757 research outputs found

    Necrotizing Infection of the Aortic Arch: Reconstruction Utilizing Unusual Extra-anatomic Bypass Grafts to Reroute Cerebral Blood Flow.

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    Destructive infections of the aortic arch and great vessels are challenging to manage. We describe a novel technique for debranching the right cerebral and upper extremity arteries via composite extra-anatomic bypasses from the femoral artery, with subsequent homograft in-line reconstruction of the arch, in a patient with Staphylococcus sepsis and necrosis of the arch and great vessels

    Hydrogen related risks within a private garage: concentration measurements in a realistic full scale experimental facility

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    ABSTRACT Next generation of hydrogen energy based vehicles is expected to come into widespread use in the near future. Various topics related to hydrogen including, production, storage, and application of hydrogen as an energy carrier, have become subjects of discussion in the framework of various European and International projects. Safety information is vital to support the successful introduction into mainstream and public acceptance of hydrogen as an energy carrier. One of such issues, which is seeking major attention is related to hydrogen powered vehicles parked inside a confined area (such as in a private garage). It is of utmost importance to predict, if uncontrolled release of hydrogen from a vehicle parked inside a confined area can create an explosive atmosphere. Subsequently, how the preventive measures can be implied to control these explosive atmospheres, if present inside a confined area? There is a little guidance currently developed for confined areas accommodating hydrogen fuelled vehicles. It is essential that mitigation measures for such conditions become established. Characterization of different scenarios those may arise in a real situation from hydrogen fuelled vehicle parked inside a garage and furthermore, the investigation of an optimal ventilation rate for hydrogen risk mitigation are some of the main objectives described in the framework of the present study. This work is an effort to provide detail experimental information's in view of establishing guidelines for hydrogen powered vehicles parked inside a private garage. The present work is developed in the framework of a European Network of Excellence HySafe and French project DRIVE. Present paper describes a purpose built realistic Garage test facility at CEA to study the dispersion of hydrogen leakage. The studied test cases evaluate the influence of injected volumes of hydrogen and the initial conditions at the leakage source on the dispersion and mixing characteristics inside the free volume of the unventilated garage. The mixing process and build-up of hydrogen concentration is measured for the duration of 24 hours. Due to safety reasons, helium gas is used to simulate the hydrogen dispersion characteristics

    Predictors of early and late mortality following open extent IV thoracoabdominal aortic aneurysm repair in a large contemporary single-center experience

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    ObjectiveThe primary purpose of this study was to examine outcomes following open repair of extent IV thoracoabdominal aortic aneurysms (TAAAs) at a single university hospital. As a secondary aim, comparison was made to patients who underwent open abdominal aortic aneurysm (AAA) repair with supraceliac clamping but without left renal artery bypass to assess the effect of left renal artery bypass on outcomes.MethodsPatients undergoing open extent IV TAAA repair from 1998 to 2008 were identified (n = 108). Primary outcomes were 30-day and long-term survival. Secondary outcomes were major complication, renal failure, and postoperative change in renal function. A second analysis was performed, comparing patients undergoing extent IV TAAA repair with patients undergoing AAA repair with supraceliac clamping but without left renal artery bypass (n = 50).ResultsEighty-three men (76.9%) and 25 women (23.1%), with a mean age of 72.9 years, underwent open extent IV TAAA repair. Nine patients (8.3%) were ruptured. Mean aneurysm maximal diameter was 6.5 ± 1.3 cm. Supraceliac and left renal ischemic times were 22.9 ± 9.3 and 40.6 ± 16.2 minutes, respectively. Six patients (5.6%) died at 30 days. The only predictor of 30-day mortality was decreased preoperative estimated glomerular filtration rate (eGFR) (P = .044 by multivariate analysis; and P = .011 by univariate analysis). One-year and 5-year survival rates were 87% and 50%, respectively. Patients with a history of cerebrovascular disease (P = .001) and postoperative renal insufficiency (P = .034) had increased long-term mortality by log-rank test. Twenty-five (25.3%) patients sustained a postoperative decrease in renal function, while 19 (19.2%) patients had an improvement in renal function. There was no difference in 30-day mortality (5.6% vs 6.0%; P = 1.000), 5-year survival (50% vs 48%; P = .886), major complications (37.0% vs 38.0%; P = 1.000), renal failure (6.1% vs 0%; P = .215), or postoperative change in renal function, in patients undergoing extent IV TAAA repair vs AAA repair with supraceliac clamping but without left renal artery bypass.ConclusionsOpen extent IV TAAA repair can be performed with low morbidity and mortality rates. The performance of left renal artery bypass does not appear to contribute to the morbidity and mortality of extent IV TAAA repair. While decreased preoperative eGFR appears to increase the risk of 30-day mortality, a history of cerebrovascular disease and postoperative renal insufficiency appear to increase the risk of long-term mortality. Finally, open extent IV TAAA repair not uncommonly improves renal function

    Pancreatic tumor pathogenesis reflects the causative genetic lesion.

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    A novel isolator-based system promotes viability of human embryos during laboratory processing

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    In vitro fertilisation (IVF) and related technologies are arguably the most challenging of all cell culture applications. The starting material is a single cell from which one aims to produce an embryo capable of establishing a pregnancy eventually leading to a live birth. Laboratory processing during IVF treatment requires open manipulations of gametes and embryos, which typically involves exposure to ambient conditions. To reduce the risk of cellular stress, we have developed a totally enclosed system of interlinked isolator-based workstations designed to maintain oocytes and embryos in a physiological environment throughout the IVF process. Comparison of clinical and laboratory data before and after the introduction of the new system revealed that significantly more embryos developed to the blastocyst stage in the enclosed isolator-based system compared with conventional open-fronted laminar flow hoods. Moreover, blastocysts produced in the isolator-based system contained significantly more cells and their development was accelerated. Consistent with this, the introduction of the enclosed system was accompanied by a significant increase in the clinical pregnancy rate and in the proportion of embryos implanting following transfer to the uterus. The data indicate that protection from ambient conditions promotes improved development of human embryos. Importantly, we found that it was entirely feasible to conduct all IVF-related procedures in the isolator-based workstations
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