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排序方式: 共有7107条查询结果,搜索用时 109 毫秒
1.
Ahmed Imrul Mosaddek Nadira Umme Aktari Cao Fangbin He Xiaoyan Zhang Guoping Wu Feibo 《Planta》2016,243(4):973-985
Planta - The drought-stimulated gene expression of NCED, SUS, and KS - DHN and ABA signal cross-talk with other phytohormones maintains barley root growth under drought stress at pH 4.0 plus... 相似文献
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目的对virB2基因编码蛋白进行分析,为virB2基因及其编码蛋白功能提供实验依据。方法利用多种生物学软件以及网站对VirB2蛋白的结构和功能进行分析预测,VirB2蛋白序列通过基因推导获得并由生物公司合成,然后通过免疫动物实验制备鼠抗VirB2蛋白多克隆抗体,同时设计进行VirB2蛋白细胞毒试验(MTT法)。结果virB2基因编码蛋白属于疏水性蛋白,为鞭毛样结构,有较强的细胞毒作用。结论对VirB2蛋白的结构和功能进行了分析预测,证明VirB2蛋白在H.pylori相关的致病性特别是引起胃黏膜炎症方面起到一定的作用,能够为研究H.pylori致病机制提供帮助。 相似文献
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A novel approach is reported for the development of fluorogenic esterase reporters using alpha-cyano-containing esters as substrates. After ester hydrolysis, the released alcohol, a cyanohydrin, rapidly eliminates HCN to yield the corresponding aldehyde resulting in strong fluorescence. The pi conjugation of the resulting aldehyde also greatly enhances UV absorption and red shifts fluorescence emission relative to a corresponding alcohol or phenol. Two substrates, R/S-acetic acid cyano-(6-methoxynaphthalen-2-yl)-methyl ester (compound I) and trans/cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylic acid R/S-cyano-(6-methoxynaphthalen-2-yl)-methyl ester (compound II), were synthesized and evaluated as substrates. Such alpha-cyano substrates possess very low background fluorescence and are more stable under enzyme assay conditions than phenolic substrates due to the aliphatic cyano group. The higher molar absorbtivity and quantum yield of the aldehyde, along with its larger Stokes' shift combined with the increased stability and lower background signal of the cyanohydrin substrate, increases the utility and sensitivity of the resulting assays over current methods. Moreover, compound II showed high selectivity to pyrethroid-cleaving esterases and may provide a direct tool to monitor pyrethroid resistance in insects. 相似文献
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Nerve growth factor and neuronal cell death 总被引:4,自引:0,他引:4
J. Regino Perez-Polo Perry J. Foreman George R. Jackson Din-e Shan Giulio Taglialatela Larry W. Thorpe Karin Werrbach-Perez 《Molecular neurobiology》1990,4(1-2):57-91
The regulation of neuronal cell death by the neuronotrophic factor, nerve growth factor (NGF), has been described during neural development and following injury to the nervous system. Also, reduced NGF activity has been reported for the aged NGF-responsive neurons of the sympathetic nervous system and cholinergic regions of the central nervous system (CNS) in aged rodents and man. Although there is some knowledge of the molecular structure of the NGF and its receptor, less is known as to the mechanism of action of NGF. Here, a possible role for NGF in the regulation of oxidant--antioxidant balance is discussed as part of a molecular explanation for the known effects of NGF on neuronal survival during development, after injury, and in the aged CNS. 相似文献
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Daniel R. Vlock Beth Arnold Jeannette Humpierres Donald R. Schwartz Shan R. Baker Charles J. Krause Neil Swanson Thomas E. Carey 《Cancer immunology, immunotherapy : CII》1992,34(5):329-336
Summary In previous studies we evaluated the incidence and specificity of autologous antibody reactivity against squamous cell carcinoma of the head and neck (SCCHN). We were able to demonstrate that autologous antibody reactivity is present in native sera but was usually of too low a titer to allow further analysis. Dissociation of immune complexes by acidification and ultrafiltration of serum augmented autologous antibody reactivity in nine out of nine autologous systems tested. Native antibody and antibody derived from immune complexes produced by the host and reactive with autologous tumor cells may be directed against physiologically relevant antigens. Therefore, correlations of antibody titers with clinical course may provide insight into the nature of the host response to cancer. In the present analysis, serological studies of six patients with SCCHN were performed with serum samples obtained over many months. Results of serial serological assays were correlated to tumor progression and clinical course. Fluctuations in autologous antibody reactivity were noted over time. In four cases, rises in autologous antibody titers preceded the clinical diagnosis of recurrence by several months. Drops in autologous antibody reactivity were noted in two cases following surgery or radiation therapy. In two cases of long-term survivors, no correlation between antibody reactivity and clinical course was noted. Specificity analysis of the six autologous systems demonstrated reactivity against autologous and allogeneic SCCHN as well as melanoma cell lines. These sera did not react with glioma, neuroblastoma, renal cell, breast, bladder and colon carcinoma cell lines nor with fetal calf serum, pooled lymphocytes, red blood cells and platelets. Autologous serial serological studies may provide a means by which to evaluate the host/tumor relationship in patients with SCCHN. 相似文献
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冲击波负压对大鼠肺致伤效应的初步观察 总被引:5,自引:0,他引:5
观察了不同的冲击波负压峰值对大鼠肺的影响。各种条件下的冲击波负压值可由负压发生装置来模拟调节,这种装置可满足化爆、核爆和爆炸性减压下负压参数的一般要求,参数稳定,重复性好。冲击波负压峰值范围为-13~-90kPa,下降时间为1~90ms,持续时间为14~2 000ms。6组Wistar系大鼠,分别暴露在-47.2~-84.0kPa的冲击波负压环境中,伤后立即解剖动物,重点观察肺伤情。实验结果显示,在上述冲击波负压环境中,肺可出现从无伤至极重度伤;出血、充血以及肺表面压痕酷似肺冲击伤的病理表现。随着冲击波负压峰值的变化,各组肺伤情亦随着变化,冲击波负压峰值(△P)和减压倍数(P_i/P_a)分别与肺出血面积和动物死亡率相关显著或非常显著。本实验提示,一定条件下的冲击波负压具有明显的致伤作用,且伤情变化范围与超压所致肺伤情变化范围相同,超压和冲击波负压在一定条件下可通过伤情指标等效。 相似文献
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A determinant of polyomavirus virulence enhances virus growth in cells of renal origin. 总被引:3,自引:2,他引:1
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J B Bolen S E Fisher K Chowdhury T C Shan J E Williams C J Dawe M A Israel 《Journal of virology》1985,53(1):335-339
We have identified a strain of polyomavirus, Py(L), which is unusual in causing acute morbidity and early death after inoculation of newborn mice. We determined that these animals died of kidney failure associated with extensive, virus-mediated destruction of renal tissue. Interestingly, the Py(L) strain infects baby mouse kidney cell cultures more efficiently than do other strains. 相似文献
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