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41.
Echocardiographic quantification of the severity of anterior mitral leaflet retraction aids prediction of severe mitral regurgitation after balloon valvuloplasty.  相似文献   
42.
Sorcin is a 22 kDa calcium binding protein that is widely distributed in mammalian tissues, including brain, and is associated with the ryanodine receptor (RyR) family of intracellular calcium-release channels in the heart. To determine the cellular sites for potential central functions of sorcin, we examined the electron microscopic immunocytochemical localization of antipeptide antisera against sorcin and against cardiac and brain RyR in the rat caudate-putamen nucleus (CPN), one of the few regions expressing high levels of brain RyR. Sorcin-like immunoreactivity (S-LI) was detected in both neurons and glia by using immunoperoxidase and immunogold methods. Of 1,735 profiles containing immunogold-silver labeling for sorcin, almost 50% were dendrites and many of these dendrites were spiny. The remainder were mainly small axons, axon terminals, and, more rarely, glia. Furthermore, analysis of dually labeled tissue sections showed the presence of sorcin in many of the dendrites and some of the axonal and glial processes containing RyR. In dendrites, gold-silver deposits showing S-LI were prominently localized to saccules of smooth endoplasmic reticulum and mitochondria, both of which are known to store calcium. These labeled structures were located near the plasma membrane at sites postsynaptic to excitatory-type asymmetric junctions, as well as non-synaptic portions of the plasma membrane. In axons, S-LI was also often seen at extrasynaptic sites on, or near, the plasma membrane. We conclude that in the rat CPN, sorcin may act independently or, in conjunction with RyR, to modulate cytoplasmic release of calcium, mainly from smooth endoplasmic reticulum and/or mitochondria in neurons.  相似文献   
43.
In India, an estimated 80% of children are infected with tubercle bacillus by 10 years of age. Elimination of tuberculosis depends on finding all infectious patients and providing them with curative chemotherapy. Pulmonary tuberculosis--the most common form in children--is diagnosed when a child presents with fever, prolonged cough, weight loss, recurrent wheezing, or chest infection; the chest x-ray is suggestive of tuberculosis; and three or more of the following conditions exist: 1) Mantoux test result of 10 mm or more, 2) tuberculosis lymphadenitis by fine needle aspiration cytology, 3) grade III malnutrition, 4) no BCG vaccination, 5) positive family history of tuberculosis, and 6) recent history of pertussis or measles. Recommended, for children with pulmonary tuberculosis, is a regimen of isoniazid, rifampicin, and pyrazinamide daily for 2 months, followed by the first two drugs daily for an additional 4 months. The poor tuberculosis cure rates in most developing countries reflect patient non-compliance with treatment regimens.  相似文献   
44.
Al2O3-Ni interface formed under vacuum condition is non-wetting and weak. Severe instantaneous intedecial reaction (i.e. wetting) at the Al2O3-Ni interface promoted by oxygen can create a strengthened interface. The NiAl2O4 spinel-Ni intedece is weak and growth of the spinel interphase is detrimental to the Al2O3-Ni intedecial bonding. A proper control of the oxygen partial pressure can achieve wetting while avoiding the existence of spinel at the interface, producing stronger interfaces by both mechanical interlocking and more intimate chemical bonding in an Al2O3-20 vol pct Ni composite.  相似文献   
45.
当冷速达10~6K/s量级时,Ni-34.6at-%Al合金中,富Ni的NiAl的微观组织尺寸显著减少,高密度、均匀分布的各类界面阻滞了裂纹的扩展,并在裂纹尖端产生局域塑性变形,室温延性和韧性明显提高  相似文献   
46.
氧饱和煤焦的TPD-MS谱中的CO_2脱附曲线是宽阔带状,在683K附近有一个脱附峰,CO脱附曲线有一个由963K主峰和1083K的肩峰组成的巨大脱附峰及一个在1473K附近的脱附峰。CO_2气化煤焦的TPD—MS谱只有一条CO脱附曲线,在1253和1473K附近突出两个脱附峰。用CO处理的煤焦样品的TPD-MS谱与CO_2气化煤焦样品的TPD-MS谱相似。由此推测仅有两种分别具有半醌型和环醚型结构的碳表面氧化物参与气化反应,并从结构角度解释了煤焦CO_2气化反应的机理。  相似文献   
47.
For technological reasons many high-performance solid rocket motors are made from segmented propellant grains with non-uniform port geometry. In this paper parametric studies have been carried out to examine the geometric dependence of transient flow features in solid rockets with non-uniform ports. Numerical computations have been carried out in an inert simulator of solid propellant rocket motor with the aid of a standard k-ωturbulence model. It was seen that the damping of the temperature fluctuation is faster in solid rocket with convergent port than with divergent port geometry. We inferred that the damping of the flow fluctuations using the port geometry is a meaningful objective for the suppression and control of the instability and/or pressure/thrust oscillations during the starting transient of solid rockets.  相似文献   
48.
We report the cytotoxicity of the ginseng saponin metabolite, Compound K (20‐O‐D‐glucopyranosyl‐20(S)‐protopanaxadiol, IH901) on various human leukemia cell lines. Compound K had the most effect on U937, a human monocytic leukemia cell line among the tested cell lines. Compound K‐treated U937 cells showed characteristics of apoptosis: an exposure of phosphatidylserine from the inner cell membrane to the outer cell membrane, the formation of apoptotic bodies and DNA fragmentation. Compound K induced apoptosis by up‐regulating Bax, disrupting the mitochondrial membrane potential, and by activating caspase 9 and caspase 3. Therefore, we suggest that Compound K inhibits U937 cell growth by inducing apoptosis through the up‐regulation of Bax and caspase activation.  相似文献   
49.
This paper presents an approach which enables surface modelling, mesh generation and the Finite Element (FE) analysis to be integrated together to simulate superplastic forming process for complex shaped components. Techniques have been developed to generate an FE mesh over non-four-sided surface areas, the boundaries of which are Bezier curves of arbitrary degree, using a consistent expression. Theoretical evidence is given to determine the number of Bezier triangular patches required for accurately re-constructing die surfaces within a commercial FE solver. The developed techniques have been successfully used in determining the process parameters for forming a 3D rectangular box.  相似文献   
50.
A COUPLED MORPHODYNAMIC MODEL FOR APPLICATIONS INVOLVING WETTING AND DRYING   总被引:1,自引:0,他引:1  
This work presents a new finite volume Godunov-type model for predicting morphological changes under the rapidly varying flood conditions with wetting and drying.The model solves the coupled shallow water and Exner equations,with the interface fluxes evaluated by an Harten-Lax-van Leer-Contact(HLLC) approximate Riemann solver.Well-balanced solution is achieved using the surface gradient method and wetting and drying are handled by a non-negative reconstruction approach.The new model is validated against several theoretical benchmark tests and promising results are obtained.  相似文献   
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