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Transient Relaxation (transient + relaxation)
Selected AbstractsPerformance of thin-film transistors fabricated by sequential lateral solidification crystallization techniquesPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 12 2008M. A. Exarchos Abstract The performance of Excimer Laser Annealed (ELA) Thin-Film Transistors (TFTs), in terms of drain current behaviour in unstressed as well as in DC stressed devices, is presented. The transistors studied were fabricated under different irradiation schemes of a novel Sequential Lateral Solidification (SLS) process. As far as unstressed transistors concerned, drain current transients relaxed through stretched exponential law. Fitting results disclosed that both gate dielectric polarization and carrier recombination mechanisms occurred through transient relaxation. Deep Level Transient Spectroscopy (DLTS) technique was called forth in order to investi- gate the origin of carrier recombination mechanisms. DC hot carrier stress measurements, under "worst ageing condition" regime, were conducted in order to probe degradation mechanisms and device reliability standards. Crystal domain size significantly affects threshold voltage degradation. The latter increases with decreasing crystal domain size, due to increased concentration of protrusions in the polysilicon film. Transconductance degradation also depends on crystal domain size, attributed mainly to bulk polysilicon trap generation. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Thrombin activation of proteinase-activated receptor 1 potentiates the myofilament Ca2+ sensitivity and induces vasoconstriction in porcine pulmonary arteriesBRITISH JOURNAL OF PHARMACOLOGY, Issue 4 2010Jun Maki Background and purpose:, Thrombus formation is commonly associated with pulmonary arterial hypertension (PAH). Thrombin may thus play an important role in the pathogenesis and pathophysiology of PAH. Hence, we investigated the contractile effects of thrombin and its mechanism in pulmonary artery. Experimental approach:, The cytosolic Ca2+ concentrations ([Ca2+]i), 20 kDa myosin light chain (MLC20) phosphorylation and tension development were evaluated using the isolated porcine pulmonary artery. Key results:, Thrombin induced a sustained contraction in endothelium-denuded strips obtained from different sites of a pulmonary artery, ranging from the main pulmonary artery to the intrapulmonary artery. In the presence of endothelium, thrombin induced a transient relaxation. The contractile effect of thrombin was abolished by either a protease inhibitor or a proteinase-activated receptor 1 (PAR1) antagonist, while it was mimicked by PAR1 -activating peptide (PAR1AP), but not PAR4AP. The thrombin-induced contraction was associated with a small elevation of [Ca2+]i and an increase in MLC20 phosphorylation. Thrombin and PAR1AP induced a greater increase in tension for a given [Ca2+]i elevation than that obtained with high K+ -depolarization. They also induced a contraction at a fixed Ca2+ concentration in ,-toxin-permeabilized preparations. Conclusions and implications:, The present study revealed a unique property of the pulmonary artery. In contrast to normal arteries of the systemic circulation, thrombin induces a sustained contraction in the normal pulmonary artery, by activating PAR1 and thereby increasing the sensitivity of the myofilament to Ca2+. This responsiveness of the pulmonary artery to thrombin may therefore contribute to the pathogenesis and pathophysiology of PAH. [source] Landmarks in the understanding and treatment of reflux diseaseJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 2009John Dent Abstract The last 50 years have seen a transformation in the understanding and treatment of reflux disease. The development and wide use of flexible endoscopy and progressively more sophisticated approaches to measurement of pathophysiological factors have been major drivers of advances. The recognition and progressive elucidation of the mechanical events that comprise the transient lower esophageal sphincter relaxation and how they lead to reflux provide a novel and firm foundation for tailoring therapies that act directly to reduce occurrence of reflux episodes, either surgically or pharmacologically. Novel GABAB agonist drugs have been shown to inhibit transient relaxations and are currently being evaluated in clinical trials on patients with reflux disease. Better understanding has extended to recognition of the extraordinarily high prevalence of reflux disease and of the ability of proton pump inhibitor drugs to deliver major benefits to a high proportion of patients with reflux disease. The life of the Gastroenterological Society of Australia has spanned the period of these major advances. A large number of the members of the Society and their associates have contributed substantially to these advances. [source] Review article: from 1906 to 2006 , a century of major evolution of understanding of gastro-oesophageal reflux diseaseALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 9 2006J. DENT Summary Background Our understanding of gastro-oesophageal reflux disease has undergone significant changes over the last century. Aim To trace the rise in understanding of gastro-oesophageal reflux disease and highlight remaining areas of uncertainty. Methods Literature review. Results In 1906, Tileston published his observations on ,peptic ulcer of the oesophagus'. Winkelstein, in 1934, first correlated symptoms of heartburn with acid regurgitation and reflux oesophagitis. In 1946, Allison described hiatus hernia as a causal factor in the development of gastro-oesophageal reflux disease. In 1958, Bernstein and Baker showed a direct relationship between oesophageal acidification and heartburn in patients with gastro-oesophageal reflux disease, irrespective of endoscopic findings, leading to the recognition of non-erosive gastro-oesophageal reflux disease. In the 1980s, continuous recordings of the lower oesophageal sphincter showed that episodes of reflux were related to transient relaxations of lower oesophageal sphincter tone. There is now increasing recognition that gastro-oesophageal reflux disease arises from the interaction of several anatomical and physiological factors. A turning point in the medical treatment of gastro-oesophageal reflux disease came with the introduction of the first proton pump inhibitor, omeprazole, in 1989. Conclusions Future efforts need to identify the multifactorial interactions of gastro-oesophageal junction anatomy and physiology in patients with gastro-oesophageal reflux disease. Increased understanding of the disease will guide development of new therapies. [source] | ||||||||||