Search results for "Plate"

Acides gras des phospholipides plaquettaires et des lipides plasmatiques chez le rat obése Zucker

1988

AbstractThe purpose of this work was to see whether hyperlipaemia observed in genetically obese Zucker rats (fa/fa) was associated with differences in fatty-acid composition of plasma triacylglycerols, plasma phospholipids and of platelet phospholipids, in comparison with the control lean rats (Fa/-).Results showed that plasma triacylglycerols and phospholipids were increased in obese rats. In triacylglycerols, the amount of saturated and monounsaturated fatty acids was highly increased whereas the amount of the n-6 and n-3 polyunsaturated fatty acids was little modified. In plasma phospholipids, saturated and monounsaturated fatty acids were also increased, as were the n-3 fatty acids (exc…

Microcirculatory Dysfunction Induced by Cigarette Smoking

2000

This review deals with the deleterious effects of cigarette smoking on the microcirculation, both in terms of morphological (i.e., vessel wall injury, capillary loss) and functional aspects. The latter concerns predominantly changes in tissue perfusion and its regulatory mechanisms (i.e., reactive hyperemia, sequestration of blood cells in the microcirculation). The mechanisms of action of cigarette smoking on the microcirculation include compromised endothelial-dependent vasorelaxation, platelet aggregation, endothelial cell dysfunction, and the activation of circulating leukocytes. Through these mechanisms, cigarette smoking elicits the aggregation and adhesion of leukocytes and/or platel…

Implication of eNOS Uncoupling in Cardiovascular Disease

2017

Under physiological conditions, nitric oxide (NO) is produced in the vasculature mainly by the endothelial nitric oxide synthase (eNOS). Endothelial NO relaxes blood vessels, inhibits platelet activity, and protects against atherosclerosis. Under pathological conditions such as hypertension, diabetes, and hypercholesterolemia, eNOS may become uncoupled. Uncoupled eNOS generates superoxide at the expense of NO and contributes substantially to oxidative stress and endothelial dysfunction. Major mechanisms of eNOS uncoupling include deficiency of the eNOS cofactor tetrahydrobiopterin, deficiency of the eNOS substrate L-arginine, and eNOS S-glutathionylation. Reversal of eNOS uncoupling may rep…

Comparison between the Kummer's transformation and Ewald method for the evaluation of the parallel plate Green's functions

2006

In this paper, we present a convergence and efficiency study of two different acceleration techniques for the evaluation of the parallel plate Green's functions. The first technique is based on the extraction of the asymptotic terms of the spectral representation of the parallel plate Green's functions by applying the Kummer's transformation. The second technique is a straightforward reformulation of the 2-D Green's functions for 1-D periodic structures to the parallel plate case. The PPW Green's functions calculated by the two methods have been successfully applied to the analysis of a practical inductive microwave filter containing metallic and dielectric posts. The filter analysis techni…

Acetylcholine At Motor Nerves: Storage, Release, and Presynaptic Modulati On By Autoreceptors and Adrenoceptors

1992

Publisher Summary This chapter focuses on the modulation of acetylcholine release from the motor endplate by presynaptic receptors. An individual neuron can regulate its function, the release of transmitters or modulators, through the activation of local feedback loops. After escaping the neuronal membrane and entering the synaptic cleft (or extracellular space), the transmitter activates both the receptors localized at the endorgan (postsynaptic receptors) and the receptors localized at the nerve terminal within its diffusion radius (so-called presynaptic or neuronal receptors). Stimulation of presynaptic receptors triggers the generation of intracellular signals that modify ion channels o…

Calixarenes as Stoppers in Rotaxanes

1998

The synthesis of the amide-based rotaxane 7a bearing calix[4]arene blocking groups is described for the first time. While rotaxane formation fails if a calix[4]arene is functionalized at the upper rim with only an amino or methylamino group lacking any spacer, the prolonged amine 5a works successfully as stopper unit preventing dethreading of the dimeric wheel 1a by its size. Rotaxane formation of 8b was observed only by MALDI-TOF mass spectrometry of the reaction mixture of the amine 5b, the axle 6 and 1a. With the larger trimeric wheel 1b no stable rotaxane could be obtained. It either does not act as a concave template or its opening is too wide, even for the bulky calixarene stoppers.

Surfactant controlled preparation of mesostructured transition-metal oxide compounds

1994

The use of surfactants as templates allows the synthesis of mesostructured transition-metal oxides by a cooperative, interface controlled condensation process.

ChemInform Abstract: Desymmetrization Reactions on 4-Pyridone Using Carbohydrate Templates.

2010

Long-term decrease in Asian monsoon rainfall and abrupt climate change events over the past 6,700 years

2021

Significance The variability of the Asian summer monsoon (ASM) is important for the functioning of ecological and societal systems at regional to continental scales, but the long-term evolution and interannual variability of this system is not well understood. Here, we present a stable isotope–based reconstruction of ASM variability covering 4680 BCE to 2011 CE. Superimposed on a gradual drying trend, a rapid drop in mean annual precipitation (>40%) toward persistently drier conditions occurred in ∼1675 BCE. This megadrought caused regional forest deterioration and enhanced aeolian activity affecting Chinese ecosystems. We argue that this abrupt aridification starting ∼2000 BCE triggered wa…

Antithrombotic Therapy in Elderly Patients with Acute Coronary Syndromes

2022

The treatment of acute coronary syndrome (ACS) in elderly patients continues to be a challenge because of the characteS.G.B.ristics of this population and the lack of data and specific recommendations. This review summarizes the current evidence about critical points of oral antithrombotic therapy in elderly patients. To this end, we discuss the peculiarities and differences reported referring to dual antiplatelet therapy (DAPT) in ACS management in elderly patients and what might be the best option considering these population characteristics. Furthermore, we analyze antithrombotic strategies in patients with atrial fibrillation (AF), with a particular focus on those cases that also presen…