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81.
阿胶冲剂与阿胶的化学成分对比分析研究 总被引:2,自引:0,他引:2
阿胶在我国有着悠久的历史,是常用滋补中药,具有许多特殊的功效,国内外享有盛誉。据《本草纲目》及《本草纲目拾遗》等介绍,阿胶在明代以前系用(沙牛)牛,水牛,驴皮或猪、马、驼皮等杂皮熬制而成。自清代始一律采用黑驴皮熬制。以往服用阿胶必须将阿胶先用水浸泡后,然后加热溶解后才能服用.为了克服这一缺点,山东化工学院研制了一种用开水冲服的阿胶新制剂——阿胶冲剂.为了弄清阿胶经物理方法处理后的化学组成成份与原阿谱的化学组成成分的不同变化。我们对其所含微量元素、氨基酸进行了对比分析.另外,本文首次报道了阿胶及阿胶冲剂的红外光谱分析结果. 相似文献
82.
The present study is based on the hypothesis that nonuniform hemodynamics, represented by large time-averaged wall shear stress gradients, trigger abnormal biological processes leading to rapid restenosis, i.e. excessive tissue overgrowth and renewed plaque formation, and hence early graft failure. It implies that this problem may be significantly mitigated by finding graft-artery bypass configurations for which the wall shear stress gradient is approximately zero and hence nearly uniform hemodynamics is achieved. These fluid flow and geometric design considerations are applied to four different end-to-side anastomoses for the distal end of a femoral artery bypass with an appropriate test input pulse and a typical 20–80 flow division. A validated finite-volume code has been used to compute the transient three-dimensional velocity vector fields, wall shear stress distributions and surface contours of the wall shear stress gradients. It is shown that large anastomotic flow areas, small continuously changing bifurcation angles, and smooth junction wall curvatures reduce local time-averaged wall shear stress gradients significantly and hence should mitigate restenosis. 相似文献
83.
Inter- and intraclade neutralization of human immunodeficiency virus type 1: genetic clades do not correspond to neutralization serotypes but partially correspond to gp120 antigenic serotypes. 总被引:22,自引:18,他引:4 下载免费PDF全文
We have studied genetic variation among clades A through E of human immunodeficiency virus type 1 (HIV-1) at the levels of antibody binding to gp120 molecules and virus neutralization. We are unable to identify neutralization serotypes that correspond to the genetic clades. Instead, we observe that inter- and intraclade neutralization of primary isolates by HIV-1-positive sera is generally weak and sporadic; some sera show a reasonable degree of neutralization breadth and potency whereas others are relatively sensitive to neutralization, but no consistent pattern was found. However, a few sera were able to neutralize across clades with significant potency, an observation which may have implications for the feasibility of a broadly effective HIV-1 vaccine involving humoral immunity. Serological assays measuring anti-gp120 antibody binding also failed to identify serotypes that correspond precisely to the genetic clades, but some indications of clade-specific binding were observed, notably with sera from clades B and E. A representative protein for each clade (A through E) was selected on the basis of its specificity, defined as high seroreactivity with sera from individuals infected with virus of that clade and lower reactivity with sera from individuals infected with viruses from other clades. The seroreactivity patterns against these five proteins could be used to predict the genotype of the infecting virus with moderate success. 相似文献
84.
Effect of human immunodeficiency virus type 1 protein R (vpr) gene expression on basic cellular function of fission yeast Schizosaccharomyces pombe. 总被引:7,自引:3,他引:4 下载免费PDF全文
The human immunodeficiency virus type 1 (HIV-1) Vpr protein affects cell morphology and prevents proliferation of human cells by induction of cell cycle G2 arrest. In this study, we used the fission yeast Schizosaccharomyces pombe as a model system to investigate the cellular effects of HIV-1 vpr gene expression. The vpr gene was cloned into an inducible fission yeast gene expression vector and expressed in wild-type S. pombe cells, and using these cells, we were able to demonstrate the specific Vpr-induced effects by induction and suppression of vpr gene expression. Induction of HIV-1 vpr gene expression affected S. pombe at the colonial, cellular, and molecular levels. Specifically, Vpr induced small-colony formation, polymorphic cells, growth delay, and cell cycle G2 arrest. Additionally, Vpr-induced G2 arrest appeared to be independent of cell size and morphological changes. The cell cycle G2 arrest correlated with increased phosphorylation of p34cdc2, suggesting negative regulation of mitosis by HIV-1 Vpr. Treatment of Vpr-induced cell with a protein phosphatase inhibitor, okadaic acid, transiently suppressed cell cycle arrest and morphological changes. This observation implicates possible involvement of protein phosphatase(s) in the effects of Vpr. Together, these data showed that the HIV-1 Vpr-induced cellular changes in S. pombe are similar to those observed in human cells. Therefore, the S. pombe system is suited for further investigation of the HIV-1 vpr gene functions. 相似文献
85.
The interaction between inhibitors of cell division and FtsZ were assessed by using the yeast two-hybrid system. An interaction was observed between FtsZ and SulA, a component of the SOS response, and the interacting regions were mapped to their conserved domains. This interaction was reduced by mutations in sulA and by most mutations in ftsZ that make cell refractory to sulA. No interaction was detected between FtsZ and MinCD, an inhibitory component of the site selection system. However, interactions were observed among various members of the Min system, and MinE was found to reduce the interaction between MinC and MinD. The implications of these findings for cell division are discussed. 相似文献
86.
Osvaldo Giorgi Marzia Orlandi Daniele Lecca Giuliana P. Serra Lei Zhang Maria G. Corda 《Journal of neurochemistry》1996,67(1):423-429
Abstract: The effects of GABA on the kinetics of tert -[35 S]butylbicyclophosphorothionate ([35 S]TBPS) binding to the convulsant site of GABAA receptors were studied in membrane suspensions from the cerebral cortex of newborn (1-day-old) and adult (90-day-old) rats. TBPS dissociation was biphasic in neonates and adults, indicating that more than one interconvertible state of [35 S]TBPS binding sites may be present in the cerebral cortex. In the absence of GABA, the fast ( t 1/2 , 11 min) and slow ( t 1/2 , 77 min) components of TBPS dissociation in newborn rats were approximately fourfold slower than in adults. The acceleration of the dissociation rates caused by 2 µ M GABA, however, was more robust in neonates than in adults (six- to ninefold vs. twofold increase, respectively). Moreover, the dissociation rates of TBPS in membranes preincubated with 2 µ M GABA (dissociation started by adding 40 µ M picrotoxin) were two- to fourfold slower than in membranes preincubated without GABA (dissociation started by adding 40 µ M picrotoxin plus 2 µ M GABA). Taken together, these results suggest that (1) the closed state of GABAA receptors is associated with a more effective steric barrier for the binding of TBPS in neonates compared with adults, (2) GABA produces a larger acceleration of the binding kinetics of TBPS in neonates than in adults, and (3) long incubations with GABA may cause receptor desensitization, which in turn slows down the dissociation rates of TBPS. 相似文献
87.
几种昆虫生长调节剂对家白蚁的毒效试验 总被引:10,自引:2,他引:8
在室内条件下测定了卡死克、抑太保、灭幼豚3号、爱力螨克和扑虱灵五种昆虫生长调节剂对家白蚁的毒杀效果。初步筛选结果表明:卡死克、抑太保和爱力螨克对家白蚁的毒杀效果均较好,家白蚁对爱力螨克尤其敏感。2.30pm。yL爱力螨克、327.36pm0VL、卡死克和369.80V*wL抑太保处理白蚁5~6天后,其死亡率可达100%。忌避性试验表明:卡死克、抑太保和爱力螨克对家白蚁均无明显的驱避作用。 相似文献
88.
中国三瘤蝉属一新种(同翅目:蝉科)雷仲仁,李莉(西北农业大学昆虫研究所陕西杨陵712100)作者在进行中国蝉科较系统的分类研究时,发现三瘤蝉属一新种。模式标本保存在西北农业大学昆虫博物馆(正模)和中国科学院动物研究所(副模)。长度单位为mm。穹三瘤蝉... 相似文献
89.
During periods of water deficit, plants accumulate late embryogenesis-abundant (LEA) proteins which are thought to protect cells from stresses associated with dehydration. One of these genes, le25, is expressed in tomato leaves and roots in response to water deficit and abscisic acid accumulation. To study the function of this protein and to test the effect of overproduction of the LE25 protein in Saccharomyces cerevisiae (Sc), a recombinant plasmid in which le25 is expressed under the control of the GAL1 promoter was constructed. The content of LE25 was high in Sc cells transformed with the recombinant plasmid. The transformant exhibited several stress-tolerant phenotypes. Growth of the transformant in a medium with 1.2 M NaCl was improved, as compared to a control strain. While the control strain showed a long lag phase of 40 h, le25-expressing cells showed a shortened lag phase of 10 h. However, no growth improvement was observed in a medium with 2 M sorbitol. In addition, the transformant had an increased survival rate after freezing stress, but not after high-temperature stress. These results, together with its predicted secondary structure, may indicate that LE25 functions as an ion scavenger. 相似文献
90.
蔷薇属38个野生种果实的维生素含量及其与分组的关系 总被引:6,自引:0,他引:6
对蔷薇属 (Rosa) 38个野生种果实 (以下简称蔷薇果 )的经济性状进行了分析 ,并测定了 VC、VE 和胡萝卜素等重要维生素的含量。蔷薇果 VC 含量在该属种间差异很大 ,以秦岭蔷薇 (R.tsinglingensis)的含量为最高 (2 576mg/ 1 0 0 g) ,德钦蔷薇 (R.deqenensis)的含量为最低 (49mg/ 1 0 0 g)。胡萝卜素含量种间差异明显 ,以软条七蔷薇 (R.henryi)的含量为最高 (1 9.2 4 mg / 1 0 0 g) ,黄刺玫 (R.xanthina)的含量为最低 (0 .0 6 mg/ 1 0 0 g)。 VE 含量种间差异较小 ,在 1 .34 mg/ 1 0 0 g(黄刺玫 )至 3.86 mg/ 1 0 0 g(硕苞蔷薇R.bracteata)之间。对蔷薇亚属 54种野生种果实重要维生素含量的统计分析表明 ,维生素含量与分组具有一定相关性 ,尤以 VC 含量与分组的相关性最为明显 ,桂味组和小叶组 Vc含量很高 (均值都高于 1 80 0mg/ 1 0 0 g) ;合柱组、月季组、木香组和硕苞组含量很低 (均值都在 30 0 mg/ 1 0 0 g以下 ) ,芹叶组除宽刺蔷薇 (R.platyacantha) VC含量很高外 ,其余种类含量都很低 (均值为 1 90 mg/ 1 0 0 g)。胡萝卜素含量与分组也具有一定相关性 ,桂味组、芹叶组、合柱组和硕苞组的胡萝卜素含量较高 ,均值在 6 mg/ 1 0 0 g以上 ;月季组、小叶组和木香组含量较低 ,均值在 0 .4mg/ 1 0 0 g以下。V 相似文献