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   268篇
  免费   31篇
  国内免费   1篇
  300篇
  2022年   4篇
  2021年   6篇
  2019年   6篇
  2018年   11篇
  2017年   3篇
  2015年   8篇
  2014年   7篇
  2013年   8篇
  2012年   14篇
  2011年   18篇
  2010年   8篇
  2009年   11篇
  2008年   15篇
  2007年   9篇
  2006年   8篇
  2005年   6篇
  2004年   19篇
  2003年   14篇
  2002年   5篇
  2001年   11篇
  2000年   5篇
  1999年   7篇
  1998年   12篇
  1997年   2篇
  1996年   5篇
  1995年   11篇
  1994年   7篇
  1993年   3篇
  1992年   5篇
  1991年   1篇
  1990年   2篇
  1989年   6篇
  1988年   5篇
  1987年   4篇
  1986年   4篇
  1985年   3篇
  1984年   1篇
  1983年   4篇
  1982年   2篇
  1981年   1篇
  1980年   3篇
  1979年   2篇
  1977年   3篇
  1976年   1篇
  1974年   1篇
  1973年   1篇
  1942年   1篇
  1883年   1篇
  1882年   1篇
  1880年   2篇
排序方式: 共有300条查询结果,搜索用时 15 毫秒
1.
2.
The organization of the nervous system ofProcerodes littoralis (Tricladida, Maricola, Procerodidae) was studied by immunocytochemistry, using antibodies to authentic flatworm neuropeptide F (NPF) (Moniezia expansa). Compared to earlier investigations of the neuroanatomy of tricladid flatworms, the pattern of NPF immunoreactivity inProcerodes littoralis reveals differences in the following respects: 1. Shape and structure of the brain. 2. Number and composition of longitudinal nerve cords. 3. Shape of branches of, and transverse connections between, main ventral nerve cords. 4. Composition of the pharyngeal nervous system. The rich innervation by NPF immunoreactive (IR) fibres and cells of the subepithelial muscle layer, the pharynx musculature and the musculature of the male copulatory apparatus indicates a neurotransmitter or neuromodulatory influence on muscular activity.  相似文献   
3.
4.
Porphyrins and corrins have been immobilized onto solid-phase supports and used to dehalogenate organohalides under reducing conditions. One such system has been used to dehalogenate an aqueous solution (10 ppm) of lindane for over 90 days at over 98% efficiency and for a further 150 days in excess of 65% efficiency. Dichloromethane has been shown to be effectively dehalogenated when supplied to immobilized systems in gaseous form. Correspondence to: T. S. Marks  相似文献   
5.
Summary A lambda transducing phage carrying the traGSTD genes of the E. coli K12 sex factor F was isolated by an in vivo technique, and characterized in ra complementation tests, by determining its restriction endonuclease fragment sizes, and by measuring heteroduplex molecules. The size and location on the F physical map of the tra transducing segment was thereby determined.Comparison of the proteins synthesized in UV-irradiated cells by this phage and by a derivative carrying the amber traG79 mutation, allowed the traG product to be identified as a protein of molecular weight 100,000. In the same experiments, the sizes of the traT and traD products made by the phage were also measured, being 25,000 and 85,000 daltons respectively.  相似文献   
6.
7.
The aim of this research was to determine whether all memory T cells have the same propensity to migrate to the joint in patients with juvenile idiopathic arthritis. Paired synovial fluid and peripheral blood mononuclear cell proliferative responses to a panel of antigens were measured and the results correlated with a detailed set of laboratory and clinical data from 39 patients with juvenile idiopathic arthritis. Two distinct patterns of proliferative response were found in the majority of patients: a diverse pattern, in which synovial fluid responses were greater than peripheral blood responses for all antigens tested; and a restricted pattern, in which peripheral blood responses to some antigens were more vigorous than those in the synovial fluid compartment. The diverse pattern was generally found in patients with a high acute phase response, whereas patients without elevated acute phase proteins were more likely to demonstrate a restricted pattern. We propose that an association between the synovial fluid T cell repertoire and the acute phase response suggests that proinflammatory cytokines may influence recruitment of memory T cells to an inflammatory site, independent of their antigen specificity. Additionally, increased responses to enteric bacteria and the presence of αEβ7 T cells in synovial fluid may reflect accumulation of gut associated T cells in the synovial compartment, even in the absence of an elevated acute phase response. This is the first report of an association between the acute phase response and the T cell population recruited to an inflammatory site.  相似文献   
8.
9.
10.
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