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991.
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A glutathione peroxidase(GPX) mimic, 2-selenium bridged β-cyclodextrin(2-SeCD), was synthesized. In order to examine its role and mechanism in treating stroke we chose stroke-prone spontaneously hypertensive rats(SHRsp) as animal model. 56 SHRsps of 8-week olds were randomly divided into several groups: test groups (low, moderate, high dose of 2-SeCD) and control groups(positive and negative). After onset of the stroke, the rats in test groups were orally administrated with different amounts of 2-SeCD, the positive control group with ebselen, and the negative control group with drinking water. The treatment lasted two weeks, followed by observation of the rats for 10 days, meanwhile blood pressure, biochemical parameters of plasma, and the contents of nitric oxide(NO) and malondialdehyde(MDA) in plasma and brain were determined. The results show that there were significant differences in contents of NO and MDA in plasma and brain between the test groups(high, moderate dose of 2-SeCD) and negative control group. The NO contents of the test groups were obviously higher than that of the negative control group (P〈0.01). The MDA contents of the test groups(high, moderate dose of 2-SeCD) were obviously lower than that of the negative control group(P〈0.01). The mechanism of 2-SeCD in treating stroke was discussed, which maybe related to the increase of NO and the decrease of MDA in plasma and brain tissue, but the exact mechanism should be further studied. Moreover, the tendencies of changes in systolic blood pressure, contents of NO and MDA, and other physiological parameters for the test groups were shown to be much better than the corresponding parameters for the positive group(the group with ebselen)(P〈0.05), indicating that the treatment effect of 2-SeCD is better than that of ebselen. 相似文献
994.
995.
ThehydrogenatomtransferreactionNH H-N H,isanimportantreactioninradicalreactionsandthegas-phrasethermatdecompositionofammonia.Therewereseveralstudiesonthisreactioninexperiment]andtheory='3.Inthispaper,wehaveemployedtheunifiedstatisticaltheory'(UST)tos... 相似文献
996.
本文基于一种并行高精度的静动交接面处理方法,采用了SA模型及基于SA的分离涡模拟DES方法,进行了某压气机静动干涉流动的计算.研究表明对本文算例,在微小分离处,如20%到80%叶高处,DES与SA计算出的流动损失相差很小;而在大分离处,如叶根叶顶处,DES结果与SA差别较大,并且DES可更好地描述涡结构.在叶顶处,DES计算出比SA更强的泄漏流动,导致更大的损失.在叶根处,DES计算出了明显的静叶动态尾迹涡脱落现象,这一现象导致了与SA不一样的损失机理,即脱落涡与动叶头部相撞而产生时序效应,从而使计算损失较小.同时,本文研究结果与之前对孤立静叶的研究是相互验证的. 相似文献
997.
998.
在线性规划的单纯形法中,为求初始的可行基有著名的大M法,即惩罚因子法.在通常的运筹学教材中,只说明当M充分大时,大M法是有效的,并没有给出参数M的确切估计值.现给出一个确定的常数M0,并证明当M>M0时,大M法收敛于原问题的最优解. 相似文献
999.
In weak doped photorefractive LiNbO3 crystal, the diffraction efficiency is highly relevant to the writing and reading beam polarizations. In this paper, based on dynamic coupled-wave equations, we theoretically discuss the diffraction efficiency under four writing and reading polarization conditions, then reach the proven conclusion that with o-polarized beams to write and with e-polarized beam to readout, the diffraction is the largest. 相似文献
1000.
A diode-pumped Nd3+:YVO4 emitting at 1342 nm and 671 nm was developed. Low concentration neodymium doped Nd:YVO4 shows excellent stability at 1342 nm. With a type-Ⅱ noncritical phase-matched LBO crystal as the intracavity frequency doubler, 890 mW of 671 nm light was obtained at 11.2 W incident pumping power, the optical-optical conversion efficiency is 7.9%. 相似文献