Synthesis of glucoside compounds of ferrocenyl phenols and their antianemic activity

Six glucoside compounds have been synthesized by means of phase-transfer catalytic method and deacetylation from the starting material ferrocene. Their structures have been confirmed by elementary analysis, IR,¹HNMR and MS. The antianemic activities of some compounds have also been tested. Results indicate that these glucoside compounds possess the antianemic activities and therefore, the further study is well worth making. Supported by the foundation of Wuhan Metropolis Commission of Science and Technology Liu Huiying: born in 1937, Professor     

Induction of autotomy in the American bird grasshopperSchistocerca americana (Drury) by the ecdysone agonist RH-5849 and investigation of its mode of action

The non-steroidal ecdysone agonist RH-5849 (1,2-dibenzoyl-l-tert-butylhydrazine) was found to be an effective neurotoxicant on injection into the American bird grasshopper,Schistocerca americana (Drury). Treated grasshoppers became immediately hyperactive, followed by loss of coordination, paralysis and eventually death. We also discovered that this compound induced bilateral autotomy of the metathoracic legs during the early stages of intoxication. However, no evidence of ecdysonergic or morphogenetic activities was observed. Synergism studies with neurotoxins of known mode of action suggested that RH-5849 has a mechanism of action similar to that of 4-amino pyridine, which blocks potassium channels.     

Antioxidant survey to assess antagonism to redox stress using a prokaryotic and an eukaryotic system

Using a prokaryote (Escherichia coli) and a metazoa-resembling eukaryote (Ochromonas danica), we surveyed antioxidants which might overcome redox stress imposed by menadione sodium bisulphite (MD) and buthionine sulphoximine (BSO). BSO oxidant stress was evident only inO. danica; MD oxidant stress was evident in both organisms. Glutathione, its precursors, e.g. cysteine, homocysteine, and 2-oxo-4-thiazolidine carboxylic acid, and red blood cells, emerged as prime antioxidants for relieving BSO and MD oxidant stress. BSO and MD oxidant activity and antioxidant-annulling effect inO. danica were judged comparable to those found in animal cells whereas the resultsE. coli were not entirely equivalent. TheO. danica system emerged as a practical, rapid, and useful system for pinpointing oxidant stressors and antioxidants, and shows promise for studies with mammalian systems.     

(−)-Epigallocatechin gallate,a polyphenolic tea antioxidant,inhibits peroxynitritemediated formation of 8-oxodeoxyguanosine and 3-nitrotyrosine

Reaction with peroxynitrite at pH 7.4 and 37°C was found to increase the 8-oxodeoxyguanosine levels in calf thymus DNA 35-38-fold. This oxidation of deoxyguanosine, as well as the peroxynitrite-mediated nitration of tyrosine to 3-nitrotyrosine, was significantly inhibited by ascorbic acid, glutathione and (–)-epigallocatechin gallate, a polyphenolic antioxidant present in tea. For 50% inhibition of the oxidation of deoxyguanosine to 8-oxodeoxyguanosine, 1.1, 7.6 of 0.25 mM ascorbate, glutathione or (–)-epigallocatechin gallate, respectively, was required. For 50% inhibition of tyrosine nitration, the respective concentrations were 1.4, 4.6 or 0.11 mM. Thus, (–)-epigallocatechin gallate is a significantly better inhibitor of both reactions than either ascorbate or glutathione. Reaction of (–)-epigallocatechin gallate with peroxynitrite alone resulted in the formation of a number of products. Ultraviolet spectra of two of these suggest that the tea polyphenol and/or its oxidation products are nitrated by peroxynitrite.     

活载作用下简支梁弯矩包络图的分段原理

在一组活载作用下简支梁的弯矩包络图是一个分段函数的图形．本文提出了它的一般分段理论与建立分段函数的方法．     

一种求解二维扩散方程的分块隐式方法

提出了一种求解二维扩散方程的分块隐式格式。它结合了古典显格式、古典隐式格式和Crank-nicolson格式，该格式具有明显的并行性、很高的精度、很好的稳定性。     

二维非结构三角形网格的非振荡方法

对非结构三角形网络给出了一种非振荡有限体积方法，该方法在最小平方意义下的构造了非振荡重构良好，对二维Burgers方程国标绕流进行了数值计算，得到比较满意的结果．     

甘肃临泽凹凸棒石粘土矿开发应用研究

甘肃临泽凹土矿突出特点是含有植物动物必须和有益的全部19种微量元素．试验研究表明，临泽凹土对发展节水农业、提高农牧产品产量、改善产品品质、增进人类健康等具有重要的现实意义。     

浅议青少年挫折心理分析及疏导

解释了挫折、挫折感的概念,指出了青少年挫折心理的表现,分析了青少年产生挫折心理的原因以及疏导解决的具体方法。