1,910 research outputs found
Apoptosis en las enfermedades cardiovasculares
Apoptosis consists of a distinct form of cell death that displays characteristic alterations in cell morphology and
cell fate which are different than death due to oncosis or necrosis. In terms of tissue kinetics, apoptosis may be considered a mechanism that counterbalances the effect
of cell proliferation by mitotic division. In fact, deregulated apoptosis has been implicated in the development a wide
variety of human diseases. Excessive apoptotic cell death may cause organ atrophy and organ failure. On the other
hand, insufficient elimination of redundant cells may lead to organ and tissue structural remodeling. In recent years,
apoptosis has become a highly fashionable and competitive area of research. Fortunately, it has not escaped the
attention of the cardiovascular community. Sightings of apoptosis have been reported from every corner of cardiovascular
medicine ranging from conduction system defects to congestive heart failure, and from atherosclerosis to aneurysms. There is no question that these sightings will eventually be converted into mechanistic etiopathogenic and physiopathological insights and will form the basis for designing new diagnostic modalities and novel therapies
Review of the molecular pharmacology of Losartan and its possible relevance to stroke prevention in patients with hypertension
BACKGROUND: The Losartan Intervention For End-point reduction in hypertension (LIFE) study found that a losartan-based regimen, compared with an atenolol-based regimen, resulted in a significantly lower risk of stroke in hypertensive patients with left ventricular hypertrophy, despite similar reductions in blood pressure.
OBJECTIVE: The purpose of this review was to examine the molecular and pharmacologic mechanisms that may be associated with the different outcomes observed in the LIFE study.
METHODS: A PubMed/MEDLINE search of English-language articles (1990 to February 2006) with the terms angiotensin II antagonists or AIIAs or angiotensin receptor blockers or losartan or atenolol or beta blocker and terms including, but not limited to, atherosclerosis, left ventricular hypertrophy, carotid artery hypertrophy, fatty streaks, atrial fibrillation, arrhythmias, endothelial function, myocyte hypertrophy, myocardial fibrosis, platelet aggregation, tissue factor, plasminogen activator inhibitor-1, PAI-1, anti-inflammatory, uric acid, or oxidative stress.
RESULTS: Losartan's significant effect on stroke may be related to several possible mechanisms that are independent of blood-pressure reductions. These include improvements in endothelial function and vascular structure; decreases in vascular oxidative stress; reductions in left ventricular hypertrophy, reductions in myocardial fibrosis, or both; and modulation of atherosclerotic disease progression. Although some of these effects may be shared by other angiotensin II receptor antagonists (AIIAs), and perhaps other anti-hypertensive classes (eg, angiotensin-converting enzyme inhibitors), the ability of losartan to lower serum uric acid levels-a proposed independent risk factor for cardiovascular disease-appears to be a molecule-specific effect. Alternative explanations of the results of the LIFE study have also been hypothesized, including inappropriate choice of atenolol as an active comparator and differences in central pulse pressures between study groups.
CONCLUSIONS: This review of the literature suggests that losartan (and perhaps other AIIAs) may possess a number of properties, independent of its antihypertensive effects, that may be associated with decreased vulnerability of the plaque, myocardium, and blood
Understanding extreme Spanish coastal flood events
The Santa Irene flood event, at the end of October 1982, is one of the most dramatically widely reported flood events in Spain. Its renown is mainly due to the collapse of the Tous dam, but its main message is to be the paradigm of the incidence of the maritime/littoral weather and its temporal sea level rise by storm surge accompanying rain process on the coastal plains inland floods. Looking at damages the presentation analyzes the adapted measures from the point of view of the aims of the FP7 SMARTeST Project related to the Flood Resilience improvement in urban areas through looking for Technologies, Systems and Tools an appropriate "road to de market"
Coastal floods and decadal changes: the climate factor
Observation has widely shown for nearly all last century that the Spanish (Dynamic) Maritime Climate was following around 10 to 11 year cycles in its most significant figure, wind wave, despite it being better to register cycles of 20 to 22 years, in analogical way with the semi-diurnal and diurnal cycles of Cantabrian tides. Those cycles were soon linked to sun activity and, at the end of the century, the latter was related to the Solar System evolution. We know now that waves and storm surges are coupled and that (Dynamic) Maritime Climate forms part of a more complex “Thermal Machine” including Hydrological cycle. The analysis of coastal floods could so facilitate the extension of that experience. According to their immediate cause, simple flood are usually sorted out into flash, pluvial, fluvial, groundwater and coastal types, considering the last as caused by sea waters. But the fact is that most of coastal floods are the result of the concomitance of several former simple types. Actually, the several Southeastern Mediterranean coastal flood events show to be the result of the superposition within the coastal zone of flash, fluvial, pluvial and groundwater flood types under boundary condition imposed by the concomitant storm sea level rise. This work shall be regarded as an attempt to clarify that cyclic experience, through an in-depth review of a past flood events in Valencia (Turia and Júcar basins), as in Murcia (Segura’s) as well
Micro Electro Kinetic Actuator (MEKA) arrays for active sublayer control of turbulent boundary layers
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77296/1/AIAA-2002-267-217.pd
Drops with non-circular footprints
In this paper we study the morphology of drops formed on partially wetting
substrates, whose footprint is not circular. This type of drops is a
consequence of the breakup processes occurring in thin films when anisotropic
contact line motions take place. The anisotropy is basically due to hysteresis
effects of the contact angle since some parts of the contact line are wetting,
while others are dewetting. Here, we obtain a peculiar drop shape from the
rupture of a long liquid filament sitting on a solid substrate, and analyze its
shape and contact angles by means of goniometric and refractive techniques. We
also find a non--trivial steady state solution for the drop shape within the
long wave approximation (lubrication theory), and compare most of its features
with experimental data. This solution is presented both in Cartesian and polar
coordinates, whose constants must be determined by a certain group of measured
parameters. Besides, we obtain the dynamics of the drop generation from
numerical simulations of the full Navier--Stokes equation, where we emulate the
hysteretic effects with an appropriate spatial distribution of the static
contact angle over the substrate
Distortions associated with random sea simulators
[EN] Some numerical techniques for simulating Gaussian ergodic stochastic sea models are described, analyzed, and contrasted. A general method for generating all numerical, linear, one¿dimensional simulators by wave superposition permits one to describe or create any of these numerical random sea simulators in five steps. The distortions associated with each numerical simulator by wave superposition are analyzed from a general point of view and the arbitrariness of some numerical simulation techniques commonly used is noted. The time¿consumed in these Monte Carlo experiments is an important factor. The numerical algorithms used can change indirectly the level of distortions associated with each numerical simulation technique. A special reference has been made to the use of the fast Fourier transform (FFT) for computing and to the second¿order autoregressive behavior of each wave component in order to reduce the time¿consumed. Three criteria are proposed for qualifying the numerical simulators in order to adapt the requirements of each numerical experiment considered. To explain the variability of random sea, the deterministic amplitude component simulators are rejected while a nondeterministic spectral amplitude simulator (NSA) using a FFT algorithm can be employed.Medina, JR.; Aguilar Herrando, J.; Diez, JJ. (1985). Distortions associated with random sea simulators. Journal of Waterway Port Coastal and Ocean Engineering. 111(4):603-627. doi:10.1061/(ASCE)0733-950X(1985)111:4(603)S603627111
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