Search results for " transient"
showing 10 items of 191 documents
Reduced Admissions for Cerebrovascular Events during COVID-19 Outbreak in Italy
2020
Supplemental Digital Content is available in the text.
Photodynamics of a Molecular Water-Soluble Nanocluster Identified as Au130(pMBA)50
2015
Photodynamics of a highly monodisperse sample of a water-soluble gold nanocluster tentatively identified as Au130(pMBA)50 (pMBA = p-mercaptobenzoic acid) was studied by mid-IR transient absorption spectroscopy with visible excitation. The observed long-lived excited states (>1 ns) indicate a molecular behavior of the cluster. By combining the transient absorption data with DFT calculation results the observed relaxation dynamics could be fully explained by identifying several relaxation processes involving singlet and triplet manifolds. The results indicate that the cluster may have interesting transient magnetic properties due to a long-lived triplet population.
Deep traps in InGaN/GaN single quantum well structures grown with and without InGaN underlayers
2020
The electrical properties and deep trap spectra were compared for near-UV GaN/InGaN quantum well (QW) structures grown on free-standing GaN substrates. The structures differed by the presence or absence of a thin (110 nm) InGaN layer inserted between the high temperature GaN buffer and the QW region. Capacitance-voltage profiling with monochromatic illumination showed that in the InGaN underlayer (UL), the density of deep traps with optical threshold near 1.5 eV was much higher than in the QW and higher than for structures without InGaN. Irradiation with 5 MeV electrons strongly increased the concentration of these 1.5 eV traps in the QWs, with the increase more pronounced for samples witho…
Experimental test on a fuel cell-supercapacitor hybrid power supply for a digital still camera
2009
Feasibility study of a combi-PV panel for greenhouse energy supply and water recovery by nightly radiation towards the sky
2011
In southern European areas, characterized by high irradiation, the use of water for both evaporative cooling systems and hydroponic fertigation, represents a serious drawback for crop cultivation under cover. Water recovery systems seem to be an attractive solution, especially when they are integrated in the greenhouse construction. In this research, a feasibility study of applying a water recovery system driven by a combi-PV panel, in a semi-closed greenhouse was carried out. The prototype combi-PV panel was made by coupling an amorphous silicon panel with a sump stacked on the rear PV panel surface and filled with saline water. The system is driven by a cold-heat sink which is the PV pane…
Dubái: estrategias para una posible transición urbana
2020
The article presents the work "Dubai Pop-Up. Architecture in a transient city", the result of an international design workshop (coordinated by T. Aglieri Rinella and R. Garcia Rubio) which brought the Dubai question to the center, bringing together a large number of teachers and students to think how to introduce new ways of thinking about the city. Thanks to the diversified and sometimes surprising hypotheses that the projects developed suggest, it is clear how open the degree of alternatives to that development model only oriented on the “monoculture of profit” that has guided urban choices in this city up to now can still be.
Impairment of the modulatory role of nitric oxide on the endothelin-1-elicited contraction of cerebral arteries: a pathogenetic factor in cerebral va…
1997
OBJECTIVE: Nitric oxide (NO) and endothelin-1 (ET-1) are two endothelium-derived factors probably involved in the pathogenesis of cerebral vasospasm after subarachnoid hemorrhage (SAH). Our aim was twofold, i.e., to ascertain whether endothelial and nonendothelial NO modulates the contractile response of cerebral arteries to ET-1 and to analyze whether this relationship might be impaired after experimental SAH. METHODS: Rings of middle cerebral artery from goats in the control group and from goats with SAH were set up for isometric tension recordings. SAH was induced 3 days before the experiments by infusion of 10 ml of autologous arterial blood through a catheter previously inserted into t…
Transient focal cerebral ischemia significantly alters not only EAATs but also VGLUTs expression in rats: relevance of changes in reactive astroglia
2010
The involvement of plasma membrane glutamate transporters (EAATs - excitatory aminoacid transporters) in the pathophysiology of ischemia has been widely studied, but little is known about the role of vesicular glutamate transporters (VGLUTs) in the ischemic process. We analyzed the expression of VGLUT1-3 in the cortex and caudate-putamen of rats subjected to transient middle cerebral artery occlusion. Western blot and immunohistochemistry revealed an increase of VGLUT1 signal in cortex and caudate-putamen until 3 days of reperfusion followed by a reduction 7 days after the ischemic insult. By contrast, VGLUT2 and 3 were drastically reduced. Confocal microscopy revealed an increase in VGLUT2…
A review of psychosocial factors and stroke: A new public health problem
2019
Abstract The role of psychosocial factors (PSF) in increased risk of stroke is a novel public health challenge, but unclear definitions for PSF and the multiple stroke subtypes have led to inconsistent reports. A review of this issue is therefore warranted. Methods Several databases were used for this narrative systematic review (Medline, Embase and Cochrane Library). Two independent reviewers evaluated articles from between 2001 and 2018 on the themes of PSF and stroke/transient ischemic attack (TIA). PSF criteria were job strain, psychological interpersonal and behavioral stress, and social deprivation. Ischemic and hemorrhagic stroke and TIA subtypes were also identified. Results Forty-f…
Changes in the adrenergic mechanisms of cerebral arteries after subarachnoid hemorrhage in goats.
1994
We have examined the effects of experimental subarachnoid hemorrhage (SAH), induced by delivering autologous blood into the subarachnoid space, on the adrenergic mechanisms of the goat cerebrovascular bed. To achieve this, the response to noradrenaline was recorded both in vivo, by measuring cerebral blood flow in unanesthetized animals, and in vitro, by recording isometric tension in isolated cerebral arteries. In addition, we checked the function of adrenergic innervation by measuring the tritium efflux evoked by electrical stimulation in cerebral arteries preloaded with [3H]-noradrenaline, and we examined this innervation by using both fluorescent and electron transmission microscopy. Al…