Search results for "Transient"

Postischemic application of lipid peroxidation inhibitor U-101033E reduces neuronal damage after global cerebral ischemia in rats.

1998

Background and Purpose —The lipid peroxidation inhibitor U-101033E was examined for effects on cerebral blood flow (CBF), cortical tissue hemoglobin oxygen saturation (HbS o 2 ), and neuronal damage. Methods —Fifteen minutes of global cerebral ischemia was induced by two-vessel occlusion and hypobaric hypotension. Wistar rats (n=25) were randomized to receive vehicle (n=9) or 40 mg/kg U-101033E (n=9) intraperitoneally during 2 hours of reperfusion. A sham group (n=7) had neither ischemia nor therapy. Histology was evaluated 7 days after ischemia. Results —During late hyperperfusion (at 17 minutes), vehicle-treated animals had a higher ( P =0.044) cortical tissue HbS o 2 (72.0±1.4%) than di…

Neurological complications of Anderson-Fabry disease

2012

Characteristic clinical manifestations of AFD such as acroparesthesias, angiokeratoma, corneal opacity, hypo/ and anhidrosis, gastrointestinal symptoms, renal and cardiac dysfunctions can occur in male and female patients, although heterozygous females with AFD usually seems to be less severely affected. The most prominent CNS manifestations consist of cerebrovascular events such as transient ischaemic attacks (TIAs) and (recurrent) strokes . For the most part, CNS complications in AFD have been attributed to cerebral vasculopathy, including anatomical abnormalities. The natural history of Fabry patients includes transitory cerebral ischaemia and strokes, even in very young persons of both …

Dietary phytoestrogens improve stroke outcome after transient focal cerebral ischemia in rats.

2006

As phytoestrogens are postulated as being neuroprotectants, we assessed the hypothesis that dietary isoflavone-type phytoestrogens are neuroprotective against ischemic stroke. Transient focal cerebral ischemia (90 min) was induced by middle cerebral artery occlusion (MCAO) following the intraluminal thread technique, both in rats fed with soy-based diet and in rats fed with isoflavone-free diet. Cerebro-cortical laser-Doppler flow (cortical perfusion, CP), arterial blood pressure, core temperature, PaO2, PaCO2, pH and glycemia were measured before, during and after MCAO. Neurological examination and infarct volume measurements were carried out 3 days after the ischemic insult. Dietary isofl…

Long‐Term Risk of Myocardial Infarction Compared to Recurrent Stroke After Transient Ischemic Attack and Ischemic Stroke: Systematic Review and Meta‐…

2018

Background Uncertainties remain about the current risk of myocardial infarction ( MI ) after ischemic stroke or transient ischemic attack. Methods and Results We undertook a systematic review to estimate the long‐term risk of MI , compared to recurrent stroke, with temporal trends in ischemic stroke/transient ischemic attack patients. Annual risks and 95% confidence intervals (95% CI ) of MI and recurrent stroke were estimated using random‐effect meta‐analyses. We calculated incidence ratios of MI /recurrent stroke, for fatal and nonfatal events, using similar analyses. Rate ratios for MI in patients with potential risk factors compared to those without were calculated using Poisson regres…

Insights from Experiences on Antiplatelet Drugs in Stroke Prevention: A Review

2020

Reduction of hazard risk of cerebral ischemic event (stroke, transient ischemic attack (TIA)) represents the hard point to be achieved from primary or secondary preventive strategy in the best clinical practice. However, results from clinical trials, recommendations, guidelines, systematic review, expert opinions, and meta-analysis debated on the optimal pharmacotherapy to achieve the objective. Aspirin and a number of antiplatelet agents, alone or in combination, have been considered from large trials focused on stroke prevention. The present review summarizes, discusses results from trials, and focuses on the benefits or disadvantages originating from antiplatelet drugs. Sections of the r…

Unstructural Biology of TRP Ion Channels: The Role of Intrinsically Disordered Regions in Channel Function and Regulation

2021

The first genuine high-resolution single particle cryo-electron microscopy structure of a membrane protein determined was a transient receptor potential (TRP) ion channel, TRPV1, in 2013. This methodical breakthrough opened up a whole new world for structural biology and ion channel aficionados alike. TRP channels capture the imagination due to the sheer endless number of tasks they carry out in all aspects of animal physiology. To date, structures of at least one representative member of each of the six mammalian TRP channel subfamilies as well as of a few non-mammalian families have been determined. These structures were instrumental for a better understanding of TRP channel function and …

A discrete pulse group control-based series resonant inverter with complete ZCS-assisted inductors for consumer high frequency IH application

2017

This paper presents a pulse density modulated (PDM) voltage source high frequency series load resonant soft switching inverter (SRI) for the HF induction heated fixing roller in the energy saving copy and printing machines. The proposed simple and high efficiency SRI based on PDM control operation can achieve complete zero current soft switching for wide output power regulation ranges. In this work, its transient and steady-state operating principle are described and analyzed on the basis of high frequency PDM. The operating performances as power conversion efficiency, power losses analysis and temperature rising characteristics of this SRI are demonstrated and discussed through experimenta…

Transient absorption with a femtosecond tunable excitation pump reveals the emission kinetics of color centers in amorphous silica.

2021

We report a set of femtosecond (fs) transient absorption (TA) measurements following the dynamics of the so-called nonbridging oxygen hole center in silica, a model color center in wide bandgap amorphous solids, characterized by a very large Stokes shift between the UV excitation and its associated red emission at 1.9 eV. The changes in the TA spectrum were probed in the UV-visible range at various delays after photoexcitation and analyzed as a function of the UV excitation energy, in single-photon absorption conditions. The combination of the experiments helps to clarify the defect photocycle, highlighting how TA measurements with tunable UV excitation could represent a powerful tool to in…

Transient drift‐diffusion simulation of the open circuit voltage decay in ionic perovskite solar cells

2021

Reduction of thermal damage in ultrathin gate oxides after intrinsic dielectric breakdown

2001

We have compared the thermal damage in ultrathin gate SiO2 layers of 5.6 and 3 nm thickness after intrinsic dielectric breakdown due to constant voltage Fowler-Nordheim stress. The power dissipated through the metal-oxide-semiconductor capacitor during the breakdown transient, measured with high time resolution, strongly decreases with oxide thickness. This is reflected in a noticeable reduction of the thermal damage found in the structure after breakdown. The effect can be explained as the consequence of the lower amount of defects present in the oxide at the breakdown instant and of the occurrence of a softer breakdown in the initial spot. The present data allow us to estimate the power t…