Search results for " transient"
showing 10 items of 191 documents
Time Trends in Hospital-Referred Stroke and Transient Ischemic Attack: Results of a 7-Year Nationwide Survey in France
2010
<i>Background:</i> Nationwide evaluations of the burden of stroke are scarce. We aimed to evaluate trends in stroke and transient ischemic attack (TIA) hospitalization, in-hospital case fatality rates (CFRs) and mortality rates in France during 2000–2006. <i>Methods:</i> Hospitalizations for stroke and TIA were determined from National Hospital Discharge Diagnosis Records that used the International Classification of Disease, 10th revision, codes I60, I61, I63, I64, G45, G46. CFRs and mortality rates were estimated from the national death certificates database. <i>Results:</i> The total number of stays for stroke increased between 2000 and 2006 (88,371 vs…
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…
From equilibrium to steady state: The transient dynamics of colloidal liquids under shear
2008
We investigate stresses and particle motion during the start up of flow in a colloidal dispersion close to arrest into a glassy state. A combination of molecular dynamics simulation, mode coupling theory and confocal microscopy experiment is used to investigate the origins of the widely observed stress overshoot and (previously not reported) super-diffusive motion in the transient dynamics. A link between the macro-rheological stress versus strain curves and the microscopic particle motion is established. Negative correlations in the transient auto-correlation function of the potential stresses are found responsible for both phenomena, and arise even for homogeneous flows and almost Gaussia…
Intrinsic and extrinsic point-defects in vapor transport grown ZnO bulk crystals
2006
Vapor transport grown ZnO bulk crystals were characterized by electrical, optical and magnetic resonance spectroscopy. The experiments show that the residual carrier concentration is caused by residual H, Al, Ga, and oxygen vacancies in the material. Annealing the samples in O 2 at about 1000 °C (2 atm, 20 h) reduces the H and V O donor concentration by typical one order of magnitude. The photoluminescence and DLTS results suggest a correlation between the broad unstructured emission at 2.45eV (green band) and a donor level 530 meV below the conduction band (E4).
Ab Initio Simulation of Attosecond Transient Absorption Spectroscopy in Two-Dimensional Materials
2018
We extend the first-principles analysis of attosecond transient absorption spectroscopy to two-dimensional materials. As an example of two-dimensional materials, we apply the analysis to monolayer hexagonal boron nitride (h-BN) and compute its transient optical properties under intense few-cycle infrared laser pulses. Nonadiabatic features are observed in the computed transient absorption spectra. To elucidate the microscopic origin of these features, we analyze the electronic structure of h-BN with density functional theory and investigate the dynamics of specific energy bands with a simple two-band model. Finally, we find that laser-induced intraband transitions play a significant role in…
Investigation of recovery mechanisms in dye sensitized solar cells
2016
Abstract We study the spontaneous recovery phenomenon displayed by solar cells sensitized with a ruthenium complex-based dye N719, which manifests with the increase over the time (from several minutes up to some days) of the short circuit current density J sc and the open circuit voltage V oc , during cell illumination. Under dark conditions the current decreases over time after the application of forward bias voltages. We investigate the effects of temperature and electrolyte composition by means of current–voltage measurements and electrochemical impedance spectroscopy, both under dark and illumination conditions. The main result is that the recovery of the performances depends on the cha…