gondrecourt and in cores from the ANDRA exploration-drilling program. Preliminary U-Th analyses obtained on secondary carbonates from surface fractures infillings yield secular

  11. Kinetic modeling of secondary organic aerosol formation: effects of particle- and gas-phase reactions of semivolatile products

    NASA Astrophysics Data System (ADS)

    Chan, A. W. H.; Kroll, J. H.; Ng, N. L.; Seinfeld, J. H.

    2007-08-01

    The distinguishing mechanism of formation of secondary organic aerosol (SOA) is the partitioning of semivolatile hydrocarbon oxidation products between the gas and aerosol phases. While SOA formation is typically described in terms of partitioning only, the rate of formation and ultimate yield of SOA can also depend on the kinetics of both gas- and aerosol-phase processes. We present a general equilibrium/kinetic model of SOA formation that provides a framework for evaluating the extent to which the controlling mechanisms of SOA formation can be inferred from laboratory chamber data. With this model we examine the effect on SOA formation of gas-phase oxidation of first-generation products to either more or less volatile species, of particle-phase reaction (both first- and second-order kinetics), of the rate of parent hydrocarbon oxidation, and of the extent of reaction of the parent hydrocarbon. The effect of pre-existing organic aerosol mass on SOA yield, an issue of direct relevance to the translation of laboratory data to atmospheric applications, is examined. The importance of direct chemical measurements of gas- and particle-phase species is underscored in identifying SOA formation mechanisms.

  12. Kinetic modeling of Secondary Organic Aerosol formation: effects of particle- and gas-phase reactions of semivolatile products

    NASA Astrophysics Data System (ADS)

    Chan, A. W. H.; Kroll, J. H.; Ng, N. L.; Seinfeld, J. H.

    2007-05-01

    The distinguishing mechanism of formation of secondary organic aerosol (SOA) is the partitioning of semivolatile hydrocarbon oxidation products between the gas and aerosol phases. While SOA formation is typically described in terms of partitioning only, the rate of formation and ultimate yield of SOA can also depend on the kinetics of both gas- and aerosol-phase processes. We present a general equilibrium/kinetic model of SOA formation that provides a framework for evaluating the extent to which the controlling mechanisms of SOA formation can be inferred from laboratory chamber data. With this model we examine the effect on SOA formation of gas-phase oxidation of first-generation products to either more or less volatile species, of particle-phase reaction (both first- and second-order kinetics), of the rate of parent hydrocarbon oxidation, and of the extent of reaction of the parent hydrocarbon. The effect of pre-existing organic aerosol mass on SOA yield, an issue of direct relevance to the translation of laboratory data to atmospheric applications, is examined. The importance of direct chemical measurements of gas- and particle-phase species is underscored in identifying SOA formation mechanisms.

  13. Understanding the primary emissions and secondary formation of gaseous organic acids in the oil sands region of Alberta, Canada

    NASA Astrophysics Data System (ADS)

    Liggio, John; Moussa, Samar G.; Wentzell, Jeremy; Darlington, Andrea; Liu, Peter; Leithead, Amy; Hayden, Katherine; O'Brien, Jason; Mittermeier, Richard L.; Staebler, Ralf; Wolde, Mengistu; Li, Shao-Meng

    2017-07-01

    Organic acids are known to be emitted from combustion processes and are key photochemical products of biogenic and anthropogenic precursors. Despite their multiple environmental impacts, such as on acid deposition and human-ecosystem health, little is known regarding their emission magnitudes or detailed chemical formation mechanisms. In the current work, airborne measurements of 18 gas-phase low-molecular-weight organic acids were made in the summer of 2013 over the oil sands region of Alberta, Canada, an area of intense unconventional oil extraction. The data from these measurements were used in conjunction with emission retrieval algorithms to derive the total and speciated primary organic acid emission rates, as well as secondary formation rates downwind of oil sands operations. The results of the analysis indicate that approximately 12 t day-1 of low-molecular-weight organic acids, dominated by C1-C5 acids, were emitted directly from off-road diesel vehicles within open pit mines. Although there are no specific reporting requirements for primary organic acids, the measured emissions were similar in magnitude to primary oxygenated hydrocarbon emissions, for which there are reporting thresholds, measured previously ( ≈ 20 t day-1). Conversely, photochemical production of gaseous organic acids significantly exceeded the primary sources, with formation rates of up to ≈ 184 t day-1 downwind of the oil sands facilities. The formation and evolution of organic acids from a Lagrangian flight were modelled with a box model, incorporating a detailed hydrocarbon reaction mechanism extracted from the Master Chemical Mechanism (v3.3). Despite evidence of significant secondary organic acid formation, the explicit chemical box model largely underestimated their formation in the oil sands plumes, accounting for 39, 46, 26, and 23 % of the measured formic, acetic, acrylic, and propionic acids respectively and with little contributions from biogenic VOC precursors. The model

  14. Virus-induced gene silencing (VIGS)-mediated functional characterization of two genes involved in lignocellulosic secondary cell wall formation.

    PubMed

    Pandey, Shashank K; Nookaraju, Akula; Fujino, Takeshi; Pattathil, Sivakumar; Joshi, Chandrashekhar P

    2016-11-01

    Functional characterization of two tobacco genes, one involved in xylan synthesis and the other, a positive regulator of secondary cell wall formation, is reported. Lignocellulosic secondary cell walls (SCW) provide essential plant materials for the production of second-generation bioethanol. Therefore, thorough understanding of the process of SCW formation in plants is beneficial for efficient bioethanol production. Recently, we provided the first proof-of-concept for using virus-induced gene silencing (VIGS) approach for rapid functional characterization of nine genes involved in cellulose, hemicellulose and lignin synthesis during SCW formation. Here, we report VIGS-mediated functional characterization of two tobacco genes involved in SCW formation. Stems of VIGS plants silenced for both selected genes showed increased amount of xylem formation but thinner cell walls than controls. These results were further confirmed by production of stable transgenic tobacco plants manipulated in expression of these genes. Stems of stable transgenic tobacco plants silenced for these two genes showed increased xylem proliferation with thinner walls, whereas transgenic tobacco plants overexpressing these two genes showed increased fiber cell wall thickness but no change in xylem proliferation. These two selected genes were later identified as possible members of DUF579 family involved in xylan synthesis and KNAT7 transcription factor family involved in positive regulation of SCW formation, respectively. Glycome analyses of cell walls showed increased polysaccharide extractability in 1 M KOH extracts of both VIGS-NbDUF579 and VIGS-NbKNAT7 lines suggestive of cell wall loosening. Also, VIGS-NbDUF579 and VIGS-NbKNAT7 lines showed increased saccharification rates (74.5 and 40 % higher than controls, respectively). All these properties are highly desirable for producing higher quantities of bioethanol from lignocellulosic materials of bioenergy plants.

  15. SECONDARY ORGANIC AEROSOL FORMATION FROM THE OXIDATION OF AROMATIC HYDROCARBONS IN THE PRESENCE OF DRY SUBMICRON AMMONIUM SULFATE AEROSOL

    EPA Science Inventory

    A laboratory study was conducted to examine formation of secondary organic aerosols. A smog chamber system was developed for studying gas-aerosol interactions in a dynamic flow reactor. These experiments were conducted to investigate the fate of gas and aerosol phase compounds ...

  16. Secondary membrane formation after cataract surgery with primary intraocular lens implantation in children.

    PubMed

    Bar-Sela, Shai M; Har-Noy, Nurit Birman; Spierer, Abraham

    2014-08-01

    To evaluate the risk factors for secondary membrane (SM) formation after congenital cataract surgery with intraocular lens (IOL) implantation. A retrospective non-interventional comparative study. Thirty-nine patients (63 eyes) aged 1-135 months. The study included patients who underwent cataract extraction and primary IOL implantation between 1994 and 2001 at the University Hospital. The postoperative follow-up was 6-24 months. Thirty-three eyes received a poly(methyl methacrylate) (PMMA) IOL without square edges, 29 eyes received a hydrophobic acrylic IOL with truncated square edges (AcrySof), and there was no data for IOL type in one eye. Thirty-nine eyes had primary posterior capsulotomy (PPC) and anterior vitrectomy (AV) and in 24 eyes the posterior capsule was left intact. Cox proportional hazard regression analysis was performed to identify significant risk factors for SM formation, and Wilcoxon test to evaluate the difference in time from surgery to SM formation. SM developed in 24 eyes (38 %)--58 % of eyes with an intact posterior capsule and 26 % of eyes having PPC and AV, 42 % of eyes with a PMMA IOL, and 34 % of eyes with an AcrySof lens. In multivariate Cox regression analysis intraoperative PPC and AV (P = 0.02) and AcrySof lens implantation (P = 0.097) were associated with decreased postoperative incidence of SM formation. Median time until SM development was 2.9 months with PMMA IOLs (range 1-17 months) and 6 months with AcrySof lenses (range 1-21.8 months) (P = 0.037). Posterior capsule management as well as IOL design and material influence the incidence and the timing of SM formation after primary IOL implantation in children.

  17. Modelling of Criegee Intermediates using the 3-D global model, STOCHEM-CRI and investigating their global impacts on Secondary Organic Aerosol formation

    NASA Astrophysics Data System (ADS)

    Khan, M. Anwar H.; Cooke, Michael; Utembe, Steve; Archibald, Alexander; Derwent, Richard; Jenkin, Mike; Lyons, Kyle; Kent, Adam; Percival, Carl; Shallcross, Dudley E.

    2016-04-01

    Gas phase reactions of ozone with unsaturated compounds form stabilized Criegee intermediates (sCI) which play an important role in controlling the budgets of many tropospheric species including OH, organic acids and secondary organic aerosols (SOA). Recently sCI has been proposed to play a significant role in atmospheric sulfate and nitrate chemistry by forming sulfuric acid (promoter of aerosol formation) and nitrate radical (a powerful oxidizing agent). sCI can also undergo association reactions with water, alcohols, and carboxylic acids to form hydroperoxides and with aldehydes and ketones to form secondary ozonides. The products from these reactions are low volatility compounds which can contribute to the formation of SOA. The importance of plant emitted alkenes (isoprene, monoterpenes, sesquiterpenes) in the production of SOA through sCI formation have already been investigated in laboratory studies. However, the SOA formation from these reactions are absent in current global models. Thus, the formation of SOA has been incorporated in the global model, STOCHEM-CRI, a 3-D global chemistry transport model and the role of CI chemistry in controlling atmospheric composition and climate, and the influence of water vapor has been discussed in the study.

  18. Formation and evolution of molecular products in α-pinene secondary organic aerosol.

    PubMed

    Zhang, Xuan; McVay, Renee C; Huang, Dan D; Dalleska, Nathan F; Aumont, Bernard; Flagan, Richard C; Seinfeld, John H

    2015-11-17

    Much of our understanding of atmospheric secondary organic aerosol (SOA) formation from volatile organic compounds derives from laboratory chamber measurements, including mass yield and elemental composition. These measurements alone are insufficient to identify the chemical mechanisms of SOA production. We present here a comprehensive dataset on the molecular identity, abundance, and kinetics of α-pinene SOA, a canonical system that has received much attention owing to its importance as an organic aerosol source in the pristine atmosphere. Identified organic species account for ∼58-72% of the α-pinene SOA mass, and are characterized as semivolatile/low-volatility monomers and extremely low volatility dimers, which exhibit comparable oxidation states yet different functionalities. Features of the α-pinene SOA formation process are revealed for the first time, to our knowledge, from the dynamics of individual particle-phase components. Although monomeric products dominate the overall aerosol mass, rapid production of dimers plays a key role in initiating particle growth. Continuous production of monomers is observed after the parent α-pinene is consumed, which cannot be explained solely by gas-phase photochemical production. Additionally, distinct responses of monomers and dimers to α-pinene oxidation by ozone vs. hydroxyl radicals, temperature, and relative humidity are observed. Gas-phase radical combination reactions together with condensed phase rearrangement of labile molecules potentially explain the newly characterized SOA features, thereby opening up further avenues for understanding formation and evolution mechanisms of α-pinene SOA.

  19. High-aluminum-affinity silica is a nanoparticle that seeds secondary aluminosilicate formation.

    PubMed

    Jugdaohsingh, Ravin; Brown, Andy; Dietzel, Martin; Powell, Jonathan J

    2013-01-01

    Despite the importance and abundance of aluminosilicates throughout our natural surroundings, their formation at neutral pH is, surprisingly, a matter of considerable debate. From our experiments in dilute aluminum and silica containing solutions (pH ~ 7) we previously identified a silica polymer with an extraordinarily high affinity for aluminium ions (high-aluminum-affinity silica polymer, HSP). Here, further characterization shows that HSP is a colloid of approximately 2.4 nm in diameter with a mean specific surface area of about 1,000 m(2) g(-1) and it competes effectively with transferrin for Al(III) binding. Aluminum binding to HSP strongly inhibited its decomposition whilst the reaction rate constant for the formation of the β-silicomolybdic acid complex indicated a diameter between 3.6 and 4.1 nm for these aluminum-containing nanoparticles. Similarly, high resolution microscopic analysis of the air dried aluminum-containing silica colloid solution revealed 3.9 ± 1.3 nm sized crystalline Al-rich silica nanoparticles (ASP) with an estimated Al:Si ratio of between 2 and 3 which is close to the range of secondary aluminosilicates such as imogolite. Thus the high-aluminum-affinity silica polymer is a nanoparticle that seeds early aluminosilicate formation through highly competitive binding of Al(III) ions. In niche environments, especially in vivo, this may serve as an alternative mechanism to polyhydroxy Al(III) species binding monomeric silica to form early phase, non-toxic aluminosilicates.

  20. High-Aluminum-Affinity Silica Is a Nanoparticle That Seeds Secondary Aluminosilicate Formation

    PubMed Central

    Jugdaohsingh, Ravin; Brown, Andy; Dietzel, Martin; Powell, Jonathan J.

    2013-01-01

    Despite the importance and abundance of aluminosilicates throughout our natural surroundings, their formation at neutral pH is, surprisingly, a matter of considerable debate. From our experiments in dilute aluminum and silica containing solutions (pH ~ 7) we previously identified a silica polymer with an extraordinarily high affinity for aluminium ions (high-aluminum-affinity silica polymer, HSP). Here, further characterization shows that HSP is a colloid of approximately 2.4 nm in diameter with a mean specific surface area of about 1,000 m2 g-1 and it competes effectively with transferrin for Al(III) binding. Aluminum binding to HSP strongly inhibited its decomposition whilst the reaction rate constant for the formation of the β-silicomolybdic acid complex indicated a diameter between 3.6 and 4.1 nm for these aluminum-containing nanoparticles. Similarly, high resolution microscopic analysis of the air dried aluminum-containing silica colloid solution revealed 3.9 ± 1.3 nm sized crystalline Al-rich silica nanoparticles (ASP) with an estimated Al:Si ratio of between 2 and 3 which is close to the range of secondary aluminosilicates such as imogolite. Thus the high-aluminum-affinity silica polymer is a nanoparticle that seeds early aluminosilicate formation through highly competitive binding of Al(III) ions. In niche environments, especially in vivo, this may serve as an alternative mechanism to polyhydroxy Al(III) species binding monomeric silica to form early phase, non-toxic aluminosilicates. PMID:24349573

  1. 3rd hand smoking; heterogeneous oxidation of nicotine and secondary aerosol formation in the indoor environment

    NASA Astrophysics Data System (ADS)

    Petrick, Lauren; Dubowski, Yael

    2010-05-01

    Tobacco smoking is well known as a significant source of primary indoor air pollutants. However, only recently has it been recognized that the impact of Tobacco smoking may continue even after the cigarette has been extinguished (i.e., third hand smoke) due to the effect of indoor surfaces. These surfaces may affect the fate of tobacco smoke in the form of secondary reactions and pollutants, including secondary organic aerosol (SOA) formation. Fourier Transform Infrared spectrometry with Attenuated Total Reflection (FTIR-ATR) in tandem with a Scanning Mobility Particle Sizing (SMPS) system was used to monitor the ozonation of cellulose sorbed nicotine and resulting SOA formation. SOA formation began at onset of ozone introduction ([O3] = 60 ± 5 ppb) with a size distribution of dp ≤ 25 nm, and was determined to be a result of heterogeneous reaction (opposed to homogeneous). SOA yield from reacted surface nicotine was on the order of 10 %. Simultaneous to SOA monitoring, FTIR-ATR spectra showed surface changes in the nicotine film as the reaction progressed, revealing a pseudo first-order surface reaction rate of 0.0026 ± 0.0008 min-1. Identified surface oxidation products included: cotinine, myosmine, methylnicotinamide and nicotyrine. Surface reaction rate was found to be partially inhibited at high relative humidity. Given the toxicity of some of the identified products (e.g., cotinine has shown potential mutagenicity and teratogenicity) and that small particles may contribute to adverse health effects, the present study indicates that exposure to 3rd hand smoke ozonation products may pose additional health risks.

  2. Cardiovascular hoarseness: an unusual presentation to otolaryngologists.

    PubMed

    Fennessy, B G; Sheahan, P; McShane, D

    2008-03-01

    We discuss the case of a 73-year-old woman with a six-month history of hoarseness secondary to an aortic arch pseudoaneurysm. We present the findings of an extensive review of the literature relating to cardiovascular disorders involving the recurrent laryngeal nerve (i.e. Ortner's syndrome). Ortner's syndrome, also known as cardiovocal syndrome, is a rare condition, with few reports in the literature. This is only the second documented case of Ortner's syndrome in Great Britain and Ireland, and the first demonstrating an aortic pseudoaneurysm.

  3. Renal Arterial Pseudoaneurysm and Renal Arteriovenous Fistula Following Partial Nephrectomy.

    PubMed

    Chen, Jinchao; Yang, Min; Wu, Pengjie; Li, Teng; Ning, Xianghui; Peng, Shuanghe; Wang, Jiangyi; Qi, Nienie; Gong, Kan

    2018-01-01

    Renal arterial pseudoaneurysm (RAP) and renal arteriovenous fistula (RAVF) are rare but can cause fatal bleeding. A retrospective review was conducted for patients undergoing partial nephrectomy (PN) in our department. The clinical features and treatment methods were analysed, and the relationships between RAP/RAVF and the surgical methods and R.E.N.A.L. score were investigated. Eleven patients were diagnosed with RAP/RAVF (9 with RAP and 2 with RAVF). The incidence of RAP/RAVF after laparoscopic PN showed no significant difference compared to that after open PN (p = 0.47). A low R.E.N.A.L. score was present in 6 patients, while an intermediate/high score was present in the other 5 patients. The major clinical manifestations included haematuria and haemorrhagic shock, and the median time of occurrence was 8 days after the operation. Six patients underwent an ultrasound examination. Of the 4 patients who underwent enhanced CT, 2 patients were diagnosed with RAP. All 11 patients were diagnosed by renal angiography and were cured after super-selective arterial embolization. The serum creatinine levels before and after embolization showed no significant differences (p = 0.14). RAP/RAVF may not have any relationship with the surgical procedure or R.E.N.A.L. score. Renal angiography and super-selective arterial embolization are the preferred methods for diagnosing and treating RAP/RAVF. © 2016 S. Karger AG, Basel.

  4. A model of formative assessment practice in secondary science classrooms using an audience response system

    NASA Astrophysics Data System (ADS)

    Shirley, Melissa L.

    Formative assessment involves the probing of students' ideas to determine their level of understanding during the instructional sequence. Often conceptualized as a cycle, formative assessment consists of the teacher posing an instructional task to students, collecting data about student understanding, and engaging in follow-up strategies such as clarifying student understanding and adjusting instruction to meet learning needs. Despite having been shown to increase student achievement in a variety of classroom settings, formative assessment remains a relative weak area of teacher practice. Methods that enhance formative assessment strategies may therefore have a positive effect on student achievement. Audience response systems comprise a broad category of technologies that support richer classroom interaction and have the potential to facilitate formative assessment. Results from a large national research study, Classroom Connectivity in Promoting Mathematics and Science Achievement (CCMS), show that students in algebra classrooms where the teacher has implemented a type of audience response system experience significantly higher achievement gains compared to a control group. This suggests a role for audience response systems in promoting rich formative assessment. The importance of incorporating formative assessment strategies into regular classroom practice is widely recognized. However, it remains challenging to identify whether rich formative assessment is occurring during a particular class session. This dissertation uses teacher interviews and classroom observations to develop a fine-grained model of formative assessment in secondary science classrooms employing a type of audience response system. This model can be used by researchers and practitioners to characterize components of formative assessment practice in classrooms. A major component of formative assessment practice is the collection and aggregation of evidence of student learning. This dissertation

  5. Light-absorbing oligomer formation in secondary organic aerosol from reactive uptake of isoprene epoxydiols.

    PubMed

    Lin, Ying-Hsuan; Budisulistiorini, Sri Hapsari; Chu, Kevin; Siejack, Richard A; Zhang, Haofei; Riva, Matthieu; Zhang, Zhenfa; Gold, Avram; Kautzman, Kathryn E; Surratt, Jason D

    2014-10-21

    Secondary organic aerosol (SOA) produced from reactive uptake and multiphase chemistry of isoprene epoxydiols (IEPOX) has been found to contribute substantially (upward of 33%) to the fine organic aerosol mass over the Southeastern U.S. Brown carbon (BrC) in rural areas of this region has been linked to secondary sources in the summer when the influence of biomass burning is low. We demonstrate the formation of light-absorbing (290 < λ < 700 nm) SOA constituents from reactive uptake of trans-β-IEPOX onto preexisting sulfate aerosols as a potential source of secondary BrC. IEPOX-derived BrC generated in controlled chamber experiments under dry, acidic conditions has an average mass absorption coefficient of ∼ 300 cm(2) g(-1). Chemical analyses of SOA constituents using UV-visible spectroscopy and high-resolution mass spectrometry indicate the presence of highly unsaturated oligomeric species with molecular weights separated by mass units of 100 (C5H8O2) and 82 (C5H6O) coincident with the observations of enhanced light absorption, suggesting such oligomers as chromophores, and potentially explaining one source of humic-like substances (HULIS) ubiquitously present in atmospheric aerosol. Similar light-absorbing oligomers were identified in fine aerosol collected in the rural Southeastern U.S., supporting their atmospheric relevance and revealing a previously unrecognized source of oligomers derived from isoprene that contributes to ambient fine aerosol mass.

  6. Pulmonary Artery Aneurysm/Pseudoaneurysm, a Delayed Complication of Lung Abscess: A Case Report.

    PubMed

    Oguma, Tsuyoshi; Morise, Masahiro; Harada, Kazuki; Tanaka, Jun; Sato, Masako; Horio, Yukihiro; Takiguchi, Hiroto; Tomomatsu, Hiromi; Tomomatsu, Katsuyoshi; Takihara, Takahisa; Niimi, Kyoko; Hayama, Naoki; Aoki, Takuya; Urano, Tetsuya; Ito, Chihiro; Koizumi, Jun; Asano, Koichiro

    2015-09-20

    Massive hemoptysis mostly arises from the bronchial arteries; however, bleeding can also occur from a lesion in injured pulmonary arteries, such as pulmonary artery aneurysm/pseudoaneurysm (PAA/PAP), during pulmonary infection. A 66-year-old man was admitted with a diagnosis of lung abscess in the right lower lobe that was complicated with pyothorax. Intravenous administration of antibiotics and thoracic drainage successfully controlled the infection and inflammation until day 16, when the patient began to exhibit hemoptysis and bloody pleural effusion. Enhanced computed tomography (CT) with multi-planer reconstruction (MPR) images showed a highly enhanced mass inside the abscess fed by the pulmonary artery, suggesting PAA/PAP. Pulmonary angiography confirmed PAA/PAP, and embolization with coils successfully stopped both the bleeding into the sputum and pleural effusion, with a collapsed aneurysm visible on chest CT scan. Clinicians should consider the possibility of PAA/PAP in the differential diagnosis of hemoptysis during the treatment of patients with lung abscess. MPR CT is helpful for the diagnosis of PAA/PAP and its feeding vessels.

  7. Ozonolysis of a series of biogenic organic volatile compounds and secondary organic aerosol formation

    NASA Astrophysics Data System (ADS)

    Bernard, François; Quilgars, Alain; Cazaunau, Mathieu; Grosselin, Benoît.; Daele, Véronique; Mellouki, Abdelwahid; Winterhalter, Richard; Moortgat, Geert K.

    2010-05-01

    Secondary organic aerosols are formed via nucleation of atmospheric organic vapours on pre-existing particles observed in various rural environments where the organic fraction represents the major part of the observed nano-particle (Kavouras and Stephanou, 2002; Kulmala et al., 2004a). However, nucleation of organic vapors appears to be unlikely thermodynamically in relevant atmospheric conditions (Kulmala et al., 2004b). In this work, a systematic study has been conducted to investigate the aerosol formation through the ozonolysis of a series of monotepenes using a newly developed aerosol flow reactor and the ICARE indoor simulation chamber. The nucleation thresholds have been determined for SOA formed through the reaction of ozone with a-Pinene, sabinene, myrcene and limonene in absence of any observable existing particles. The measurements were performed using the flow reactor combined to a particle counter (CPC 3022). Number concentrations of SOA have been measured for different concentration of consumed monoterpenes. The data obtained allow us to estimate the nucleation threshold for a range of 0.2 - 45 ppb of consumed monoterpenes. The nucleation threshold values obtained here (≤ 1 ppb of the consumed monoterpenes) have been found to be lower than the previously reported ones (Berndt et al., 2003; Bonn and Moortgat, 2003; Koch et al., 2000; Lee and Kamens, 2005). The ICARE simulation chamber has been used to study the mechanism of the reaction of ozone with various acyclic terpenes (myrcene, ocimene, linalool and a-farnesene) and to derive the SOA mass formation yield. The time-concentration profiles of reactants and products in gas-phase were obtained using in-situ Fourier Transform Infrared Spectroscopy. In addition, the number and mass concentrations of SOA have been monitored with a Scanning Mobility Particle Sizer. The chemical composition of the SOA formed has been tentatively characterised using Liquid Chromatography - Mass Spectrometry. The results

  8. New positive feedback mechanism between boundary layer meteorology and secondary aerosol formation during severe haze events.

    PubMed

    Liu, Quan; Jia, Xingcan; Quan, Jiannong; Li, Jiayun; Li, Xia; Wu, Yongxue; Chen, Dan; Wang, Zifa; Liu, Yangang

    2018-04-17

    Severe haze events during which particulate matter (PM) increases quickly from tens to hundreds of microgram per cubic meter in 1-2 days frequently occur in China. Although it has been known that PM is influenced by complex interplays among emissions, meteorology, and physical and chemical processes, specific mechanisms remain elusive. Here, a new positive feedback mechanism between planetary boundary layer (PBL), relative humidity (RH), and secondary PM (SPM) formation is proposed based on a comprehensive field experiment and model simulation. The decreased PBL associated with increased PM increases RH by weakening the vertical transport of water vapor; the increased RH in turn enhances the SPM formation through heterogeneous aqueous reactions, which further enhances PM, weakens solar radiation, and decreases PBL height. This positive feedback, together with the PM-Radiation-PBL feedback, constitutes a key mechanism that links PM, radiation, PBL properties (e.g. PBL height and RH), and SPM formation, This mechanism is self-amplifying, leading to faster PM production, accumulation, and more severe haze pollution.

  9. Modeling Secondary Organic Aerosol Formation From Emissions of Combustion Sources

    NASA Astrophysics Data System (ADS)

    Jathar, Shantanu Hemant

    Atmospheric aerosols exert a large influence on the Earth's climate and cause adverse public health effects, reduced visibility and material degradation. Secondary organic aerosol (SOA), defined as the aerosol mass arising from the oxidation products of gas-phase organic species, accounts for a significant fraction of the submicron atmospheric aerosol mass. Yet, there are large uncertainties surrounding the sources, atmospheric evolution and properties of SOA. This thesis combines laboratory experiments, extensive data analysis and global modeling to investigate the contribution of semi-volatile and intermediate volatility organic compounds (SVOC and IVOC) from combustion sources to SOA formation. The goals are to quantify the contribution of these emissions to ambient PM and to evaluate and improve models to simulate its formation. To create a database for model development and evaluation, a series of smog chamber experiments were conducted on evaporated fuel, which served as surrogates for real-world combustion emissions. Diesel formed the most SOA followed by conventional jet fuel / jet fuel derived from natural gas, gasoline and jet fuel derived from coal. The variability in SOA formation from actual combustion emissions can be partially explained by the composition of the fuel. Several models were developed and tested along with existing models using SOA data from smog chamber experiments conducted using evaporated fuel (this work, gasoline, fischertropschs, jet fuel, diesels) and published data on dilute combustion emissions (aircraft, on- and off-road gasoline, on- and off-road diesel, wood burning, biomass burning). For all of the SOA data, existing models under-predicted SOA formation if SVOC/IVOC were not included. For the evaporated fuel experiments, when SVOC/IVOC were included predictions using the existing SOA model were brought to within a factor of two of measurements with minor adjustments to model parameterizations. Further, a volatility

  10. Effect of Pellet Boiler Exhaust on Secondary Organic Aerosol Formation from α-Pinene.

    PubMed

    Kari, Eetu; Hao, Liqing; Yli-Pirilä, Pasi; Leskinen, Ari; Kortelainen, Miika; Grigonyte, Julija; Worsnop, Douglas R; Jokiniemi, Jorma; Sippula, Olli; Faiola, Celia L; Virtanen, Annele

    2017-02-07

    Interactions between anthropogenic and biogenic emissions, and implications for aerosol production, have raised particular scientific interest. Despite active research in this area, real anthropogenic emission sources have not been exploited for anthropogenic-biogenic interaction studies until now. This work examines these interactions using α-pinene and pellet boiler emissions as a model test system. The impact of pellet boiler emissions on secondary organic aerosol (SOA) formation from α-pinene photo-oxidation was studied under atmospherically relevant conditions in an environmental chamber. The aim of this study was to identify which of the major pellet exhaust components (including high nitrogen oxide (NO x ), primary particles, or a combination of the two) affected SOA formation from α-pinene. Results demonstrated that high NO x concentrations emitted by the pellet boiler reduced SOA yields from α-pinene, whereas the chemical properties of the primary particles emitted by the pellet boiler had no effect on observed SOA yields. The maximum SOA yield of α-pinene in the presence of pellet boiler exhaust (under high-NO x conditions) was 18.7% and in the absence of pellet boiler exhaust (under low-NO x conditions) was 34.1%. The reduced SOA yield under high-NO x conditions was caused by changes in gas-phase chemistry that led to the formation of organonitrate compounds.

  11. Formation of secondary organic aerosol in the Paris pollution plume and its impact on surrounding regions

    NASA Astrophysics Data System (ADS)

    Zhang, Q. J.; Beekmann, M.; Freney, E.; Sellegri, K.; Pichon, J. M.; Schwarzenboeck, A.; Colomb, A.; Bourrianne, T.; Michoud, V.; Borbon, A.

    2015-12-01

    Secondary pollutants such as ozone, secondary inorganic aerosol, and secondary organic aerosol formed in the plumes of megacities can affect regional air quality. In the framework of the FP7/EU MEGAPOLI (Megacities: Emissions, urban, regional and Global Atmospheric POLlution and climate effects, and Integrated tools for assessment and mitigation) project, an intensive campaign was launched in the greater Paris region in July 2009. The major objective was to quantify different sources of organic aerosol (OA) within a megacity and in its plume. In this study, we use airborne measurements aboard the French ATR-42 aircraft to evaluate the regional chemistry-transport model CHIMERE within and downwind of the Paris region. Two mechanisms of secondary OA (SOA) formation are used, both including SOA formation from oxidation and chemical aging of primary semivolatile and intermediate volatility organic compounds (SI-SOA) in the volatility basis set (VBS) framework. As for SOA formed from traditional VOC (volatile organic compound) precursors (traditional SOA), one applies chemical aging in the VBS framework adopting different SOA yields for high- and low-NOx environments, while another applies a single-step oxidation scheme without chemical aging. Two emission inventories are used for discussion of emission uncertainties. The slopes of the airborne OA levels versus Ox (i.e., O3 + NO2) show SOA formation normalized with respect to photochemical activity and are used for specific evaluation of the OA scheme in the model. The simulated slopes were overestimated slightly by factors of 1.1, 1.7 and 1.3 with respect to those observed for the three airborne measurements, when the most realistic "high-NOx" yields for traditional SOA formation in the VBS scheme are used in the model. In addition, these slopes are relatively stable from one day to another, which suggests that they are characteristic for the given megacity plume environment. The configuration with increased primary

  12. Use of Pipeline™ embolization device for the treatment of traumatic intracranial pseudoaneurysms: Case series and review of cases from literature.

    PubMed

    Sami, Mairaj T; Gattozzi, Domenico A; Soliman, Hesham M; Reeves, Alan R; Moran, Christopher J; Camarata, Paul J; Ebersole, Koji C

    2018-06-01

    Intracranial traumatic pseudoaneurysms (PSA) are a rare but dangerous subtype of cerebral aneurysm. Reports documenting use of flow-diverting stents to treat traumatic intracranial PSAs are few and lack long-term follow-up. To our knowledge, this is the largest case-series to date demonstrating use of Pipeline Endovascular Device (PED) for traumatic intracranial PSAs. Retrospective review of 8 intracranial traumatic PSAs in 7 patients treated using only PED placement. Patients were followed clinically and angiographically for at least 6 months. Seven patients with a mean age of 37 years were treated for 8 intracranial pseudo-aneurysms between 2011-2015. Six aneurysms were the result of blunt trauma; 2 were from iatrogenic injury during transsphenoidal surgery. Mean clinical and angiographic follow-up in surviving patients was 15.2 months. In patients with angiographic follow-up, complete occlusion was achieved in all but one patient, who demonstrated near-complete occlusion. No ischemic events or stent-related stenosis were observed. One patient developed a carotid-cavernous fistula after PED, which was successfully retreated with placement of a second PED. There were two mortalities. One was due to suspected microwire perforation remote from the target aneurysm resulting in SAH/IPH. The other was due to a traumatic SDH and brainstem hemorrhage from an unrelated fall during follow-up interval. Use of PED for treatment of intracerebral PSAs following trauma or iatrogenic injury showed good persistent occlusion, and acceptable complication rate for this high-risk pathology. Risks of this procedure and necessary antiplatelet therapy require appropriate patient selection. Larger prospective studies are warranted. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. The Transcriptomics of Secondary Growth and Wood Formation in Conifers

    PubMed Central

    Carvalho, Ana; Paiva, Jorge; Louzada, José; Lima-Brito, José

    2013-01-01

    In the last years, forestry scientists have adapted genomics and next-generation sequencing (NGS) technologies to the search for candidate genes related to the transcriptomics of secondary growth and wood formation in several tree species. Gymnosperms, in particular, the conifers, are ecologically and economically important, namely, for the production of wood and other forestry end products. Until very recently, no whole genome sequencing of a conifer genome was available. Due to the gradual improvement of the NGS technologies and inherent bioinformatics tools, two draft assemblies of the whole genomes sequence of Picea abies and Picea glauca arose in the current year. These draft genome assemblies will bring new insights about the structure, content, and evolution of the conifer genomes. Furthermore, new directions in the forestry, breeding and research of conifers will be discussed in the following. The identification of genes associated with the xylem transcriptome and the knowledge of their regulatory mechanisms will provide less time-consuming breeding cycles and a high accuracy for the selection of traits related to wood production and quality. PMID:24288610

  14. Laboratory studies of monoterpene secondary organic aerosol formation and evolution

    NASA Astrophysics Data System (ADS)

    Thornton, J. A.; D'Ambro, E.; Zhao, Y.; Lee, B. H.; Pye, H. O. T.; Schobesberger, S.; Shilling, J.; Liu, J.

    2017-12-01

    We have conducted a series of chamber experiments to study the molecular composition and properties of secondary organic aerosol (SOA) formed from monoterpenes under a range of photochemical and dark conditions. We connect variations in the SOA mass yield to molecular composition and volatility, and use a detailed Master Chemical Mechanism (MCM) based chemical box model with dynamic gas-particle partitioning to examine the importance of various peroxy radical reaction mechanisms in setting the SOA yield and properties. We compare the volatility distribution predicted by the model to that inferred from isothermal room-temperature evaporation experiments using the FIGAERO-CIMS where SOA particles collected on a filter are allowed to evaporate under humidified pure nitrogen flow stream for up to 24 hours. We show that the combination of results requires prompt formation of low volatility SOA from predominantly gas-phase mechanisms, with important differences between monoterpenes (alpha-Pinene and delta-3-Carene) followed by slower non-radical particle phase chemistry that modulates both the chemical and physical properties of the SOA. Implications for the regional evolution of atmospheric monoterpene SOA are also discussed.

  15. Some aspects of the problem of secondary eyewall formation in idealized three-dimensional nonlinear simulations

    NASA Astrophysics Data System (ADS)

    Menelaou, K.; Yau, M. K.; Martinez, Y.

    2014-09-01

    Some aspects of the problem of secondary eyewall formation (SEF) are investigated with the aid of an idealized model. A series of experiments are conducted, starting with a strong annular vortex embedded in a quiescent background flow and forced by the sustained heating associated with a spiral rainband (control experiment). Following this, two experiments are configured to assess the impact of vertical wind shear (VWS) in the SEF process. The importance of the boundary layer force imbalance is finally investigated in a number of simulations in which surface and boundary layer physics are included. From the control experiment, it is found that in the absence of background environmental flow, the sustained latent heating associated with a spiral rainband can form a secondary eyewall even in the absence of a frictional boundary layer. The presence of VWS acts negatively in the SEF process by disrupting the organization of the potential vorticity induced by the rainband. When boundary layer physics is included, some similarities with previous studies are seen, but there is no SEF. These results suggest that the boundary layer most likely contributes to, rather than initiate, a secondary eyewall. This article was corrected on 10 OCT 2014. See the end of the full text for details.

  16. Vascular Complications of Pancreatitis: Role of Interventional Therapy

    PubMed Central

    Lopera, Jorge E.

    2012-01-01

    Major vascular complications related to pancreatitis can cause life-threatening hemorrhage and have to be dealt with as an emergency, utilizing a multidisciplinary approach of angiography, endoscopy or surgery. These may occur secondary to direct vascular injuries, which result in the formation of splanchnic pseudoaneurysms, gastrointestinal etiologies such as peptic ulcer disease and gastroesophageal varices, and post-operative bleeding related to pancreatic surgery. In this review article, we discuss the pathophysiologic mechanisms, diagnostic modalities, and treatment of pancreatic vascular complications, with a focus on the role of minimally-invasive interventional therapies such as angioembolization, endovascular stenting, and ultrasound-guided percutaneous thrombin injection in their management. PMID:22563287

  17. Nonequilibrium atmospheric secondary organic aerosol formation and growth

    PubMed Central

    Perraud, Véronique; Bruns, Emily A.; Ezell, Michael J.; Johnson, Stanley N.; Yu, Yong; Alexander, M. Lizabeth; Zelenyuk, Alla; Imre, Dan; Chang, Wayne L.; Dabdub, Donald; Pankow, James F.; Finlayson-Pitts, Barbara J.

    2012-01-01

    Airborne particles play critical roles in air quality, health effects, visibility, and climate. Secondary organic aerosols (SOA) formed from oxidation of organic gases such as α-pinene account for a significant portion of total airborne particle mass. Current atmospheric models typically incorporate the assumption that SOA mass is a liquid into which semivolatile organic compounds undergo instantaneous equilibrium partitioning to grow the particles into the size range important for light scattering and cloud condensation nuclei activity. We report studies of particles from the oxidation of α-pinene by ozone and NO3 radicals at room temperature. SOA is primarily formed from low-volatility ozonolysis products, with a small contribution from higher volatility organic nitrates from the NO3 reaction. Contrary to expectations, the particulate nitrate concentration is not consistent with equilibrium partitioning between the gas phase and a liquid particle. Rather the fraction of organic nitrates in the particles is only explained by irreversible, kinetically determined uptake of the nitrates on existing particles, with an uptake coefficient that is 1.6% of that for the ozonolysis products. If the nonequilibrium particle formation and growth observed in this atmospherically important system is a general phenomenon in the atmosphere, aerosol models may need to be reformulated. The reformulation of aerosol models could impact the predicted evolution of SOA in the atmosphere both outdoors and indoors, its role in heterogeneous chemistry, its projected impacts on air quality, visibility, and climate, and hence the development of reliable control strategies. PMID:22308444

  18. COP9 signalosome subunit PfCsnE regulates secondary metabolism and conidial formation in Pestalotiopsis fici.

    PubMed

    Zheng, Yanjing; Wang, Xiuna; Zhang, Xiaoling; Li, Wei; Liu, Gang; Wang, Shihua; Yan, Xiufeng; Zou, Huixi; Yin, Wen-Bing

    2017-06-01

    The COP9 signalosome (CSN) is a highly conserved multiprotein complex in all eukaryotes and involved in regulation of organism development. In filamentous fungi, several lines of evidence indicate that fungal development and secondary metabolism (SM) are mediated by the fifth subunit of CSN, called CsnE. Here we uncover a connection with CsnE and conidial formation as well as SM regulation in the plant endophytic fungus Pestalotiopsis fici. A homology search of the P. fici genome with CsnE, involved in sexual development and SM in Aspergillus nidulans, identified PfCsnE. Deletion of PfcsnE resulted in a mutant that stopped conidial production, but the conidia are recovered in a PfcsnE complemented strain. This indicates that PfCsnE is required for the formation of conidia. Secondary metabolite analysis demonstrated that the ΔPfcsnE strain produced more chloroisosulochrin, less ficiolide A production in comparison to wild type (WT). Transcriptome analysis of WT and ΔPfcsnE strains indicated that PfcsnE impacts the expression levels of 8.37% of 14,797 annotated genes. Specifically, nine biosynthetic gene clusters (BGCs) were up-regulated and three BGCs were down-regulated by PfCsnE. Our results suggest that PfCsnE plays major roles in SM regulation and conidial development in P. fici.

  19. Using fluorescence-parallel factor analysis for assessing disinfection by-product formation and natural organic matter removal efficiency in secondary treated synthetic drinking waters.

    PubMed

    Watson, Kalinda; Farré, Maria José; Leusch, Frederic D L; Knight, Nicole

    2018-05-28

    Parallel factor (PARAFAC) analysis of fluorescence excitation-emission matrices (EEMs) was used to investigate the organic matter and DBP formation characteristics of untreated, primary treated (enhanced coagulation; EC) and secondary treated synthetic waters prepared using a Suwannee River natural organic matter (SR-NOM) isolate. The organic matter was characterised by four different fluorescence components; two humic acid-like (C1 and C2) and two protein-like (C3 and C4). Secondary treatment methods tested, following EC treatment, were; powdered activated carbon (PAC), granular activated carbon (GAC), 0.1% silver-impregnated activated carbon (SIAC), and MIEX® resin. Secondary treatments were more effective at removing natural organic matter (NOM) and fluorescent DBP-precursor components than EC alone. The formation of a suite of 17 DBPs including chlorinated, brominated and iodinated trihalomethanes (THMs), dihaloacetonitriles (DHANs), chloropropanones (CPs), chloral hydrate (CH) and trichloronitromethane (TCNM) was determined after chlorinating water sampled before and after each treatment step. Regression analysis was used to investigate the relationship between peak component fluorescence intensity (F MAX ), DBP concentration and speciation, and more commonly used aggregate parameters such as DOC, UV 254 and SUVA 254 . PARAFAC component 1 (C1) was in general a better predictor of DBP formation than other aggregate parameters, and was well correlated (R ≥ 0.80) with all detected DBPs except dibromochloromethane (DBCM) and dibromoacetonitrile (DBAN). These results indicate that the fluorescence-PARAFAC approach could provide a robust analytical tool for predicting DBP formation, and for evaluating the removal of NOM fractions relevant to DBP formation during water treatment. Copyright © 2018. Published by Elsevier B.V.

  20. Secondary organic aerosol formation from hydroxyl radical oxidation and ozonolysis of monoterpenes

    NASA Astrophysics Data System (ADS)

    Zhao, D. F.; Kaminski, M.; Schlag, P.; Fuchs, H.; Acir, I.-H.; Bohn, B.; Häseler, R.; Kiendler-Scharr, A.; Rohrer, F.; Tillmann, R.; Wang, M. J.; Wegener, R.; Wildt, J.; Wahner, A.; Mentel, Th. F.

    2015-01-01

    Oxidation by hydroxyl radical (OH) and ozonolysis are the two major pathways of daytime biogenic volatile organic compound (BVOC) oxidation and secondary organic aerosol (SOA) formation. In this study, we investigated the particle formation of several common monoterpenes (α-pinene, β-pinene and limonene) by OH-dominated oxidation, which has seldom been investigated. OH oxidation experiments were carried out in the SAPHIR (Simulation of Atmospheric PHotochemistry In a large Reaction) chamber in Jülich, Germany, at low NOx (0.01 ~ 1 ppbV) and low ozone (O3) concentration (< 20 ppbV). OH concentration and total OH reactivity (kOH) were measured directly, and through this the overall reaction rate of total organics with OH in each reaction system was quantified. Multi-generation reaction process, particle growth, new particle formation (NPF), particle yield and chemical composition were analyzed and compared with that of monoterpene ozonolysis. Multi-generation products were found to be important in OH-dominated SOA formation. The relative role of functionalization and fragmentation in the reaction process of OH oxidation was analyzed by examining the particle mass and the particle size as a function of OH dose. We developed a novel method which quantitatively links particle growth to the reaction rate of OH with total organics in a reaction system. This method was also used to analyze the evolution of functionalization and fragmentation of organics in the particle formation by OH oxidation. It shows that functionalization of organics was dominant in the beginning of the reaction (within two lifetimes of the monoterpene) and fragmentation started to play an important role after that. We compared particle formation from OH oxidation with that from pure ozonolysis. In individual experiments, growth rates of the particle size did not necessarily correlate with the reaction rate of monoterpene with OH and O3. Comparing the size growth rates at the similar reaction rates

  1. Investigating the Relative Contributions of Secondary Ice Formation Processes to Ice Crystal Number Concentrations Within Mixed-Phase Clouds

    NASA Astrophysics Data System (ADS)

    Sullivan, S.; Nenes, A.

    2015-12-01

    Measurements of the in-cloud ice nuclei concentration can be three or four orders of magnitude less than those of the in-cloud ice crystal number concentration. Different secondary formation processes, active after initial ice nucleation, have been proposed to explain this discrepancy, but their relative importance, and even the exact physics of each mechanism, are still unclear. We construct a simple bin microphysics model (2IM) including depositional growth, the Hallett-Mossop process, ice-ice collisions, and ice-ice aggregation, with temperature- and supersaturation-dependent efficiencies for each process. 2IM extends the time-lag collision model of Yano and Phillips to additional bins and incorporates the aspect ratio evolution of Jensen and Harrington. Model output and measured ice crystal size distributions are compared to answer three questions: (1) how important is ice-ice aggregation relative to ice-ice collision around -15°C, where the Hallett-Mossop process is no longer active; (2) what process efficiencies lead to the best reproduction of observed ice crystal size distributions; and (3) does ice crystal aspect ratio affect the dominant secondary formation process. The resulting parameterization is intended for eventual use in larger-scale mixed-phase cloud schemes.

  2. Direct Observations of Isoprene Secondary Organic Aerosol Formation in Ambient Cloud Droplets

    NASA Astrophysics Data System (ADS)

    Zelenyuk, A.; Bell, D.; Thornton, J. A.; Fast, J. D.; Shrivastava, M. B.; Berg, L. K.; Imre, D. G.; Mei, F.; Shilling, J.; Suski, K. J.; Liu, J.; Tomlinson, J. M.; Wang, J.

    2017-12-01

    Multiphase chemistry of isoprene photooxidation products has been shown to be one of the major sources of secondary organic aerosol (SOA) in the atmosphere. A number of recent studies indicate that aqueous aerosol phase provides a medium for reactive uptake of isoprene photooxidation products, and in particular, isomeric isoprene epoxydiols (IEPOX), with reaction rates and yields being dependent on aerosol acidity, water content, sulfate concentration, and organic coatings. However, very few studies focused on chemistry occurring within actual cloud droplets. We will present data acquired during recent Holistic Interactions of Shallow Clouds, Aerosols, and Land Ecosystems (HI-SCALE) Campaign, which provide direct evidence for IEPOX-SOA formation in cloud droplets. Single particle mass spectrometer, miniSPLAT, and a high-resolution, time-of-flight aerosol mass spectrometer were used to characterize the composition of aerosol particles and cloud droplet residuals, while a high-resolution, time-of-flight chemical ionization mass spectrometer (HR-ToF-CIMS) was used to characterize gas-phase compounds. We find that the composition of cloud droplet residuals was markedly different than that of aerosol particles sampled outside the cloud. Cloud droplet residuals were comprised of individual particles with high relative fractions of sulfate and nitrate and significant fraction of particles with mass spectra that are nearly identical to those of laboratory-generated IEPOX-SOA particles. The observed cloud-induced formation of IEPOX-SOA was accompanied by simultaneous decrease in measured concentrations of IEPOX and other gas-phase isoprene photooxidation products. Ultimately, the combined cloud, aerosol, and gas-phase measurements conducted during HI-SCALE will be used to develop and evaluate model treatments of aqueous-phase isoprene SOA formation.

  3. New positive feedback mechanism between boundary layer meteorology and secondary aerosol formation during severe haze events

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Liu, Quan; Jia, Xingcan; Quan, Jiannong

    Severe haze events during which particulate matter (PM) increases quickly from tens to hundreds of microgram per cubic meter in 1-2 days frequently occur in China. Although it has been known that PM is influenced by complex interplays among emissions, meteorology, and physical and chemical processes, specific mechanisms remain elusive. In this paper, a new positive feedback mechanism between planetary boundary layer (PBL), relative humidity (RH), and secondary PM (SPM) formation is proposed based on a comprehensive field experiment and model simulation. The decreased PBL associated with increased PM increases RH by weakening the vertical transport of water vapor; themore » increased RH in turn enhances the SPM formation through heterogeneous aqueous reactions, which further enhances PM, weakens solar radiation, and decreases PBL height. This positive feedback, together with the PM-Radiation-PBL feedback, constitutes a key mechanism that links PM, radiation, PBL properties (e.g. PBL height and RH), and SPM formation, This mechanism is self-amplifying, leading to faster PM production, accumulation, and more severe haze pollution.« less

  4. New positive feedback mechanism between boundary layer meteorology and secondary aerosol formation during severe haze events

    DOE PAGES

    Liu, Quan; Jia, Xingcan; Quan, Jiannong; ...

    2018-04-17

    Severe haze events during which particulate matter (PM) increases quickly from tens to hundreds of microgram per cubic meter in 1-2 days frequently occur in China. Although it has been known that PM is influenced by complex interplays among emissions, meteorology, and physical and chemical processes, specific mechanisms remain elusive. In this paper, a new positive feedback mechanism between planetary boundary layer (PBL), relative humidity (RH), and secondary PM (SPM) formation is proposed based on a comprehensive field experiment and model simulation. The decreased PBL associated with increased PM increases RH by weakening the vertical transport of water vapor; themore » increased RH in turn enhances the SPM formation through heterogeneous aqueous reactions, which further enhances PM, weakens solar radiation, and decreases PBL height. This positive feedback, together with the PM-Radiation-PBL feedback, constitutes a key mechanism that links PM, radiation, PBL properties (e.g. PBL height and RH), and SPM formation, This mechanism is self-amplifying, leading to faster PM production, accumulation, and more severe haze pollution.« less

  5. Percutaneous trans-hepatic gelfoam-cyanoacrylate glue embolization for ruptured post-traumatic hepatic artery pseudo-aneurysm in a limited-resource scenario.

    PubMed

    Kumar, Manoj; Goel, Prabudh; Rawat, J D; Kumari, Shweta; Shankhwar, S N; Kureel, S N

    2013-05-01

    We present our experience with an indigenously designed percutaneous trans-hepatic ultrasound-guided Gelfoam sponge cum cyanoacrylate glue-based embolization technique for the treatment of a ruptured post-traumatic aneurysm of a branch of the right hepatic artery (RHA) as a 'life-saving emergent' procedure in a patient unfit for surgery or endovascular intervention and in a 'limited-resource' scenario (non-availability of Digital Subtraction Angiography Suite). An 8-year-old boy sustained crush-injury to the right lobe of the liver in a road-traffic accident and presented in shock. After resuscitation, a laparotomy and repair of the right lobe of liver were undertaken. Bleeding restarted 1 week after the surgery; the patient bled from drain site and went into shock. Exploration was not advisable in view of poor general condition, and sepsis, deranged coagulation and parental reluctance in view of guarded prognosis. Multi-detector Computed Tomography Angiography was performed after resuscitation which revealed active bleed from a ruptured pseudo-aneurysm of a branch of RHA. The bleeding artery was identified with duplex sonography and was embolized by the percutaneous trans-hepatic route proximal to the site of pseudo-aneurysm and rupture by a two-step process. Initially, a thin paste/'slurry' made of powdered gelfoam dissolved in sterile saline was injected into the bleeding vessel. Subsequently, the area was sealed by injecting 1.0 ml of N-butyl-2-cyanoacrylate glue. Hemostasis was confirmed by Color and Power Doppler Ultrasonography both post-procedure and after 48 h. With supportive management, the patient showed a rapid recovery and was discharged after 2 weeks. He continues to be well at 3-month follow-up. The technique was effective in controlling hemostasis and life-saving in our set-up.

  6. Secondary inorganic aerosols formation during haze episodes at an urban site in Beijing, China

    NASA Astrophysics Data System (ADS)

    Zhang, Rui; Sun, Xuesong; Shi, Aijun; Huang, Yuhu; Yan, Jing; Nie, Teng; Yan, Xiao; Li, Xuan

    2018-03-01

    Severe PM2.5 pollution was observed frequently in Beijing. We conducted highly time-resolved measurements of inorganic ions associated with PM2.5 at an urban site in Beijing from 10 February to 19 March, 2015. The average PM2.5 mass concentrations during the six haze episodes ranged from 113.0 μg/m3 to 182.6 μg/m3, which were more than 8 times higher than those observed in clean periods. The secondary inorganic species (NH4+, SO42- and NO3-) in PM2.5 sharply increased during the haze episodes, indicating more extensive formation of SO42- and NO3-. The sulfur oxidation ratios (SOR) and the nitrogen oxidation ratios (NOR) in haze episodes were higher than those in clean periods, which indicated that secondary transformation in haze episodes was more significant than those in clean periods. No correlations between SOR and the oxidants (O3 and HONO) and the temperature were found, whereas a high correlation between SOR and relative humidity (RH) was found in haze episodes, which implied that sulfate was mainly produced by the aqueous-phase oxidation of SO2 rather than the gas-phase conversion of SO2 to sulfate. The conversion of SO2 to SO42- was observed to be sensitive to changes in RH. Furthermore, the SOR sharply increased at RH > 60% with the highest value of 0.88 at RH around 80% during complicated pollution. NO2 played an important role in the rapid sulfate formation with high RH and NH3 neutralization conditions in haze episodes in Beijing. The impact of RH was less apparent for nitrate than for sulfate. Nitrate was found to be produced mainly by photochemical and heterogeneous reactions, while heterogeneous reactions had a greater influence on NOR at nighttime. The NO3-/SO42- ratio indicated that mobile sources contributed more to the formation of PM2.5 than stationary sources. The result suggested the need for control of vehicle emissions to reduce the high levels of NOx and nitrate and the severe PM2.5 pollution in Beijing.

  7. Overview of Nonoperative Blunt Splenic Injury Management with Associated Splenic Artery Pseudoaneurysm.

    PubMed

    Morrison, Chet A; Gross, Brian W; Kauffman, Matthew; Rittenhouse, Katelyn J; Rogers, Frederick B

    2017-06-01

    The delayed development of splenic artery pseudoaneurysm (SAP) can complicate the nonoperative management of splenic injuries. We sought to determine the utility of repeat imaging in diagnosing SAP in patients managed nonoperatively without angioembolization. We hypothesized that a significant rate of SAPs would be found in this population on repeat imaging. Patients undergoing nonoperative splenic injury management from January 2011 to June 2015 were queried from the trauma registry. Rates of repeat imaging, angioembolization, readmission, and SAP development were analyzed. Further, subanalyses investigating the incidence of SAP in patients managed nonoperatively without angioembolization were conducted. A total of 133 patients met inclusion criteria. Repeat imaging rate was 40 per cent, angioembolization rate was 26 per cent, and readmission rate was 6 per cent. Within the study population, nine SAPs were found (8/9 in patients with splenic injury grade ≥III). Of these nine SAPs, three (33%) were identified on initial scans and embolized, whereas six (67%) were found on repeat imaging in patients not initially receiving angioembolization. Splenic injuries are typically managed nonoperatively without serious complications. Our results suggest patients with splenic injuries grade ≥III managed nonoperatively without angioembolization should have repeat imaging within 48 hours to rule out the possibility of SAP.

  8. Limited effect of anthropogenic nitrogen oxides on Secondary Organic Aerosol formation

    NASA Astrophysics Data System (ADS)

    Zheng, Y.; Unger, N.; Hodzic, A.; Emmons, L.; Knote, C.; Tilmes, S.; Lamarque, J.-F.; Yu, P.

    2015-08-01

    Globally, secondary organic aerosol (SOA) is mostly formed from emissions of biogenic volatile organic compounds (VOCs) by vegetation, but can be modified by human activities as demonstrated in recent research. Specifically, nitrogen oxides (NOx = NO + NO2) have been shown to play a critical role in the chemical formation of low volatility compounds. We have updated the SOA scheme in the global NCAR Community Atmospheric Model version 4 with chemistry (CAM4-chem) by implementing a 4-product Volatility Basis Set (VBS) scheme, including NOx-dependent SOA yields and aging parameterizations. The predicted organic aerosol amounts capture both the magnitude and distribution of US surface annual mean measurements from the Interagency Monitoring of Protected Visual Environments (IMPROVE) network by 50 %, and the simulated vertical profiles are within a factor of two compared to Aerosol Mass Spectrometer (AMS) measurements from 13 aircraft-based field campaigns across different region and seasons. We then perform sensitivity experiments to examine how the SOA loading responds to a 50 % reduction in anthropogenic nitric oxide (NO) emissions in different regions. We find limited SOA reductions of 0.9 to 5.6, 6.4 to 12.0 and 0.9 to 2.8 % for global, the southeast US and the Amazon NOx perturbations, respectively. The fact that SOA formation is almost unaffected by changes in NOx can be largely attributed to buffering in chemical pathways (low- and high-NOx pathways, O3 versus NO3-initiated oxidation) and to offsetting tendencies in the biogenic versus anthropogenic SOA responses.

  9. Limited effect of anthropogenic nitrogen oxides on Secondary Organic Aerosol formation

    DOE PAGES

    Zheng, Y.; Unger, N.; Hodzic, A.; ...

    2015-08-28

    Globally, secondary organic aerosol (SOA) is mostly formed from emissions of biogenic volatile organic compounds (VOCs) by vegetation, but can be modified by human activities as demonstrated in recent research. Specifically, nitrogen oxides (NO x = NO + NO 2) have been shown to play a critical role in the chemical formation of low volatility compounds. We have updated the SOA scheme in the global NCAR Community Atmospheric Model version 4 with chemistry (CAM4-chem) by implementing a 4-product Volatility Basis Set (VBS) scheme, including NO x-dependent SOA yields and aging parameterizations. The predicted organic aerosol amounts capture both the magnitudemore » and distribution of US surface annual mean measurements from the Interagency Monitoring of Protected Visual Environments (IMPROVE) network by 50 %, and the simulated vertical profiles are within a factor of two compared to Aerosol Mass Spectrometer (AMS) measurements from 13 aircraft-based field campaigns across different region and seasons. We then perform sensitivity experiments to examine how the SOA loading responds to a 50 % reduction in anthropogenic nitric oxide (NO) emissions in different regions. We find limited SOA reductions of 0.9 to 5.6, 6.4 to 12.0 and 0.9 to 2.8 % for global, the southeast US and the Amazon NO x perturbations, respectively. The fact that SOA formation is almost unaffected by changes in NO x can be largely attributed to buffering in chemical pathways (low- and high-NO x pathways, O 3 versus NO 3-initiated oxidation) and to offsetting tendencies in the biogenic versus anthropogenic SOA responses.« less

  10. Limited Effect of Anthropogenic Nitrogen Oxides on Secondary Organic Aerosol Formation

    NASA Astrophysics Data System (ADS)

    Zheng, Y.; Unger, N.; Hodzic, A.; Knote, C. J.; Tilmes, S.; Emmons, L. K.; Lamarque, J. F.; Yu, P.

    2014-12-01

    Globally secondary organic aerosol (SOA) is mostly formed from biogenic vegetation emissions and as such is regarded as natural aerosol that cannot be reduced by emission control legislation. However, recent research implies that human activities facilitate SOA formation by affecting the amount of precursor emission, the chemical processing and the partitioning into the aerosol phase. Among the multiple human influences, nitrogen oxides (NO + NO2 = NOx) have been assumed to play a critical role in the chemical formation of low volatile compounds. The goal of this study is to improve the SOA scheme in the global NCAR Community Atmospheric Model version 4 with chemistry (CAM4-Chem) by implementing an updated 4-product Volatility Basis Set (VBS) scheme, and apply it to investigate the impact of anthropogenic NOx on SOA. We first compare three different SOA parameterizations: a 2-product model and the updated VBS model both with and without a SOA aging parameterization. Secondly we evaluate predicted organic aerosol amounts against surface measurement from the Interagency Monitoring of Protected Visual Environments (IMPROVE) network and Aerosol Mass Spectrometer (AMS) measurements from 13 aircraft-based field campaigns. We then perform sensitivity experiments to examine how the SOA loading responds to a 50% reduction in anthropogenic NOx in different regions. We find limited SOA reductions of -2.3%, -5.6% and -4.0% for global, southeastern U.S. and Amazon NOx perturbations, respectively. To investigate the chemical processes in more detail, we also use a simplified box model with the same gas-phase chemistry and gas-aerosol partitioning mechanism as in CAM4-Chem to examine the SOA yields dependence on initial precursor emissions and background NOx level. The fact that SOA formation is almost unaffected by changes in NOx can be largely attributed to buffering in chemical pathways (low- versus high-NOx pathways, OH versus NO3-initiated oxidation) and to offsetting

  11. Uterine artery pseudoaneurysm in the setting of deep endometriosis: an uncommon cause of hemoperitoneum in pregnancy.

    PubMed

    Feld, Zoe; Rowen, Tami; Callen, Andrew; Goldstein, Ruth; Poder, Liina

    2018-02-01

    Uterine, ovarian, and placental pathologies are among the differential considerations for a pregnant woman presenting with abdominal and pelvic pain. Imaging plays a key role in the initial work-up of these patients. Sonography is often the first line test; however, evaluation of pelvic pathology can be limited in the gravid state, especially in mid- or late-term pregnancy. We present a case of a pregnant woman who came to the emergency room at 25 weeks with acute abdominal and pelvic pain. Both ultrasound and MR imaging findings revealed intraperitoneal hemorrhage, initially of unknown origin, as well as endometriomas and deep endometriosis. Only postpartum imaging confirmed a uterine artery pseudoaneurysm (PSA) presumably due to decidual reaction in deep endometriosis. We speculate the intraperitoneal hemorrhage was subsequently due to the PSA. This case demonstrates that if hemorrhage is not recognized promptly, it can lead to hemodynamic instability, as well as premature labor and delivery.

  12. Secondary eyewall formation in WRF simulations of Hurricanes Rita and Katrina (2005)

    NASA Astrophysics Data System (ADS)

    Abarca, Sergio F.; Corbosiero, Kristen L.

    2011-04-01

    An analysis is presented of two high-resolution hurricane simulations of Katrina and Rita (2005) that exhibited secondary eyewall formation (SEF). The results support the notion of vortex Rossby waves (VRWs) having an important role in SEF and suggest that VRW activity is a defining aspect of the moat. SEF occurs at a radius of ˜65 (80) km in Katrina (Rita), close to the hypothesized stagnation radius of VRWs. VRW activity appears to be the result of eye-eyewall mixing events, themselves a product of the release of barotropic instability. The convection in the radial region that becomes the moat is mainly in the form of VRWs propagating radially outward from the primary eyewall until the negative radial gradient of potential vorticity is no longer conducive for their propagation. These convectively coupled waves, originating and being expelled from the eyewall, are rotation dominated and have the coherency necessary to survive their passage through the strain-dominated region outside the eyewall.

  13. Preliminary Experience of Endovascular Embolization Using N-Butyl Cyanoacrylate for Hemoptysis due to Infectious Pulmonary Artery Pseudoaneurysms via Systemic Arterial Approach.

    PubMed

    Torikai, Hideyuki; Hasegawa, Ichiro; Jinzaki, Masahiro; Narimatsu, Yoshiaki

    2017-10-01

    We report 5 patients with hemoptysis due to infectious pulmonary artery pseudoaneurysm (PAP) treated with endovascular embolization using N-butyl cyanoacrylate (NBCA) injected via bronchial and nonbronchial systemic arterial approaches. Infectious diseases included inactive tuberculosis (n = 3), nontuberculous mycobacteriosis (n = 1), and chronic infection of unknown origin (n = 1). Seven PAPs were detected on selective systemic angiography, and injection of NBCA was performed. Disappearance of all PAPs was confirmed on systemic arteriography after the intervention. In all patients, hemoptysis was stopped without major complications, and it did not recur during the follow-up period (mean, 351 d; range, 285-427 d). Copyright © 2016 SIR. Published by Elsevier Inc. All rights reserved.

  14. Formation of Light Absorbing Soluble Secondary Organics and Insoluble Polymeric Particles from the Dark Reaction of Catechol and Guaiacol with Fe(III).

    PubMed

    Slikboer, Samantha; Grandy, Lindsay; Blair, Sandra L; Nizkorodov, Sergey A; Smith, Richard W; Al-Abadleh, Hind A

    2015-07-07

    Transition metals such as iron are reactive components of environmentally relevant surfaces. Here, dark reaction of Fe(III) with catechol and guaiacol was investigated in an aqueous solution at pH 3 under experimental conditions that mimic reactions in the adsorbed phase of water. Using UV-vis spectroscopy, liquid chromatography, mass spectrometry, elemental analysis, dynamic light scattering, and electron microscopy techniques, we characterized the reactants, intermediates, and products as a function of reaction time. The reactions of Fe(III) with catechol and guaiacol produced significant changes in the optical spectra of the solutions due to the formation of light absorbing secondary organics and colloidal organic particles. The primary steps in the reaction mechanism were shown to include oxidation of catechol and guaiacol to hydroxy- and methoxy-quinones. The particles formed within a few minutes of reaction and grew to micron-size aggregates after half an hour reaction. The mass-normalized absorption coefficients of the particles were comparable to those of strongly absorbing brown carbon compounds produced by biomass burning. These results could account for new pathways that lead to atmospheric secondary organic aerosol formation and abiotic polymer formation on environmental surfaces mediated by transition metals.

  15. Interactions between SO2 oxidation and Secondary Organic Aerosol formation through Criegee intermediate chemistry

    NASA Astrophysics Data System (ADS)

    Chan, A. W. H.; Ye, J.; Abbatt, J.

    2016-12-01

    Ozonolysis of monoterpenes is an important source of atmospheric biogenic secondary organic aerosol (BSOA). While enhanced BSOA formation has been repeatedly observed under sulfate-rich conditions in both field studies and laboratory experiments, the underlying mechanisms remain poorly understood. In this work, the effect of SO2 on BSOA formation from monoterpene ozonolysis was investigated. The role of stabilized Criegee biradicals (sCIs) generated from alkene ozonolysis on SO2 oxidation was examined under different humidity conditions (<5% vs. 50%). Experiments were conducted in a 1 m3 Teflon chamber. BSOA was produced from ozonolysis of a-pinene or limonene. SO2 concentration was injected at various levels ranging from 30 to 100 ppb. In all experiments, cyclohexane was used as OH scavenger and added at sufficient amount to minimize the influence from OH + monoterpenes reaction. SOA samples were collected for composition analysis. Preliminary results show that BSOA from monoterpene ozonolysis is significantly enhanced in the presence of SO2 under dry conditions. SOA enhancement increases with increasing the concentration of SO2. However, the enhancement became negligible as the conditions became more humid. Control experiments show that SO2 is consumed at timescales consistent with oxidation by sCIs indicating that gaseous SO2 interacts directly with reactive intermediates during monoterpene ozonolysis. Organosulfate formation is probed by electrospray ionization-ion mobility time of flight mass spectrometer (ESI-IMS/TOF). The effect of SO2 on ozonolysis mechanism and chemical composition will be discussed.

  16. Treatment of a Salmonella-induced rapidly expanding aortic pseudoaneurysm involving the visceral arteries using the Cardiatis multilayer stent.

    PubMed

    Reijnen, Michel M P J; van Sterkenburg, Steven M M

    2014-10-01

    Treatment of infection-induced aortic aneurysms is among the greatest challenges nowadays of vascular surgery because the use of prosthetic material is considered unsuitable. The Cardiatis multilayer stent (Cardiatis, Isnes, Belgium) is a flow-diverting bare stent with a proven efficacy in peripheral and visceral artery aneurysms. We present a unique case of a Salmonella serotype enteritidis-induced rapidly expanding aortic pseudoaneurysm with a penetrating ulcer that was treated with the Cardiatis multilayer stent. At 18 months of follow-up, the patient was in good clinical condition, with normalized C-reactive protein levels. Computed tomography angiography and 2-deoxy-2-[F18]-fluoro-d-glucose-positron-emission tomography/computed tomography showed a stable, mostly thrombosed aneurysm, with adequate perfusion of the side branches and no remaining signs of infection. Copyright © 2014 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

  17. Formation and aging of secondary organic aerosol from toluene: Changes in chemical composition, volatility, and hygroscopicity

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hildebrandt Ruiz, L.; Paciga, A. L.; Cerully, K. M.

    Secondary organic aerosol (SOA) is transformed after its initial formation, but this chemical aging of SOA is poorly understood. Experiments were conducted in the Carnegie Mellon environmental chamber to form secondary organic aerosol (SOA) from the photo-oxidation of toluene and other small aromatic volatile organic compounds (VOCs) in the presence of NO x under different oxidizing conditions. The effects of the oxidizing condition on organic aerosol (OA) composition, mass yield, volatility, and hygroscopicity were explored. Higher exposure to the hydroxyl radical resulted in different OA composition, average carbon oxidation state (OS c), and mass yield. The OA oxidation state generallymore » increased during photo-oxidation, and the final OA OS c ranged from –0.29 to 0.16 in the performed experiments. The volatility of OA formed in these different experiments varied by as much as a factor of 30, demonstrating that the OA formed under different oxidizing conditions can have a significantly different saturation concentration. In conclusion, there was no clear correlation between hygroscopicity and oxidation state for this relatively hygroscopic SOA.« less

  18. Formation and aging of secondary organic aerosol from toluene: Changes in chemical composition, volatility, and hygroscopicity

    DOE PAGES

    Hildebrandt Ruiz, L.; Paciga, A. L.; Cerully, K. M.; ...

    2015-07-24

    Secondary organic aerosol (SOA) is transformed after its initial formation, but this chemical aging of SOA is poorly understood. Experiments were conducted in the Carnegie Mellon environmental chamber to form secondary organic aerosol (SOA) from the photo-oxidation of toluene and other small aromatic volatile organic compounds (VOCs) in the presence of NO x under different oxidizing conditions. The effects of the oxidizing condition on organic aerosol (OA) composition, mass yield, volatility, and hygroscopicity were explored. Higher exposure to the hydroxyl radical resulted in different OA composition, average carbon oxidation state (OS c), and mass yield. The OA oxidation state generallymore » increased during photo-oxidation, and the final OA OS c ranged from –0.29 to 0.16 in the performed experiments. The volatility of OA formed in these different experiments varied by as much as a factor of 30, demonstrating that the OA formed under different oxidizing conditions can have a significantly different saturation concentration. In conclusion, there was no clear correlation between hygroscopicity and oxidation state for this relatively hygroscopic SOA.« less

  19. Secondary Organic Aerosol Formation from Glyoxal: photochemical versus dark uptake and reversible versus irreversible SOA formation

    NASA Astrophysics Data System (ADS)

    Waxman, E.; Slowik, J. G.; Kampf, C. J.; Timkovsky, J.; Noziere, B.; Praplan, A. P.; Pfaffenberger, L.; Holzinger, R.; Hoffmann, T.; Dommen, J.; Prevot, A. S.; Baltensperger, U.; Volkamer, R.

    2011-12-01

    Glyoxal forms secondary organic aerosol (SOA) by partitioning to the aerosol aqueous phase according to Henry's law. The subsequent processing by heterogeneous and multiphase reactions shifts the partitioning towards aerosols. Currently it is not well understood whether these reactions result in reversible or irreversible SOA formation, and what parameters influence the rate limiting step of multiphase processing. We conducted a series of simulation chamber experiments at PSI in April and May 2011 to investigate processing under dark conditions, UV and/or visible light irradiated conditions, and in the presence and absence of OH radicals. Experiments used ammonium sulfate or ammonium sulfate/fulvic acid mixtures as seed aerosols, and were conducted between 50% and 85% relative humidity at approximately constant RH over the course of any given experiment. Glyoxal was produced photochemically from acetylene, using HONO photolysis as the OH radical source. Gas-phase glyoxal was measured by the CU LED-Cavity Enhanced-DOAS. The Thermal-Desorption Proton-Transfer-Reaction Mass Spectrometer (TD-PTR-MS) and Ion Chromatography Mass Spectrometer (IC-MS) monitored both gas and aerosol-phase organic reaction products. Particle composition was monitored by High-Resolution Time-of-Flight Aerosol Mass Spectrometry (HR-ToF-AMS), and HPLC-ESI MS/MS and LC-MS analysis of filter samples.

  20. Secondary Organic Aerosol Formation from Glyoxal: photochemical versus dark uptake and reversible versus irreversible SOA formation

    NASA Astrophysics Data System (ADS)

    Waxman, E.; Slowik, J.; Kampf, C.; Timkovsky, J.; Noziere, B.; Praplan, A.; Pffafenberger, L.; Holzinger, R.; Hoffmann, T.; Dommen, J.; Prevot, A.; Baltensperger, U.; Volkamer, R.

    2012-04-01

    Glyoxal forms secondary organic aerosol (SOA) by partitioning to the aerosol aqueous phase according to Henry's law. The subsequent processing by heterogeneous and multiphase reactions shifts the partitioning towards aerosols. Currently it is not well understood whether these reactions result in reversible or irreversible SOA formation, and what parameters influence the rate limiting step of multiphase processing. We conducted a series of simulation chamber experiments at PSI in April and May 2011 to investigate processing under dark conditions, UV and/or visible light irradiated conditions, and in the presence and absence of OH radicals. Experiments used ammonium sulfate or ammonium sulfate/fulvic acid mixtures as seed aerosols, and were conducted between 50% and 85% relative humidity at approximately constant RH over the course of any given experiment. Glyoxal was produced photochemically from acetylene, using HONO photolysis as the OH radical source. Gas-phase glyoxal was measured by the CU LED-Cavity Enhanced-DOAS. The Thermal-Desorption Proton-Transfer-Reaction Mass Spectrometer (TD-PTR-MS) and Ion Chromatography Mass Spectrometer (IC-MS) monitored both gas and aerosol-phase organic reaction products. Particle composition was monitored by High-Resolution Time-of-Flight Aerosol Mass Spectrometry (HR-ToF-AMS), and HPLC-ESI MS/MS and LC-MS analysis of filter samples.

  1. Incremental Reactivity Effects on Secondary Organic Aerosol Formation in Urban Atmospheres with and without Biogenic Influence

    NASA Astrophysics Data System (ADS)

    Kacarab, Mary; Li, Lijie; Carter, William P. L.; Cocker, David R., III

    2016-04-01

    Two different surrogate mixtures of anthropogenic and biogenic volatile organic compounds (VOCs) were developed to study secondary organic aerosol (SOA) formation at atmospheric reactivities similar to urban regions with varying biogenic influence levels. Environmental chamber simulations were designed to enable the study of the incremental aerosol formation from select anthropogenic (m-Xylene, 1,2,4-Trimethylbenzene, and 1-Methylnaphthalene) and biogenic (α-pinene) precursors under the chemical reactivity set by the two different surrogate mixtures. The surrogate reactive organic gas (ROG) mixtures were based on that used to develop the maximum incremental reactivity (MIR) factors for evaluation of O3 forming potential. Multiple incremental aerosol formation experiments were performed in the University of California Riverside (UCR) College of Engineering Center for Environmental Research and Technology (CE-CERT) dual 90m3 environmental chambers. Incremental aerosol yields were determined for each of the VOCs studied and compared to yields found from single precursor studies. Aerosol physical properties of density, volatility, and hygroscopicity were monitored throughout experiments. Bulk elemental chemical composition from high-resolution time of flight aerosol mass spectrometer (HR-ToF-AMS) data will also be presented. Incremental yields and SOA chemical and physical characteristics will be compared with data from previous single VOC studies conducted for these aerosol precursors following traditional VOC/NOx chamber experiments. Evaluation of the incremental effects of VOCs on SOA formation and properties are paramount in evaluating how to best extrapolate environmental chamber observations to the ambient atmosphere and provides useful insights into current SOA formation models. Further, the comparison of incremental SOA from VOCs in varying surrogate urban atmospheres (with and without strong biogenic influence) allows for a unique perspective on the impacts

  2. Outcomes of Ultrasound-Guided Thrombin Injection of Nongroin Arterial Pseudoaneurysms.

    PubMed

    Valesano, Johnathan C; Schmitz, John J; Kurup, A Nicholas; Schmit, Grant D; Moynagh, Michael R; Atwell, Thomas D; Lewis, Bradley D; Lee, Robert A; Callstrom, Matthew R

    2017-08-01

    To evaluate success and complication rates of percutaneous ultrasound-guided thrombin injection of nongroin pseudoaneurysms (PSAs). Retrospective review of a prospectively maintained institutional database yielded 39 cases of arterial PSAs occurring at nongroin sites that were treated with percutaneous ultrasound-guided thrombin injection between 2000 and 2016 (average patient age 69.2 y ± 14.0). Of PSAs, 74.4% (29/39) arose in the upper extremities, and 92.3% (36/39) were iatrogenic. The brachial artery was the most commonly affected vessel (51.3% [20/39]), and arterial access was the most common cause (56.4% [22/39]). Average overall PSA size was 2.4 cm (range, 0.5-7.2 cm); average amount of thrombin injected was 320 IU (range, 50-2,000 IU). Technical success was defined as absence of flow within the PSA immediately after thrombin injection. Treatment success was defined as sustained thrombosis on follow-up imaging obtained at 1-3 days after treatment. Technical and treatment success rates of thrombin injections were 100% (39/39) and 84.8% (28/33), respectively. Longer term follow-up imaging (average 71 d; range, 12-201 d) was available for 7 of the treatment successes with 100% (7/7) showing sustained thrombosis. Comparing treatment successes and failures, there was no significant difference in average PSA size (2.3 cm vs 2.0 cm, P = .51) or average amount of thrombin injected (360 IU vs 180 IU, P = .14). There were no complications. Ultrasound-guided thrombin injection is a safe, efficacious treatment option for PSAs arising in nongroin locations. Copyright © 2017 SIR. Published by Elsevier Inc. All rights reserved.

  3. Influence of ultrasound enhancement on chlorine dioxide consumption and disinfection by-products formation for secondary effluents disinfection.

    PubMed

    Zhou, Xiaoqin; Zhao, Junyuan; Li, Zifu; Lan, Juanru; Li, Yajie; Yang, Xin; Wang, Dongling

    2016-01-01

    Chlorine dioxide (ClO2) has been promoted as an alternative disinfectant because of its high disinfection efficiency and less formation of organic disinfection by-products (DBPs). However, particle-associated microorganisms could be protected during the disinfection process, which decreases the disinfection efficiency or increases the required dosage. Besides, the formation of inorganic disinfection by-products is a significant concern in environment health. Ultrasound (US)-combined disinfection methods are becoming increasingly attractive because they are efficient and environmentally friendly. In this study, US was introduced as an enhancement method to identify its influence on ClO2 demand reduction and to minimize the production of potential DBPs for secondary effluents disinfection. Fecal coliform was used as an indicator, and DBPs, including trichloromethane (TCM), dichloroacetic acid (DCAA), trichloroacetic acid (TCAA), chlorite (ClO2(-)), and chlorate (ClO3(-)), were analyzed to observe the potential DBPs formation. Results show that US pretreatment could reduce half of ClO2 dosage compared with ClO2 disinfection alone for the same disinfection efficiency, and that an input power density of 2.64 kJ/L pretreatment with the 1.5mg/L ClO2 was enough to meet the discharge requirement in China (i.e., fecal coliform below 1000 CFU/L for Class 1A) for secondary effluent disinfection, and the ClO2(-) concentration in the disinfection effluent was only 1.37 mg/L at the same time. Furthermore, the different effects of US on the two processes (US as pretreatment and simultaneous US/ClO2 disinfection) were also analyzed, including deagglomerating, cell damage, and synergistic disinfection as well as degasing/sonolysis. It was proved that the production of TCM, DCAA, and TCAA was insignificantly influenced with the introduction of US, but US pretreatment did reduce the production of ClO2(-) and ClO3(-) effectually. In general, US pretreatment could be a better option for

  4. Limited effect of anthropogenic nitrogen oxides on secondary organic aerosol formation

    NASA Astrophysics Data System (ADS)

    Zheng, Y.; Unger, N.; Hodzic, A.; Emmons, L.; Knote, C.; Tilmes, S.; Lamarque, J.-F.; Yu, P.

    2015-12-01

    Globally, secondary organic aerosol (SOA) is mostly formed from emissions of biogenic volatile organic compounds (VOCs) by vegetation, but it can be modified by human activities as demonstrated in recent research. Specifically, nitrogen oxides (NOx = NO + NO2) have been shown to play a critical role in the chemical formation of low volatility compounds. We have updated the SOA scheme in the global NCAR (National Center for Atmospheric Research) Community Atmospheric Model version 4 with chemistry (CAM4-chem) by implementing a 4-product volatility basis set (VBS) scheme, including NOx-dependent SOA yields and aging parameterizations. Small differences are found for the no-aging VBS and 2-product schemes; large increases in SOA production and the SOA-to-OA ratio are found for the aging scheme. The predicted organic aerosol amounts capture both the magnitude and distribution of US surface annual mean measurements from the Interagency Monitoring of Protected Visual Environments (IMPROVE) network by 50 %, and the simulated vertical profiles are within a factor of 2 compared to aerosol mass spectrometer (AMS) measurements from 13 aircraft-based field campaigns across different regions and seasons. We then perform sensitivity experiments to examine how the SOA loading responds to a 50 % reduction in anthropogenic nitric oxide (NO) emissions in different regions. We find limited SOA reductions of 0.9-5.6, 6.4-12.0 and 0.9-2.8 % for global, southeast US and Amazon NOx perturbations, respectively. The fact that SOA formation is almost unaffected by changes in NOx can be largely attributed to a limited shift in chemical regime, to buffering in chemical pathways (low- and high-NOx pathways, O3 versus NO3-initiated oxidation) and to offsetting tendencies in the biogenic versus anthropogenic SOA responses.

  5. Limited effect of anthropogenic nitrogen oxides on secondary organic aerosol formation

    DOE PAGES

    Zheng, Y.; Unger, N.; Hodzic, A.; ...

    2015-12-08

    Globally, secondary organic aerosol (SOA) is mostly formed from emissions of biogenic volatile organic compounds (VOCs) by vegetation, but it can be modified by human activities as demonstrated in recent research. Specifically, nitrogen oxides (NO x = NO + NO 2) have been shown to play a critical role in the chemical formation of low volatility compounds. We have updated the SOA scheme in the global NCAR (National Center for Atmospheric Research) Community Atmospheric Model version 4 with chemistry (CAM4-chem) by implementing a 4-product volatility basis set (VBS) scheme, including NO x-dependent SOA yields and aging parameterizations. Small differences aremore » found for the no-aging VBS and 2-product schemes; large increases in SOA production and the SOA-to-OA ratio are found for the aging scheme. The predicted organic aerosol amounts capture both the magnitude and distribution of US surface annual mean measurements from the Interagency Monitoring of Protected Visual Environments (IMPROVE) network by 50 %, and the simulated vertical profiles are within a factor of 2 compared to aerosol mass spectrometer (AMS) measurements from 13 aircraft-based field campaigns across different regions and seasons. We then perform sensitivity experiments to examine how the SOA loading responds to a 50 % reduction in anthropogenic nitric oxide (NO) emissions in different regions. We find limited SOA reductions of 0.9–5.6, 6.4–12.0 and 0.9–2.8 % for global, southeast US and Amazon NO x perturbations, respectively. The fact that SOA formation is almost unaffected by changes in NO x can be largely attributed to a limited shift in chemical regime, to buffering in chemical pathways (low- and high-NO x pathways, O 3 versus NO 3-initiated oxidation) and to offsetting tendencies in the biogenic versus anthropogenic SOA responses.« less

  6. The force-sensing peptide VemP employs extreme compaction and secondary structure formation to induce ribosomal stalling.

    PubMed

    Su, Ting; Cheng, Jingdong; Sohmen, Daniel; Hedman, Rickard; Berninghausen, Otto; von Heijne, Gunnar; Wilson, Daniel N; Beckmann, Roland

    2017-05-30

    Interaction between the nascent polypeptide chain and the ribosomal exit tunnel can modulate the rate of translation and induce translational arrest to regulate expression of downstream genes. The ribosomal tunnel also provides a protected environment for initial protein folding events. Here, we present a 2.9 Å cryo-electron microscopy structure of a ribosome stalled during translation of the extremely compacted VemP nascent chain. The nascent chain forms two α-helices connected by an α-turn and a loop, enabling a total of 37 amino acids to be observed within the first 50-55 Å of the exit tunnel. The structure reveals how α-helix formation directly within the peptidyltransferase center of the ribosome interferes with aminoacyl-tRNA accommodation, suggesting that during canonical translation, a major role of the exit tunnel is to prevent excessive secondary structure formation that can interfere with the peptidyltransferase activity of the ribosome.

  7. Sequential Metabolism of Secondary Alkyl Amines to Metabolic-Intermediate Complexes: Opposing Roles for the Secondary Hydroxylamine and Primary Amine Metabolites of Desipramine, (S)-Fluoxetine, and N-Desmethyldiltiazem

    PubMed Central

    Hanson, Kelsey L.; VandenBrink, Brooke M.; Babu, Kantipudi N.; Allen, Kyle E.; Nelson, Wendel L.

    2010-01-01

    Three secondary amines desipramine (DES), (S)-fluoxetine [(S)-FLX], and N-desmethyldiltiazem (MA) undergo N-hydroxylation to the corresponding secondary hydroxylamines [N-hydroxydesipramine, (S)-N-hydroxyfluoxetine, and N-hydroxy-N-desmethyldiltiazem] by cytochromes P450 2C11, 2C19, and 3A4, respectively. The expected primary amine products, N-desmethyldesipramine, (S)-norfluoxetine, and N,N-didesmethyldiltiazem, are also observed. The formation of metabolic-intermediate (MI) complexes from these substrates and metabolites was examined. In each example, the initial rates of MI complex accumulation followed the order secondary hydroxylamine > secondary amine ≫ primary amine, suggesting that the primary amine metabolites do not contribute to formation of MI complexes from these secondary amines. Furthermore, the primary amine metabolites, which accumulate in incubations of the secondary amines, inhibit MI complex formation. Mass balance studies provided estimates of the product ratios of N-dealkylation to N-hydroxylation. The ratios were 2.9 (DES-CYP2C11), 3.6 [(S)-FLX-CYP2C19], and 0.8 (MA-CYP3A4), indicating that secondary hydroxylamines are significant metabolites of the P450-mediated metabolism of secondary alkyl amines. Parallel studies with N-methyl-d3-desipramine and CYP2C11 demonstrated significant isotopically sensitive switching from N-demethylation to N-hydroxylation. These findings demonstrate that the major pathway to MI complex formation from these secondary amines arises from N-hydroxylation rather than N-dealkylation and that the primary amines are significant competitive inhibitors of MI complex formation. PMID:20200233

  8. Sequential metabolism of secondary alkyl amines to metabolic-intermediate complexes: opposing roles for the secondary hydroxylamine and primary amine metabolites of desipramine, (s)-fluoxetine, and N-desmethyldiltiazem.

    PubMed

    Hanson, Kelsey L; VandenBrink, Brooke M; Babu, Kantipudi N; Allen, Kyle E; Nelson, Wendel L; Kunze, Kent L

    2010-06-01

    Three secondary amines desipramine (DES), (S)-fluoxetine [(S)-FLX], and N-desmethyldiltiazem (MA) undergo N-hydroxylation to the corresponding secondary hydroxylamines [N-hydroxydesipramine, (S)-N-hydroxyfluoxetine, and N-hydroxy-N-desmethyldiltiazem] by cytochromes P450 2C11, 2C19, and 3A4, respectively. The expected primary amine products, N-desmethyldesipramine, (S)-norfluoxetine, and N,N-didesmethyldiltiazem, are also observed. The formation of metabolic-intermediate (MI) complexes from these substrates and metabolites was examined. In each example, the initial rates of MI complex accumulation followed the order secondary hydroxylamine > secondary amine > primary amine, suggesting that the primary amine metabolites do not contribute to formation of MI complexes from these secondary amines. Furthermore, the primary amine metabolites, which accumulate in incubations of the secondary amines, inhibit MI complex formation. Mass balance studies provided estimates of the product ratios of N-dealkylation to N-hydroxylation. The ratios were 2.9 (DES-CYP2C11), 3.6 [(S)-FLX-CYP2C19], and 0.8 (MA-CYP3A4), indicating that secondary hydroxylamines are significant metabolites of the P450-mediated metabolism of secondary alkyl amines. Parallel studies with N-methyl-d(3)-desipramine and CYP2C11 demonstrated significant isotopically sensitive switching from N-demethylation to N-hydroxylation. These findings demonstrate that the major pathway to MI complex formation from these secondary amines arises from N-hydroxylation rather than N-dealkylation and that the primary amines are significant competitive inhibitors of MI complex formation.

  9. The Dual Functions of WLIM1a in Cell Elongation and Secondary Wall Formation in Developing Cotton Fibers[C][W

    PubMed Central

    Han, Li-Bo; Li, Yuan-Bao; Wang, Hai-Yun; Wu, Xiao-Min; Li, Chun-Li; Luo, Ming; Wu, Shen-Jie; Kong, Zhao-Sheng; Pei, Yan; Jiao, Gai-Li; Xia, Gui-Xian

    2013-01-01

    LIN-11, Isl1 and MEC-3 (LIM)-domain proteins play pivotal roles in a variety of cellular processes in animals, but plant LIM functions remain largely unexplored. Here, we demonstrate dual roles of the WLIM1a gene in fiber development in upland cotton (Gossypium hirsutum). WLIM1a is preferentially expressed during the elongation and secondary wall synthesis stages in developing fibers. Overexpression of WLIM1a in cotton led to significant changes in fiber length and secondary wall structure. Compared with the wild type, fibers of WLIM1a-overexpressing plants grew longer and formed a thinner and more compact secondary cell wall, which contributed to improved fiber strength and fineness. Functional studies demonstrated that (1) WLIM1a acts as an actin bundler to facilitate elongation of fiber cells and (2) WLIM1a also functions as a transcription factor to activate expression of Phe ammonia lyase–box genes involved in phenylpropanoid biosynthesis to build up the secondary cell wall. WLIM1a localizes in the cytosol and nucleus and moves into the nucleus in response to hydrogen peroxide. Taken together, these results demonstrate that WLIM1a has dual roles in cotton fiber development, elongation, and secondary wall formation. Moreover, our study shows that lignin/lignin-like phenolics may substantially affect cotton fiber quality; this finding may guide cotton breeding for improved fiber traits. PMID:24220634

  10. Interpretation of Secondary Organic Aerosol Formation from Diesel Exhaust Photooxidation in an Environmental Chamber

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Nakao, Shunsuke; Shrivastava, ManishKumar B.; Nguyen, Anh

    2011-04-14

    Secondary organic aerosol (SOA) formation from diesel exhaust in a smog chamber was investigated. Particle volume measurement based on mobility diameter is shown to underestimate SOA formation from diesel exhaust due to the external void space of agglomerate particles, in which case mass-based measurement technique is necessary. Rapid determination of particle effective density as a function of particle mass was performed by an Aerosol Particle Mass analyzer – Scanning Mobility Particle Sizer (APM-SMPS) to obtain particle mass concentration and fractal dimension. Continuous aging of aerosol was observed in terms of atomic ratio (O/C), from 0.05 to 0.25 in 12 hours,more » underscoring the importance of multi-generational oxidation of low-volatile organic vapors emitted from diesel engine as the significant source of oxygenated SOA. Experimental conditions possibly have strong impacts on physical evolution of diesel particulates in a smog chamber. Higher particle effective densities were observed when raw exhaust was injected into a full bag as opposed to filling a bag with diluted exhaust using an ejector diluter. When longer transfer line was used for injecting diesel exhaust into the smog chamber, rapid particle coagulation was observed, leading to increasing particle volume concentration in dark while its mass concentration is decreasing.« less

  11. Review of Urban Secondary Organic Aerosol Formation from Gasoline and Diesel Motor Vehicle Emissions.

    PubMed

    Gentner, Drew R; Jathar, Shantanu H; Gordon, Timothy D; Bahreini, Roya; Day, Douglas A; El Haddad, Imad; Hayes, Patrick L; Pieber, Simone M; Platt, Stephen M; de Gouw, Joost; Goldstein, Allen H; Harley, Robert A; Jimenez, Jose L; Prévôt, André S H; Robinson, Allen L

    2017-02-07

    Secondary organic aerosol (SOA) is formed from the atmospheric oxidation of gas-phase organic compounds leading to the formation of particle mass. Gasoline- and diesel-powered motor vehicles, both on/off-road, are important sources of SOA precursors. They emit complex mixtures of gas-phase organic compounds that vary in volatility and molecular structure-factors that influence their contributions to urban SOA. However, the relative importance of each vehicle type with respect to SOA formation remains unclear due to conflicting evidence from recent laboratory, field, and modeling studies. Both are likely important, with evolving contributions that vary with location and over short time scales. This review summarizes evidence, research needs, and discrepancies between top-down and bottom-up approaches used to estimate SOA from motor vehicles, focusing on inconsistencies between molecular-level understanding and regional observations. The effect of emission controls (e.g., exhaust aftertreatment technologies, fuel formulation) on SOA precursor emissions needs comprehensive evaluation, especially with international perspective given heterogeneity in regulations and technology penetration. Novel studies are needed to identify and quantify "missing" emissions that appear to contribute substantially to SOA production, especially in gasoline vehicles with the most advanced aftertreatment. Initial evidence suggests catalyzed diesel particulate filters greatly reduce emissions of SOA precursors along with primary aerosol.

  12. Abnormal electron-heating mode and formation of secondary-energetic electrons in pulsed microwave-frequency atmospheric microplasmas

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kwon, H. C.; Research and Development Division, SK Hynix Semiconductor Inc., Icheon 467-701; Jung, S. Y.

    2014-03-15

    The formation of secondary energetic electrons induced by an abnormal electron-heating mode in pulsed microwave-frequency atmospheric microplasmas was investigated using particle-in-cell simulation. We found that additional high electron heating only occurs during the first period of the ignition phase after the start of a second pulse at sub-millimeter dimensions. During this period, the electrons are unable to follow the abruptly retreating sheath through diffusion alone. Thus, a self-consistent electric field is induced to drive the electrons toward the electrode. These behaviors result in an abnormal electron-heating mode that produces high-energy electrons at the electrode with energies greater than 50 eV.

  13. Development and Application of an Oxidation Flow Reactor to Study Secondary Organic Aerosol Formation from Ambient Air

    NASA Astrophysics Data System (ADS)

    Palm, Brett Brian

    Secondary organic aerosols (SOA) in the atmosphere play an important role in air quality, human health, and climate. However, the sources, formation pathways, and fate of SOA are poorly constrained. In this dissertation, I present development and application of the oxidation flow reactor (OFR) technique for studying SOA formation from OH, O3, and NO3 oxidation of ambient air. With a several-minute residence time and a portable design with no inlet, OFRs are particularly well-suited for this purpose. I first introduce the OFR concept, and discuss several advances I have made in performing and interpreting OFR experiments. This includes estimating oxidant exposures, modeling the fate of low-volatility gases in the OFR (wall loss, condensation, and oxidation), and comparing SOA yields of single precursors in the OFR with yields measured in environmental chambers. When these experimental details are carefully considered, SOA formation in an OFR can be more reliably compared with ambient SOA formation processes. I then present an overview of what OFR measurements have taught us about SOA formation in the atmosphere. I provide a comparison of SOA formation from OH, O3, and NO3 oxidation of ambient air in a wide variety of environments, from rural forests to urban air. In a rural forest, the SOA formation correlated with biogenic precursors (e.g., monoterpenes). In urban air, it correlated instead with reactive anthropogenic tracers (e.g., trimethylbenzene). In mixed-source regions, the SOA formation did not correlate well with any single precursor, but could be predicted by multilinear regression from several precursors. Despite these correlations, the concentrations of speciated ambient VOCs could only explain approximately 10-50% of the total SOA formed from OH oxidation. In contrast, ambient VOCs could explain all of the SOA formation observed from O3 and NO3 oxidation. Evidence suggests that lower-volatility gases (semivolatile and intermediate-volatility organic

  14. Impact of chamber wall loss of gaseous organic compounds on secondary organic aerosol formation: Explicit modeling of SOA formation from alkane and alkene oxidation

    DOE PAGES

    La, Y. S.; Camredon, M.; Ziemann, P. J.; ...

    2016-02-08

    Recent studies have shown that low volatility gas-phase species can be lost onto the smog chamber wall surfaces. Although this loss of organic vapors to walls could be substantial during experiments, its effect on secondary organic aerosol (SOA) formation has not been well characterized and quantified yet. Here the potential impact of chamber walls on the loss of gaseous organic species and SOA formation has been explored using the Generator for Explicit Chemistry and Kinetics of the Organics in the Atmosphere (GECKO-A) modeling tool, which explicitly represents SOA formation and gas–wall partitioning. The model was compared with 41 smog chambermore » experiments of SOA formation under OH oxidation of alkane and alkene series (linear, cyclic and C 12-branched alkanes and terminal, internal and 2-methyl alkenes with 7 to 17 carbon atoms) under high NO x conditions. Simulated trends match observed trends within and between homologous series. The loss of organic vapors to the chamber walls is found to affect SOA yields as well as the composition of the gas and the particle phases. Simulated distributions of the species in various phases suggest that nitrates, hydroxynitrates and carbonylesters could substantially be lost onto walls. The extent of this process depends on the rate of gas–wall mass transfer, the vapor pressure of the species and the duration of the experiments. Furthermore, this work suggests that SOA yields inferred from chamber experiments could be underestimated up a factor of 2 due to the loss of organic vapors to chamber walls.« less

  15. Secondary organic aerosol and ozone formation from photo-oxidation of unburned diesel fuel in a surrogate atmospheric environment

    NASA Astrophysics Data System (ADS)

    Li, Weihua; Cocker, David R.

    2018-07-01

    Diesel fuel is a complex mixture of intermediate volatility organic compounds (IVOCs). Previous studies focused on secondary organic aerosol (SOA) and ozone formation from photo-oxidation of organic vapor from diesel exhaust and their components such as aromatics and heavy alkanes. However, there are few studies on atmospheric behavior of unburnt diesel. Therefore, in this study, ten unburnt #2 commercial diesel samples and one FACE9A research diesel fuel were photo-oxidized in the University of California Riverside, College of Engineering-Center for Environmental Research & Technology dual environmental chambers to investigate their SOA and ozone production potential. Photochemical aging rapidly produced significant SOA (yield ∼20.3-37.7%) in the presence of a surrogate reactive organic gas (ROG) mixture used to mimic urban atmospheric reactivity. SOA yields were consistent with n-Heptadecane yields under similar conditions. Doubling NOx concentrations within relevant urban concentration levels enhanced SOA formation by 33% and ozone formation by 48%. SOA formation in this study was approximately fourteen times higher than previously reported for very high NOx conditions. An SOA experiment designed to mimic the previous work achieved similar yields to the earlier work. SOA formed under urban relevant NOx concentrations were consistent with semi-volatile-oxygenated organic aerosol (SV-OOA) and underwent little further chemical processing once produced.

  16. The force-sensing peptide VemP employs extreme compaction and secondary structure formation to induce ribosomal stalling

    PubMed Central

    Su, Ting; Cheng, Jingdong; Sohmen, Daniel; Hedman, Rickard; Berninghausen, Otto; von Heijne, Gunnar; Wilson, Daniel N; Beckmann, Roland

    2017-01-01

    Interaction between the nascent polypeptide chain and the ribosomal exit tunnel can modulate the rate of translation and induce translational arrest to regulate expression of downstream genes. The ribosomal tunnel also provides a protected environment for initial protein folding events. Here, we present a 2.9 Å cryo-electron microscopy structure of a ribosome stalled during translation of the extremely compacted VemP nascent chain. The nascent chain forms two α-helices connected by an α-turn and a loop, enabling a total of 37 amino acids to be observed within the first 50–55 Å of the exit tunnel. The structure reveals how α-helix formation directly within the peptidyltransferase center of the ribosome interferes with aminoacyl-tRNA accommodation, suggesting that during canonical translation, a major role of the exit tunnel is to prevent excessive secondary structure formation that can interfere with the peptidyltransferase activity of the ribosome. DOI: http://dx.doi.org/10.7554/eLife.25642.001 PMID:28556777

  17. Gas-phase products and secondary organic aerosol formation from the ozonolysis and photooxidation of myrcene

    NASA Astrophysics Data System (ADS)

    Böge, Olaf; Mutzel, Anke; Iinuma, Yoshiteru; Yli-Pirilä, Pasi; Kahnt, Ariane; Joutsensaari, Jorma; Herrmann, Hartmut

    2013-11-01

    In this study, the ozone and OH-radical reactions of myrcene were investigated in an aerosol chamber (at 292-295 K and 50% relative humidity) to examine the gas-phase oxidation products and secondary organic aerosol (SOA) formation. The ozone reaction studies were performed in the presence and absence of CO, which serves as an OH radical scavenger. In the photooxidation experiments OH radicals were generated by photolysis of methyl nitrite. The ozonolysis of myrcene in the presence of CO resulted in a substantial yield of 4-vinyl-4-pentenal (55.3%), measured as m/z 111 plus m/z 93 using proton transfer reaction-mass spectrometry (PTR-MS) and confirmed unambiguously as C7H10O by denuder measurements and HPLC/ESI-TOFMS analysis of its 2,4-dinitrophenylhydrazine (DNPH) derivative. Additionally, the formation of two different organic dicarbonyls with m/z 113 and a molecular formula of C6H8O2 were observed (2.1%). The yields of these dicarbonyls were higher in the ozonolysis experiments without an OH scavenger (5.4%) and even higher (13.8%) in the myrcene OH radical reaction. The formation of hydroxyacetone as a direct product of the myrcene reaction with ozone with a molar yield of 17.6% was also observed. The particle size distribution and volume concentrations were monitored and facilitated the calculation of SOA yields, which ranged from 0 to 0.01 (ozonolysis in the presence of CO) to 0.39 (myrcene OH radical reaction). Terpenylic acid was found in the SOA samples collected from the ozonolysis of myrcene in the absence of an OH scavenger and the OH radical-initiated reaction of myrcene but not in samples collected from the ozonolysis in the presence of CO as an OH radical scavenger, suggesting that terpenylic acid formation involves the reaction of myrcene with an OH radical. A reaction mechanism describing the formation of terpenylic acid is proposed.

  18. Percutaneous Treatment of Iatrogenic Pseudoaneurysms by Cyanoacrylate-Based Wall-Gluing

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Del Corso, Andrea, E-mail: adelcorso2000@hotmail.com; Vergaro, Giuseppe

    Purpose. Although the majority of iatrogenic pseudoaneurysms (PSAs) are amenable to ultrasound (US)-guided thrombin injection, patients with those causing neuropathy, claudication, significant venous compression, or soft tissue necrosis are considered poor candidates for this option and referred to surgery. We aimed to test the effectiveness and feasibility of a novel percutaneous cyanoacrylate glue (NBCA-MS)-based technique for treatment of symptomatic and asymptomatic iatrogenic PSA. Material and Methods. During a 3-year period, we prospectively enrolled 91 patients with iatrogenic PSA [total n = 94 (femoral n = 76; brachial n = 11; radial n = 6; axillary n = 1)]. PSA weremore » asymptomatic in 66 % of cases, and 34 % presented with symptoms due to neuropathy, venous compression, and/or soft tissue necrosis. All patients signed informed consent. All patients received NBCA-MS-based percutaneous treatment. PSA chamber emptying was first obtained by US-guided compression; superior and inferior walls of the PSA chamber were then stuck together using NBCA-MS microinjections. Successfulness of the procedure was assessed immediately and at 1-day and 1-, 3-, and 12-month US follow-up. Results. PSA occlusion rate was 99 % (93 of 94 cases). After treatment, mean PSA antero-posterior diameter decrease was 67 {+-} 22 %. Neuropathy and vein compression immediately disappeared in 91 % (29 of 32) of cases. Patients with tissue necrosis (n = 6) underwent subsequent outpatient necrosectomy. No distal embolization occurred, nor was conversion to surgery necessary. Conclusion. PSA treatment by way of NBCA-MS glue injection proved to be safe and effective in asymptomatic patients as well as those with neuropathy, venous compression, or soft-tissue necrosis (currently candidates for surgery). Larger series are needed to confirm these findings.« less

  19. Free energy determinants of secondary structure formation: III. beta-turns and their role in protein folding.

    PubMed

    Yang, A S; Hitz, B; Honig, B

    1996-06-21

    The stability of beta-turns is calculated as a function of sequence and turn type with a Monte Carlo sampling technique. The conformational energy of four internal hydrogen-bonded turn types, I, I', II and II', is obtained by evaluating their gas phase energy with the CHARMM force field and accounting for solvation effects with the Finite Difference Poisson-Boltzmann (FDPB) method. All four turn types are found to be less stable than the coil state, independent of the sequence in the turn. The free-energy penalties associated with turn formation vary between 1.6 kcal/mol and 7.7 kcal/mol, depending on the sequence and turn type. Differences in turn stability arise mainly from intraresidue interactions within the two central residues of the turn. For each combination of the two central residues, except for -Gly-Gly-, the most stable beta-turn type is always found to occur most commonly in native proteins. The fact that a model based on local interactions accounts for the observed preference of specific sequences suggests that long-range tertiary interactions tend to play a secondary role in determining turn conformation. In contrast, for beta-hairpins, long-range interactions appear to dominate. Specifically, due to the right-handed twist of beta-strands, type I' turns for -Gly-Gly- are found to occur with high frequency, even when local energetics would dictate otherwise. The fact that any combination of two residues is found able to adopt a relatively low-energy turn structure explains why the amino acid sequence in turns is highly variable. The calculated free-energy cost of turn formation, when combined with related numbers obtained for alpha-helices and beta-sheets, suggests a model for the initiation of protein folding based on metastable fragments of secondary structure.

  20. Biogenic-Anthropogenic Interactions in Secondary Organic Aerosol Formation and Health Effects of Atmospheric Organic Aerosol

    NASA Astrophysics Data System (ADS)

    Ye, Jianhuai

    Secondary organic aerosol (SOA) formed from oxidation of volatile organic compounds (VOCs), comprises a major fraction of atmospheric submicron particulate matter, which is crucial for global climate change and human health. While biogenic VOCs are naturally emitted and cannot be directly controlled, field measurements and satellite observations have shown that biogenic SOA (BSOA) formation correlates well with anthropogenic pollutants and may be anthropogenically controlled. In this work, the formation of the "anthropogenically controllable BSOA" was examined. BSOA from alpha-pinene ozonolysis was investigated in the presence of laboratory-generated or ambient organic aerosol such as Toronto ambient particles. It is shown that SOA was not equally miscible with all organic species. Aerosol mixing thermodynamics in the atmosphere is composition dependent. Based on laboratory observations, an empirical framework using bulk elemental ratios was developed to predict atmospheric organic miscibility and SOA yield enhancements. Besides organic aerosol, interactions between BSOA formation and SO2 was also examined. Synergistic effects were observed between BSOA formation and SO2 oxidation through Criegee and peroxide chemistry under atmospherically relevant RH conditions. In addition to the physicochemical properties of SOA, health impacts of SOA were examined. An atmospheric simulation reactor (ASR) was developed to investigate the health effects of air pollutants by permitting controlled chronic in vivo exposure of mice to combine particulate and gaseous pollutants at 'real-life' concentrations. Results show that daily exposure to SOA from naphthalene photooxidation led to increased airway hyperresponsiveness (AHR) to methacholine in a dose-dependent manner. Multi-pollutant exposures with ozone and/or NO2 in conjunction with a sub-toxic concentration of SOA resulted in additive effects on AHR to methacholine. Inflammatory cell recruitment to the airways was not observed

  1. Campholenic aldehyde ozonolysis: a possible mechanism for the formation of specific biogenic secondary organic aerosol constituents

    NASA Astrophysics Data System (ADS)

    Kahnt, A.; Iinuma, Y.; Mutzel, A.; Böge, O.; Claeys, M.; Herrmann, H.

    2013-08-01

    In the present study, campholenic aldehyde ozonolysis was performed to investigate pathways leading to specific biogenic secondary organic aerosol (SOA) marker compounds. Campholenic aldehyde, a known α-pinene oxidation product, is suggested to be a key intermediate in the formation of terpenylic acid upon α-pinene ozonolysis. It was reacted with ozone in the presence and absence of an OH radical scavenger leading to SOA formation with a yield of 0.75 and 0.8, respectively. The resulting oxidation products in the gas and particle phases were investigated employing a denuder/filter sampling combination. Gas-phase oxidation products bearing a carbonyl group, which were collected by the denuder, were derivatised with 2,4-dinitrophenylhydrazine (DNPH) followed by Liquid Chromatography/negative ion Electrospray Ionisation Time-of-Flight Mass Spectrometry analysis and were compared to the gas-phase compounds detected by online Proton-Transfer-Reaction Mass Spectrometry. Particle-phase products were also analysed, directly or after DNPH derivatisation, to derive information about specific compounds leading to SOA formation. Among the detected compounds, the aldehydic precursor of terpenylic acid was identified and its presence was confirmed in ambient aerosol samples from the DNPH derivatisation, accurate mass data, and MS2 and MS3 fragmentation studies. Furthermore, the present investigation sheds light on a reaction pathway leading to the formation of terpenylic acid, involving α-pinene, α-pinene oxide, campholenic aldehyde, and terpenylic aldehyde. Additionally, the formation of diaterpenylic acid acetate could be connected to campholenic aldehyde oxidation. The present study also provides insights into the source of other highly functionalised oxidation products (e.g. m/z 201, C9H14O5 and m/z 215, C10H16O5), which have been observed in ambient aerosol samples and smog chamber-generated monoterpene SOA. The m/z 201 and 215 compounds were tentatively identified as a

  2. Influences of different PBL schemes on secondary eyewall formation and eyewall replacement cycle in simulated Typhoon Sinlaku (2008)

    NASA Astrophysics Data System (ADS)

    Zhang, Yutao; Jiang, Yuxin; Tan, Benkui

    2013-06-01

    The effects of different planetary boundary layer (PBL) processes on the secondary eyewall formation (SEF) and eyewall replacement cycle (ERC) in Typhoon Sinlaku (2008) are investigated by using the Weather Research and Forecasting (WRF) model with six different PBL schemes. The SEF and ERC have been successfully simulated with all the six PBL schemes and the mechanism for the SEF and ERC proposed in our previous study has been reconfirmed. It is demonstrated that both the intensification of the storm and the inward-moving outer spiral rainband contribute to the SEF. After the SEF, the associated diabatic heating enhances the secondary eyewall further, and the transfer of moist air from outer region to the primary eyewall is cut off by the secondary eyewall. In such a way, the primary eyewall dies and an ERC completes. It is found that some simulated features of the SEF and ERC, such as the time and location of the SEF and duration of the ERC, do vary from one simulation to another. In order to describe the features of the SEF and ERC quantitatively, a concentric eyewall index (CEI) is defined and a threshold of the CEI is suggested to determine the onset of the secondary eyewall. The differences in the simulated SEF and ERC are discussed and some possible causes are suggested. In addition, based on the CEI threshold and the conservation law of angular momentum, a formula to predict the location of SEF is also proposed and applied to all the six simulations. The success and failure of the formula are then discussed.

  3. Oligomerization reactions for precursors to secondary organic aerosol: Comparison between two formation mechanisms for the oligomeric hydroxyalkyl hydroperoxides

    NASA Astrophysics Data System (ADS)

    Zhao, Qiangli; Wang, Weina; Liu, Fengyi; Lü, Jian; Wang, Wenliang

    2017-10-01

    To better understand the formation mechanism of oligomeric hydroxyalkyl hydroperoxides HOROO(SCI)nH composed of stabilized Criegee intermediate (SCI) as a chain unit, the reactions of SCI with hydroxyalkyl hydroperoxides (HOROOH) and hydroxyalkylperoxy radical (HORO2) as well as HO2 radical were investigated. For the reactions of HORO2 + SCI, two preferred pathways involving a SCI insertion in HOROOH hydroperoxide bond can be found, and the formation of HOROO(SCI)H is the dominant pathway in the reaction of HOCH2(CH3)2COOH + (CH3)2COO. The structures of the HORO2, HOROOH as well as the SCIs play a crucial role in determining the reactivity of the oligomerization. Both the reactions of HORO2 + SCI + HO2 and HOROOH + SCI could be the source of the processors to the formation of secondary organic aerosol (SOA). But from the point of free energy barriers, the formation of HOROO(SCI)H prefers to follow the mechanism involving initiation by the reaction of a HORO2 and a SCI, sequential addition of SCIs, and termination by reaction with the HO2 radical. The rate coefficients show negative temperature dependence and vary in different systems depending on the reactants. The reaction process and constituents of the products can be regulated by temperature and reactants.

  4. Secondary organic aerosol formation from propylene irradiations in a chamber study

    NASA Astrophysics Data System (ADS)

    Ge, Shuangshuang; Xu, Yongfu; Jia, Long

    2017-05-01

    Some studies have shown that low-molecular-weight VOCs such as ethylene and acetylene can form SOA. However, so far propylene (C3H6) has not been studied. The current work systematically investigates irradiations of propylene in the presence of NOx (x = 1, 2) in a self-made indoor chamber. Only a small amount of secondary organic aerosols (SOA) was formed under 5% and 80% RH conditions without sodium chloride (NaCl) seed particles or in the presence of solid NaCl. When NaCl was in the form of droplets, liquid water content (LWC) increased from 34.5 to 169.8 μg m-3 under different initial NaCl concentrations, and correspondingly the amount of SOA linearly increased from 5.9 to 29.8 μg m-3 (SOA = 0.0164 × LWC+1.137, R2 = 0.97) at the C3H6/NOx ratio of 32.2-44.9 (ppbC/ppb). The initial C3H6/NOx concentration ratio considerably impacted the formation of SOA, in which the amount of SOA increased from 12.1 to 47.9 μg m-3 exponentially as the ratio decreased from 46.5 to 6.3 with an important point of the ratio value of 11. At the ratio of less than 11 in the regime under the control of C3H6, SOA concentrations decreased considerably with increasing ratio, whereas at the ratio value of larger than 11 in the NOx controlled regime, SOA slightly decreased with increasing ratio. From combination of the analysis of different functional groups of particles by IR spectra and ESI-Exactive-Orbitrap mass spectrometer, the constituents of SOA were identified to be hydroperoxides (e.g. HOCH2CCl(CH3)OOH), esters (e.g. CH2ClC(O)OCHClCHO), organic nitrates (e.g. HO2CH(CH2Cl)C(O)OCCl(CH2Cl)C(O)OCHClCH2ONO2), etc. Furthermore, a liquid-phase mechanism of SOA formation has been proposed in this study.

  5. Ethylene glycol emissions from on-road vehicles: implications for aqueous phase secondary organic aerosol formation

    NASA Astrophysics Data System (ADS)

    Wood, E. C.; Knighton, W. B.; Fortner, E.; Herndon, S. C.; Onasch, T. B.; Franklin, J.; Harley, R. A.; Gentner, D. R.; Goldstein, A. H.

    2012-12-01

    Ethylene glycol (HOCH2CH2OH), used as an engine coolant for most on-road vehicles, is an intermediate volatility organic compound (IVOC) with a high Henry's Law Coefficient (kH > 10,000 M atm-1) . Oxidation of ethylene glycol, especially in the atmospheric aqueous phase (clouds, fog, wet aerosol), can lead to the formation of glycolaldehyde, oxalic acid, and ultimately secondary organic aerosol. We present measurements of unexpectedly high ethylene glycol emissions in the Caldecott Tunnel near San Francisco (Summer 2010) and the Washburn Tunnel near Houston (Spring 2009). Ethylene glycol was detected using a proton-transfer reaction mass spectrometer (PTR-MS) at m/z = 45, which is usually interpreted as acetaldehyde. Although not necessarily a tailpipe emission, effective fuel-based emission factors are calculated using the carbon balance method and range from 50 to 400 mg ethylene glycol per kg fuel. Total US and global emissions are estimated using these emission factors and fuel consumption rates and are compared to previous model estimates of ethylene glycol emissions (e.g., the Regional Atmospheric Chemistry Model). Compared to biogenically emitted isoprene, ethylene glycol is likely a minor source of glycolaldehyde globally, but may contribute significantly to glycolaldehyde, oxalate and SOA formation in areas dominated by urban emissions.

  6. Secondary organic aerosol formation and composition from the photo-oxidation of methyl chavicol (estragole)

    NASA Astrophysics Data System (ADS)

    Pereira, K. L.; Hamilton, J. F.; Rickard, A. R.; Bloss, W. J.; Alam, M. S.; Camredon, M.; Muñoz, A.; Vásquez, M.; Borrás, E.; Ródenas, M.

    2013-12-01

    The increasing demand for palm oil for uses in biofuel and food products is leading to rapid expansion of oil palm agriculture. Methyl chavicol (also known as estragole and 1-allyl-4-methoxybenzene) is an oxygenated biogenic volatile organic compound that was recently identified as the main floral emission from an oil palm plantation in Malaysian Borneo. The emissions of methyl chavicol observed may impact regional atmospheric chemistry, but little is known of its ability to form secondary organic aerosol (SOA). The photo-oxidation of methyl chavicol was investigated at the European Photoreactor chamber as a part of the atmospheric chemistry of methyl chavicol (ATMECH) project. Aerosol samples were collected using a particle into liquid sampler (PILS) and analysed offline using an extensive range of instruments including; high performance liquid chromatography mass spectrometry (HPLC-ITMS), high performance liquid chromatography quadrupole time-of-flight mass spectrometry (HPLC-QTOFMS) and Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS). The SOA yield was determined as 18-29% depending on initial precursor (VOC : NOx) mixing ratios. In total, 59 SOA compounds were observed and the structures of 10 compounds have been identified using high resolution tandem mass spectrometry. The addition of hydroxyl and/or nitro functional groups to the aromatic ring appears to be an important mechanistic pathway for aerosol formation. This results in the formation of compounds with both low volatility and high O : C ratios, where functionalisation rather than fragmentation is mainly observed as a~result of the stability of the ring. The SOA species observed can be characterized as semi-volatile to low volatile oxygenated organic aerosol (SVOOA and LVOOA) components and therefore may be important in aerosol formation and growth.

  7. Secondary organic aerosol formation and composition from the photo-oxidation of methyl chavicol (estragole)

    NASA Astrophysics Data System (ADS)

    Pereira, K. L.; Hamilton, J. F.; Rickard, A. R.; Bloss, W. J.; Alam, M. S.; Camredon, M.; Muñoz, A.; Vázquez, M.; Borrás, E.; Ródenas, M.

    2014-06-01

    The increasing demand for palm oil for uses in biofuel and food products is leading to rapid expansion of oil palm agriculture. Methyl chavicol (also known as estragole and 1-allyl-4-methoxybenzene) is an oxygenated biogenic volatile organic compound (VOC) that was recently identified as the main floral emission from an oil palm plantation in Malaysian Borneo. The emissions of methyl chavicol observed may impact regional atmospheric chemistry, but little is known of its ability to form secondary organic aerosol (SOA). The photo-oxidation of methyl chavicol was investigated at the European Photoreactor chamber as a part of the atmospheric chemistry of methyl chavicol (ATMECH) project. Aerosol samples were collected using a particle into liquid sampler (PILS) and analysed offline using an extensive range of instruments including; high-performance liquid chromatography mass spectrometry (HPLC-ITMS), high-performance liquid chromatography quadrupole time-of-flight mass spectrometry (HPLC-QTOFMS) and Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS). The SOA yield was determined as 18 and 29% for an initial VOC mixing ratio of 212 and 460 ppbv (parts per billion by volume) respectively; using a VOC:NOx ratio of ~5:1. In total, 59 SOA compounds were observed and the structures of 10 compounds have been identified using high-resolution tandem mass spectrometry. The addition of hydroxyl and/or nitro-functional groups to the aromatic ring appears to be an important mechanistic pathway for aerosol formation. This results in the formation of compounds with both low volatility and high O:C ratios, where functionalisation rather than fragmentation is mainly observed as a result of the stability of the ring. The SOA species observed can be characterised as semi-volatile to low-volatility oxygenated organic aerosol (SVOOA and LVOOA) components and therefore may be important in aerosol formation and growth.

  8. Experimental investigation of cesium mobility in the course of secondary mineral formations in Hanford sediment columns at 50 degrees C.

    PubMed

    Mashal, Kholoud Y; Cetiner, Ziya S

    2010-10-01

    Formation of secondary minerals and Cs mobility in Hanford sediments were investigated under conditions similar to the Hanford tank leak in a dynamic flow system at 50 degrees C. The objectives were to (1) examine the nature and locations of secondary mineral phases precipitated in the sediments and (2) quantify the amount of Cs retained by the sediment matrix at 50 degrees C. To this end, Hanford sediments were packed into 10-cm long columns and leached with simulated tank waste consisting of 1.4 M NaOH, 0.125 M NaAlO(2), 3.7 M NaNO(3), and 1.3 x 10(-4) M Cs at 50 degrees C. Compositions of outflow solution were monitored with time for up to 25 days, and the columns were then segmented into four 2.5-cm long layers. The colloidal fraction in these segments was characterized in terms of mineralogy, particle morphology, Cs content, and short-range Al and Si structure. It was observed that cancrinite and sodalite precipitated at 50 degrees C. Approximately 53% Cs was retained in the column treated by the simulated tank waste at this temperature. Cesium retention in the column was lowered in the high ionic strength solution due to competition from Na for the exchange sites. This can be explained by alteration of distribution and number of sorption sites which reduces the selectivity of Cs for Na, and through the formation of cancrinite and sodalite. The formation of hydroxide complexes in highly alkaline solutions could also contribute to relatively poor retention of Cs by hindering ion exchange mechanism.

  9. Fluid-flow, diagenesis and generation of secondary porosity-permeability in the Cretaceous Jandaira Formation, Brazil - an analogue of karstified carbonate reservoirs

    NASA Astrophysics Data System (ADS)

    Bezerra, F. H.; Cazarin, C. L.; Srivastava, N. K.

    2017-12-01

    This study investigates the diagenetic processes that generated secondary porosity-permeability in carbonates. Our study area is the Jandaira Formation, a post-rift unit, 50-700 m thick, which occurs over an area of 70 x 260 km in the Potiguar Basin, Equatorial margin of Brazil. The Jandaira Formation formed in the Turonian-Campanian and is the major exposed Cretaceous carbonate platform in the eastern continental margin of South America. Little folding and nearly flat-lying layers characterize this unit. We used a multidisciplinary approach, which included drone imagery, petrographic, petrophysical, petrological, and structural studies. Our results indicate that several levels of dissolution occurred in mudstone, grainstone, and wackestone facies along faults, fractures, and bedding planes. Fracture and faults provided vertical leaching pathways and sedimentary bedding provided horizontal pathways of increased secondary porosity and permeability. Dissolution resulted in a multi-scale karst system that could reach voids 5 m wide and 1 km long. Dissolution mostly affect the dolomitized sedimentary facies in the form of vugular, moldic, interparticular, and intercrystalline porosity. It also generated a new modified facies that we defined as karstified facies. Dissolution increased permeability in carbonate rocks from primary values of 0.0-0.94 mD to as much as 1370.11 mD. Micritization, lixiviation of evaporites, meteoric water infiltration and dolomitization during late diagenesis could have triggered dissolution processes. The Jandaira Formation serves as an analog of fractured and karstified carbonate reservoirs, where faults, joints, and bedding acted as pathways of high permeability.

  10. Effects of salinity and the extent of water on supercritical CO2-induced phlogopite dissolution and secondary mineral formation.

    PubMed

    Shao, Hongbo; Ray, Jessica R; Jun, Young-Shin

    2011-02-15

    To ensure the viability of geologic CO2 sequestration (GCS), we need a holistic understanding of reactions at supercritical CO2 (scCO2)-saline water-rock interfaces and the environmental factors affecting these interactions. This research investigated the effects of salinity and the extent of water on the dissolution and surface morphological changes of phlogopite [KMg2.87Si3.07Al1.23O10(F,OH)2], a model clay mineral in potential GCS sites. Salinity enhanced the dissolution of phlogopite and affected the location, shape, size, and phase of secondary minerals. In low salinity solutions, nanoscale particles of secondary minerals formed much faster, and there were more nanoparticles than in high salinity solutions. The effect of water extent was investigated by comparing scCO2-H2O(g)-phlogopite and scCO2-H2O(l)-phlogopite interactions. Experimental results suggested that the presence of a thin water film adsorbed on the phlogopite surface caused the formation of dissolution pits and a surface coating of secondary mineral phases that could change the physical properties of rocks. These results provide new information for understanding reactions at scCO2-saline water-rock interfaces in deep saline aquifers and will help design secure and environmentally sustainable CO2 sequestration projects.

  11. Time-resolved analysis of primary volatile emissions and secondary aerosol formation potential from a small-scale pellet boiler

    NASA Astrophysics Data System (ADS)

    Czech, Hendryk; Pieber, Simone M.; Tiitta, Petri; Sippula, Olli; Kortelainen, Miika; Lamberg, Heikki; Grigonyte, Julija; Streibel, Thorsten; Prévôt, André S. H.; Jokiniemi, Jorma; Zimmermann, Ralf

    2017-06-01

    Small-scale pellet boilers and stoves became popular as a wood combustion appliance for domestic heating in Europe, North America and Asia due to economic and environmental aspects. Therefore, an increasing contribution of pellet boilers to air pollution is expected despite their general high combustion efficiency. As emissions of primary organic aerosol (POA) and permanent gases of pellet boilers are well investigated, the scope of this study was to investigate the volatile organic emissions and the formation potential of secondary aerosols for this type of appliance. Fresh and aged emissions were analysed by a soot-particle aerosol time-of-flight mass spectrometry (SP-AMS) and the molecular composition of the volatile precursors with single-photon ionisation time-of-flight mass spectrometry (SPI-TOFMS) at different pellet boiler operation conditions. Organic emissions in the gas phase were dominated by unsaturated hydrocarbons while wood-specific VOCs, e.g. phenolic species or substituted furans, were only detected during the starting phase. Furthermore, organic emissions in the gas phase were found to correlate with fuel grade and combustion technology in terms of secondary air supply. Secondary organic aerosols of optimised pellet boiler conditions (OPT, state-of-the-art combustion appliance) and reduced secondary air supply (RSA, used as a proxy for pellet boilers of older type) were studied by simulating atmospheric ageing in a Potential Aerosol Mass (PAM) flow reactor. Different increases in OA mass (55% for OPT, 102% for RSA), associated with higher average carbon oxidation state and O:C, could be observed in a PAM chamber experiment. Finally, it was found that derived SOA yields and emission factors were distinctly lower than reported for log wood stoves.

  12. Mechanisms for secondary eyewall formation, and cold-air damming: Tropical cyclone interactions

    NASA Astrophysics Data System (ADS)

    Garcia-Rivera, Jose Manuel

    This dissertation consists of two topics, the mechanisms leading to secondary eyewall formation in tropical cyclones, and effects of tropical cyclone---cold-air interactions on heavy precipitation. The first research topic involves a proposed coupled mechanism for secondary eyewall formation (SEF; initiation of an eyewall replacement cycle), using a WRF-ARW simulation of Hurricane Katrina (2005). The storm underwent a series of structural changes that were deemed necessary for the cycle to begin. These included a significant increase of rainband activity in the SEF region and the eventual vertical coupling of azimuthal-mean updrafts that led to cycle initiation. Increased rainband activity outside the primary eyewall in the hours before was mostly related to an intensifying main feeder band. Close to initiation, an updraft (explained by a pre-existing hypothesis) emerged outside the primary eyewall near the top of the boundary layer (BL). This updraft then intensified and extended both upward and outward, while the storm intensified and approached SEF. Eventually, the updraft coupled with the upward motion associated with rainband-related convection near the SEF radius. Once the alignment occurred, the deep updraft quickly organized to support deep convection that led to SEF within hours of initiation. The coupling of updrafts emanating from the BL with the environmental upward motion associated with the pre-existing rainband activity is proposed to be the key for SEF initiation in this case. The second topic investigates the interactions between an Appalachian cold-air damming event and the near-passage of Tropical Storm Kyle (2002) along the coastal Carolinas, as assessed by using a numerical weather prediction model. While the storm moved along the coastline, it began extra-tropical transition, bringing heavy rains to both the coastal region and inland towards the Piedmont of North Carolina. Our goal is to quantify the effects of both interacting weather systems

  13. Wood formation in Angiosperms.

    PubMed

    Déjardin, Annabelle; Laurans, Françoise; Arnaud, Dominique; Breton, Christian; Pilate, Gilles; Leplé, Jean-Charles

    2010-04-01

    Wood formation is a complex biological process, involving five major developmental steps, including (1) cell division from a secondary meristem called the vascular cambium, (2) cell expansion (cell elongation and radial enlargement), (3) secondary cell wall deposition, (4) programmed cell death, and (5) heartwood formation. Thanks to the development of genomic studies in woody species, as well as genetic engineering, recent progress has been made in the understanding of the molecular mechanisms underlying wood formation. In this review, we will focus on two different aspects, the lignification process and the control of microfibril angle in the cell wall of wood fibres, as they are both key features of wood material properties. Copyright (c) 2010 Académie des sciences. Published by Elsevier SAS. All rights reserved.

  14. Characterization of xylan in the early stages of secondary cell wall formation in tobacco bright yellow-2 cells.

    PubMed

    Ishii, Tadashi; Matsuoka, Keita; Ono, Hiroshi; Ohnishi-Kameyama, Mayumi; Yaoi, Katsuro; Nakano, Yoshimi; Ohtani, Misato; Demura, Taku; Iwai, Hiroaki; Satoh, Shinobu

    2017-11-15

    The major polysaccharides present in the primary and secondary walls surrounding plant cells have been well characterized. However, our knowledge of the early stages of secondary wall formation is limited. To address this, cell walls were isolated from differentiating xylem vessel elements of tobacco bright yellow-2 (BY-2) cells induced by VASCULAR-RELATED NAC-DOMAIN7 (VND7). The walls of induced VND7-VP16-GR BY-2 cells consisted of cellulose, pectic polysaccharides, hemicelluloses, and lignin, and contained more xylan and cellulose compared with non-transformed BY-2 and uninduced VND7-VP16-GR BY-2 cells. A reducing end sequence of xylan containing rhamnose and galaturonic acid- residues is present in the walls of induced, uninduced, and non-transformed BY-2 cells. Glucuronic acid residues in xylan from walls of induced cells are O-methylated, while those of xylan in non-transformed BY-2 and uninduced cells are not. Our results show that xylan changes in chemical structure and amounts during the early stages of xylem differentiation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Investigation of Secondary Craters in the Saturnian System

    NASA Astrophysics Data System (ADS)

    Hoogenboom, T.; Schenk, P.; White, O. L.

    2012-03-01

    To derive accurate ages using impact craters, the impact source must be determined. We investigate secondary crater size, frequency, distribution, formation, and crater chain formation on icy satellites throughout the Jupiter and Saturn systems.

  16. Secondary organic aerosol formation from ambient air in an oxidation flow reactor in central Amazonia

    NASA Astrophysics Data System (ADS)

    Palm, Brett B.; de Sá, Suzane S.; Day, Douglas A.; Campuzano-Jost, Pedro; Hu, Weiwei; Seco, Roger; Sjostedt, Steven J.; Park, Jeong-Hoo; Guenther, Alex B.; Kim, Saewung; Brito, Joel; Wurm, Florian; Artaxo, Paulo; Thalman, Ryan; Wang, Jian; Yee, Lindsay D.; Wernis, Rebecca; Isaacman-VanWertz, Gabriel; Goldstein, Allen H.; Liu, Yingjun; Springston, Stephen R.; Souza, Rodrigo; Newburn, Matt K.; Lizabeth Alexander, M.; Martin, Scot T.; Jimenez, Jose L.

    2018-01-01

    Secondary organic aerosol (SOA) formation from ambient air was studied using an oxidation flow reactor (OFR) coupled to an aerosol mass spectrometer (AMS) during both the wet and dry seasons at the Observations and Modeling of the Green Ocean Amazon (GoAmazon2014/5) field campaign. Measurements were made at two sites downwind of the city of Manaus, Brazil. Ambient air was oxidized in the OFR using variable concentrations of either OH or O3, over ranges from hours to days (O3) or weeks (OH) of equivalent atmospheric aging. The amount of SOA formed in the OFR ranged from 0 to as much as 10 µg m-3, depending on the amount of SOA precursor gases in ambient air. Typically, more SOA was formed during nighttime than daytime, and more from OH than from O3 oxidation. SOA yields of individual organic precursors under OFR conditions were measured by standard addition into ambient air and were confirmed to be consistent with published environmental chamber-derived SOA yields. Positive matrix factorization of organic aerosol (OA) after OH oxidation showed formation of typical oxidized OA factors and a loss of primary OA factors as OH aging increased. After OH oxidation in the OFR, the hygroscopicity of the OA increased with increasing elemental O : C up to O : C ˜ 1.0, and then decreased as O : C increased further. Possible reasons for this decrease are discussed. The measured SOA formation was compared to the amount predicted from the concentrations of measured ambient SOA precursors and their SOA yields. While measured ambient precursors were sufficient to explain the amount of SOA formed from O3, they could only explain 10-50 % of the SOA formed from OH. This is consistent with previous OFR studies, which showed that typically unmeasured semivolatile and intermediate volatility gases (that tend to lack C = C bonds) are present in ambient air and can explain such additional SOA formation. To investigate the sources of the unmeasured SOA-forming gases during this campaign

  17. Effects of meteorology and secondary particle formation on visibility during heavy haze events in Beijing, China.

    PubMed

    Zhang, Qiang; Quan, Jiannong; Tie, Xuexi; Li, Xia; Liu, Quan; Gao, Yang; Zhao, Delong

    2015-01-01

    The causes of haze formation in Beijing, China were analyzed based on a comprehensive measurement, including PBL (planetary boundary layer), aerosol composition and concentrations, and several important meteorological parameters such as visibility, RH (relative humidity), and wind speed/direction. The measurement was conducted in an urban location from Nov. 16, 2012 to Jan. 15, 2013. During the period, the visibility varied from >20 km to less than a kilometer, with a minimum visibility of 667 m, causing 16 haze occurrences. During the haze occurrences, the wind speeds were less than 1m/s, and the concentrations of PM2.5 (particle matter with radius less than 2.5 μm) were often exceeded 200 μg/m(3). The correlation between PM2.5 concentration and visibility under different RH values shows that visibility was exponentially decreased with the increase of PM2.5 concentrations when RH was less than 80%. However, when RH was higher than 80%, the relationship was no longer to follow the exponentially decreasing trend, and the visibility maintained in very low values, even with low PM2.5 concentrations. Under this condition, the hygroscopic growth of particles played important roles, and a large amount of water vapor acted as particle matter (PM) for the reduction of visibility. The variations of meteorological parameters (RH, PBL heights, and WS (wind speed)), chemical species in gas-phase (CO, O3, SO2, and NOx), and gas-phase to particle-phase conversions under different visibility ranges were analyzed. The results show that from high visibility (>20 km) to low visibility (<2 km), the averaged PBL decreased from 1.24 km to 0.53 km; wind speeds reduced from 1m/s to 0.5m/s; and CO increased from 0.5 ppmv to 4.0 ppmv, suggesting that weaker transport/diffusion caused the haze occurrences. This study also found that the formation of SPM (secondary particle matter) was accelerated in the haze events. The conversions between SO2 and SO4 as well as NOx to NO3(-) increased

  18. Effects of oxyanions, natural organic matter, and bacterial cell numbers on the bioreduction of lepidocrocite ({gamma}-FeOOH) and the formation of secondary mineralization products.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    O'Loughlin, E. J.; Gorski, C. A.; Scherer, M. M.

    Microbial reduction of Fe(III) oxides results in the production of Fe(II) and may lead to the subsequent formation of Fe(II)-bearing secondary mineralization products including magnetite, siderite, vivianite, chukanovite (ferrous hydroxy carbonate (FHC)), and green rust; however, the factors controlling the formation of specific Fe(II) phases are often not well-defined. This study examined effects of (i) a range of inorganic oxyanions (arsenate, borate, molybdate, phosphate, silicate, and tungstate), (ii) natural organic matter (citrate, oxalate, microbial extracellular polymeric substances [EPS], and humic substances), and (iii) the type and number of dissimilatory iron-reducing bacteria on the bioreduction of lepidocrocite and formation of Fe(II)-bearingmore » secondary mineralization products. The bioreduction kinetics clustered into two distinct Fe(II) production profiles. 'Fast' Fe(II) production kinetics [19-24 mM Fe(II) d-1] were accompanied by formation of magnetite and FHC in the unamended control and in systems amended with borate, oxalate, gellan EPS, or Pony Lake fulvic acid or having 'low' cell numbers. Systems amended with arsenate, citrate, molybdate, phosphate, silicate, tungstate, EPS from Shewanella putrefaciens CN32, or humic substances derived from terrestrial plant material or with 'high' cell numbers exhibited comparatively slow Fe(II) production kinetics [1.8-4.0 mM Fe(II) d-1] and the formation of green rust. The results are consistent with a conceptual model whereby competitive sorption of more strongly bound anions blocks access of bacterial cells and reduced electron-shuttling compounds to sites on the iron oxide surface, thereby limiting the rate of bioreduction.« less

  19. Secondary missile injury from lightning strike.

    PubMed

    Blumenthal, Ryan

    2012-03-01

    A 48-year-old-woman was struck dead by lightning on October 24, 2010, in Pretoria, South Africa. The cause of death was due to direct lightning strike. Examination showed secondary missile injury on her legs. This secondary missile (shrapnel) injury was caused by the lightning striking the concrete pavement next to her. Small pieces of concrete were located embedded within the shrapnel wounds. This case report represents the first documented case of secondary missile formation (shrapnel injury) due to lightning strike in the literature.

  20. A data seamless interaction scheme between electric power secondary business systems

    NASA Astrophysics Data System (ADS)

    Ai, Wenkai; Qian, Feng

    2018-03-01

    At present, the data interaction of electric power secondary business systems is very high, and it is not universal to develop programs when data interaction is carried out by different manufacturers' electric power secondary business systems. There are different interaction schemes for electric power secondary business systems with different manufacturers, which lead to high development cost, low reusability and high maintenance difficulty. This paper introduces a new data seamless interaction scheme between electric power secondary business systems. The scheme adopts the international common Java message service protocol as the transmission protocol, adopts the common JavaScript object symbol format as the data interactive format, unified electric power secondary business systems data interactive way, improve reusability, reduce complexity, monitor the operation of the electric power secondary business systems construction has laid a solid foundation.

  1. Aqueous photooxidation of ambient Po Valley Italy air samples: Insights into secondary organic aerosol formation

    NASA Astrophysics Data System (ADS)

    Kirkland, J. R.; Lim, Y. B.; Sullivan, A. P.; Decesari, S.; Facchini, C.; Collett, J. L.; Keutsch, F. N.; Turpin, B. J.

    2012-12-01

    In this work, we conducted aqueous photooxidation experiments with ambient samples in order to develop insights concerning the formation of secondary organic aerosol through gas followed by aqueous chemistry (SOAaq). Water-soluble organics (e.g., glyoxal, methylglyoxal, glycolaldehyde, acetic acid, acetone) are formed through gas phase oxidation of alkene and aromatic emissions of anthropogenic and biogenic origin. Their further oxidation in clouds, fogs and wet aerosols can form lower volatility products (e.g., oligomers, organic acids) that remain in the particle phase after water evaporation, thus producing SOA. The aqueous OH radical oxidation of several individual potentially important precursors has been studied in the laboratory. In this work, we used a mist-chamber apparatus to collect atmospheric mixtures of water-soluble gases from the ambient air at San Pietro Capofiume, Italy during the PEGASOS field campaign. We measured the concentration dynamics after addition of OH radicals, in order to develop new insights regarding formation of SOA through aqueous chemistry. Specifically, batch aqueous reactions were conducted with 33 ml mist-chamber samples (TOC ~ 50-100μM) and OH radicals (~10-12M) in a new low-volume aqueous reaction vessel. OH radicals were formed in-situ, continuously by H2O2 photolysis. Products were analyzed by ion chromatography (IC), electrospray ionization mass spectrometry (ESI-MS +/-), and ESI-MS with IC pre-separation (IC/ESI-MS-). Reproducible formation of pyruvate and oxalate were observed both by IC and ESI-MS. These compounds are known to form from aldehyde oxidation in the aqueous phase. New insights regarding the aqueous chemistry of these "more atmospherically-realistic" experiments will be discussed.

  2. Monocarboxylic and dicarboxylic acids over oceans from the East China Sea to the Arctic Ocean: Roles of ocean emissions, continental input and secondary formation.

    PubMed

    Hu, Qihou; Xie, Zhouqing; Wang, Xinming; Kang, Hui; Zhang, Yuqing; Ding, Xiang; Zhang, Pengfei

    2018-05-30

    Organic acids are major components in marine organic aerosols. Many studies on the occurrence, sources and sinks of organic acids over oceans in the low and middle latitudes have been conducted. However, the understanding of relative contributions of specific sources to organic acids over oceans, especially in the high latitudes, is still inadequate. This study measured organic acids, including C 14:0 - C 32:0 saturated monocarboxylic acids (MCAs), C 16:1 , C 18:1 and C 18:2 unsaturated MCAs, and di-C 4 - di-C 10 dicarboxylic acids (DCAs), in the marine boundary layer from the East China Sea to the Arctic Ocean during the 3rd Chinese Arctic Research Expedition (CHINARE 08). The average concentrations were 18 ± 16 ng/m 3 and 11 ± 5.4 ng/m 3 for ΣMCA and ΣDCA, respectively. The levels of saturated MCAs were much higher than those of unsaturated DCAs, with peaks at C 16:0 , C 18:0 and C 14:0 . DCAs peaked at di-C 4 , followed by di-C 9 and di-C 8 . Concentrations of MCAs and DCAs generally decreased with increasing latitudes. Sources of MCAs and DCAs were further investigated using principal component analysis with a multiple linear regression (PCA-MLR) model. Overall, carboxylic acids originated from ocean emissions, continental input (including biomass burning, anthropogenic emissions and terrestrial plant emissions), and secondary formation. All the five sources contributed to MCAs with ocean emissions as the predominant source (48%), followed by biomass burning (20%). In contrast, only 3 sources (i.e., secondary formation (50%), anthropogenic emissions (41%) and biomass burning (9%)) contributed to DCAs. Furthermore, the sources varied with regions. Over the Arctic Ocean, only secondary formation and anthropogenic emissions contributed to MCAs and DCAs. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. [Effect of temperature on activity of Acidithiobacillus ferrooxidan and formation of biogenic secondary iron minerals].

    PubMed

    Song, Yong-Wei; Zhao, Bo-Wen; Huo, Min-Bo; Cui, Chun-Hong; Zhou, Li-Xiang

    2013-08-01

    In this study, batch experiments were performed to investigate the effect of temperature on the Fe (II) oxidation and the formation of biogenic secondary iron minerals by Acidithiobacillus ferrooxidan. Results showed that the low temperature significantly inhibited the oxidation activity of A. ferrooxidan. In the FeSO4-H2O biological oxidation system facilitated by A. ferrooxidan, it was found that after 5 days culture, the oxidation rates of Fe (II) in treatments of 10 degrees C and 28 degrees C were 11.81% and 100%, respectively. In addition, it rapidly rose to 95.10% when the temperature was adjusted from 10 degrees C (cultured for 7 days) to 28 degrees C in 1 day, and the maximum oxidation rates were as follows: 10 degrees C (cultured for 7 days) +28 degrees C (2.25 h(-1)) > 28 degrees C (1.42 h(-1)) >10 degrees C (0.81 h(-1)). Furthermore, the XRD patterns showed that the lower Fe (III) supply rate was more conducive to the formation of amorphous schwertmannite in 9K medium at 10 degrees C. Correspondingly, the generation of amorphous schwertmannite was preceded to ihleite at 28 degrees C, and the crystallinity degree of ihleite was getting better with the extension of culture time. Combined with the SEM characteristics, it was judged that the 28 degrees C sample contained jarosite and schwertmannite.

  4. Secondary organic aerosol formation in biomass-burning plumes: theoretical analysis of lab studies and ambient plumes

    NASA Astrophysics Data System (ADS)

    Bian, Qijing; Jathar, Shantanu H.; Kodros, John K.; Barsanti, Kelley C.; Hatch, Lindsay E.; May, Andrew A.; Kreidenweis, Sonia M.; Pierce, Jeffrey R.

    2017-04-01

    Secondary organic aerosol (SOA) has been shown to form in biomass-burning emissions in laboratory and field studies. However, there is significant variability among studies in mass enhancement, which could be due to differences in fuels, fire conditions, dilution, and/or limitations of laboratory experiments and observations. This study focuses on understanding processes affecting biomass-burning SOA formation in laboratory smog-chamber experiments and in ambient plumes. Vapor wall losses have been demonstrated to be an important factor that can suppress SOA formation in laboratory studies of traditional SOA precursors; however, impacts of vapor wall losses on biomass-burning SOA have not yet been investigated. We use an aerosol-microphysical model that includes representations of volatility and oxidation chemistry to estimate the influence of vapor wall loss on SOA formation observed in the FLAME III smog-chamber studies. Our simulations with base-case assumptions for chemistry and wall loss predict a mean OA mass enhancement (the ratio of final to initial OA mass, corrected for particle-phase wall losses) of 1.8 across all experiments when vapor wall losses are modeled, roughly matching the mean observed enhancement during FLAME III. The mean OA enhancement increases to over 3 when vapor wall losses are turned off, implying that vapor wall losses reduce the apparent SOA formation. We find that this decrease in the apparent SOA formation due to vapor wall losses is robust across the ranges of uncertainties in the key model assumptions for wall-loss and mass-transfer coefficients and chemical mechanisms.We then apply similar assumptions regarding SOA formation chemistry and physics to smoke emitted into the atmosphere. In ambient plumes, the plume dilution rate impacts the organic partitioning between the gas and particle phases, which may impact the potential for SOA to form as well as the rate of SOA formation. We add Gaussian dispersion to our aerosol

  5. Secondary organic aerosol formation in biomass-burning plumes: theoretical analysis of lab studies and ambient plumes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bian, Qijing; Jathar, Shantanu H.; Kodros, John K.

    Secondary organic aerosol (SOA) has been shown to form in biomass-burning emissions in laboratory and field studies. However, there is significant variability among studies in mass enhancement, which could be due to differences in fuels, fire conditions, dilution, and/or limitations of laboratory experiments and observations. This study focuses on understanding processes affecting biomass-burning SOA formation in laboratory smog-chamber experiments and in ambient plumes. Vapor wall losses have been demonstrated to be an important factor that can suppress SOA formation in laboratory studies of traditional SOA precursors; however, impacts of vapor wall losses on biomass-burning SOA have not yet been investigated.more » We use an aerosol-microphysical model that includes representations of volatility and oxidation chemistry to estimate the influence of vapor wall loss on SOA formation observed in the FLAME III smog-chamber studies. Our simulations with base-case assumptions for chemistry and wall loss predict a mean OA mass enhancement (the ratio of final to initial OA mass, corrected for particle-phase wall losses) of 1.8 across all experiments when vapor wall losses are modeled, roughly matching the mean observed enhancement during FLAME III. The mean OA enhancement increases to over 3 when vapor wall losses are turned off, implying that vapor wall losses reduce the apparent SOA formation. We find that this decrease in the apparent SOA formation due to vapor wall losses is robust across the ranges of uncertainties in the key model assumptions for wall-loss and mass-transfer coefficients and chemical mechanisms. We then apply similar assumptions regarding SOA formation chemistry and physics to smoke emitted into the atmosphere. In ambient plumes, the plume dilution rate impacts the organic partitioning between the gas and particle phases, which may impact the potential for SOA to form as well as the rate of SOA formation. We add Gaussian dispersion to our aerosol

  6. Secondary organic aerosol formation in biomass-burning plumes: theoretical analysis of lab studies and ambient plumes

    DOE PAGES

    Bian, Qijing; Jathar, Shantanu H.; Kodros, John K.; ...

    2017-04-28

    Secondary organic aerosol (SOA) has been shown to form in biomass-burning emissions in laboratory and field studies. However, there is significant variability among studies in mass enhancement, which could be due to differences in fuels, fire conditions, dilution, and/or limitations of laboratory experiments and observations. This study focuses on understanding processes affecting biomass-burning SOA formation in laboratory smog-chamber experiments and in ambient plumes. Vapor wall losses have been demonstrated to be an important factor that can suppress SOA formation in laboratory studies of traditional SOA precursors; however, impacts of vapor wall losses on biomass-burning SOA have not yet been investigated.more » We use an aerosol-microphysical model that includes representations of volatility and oxidation chemistry to estimate the influence of vapor wall loss on SOA formation observed in the FLAME III smog-chamber studies. Our simulations with base-case assumptions for chemistry and wall loss predict a mean OA mass enhancement (the ratio of final to initial OA mass, corrected for particle-phase wall losses) of 1.8 across all experiments when vapor wall losses are modeled, roughly matching the mean observed enhancement during FLAME III. The mean OA enhancement increases to over 3 when vapor wall losses are turned off, implying that vapor wall losses reduce the apparent SOA formation. We find that this decrease in the apparent SOA formation due to vapor wall losses is robust across the ranges of uncertainties in the key model assumptions for wall-loss and mass-transfer coefficients and chemical mechanisms. We then apply similar assumptions regarding SOA formation chemistry and physics to smoke emitted into the atmosphere. In ambient plumes, the plume dilution rate impacts the organic partitioning between the gas and particle phases, which may impact the potential for SOA to form as well as the rate of SOA formation. We add Gaussian dispersion to our aerosol

  7. FORMATION MECHANISMS FOR SECONDARY ORGANIC AEROSOL IN AMBIENT AIR

    EPA Science Inventory

    An laboratory and field research program is underway at the NERL to characterize secondary organic carbon in PM2.5 which is formed through chemical reactions in the atmosphere. Information from this study will provide critical data needed to improve the treatment of SO...

  8. Effect of heterogeneous aqueous reactions on the secondary formation of inorganic aerosols during haze events

    DOE PAGES

    Quan, Jiannong; Liu, Yangang; Liu, Quan; ...

    2015-09-30

    In this study, the effect of heterogeneous aqueous reactions on the secondary formation of inorganic aerosols during haze events was investigated by analysis of comprehensive measurements of aerosol composition and concentrations [e.g., particular matters (PM 2.5), nitrate (NO 3), sulfate (SO 4), ammonium (NH 4)], gas-phase precursors [e.g., nitrogen oxides (NOx), sulfur dioxide (SO 2), and ozone (O 3)], and relevant meteorological parameters [e.g., visibility and relative humidity (RH)]. The measurements were conducted in Beijing, China from Sep. 07, 2012 to Jan. 16, 2013. The results show that the conversion ratios of N from NOx to nitrate (N ratio) andmore » S from SO 2 to sulfate (S ratio) both significantly increased in haze events, suggesting enhanced conversions from NOx and SO 2 to their corresponding particle phases in the late haze period. Further analysis shows that N ratio and S ratio increased with increasing RH, with N ratio and S ratio being only 0.04 and 0.03, respectively, when RH < 40%, and increasing up to 0.16 and 0.12 when RH reached 60–80%, respectively. The enhanced conversion ratios of N and S in the late haze period is likely due to heterogeneous aqueous reactions, because solar radiation and thus the photochemical capacity are reduced by the increases in aerosols and RH. This point was further affirmed by the relationships of N ratio and S ratio to O 3: the conversion ratios increase with decreasing O 3 concentration when O 3 concentration is lower than <15 ppb but increased with increasing O 3 when O 3 concentration is higher than 15 ppb. The results suggest that heterogeneous aqueous reactions likely changed aerosols and their precursors during the haze events: in the beginning of haze events, the precursor gases accumulated quickly due to high emission and low reaction rate; the occurrence of heterogeneous aqueous reactions in the late haze period, together with the accumulated high concentrations of precursor gases such as SO 2 and

  9. Wintertime Secondary Organic Aerosol (SOA) Formation from Oxidation of Volatile Organic Compounds (VOCs) Associated with Oil and Gas Extraction

    NASA Astrophysics Data System (ADS)

    Murphy, S. M.; Soltis, J.; Field, R. A.; Bates, T. S.; Quinn, P.; De Gouw, J. A.; Veres, P. R.; Warneke, C.; Graus, M.; Gilman, J.; Lerner, B. M.; Koss, A.

    2013-12-01

    The Uintah Basin is located in a lightly populated area of Northeastern Utah near Dinosaur National Monument. Oil and gas extraction activities in the basin have dramatically increased in recent years due to the application of hydraulic fracturing. The Uintah Basin has experienced numerous high-ozone events during the past several winters with concentrations often exceeding 100 ppb. PM 2.5 monitoring by the city of Vernal, located at the edge of the basin, have shown wintertime concentrations in excess of the EPA 8-hour national standard, though the source and composition of particulates during these events is unclear. The Energy and Environment - Uintah Basin Winter Ozone Study (E&E UBWOS) was conducted during the winters of 2012 and 2013. During the study, intensive measurements of aerosol composition and speciated VOCs were made at a monitoring site near oil and gas extraction activities. Organic aerosol was found to be a major component of PM 2.5 and organic aerosol formation was highly correlated with the production of secondary VOC's. This correlation suggests that the organic aerosol is secondary in nature even though O:C ratios suggest a less oxidized aerosol than often observed in summertime SOA. The ozone levels and organic aerosol mass during 2012 were much lower than those observed in 2013. Calculations of the aerosol yield during both years will be presented along with an analysis of how well observed yields match predictions based on smog-chamber data. The potential for additional aerosol formation in the system will also be discussed.

  10. Effect of high concentrations of inorganic seed aerosols on secondary organic aerosol formation in the m-xylene/NO x photooxidation system

    NASA Astrophysics Data System (ADS)

    Lu, Zifeng; Hao, Jiming; Takekawa, Hideto; Hu, Lanhua; Li, Junhua

    High concentrations (>15 μm 3 cm -3) of CaSO 4, Ca(NO 3) 2 and (NH 4) 2SO 4 were selected as surrogates of dry neutral, aqueous neutral and dry acidic inorganic seed aerosols, respectively, to study the effects of inorganic seeds on secondary organic aerosol (SOA) formation in irradiated m-xylene/NO x photooxidation systems. The results indicate that neither ozone formation nor SOA formation is significantly affected by the presence of neutral aerosols (both dry CaSO 4 and aqueous Ca(NO 3) 2), even at elevated concentrations. The presence of high concentrations of (NH 4) 2SO 4 aerosols (dry acidic) has no obvious effect on ozone formation, but it does enhance SOA generation and increase SOA yields. In addition, the effect of dry (NH 4) 2SO 4 on SOA yield is found to be positively correlated with the (NH 4) 2SO 4 surface concentration, and the effect is pronounced only when the surface concentration reaches a threshold value. Further, it is proposed that the SOA generation enhancement is achieved by particle-phase heterogeneous reactions induced and catalyzed by the acidity of dry (NH 4) 2SO 4 seed aerosols.

  11. Co-doping of (Bi(0.5)Na(0.5))TiO(3): secondary phase formation and lattice site preference of Co.

    PubMed

    Schmitt, V; Staab, T E M

    2012-11-14

    Bismuth sodium titanate (Bi(0.5)Na(0.5))TiO(3) (BNT) is considered to be one of the most promising lead-free alternatives to piezoelectric lead zirconate titanate (PZT). However, the effect of dopants on the material has so far received little attention from an atomic point of view. In this study we investigated the effects of cobalt-doping on the formation of additional phases and determined the preferred lattice site of cobalt in BNT. The latter was achieved by comparing the measured x-ray absorption near-edge structure (XANES) spectra to numerically calculated spectra of cobalt on various lattice sites in BNT. (Bi(0.5)Na(0.5))TiO(3) + x mol% Co (x = 0.0, 0.5, 1.0, 2.6) was synthesized via solid state reaction. As revealed by SEM backscattering images, a secondary phase formed in all doped specimens. Using both XRD and SEM-EDX, it was identified as Co(2)TiO(4) for dopant levels >0.5 mol%. In addition, a certain amount of cobalt was incorporated into BNT, as shown by electron probe microanalysis. This amount increased with increasing dopant levels, suggesting that an equilibrium forms together with the secondary phase. The XANES experiments revealed that cobalt occupies the octahedral B-site in the BNT perovskite lattice, substituting Ti and promoting the formation of oxygen vacancies in the material.

  12. Secondary Organic Aerosol Formation and Aging in a Flow Reactor in the Forested Southeast US during SOAS

    NASA Astrophysics Data System (ADS)

    Hu, W.; Palm, B. B.; Hacker, L.; Campuzano Jost, P.; Day, D. A.; de Sá, S. S.; Ayres, B. R.; Draper, D.; Fry, J.; Ortega, A. M.; Kiendler-Scharr, A.; Pajunoja, A.; Virtanen, A.; Krechmer, J.; Canagaratna, M. R.; Thompson, S.; Yatavelli, R. L. N.; Stark, H.; Worsnop, D. R.; Martin, S. T.; Farmer, D.; Brown, S. S.; Jimenez, J. L.

    2015-12-01

    A major field campaign (Southern Oxidant and Aerosol Study, SOAS) was conducted in summer 2013 in a forested area in Centreville Supersite, AL (SEARCH network) in the southeast U.S. To investigate secondary organic aerosol (SOA) formation from biogenic volatile organic compounds (BVOCs), 3 oxidation flow reactors (OFR) were used to expose ambient air to oxidants and their output was analyzed by state-of-the-art gas and aerosol instruments including a High-Resolution Aerosol Mass Spectrometer (HR-AMS), a HR Proton-Transfer Reaction Time-of-Flight Mass Spectrometer (PTR-TOFMS), and Two HR-TOF Chemical Ionization Mass Spectrometers (HRToF-CIMS). Ambient air was exposed 24/7 to variable concentrations of each of the 3 main atmospheric oxidants (OH, NO3 radicals and O3) to investigate the oxidation of BVOCs (including isoprene derived epoxydiols, IEPOX) and SOA formation and aging. Effective OH exposures up to 1×1013 molec cm-3 s were achieved, equivalent to over a month of aging in the atmosphere. Multiple oxidation products from isoprene and monoterpenes including small gas-phase acids were observed in OH OFR. High SOA formation of up to 12 μg m-3 above ambient concentrations of 5 μg m-3 was observed under intermediate OH exposures, while very high OH exposures led to destruction of ~30% of ambient OA, indicating shifting contributions of functionalization vs. fragmentation, consistent with results from urban and terpene-dominated environments. The highest SOA enhancements were 3-4 times higher than ambient OA. More SOA is typically formed during nighttime when terpenes are higher and photochemistry is absent, and less during daytime when isoprene is higher, although the IEPOX pathway is suppressed in the OFR. SOA is also observed after exposure of ambient air to O3 or NO3, although the amounts and oxidation levels were lower than for OH. Formation of organic nitrates in the NO3 reaction will also be discussed.A major field campaign (Southern Oxidant and Aerosol

  13. Secondary organic aerosol formation from ambient air in an oxidation flow reactor in central Amazonia

    DOE PAGES

    Palm, Brett B.; de Sá, Suzane S.; Day, Douglas A.; ...

    2018-01-17

    Secondary organic aerosol (SOA) formation from ambient air was studied using an oxidation flow reactor (OFR) coupled to an aerosol mass spectrometer (AMS) during both the wet and dry seasons at the Observations and Modeling of the Green Ocean Amazon (GoAmazon2014/5) field campaign. Measurements were made at two sites downwind of the city of Manaus, Brazil. Ambient air was oxidized in the OFR using variable concentrations of either OH or O 3, over ranges from hours to days (O 3) or weeks (OH) of equivalent atmospheric aging. The amount of SOA formed in the OFR ranged from 0 to asmore » much as 10 μg m -3, depending on the amount of SOA precursor gases in ambient air. Typically, more SOA was formed during nighttime than daytime, and more from OH than from O 3 oxidation. SOA yields of individual organic precursors under OFR conditions were measured by standard addition into ambient air, and confirmed to be consistent with published environmental chamber-derived SOA yields. Positive matrix factorization of organic aerosol (OA) after OH oxidation showed formation of typical oxidized OA factors and a loss of primary OA factors as OH aging increased. After OH oxidation in the OFR, the hygroscopicity of the OA increased with increasing elemental O : C up to O : C ~ 1.0, and then decreased as O : C increased further. Some possible reasons for this decrease are discussed. The measured SOA formation was compared to the amount predicted from the concentrations of measured ambient SOA precursors and their SOA yields. And while measured ambient precursors were sufficient to explain the amount of SOA formed from O 3, they could only explain 10–50 % of the SOA formed from OH. This is consistent with previous OFR studies which showed that typically unmeasured semivolatile and intermediate volatility gases (that tend to lack C = C bonds) are present in ambient air and can explain such additional SOA formation. To investigate the sources of the unmeasured SOA-forming gases

  14. Secondary organic aerosol formation from ambient air in an oxidation flow reactor in central Amazonia

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Palm, Brett B.; de Sá, Suzane S.; Day, Douglas A.

    Secondary organic aerosol (SOA) formation from ambient air was studied using an oxidation flow reactor (OFR) coupled to an aerosol mass spectrometer (AMS) during both the wet and dry seasons at the Observations and Modeling of the Green Ocean Amazon (GoAmazon2014/5) field campaign. Measurements were made at two sites downwind of the city of Manaus, Brazil. Ambient air was oxidized in the OFR using variable concentrations of either OH or O 3, over ranges from hours to days (O 3) or weeks (OH) of equivalent atmospheric aging. The amount of SOA formed in the OFR ranged from 0 to asmore » much as 10 μg m -3, depending on the amount of SOA precursor gases in ambient air. Typically, more SOA was formed during nighttime than daytime, and more from OH than from O 3 oxidation. SOA yields of individual organic precursors under OFR conditions were measured by standard addition into ambient air, and confirmed to be consistent with published environmental chamber-derived SOA yields. Positive matrix factorization of organic aerosol (OA) after OH oxidation showed formation of typical oxidized OA factors and a loss of primary OA factors as OH aging increased. After OH oxidation in the OFR, the hygroscopicity of the OA increased with increasing elemental O : C up to O : C ~ 1.0, and then decreased as O : C increased further. Some possible reasons for this decrease are discussed. The measured SOA formation was compared to the amount predicted from the concentrations of measured ambient SOA precursors and their SOA yields. And while measured ambient precursors were sufficient to explain the amount of SOA formed from O 3, they could only explain 10–50 % of the SOA formed from OH. This is consistent with previous OFR studies which showed that typically unmeasured semivolatile and intermediate volatility gases (that tend to lack C = C bonds) are present in ambient air and can explain such additional SOA formation. To investigate the sources of the unmeasured SOA-forming gases

  15. Secondary organic aerosol formation from ambient air in an oxidation flow reactor in central Amazonia

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Palm, Brett B.; de Sá, Suzane S.; Day, Douglas A.

    Secondary organic aerosol (SOA) formation from ambient air was studied using an oxidation flow reactor (OFR) coupled to an aerosol mass spectrometer (AMS) during both the wet and dry seasons at the Observations and Modeling of the Green Ocean Amazon (GoAmazon2014/5) field campaign. Measurements were made at two sites downwind of the city of Manaus, Brazil. Ambient air was oxidized in the OFR using variable concentrations of either OH or O 3, over ranges from hours to days (O 3) or weeks (OH) of equivalent atmospheric aging. The amount of SOA formed in the OFR ranged from 0 to asmore » much as 10 µg m −3, depending on the amount of SOA precursor gases in ambient air. Typically, more SOA was formed during nighttime than daytime, and more from OH than from O 3 oxidation. SOA yields of individual organic precursors under OFR conditions were measured by standard addition into ambient air and were confirmed to be consistent with published environmental chamber-derived SOA yields. Positive matrix factorization of organic aerosol (OA) after OH oxidation showed formation of typical oxidized OA factors and a loss of primary OA factors as OH aging increased. After OH oxidation in the OFR, the hygroscopicity of the OA increased with increasing elemental O : C up to O : C ∼ 1.0, and then decreased as O : C increased further. Possible reasons for this decrease are discussed. The measured SOA formation was compared to the amount predicted from the concentrations of measured ambient SOA precursors and their SOA yields. While measured ambient precursors were sufficient to explain the amount of SOA formed from O 3, they could only explain 10–50 % of the SOA formed from OH. This is consistent with previous OFR studies, which showed that typically unmeasured semivolatile and intermediate volatility gases (that tend to lack C = C bonds) are present in ambient air and can explain such additional SOA formation. To investigate the sources of the

  16. Secondary cell walls: biosynthesis, patterned deposition and transcriptional regulation.

    PubMed

    Zhong, Ruiqin; Ye, Zheng-Hua

    2015-02-01

    Secondary walls are mainly composed of cellulose, hemicelluloses (xylan and glucomannan) and lignin, and are deposited in some specialized cells, such as tracheary elements, fibers and other sclerenchymatous cells. Secondary walls provide strength to these cells, which lend mechanical support and protection to the plant body and, in the case of tracheary elements, enable them to function as conduits for transporting water. Formation of secondary walls is a complex process that requires the co-ordinated expression of secondary wall biosynthetic genes, biosynthesis and targeted secretion of secondary wall components, and patterned deposition and assembly of secondary walls. Here, we provide a comprehensive review of genes involved in secondary wall biosynthesis and deposition. Most of the genes involved in the biosynthesis of secondary wall components, including cellulose, xylan, glucomannan and lignin, have been identified and their co-ordinated activation has been shown to be mediated by a transcriptional network encompassing the secondary wall NAC and MYB master switches and their downstream transcription factors. It has been demonstrated that cortical microtubules and microtubule-associated proteins play important roles in the targeted secretion of cellulose synthase complexes, the oriented deposition of cellulose microfibrils and the patterned deposition of secondary walls. Further investigation of many secondary wall-associated genes with unknown functions will provide new insights into the mechanisms controlling the formation of secondary walls that constitute the bulk of plant biomass. © The Author 2014. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  17. Photoinduced, Copper-Catalyzed Carbon-Carbon Bond Formation with Alkyl Electrophiles: Cyanation of Unactivated Secondary Alkyl Chlorides at Room Temperature.

    PubMed

    Ratani, Tanvi S; Bachman, Shoshana; Fu, Gregory C; Peters, Jonas C

    2015-11-04

    We have recently reported that, in the presence of light and a copper catalyst, nitrogen nucleophiles such as carbazoles and primary amides undergo C-N coupling with alkyl halides under mild conditions. In the present study, we establish that photoinduced, copper-catalyzed alkylation can also be applied to C-C bond formation, specifically, that the cyanation of unactivated secondary alkyl chlorides can be achieved at room temperature to afford nitriles, an important class of target molecules. Thus, in the presence of an inexpensive copper catalyst (CuI; no ligand coadditive) and a readily available light source (UVC compact fluorescent light bulb), a wide array of alkyl halides undergo cyanation in good yield. Our initial mechanistic studies are consistent with the hypothesis that an excited state of [Cu(CN)2](-) may play a role, via single electron transfer, in this process. This investigation provides a rare example of a transition metal-catalyzed cyanation of an alkyl halide, as well as the first illustrations of photoinduced, copper-catalyzed alkylation with either a carbon nucleophile or a secondary alkyl chloride.

  18. Potential of select intermediate-volatility organic compounds and consumer products for secondary organic aerosol and ozone formation under relevant urban conditions

    NASA Astrophysics Data System (ADS)

    Li, Weihua; Li, Lijie; Chen, Chia-li; Kacarab, Mary; Peng, Weihan; Price, Derek; Xu, Jin; Cocker, David R.

    2018-04-01

    Emissions of certain low vapor pressure-volatile organic compounds (LVP-VOCs) are considered exempt to volatile organic compounds (VOC) regulations due to their low evaporation rates. However, these compounds may still play a role in ambient secondary organic aerosol (SOA) and ozone formation. The LVP-VOCs selected for this work are categorized as intermediate-volatility organic compounds (IVOCs) according to their vapor pressures and molecular formulas. In this study, the evaporation rates of 14 select IVOCs are investigated with half of them losing more than 95% of their mass in less than one month. Further, SOA and ozone formation are presented from 11 select IVOCs and 5 IVOC-containing generic consumer products under atmospherically relevant conditions using varying radical sources (NOx and/or H2O2) and a surrogate reactive organic gas (ROG) mixture. Benzyl alcohol (0.41), n-heptadecane (0.38), and diethylene glycol monobutyl ether (0.16) are determined to have SOA yields greater than 0.1 in the presence of NOx and a surrogate urban hydrocarbon mixture. IVOCs also influence ozone formation from the surrogate urban mixture by impacting radical levels and NOx availability. The addition of lab created generic consumer products has a weak influence on ozone formation from the surrogate mixture but strongly affects SOA formation. The overall SOA and ozone formation of the generic consumer products could not be explained solely by the results of the pure IVOC experiments.

  19. Translocation and gross deletion breakpoints in human inherited disease and cancer II: Potential involvement of repetitive sequence elements in secondary structure formation between DNA ends.

    PubMed

    Chuzhanova, Nadia; Abeysinghe, Shaun S; Krawczak, Michael; Cooper, David N

    2003-09-01

    Translocations and gross deletions are responsible for a significant proportion of both cancer and inherited disease. Although such gene rearrangements are nonuniformly distributed in the human genome, the underlying mutational mechanisms remain unclear. We have studied the potential involvement of various types of repetitive sequence elements in the formation of secondary structure intermediates between the single-stranded DNA ends that recombine during rearrangements. Complexity analysis was used to assess the potential of these ends to form secondary structures, the maximum decrease in complexity consequent to a gross rearrangement being used as an indicator of the type of repeat and the specific DNA ends involved. A total of 175 pairs of deletion/translocation breakpoint junction sequences available from the Gross Rearrangement Breakpoint Database [GRaBD; www.uwcm.ac.uk/uwcm/mg/grabd/grabd.html] were analyzed. Potential secondary structure was noted between the 5' flanking sequence of the first breakpoint and the 3' flanking sequence of the second breakpoint in 49% of rearrangements and between the 5' flanking sequence of the second breakpoint and the 3' flanking sequence of the first breakpoint in 36% of rearrangements. Inverted repeats, inversions of inverted repeats, and symmetric elements were found in association with gross rearrangements at approximately the same frequency. However, inverted repeats and inversions of inverted repeats accounted for the vast majority (83%) of deletions plus small insertions, symmetric elements for one-half of all antigen receptor-mediated translocations, while direct repeats appear only to be involved in mediating simple deletions. These findings extend our understanding of illegitimate recombination by highlighting the importance of secondary structure formation between single-stranded DNA ends at breakpoint junctions. Copyright 2003 Wiley-Liss, Inc.

  20. Secondary Inorganic Aerosols over an Urban Location in North-Western Himalayan Region: Seasonal Variation in Composition and Formation Process(es)

    NASA Astrophysics Data System (ADS)

    Kaushal, D.; Tandon, A.

    2017-12-01

    Oxidative photo-chemical transformation of precursor gases, mainly of anthropogenic origin, produces secondary aerosols. Secondary inorganic aerosols constitute a significant fraction of total aerosol load over urban locations especially high altitude in wet-temperate climatic set-up. Towns situated in North-Western Himalayan region (NWHR) with sizable population and attractive tourist destinations have been facing ever increasing problem of gaseous and particulate air pollution from exponential increase in vehicular traffic and other anthropogenic emissions. The present study has been planned to investigate the seasonal variations in atmospheric processes responsible for the formation of Secondary Inorganic Aerosols (SIA) and to estimate contribution of SIA to PM­10 load over an Urban location, Dharamshala, in Dhauladhar region of NWHR. Twenty four hourly PM10 aerosol samples were collected, on quartz micro fibre filters in Dharamshala (1350 amsl) on weekly basis for complete one year time-period (February 2015 - January 2016). These samples were analyzed for Water Soluble Inorganic Ions (WSII) using Ion-Chromatographic System. On annual basis, SO42- ions contributed maximum (52%) followed by NO3- (13%) and NH4+ (12%) to WSII. Based upon Principal Component Analysis (PCA), dominant sources contributing to PM10 associated WSII were identified as: Fossil-Fuel and Bio-mass burning, Vehicular (mainly diesel) emissions and gaseous emissions from the microbial degradation of dead bio-mass. Throughout the year, significantly high proportion of SO42- and considerable thermodynamic stability of (NH4)2SO2 at ambient temperatures, made it the major contributor to SIA over NH4NO3 and NH4Cl. On seasonal basis, maximum contribution of SIA to PM10 was observed in monsoon followed by the winter season. Low ambient temperature in winter season favoured formation of NH4NO3 with significant contribution to SIA. It could be concluded that observed variability in the composition and

  1. A Top-Down Pathway to Secondary Eyewall Formation in Simulated Tropical Cyclones

    NASA Astrophysics Data System (ADS)

    Tyner, Bryce; Zhu, Ping; Zhang, Jun A.; Gopalakrishnan, Sundararaman; Marks, Frank; Tallapragada, Vijay

    2018-01-01

    Idealized and real-case simulations conducted using the Hurricane Weather Research and Forecasting (HWRF) model demonstrate a "top-down" pathway to secondary eyewall formation (SEF) for tropical cyclones (TCs). For the real-case simulations of Hurricane Rita (2005) and Hurricane Edouard (2014), a comparison to observations reveals the timing and overall characteristics of the simulated SEF appear realistic. An important control of the top-down pathway to SEF is the amount and radial-height distribution of hydrometeors at outer radii. Examination into the simulated hydrometeor particle fall speed distribution reveals that the HWRF operational microphysics scheme is not producing the lightest hydrometeors, which are likely present in observed TCs and are most conducive to being advected from the primary eyewall to the outer rainband region of the TC. Triggering of SEF begins with the fallout of hydrometeors at the outer radii from the TC primary eyewall, where penetrative downdrafts resulting from evaporative cooling of precipitation promote the development of local convection. As the convection-induced radial convergence that is initially located in the midtroposphere extends downward into the boundary layer, it results in the eruption of high entropy air out of the boundary layer. This leads to the rapid development of rainband convection and subsequent SEF via a positive feedback among precipitation, convection, and boundary layer processes.

  2. Effects of NOx and SO2 on the secondary organic aerosol formation from photooxidation of α-pinene and limonene

    NASA Astrophysics Data System (ADS)

    Zhao, Defeng; Schmitt, Sebastian H.; Wang, Mingjin; Acir, Ismail-Hakki; Tillmann, Ralf; Tan, Zhaofeng; Novelli, Anna; Fuchs, Hendrik; Pullinen, Iida; Wegener, Robert; Rohrer, Franz; Wildt, Jürgen; Kiendler-Scharr, Astrid; Wahner, Andreas; Mentel, Thomas F.

    2018-02-01

    Anthropogenic emissions such as NOx and SO2 influence the biogenic secondary organic aerosol (SOA) formation, but detailed mechanisms and effects are still elusive. We studied the effects of NOx and SO2 on the SOA formation from the photooxidation of α-pinene and limonene at ambient relevant NOx and SO2 concentrations (NOx: < 1to 20 ppb, SO2: < 0.05 to 15 ppb). In these experiments, monoterpene oxidation was dominated by OH oxidation. We found that SO2 induced nucleation and enhanced SOA mass formation. NOx strongly suppressed not only new particle formation but also SOA mass yield. However, in the presence of SO2 which induced a high number concentration of particles after oxidation to H2SO4, the suppression of the mass yield of SOA by NOx was completely or partly compensated for. This indicates that the suppression of SOA yield by NOx was largely due to the suppressed new particle formation, leading to a lack of particle surface for the organics to condense on and thus a significant influence of vapor wall loss on SOA mass yield. By compensating for the suppressing effect on nucleation of NOx, SO2 also compensated for the suppressing effect on SOA yield. Aerosol mass spectrometer data show that increasing NOx enhanced nitrate formation. The majority of the nitrate was organic nitrate (57-77 %), even in low-NOx conditions (< ˜ 1 ppb). Organic nitrate contributed 7-26 % of total organics assuming a molecular weight of 200 g mol-1. SOA from α-pinene photooxidation at high NOx had a generally lower hydrogen to carbon ratio (H / C), compared to low NOx. The NOx dependence of the chemical composition can be attributed to the NOx dependence of the branching ratio of the RO2 loss reactions, leading to a lower fraction of organic hydroperoxides and higher fractions of organic nitrates at high NOx. While NOx suppressed new particle formation and SOA mass formation, SO2 can compensate for such effects, and the combining effect of SO2 and NOx may have an important

  3. Primary emissions and secondary organic aerosol formation from the exhaust of a flex-fuel (ethanol) vehicle

    NASA Astrophysics Data System (ADS)

    Suarez-Bertoa, R.; Zardini, A. A.; Platt, S. M.; Hellebust, S.; Pieber, S. M.; El Haddad, I.; Temime-Roussel, B.; Baltensperger, U.; Marchand, N.; Prévôt, A. S. H.; Astorga, C.

    2015-09-01

    Incentives to use biofuels may result in increasing vehicular emissions of compounds detrimental to air quality. Therefore, regulated and unregulated emissions from a Euro 5a flex-fuel vehicle, tested using E85 and E75 blends (gasoline containing 85% and 75% of ethanol (vol/vol), respectively), were investigated at 22 and -7 °C over the New European Driving Cycle, at the Vehicle Emission Laboratory at the European Commission Joint Research Centre Ispra, Italy. Vehicle exhaust was comprehensively analyzed at the tailpipe and in a dilution tunnel. A fraction of the exhaust was injected into a mobile smog chamber to study the photochemical aging of the mixture. We found that emissions from a flex-fuel vehicle, fueled by E85 and E75, led to secondary organic aerosol (SOA) formation, despite the low aromatic content of these fuel blends. Emissions of regulated and unregulated compounds, as well as emissions of black carbon (BC) and primary organic aerosol (POA) and SOA formation were higher at -7 °C. The flex-fuel unregulated emissions, mainly composed of ethanol and acetaldehyde, resulted in very high ozone formation potential and SOA, especially at low temperature (860 mg O3 km-1 and up to 38 mg C kg-1). After an OH exposure of 10 × 106 cm-3 h, SOA mass was, on average, 3 times larger than total primary particle mass emissions (BC + POA) with a high O:C ratio (up to 0.7 and 0.5 at 22 and -7 °C, respectively) typical of highly oxidized mixtures. Furthermore, high resolution organic mass spectra showed high 44/43 ratios (ratio of the ions m/z 44 and m/z 43) characteristic of low-volatility oxygenated organic aerosol. We also hypothesize that SOA formation from vehicular emissions could be due to oxidation products of ethanol and acetaldehyde, both short-chain oxygenated VOCs, e.g. methylglyoxal and acetic acid, and not only from aromatic compounds.

  4. UV light selectively coinduces supply pathways from primary metabolism and flavonoid secondary product formation in parsley

    PubMed Central

    Logemann, Elke; Tavernaro, Annette; Schulz, Wolfgang; Somssich, Imre E.; Hahlbrock, Klaus

    2000-01-01

    The UV light-induced synthesis of UV-protective flavonoids diverts substantial amounts of substrates from primary metabolism into secondary product formation and thus causes major perturbations of the cellular homeostasis. Results from this study show that the mRNAs encoding representative enzymes from various supply pathways are coinduced in UV-irradiated parsley cells (Petroselinum crispum) with two mRNAs of flavonoid glycoside biosynthesis, encoding phenylalanine ammonia-lyase and chalcone synthase. Strong induction was observed for mRNAs encoding glucose 6-phosphate dehydrogenase (carbohydrate metabolism, providing substrates for the shikimate pathway), 3-deoxyarabinoheptulosonate 7-phosphate synthase (shikimate pathway, yielding phenylalanine), and acyl-CoA oxidase (fatty acid degradation, yielding acetyl-CoA), and moderate induction for an mRNA encoding S-adenosyl-homocysteine hydrolase (activated methyl cycle, yielding S-adenosyl-methionine for B-ring methylation). Ten arbitrarily selected mRNAs representing various unrelated metabolic activities remained unaffected. Comparative analysis of acyl-CoA oxidase and chalcone synthase with respect to mRNA expression modes and gene promoter structure and function revealed close similarities. These results indicate a fine-tuned regulatory network integrating those functionally related pathways of primary and secondary metabolism that are specifically required for protective adaptation to UV irradiation. Although the response of parsley cells to UV light is considerably broader than previously assumed, it contrasts greatly with the extensive metabolic reprogramming observed previously in elicitor-treated or fungus-infected cells. PMID:10677554

  5. Secondary organic aerosol formation exceeds primary particulate matter emissions for light-duty gasoline vehicles

    NASA Astrophysics Data System (ADS)

    Gordon, T. D.; Presto, A. A.; May, A. A.; Nguyen, N. T.; Lipsky, E. M.; Donahue, N. M.; Gutierrez, A.; Zhang, M.; Maddox, C.; Rieger, P.; Chattopadhyay, S.; Maldonado, H.; Maricq, M. M.; Robinson, A. L.

    2014-05-01

    The effects of photochemical aging on emissions from 15 light-duty gasoline vehicles were investigated using a smog chamber to probe the critical link between the tailpipe and ambient atmosphere. The vehicles were recruited from the California in-use fleet; they represent a wide range of model years (1987 to 2011), vehicle types and emission control technologies. Each vehicle was tested on a chassis dynamometer using the unified cycle. Dilute emissions were sampled into a portable smog chamber and then photochemically aged under urban-like conditions. For every vehicle, substantial secondary organic aerosol (SOA) formation occurred during cold-start tests, with the emissions from some vehicles generating as much as 6 times the amount of SOA as primary particulate matter (PM) after 3 h of oxidation inside the chamber at typical atmospheric oxidant levels (and 5 times the amount of SOA as primary PM after 5 × 106 molecules cm-3 h of OH exposure). Therefore, the contribution of light-duty gasoline vehicle exhaust to ambient PM levels is likely dominated by secondary PM production (SOA and nitrate). Emissions from hot-start tests formed about a factor of 3-7 less SOA than cold-start tests. Therefore, catalyst warm-up appears to be an important factor in controlling SOA precursor emissions. The mass of SOA generated by photooxidizing exhaust from newer (LEV2) vehicles was a factor of 3 lower than that formed from exhaust emitted by older (pre-LEV) vehicles, despite much larger reductions (a factor of 11-15) in nonmethane organic gas emissions. These data suggest that a complex and nonlinear relationship exists between organic gas emissions and SOA formation, which is not surprising since SOA precursors are only one component of the exhaust. Except for the oldest (pre-LEV) vehicles, the SOA production could not be fully explained by the measured oxidation of speciated (traditional) SOA precursors. Over the timescale of these experiments, the mixture of organic vapors

  6. Secondary organic aerosol formation exceeds primary particulate matter emissions for light-duty gasoline vehicles

    NASA Astrophysics Data System (ADS)

    Gordon, T. D.; Presto, A. A.; May, A. A.; Nguyen, N. T.; Lipsky, E. M.; Donahue, N. M.; Gutierrez, A.; Zhang, M.; Maddox, C.; Rieger, P.; Chattopadhyay, S.; Maldonado, H.; Maricq, M. M.; Robinson, A. L.

    2013-09-01

    The effects of photochemical aging on emissions from 15 light-duty gasoline vehicles were investigated using a smog chamber to probe the critical link between the tailpipe and ambient atmosphere. The vehicles were recruited from the California in-use fleet; they represent a wide range of model years (1987 to 2011), vehicle types and emission control technologies. Each vehicle was tested on a chassis dynamometer using the unified cycle. Dilute emissions were sampled into a portable smog chamber and then photochemically aged under urban-like conditions. For every vehicle, substantial secondary organic aerosol (SOA) formation occurred during cold-start tests, with the emissions from some vehicles generating as much as 6 times the amount of SOA as primary particulate matter after three hours of oxidation inside the chamber at typical atmospheric oxidant levels. Therefore, the contribution of light duty gasoline vehicle exhaust to ambient PM levels is likely dominated by secondary PM production (SOA and nitrate). Emissions from hot-start tests formed about a factor of 3-7 less SOA than cold-start tests. Therefore, catalyst warm-up appears to be an important factor in controlling SOA precursor emissions. The mass of SOA generated by photo-oxidizing exhaust from newer (LEV1 and LEV2) vehicles was only modestly lower (38%) than that formed from exhaust emitted by older (pre-LEV) vehicles, despite much larger reductions in non-methane organic gas emissions. These data suggest that a complex and non-linear relationship exists between organic gas emissions and SOA formation, which is not surprising since SOA precursors are only one component of the exhaust. Except for the oldest (pre-LEV) vehicles, the SOA production could not be fully explained by the measured oxidation of speciated (traditional) SOA precursors. Over the time scale of these experiments, the mixture of organic vapors emitted by newer vehicles appear to be more efficient (higher yielding) in producing SOA than

  7. Hydraulic and Mechanical Effects from Gas Hydrate Conversion and Secondary Gas Hydrate Formation during Injection of CO2 into CH4-Hydrate-Bearing Sediments

    NASA Astrophysics Data System (ADS)

    Bigalke, N.; Deusner, C.; Kossel, E.; Schicks, J. M.; Spangenberg, E.; Priegnitz, M.; Heeschen, K. U.; Abendroth, S.; Thaler, J.; Haeckel, M.

    2014-12-01

    The injection of CO2 into CH4-hydrate-bearing sediments has the potential to drive natural gas production and simultaneously sequester CO2 by hydrate conversion. The process aims at maintaining the in situ hydrate saturation and structure and causing limited impact on soil hydraulic properties and geomechanical stability. However, to increase hydrate conversion yields and rates it must potentially be assisted by thermal stimulation or depressurization. Further, secondary formation of CO2-rich hydrates from pore water and injected CO2 enhances hydrate conversion and CH4 production yields [1]. Technical stimulation and secondary hydrate formation add significant complexity to the bulk conversion process resulting in spatial and temporal effects on hydraulic and geomechanical properties that cannot be predicted by current reservoir simulation codes. In a combined experimental and numerical approach, it is our objective to elucidate both hydraulic and mechanical effects of CO2 injection and CH4-CO2-hydrate conversion in CH4-hydrate bearing soils. For the experimental approach we used various high-pressure flow-through systems equipped with different online and in situ monitoring tools (e.g. Raman microscopy, MRI and ERT). One particular focus was the design of triaxial cell experimental systems, which enable us to study sample behavior even during large deformations and particle flow. We present results from various flow-through high-pressure experimental studies on different scales, which indicate that hydraulic and geomechanical properties of hydrate-bearing sediments are drastically altered during and after injection of CO2. We discuss the results in light of the competing processes of hydrate dissociation, hydrate conversion and secondary hydrate formation. Our results will also contribute to the understanding of effects of temperature and pressure changes leading to dissociation of gas hydrates in ocean and permafrost systems. [1] Deusner C, Bigalke N, Kossel E

  8. Modeling the formation and properties of traditional and non-traditional secondary organic aerosol: problem formulation and application to aircraft exhaust

    NASA Astrophysics Data System (ADS)

    Jathar, S. H.; Miracolo, M. A.; Presto, A. A.; Adams, P. J.; Robinson, A. L.

    2012-04-01

    We present a methodology to model secondary organic aerosol (SOA) formation from the photo-oxidation of low-volatility organics (semi-volatile and intermediate volatility organic compounds). The model is parameterized and tested using SOA data collected during two field campaigns that characterized the atmospheric evolution of dilute gas-turbine engine emissions using a smog chamber. Photo-oxidation formed a significant amount of SOA, much of which cannot be explained based on the emissions of traditional, speciated precursors; we refer to this as non-traditional SOA (NT-SOA). The NT-SOA can be explained by emissions of low-volatility organic vapors measured using sorbents. Since these vapors could not be speciated, we employ a volatility-based approach to model NT-SOA formation. We show that the method proposed by Robinson et al. (2007) is unable to explain the timing of NT-SOA formation because it assumes a very modest reduction in volatility of the precursors with every oxidation reaction. In contrast, a Hybrid method, similar to models of traditional SOA formation, assumes a larger reduction in volatility with each oxidation step and results in a better reproduction of NT-SOA formation. The NT-SOA yields estimated for the low-volatility organic vapor emissions are similar to literature data for large n-alkanes and other low-volatility organics. The yields vary with fuel composition (JP8 versus Fischer-Tropsch) and engine load (idle versus non-idle). These differences are consistent with the expected contribution of high (aromatics and n-alkanes) and low (branched alkanes and oxygenated species) SOA forming species to the exhaust.

  9. Photosensitized Formation of Secondary Organic Aerosols above the Air/Water Interface

    PubMed Central

    2016-01-01

    In this study, we evaluated photosensitized chemistry at the air–sea interface as a source of secondary organic aerosols (SOA). Our results show that, in addition to biogenic emissions, abiotic processes could also be important in the marine boundary layer. Photosensitized production of marine secondary organic aerosol was studied in a custom-built multiphase atmospheric simulation chamber. The experimental chamber contained water, humic acid (1–10 mg L–1) as a proxy for dissolved organic matter, and nonanoic acid (0.1–10 mM), a fatty acid proxy which formed an organic film at the air–water interface. Dark secondary reaction with ozone after illumination resulted in SOA particle concentrations in excess of 1000 cm–3, illustrating the production of unsaturated compounds by chemical reactions at the air–water interface. SOA numbers via photosensitization alone and in the absence of ozone did not exceed background levels. From these results, we derived a dependence of SOA numbers on nonanoic acid surface coverage and dissolved organic matter concentration. We present a discussion on the potential role of the air–sea interface in the production of atmospheric organic aerosol from photosensitized origins. PMID:27434860

  10. Effects of Relative Humidity on Ozone and Secondary Organic Aerosol Formation from the Photooxidation of Benzene and Ethylbenzene

    NASA Astrophysics Data System (ADS)

    Jia, L.; Xu, Y.

    2012-12-01

    The formation of ozone and secondary organic aerosol from benzene-NOx and ethylbenzene-NOx irradiations was investigated under different levels of relative humidity (RH) in a smog chamber. The results show that the increase in RH can greatly reduce the maximum O3 by the transformation of -NO2 and -ONO2-containing products into the particle phase. In benzene irradiations, the SOA number concentration increases over 26 times as RH rises from <5% to 80%, and the intensity of the bands of -OH, -C=O and C-OH from SOA samples also greatly increases with RH. In ethylbenzene irradiations, ethylglyoxal favors the formation of monohydrate, which limits the RH effects. During evaporating processes, the lost substances have similar structures for both benzene and ethylbenzene. This demonstrates that ethyl-containing substances are very stable and difficult to evaporate. For benzene some of glyoxal hydrates are left to form C-O-C and C=O-containing species like hemiacetal and acetal after evaporation, whereas for ethylbenzene, glyoxal favors cross reactions with ethylglyoxal during the evaporating process. It is concluded that the increase in RH can irreversibly enhance the yields of SOA from both benzene and ethylbenzene.

  11. The effect of gas-phase polycyclic aromatic hydrocarbons on the formation and properties of biogenic secondary organic aerosol particles

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zelenyuk, Alla; Imre, Dan G.; Wilson, Jacqueline

    2017-01-01

    When secondary organic aerosol (SOA) particles are formed by ozonolysis in the presence of gas-phase polycyclic aromatic hydrocarbons (PAHs), their formation and properties are significantly different from SOA particles formed without PAHs. For all SOA precursors and all PAHs, discussed in this study, the presence of the gas-phase PAHs during SOA formation significantly affects particle mass loadings, composition, growth, evaporation kinetics, and viscosity. SOA particles formed in the presence of PAHs have, as part of their compositions, trapped unreacted PAHs and products of heterogeneous reactions between PAHs and ozone. Compared to ‘pure’ SOA particles, these particles exhibit slower evaporation kinetics,more » have higher fractions of non-volatile components, like oligomers, and higher viscosities, assuring their longer atmospheric lifetimes. In turn, the increased viscosity and decreased volatility provide a shield that protects PAHs from chemical degradation and evaporation, allowing for the long-range transport of these toxic pollutants. The magnitude of the effect of PAHs on SOA formation is surprisingly large. The presence of PAHs during SOA formation increases mass loadings by factors of two to five, and particle number concentrations, in some cases, by more than a factor of 100. Increases in SOA mass, particle number concentrations, and lifetime have important implications to many atmospheric processes related to climate, weather, visibility, and human health, all of which relate to the interactions between biogenic SOA and anthropogenic PAHs. The synergistic relationship between SOA and PAHs presented here are clearly complex and call for future research to elucidate further the underlying processes and their exact atmospheric implications.« less

  12. EVALUATION OF SECONDARY ORGANIC AEROSOL FORMATION IN WINTER. (R823514)

    EPA Science Inventory

    Three different methods are used to predict secondary organic aerosol (SOA)
    concentrations in the San Joaquin Valley of California during the winter of 1995-1996 [Integrated
    Monitoring Study, (IMS95)]. The first of these methods estimates SOA by using elemental carbon as

  13. Secondary osteoporosis.

    PubMed

    Gennari, C; Martini, G; Nuti, R

    1998-06-01

    Generalized osteoporosis currently represents a heterogeneous group of conditions with many different causes and pathogenetic mechanisms, that often are variably associated. The term "secondary" is applied to all patients with osteoporosis in whom the identifiable causal factors are other than menopause and aging. In this heterogeneous group of conditions, produced by many different pathogenetic mechanisms, a negative bone balance may be variably associated with low, normal or increased bone remodeling states. A consistent group of secondary osteoporosis is related to endocrinological or iatrogenic causes. Exogenous hypercortisolism may be considered an important risk factor for secondary osteoporosis in the community, and probably glucocorticoid-induced osteoporosis is the most common type of secondary osteoporosis. Supraphysiological doses of corticosteroids cause two abnormalities in bone metabolism: a relative increase in bone resorption, and a relative reduction in bone formation. Bone loss, mostly of trabecular bone, with its resultant fractures is the most incapacitating consequence of osteoporosis. The estimated incidence of fractures in patients prescribed corticosteroid is 30% to 50%. Osteoporosis is considered one of the potentially serious side effects of heparin therapy. The occurrence of heparin-induced osteoporosis appeared to be strictly related to the length of treatment (over 4-5 months), and the dosage (15,000 U or more daily), but the pathogenesis is poorly understood. It has been suggested that heparin could cause an increase in bone resorption by increasing the number of differentiated osteoclasts, and by enhancing the activity of individual osteoclasts. Hyperthyroidism is frequently associated with loss of trabecular and cortical bone; the enhanced bone turnover that develops in thyrotoxicosis is characterized by an increase in the number of osteoclasts and resorption sites, and an increase in the ratio of resorptive to formative bone

  14. Association of fungal secondary metabolism and sclerotial biology

    PubMed Central

    Calvo, Ana M.; Cary, Jeffrey W.

    2015-01-01

    Fungal secondary metabolism and morphological development have been shown to be intimately associated at the genetic level. Much of the literature has focused on the co-regulation of secondary metabolite production (e.g., sterigmatocystin and aflatoxin in Aspergillus nidulans and Aspergillus flavus, respectively) with conidiation or formation of sexual fruiting bodies. However, many of these genetic links also control sclerotial production. Sclerotia are resistant structures produced by a number of fungal genera. They also represent the principal source of primary inoculum for some phytopathogenic fungi. In nature, higher plants often concentrate secondary metabolites in reproductive structures as a means of defense against herbivores and insects. By analogy, fungi also sequester a number of secondary metabolites in sclerotia that act as a chemical defense system against fungivorous predators. These include antiinsectant compounds such as tetramic acids, indole diterpenoids, pyridones, and diketopiperazines. This chapter will focus on the molecular mechanisms governing production of secondary metabolites and the role they play in sclerotial development and fungal ecology, with particular emphasis on Aspergillus species. The global regulatory proteins VeA and LaeA, components of the velvet nuclear protein complex, serve as virulence factors and control both development and secondary metabolite production in many Aspergillus species. We will discuss a number of VeA- and LaeA-regulated secondary metabolic gene clusters in A. flavus that are postulated to be involved in sclerotial morphogenesis and chemical defense. The presence of multiple regulatory factors that control secondary metabolism and sclerotial formation suggests that fungi have evolved these complex regulatory mechanisms as a means to rapidly adapt chemical responses to protect sclerotia from predators, competitors and other environmental stressors. PMID:25762985

  15. Secondary organic aerosol formation from low-NO(x) photooxidation of dodecane: evolution of multigeneration gas-phase chemistry and aerosol composition.

    PubMed

    Yee, Lindsay D; Craven, Jill S; Loza, Christine L; Schilling, Katherine A; Ng, Nga Lee; Canagaratna, Manjula R; Ziemann, Paul J; Flagan, Richard C; Seinfeld, John H

    2012-06-21

    The extended photooxidation of and secondary organic aerosol (SOA) formation from dodecane (C(12)H(26)) under low-NO(x) conditions, such that RO(2) + HO(2) chemistry dominates the fate of the peroxy radicals, is studied in the Caltech Environmental Chamber based on simultaneous gas and particle-phase measurements. A mechanism simulation indicates that greater than 67% of the initial carbon ends up as fourth and higher generation products after 10 h of reaction, and simulated trends for seven species are supported by gas-phase measurements. A characteristic set of hydroperoxide gas-phase products are formed under these low-NO(x) conditions. Production of semivolatile hydroperoxide species within three generations of chemistry is consistent with observed initial aerosol growth. Continued gas-phase oxidation of these semivolatile species produces multifunctional low volatility compounds. This study elucidates the complex evolution of the gas-phase photooxidation chemistry and subsequent SOA formation through a novel approach comparing molecular level information from a chemical ionization mass spectrometer (CIMS) and high m/z ion fragments from an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS). Combination of these techniques reveals that particle-phase chemistry leading to peroxyhemiacetal formation is the likely mechanism by which these species are incorporated in the particle phase. The current findings are relevant toward understanding atmospheric SOA formation and aging from the "unresolved complex mixture," comprising, in part, long-chain alkanes.

  16. Secondary organic aerosol formation from photochemical aging of light-duty gasoline vehicle exhausts in a smog chamber

    NASA Astrophysics Data System (ADS)

    Liu, T.; Wang, X.; Deng, W.; Hu, Q.; Ding, X.; Zhang, Y.; He, Q.; Zhang, Z.; Lü, S.; Bi, X.; Chen, J.; Yu, J.

    2015-04-01

    In China, fast increase in passenger vehicles has procured the growing concern about vehicle exhausts as an important source of anthropogenic secondary organic aerosols (SOA) in megacities hard-hit by haze. However, there are still no chamber simulation studies in China on SOA formation from vehicle exhausts. In this study, the SOA formation of emissions from two idling light-duty gasoline vehicles (LDGVs) (Euro 1 and Euro 4) in China was investigated in a 30 m3 smog chamber. Five photo-oxidation experiments were carried out at 25 °C with the relative humidity around 50%. After aging at an OH exposure of 5 × 106 molecules cm-3 h, the formed SOA was 12-259 times as high as primary OA (POA). The SOA production factors (PF) were 0.001-0.044 g kg-1 fuel, comparable with those from the previous studies at the quite similar OH exposure. This quite lower OH exposure than that in typical atmospheric condition might however lead to the underestimation of the SOA formation potential from LDGVs. Effective SOA yield data in this study were well fit by a one-product gas-particle partitioning model and quite lower than those of a previous study investigating SOA formation form three idling passenger vehicles (Euro 2-Euro 4). Traditional single-ring aromatic precursors and naphthalene could explain 51-90% of the formed SOA. Unspeciated species such as branched and cyclic alkanes might be the possible precursors for the unexplained SOA. A high-resolution time-of-flight aerosol mass spectrometer was used to characterize the chemical composition of SOA. The relationship between f43 (ratio of m/z 43, mostly C2H3O+, to the total signal in mass spectrum) and f44 (mostly CO2+) of the gasoline vehicle exhaust SOA is similar to the ambient semi-volatile oxygenated organic aerosol (SV-OOA). We plot the O : C and H : C molar ratios of SOA in a Van Krevelen diagram. The slopes of ΔH : C/ΔO : C ranged from -0.59 to -0.36, suggesting that the oxidation chemistry in these experiments was a

  17. Hemophilia A Pseudoaneurysm in a Patient with High Responding Inhibitors Complicating Total Knee Arthroplasty: Embolization: A Cost-Reducing Alternative to Medical Therapy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kickuth, Ralph, E-mail: ralph.kickuth@insel.ch; Anderson, Suzanne; Peter-Salonen, Kristiina

    2006-12-15

    Joint hemorrhages are very common in patients with severe hemophilia. Inhibitors in patients with hemophilia are allo-antibodies that neutralize the activity of the clotting factor. After total knee replacement, rare intra-articular bleeding complications might occur that do not respond to clotting factor replacement. We report a 40-year-old male with severe hemophilia A and high responding inhibitors presenting with recurrent knee joint hemorrhage after bilateral knee prosthetic surgery despite adequate clotting factor treatment. There were two episodes of marked postoperative hemarthrosis requiring extensive use of subsititution therapy. Eleven days postoperatively, there was further hemorrhage into the right knee. Digital subtraction angiographymore » diagnosed a complicating pseudoaneurysm of the inferior lateral geniculate artery and embolization was successfully performed. Because clotting factor replacement therapy has proved to be excessively expensive and prolonged, especially in patients with inhibitors, we recommend the use of cost-effective early angiographic embolization.« less

  18. Primary particulate emissions and secondary organic aerosol (SOA) formation from idling diesel vehicle exhaust in China.

    PubMed

    Deng, Wei; Hu, Qihou; Liu, Tengyu; Wang, Xinming; Zhang, Yanli; Song, Wei; Sun, Yele; Bi, Xinhui; Yu, Jianzhen; Yang, Weiqiang; Huang, Xinyu; Zhang, Zhou; Huang, Zhonghui; He, Quanfu; Mellouki, Abdelwahid; George, Christian

    2017-09-01

    In China diesel vehicles dominate the primary emission of particulate matters from on-road vehicles, and they might also contribute substantially to the formation of secondary organic aerosols (SOA). In this study tailpipe exhaust of three typical in-use diesel vehicles under warm idling conditions was introduced directly into an indoor smog chamber with a 30m 3 Teflon reactor to characterize primary emissions and SOA formation during photo-oxidation. The emission factors of primary organic aerosol (POA) and black carbon (BC) for the three types of Chinese diesel vehicles ranged 0.18-0.91 and 0.15-0.51gkg-fuel -1 , respectively; and the SOA production factors ranged 0.50-1.8gkg-fuel -1 and SOA/POA ratios ranged 0.7-3.7 with an average of 2.2. The fuel-based POA emission factors and SOA production factors from this study for idling diesel vehicle exhaust were 1-3 orders of magnitude higher than those reported in previous studies for idling gasoline vehicle exhaust. The emission factors for total particle numbers were 0.65-4.0×10 15 particleskg-fuel -1 , and particles with diameters less than 50nm dominated in total particle numbers. Traditional C 2 -C 12 precursor non-methane hydrocarbons (NMHCs) could only explain less than 3% of the SOA formed during aging and contribution from other precursors including intermediate volatile organic compounds (IVOC) needs further investigation. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Fostering Spiritual Formation of Millennials in Christian Schools

    ERIC Educational Resources Information Center

    Horan, Anne Puidk

    2017-01-01

    Christian education seeks to foster millennials' spiritual formation to equip them for future challenges and to benefit society. Using nonexperimental mixed methods, 504 secondary educators revealed what spiritual formation programs their schools implement and their perceptions about millennial spiritual formation. Descriptive analysis showed that…

  20. Secondary organic aerosol formation from semi- and intermediate-volatility organic compounds and glyoxal: Relevance of O/C as a tracer for aqueous multiphase chemistry

    NASA Astrophysics Data System (ADS)

    Waxman, Eleanor M.; Dzepina, Katja; Ervens, Barbara; Lee-Taylor, Julia; Aumont, Bernard; Jimenez, Jose L.; Madronich, Sasha; Volkamer, Rainer

    2013-03-01

    The role of aqueous multiphase chemistry in the formation of secondary organic aerosol (SOA) remains difficult to quantify. We investigate it here by testing the rapid formation of moderate oxygen-to-carbon (O/C) SOA during a case study in Mexico City. A novel laboratory-based glyoxal-SOA mechanism is applied to the field data, and explains why less gas-phase glyoxal mass is observed than predicted. Furthermore, we compare an explicit gas-phase chemical mechanism for SOA formation from semi- and intermediate-volatility organic compounds (S/IVOCs) with empirical parameterizations of S/IVOC aging. The mechanism representing our current understanding of chemical kinetics of S/IVOC oxidation combined with traditional SOA sources and mixing of background SOA underestimates the observed O/C by a factor of two at noon. Inclusion of glyoxal-SOA with O/C of 1.5 brings O/C predictions within measurement uncertainty, suggesting that field observations can be reconciled on reasonable time scales using laboratory-based empirical relationships for aqueous chemistry.

  1. Characterization of Organic Nitrate Formation in Limonene Secondary Organic Aerosol using High-Resolution Chemical Ionization Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Faxon, Cameron; Hammes, Julia; Peng, Jianfei; Hallquist, Mattias; Pathak, Ravi

    2016-04-01

    Previous work has shown that organic nitrates (RONO2) are prevalent in the boundary layer, and can contribute significantly to secondary organic aerosol formation. Monoterpenes, including limonene, have been shown to be precursors for the formation of these organic nitrates. Limonene has two double bonds, either of which may be oxidized by NO3 or O3. This leads to the generation of products that can subsequently condense or partition into the particle phase, producing secondary organic aerosol. In order to further elucidate the particle and gas phase product distribution of organic nitrates forming from the reactions of limonene and the nitrate radical (NO3), a series of experiments were performed in the Gothenburg Flow Reactor for Oxidation Studies at Low Temperatures (G-FROST), described by previous work. N2O5 was used as the source for NO3 and NO2, and a characterized diffusion source was used to introduce limonene into the flow reactor. All experiments were conducted in the absence of light, and the concentration of limonene was increased step-wise throughout each experiment to modify the ratio of N2O5to limonene. The experiments were conducted such that both limonene- and N2O5-limited regimes were present. Gas and particle phase products were measured using an iodide High-Resolution Time-of-Flight Mass Spectrometer (HR-ToF-CIMS) coupled to a Filter Inlet for Gases and AEROsols (FIGAERO, and particle size and SOA mass concentrations were derived using a Scanning Mobility Particle Sizer (SMPS). CIMS measurement techniques have previously been employed for the measurement of organic nitrate products of such compounds using multiple reagent ions. The use of this instrumentation allowed for the identification of chemical formulas for gas and particle phase species. The findings from the experiments will be presented in terms of the relative gas-particle partitioning of major products and the effects of N2O5/limonene ratios on product distributions. Additionally, a

  2. The SOA formation model combined with semiempirical quantum chemistry for predicting UV-Vis absorption of secondary organic aerosols.

    PubMed

    Zhong, Min; Jang, Myoseon; Oliferenko, Alexander; Pillai, Girinath G; Katritzky, Alan R

    2012-07-07

    A new model for predicting the UV-visible absorption spectra of secondary organic aerosols (SOA) has been developed. The model consists of two primary parts: a SOA formation model and a semiempirical quantum chemistry method. The mass of SOA is predicted using the PHRCSOA (Partitioning Heterogeneous Reaction Consortium Secondary Organic Aerosol) model developed by Cao and Jang [Environ. Sci. Technol., 2010, 44, 727]. The chemical composition is estimated using a combination of the kinetic model (MCM) and the PHRCSOA model. The absorption spectrum is obtained by taking the sum of the spectrum of each SOA product calculated using a semiempirical NDDO (Neglect of Diatomic Differential Overlap)-based method. SOA was generated from the photochemical reaction of toluene or α-pinene at different NO(x) levels (low NO(x): 24-26 ppm, middle NO(x): 49 ppb, high NO(x): 104-105 ppb) using a 2 m(3) indoor Teflon film chamber. The model simulation reasonably agrees with the measured absorption spectra of α-pinene SOA but underestimates toluene SOA under high and middle NO(x) conditions. The absorption spectrum of toluene SOA is moderately enhanced with increasing NO(x) concentrations, while that of α-pinene SOA is not affected. Both measured and calculated UV-visible spectra show that the light absorption of toluene SOA is much stronger than that of α-pinene SOA.

  3. Spontaneous Arterial Dissection.

    PubMed

    Brandt, Tobias; Caplan, Louis

    2001-09-01

    There is no controlled study for the best treatment or management of cervico-cerebral artery dissection (CAD). Rationale initial empiric treatment in acute CAD to prevent secondary embolism is partial thromboplastin time (PTT)-guided anticoagulation by intravenous heparin followed by anticoagulation with warfarin. Carotid surgery for treatment of CAD is not recommended anymore with the possible exception of persisting severe stenosis of the proximal internal carotid artery (ICA). There could be use of carotid angioplasty by balloon dilatation and stenting in selected cases of severe cerebral hemodynamic impairment by bilateral CAD. Duration of secondary prophylaxis by anticoagulation is best guided by Doppler sonography follow-up, and should be continued until normalization of blood flow or until at least 1 year after the vessel is occluded. There is no evidence that pseudoaneurysms increase the risk for embolic complication, and there is no evidence for surgery or continuation of anticoagulation in patients with pseudoaneurysms. Caution should be recommended for exercises that involve excessive head movements (eg, bungee jumping, trampoline jumping, and chiropractic maneuvers). The patient should be informed that recurrent rate is low in nonfamilial cases. Doppler sonography is a low-cost and high-sensitivity method for patients at risk.

  4. Secondary Organic Aerosol Formation from 2-Methyl-3-Buten-2-ol Photooxidation: Evidence of Acid-Catalyzed Reactive Uptake of Epoxides

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhang, Haofei; Zhang, Zhenfa; Cui, Tianqu

    2014-04-08

    Secondary organic aerosol (SOA) formation from 2-methyl-3-buten-2-ol (MBO) photooxidation has recently been observed in both field and laboratory studies. Similar to isoprene, MBO-derived SOA increases with elevated aerosol acidity in the absence of nitric oxide; therefore, an epoxide intermediate, (3,3-dimethyloxiran-2-yl)methanol (MBO epoxide) was synthesized and tentatively proposed here to explain this enhancement. In the present study, the potential of the synthetic MBO epoxide to form SOA via reactive uptake was systematically examined. SOA was observed only in the presence of acidic aerosols. Major SOA constituents, 2,3-dihydroxyisopentanol (DHIP) and MBO-derived organosulfate isomers, were chemically characterized in both laboratory-generated SOA and inmore » ambient fine aerosols collected from the BEACHON-RoMBAS field campaign during summer 2011, where MBO emissions are substantial. Our results support epoxides as potential products of MBO photooxidation leading to formation of atmospheric SOA and suggest that reactive uptake of epoxides may generally explain acid enhancement of SOA observed from other biogenic hydrocarbons.« less

  5. Pairwise amino acid secondary structural propensities

    NASA Astrophysics Data System (ADS)

    Chemmama, Ilan E.; Chapagain, Prem P.; Gerstman, Bernard S.

    2015-04-01

    We investigate the propensities for amino acids to form a specific secondary structure when they are paired with other amino acids. Our investigations use molecular dynamics (MD) computer simulations, and we compare the results to those from the Protein Data Bank (PDB). Proper comparison requires weighting of the MD results in a manner consistent with the relative frequency of appearance in the PDB of each possible pair of amino acids. We find that the propensity for an amino acid to assume a secondary structure varies dramatically depending on the amino acid that is before or after it in the primary sequence. This cooperative effect means that when selecting amino acids to facilitate the formation of a secondary structure in peptide engineering experiments, the adjacent amino acids must be considered. We also examine the preference for a secondary structure in bacterial proteins and compare the results to those of human proteins.

  6. Foreign body granuloma formation secondary to silicone injection.

    PubMed

    Schwartzfarb, Elissa M; Hametti, Juan Martin; Romanelli, Paolo; Ricotti, Carlos

    2008-07-15

    Injectable silicone has been used extensively over the last 40 years for soft tissue augmentation. Although considered biologically inert, this material has been implicated in a variety of adverse reactions including granulomas, disfiguring nodules, and lymphedema, sometimes with latent periods of decades. Often these complications are a result of the use of industrial grade products injected by unlicensed or unskilled practitioners. Here we report a case of foreign body granuloma in the thigh secondary to silicone injection in the buttocks. Initially the patient did not disclose a cosmetic contouring procedure administered by a nonprofessional nine months earlier, making diagnosis difficult. We remind clinicians to include foreign body granulomas in the differential diagnosis of apparent cellulitis and to question patients about the use of injectable fillers.

  7. Parental Involvement in the Secondary Schools in Bangladesh: Challenges and a Way Forward

    ERIC Educational Resources Information Center

    Kabir, Ariful Haq; Akter, Farjana

    2014-01-01

    Parental involvement with secondary schools is a relatively new concept in the Bangladeshi education perspective. The formation of School Management Committee (SMC) and various programs carried out by the secondary schools have created opportunities for parents as community members to be involved in secondary schools in Bangladesh. This article…

  8. Role of DNA secondary structures in fragile site breakage along human chromosome 10

    PubMed Central

    Dillon, Laura W.; Pierce, Levi C. T.; Ng, Maggie C. Y.; Wang, Yuh-Hwa

    2013-01-01

    The formation of alternative DNA secondary structures can result in DNA breakage leading to cancer and other diseases. Chromosomal fragile sites, which are regions of the genome that exhibit chromosomal breakage under conditions of mild replication stress, are predicted to form stable DNA secondary structures. DNA breakage at fragile sites is associated with regions that are deleted, amplified or rearranged in cancer. Despite the correlation, unbiased examination of the ability to form secondary structures has not been evaluated in fragile sites. Here, using the Mfold program, we predict potential DNA secondary structure formation on the human chromosome 10 sequence, and utilize this analysis to compare fragile and non-fragile DNA. We found that aphidicolin (APH)-induced common fragile sites contain more sequence segments with potential high secondary structure-forming ability, and these segments clustered more densely than those in non-fragile DNA. Additionally, using a threshold of secondary structure-forming ability, we refined legitimate fragile sites within the cytogenetically defined boundaries, and identified potential fragile regions within non-fragile DNA. In vitro detection of alternative DNA structure formation and a DNA breakage cell assay were used to validate the computational predictions. Many of the regions identified by our analysis coincide with genes mutated in various diseases and regions of copy number alteration in cancer. This study supports the role of DNA secondary structures in common fragile site instability, provides a systematic method for their identification and suggests a mechanism by which DNA secondary structures can lead to human disease. PMID:23297364

  9. Molecular control of wood formation in trees.

    PubMed

    Ye, Zheng-Hua; Zhong, Ruiqin

    2015-07-01

    Wood (also termed secondary xylem) is the most abundant biomass produced by plants, and is one of the most important sinks for atmospheric carbon dioxide. The development of wood begins with the differentiation of the lateral meristem, vascular cambium, into secondary xylem mother cells followed by cell expansion, secondary wall deposition, programmed cell death, and finally heartwood formation. Significant progress has been made in the past decade in uncovering the molecular players involved in various developmental stages of wood formation in tree species. Hormonal signalling has been shown to play critical roles in vascular cambium cell proliferation and a peptide-receptor-transcription factor regulatory mechanism similar to that controlling the activity of apical meristems is proposed to be involved in the maintenance of vascular cambium activity. It has been demonstrated that the differentiation of vascular cambium into xylem mother cells is regulated by plant hormones and HD-ZIP III transcription factors, and the coordinated activation of secondary wall biosynthesis genes during wood formation is mediated by a transcription network encompassing secondary wall NAC and MYB master switches and their downstream transcription factors. Most genes encoding the biosynthesis enzymes for wood components (cellulose, xylan, glucomannan, and lignin) have been identified in poplar and a number of them have been functionally characterized. With the availability of genome sequences of tree species from both gymnosperms and angiosperms, and the identification of a suite of wood-associated genes, it is expected that our understanding of the molecular control of wood formation in trees will be greatly accelerated. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  10. On the coupling of convective updrafts prior to secondary eyewall formation in Hurricane Katrina (2005)

    NASA Astrophysics Data System (ADS)

    Garcia-Rivera, Jose M.; Lin, Yuh-Lang

    2017-09-01

    Hurricane Katrina (2005) was simulated by the Advanced Research Weather Research and Forecasting model to understand the mechanism of a secondary eyewall formation (SEF) prior to its last landfall. The storm underwent a series of structural changes that were deemed necessary for the concentric cycle to begin, which included (1) increased rainband activity outside the primary eyewall in the hours before, mostly related to an intensifying main feeder band, (2) close to initiation of the SEF, an updraft (explained by a pre-existing hypothesis) emerged outside the primary eyewall near the top of the boundary layer (BL), (3) this updraft then intensified and extended both upward and outward, while the storm intensified and approached SEF, (4) eventually, the updraft coupled with the upward motion associated with rainband-related convection near the SEF radius, and (5) once the alignment occurred, the deep updraft quickly organized to support deep convection that led to SEF within hours of initiation. The coupling of updrafts emanating from the BL with the environmental upward motion associated with the pre-existing rainband activity is proposed to be the key mechanism for the SEF initiation in this case.

  11. Followership among UK Secondary School Teachers

    ERIC Educational Resources Information Center

    Francis, Andrew

    2014-01-01

    This paper reports the preliminary findings of an exploratory study which investigates the followership of longstanding, classroom-based school teachers working in the UK secondary education sector. Using Gronn's (1999) educational leadership formation model as a frame of reference, the study employs a multiple case study methodology with data…

  12. Diurnally resolved particulate and VOC measurements at a rural site: indication of significant biogenic secondary organic aerosol formation

    NASA Astrophysics Data System (ADS)

    Sjostedt, S. J.; Slowik, J. G.; Brook, J. R.; Chang, R. Y.-W.; Mihele, C.; Stroud, C. A.; Vlasenko, A.; Abbatt, J. P. D.

    2010-11-01

    We report simultaneous measurements of volatile organic compound (VOC) mixing ratios including C6 to C8 aromatics, isoprene, monoterpenes, acetone and organic aerosol mass loadings at a rural location in Southwestern Ontario, Canada by Proton-Transfer-Reaction Mass Spectrometry (PTR-MS) and Aerosol Mass Spectrometry (AMS), respectively. During the three-week-long Border Air Quality and Meteorology Study in June-July 2007, air was sampled from a range of sources, including aged air from the polluted US Midwest, direct outflow from Detroit 50 km away, and clean air with higher biogenic input. After normalization to the diurnal profile of CO, a long-lived tracer, diurnal analyses show clear photochemical loss of reactive aromatics and production of oxygenated VOCs and secondary organic aerosol (SOA) during the daytime. Biogenic VOC mixing ratios increase during the daytime in accord with their light- and temperature-dependent sources. Long-lived species, such as hydrocarbon-like organic aerosol and benzene show little to no photochemical reactivity on this timescale. From the normalized diurnal profiles of VOCs, an estimate of OH concentrations during the daytime, measured O3 concentrations, and laboratory SOA yields, we calculate integrated organic aerosol production amounts associated with each measured SOA precursor. Depending on whether the SOA formation is occurring in a low- or high-NOx regime, we estimate that the biogenic gases contribute between 10 to 36 times as much SOA as do the aromatic precursors, making this a highly biogenically dominated region for SOA formation. The conclusion that biogenic SOA formation is of significance to air quality in this region is supported by detailed air quality modeling during this period (Stroud et al., 2010).

  13. Studies on the Effect of Sub-zero Temperatures on the Formation of Extremely Low Volatility Dimer Esters in Secondary Organic Aerosol from Alpha-Pinene

    NASA Astrophysics Data System (ADS)

    Kristensen, Kasper; Normann Jensen, Louise; Bilde, Merete

    2016-04-01

    The oxidation of volatile organic compounds (VOC) is considered a major source of secondary organic aerosols (SOA) in the atmosphere. Recently, extremely low volatility organic compounds, or ELVOC, formed from the oxidation of VOCs have been shown to play a crucial role in new particle formation (Ehn et al., 2014). In addition, higher molecular weight dimer esters originating from the oxidation of the biogenic VOC alpha-pinene have been observed in both laboratory-generated and ambient SOA (Kristensen et al., 2013). The low volatility of the dimer esters along with an observed rapid formation makes these high molecular weight compounds likely candidates involved in new particle formation from the oxidation of alpha-pinene. Furthermore, laboratory experiments show that the dimer esters only form in the presence of ozone, thus may be used as tracers for the ozone-initiated oxidation of alpha-pinene, and are therefore indicative of enhanced anthropogenic activities. In this work, we present the results of a series of oxidation experiments performed in the newly constructed cold-room smog chamber at Aarhus University. This unique and state-of-the-art Teflon chamber allows for atmospheric simulations of the oxidation VOCs and subsequent SOA formation at temperatures down to -16 °C. In this study, ozonolysis and photochemical oxidations of alpha-pinene are performed at temperatures ranging from +20 to -16 °C. Chemical characterization of the formed SOA is performed using liquid chromatography coupled to quadrupole time-of-flight mass spectrometry. The results show significant differences in the chemical composition related to the experiment temperature. In particularly, the concentration of the high molecular weight dimer esters showed to be highly affected by temperature. Interestingly, preliminary results show higher formation of dimer esters related to increased SOA formation rate, thus indicating that these particle-phase ELVOCs may be linked with new particle

  14. Modelling non-equilibrium secondary organic aerosol formation and evaporation with the aerosol dynamics, gas- and particle-phase chemistry kinetic multilayer model ADCHAM

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Roldin, P.; Eriksson, A. C.; Nordin, E. Z.

    2014-08-11

    We have developed the novel Aerosol Dynamics, gas- and particle- phase chemistry model for laboratory CHAMber studies (ADCHAM). The model combines the detailed gas phase Master Chemical Mechanism version 3.2, an aerosol dynamics and particle phase chemistry module (which considers acid catalysed oligomerization, heterogeneous oxidation reactions in the particle phase and non-ideal interactions between organic compounds, water and inorganic ions) and a kinetic multilayer module for diffusion limited transport of compounds between the gas phase, particle surface and particle bulk phase. In this article we describe and use ADCHAM to study: 1) the mass transfer limited uptake of ammonia (NH3)more » and formation of organic salts between ammonium (NH4+) and carboxylic acids (RCOOH), 2) the slow and almost particle size independent evaporation of α-pinene secondary organic aerosol (SOA) particles, and 3) the influence of chamber wall effects on the observed SOA formation in smog chambers.« less

  15. Investigation of a Particle into Liquid Sampler to Study the Formation & Ageing of Secondary Organic Aerosol

    NASA Astrophysics Data System (ADS)

    Pereira, K. L.; Hamilton, J. F.; Rickard, A. R.; Bloss, W. J.; Alam, M. S.; Camredon, M.; Munoz, A.; Vazquez, M.; Rodenas, M.; Vera, T.; Borrás, E.

    2012-12-01

    The atmospheric oxidation of Volatile Organic Compounds (VOCs) in the presence of NOx results in the formation of tropospheric ozone and Secondary Organic Aerosol (SOA) [Hallquist et al., 2009]. Whilst SOA is known to affect both climate and human health, the VOC oxidation pathways leading to SOA formation are poorly understood [Solomon et al., 2007]. This is in part due to the vast number and the low concentration of SOA species present in the ambient atmosphere. It has been estimated as many as 10,000 to 100,000 VOCs have been detected in the atmosphere, all of which can undergo photo-chemical oxidation and contribute to SOA formation [Goldstein and Galbally, 2007]. Atmospheric simulation chambers such as the EUropean PHOtoREactor (EUPHORE) in Valencia, Spain, are often used to study SOA formation from a single VOC precursor under controlled conditions. SOA composition and formation can be studied using online techniques such as Aerosol Mass Spectrometry (AMS), which provide high time resolution but limited structural information [Zhang et al., 2007]. Offline techniques, such as collection onto filters, extraction and subsequent analysis, provide detailed SOA composition but only usually one or two samples per experiment. In this work we report time resolved SOA composition analysis using a Particle into Liquid Sampler (PILS) followed by Liquid Chromatography Ion-Trap Mass Spectrometry (LC-IT-MS/MS) and Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FTICR-MS/MS). Experiments were performed at EUPHORE investigating the formation and composition of Methyl Chavicol SOA. Methyl Chavicol (also known as Estragole) was identified as the highest floral emission from an oil palm plantation in Malaysian Borneo and has also been observed in US pine forests [Bouvier-Brown et al., 2009; Misztal et al., 2010]. Previous studies indicate a high SOA yield from Methyl Chavicol at around 40 % [Lee et al., 2006], however currently there have been very few literature

  16. Effects of inorganic seeds on secondary organic aerosol formation from photochemical oxidation of acetone in a chamber

    NASA Astrophysics Data System (ADS)

    Ge, Shuangshuang; Xu, Yongfu; Jia, Long

    2017-12-01

    Photochemical oxidations of acetone were studied under different inorganic seed (NaCl, (NH4)2SO4 and NaNO3) conditions in a self-made chamber. The results show that no secondary organic aerosol (SOA) can be formed in the experiments either in the absence of artificially added seed particles or in the presence of solid status of the added particles. Liquid water content is the key factor for the formation of SOA in the experiments with seeds. The amount of SOA was only about 4-7 μg m-3 in the experiments with the initial acetone of ∼15 ppm under different seed conditions. The analysis of SOA compositions by Exactive-Orbitrap mass spectrometer equipped with electro-spray interface (ESI-MS) shows that chlorine-containing and sulfur-containing compounds were detected in SOA formed from the experiments with NaCl and (NH4)2SO4 seeds, respectively, which were not identified in SOA from those with NaNO3. The compositions of SOA were mainly esters, organonitrates, hydroperoxides, etc. It is concluded that inorganic seed particles participated into the formation of SOA. Acetone SOA was mainly formed in the aqueous phase in which dissolved SOA precursors underwent further oxidation reactions, esterification reactions and/or radical-radical reactions. Our experiments further demonstrate that low-molecular-weight VOCs, such as acetone, can form SOA under certain conditions in the atmosphere, although their contributions to SOA may not be large.

  17. Onyx embolization for the endovascular treatment of infectious and traumatic aneurysms involving the cranial and cerebral vasculature.

    PubMed

    Jadhav, Ashutosh P; Pryor, Johnny C; Nogueira, Raul G

    2013-11-01

    Onyx is a liquid non-adhesive viscous embolic agent ideal for slow targeted injections which is currently approved for the treatment of intracranial aneurysms and arteriovenous malformations. We performed a single-center retrospective analysis of consecutive patients who underwent off-label use of Onyx as the single embolic agent for the treatment of traumatic or infectious pseudoaneurysms involving the cerebral or cranial vasculature. A total of nine pseudoaneurysms treated by Onyx embolization were identified. Six of the pseudoaneurysms were post-surgical, one of the pseudoaneurysms was traumatic and two were infectious in nature. The mean pseudoaneurysm size was 5.9 mm (range 2-10 mm). Onyx-34 was used in all cases. Following treatment there was complete exclusion of all pseudoaneurysms including their inflow and outflow zones. Our experience demonstrates the efficacy and applicability of the use of Onyx in the treatment of complex traumatic and mycotic pseudoaneurysms involving the cerebral and cranial vascular tree.

  18. CSI 3.0: a web server for identifying secondary and super-secondary structure in proteins using NMR chemical shifts

    PubMed Central

    Hafsa, Noor E.; Arndt, David; Wishart, David S.

    2015-01-01

    The Chemical Shift Index or CSI 3.0 (http://csi3.wishartlab.com) is a web server designed to accurately identify the location of secondary and super-secondary structures in protein chains using only nuclear magnetic resonance (NMR) backbone chemical shifts and their corresponding protein sequence data. Unlike earlier versions of CSI, which only identified three types of secondary structure (helix, β-strand and coil), CSI 3.0 now identifies total of 11 types of secondary and super-secondary structures, including helices, β-strands, coil regions, five common β-turns (type I, II, I′, II′ and VIII), β hairpins as well as interior and edge β-strands. CSI 3.0 accepts experimental NMR chemical shift data in multiple formats (NMR Star 2.1, NMR Star 3.1 and SHIFTY) and generates colorful CSI plots (bar graphs) and secondary/super-secondary structure assignments. The output can be readily used as constraints for structure determination and refinement or the images may be used for presentations and publications. CSI 3.0 uses a pipeline of several well-tested, previously published programs to identify the secondary and super-secondary structures in protein chains. Comparisons with secondary and super-secondary structure assignments made via standard coordinate analysis programs such as DSSP, STRIDE and VADAR on high-resolution protein structures solved by X-ray and NMR show >90% agreement between those made with CSI 3.0. PMID:25979265

  19. CSI 3.0: a web server for identifying secondary and super-secondary structure in proteins using NMR chemical shifts.

    PubMed

    Hafsa, Noor E; Arndt, David; Wishart, David S

    2015-07-01

    The Chemical Shift Index or CSI 3.0 (http://csi3.wishartlab.com) is a web server designed to accurately identify the location of secondary and super-secondary structures in protein chains using only nuclear magnetic resonance (NMR) backbone chemical shifts and their corresponding protein sequence data. Unlike earlier versions of CSI, which only identified three types of secondary structure (helix, β-strand and coil), CSI 3.0 now identifies total of 11 types of secondary and super-secondary structures, including helices, β-strands, coil regions, five common β-turns (type I, II, I', II' and VIII), β hairpins as well as interior and edge β-strands. CSI 3.0 accepts experimental NMR chemical shift data in multiple formats (NMR Star 2.1, NMR Star 3.1 and SHIFTY) and generates colorful CSI plots (bar graphs) and secondary/super-secondary structure assignments. The output can be readily used as constraints for structure determination and refinement or the images may be used for presentations and publications. CSI 3.0 uses a pipeline of several well-tested, previously published programs to identify the secondary and super-secondary structures in protein chains. Comparisons with secondary and super-secondary structure assignments made via standard coordinate analysis programs such as DSSP, STRIDE and VADAR on high-resolution protein structures solved by X-ray and NMR show >90% agreement between those made with CSI 3.0. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

  20. Primary Emission and the Potential of Secondary Aerosol Formation from Chinese Gasoline Engine Exhaust

    NASA Astrophysics Data System (ADS)

    Hu, Min; Peng, Jianfei; Qin, Yanhong; Du, Zhuofei; Li, Mengjin; Zheng, Rong; Zheng, Jing; Shang, Dongjie; Lu, Sihua; Wu, Yusheng; Zeng, Limin; Guo, Song; Shao, Min; Wang, Yinhui; Shuai, Shijin

    2017-04-01

    Along with the urbanization and economic growth, vehicle population in China reached 269 million, ranked the second in the world in 2015. Gasoline vehicle is identified to be the main source for urban PM2.5 in China, accounting for 15%-31%. In this study the impact of fuel components on PM2.5 and volatile organic compounds (VOCs) emissions from a gasoline port fuel injection (PFI) engine and a gasoline direct injection (GDI) engine are discussed. Results show that, higher proportion of aromatics, alkenes or sulfur in gasoline fuel will lead to higher PM emissions. The PM from the PFI engine mainly consists of OC and a small amount of EC and inorganic ions, while the PM discharge from the GDI engine mainly consists of EC, OM and a small amount of inorganic ions. Since the GDI engines can reduce fuel consumption and CO2 emissions, and it would become more and more popular in the near future. The characteristics of POM component, emission factors and source profile were investigated from GDI engine, particularly focused on the effect of engine speed, load and the catalyst, which will be very much helpful for source identification as source indicators. Chamber experiments were conducted to quantify the potential of secondary aerosol formation from exhaust of a PFI gasoline engine and China V gasoline fuel. During 4-5 h simulation, equivalent to10 days of atmospheric photo-oxidation in Beijing, the extreme SOA production was 426 ± 85 mg/kg fuel, with high precursors and OH exposure. 14% of SOA measured in the chamber experiments could be explained through the oxidation of speciated single-ring aromatics. Unspeciated precursors, such as intermediate-volatility organic compounds and semi-volatility organic compounds, might be significant for SOA formation from gasoline VOCs. We concluded that reduction of emissions of aerosol precursor gases from vehicles is essential to mediate pollution in China.

  1. Secondary organic aerosol formation from photochemical aging of light-duty gasoline vehicle exhausts in a smog chamber

    NASA Astrophysics Data System (ADS)

    Liu, T.; Wang, X.; Deng, W.; Hu, Q.; Ding, X.; Zhang, Y.; He, Q.; Zhang, Z.; Lü, S.; Bi, X.; Chen, J.; Yu, J.

    2015-08-01

    In China, a rapid increase in passenger vehicles has led to the growing concern of vehicle exhaust as an important source of anthropogenic secondary organic aerosol (SOA) in megacities hard hit by haze. In this study, the SOA formation of emissions from two idling light-duty gasoline vehicles (LDGVs) (Euro 1 and Euro 4) operated in China was investigated in a 30 m3 smog chamber. Five photo-oxidation experiments were carried out at 25 °C with relative humidity at around 50 %. After aging at an OH exposure of 5 × 106 molecules cm-3 h, the formed SOA was 12-259 times as high as primary organic aerosol (POA). The SOA production factors (PF) were 0.001-0.044 g kg-1 fuel, comparable with those from the previous studies at comparable OH exposure. This quite lower OH exposure than that in typical atmospheric conditions might however lead to the underestimation of the SOA formation potential from LDGVs. Effective SOA yields in this study were well fit by a one-product gas-particle partitioning model but quite lower than those of a previous study investigating SOA formation from three idling passenger vehicles (Euro 2-4). Traditional single-ring aromatic precursors and naphthalene could explain 51-90 % of the formed SOA. Unspeciated species such as branched and cyclic alkanes might be the possible precursors for the unexplained SOA. A high-resolution time-of-flight aerosol mass spectrometer was used to characterize the chemical composition of SOA. The relationship between f43 (ratio of m/z 43, mostly C2H3O+, to the total signal in mass spectrum) and f44 (mostly CO2+) of the gasoline vehicle exhaust SOA is similar to the ambient semi-volatile oxygenated organic aerosol (SV-OOA). We plot the O : C and H : C molar ratios of SOA in a Van Krevelen diagram. The slopes of ΔH : C / ΔO : C ranged from -0.59 to -0.36, suggesting that the oxidation chemistry in these experiments was a combination of carboxylic acid and alcohol/peroxide formation.

  2. Public health impacts of secondary particulate formation from aromatic hydrocarbons in gasoline

    PubMed Central

    2013-01-01

    Background Aromatic hydrocarbons emitted from gasoline-powered vehicles contribute to the formation of secondary organic aerosol (SOA), which increases the atmospheric mass concentration of fine particles (PM2.5). Here we estimate the public health burden associated with exposures to the subset of PM2.5 that originates from vehicle emissions of aromatics under business as usual conditions. Methods The PM2.5 contribution from gasoline aromatics is estimated using the Community Multiscale Air Quality (CMAQ) modeling system and the results are compared to ambient measurements from the literature. Marginal PM2.5 annualized concentration changes are used to calculate premature mortalities using concentration-response functions, with a value of mortality reduction approach used to monetize the social cost of mortality impacts. Morbidity impacts are qualitatively discussed. Results Modeled aromatic SOA concentrations from CMAQ fall short of ambient measurements by approximately a factor of two nationwide, with strong regional differences. After accounting for this model bias, the estimated public health impacts from exposure to PM2.5 originating from aromatic hydrocarbons in gasoline lead to a central estimate of approximately 3800 predicted premature mortalities nationwide, with estimates ranging from 1800 to over 4700 depending on the specific concentration-response function used. These impacts are associated with total social costs of $28.2B, and range from $13.6B to $34.9B in 2006$. Conclusions These preliminary quantitative estimates indicate particulates from vehicular emissions of aromatic hydrocarbons demonstrate a nontrivial public health burden. The results provide a baseline from which to evaluate potential public health impacts of changes in gasoline composition. PMID:23425393

  3. Case report and systematic literature review of a novel etiology of sinistral portal hypertension presenting with UGI bleeding: Left gastric artery pseudoaneurysm compressing the splenic vein treated by embolization of the pseudoaneurysm.

    PubMed

    Hakim, Seifeldin; Bortman, Jared; Orosey, Molly; Cappell, Mitchell S

    2017-03-01

    A novel case is reported of upper gastrointestinal (UGI) bleeding from sinistral portal hypertension, caused by a left gastric artery (LGA) pseudoaneurysm (PA) compressing the splenic vein (SV) that was successfully treated with PA embolization. A 41-year-old man with previous medical history of recurrent, alcoholic pancreatitis presented with several episodes of hematemesis and abdominal pain for 48 hours. Physical examination revealed a soft abdomen, with no abdominal bruit, no pulsatile abdominal mass, and no stigmata of chronic liver disease. The hemoglobin declined acutely from 12.3 to 9.3 g/dL. Biochemical parameters of liver function and routine coagulation profile were entirely within normal limits. Abdominal CT revealed a 5-cm-wide peripancreatic mass compressing the stomach and constricting the SV. Esophagogastroduodenoscopy showed blood oozing from portal hypertensive gastropathy, small nonbleeding gastric cardial and fundal varices, gastric compression from the extrinsic mass, and no esophageal varices. MRCP and angiography showed that the mass was vascular, arose from the LGA, compressed the mid SV without SV thrombosis, and caused sinistral portal hypertension. At angiography, the PA was angioembolized and occluded. The patient has been asymptomatic with no further bleeding and a stable hemoglobin level during 8 weeks of follow-up. Literature review of the 14 reported cases of LGA PA revealed that this report of acute UGI bleeding from sinistral portal hypertension from a LGA PA constricting the SV is novel; one previously reported patient had severe anemia without acute UGI bleeding associated with sinistral portal hypertension from a LGA PA. A patient presented with UGI bleeding from sinistral portal hypertension from a LGA PA compressing the SV that was treated by angiographic obliteration of the PA which relieved the SV compression and arrested the UGI bleeding. Primary therapy for this syndrome should be addressed to obliterate the PA and not

  4. Odorant Sensory Input Modulates DNA Secondary Structure Formation and Heterogeneous Ribonucleoprotein Recruitment on the Tyrosine Hydroxylase and Glutamic Acid Decarboxylase 1 Promoters in the Olfactory Bulb.

    PubMed

    Wang, Meng; Cai, Elizabeth; Fujiwara, Nana; Fones, Lilah; Brown, Elizabeth; Yanagawa, Yuchio; Cave, John W

    2017-05-03

    Adaptation of neural circuits to changes in sensory input can modify several cellular processes within neurons, including neurotransmitter biosynthesis levels. For a subset of olfactory bulb interneurons, activity-dependent changes in GABA are reflected by corresponding changes in Glutamate decarboxylase 1 ( Gad1 ) expression levels. Mechanisms regulating Gad1 promoter activity are poorly understood, but here we show that a conserved G:C-rich region in the mouse Gad1 proximal promoter region both recruits heterogeneous nuclear ribonucleoproteins (hnRNPs) that facilitate transcription and forms single-stranded DNA secondary structures associated with transcriptional repression. This promoter architecture and function is shared with Tyrosine hydroxylase ( Th ), which is also modulated by odorant-dependent activity in the olfactory bulb. This study shows that the balance between DNA secondary structure formation and hnRNP binding on the mouse Th and Gad1 promoters in the olfactory bulb is responsive to changes in odorant-dependent sensory input. These findings reveal that Th and Gad1 share a novel transcription regulatory mechanism that facilitates sensory input-dependent regulation of dopamine and GABA expression. SIGNIFICANCE STATEMENT Adaptation of neural circuits to changes in sensory input can modify several cellular processes within neurons, including neurotransmitter biosynthesis levels. This study shows that transcription of genes encoding rate-limiting enzymes for GABA and dopamine biosynthesis ( Gad1 and Th , respectively) in the mammalian olfactory bulb is regulated by G:C-rich regions that both recruit heterogeneous nuclear ribonucleoproteins (hnRNPs) to facilitate transcription and form single-stranded DNA secondary structures associated with repression. hnRNP binding and formation of DNA secondary structure on the Th and Gad1 promoters are mutually exclusive, and odorant sensory input levels regulate the balance between these regulatory features. These

  5. Reconstitution of a secondary cell wall in a secondary cell wall-deficient Arabidopsis mutant.

    PubMed

    Sakamoto, Shingo; Mitsuda, Nobutaka

    2015-02-01

    The secondary cell wall constitutes a rigid frame of cells in plant tissues where rigidity is required. Deposition of the secondary cell wall in fiber cells contributes to the production of wood in woody plants. The secondary cell wall is assembled through co-operative activities of many enzymes, and their gene expression is precisely regulated by a pyramidal cascade of transcription factors. Deposition of a transmuted secondary cell wall in empty fiber cells by expressing selected gene(s) in this cascade has not been attempted previously. In this proof-of-concept study, we expressed chimeric activators of 24 transcription factors that are preferentially expressed in the stem, in empty fiber cells of the Arabidopsis nst1-1 nst3-1 double mutant, which lacks a secondary cell wall in fiber cells, under the control of the NST3 promoter. The chimeric activators of MYB46, SND2 and ANAC075, as well as NST3, reconstituted a secondary cell wall with different characteristics from those of the wild type in terms of its composition. The transgenic lines expressing the SND2 or ANAC075 chimeric activator showed increased glucose and xylose, and lower lignin content, whereas the transgenic line expressing the MYB46 chimeric activator showed increased mannose content. The expression profile of downstream genes in each transgenic line was also different from that of the wild type. This study proposed a new screening strategy to identify factors of secondary wall formation and also suggested the potential of the artificially reconstituted secondary cell walls as a novel raw material for production of bioethanol and other chemicals. © The Author 2014. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists.

  6. Influence of Intense secondary aerosol formation and long range transport on aerosol chemistry and properties in the Seoul Metropolitan Area during spring time: Results from KORUS-AQ

    NASA Astrophysics Data System (ADS)

    Kim, H.; Zhang, Q.

    2017-12-01

    Non-refractory submicrometer particulate matter (NR-PM1) was measured in the Seoul Metropolitan Area (SMA), Korea, using an HR-ToF-AMS from April 14 to June 15, 2016, as a part of the KORUS-AQ campaign. The average concentration of PM1 was 22.1 µg m-3, which was composed of 44% organics, 20% SO4, 17% NO3, and 12 % NH4. Organics had an average O/C ratio of 0.49 and an average OM/OC ratio of 1.82. Four distinct sources of OA were identified via PMF analysis of the HR-ToF-AMS data: hydrocarbon like OA (HOA), cooking OA (COA),semi-volatile oxygenated OA (SV-OOA) and a low volatility oxygenated OA (LV-OOA). Our results indicate that air quality in SMA during KORUS-AQ was influenced strongly by secondary aerosol formation with SO4, NO3, NH4, SV-OOA, and LV-OOA together accounting for 76% of the PM1 mass. Due to high temperature and elevated ozone concentrations, photochemical reactions during daytime promoted the formation of SV-OOA, LV-OOA and SO4. In addition, aqueous-phase or heterogeneous reactions likely promoted efficient formation of NO3 whereas gas-to-particle partitioning processes appeared to have enhanced nighttime SV-OOA and NO3 formation. From May 20 to May 23, LV-OOA was significantly enhanced and accounted for up to 41% of the PM1 mass. Since this intense LV-OOA formation event was associated with large enhancement of VOCs, high concentration of Ox , strong solar radiation, and stagnant conditions, it appeared to be related to local photochemical formation. We also have investigated the formation and evolution mechanisms of severe haze episodes. Unlike the cases observed in winter when haze episodes were mainly caused by intense local emissions coupled with stagnant meteorological conditions, the spring haze events observed in this study appeared to be attributed by both regional and local factors. For example, episodes of long range transport of plumes were followed by calm meteorology conditions, which promoted the formation and accumulation of local

  7. Bandwidth reduction for video-on-demand broadcasting using secondary content insertion

    NASA Astrophysics Data System (ADS)

    Golynski, Alexander; Lopez-Ortiz, Alejandro; Poirier, Guillaume; Quimper, Claude-Guy

    2005-01-01

    An optimal broadcasting scheme under the presence of secondary content (i.e. advertisements) is proposed. The proposed scheme works both for movies encoded in a Constant Bit Rate (CBR) or a Variable Bit Rate (VBR) format. It is shown experimentally that secondary content in movies can make Video-on-Demand (VoD) broadcasting systems more efficient. An efficient algorithm is given to compute the optimal broadcasting schedule with secondary content, which in particular significantly improves over the best previously known algorithm for computing the optimal broadcasting schedule without secondary content.

  8. Onyx embolization of an intraosseous pseudoaneurysm of the middle meningeal artery in a patient with meningiomatosis, McCune-Albright syndrome, and gray platelet syndrome.

    PubMed

    Settecase, Fabio; Nicholson, Andrew D; Amans, Matthew R; Higashida, Randall T; Halbach, Van V; Cooke, Daniel L; Dowd, Christopher F; Hetts, Steven W

    2016-03-01

    A 13-year-old boy with meningiomatosis, McCune-Albright syndrome, and gray platelet syndrome presented with an enlarging "lump" on his right forehead. A head CT scan revealed a polyostotic fibrous dysplasia involving the entire skull. A 3.4-cm right frontal osseous cavity and an overlying right forehead subcutaneous soft-tissue mass were seen, measuring 5.2 cm in diameter and 1.6 cm thick. Ultrasound of the cavity and overlying mass showed swirling of blood and an arterialized waveform. MRI revealed an en plaque meningioma underlying the cavity. An intraosseous pseudoaneurysm fed by 3 distal anterior division branches of the right middle meningeal artery (MMA) with contrast extravasation was found on angiography. Two MMA feeders were embolized with Onyx, with anterograde filling of the intraosseous cavity with Onyx. A small pocket of residual intracavity contrast filling postembolization from a smaller third MMA feeder eventually thrombosed and the forehead lump regressed.

  9. On the Formation of Sludge Intermetallic Particles in Secondary Aluminum Alloys

    NASA Astrophysics Data System (ADS)

    Ferraro, Stefano; Bjurenstedt, Anton; Seifeddine, Salem

    2015-08-01

    The primary precipitation of Fe-rich intermetallics in AlSi9Cu3(Fe) type alloys is studied for different Fe, Mn, and Cr contents and cooling rates. Differential scanning calorimetry, thermal analysis, and interrupted solidification with a rapid quenching technique were used in combination in order to assess the nucleation temperature of sludge particles, as well as to follow their evolution. The results revealed that the sludge nucleation temperature and the release of latent heat during sludge formation are functions of Fe, Mn, and Cr levels in the molten alloy ( i.e., the sludge factor, SF) and cooling rate. Moreover, it can be concluded that sensitivity to sludge formation is not affected by cooling rate; i.e., a decrease in the SF will reduce sludge nucleation temperature to the same extent for a higher cooling rate as for a lower cooling rate. The sludge formation temperature detected will assist foundries in setting the optimal molten metal temperature for preventing sludge formation in holding furnaces and plunger systems.

  10. Influence of intense secondary aerosol formation and long-range transport on aerosol chemistry and properties in the Seoul Metropolitan Area during spring time: results from KORUS-AQ

    NASA Astrophysics Data System (ADS)

    Kim, Hwajin; Zhang, Qi; Heo, Jongbae

    2018-05-01

    Non-refractory submicrometer particulate matter (NR-PM1) was measured in the Seoul Metropolitan Area (SMA), Korea, using an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) from 14 April to 15 June 2016, as a part of the Korea-US Air Quality Study (KORUS-AQ) campaign. This was the first highly time-resolved, real-time measurement study of springtime aerosol in SMA and the results reveal valuable insights into the sources and atmospheric processes that contribute to PM pollution in this region. The average concentration of submicrometer aerosol (PM1 = NR-PM1 + black carbon (BC)) was 22.1 µg m-3, which was composed of 44 % organics, 20 % sulfate, 17 % nitrate, 12 % ammonium, and 7 % BC. Organics had an average atomic oxygen-to-carbon (O / C) ratio of 0.49 and an average organic mass-to-carbon (OM/OC) ratio of 1.82. Four distinct sources of OA were identified via positive matrix factorization (PMF) analysis of the HR-ToF-AMS data: vehicle emissions represented by a hydrocarbon-like OA factor (HOA; O / C = 0.15; 17 % of OA mass), food cooking activities represented by a cooking-influenced OA factor (COA; O / C = 0.19; 22 % of OA mass), and secondary organic aerosol (SOA) represented by a semi-volatile oxygenated OA factor (SV-OOA; O / C = 0.44; 27 % of OA mass) and a low-volatility oxygenated OA factor (LV-OOA; O / C = 0.91; 34 % of OA mass). Our results indicate that air quality in SMA during KORUS-AQ was influenced strongly by secondary aerosol formation, with sulfate, nitrate, ammonium, SV-OOA, and LV-OOA together accounting for 76 % of the PM1 mass. In particular, the formation of LV-OOA and sulfate was mainly promoted by elevated ozone concentrations and photochemical reactions during daytime, whereas SV-OOA and nitrate formation was contributed by both nocturnal processing of VOC and nitrogen oxides, respectively, and daytime photochemical reactions. In addition, lower nighttime temperature promoted gas-to-particle partitioning of

  11. Secondary water pore formation for proton transport in a ClC exchanger revealed by an atomistic molecular-dynamics simulation.

    PubMed

    Ko, Youn Jo; Jo, Won Ho

    2010-05-19

    Several prokaryotic ClC proteins have been demonstrated to function as exchangers that transport both chloride ions and protons simultaneously in opposite directions. However, the path of the proton through the ClC exchanger, and how the protein brings about the coupled movement of both ions are still unknown. In this work, we use an atomistic molecular dynamics (MD) simulation to demonstrate that a previously unknown secondary water pore is formed inside an Escherichia coli ClC exchanger. The secondary water pore is bifurcated from the chloride ion pathway at E148. From the systematic simulations, we determined that the glutamate residue exposed to the intracellular solution, E203, plays an important role as a trigger for the formation of the secondary water pore, and that the highly conserved tyrosine residue Y445 functions as a barrier that separates the proton from the chloride ion pathways. Based on our simulation results, we conclude that protons in the ClC exchanger are conducted via a water network through the secondary water pore, and we propose a new mechanism for the coupled transport of chloride ions and protons. It has been reported that several members of ClC proteins are not just channels that simply transport chloride ions across lipid bilayers; rather, they are exchangers that transport both the chloride ion and proton in opposite directions. However, the ion transit pathways and the mechanism of the coupled movement of these two ions have not yet been unveiled. In this article, we report a new finding (to our knowledge) of a water pore inside a prokaryotic ClC protein as revealed by computer simulation. This water pore is bifurcated from the putative chloride ion, and water molecules inside the new pore connect two glutamate residues that are known to be key residues for proton transport. On the basis of our simulation results, we conclude that the water wire that is formed inside the newly found pore acts as a proton pathway, which enables us to

  12. Formation of a repressive complex in the mammalian circadian clock is mediated by the secondary pocket of CRY1

    DOE PAGES

    Michael, Alicia K.; Fribourgh, Jennifer L.; Chelliah, Yogarany; ...

    2017-01-31

    The basic helix-loop-helix PAS domain (bHLH-PAS) transcription factor CLOCK:BMAL1 (brain and muscle Arnt-like protein 1) sits at the core of the mammalian circadian transcription/translation feedback loop. Precise control of CLOCK:BMAL1 activity by coactivators and repressors establishes the ~24-h periodicity of gene expression. Formation of a repressive complex, defined by the core clock proteins cryptochrome 1 (CRY1):CLOCK:BMAL1, plays an important role controlling the switch from repression to activation each day. Here in this paper, we show that CRY1 binds directly to the PAS domain core of CLOCK: BMAL1, driven primarily by interaction with the CLOCK PAS-B domain. Integrative modeling and solutionmore » X-ray scattering studies unambiguously position a key loop of the CLOCK PAS-B domain in the secondary pocket of CRY1, analogous to the antenna chromophore-binding pocket of photolyase. CRY1 docks onto the transcription factor alongside the PAS domains, extending above the DNA-binding bHLH domain. Single point mutations at the interface on either CRY1 or CLOCK disrupt formation of the ternary complex, highlighting the importance of this interface for direct regulation of CLOCK:BMAL1 activity by CRY1.« less

  13. Key Role of Nitrate in Phase Transitions of Urban Particles: Implications of Important Reactive Surfaces for Secondary Aerosol Formation

    NASA Astrophysics Data System (ADS)

    Sun, Jiaxing; Liu, Lei; Xu, Liang; Wang, Yuanyuan; Wu, Zhijun; Hu, Min; Shi, Zongbo; Li, Yongjie; Zhang, Xiaoye; Chen, Jianmin; Li, Weijun

    2018-01-01

    Ammonium sulfate (AS) and ammonium nitrate (AN) are key components of urban fine particles. Both field and model studies showed that heterogeneous reactions of SO2, NO2, and NH3 on wet aerosols accelerated the haze formation in northern China. However, little is known on phase transitions of AS-AN containing haze particles. Here hygroscopic properties of laboratory-generated AS-AN particles and individual particles collected during haze events in an urban site were investigated using an individual particle hygroscopicity system. AS-AN particles showed a two-stage deliquescence at mutual deliquescence relative humidity (MDRH) and full deliquescence relative humidity (DRH) and three physical states: solid before MDRH, solid-aqueous between MDRH and DRH, and aqueous after DRH. During hydration, urban haze particles displayed a solid core and aqueous shell at RH = 60-80% and aqueous phase at RH > 80%. Most particles were in aqueous phase at RH > 50% during dehydration. Our results show that AS content in individual particles determines their DRH and AN content determines their MDRH. AN content increase can reduce MDRH, which indicates occurrence of aqueous shell at lower RH. The humidity-dependent phase transitions of nitrate-abundant urban particles are important to provide reactive surfaces of secondary aerosol formation in the polluted air.

  14. The role of extremophile in the redox reaction of Fe and As relating with the formation of secondary phase mineral in extreme environment, Norris Geyser Basin, Yellowstone National Park, USA

    NASA Astrophysics Data System (ADS)

    Koo, T. H.; Kim, J. Y.; Park, K. R.; Jung, D. H.; Geesey, G. G.; Kim, J. W.

    2015-12-01

    Redox reaction associated with microbial elemental respiration is a ubiquitous process in sediments and suspended particles at various temperatures or pH/Eh conditions. Particularly, changes in elemental redox states (structural or dissolved elemental form) induced by microbial respiration result in the unexpected biogeochemical reactions in the light of biotic/abiotic mineralization. The objective of the present study is, therefore to investigate the secondary phase mineralization through a-/biogeochemical Fe and As redox cycling in the acido-hyperhtermal Norris Geyser Basin (NGB) in Yellowstone National Park, USA, typical of the extreme condition. X-ray diffraction, scanning electron microscope with energy dispersive x-ray spectroscopy, X-ray absorption near edge structure, inductively coupled plasma-atomic emission spectrometer and liquid chromatography with ICP-mass spectroscopy with filtrated supernatant were performed for the mineralogical and hydro-geochemical analysis. The clay slurry collected from the active hot-spring of the NGB area (pH=3.5 and Temperature=78 ℃) was incubated with ("enrichment") or without the growth medium ("natural"). The control was prepared in the same condition except adding the glutaraldehyde to eliminate the microbial activity. The secondary phase mineral formation of the oxidative phase of Fe and As, and K identified as 'Pharmacosiderite' only appeared in the enrichment set suggesting a role of extremophiles in the mineral formation. The considerable population of Fe-oxidizer (Metallosphera yellowstonensis MK-1) and As-oxidizer (Sulfurihydrogenibium sp.) was measured by phylogenetic analysis in the present study area. The inhibition of As-oxidation in the low pH conditions was reported in the previous study, however the As-redox reaction was observed and consequently, precipitated the Pharmacosiderite only in the enrichment set suggesting a biotic mineralization. The present study collectively suggests that the microbial

  15. Investigating the influences of SO2 and NH3 levels on isoprene-derived secondary organic aerosol formation using conditional sampling approaches

    NASA Astrophysics Data System (ADS)

    Lin, Y.-H.; Knipping, E. M.; Edgerton, E. S.; Shaw, S. L.; Surratt, J. D.

    2013-08-01

    Filter-based PM2.5 samples were chemically analyzed to investigate secondary organic aerosol (SOA) formation from isoprene in a rural atmosphere of the southeastern US influenced by both anthropogenic sulfur dioxide (SO2) and ammonia (NH3) emissions. Daytime PM2.5 samples were collected during summer 2010 using conditional sampling approaches based on pre-defined high and low SO2 or NH3 thresholds. Known molecular-level tracers for isoprene SOA formation, including 2-methylglyceric acid, 3-methyltetrahydrofuran-3,4-diols, 2-methyltetrols, C5-alkene triols, dimers, and organosulfate derivatives, were identified and quantified by gas chromatography coupled to electron ionization mass spectrometry (GC/EI-MS) and ultra performance liquid chromatography coupled to electrospray ionization high-resolution quadrupole time-of-flight mass spectrometry (UPLC/ESI-HR-Q-TOFMS). Mass concentrations of six isoprene low-NOx SOA tracers contributed to 12-19% of total organic matter (OM) in PM2.5 samples collected during the sampling period, indicating the importance of the hydroxyl radical (OH)-initiated oxidation (so-called photooxidation) of isoprene under low-NOx conditions that lead to SOA formation through reactive uptake of gaseous isoprene epoxydiols (IEPOX) in this region. The contribution of the IEPOX-derived SOA tracers to total organic matter was enhanced by 1.4% (p = 0.012) under high-SO2 sampling scenarios, although only weak associations between aerosol acidity and mass of IEPOX SOA tracers were observed. This suggests that IEPOX-derived SOA formation might be modulated by other factors simultaneously, rather than only aerosol acidity. No clear associations between isoprene SOA formation and high or low NH3 conditional samples were found. Positive correlations between sulfate aerosol loadings and IEPOX-derived SOA tracers for samples collected under all conditions indicates that sulfate aerosol could be a surrogate for surface accommodation in the uptake of IEPOX onto

  16. EVIDENCE FOR ORGANOSULFATES IN SECONDARY ORGANIC AEROSOL

    EPA Science Inventory

    Recent work has shown that particle-phase reactions contribute to the formation of secondary organic aerosol (SOA), with enhancements of SOA yields in the presence of acidic seed aerosol. In this study, the chemical composition of SOA from the photooxidations of α-pinene and isop...

  17. A geochemical view into continental palaeotemperatures of the end-Permian using oxygen and hydrogen isotope composition of secondary silica in chert rubble breccia: Kaibab Formation, Grand Canyon (USA).

    PubMed

    Kenny, Ray

    2018-01-16

    The upper carbonate member of the Kaibab Formation in northern Arizona (USA) was subaerially exposed during the end Permian and contains fractured and zoned chert rubble lag deposits typical of karst topography. The karst chert rubble has secondary (authigenic) silica precipitates suitable for estimating continental weathering temperatures during the end Permian karst event. New oxygen and hydrogen isotope ratios of secondary silica precipitates in the residual rubble breccia: (1) yield continental palaeotemperature estimates between 17 and 22 °C; and, (2) indicate that meteoric water played a role in the crystallization history of the secondary silica. The continental palaeotemperatures presented herein are broadly consistent with a global mean temperature estimate of 18.2 °C for the latest Permian derived from published climate system models. Few data sets are presently available that allow even approximate quantitative estimates of regional continental palaeotemperatures. These data provide a basis for better understanding the end Permian palaeoclimate at a seasonally-tropical latitude along the western shoreline of Pangaea.

  18. Density functional study of molecular interactions in secondary structures of proteins.

    PubMed

    Takano, Yu; Kusaka, Ayumi; Nakamura, Haruki

    2016-01-01

    Proteins play diverse and vital roles in biology, which are dominated by their three-dimensional structures. The three-dimensional structure of a protein determines its functions and chemical properties. Protein secondary structures, including α-helices and β-sheets, are key components of the protein architecture. Molecular interactions, in particular hydrogen bonds, play significant roles in the formation of protein secondary structures. Precise and quantitative estimations of these interactions are required to understand the principles underlying the formation of three-dimensional protein structures. In the present study, we have investigated the molecular interactions in α-helices and β-sheets, using ab initio wave function-based methods, the Hartree-Fock method (HF) and the second-order Møller-Plesset perturbation theory (MP2), density functional theory, and molecular mechanics. The characteristic interactions essential for forming the secondary structures are discussed quantitatively.

  19. Characterization of prototype secondary lithium battery

    NASA Technical Reports Server (NTRS)

    Somoano, R.

    1980-01-01

    The performance characteristics of ambient temperature secondary lithium batteries were determined through continuous cycle tests with periodic current and voltage measurements. Cycle life of the lithium anode was found to be an important problem area as was the formation of dentrite breakage and subsequent shorting. Energy density was increased by using more efficient cathode structures.

  20. Modeling the formation and properties of traditional and non-traditional secondary organic aerosol: problem formulation and application to aircraft exhaust

    NASA Astrophysics Data System (ADS)

    Jathar, S. H.; Miracolo, M. A.; Presto, A. A.; Donahue, N. M.; Adams, P. J.; Robinson, A. L.

    2012-10-01

    We present a methodology to model secondary organic aerosol (SOA) formation from the photo-oxidation of unspeciated low-volatility organics (semi-volatile and intermediate volatile organic compounds) emitted by combustion systems. It is formulated using the volatility basis-set approach. Unspeciated low-volatility organics are classified by volatility and then allowed to react with the hydroxyl radical. The new methodology allows for larger reductions in volatility with each oxidation step than previous volatility basis set models, which is more consistent with the addition of common functional groups and similar to those used by traditional SOA models. The methodology is illustrated using data collected during two field campaigns that characterized the atmospheric evolution of dilute gas-turbine engine emissions using a smog chamber. In those experiments, photo-oxidation formed a significant amount of SOA, much of which could not be explained based on the emissions of traditional speciated precursors; we refer to the unexplained SOA as non-traditional SOA (NT-SOA). The NT-SOA can be explained by emissions of unspeciated low-volatility organics measured using sorbents. We show that the parameterization proposed by Robinson et al. (2007) is unable to explain the timing of the NT-SOA formation in the aircraft experiments because it assumes a very modest reduction in volatility of the precursors with every oxidation reaction. In contrast the new method better reproduces the NT-SOA formation. The NT-SOA yields estimated for the unspeciated low-volatility organic emissions in aircraft exhaust are similar to literature data for large n-alkanes and other low-volatility organics. The estimated yields vary with fuel composition (Jet Propellent-8 versus Fischer-Tropsch) and engine load (ground idle versus non-ground idle). The framework developed here is suitable for modeling SOA formation from emissions from other combustion systems.

  1. Characteristics of PCDD/F emissions from secondary copper smelting industry.

    PubMed

    Hung, Pao Chen; Chang, Chia Chia; Chang, Shu Hao; Chang, Moo Been

    2015-01-01

    Characteristics and mechanisms of PCDD/F formation with different feed materials in secondary copper smelting industry are investigated. The results indicate that PCDD/Fs are significantly formed even with the reaction time less than 0.1s, especially when the material containing high residues (Cu3) is fed. High copper content (65±2%) in the feed material enhances PCDD/F formation rate. Memory effect and de novo synthesis are two important mechanisms leading to PCDD/F formation. PCDD/F concentrations at the cyclone's inlet are between 2.92 and 12.4ng-TEQNm(-3) and increase with increasing residue content in the feed material. Two regions are identified for high potential of PCDD/F formation including the brass melt surface of the induction furnace and piping before the induced draft fan of the inlet hood. PCDD/Fs in flue gas are effectively removed with a cyclone and bag filter at low operating temperatures (<60°C) to meet the emission limit of 1.0ng-TEQNm(-3). 1,2,3,4,6,7,8-HpCDF has the largest mass fraction of PCDD/Fs and can serve as a fingerprint for emissions from secondary copper smelting processes. The total emission factor of PCDD/Fs from flue gas, residual and fly ash in the secondary copper smelting process investigated is 22.01μg-TEQtonne(-1). Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Model analysis of secondary organic aerosol formation by glyoxal in laboratory studies: the case for photoenhanced chemistry.

    PubMed

    Sumner, Andrew J; Woo, Joseph L; McNeill, V Faye

    2014-10-21

    The reactive uptake of glyoxal by atmospheric aerosols is believed to be a significant source of secondary organic aerosol (SOA). Several recent laboratory studies have been performed with the goal of characterizing this process, but questions remain regarding the effects of photochemistry on SOA growth. We applied GAMMA (McNeill et al. Environ. Sci. Technol. 2012, 46, 8075-8081), a photochemical box model with coupled gas-phase and detailed aqueous aerosol-phase chemistry, to simulate aerosol chamber studies of SOA formation by the uptake of glyoxal by wet aerosol under dark and irradiated conditions (Kroll et al. J. Geophys. Res. 2005, 110 (D23), 1-10; Volkamer et al. Atmos. Chem. Phys. 2009, 9, 1907-1928; Galloway et al. Atmos. Chem. Phys. 2009, 9, 3331- 306 3345 and Geophys. Res. Lett. 2011, 38, L17811). We find close agreement between simulated SOA growth and the results of experiments conducted under dark conditions using values of the effective Henry's Law constant of 1.3-5.5 × 10(7) M atm(-1). While irradiated conditions led to the production of some organic acids, organosulfates, and other oxidation products via well-established photochemical mechanisms, these additional product species contribute negligible aerosol mass compared to the dark uptake of glyoxal. Simulated results for irradiated experiments therefore fell short of the reported SOA mass yield by up to 92%. This suggests a significant light-dependent SOA formation mechanism that is not currently accounted for by known bulk photochemistry, consistent with recent laboratory observations of SOA production via photosensitizer chemistry.

  3. Sequestration of Soil Carbon as Secondary Carbonates (Invited)

    NASA Astrophysics Data System (ADS)

    Lal, R.

    2013-12-01

    Rattan Lal Carbon Management and Sequestration Center The Ohio State University Columbus, OH 43210 USA Abstract World soils, the major carbon (C) reservoir among the terrestrial pools, contain soil organic C (SOC) and soil inorganic C (SIC). The SIC pool is predominant in soils of arid and semi-arid regions. These regions cover a land area of about 4.9x109 ha. The SIC pool in soils containing calcic and petrocalcic horizons is estimated at about 695-748 Pg (Pg = 1015 g = 1 gigaton) to 1-m depth. There are two types of carbonates. Lithogenic or primary carbonates are formed from weathering of carbonaceous rocks. Pedogenic or secondary carbonates are formed by dissolution of CO2 in the soil air to form carbonic acid and precipitation as carbonates of Ca+2 or Mg+2. It is the availability of Ca+2 or Mg+2 from outside the ecosystem that is essential to sequester atmospheric CO2. Common among outside sources of Ca+2 or Mg+2 are irrigation water, aerial deposition, sea breeze, fertilizers, manure and other amendments. The decomposition of SOC and root respiration may increase the partial pressure of CO2 in the soil air and lead to the formation of HCO_3^- upon dissolution in H20. Precipitation of secondary carbonates may result from decreased partial pressure of CO2 in the sub-soil, increased concentration of Ca+2, Mg+2 and HCO_3^- in soil solution, and decreased soil moisture content by evapotranspiration. Transport of bicarbonates in irrigated soils and subsequent precipitation above the ground water (calcrete), activity of termites and other soil fauna, and management of urban soils lead to formation of secondary carbonates. On a geologic time scale, weathering of silicate minerals and transport of the by-products into the ocean is a geological process of sequestration of atmospheric CO2. Factors affecting formation of secondary carbonates include land use, and soil and crop management including application of biosolids, irrigation and the quality of irrigation water

  4. Secondary organic aerosol formation from isoprene photo-oxidation during cloud condensation-evaporation cycles (CUMULUS project)

    NASA Astrophysics Data System (ADS)

    Brégonzio-Rozier, Lola; Siekmann, Frank; Giorio, Chiara; Temime-Roussel, Brice; Pangui, Edouard; Morales, Sébastien; Gratien, Aline; Ravier, Sylvain; Monod, Anne; Doussin, Jean-Francois

    2014-05-01

    It is acknowledged that atmospheric photo-oxidation of Volatile Organic Compounds (VOC) leads to the formation of less volatile oxidized species. These compounds can undergo gas-to-particle conversion, leading to the formation of Secondary Organic Aerosols (SOA) in the atmosphere. Nevertheless, some of these oxidized species are water soluble and could also partition into cloud droplets. Higher molecular weight and less volatile compounds could be produced in the aqueous phase and remain in the particle phase after water evaporation (Ervens et al., 2011). The aim of the present work is to study SOA formation in the presence of cloud droplets during isoprene photo-oxidation. To this end, an original multiphase approach in a simulation chamber was set up in order to investigate the chemistry occurring in the gaseous, particulate and aqueous phases, and the exchange between these phases. Experiments were performed, within the CUMULUS project (CloUd MULtiphase chemistry of organic compoUndS in the troposphere), in the CESAM chamber (Wang et al., 2011). This chamber was designed to investigate multiphase processes under realistic actinic flux, and accurate control of both temperature and relative humidity. A specific protocol was set up to produce cloud events in the simulation chamber exhibiting a significant lifetime in the presence of light (10-12 minutes). By using this protocol, many clouds could be generated in a single experiment. In each experiment, around 800 ppb of isoprene was injected in the chamber together with HONO under dry conditions before irradiation. A Fourier Transform Infrared Spectrometer (FTIR), a Proton Transfer Reaction Mass Spectrometer (PTR-TOF-MS) and NOx and O3 analyzers were used to analyze gas-phase composition. Dried SOA size distributions and total concentrations were measured by a Scanning Mobility Particle Sizer (SMPS). An Aerodyne High Resolution Time-Of-Flight Aerosol Mass Spectrometer (HR-TOF-AMS) was also used to investigate

  5. Formation of secondary organic aerosols from gas-phase emissions of heated cooking oils

    NASA Astrophysics Data System (ADS)

    Liu, Tengyu; Li, Zijun; Chan, ManNin; Chan, Chak K.

    2017-06-01

    Cooking emissions can potentially contribute to secondary organic aerosol (SOA) but remain poorly understood. In this study, formation of SOA from gas-phase emissions of five heated vegetable oils (i.e., corn, canola, sunflower, peanut and olive oils) was investigated in a potential aerosol mass (PAM) chamber. Experiments were conducted at 19-20 °C and 65-70 % relative humidity (RH). The characterization instruments included a scanning mobility particle sizer (SMPS) and a high-resolution time-of-flight aerosol mass spectrometer (HR-TOF-AMS). The efficiency of SOA production, in ascending order, was peanut oil, olive oil, canola oil, corn oil and sunflower oil. The major SOA precursors from heated cooking oils were related to the content of monounsaturated fat and omega-6 fatty acids in cooking oils. The average production rate of SOA, after aging at an OH exposure of 1. 7 × 1011 molecules cm-3 s, was 1. 35 ± 0. 30 µg min-1, 3 orders of magnitude lower compared with emission rates of fine particulate matter (PM2. 5) from heated cooking oils in previous studies. The mass spectra of cooking SOA highly resemble field-derived COA (cooking-related organic aerosol) in ambient air, with R2 ranging from 0.74 to 0.88. The average carbon oxidation state (OSc) of SOA was -1.51 to -0.81, falling in the range between ambient hydrocarbon-like organic aerosol (HOA) and semi-volatile oxygenated organic aerosol (SV-OOA), indicating that SOA in these experiments was lightly oxidized.

  6. The Global Contribution of Secondary Craters on the Icy Satellites

    NASA Astrophysics Data System (ADS)

    Hoogenboom, T.; Johnson, K. E.; Schenk, P.

    2014-12-01

    At present, surface ages of bodies in the Outer Solar System are determined only from crater size-frequency distributions (a method dependent on an understanding of the projectile populations responsible for impact craters in these planetary systems). To derive accurate ages using impact craters, the impactor population must be understood. Impact craters in the Outer Solar System can be primary, secondary or sesquinary. The contribution of secondary craters to the overall population has recently become a "topic of interest." Our objective is to better understand the contribution of dispersed secondary craters to the small crater populations, and ultimately that of small comets to the projectile flux on icy satellites in general. We measure the diameters of obvious secondary craters (determined by e.g. irregular crater shape, small size, clustering) formed by all primary craters on Ganymede for which we have sufficiently high resolution data to map secondary craters. Primary craters mapped range from approximately 40 km to 210 km. Image resolution ranges from 45 to 440 m/pixel. Bright terrain on Ganymede is our primary focus. These resurfaced terrains have relatively low crater densities and serve as a basis for characterizing secondary populations as a function of primary size on an icy body for the first time. Although focusing on Ganymede, we also investigate secondary crater size, frequency, distribution, and formation, as well as secondary crater chain formation on icy satellites throughout the Saturnian and Jovian systems principally Rhea. We compare our results to similar studies of secondary cratering on the Moon and Mercury. Using Galileo and Voyager data, we have identified approximately 3,400 secondary craters on Ganymede. In some cases, we measured crater density as a function of distance from a primary crater. Because of the limitations of the Galileo data, it is necessary to extrapolate from small data sets to the global population of secondary craters

  7. A large source of low-volatility secondary organic aerosol.

    PubMed

    Ehn, Mikael; Thornton, Joel A; Kleist, Einhard; Sipilä, Mikko; Junninen, Heikki; Pullinen, Iida; Springer, Monika; Rubach, Florian; Tillmann, Ralf; Lee, Ben; Lopez-Hilfiker, Felipe; Andres, Stefanie; Acir, Ismail-Hakki; Rissanen, Matti; Jokinen, Tuija; Schobesberger, Siegfried; Kangasluoma, Juha; Kontkanen, Jenni; Nieminen, Tuomo; Kurtén, Theo; Nielsen, Lasse B; Jørgensen, Solvejg; Kjaergaard, Henrik G; Canagaratna, Manjula; Maso, Miikka Dal; Berndt, Torsten; Petäjä, Tuukka; Wahner, Andreas; Kerminen, Veli-Matti; Kulmala, Markku; Worsnop, Douglas R; Wildt, Jürgen; Mentel, Thomas F

    2014-02-27

    Forests emit large quantities of volatile organic compounds (VOCs) to the atmosphere. Their condensable oxidation products can form secondary organic aerosol, a significant and ubiquitous component of atmospheric aerosol, which is known to affect the Earth's radiation balance by scattering solar radiation and by acting as cloud condensation nuclei. The quantitative assessment of such climate effects remains hampered by a number of factors, including an incomplete understanding of how biogenic VOCs contribute to the formation of atmospheric secondary organic aerosol. The growth of newly formed particles from sizes of less than three nanometres up to the sizes of cloud condensation nuclei (about one hundred nanometres) in many continental ecosystems requires abundant, essentially non-volatile organic vapours, but the sources and compositions of such vapours remain unknown. Here we investigate the oxidation of VOCs, in particular the terpene α-pinene, under atmospherically relevant conditions in chamber experiments. We find that a direct pathway leads from several biogenic VOCs, such as monoterpenes, to the formation of large amounts of extremely low-volatility vapours. These vapours form at significant mass yield in the gas phase and condense irreversibly onto aerosol surfaces to produce secondary organic aerosol, helping to explain the discrepancy between the observed atmospheric burden of secondary organic aerosol and that reported by many model studies. We further demonstrate how these low-volatility vapours can enhance, or even dominate, the formation and growth of aerosol particles over forested regions, providing a missing link between biogenic VOCs and their conversion to aerosol particles. Our findings could help to improve assessments of biosphere-aerosol-climate feedback mechanisms, and the air quality and climate effects of biogenic emissions generally.

  8. A large source of low-volatility secondary organic aerosol

    NASA Astrophysics Data System (ADS)

    Ehn, Mikael; Thornton, Joel A.; Kleist, Einhard; Sipilä, Mikko; Junninen, Heikki; Pullinen, Iida; Springer, Monika; Rubach, Florian; Tillmann, Ralf; Lee, Ben; Lopez-Hilfiker, Felipe; Andres, Stefanie; Acir, Ismail-Hakki; Rissanen, Matti; Jokinen, Tuija; Schobesberger, Siegfried; Kangasluoma, Juha; Kontkanen, Jenni; Nieminen, Tuomo; Kurtén, Theo; Nielsen, Lasse B.; Jørgensen, Solvejg; Kjaergaard, Henrik G.; Canagaratna, Manjula; Maso, Miikka Dal; Berndt, Torsten; Petäjä, Tuukka; Wahner, Andreas; Kerminen, Veli-Matti; Kulmala, Markku; Worsnop, Douglas R.; Wildt, Jürgen; Mentel, Thomas F.

    2014-02-01

    Forests emit large quantities of volatile organic compounds (VOCs) to the atmosphere. Their condensable oxidation products can form secondary organic aerosol, a significant and ubiquitous component of atmospheric aerosol, which is known to affect the Earth's radiation balance by scattering solar radiation and by acting as cloud condensation nuclei. The quantitative assessment of such climate effects remains hampered by a number of factors, including an incomplete understanding of how biogenic VOCs contribute to the formation of atmospheric secondary organic aerosol. The growth of newly formed particles from sizes of less than three nanometres up to the sizes of cloud condensation nuclei (about one hundred nanometres) in many continental ecosystems requires abundant, essentially non-volatile organic vapours, but the sources and compositions of such vapours remain unknown. Here we investigate the oxidation of VOCs, in particular the terpene α-pinene, under atmospherically relevant conditions in chamber experiments. We find that a direct pathway leads from several biogenic VOCs, such as monoterpenes, to the formation of large amounts of extremely low-volatility vapours. These vapours form at significant mass yield in the gas phase and condense irreversibly onto aerosol surfaces to produce secondary organic aerosol, helping to explain the discrepancy between the observed atmospheric burden of secondary organic aerosol and that reported by many model studies. We further demonstrate how these low-volatility vapours can enhance, or even dominate, the formation and growth of aerosol particles over forested regions, providing a missing link between biogenic VOCs and their conversion to aerosol particles. Our findings could help to improve assessments of biosphere-aerosol-climate feedback mechanisms, and the air quality and climate effects of biogenic emissions generally.

  9. Formation of N-nitrosodimethylamine (NDMA) from dimethylamine during chlorination.

    PubMed

    Mitch, William A; Sedlak, David L

    2002-02-15

    Chlorine disinfection of secondary wastewater effluent and drinking water can result in the production of the potent carcinogen N-nitrosodimethylamine (NDMA) at concentrations of approximately 100 and 10 parts per trillion (ng/L), respectively. Laboratory experiments with potential NDMA precursors indicate that NDMA formation can form during the chlorination of dimethylamine and other secondary amines. The formation of NDMA during chlorination may involve the slow formation of 1,1-dimethylhydrazine by the reaction of monochloramine and dimethylamine followed by its rapid oxidation to NDMA and other products including dimethylcyanamide and dimethylformamide. Other pathways also lead to NDMA formation during chlorination such as the reaction of sodium hypochlorite with dimethylamine. However, the rate of NDMA formation is approximately an order of magnitude slower than that observed when monochloramine reacts with dimethylamine. The reaction exhibits a strong pH dependence due to competing reactions. It may be possible to reduce NDMA formation during chlorination by removing ammonia prior to chlorination, by breakpoint chlorination, or by avoidance of the use of monochloramine for drinking water disinfection.

  10. Aortic Replacement with Sutureless Intraluminal Grafts

    PubMed Central

    Lemole, Gerald M.

    1990-01-01

    To avoid the anastomotic complications and long cross-clamp times associated with standard suture repair of aortic lesions, we have implanted sutureless intraluminal grafts in 122 patients since 1976. Forty-nine patients had disorders of the ascending aorta, aortic arch, or both: their operative mortality was 14% (7 patients), and the group's 5-year actuarial survival rate has been 64%. There have been no instances of graft dislodgment, graft infection, aortic bleeding, or pseudoaneurysm formation. Forty-two patients had disorders of the descending aorta and thoracoabdominal aorta: their early mortality was 10% (4 patients), and the group's 5-year actuarial survival rate has been 56%. There was 1 early instance of graft dislodgment, but no pseudoaneurysm formation, graft erosion, aortic bleeding, intravascular hemolysis, or permanent deficits in neurologic, renal, or vascular function. Thirty-one patients had the sutureless intraluminal graft implanted in the abdominal aortic position: their early mortality was 6% (2 patients), and the 5-year actuarial survival rate for this group has been 79%. There were no instances of renal failure, ischemic complication, postoperative paraplegia, pseudoaneurysm, or anastomotic true aneurysm. Our recent efforts have been directed toward developing an adjustable spool that can adapt to the widest aorta or the narrowest aortic arch vessel; but in the meanwhile, the present sutureless graft yields shorter cross-clamp times, fewer intraoperative complications, and both early and late results as satisfactory as those afforded by traditional methods of aortic repair. (Texas Heart Institute Journal 1990; 17:302-9) Images PMID:15227522

  11. Endovascular Therapy of Traumatic Vascular Lesions of the Head and Neck

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Diaz-Daza, Orlando; Arraiza, Francisco J.; Barkley, John M.

    Pseudoaneurysm and fistula formation are well-documented complications of arterial vascular injury and may be associated with significant morbidity and mortality. The purpose of this manuscript is to review the presentation and therapy of patients with traumatic vascular injuries of the head and neck. Eight patients were admitted to a Level 1 Trauma Center and diagnostic angiography of the carotid artery and vertebral circulation was performed. The mechanisms of injury included motor vehicle accident, gunshot wound,stab wound and aggravated assault. Cause of trauma, vascular lesion,endovascular therapy and outcome were analyzed retrospectively. The angiographic findings, clinical presentation and hospital course were reviewed.more » There were eight patients, seven males and one female, aged 17-65. Four patients (50%) had multiple lesions; four had pseudoaneurysms, two with fistula formation and two with active arterial hemorrhage. A total of 17 lesions were embolized using coils,Polyvinyl Alcohol (PVA), Gelfoam or a combination. Two of the 17 lesions received stents. Six of the eight patients remained clinically improved or stable at varying follow-up intervals. One of the four patients who presented with penetrating trauma and neurological deficits had resolution of right hemiplegia at the 8{sup th}month follow-up. One of the four patients who sustained blunt trauma and carotid-cavernous fistula presented with a new pseudoaneurysm at the 2-month post-embolization follow-up. The evolution of diagnostics neuroangiogaphic techniques provides opportunities for endovascular therapy of traumatic vascular lesions of the head and neck that are minimally invasive, attractive options in selected cases.« less

  12. Graft union formation in grapevine induces transcriptional changes related to cell wall modification, wounding, hormone signalling, and secondary metabolism

    PubMed Central

    Cookson, Sarah Jane; Clemente Moreno, Maria José; Hevin, Cyril; Nyamba Mendome, Larissa Zita; Delrot, Serge; Trossat-Magnin, Claudine; Ollat, Nathalie

    2013-01-01

    Grafting is particularly important to the cultivation of perennial crops such as grapevine (Vitis vinifera) because rootstocks can provide resistance to soil-borne pests and diseases as well as improve tolerance to some abiotic stresses. Successful grafting is a complex biochemical and structural process beginning with the adhesion of the two grafted partners, followed by callus formation and the establishment of a functional vascular system. At the molecular level, the sequence of events underlying graft union formation remains largely uncharacterized. The present study investigates the transcriptome of grapevine rootstock and graft interface tissues sampled 3 d and 28 d after grafting of over-wintering stems in the spring. Many genes were differentially expressed over time, from 3 d to 28 d after grafting, which could be related to the activation of stem growth and metabolic activity in the spring. This hypothesis is supported by the up-regulation of many genes associated with cell wall synthesis, and phloem and xylem development. Generally, there was an up-regulation of gene expression in the graft interface tissue compared with the rootstock, particularly genes involved in cell wall synthesis, secondary metabolism, and signalling. Although there was overlap between the genes differentially expressed over time (from 3 d to 28 d after grafting) with the gene differentially expressed between the rootstock and the graft interface, numerous graft interface-specific genes were identified. PMID:23698628

  13. Modeling the formation and aging of secondary organic aerosols in Los Angeles during CalNex 2010

    NASA Astrophysics Data System (ADS)

    Hayes, P. L.; Carlton, A. G.; Baker, K. R.; Ahmadov, R.; Washenfelder, R. A.; Alvarez, S.; Rappenglück, B.; Gilman, J. B.; Kuster, W. C.; de Gouw, J. A.; Zotter, P.; Prévôt, A. S. H.; Szidat, S.; Kleindienst, T. E.; Offenberg, J. H.; Jimenez, J. L.

    2014-12-01

    Four different parameterizations for the formation and evolution of secondary organic aerosol (SOA) are evaluated using a 0-D box model representing the Los Angeles Metropolitan Region during the CalNex 2010 field campaign. We constrain the model predictions with measurements from several platforms and compare predictions with particle and gas-phase observations from the CalNex Pasadena ground site. That site provides a unique opportunity to study aerosol formation close to anthropogenic emission sources with limited recirculation. The model SOA formed only from the oxidation of VOCs (V-SOA) is insufficient to explain the observed SOA concentrations, even when using SOA parameterizations with multi-generation oxidation that produce much higher yields than have been observed in chamber experiments, or when increasing yields to their upper limit estimates accounting for recently reported losses of vapors to chamber walls. The Community Multiscale Air Quality (WRF-CMAQ) model (version 5.0.1) provides excellent predictions of secondary inorganic particle species but underestimates the observed SOA mass by a factor of 25 when an older VOC-only parameterization is used, which is consistent with many previous model-measurement comparisons for pre-2007 anthropogenic SOA modules in urban areas. Including SOA from primary semi-volatile and intermediate volatility organic compounds (P-S/IVOCs) following the parameterizations of Robinson et al. (2007), Grieshop et al. (2009), or Pye and Seinfeld (2010) improves model/measurement agreement for mass concentration. When comparing the three parameterizations, the Grieshop et al. (2009) parameterization more accurately reproduces both the SOA mass concentration and oxygen-to-carbon ratio inside the urban area. Our results strongly suggest that other precursors besides VOCs, such as P-S/IVOCs, are needed to explain the observed SOA concentrations in Pasadena. All the parameterizations over-predict urban SOA formation at long

  14. Novel methods for predicting gas-particle partitioning during the formation of secondary organic aerosol

    NASA Astrophysics Data System (ADS)

    Wania, F.; Lei, Y. D.; Wang, C.; Abbatt, J. P. D.; Goss, K.-U.

    2014-12-01

    Several methods have been presented in the literature to predict an organic chemical's equilibrium partitioning between the water insoluble organic matter (WIOM) component of aerosol and the gas phase, Ki,WIOM, as a function of temperature. They include (i) polyparameter linear free energy relationships calibrated with empirical aerosol sorption data, as well as (ii) the solvation models implemented in SPARC and (iii) the quantum-chemical software COSMOtherm, which predict solvation equilibria from molecular structure alone. We demonstrate that these methods can be used to predict Ki,WIOM for large numbers of individual molecules implicated in secondary organic aerosol (SOA) formation, including those with multiple functional groups. Although very different in their theoretical foundations, these methods give remarkably consistent results for the products of the reaction of normal alkanes with OH, i.e. their partition coefficients Ki,WIOM generally agree within one order of magnitude over a range of more than ten orders of magnitude. This level of agreement is much better than that achieved by different vapour pressure estimation methods that are more commonly used in the SOA community. Also, in contrast to the agreement between vapour pressure estimates, the agreement between the Ki,WIOM estimates does not deteriorate with increasing number of functional groups. Furthermore, these partitioning coefficients Ki,WIOM predicted SOA mass yields in agreement with those measured in chamber experiments of the oxidation of normal alkanes. If a Ki,WIOM prediction method was based on one or more surrogate molecules representing the solvation properties of the mixed OM phase of SOA, the choice of those molecule(s) was found to have a relatively minor effect on the predicted Ki,WIOM, as long as the molecule(s) are not very polar. This suggests that a single surrogate molecule, such as 1-octanol or a hypothetical SOA structure proposed by Kalberer et al. (2004), may often be

  15. Alkyl–Alkyl Suzuki Cross-Couplings of Unactivated Secondary Alkyl Chlorides**

    PubMed Central

    Lu, Zhe; Fu, Gregory C.

    2010-01-01

    The first method for achieving alkyl–alkyl Suzuki reactions of unactivated secondary alkyl chlorides has been developed. Carbon–carbon bond formation occurs under mild conditions (at room temperature) with the aid of commercially available catalyst components. This method has proved to be versatile: without modification, it can be applied to Suzuki reactions of secondary and primary alkyl bromides and iodides, as well as primary alkyl chlorides. Mechanistic investigations suggest that oxidative addition is not the turnover-limiting step of the catalytic cycle for unactivated secondary alkyl iodides and bromides, whereas it may be (partially) for chlorides. PMID:20715038

  16. Character Education/Formation in Catholic Schools (K-12).

    ERIC Educational Resources Information Center

    Marine, Robert A.

    Noting that character formation within Catholic education has undergone several changes over the last 10 years, this paper examines character education and character formation as they are currently implemented in Catholic elementary and secondary schools. Section 1 of the paper considers the definition of character, and traces the development of…

  17. Hydrogen or formate: Alternative key players in methanogenic degradation.

    PubMed

    Schink, Bernhard; Montag, Dominik; Keller, Anja; Müller, Nicolai

    2017-06-01

    Hydrogen and formate are important electron carriers in methanogenic degradation in anoxic environments such as sediments, sewage sludge digestors and biogas reactors. Especially in the terminal steps of methanogenesis, they determine the energy budgets of secondary (syntrophically) fermenting bacteria and their methanogenic partners. The literature provides considerable data on hydrogen pool sizes in such habitats, but little data exist for formate concentrations due to technical difficulties in formate determination at low concentration. Recent evidence from biochemical and molecular biological studies indicates that several secondary fermenters can use both hydrogen and formate for electron release, and may do so even simultaneously. Numerous strictly anaerobic bacteria contain enzymes which equilibrate hydrogen and formate pools to energetically equal values, and recent measurements in sewage digestors and biogas reactors indicate that - beyond occasional fluctuations - the pool sizes of hydrogen and formate are indeed energetically nearly equivalent. Nonetheless, a thermophilic archaeon from a submarine hydrothermal vent, Thermococcus onnurineus, can obtain ATP from the conversion of formate to hydrogen plus bicarbonate at 80°C, indicating that at least in this extreme environment the pools of formate and hydrogen are likely to be sufficiently different to support such an unusual type of energy conservation. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  18. OZONE-ISOPRENE REACTION: RE-EXAMINATION OF THE FORMATION OF SECONDARY ORGANIC AEROSOL

    EPA Science Inventory

    The reaction of ozone and isoprene has been studied to examine physical and chemical characteristics of the secondary organic aerosol formed. Using a scanning mobility particle sizer, the volume distribution of the aerosol was found in the range 0.05 - 0.2 µm. The aerosol yield w...

  19. Multiple secondary islands formation in nonlinear evolution of double tearing mode simulations

    NASA Astrophysics Data System (ADS)

    Guo, W.; Ma, J.; Yu, Z.

    2017-03-01

    A new numerical code solving the conservative perturbed resistive magnetohydrodynamic (MHD) model is developed. Numerical tests of the ideal Kelvin-Helmholtz instability and the resistive double tearing mode (DTM) show its capability in solving linear and nonlinear MHD instabilities. The nonlinear DTM evolution in 2D geometry is numerically investigated with low guiding field B z 0 , short half-distance y 0 between the equilibrium current sheets, and small resistivity η. The interaction of islands on the two initial current sheets may generate an unstable flow driven current sheet with a high length-to-thickness aspect ratio (α), and multiple secondary islands can form. In general, the length-to-thickness aspect ratio α and the number of secondary islands increase with decreasing guide field B z 0 , decreasing half-distance y 0 , and increasing Lundquist number of the flow driven current sheet S L although the dependence may be non-monotonic. The reconnection rate dependence on S L , B z 0 , and y 0 is also investigated.

  20. Novel model of negative secondary ion formation and its use to refine the electronegativity of almost fifty elements.

    PubMed

    Wittmaack, Klaus

    2014-06-17

    This study aimed to examine the recently proposed idea that the ionic contribution to atomic bonds is essential in determining the charge state of sputtered atoms. Use was made of negative secondary ion yields reported by Wilson for a large number of elements implanted in silicon and then sputter profiled by Cs bombardment. The derived normalized ion yields (or fractions) P vary by 6 orders of magnitude, but the expected exponential dependence on the electron affinity EA is evident only vaguely. Remarkably, a correlation of similar quality is observed if the data are presented as a function of the ionization potential IP. With IP being the dominant (if not sole) contributor to the electronegativity χ, one is led to assume that P depends on the sum χ + EA. About 72% of the "nonsaturated" ion yields are in accordance with a dependence of the form P ∝ exp[(χ + EA)/ε], with ε ≅ 0.2 eV, provided the appropriate value of χ is selected from the electronegativity tables of Pauling (read in eV), Mulliken or Allen. However, each of the three sources contributes only about one-third to the favorable electronegativity data. This unsatisfactory situation initiated the idea to derive the "true" electronegativity χSIMS from the measured ion yields P(χ + EA), verified for 48 elements. Significant negative deviations of χSIMS from a smooth increase with increasing atomic number are evident for elements with special outer-shell electron configurations such as (n-1)d(g-1)ns(1) or (n-1)d(10)ns(2)np(1). The results strongly support the new model of secondary ion formation and provide means for refining electronegativity data.

  1. An extended model of heartwood secondary metabolism informed by functional genomics.

    PubMed

    Celedon, Jose M; Bohlmann, Jörg

    2018-03-01

    The development of heartwood (HW) and the associated accumulation of secondary metabolites, which are also known as 'specialized metabolites' or 'extractives', is an important feature of tree biology. Heartwood development can affect tree health with broader implications for forest health. Heartwood development also defines a variety of wood quality traits that are important in the forest industry such as durability and colour of wood products. In the bioproducts industry, HW provides a source of high-value small molecules such as fragrances and antimicrobials. The HW properties of decay resistance in living trees, durability and colour of wood products, and small molecule bioproducts are largely defined by secondary metabolites, the biosynthesis of which appears to be activated during the onset of HW formation. Traditionally, it is thought that HW formation involves a spike in the activity of secondary metabolism in parenchyma cells in a transition zone between sapwood and HW, followed by programmed cell-death. The resulting HW tissue is thought to consist entirely of dead cells. Here, we discuss a variation of existing models of HW formation, based on the recent discovery of HW-specific transcriptome signatures of terpenoid biosynthesis in sandalwood (Santalum album L.) that invokes the activity of living cells in HW.

  2. Comparison of secondary organic aerosol formation from toluene on initially wet and dry ammonium sulfate particles at moderate relative humidity

    NASA Astrophysics Data System (ADS)

    Liu, Tengyu; Huang, Dan Dan; Li, Zijun; Liu, Qianyun; Chan, ManNin; Chan, Chak K.

    2018-04-01

    The formation of secondary organic aerosol (SOA) has been widely studied in the presence of dry seed particles at low relative humidity (RH). At higher RH, initially dry seed particles can exist as wet particles due to water uptake by the seeds as well as the SOA. Here, we investigated the formation of SOA from the photooxidation of toluene using an oxidation flow reactor in the absence of NOx under a range of OH exposures on initially wet or dry ammonium sulfate (AS) seed particles at an RH of 68 %. The ratio of the SOA yield on wet AS seeds to that on dry AS seeds, the relative SOA yield, decreased from 1.31 ± 0.02 at an OH exposure of 4.66 × 1010 molecules cm-3 s to 1.01 ± 0.01 at an OH exposure of 5.28 × 1011 molecules cm-3 s. This decrease may be due to the early deliquescence of initially dry AS seeds after being coated by highly oxidized toluene-derived SOA. SOA formation lowered the deliquescence RH of AS and resulted in the uptake of water by both AS and SOA. Hence the initially dry AS seeds contained aerosol liquid water (ALW) soon after SOA formed, and the SOA yield and ALW approached those of the initially wet AS seeds as OH exposure and ALW increased, especially at high OH exposure. However, a higher oxidation state of the SOA on initially wet AS seeds than that on dry AS seeds was observed at all levels of OH exposure. The difference in mass fractions of m / z 29, 43 and 44 of SOA mass spectra, obtained using an aerosol mass spectrometer (AMS), indicated that SOA formed on initially wet seeds may be enriched in earlier-generation products containing carbonyl functional groups at low OH exposures and later-generation products containing acidic functional groups at high exposures. Our results suggest that inorganic dry seeds become at least partially deliquesced particles during SOA formation and hence that ALW is inevitably involved in the SOA formation at moderate RH. More laboratory experiments conducted with a wide variety of SOA

  3. The effect of sub-zero temperature on the formation and composition of secondary organic aerosol from ozonolysis of alpha-pinene.

    PubMed

    Kristensen, K; Jensen, L N; Glasius, M; Bilde, M

    2017-10-18

    This study presents a newly constructed temperature controlled cold-room smog chamber at Aarhus University, Denmark. The chamber is herein utilized to study the effect of sub-zero temperature on the formation and chemical composition of secondary organic aerosol (SOA) from ozone initiated oxidation of α-pinene. The chemical composition of α-pinene SOA formed from dark ozonolysis of α-pinene at 293 K and 258 K was investigated using High-Resolution Time-of-Flight Aerosol Mass Spectrometry (HR-ToF-AMS) and Ultra-High Performance Liquid Chromatography/Electrospray Ionization Quadrupole Time-of-Flight Mass Spectrometry (UHPLC/ESI-qToF-MS). For comparison, an OH-initiated oxidation experiment was performed at 293 K. In ozonolysis experiments it was found that oxygen-to-carbon (O : C) ratios were higher in the particles formed at 293 K compared to 258 K. A total of 16 different organic acids and 30 dimers esters were quantified in the collected particles composing up to 34% of the total α-pinene SOA mass with increased mass fraction of carboxylic acids in particles from α-pinene ozonolysis at 258 K compared to 293 K. In contrast, dimer esters showed suppressed formation at the sub-zero reaction temperature, thus contributing 3% to SOA mass at 258 K while contributing 9% at 293 K. SOA formed in the OH-initiated oxidation of α-pinene at 293 K resulted in low concentrations of dimer esters supporting Criegee intermediates as a possible pathway to dimer ester formation. Vapour pressure estimates of the identified carboxylic acids and dimer esters are presented and show how otherwise semi-volatile carboxylic acids at sufficiently low temperatures may classify as low or even extremely low volatile organic compounds (ELVOC), thus may add to an enhanced particle formation observed at the sub-zero temperature through gas-to-particle conversion. The change in chemical composition of the SOA particles with temperature is ascribed to a combination of effects: the decreased

  4. Plant body weight-induced secondary growth in Arabidopsis and its transcription phenotype revealed by whole-transcriptome profiling.

    PubMed

    Ko, Jae-Heung; Han, Kyung-Hwan; Park, Sunchung; Yang, Jaemo

    2004-06-01

    Wood is an important raw material and environmentally cost-effective renewable source of energy. However, the molecular biology of wood formation (i.e. secondary growth) is surprisingly understudied. A novel experimental system was employed to study the molecular regulation of secondary xylem formation in Arabidopsis. First, we demonstrate that the weight carried by the stem is a primary signal for the induction of cambium differentiation and the plant hormone, auxin, is a downstream carrier of the signal for this process. We used Arabidopsis whole-transcriptome (23 K) GeneChip analysis to examine gene expression profile changes in the inflorescent stems treated for wood formation by cultural manipulation or artificial weight application. Many of the genes up-regulated in wood-forming stems had auxin responsive cis-acting elements in their promoter region, indicating auxin-mediated regulation of secondary growth. We identified 700 genes that were differentially expressed during the transition from primary growth to secondary growth. More than 40% of the genes that were up-regulated (>5x) were associated with signal transduction and transcriptional regulation. Biological significance of these regulatory genes is discussed in light of the induction and development of secondary xylem.

  5. Enhanced CO2 electroreduction efficiency through secondary coordination effects on a pincer iridium catalyst.

    PubMed

    Ahn, Steven T; Bielinski, Elizabeth A; Lane, Elizabeth M; Chen, Yanqiao; Bernskoetter, Wesley H; Hazari, Nilay; Palmore, G Tayhas R

    2015-04-07

    An iridium(III) trihydride complex supported by a pincer ligand with a hydrogen bond donor in the secondary coordination sphere promotes the electrocatalytic reduction of CO2 to formate in water/acetonitrile with excellent Faradaic efficiency and low overpotential. Preliminary mechanistic experiments indicate formate formation is facile while product release is a kinetically difficult step.

  6. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mendez, Jose C.; Gonzalez-Llanos, Francisco

    We present a case of vertebral artery pseudoaneurysm after a posterior C1-C2 transarticular screw fixation procedure that was effectively treated with endovascular coil occlusion. Vertebral artery pseudoaneurysm complicating posterior C1-C2 transarticular fixation is extremely rare, with only one previous case having been reported previously. Endovascular occlusion is better achieved in the subacute phase of the pseudoaneurysm, when the wall of the pseudoaneurysm has matured and stabilized. Further follow-up angiographies are mandatory in order to confirm that there is no recurrence of the lesion.

  7. Stereospecific Cross-Coupling of Secondary Alkyl β-Trifluoroboratoamides

    PubMed Central

    Sandrock, Deidre L.; Jean-Gérard, Ludivine; Chen, Cheng-yi; Dreher, Spencer D.; Molander, Gary A.

    2010-01-01

    The stereospecific cross-coupling of enantioenriched non-benzylic secondary alkyl boron compounds has been achieved. The high selectivity toward product formation over an undesired β-H elimination pathway is achieved via an intramolecular coordination of an ancillary carbonyl to the metal center in the diorganopalladium intermediate. PMID:21077687

  8. Stages of Gender Education in Canadian Secondary Schools

    ERIC Educational Resources Information Center

    Zhukovskyi, Vasyl; Kostiuk, Olha

    2015-01-01

    The article deals with the issue of educational preconditions of gender education formation and development in Canadian secondary schools. On the basis of conducted scientific and pedagogical literature analysis it has been determined that gender education has undergone three main stages and is currently developing during its fourth, modern…

  9. Transcription factors PRE3 and WOX11 are involved in the formation of new lateral roots from secondary growth taproot in A. thaliana.

    PubMed

    Baesso, B; Chiatante, D; Terzaghi, M; Zenga, D; Nieminen, K; Mahonen, A P; Siligato, R; Helariutta, Y; Scippa, G S; Montagnoli, A

    2018-05-01

    The spatial deployment of lateral roots determines the ability of a plant to interact with the surrounding environment for nutrition and anchorage. This paper shows that besides the pericycle, the vascular cambium becomes active in Arabidopsis thaliana taproot at a later stage of development and is also able to form new lateral roots. To demonstrate the above, we implemented a two-step approach in which the first step leads to development of a secondary structure in A. thaliana taproot, and the second applies a mechanical stress on the vascular cambium to initiate formation of a new lateral root primordium. GUS staining showed PRE3, DR5 and WOX11 signals in the cambial zone of the root during new lateral root formation. An advanced level of wood formation, characterized by the presence of medullar rays, was achieved. Preliminary investigations suggest the involvement of auxin and two transcription factors (PRE3/ATBS1/bHLH135/TMO7 and WOX11) in the transition of some vascular cambium initials from a role as producers of xylem/phloem mother cells to founder cells of a new lateral root primordium. © 2018 German Society for Plant Sciences and The Royal Botanical Society of the Netherlands.

  10. Physico-chemical properties of aerosols in Sao Paulo, Brazil and mechanisms of secondary organic aerosol formation.

    NASA Astrophysics Data System (ADS)

    Artaxo, Paulo; Ferreira de Brito, Joel; Varanda Rizzo, Luciana; Luiza Godoy, Maria; Godoy, Jose Marcus

    2013-04-01

    Megacities emissions are increasingly becoming a global issue, where emissions from the transportation sector play an increasingly important role. Sao Paulo is a megacity with a population of about 18 million people, 7 million cars and large-scale industrial emissions. As a result of the vehicular and industrial emissions, the air quality in Sao Paulo is bellow WMO standards for aerosol particles and ozone. Many uncertainties are found on gas- and particulate matter vehicular emission factors and their following atmospheric processes, e.g. secondary organic aerosol formation. Due to the uniqueness of the vehicular fuel in Brazil, largely based on ethanol use, such characterization currently holds further uncertainties. To improve the understanding of the role of this unique emission characteristics, we are running a source apportionment study in Sao Paulo focused on the mechanisms of organic aerosol formation. One of the goals of this study is a quantitative aerosol source apportionment focused on vehicular emissions, including ethanol and gasohol (both fuels used by light-duty vehicles). This study comprises four sampling sites with continuous measurements for one year, where trace elements and organic aerosol are being measured for PM2.5 and PM10 along with real-time NOx, O3, PM10 and CO measurements. Aerosol optical properties and size distribution are being measured on a rotation basis between sampling stations. Furthermore, a Proton-Transfer-Reaction Mass Spectrometer (PTR-MS) and an Aerosol Chemical Speciation Monitor (ACSM) are used to measure in real time VOCs and aerosol composition, respectively. Trace elements were measured using XRF and OC/EC analysis was determined with a Sunset OC/EC instrument. A TSI Nephelometer with 3 wavelengths measure light scattering and a MAAP measure black carbon. Results show aerosol number concentrations ranging between 10,000 and 35,000 cm-3, mostly concentrated in the nucleation and Aitken modes, with a peak in size at 80

  11. Unexpected role of activated carbon in promoting transformation of secondary amines to N-nitrosamines.

    PubMed

    Padhye, Lokesh; Wang, Pei; Karanfil, Tanju; Huang, Ching-Hua

    2010-06-01

    Activated carbon (AC) is the most common solid phase extraction material used for analysis of nitrosamines in water. It is also widely used for the removal of organics in water treatment and as a catalyst or catalyst support in some industrial applications. In this study, it was discovered that AC materials can catalyze transformation of secondary amines to yield trace levels of N-nitrosamines under ambient aerobic conditions. All 11 commercial ACs tested in the study formed nitrosamines from secondary amines. Among the different ACs, the N-nitrosodimethylamine (NDMA) yield at pH 7.5 ranged from 0.001% to 0.01% of initial amount of aqueous dimethylamine (DMA) concentration, but at 0.05-0.29% of the amount of adsorbed DMA by AC. Nitrosamine yield increased with higher pH and for higher molecular weight secondary amines, probably because of increased adsorption of amines. Presence of oxygen was a critical factor in the transformation of secondary amines, since ACs with adsorbed secondary amines dried under air for longer period of time exhibited significantly higher nitrosamine yields. The AC-catalyzed nitrosamine formation was also observed in surface water and wastewater effluent samples. Properties of AC play an important role in the nitrosamine yields. Preliminary evaluation indicated that nitrosamine formation was higher on reduced than oxidized AC surfaces. Overall, the study results show that selecting ACs and reaction conditions are important to minimize analytical errors and undesirable formation associated with nitrosamines in water samples.

  12. A systematic review of post-secondary transition interventions for youth with disabilities.

    PubMed

    Lindsay, Sally; Lamptey, De-Lawrence; Cagliostro, Elaine; Srikanthan, Dilakshan; Mortaji, Neda; Karon, Leora

    2018-05-04

    Youth with disabilities have lower rates of enrollment and completion of post-secondary education compared with youth without disabilities. The objective of this systematic review is to understand the best practices and components of post-secondary transition programs for youth with disabilities. Systematic searches of six international databases identified 18 studies meeting our inclusion criteria (youth with a disability, aged 15-30; focusing on post-secondary education program or intervention, published from 1997 to 2017). These studies were analyzed with respect to the characteristics of the participants, methodology, results, and quality of the evidence. Among the 18 studies, 2385 participants (aged 13-28, mean 17.7 years) were represented across three countries (US, Canada, and Australia). Although the outcomes of the post-secondary transition programs varied across the studies, all of them reported an improvement in at least one of the following: college enrollment, self-determination, self-confidence, social and vocational self-efficacy, autonomy, social support, career exploration, and transition skills. The post-secondary transition programs varied in duration, length, number of sessions, and delivery format which included curriculum-based, online, immersive residential experience, mentoring, simulation, self-directed, technology-based, and multi-component. Our findings highlight that post-secondary transition programs have the potential to improve self-determination, transition skills, and post-secondary outcomes among youth with disabilities. Implications for rehabilitation Post-secondary education interventions have a beneficial influence on post-secondary and related transition outcomes in youth with disabilities. Clinicians and educators should consider having multiple components, involving several sessions that include a curriculum, immersive college residential experience, mentoring, and/or simulations in their interventions for optimum program

  13. Secondary formation of nitrated phenols: insights from observations during the Uintah Basin Winter Ozone Study (UBWOS) 2014

    NASA Astrophysics Data System (ADS)

    Yuan, B.; Liggio, J.; Wentzell, J.; Li, S.-M.; Stark, H.; Roberts, J. M.; Gilman, J.; Lerner, B.; Warneke, C.; Li, R.; Leithead, A.; Osthoff, H. D.; Wild, R.; Brown, S. S.; de Gouw, J. A.

    2015-10-01

    We describe the results from online measurements of nitrated phenols using a time of flight chemical ionization mass spectrometer (ToF-CIMS) with acetate as reagent ion in an oil and gas production region in January and February of 2014. Strong diurnal profiles were observed for nitrated phenols, with concentration maxima at night. Based on known markers (CH4, NOx, CO2), primary emissions of nitrated phenols were not important in this study. A box model was used to simulate secondary formation of phenol, nitrophenol (NP) and dinitrophenols (DNP). The box model results indicate that oxidation of aromatics in the gas phase can explain the observed concentrations of NP and DNP in this study. Photolysis was the most efficient loss pathway for NP in the gas phase. We show that aqueous-phase reactions and heterogeneous reactions were minor sources of nitrated phenols in our study. This study demonstrates that the emergence of new ToF-CIMS (including PTR-TOF) techniques allows for the measurement of intermediate oxygenates at low levels and these measurements improve our understanding of the evolution of primary VOCs in the atmosphere.

  14. Secondary formation of nitrated phenols: insights from observations during the Uintah Basin Winter Ozone Study (UBWOS) 2014

    NASA Astrophysics Data System (ADS)

    Yuan, Bin; Liggio, John; Wentzell, Jeremy; Li, Shao-Meng; Stark, Harald; Roberts, James M.; Gilman, Jessica; Lerner, Brian; Warneke, Carsten; Li, Rui; Leithead, Amy; Osthoff, Hans D.; Wild, Robert; Brown, Steven S.; de Gouw, Joost A.

    2016-02-01

    We describe the results from online measurements of nitrated phenols using a time-of-flight chemical ionization mass spectrometer (ToF-CIMS) with acetate as reagent ion in an oil and gas production region in January and February of 2014. Strong diurnal profiles were observed for nitrated phenols, with concentration maxima at night. Based on known markers (CH4, NOx, CO2), primary emissions of nitrated phenols were not important in this study. A box model was used to simulate secondary formation of phenol, nitrophenol (NP), and dinitrophenols (DNP). The box model results indicate that oxidation of aromatics in the gas phase can explain the observed concentrations of NP and DNP in this study. Photolysis was the most efficient loss pathway for NP in the gas phase. We show that aqueous-phase reactions and heterogeneous reactions were minor sources of nitrated phenols in our study. This study demonstrates that the emergence of new ToF-CIMS (including PTR-TOF) techniques allows for the measurement of intermediate oxygenates at low levels and these measurements improve our understanding on the evolution of primary VOCs in the atmosphere.

  15. High School Learning Environments: Hybrid versus Traditional Formats

    ERIC Educational Resources Information Center

    Clifton, Mary Beth

    2017-01-01

    This research study examined the effects of hybrid course format as compared to face-to-face instruction format in a high school setting. At this time, there is little research on hybrid courses in the secondary schools. The quantitative portion of this ex post facto study utilized causal comparative design. Student data was collected from teacher…

  16. Role of secondary aerosols in haze formation in summer in the Megacity Beijing.

    PubMed

    Han, Tingting; Liu, Xingang; Zhang, Yuanhang; Qu, Yu; Zeng, Limin; Hu, Min; Zhu, Tong

    2015-05-01

    A field experiment from 18 August to 8 September 2006 in Beijing, China, was carried out. A hazy day was defined as visibilitysecondary organic aerosol) concentrations. The average values with standard deviation of SO4(2-), NO3-, NH4+ and SOA were 49.8 (±31.6), 31.4 (±22.3), 25.8 (±16.6) and 8.9 (±4.1)μg/m3, respectively, during the haze episodes, which were 4.3, 3.4, 4.1, and 1.7 times those in the non-haze days. The SO4(2-), NO3-, NH4+, and SOA accounted for 15.8%, 8.8%, 7.3%, and 6.0% of the total mass concentration of PM10 during the non-haze days. The respective contributions of SNA species to PM10 rose to about 27.2%, 15.9%, and 13.9% during the haze days, while the contributions of SOA maintained the same level with a slight decrease to about 4.9%. The observed mass concentrations of SNA and SOA increased with the increase of PM10 mass concentration, however, the rate of increase of SNA was much faster than that of the SOA. The SOR (sulfur oxidation ratio) and NOR (nitrogen oxidation ratio) increased from non-haze days to hazy days, and increased with the increase of RH. High concentrations of aerosols and water vapor favored the conversion of SO2 to SO4(2-) and NO2 to NO3-, which accelerated the accumulation of the aerosols and resulted in the formation of haze in Beijing. Copyright © 2015. Published by Elsevier B.V.

  17. Secondary Social Studies: Alaska Curriculum Guide. Second Edition.

    ERIC Educational Resources Information Center

    Alaska State Dept. of Education, Juneau. Office of Curriculum Services.

    A secondary social studies model curriculum guide for Alaska is presented. The body of the guide lists topics/concepts, learning outcomes/objectives, and sample learning activities in a 3 column format. The first column, topics/concepts, describes the content area, defining the subject broadly and listing subconcepts or associated vocabulary. The…

  18. Degradation of SO 2, NO 2 and NH 3 leading to formation of secondary inorganic aerosols: An environmental chamber study

    NASA Astrophysics Data System (ADS)

    Behera, Sailesh N.; Sharma, Mukesh

    2011-08-01

    We have examined the interactions of gaseous pollutants and primary aerosols that can produce secondary inorganic aerosols. The specific objective was to estimate degradation rates of precursor gases (NH 3, NO 2 and SO 2) responsible for formation of secondary inorganic aerosols. A Teflon-based outdoor environmental chamber facility (volume 12.5 m 3) was built and checked for wall losses, leaks, solar transparency and ability to simulate photochemical reactions. The chamber was equipped with state-of-the-art instrumentation to monitor concentration-time profiles of precursor gases, ozone, and aerosol. A total of 14 experimental runs were carried out for estimating the degradation of precursor gases. The following initial conditions were maintained in the chamber: NO 2 = 246 ± 104 ppb(v), NH 3 = 548 ± 83 ppb(v), SO 2 = 238 ± 107 ppb(v), O 3 = 50 ± 11 ppb(v), PM 2.5 aerosol = 283438 ± 60524 No./litre. The concentration-time profile of gases followed first-order decay and were used for estimating degradation rates (NO 2 = 0.26 ± 0.15 h -1, SO 2 = 0.31 ± 0.17 h -1, NH 3 = 0.35 ± 0.21 h -1). We observed that degradation rates showed a statistical significant positive correlation (at 5% level of significance) with the initial PM 2.5 levels in the chamber (coefficient of correlation: 0.63 for NO 2; 0.62 for NH 3 and 0.51 for SO 2), suggesting that the existing surface of the aerosol could play a significant role in degradation of precursor gases. One or more gaseous species can be adsorbed on to the existing particles and these may undergo heterogeneous or homogeneous chemical transformation to produce secondary inorganic aerosols. Through correlation analysis, we have observed that degradation rates of precursor gases were dependent on initial molar ratio of (NH 3)/(NO 2 + SO 2), indicative of ammonia-rich and ammonia-poor situations for eventual production of ammonium salts.

  19. Modeling transcriptional networks regulating secondary growth and wood formation in forest trees

    Treesearch

    Lijun Liu; Vladimir Filkov; Andrew Groover

    2013-01-01

    The complex interactions among the genes that underlie a biological process can be modeled and presented as a transcriptional network, in which genes (nodes) and their interactions (edges) are shown in a graphical form similar to a wiring diagram. A large number of genes have been identified that are expressed during the radial woody growth of tree stems (secondary...

  20. On the importance of cotranscriptional RNA structure formation

    PubMed Central

    Lai, Daniel; Proctor, Jeff R.; Meyer, Irmtraud M.

    2013-01-01

    The expression of genes, both coding and noncoding, can be significantly influenced by RNA structural features of their corresponding transcripts. There is by now mounting experimental and some theoretical evidence that structure formation in vivo starts during transcription and that this cotranscriptional folding determines the functional RNA structural features that are being formed. Several decades of research in bioinformatics have resulted in a wide range of computational methods for predicting RNA secondary structures. Almost all state-of-the-art methods in terms of prediction accuracy, however, completely ignore the process of structure formation and focus exclusively on the final RNA structure. This review hopes to bridge this gap. We summarize the existing evidence for cotranscriptional folding and then review the different, currently used strategies for RNA secondary-structure prediction. Finally, we propose a range of ideas on how state-of-the-art methods could be potentially improved by explicitly capturing the process of cotranscriptional structure formation. PMID:24131802