首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   334篇
  免费   4篇
  2022年   3篇
  2021年   12篇
  2020年   5篇
  2019年   2篇
  2018年   4篇
  2017年   9篇
  2016年   14篇
  2015年   4篇
  2014年   7篇
  2013年   4篇
  2012年   7篇
  2011年   8篇
  2010年   6篇
  2009年   5篇
  2008年   15篇
  2007年   8篇
  2006年   8篇
  2005年   5篇
  2004年   12篇
  2003年   11篇
  2002年   5篇
  2001年   9篇
  2000年   13篇
  1999年   9篇
  1992年   2篇
  1991年   9篇
  1990年   7篇
  1989年   5篇
  1988年   6篇
  1987年   6篇
  1986年   5篇
  1985年   7篇
  1983年   1篇
  1982年   3篇
  1980年   7篇
  1979年   6篇
  1978年   4篇
  1977年   4篇
  1976年   4篇
  1975年   9篇
  1974年   8篇
  1973年   12篇
  1972年   7篇
  1971年   11篇
  1970年   5篇
  1969年   9篇
  1968年   4篇
  1967年   3篇
  1966年   3篇
  1965年   4篇
排序方式: 共有338条查询结果,搜索用时 15 毫秒
91.
General regularities in the structure of the microbial communities of southern taiga soil ecosystems and taxonomic differences between the microbial communities of soils with different hydrothermal characteristics are discussed with reference to the main types of soils of the Central State Forest Biosphere Reserve.  相似文献   
92.
Islet cell autoantigen (ICA) 512 of type I diabetes is a receptor tyrosine phosphatase-like protein associated with the secretory granules of neurons and endocrine cells including insulin-secreting beta-cells of the pancreas. Here we show that in a yeast two-hybrid assay its cytoplasmic domain binds beta2-syntrophin, a modular adapter which in muscle cells interacts with members of the dystrophin family including utrophin, as well as the signaling molecule neuronal nitric oxide synthase (nNOS). The cDNA isolated by two-hybrid screening corresponded to a novel beta2-syntrophin isoform with a predicted molecular mass of 28 kDa. This isoform included the PDZ domain, but not the C-terminal region, which in full-length beta2-syntrophin is responsible for binding dystrophin-related proteins. In vitro binding of the beta2-syntrophin PDZ domain to ICA512 required both ICA512's C-terminal region and an internal polypeptide preceding its tyrosine phosphatase-like domain. Immunomicroscopy and co-immunoprecipitations from insulinoma INS-1 cells confirmed the occurrence of ICA512-beta2-syntrophin complexes in vivo. ICA512 also interacted in vitro with the PDZ domain of nNOS and ICA512-nNOS complexes were co-immunoprecipitated from INS-1 cells. Finally, we show that INS-1 cells, like muscle cells, contain beta2-syntrophin-utrophin oligomers. Thus, we propose that ICA512, through beta2-syntrophin and nNOS, links secretory granules with the actin cytoskeleton and signaling pathways involving nitric oxide.  相似文献   
93.
94.
Bacteria were isolated from the nasopharynx of BALB/c mice and electroporated with pUR290(NS1)2 containing two copies of tick-borne encephalitis virus (TBEV) strain Sofjin NS1 under the control of the lac promoter. The plasmid persisted in transformants for at least ten passages. The NS1 gene expression was detected in Gram-negative enterobacteria via immunoblotting with monoclonal antibodies against TBEV nonstructural glycoprotein NS1. Recombinant NS1 was detected in bacterial cells and in the culture medium. Intranasal immunization with recombinant bacteria activated production of antibodies against NS1 in serum of BALB/c mice. The humoral immune response to NS1 failed to protect immunized mice from a TBEV challenge.  相似文献   
95.
Changes in protoporphyrin conformation, partial pressures of O2 and CO2, and the mechanisms responsible for regulation of pCa and pH in erythrocytes were studied in essential hypertension (EH). Changes in protoporphyrin conformation in EH were accompanied by a decrease in the partial pressure of O2 and an increase in the partial pressure of CO2. This was associated with increased activities of Na+/H+-exchange and Ca2+-dependent K+-channels and with a decreased activity of Ca2+-ATPase. The changes in protoporphyrin conformation in EH are suggested to decrease the efficiency of O2 metabolism in hemoglobin and increase the values of intracellular pCa and pH of erythrocytes.  相似文献   
96.
Neuroimmune interactions in systemic rheumatic diseases were studied. The state of the central nervous system was assessed from the parameters of constant brain potentials, and the state of the immune system, from a complex of immunobiochemical parameters. The highest multiple correlation coefficients were revealed between the immunobiochemical parameters and the parameters of the constant brain potential, which characterize linear and standard deviations of potentials in temporal zones from potentials at other points of recording. The results are discussed in terms of structural and functional integration of the immune and nervous systems.  相似文献   
97.
98.
The data obtained upon examination of patients with systemic rheumatic diseases were analyzed by the methods of multiple regression and step-by-step discriminant analysis. Is was shown that the activity of autoimmune process correlates with the parameters of distribution of constant potential level in the brain of each patient, irrespective of diagnosis. The scatter of potential values was the most important predictor of activity. An increase in the activity of the autoimmune process correlated with a decrease in the scatter of potential values at recording points; the cerebral cortex became equipotential.  相似文献   
99.
The studies demonstrated the immunological and epidemiological effectiveness of a single injection of adsorbed diphtheria-tetanus toxoid with reduced antigen content for adults: intense antidiphtheria immunity in 92.3% of the vaccinees 1-3 months and in 94.5% of the vaccinees 1 year after the injection. This immunity remained sufficiently intense for 3 years (the term of observation). The geometric mean of antitoxic titers was 0.84 I. U./ml. The highest intensity of immunity appearing after the injection was observed in persons aged 18-20 years who showed the highest antitoxic titers (exceeding 0.5 I. U./ml) in 100% of cases, the lowest intensity was registered in the age group of 30-39 years; in 14.2% of these vaccinees antitoxic titers were below the protective level. In other age groups (40-49 years, 50 years and over) the intensity of immunity was high. The geometric mean of the titers of diphtheria antitoxin were 1.2 I. U./ml and 2.1 I. U./ml respectively. In none of the foci under study the spread of the manifest forms of the disease was observed.  相似文献   
100.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号