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   152篇
  免费   8篇
  2015年   5篇
  2014年   4篇
  2012年   2篇
  2011年   4篇
  2010年   6篇
  2009年   6篇
  2008年   2篇
  2007年   2篇
  2006年   4篇
  2005年   2篇
  2004年   4篇
  2003年   5篇
  2002年   2篇
  2001年   3篇
  2000年   2篇
  1998年   8篇
  1997年   3篇
  1996年   4篇
  1995年   4篇
  1994年   3篇
  1993年   2篇
  1992年   2篇
  1991年   2篇
  1989年   2篇
  1985年   5篇
  1983年   2篇
  1982年   3篇
  1981年   2篇
  1979年   2篇
  1977年   2篇
  1976年   2篇
  1975年   3篇
  1974年   7篇
  1973年   5篇
  1972年   3篇
  1971年   2篇
  1970年   5篇
  1969年   7篇
  1965年   1篇
  1964年   1篇
  1963年   2篇
  1962年   1篇
  1955年   2篇
  1954年   1篇
  1942年   1篇
  1935年   2篇
  1934年   1篇
  1933年   1篇
  1922年   1篇
  1920年   1篇
排序方式: 共有160条查询结果,搜索用时 328 毫秒
1.
2.
3.
The frequency of DNA polymorphisms in the tyrosine kinase domain (exons 17–21) of the insulin receptor gene was assessed in 30 black and 30 white South Africans, using single-stranded conformation polymorphism and direct sequencing analysis. A comparison of the frequencies of the normal versus the combined polymorphic alleles, found only in exon 17, showed a significant difference between black and white groups (P = 0.037). Received: 25 May 1995 / Revised: 1 September 1995  相似文献   
4.
The 5-HT (serotonin) distribution in the nervous system of the macrodasyoid gastrotrich Turbanella cornuta was studied using immunocytochemical methods. Positive immunoreaction was found in two pairs of neurons. The neurons of one pair had processes which extended peripherally to the surface of the body. Central processes of both pairs entered the brain commissure and proceeded into the longitudinal cords. Unlike other acoelomate worms studied so far, the Platyhelminthes and the Nematoda, in this gastrotrich no 5-HT positive perikarya or processes were present in the pharynx innervation, and no positive neurons sent processes directly to the nerve cords  相似文献   
5.
The pituitary responses to the intravenous administration of 200 mg of Thyrotropin Releasing Hormone were investigated in 14 poorly controlled insulin dependent diabetic males and in nine matched controls. The mean TSH and prolactin responses in the two groups were similar although both tended to be lower in the diabetics. There was a small FSH rise in 11 of the 23 subjects.  相似文献   
6.
7.
Meridianins are brominated 3-(2-aminopyrimidine)-indoles which are purified from Aplidium meridianum, an Ascidian from the South Atlantic (South Georgia Islands). We here show that meridianins inhibit various protein kinases such as cyclin-dependent kinases, glycogen synthase kinase-3, cyclic nucleotide-dependent kinases and casein kinase 1. Meridianins prevent cell proliferation and induce apoptosis, a demonstration of their ability to enter cells and to interfere with the activity of kinases important for cell division and cell death. These results suggest that meridianins constitute a promising scaffold from which more potent and selective protein kinase inhibitors could be designed.  相似文献   
8.
The compliance score in randomized trials is a measure of the effect of randomization on treatment received. It is in principle a group-level pretreatment variable and so can be used where individual-level measures of treatment received can produce misleading inferences. The interpretation of models with the compliance score as a regressor of interest depends on the link function. Using the identity link can lead to valid inference about the effects of treatment received even in the presence of nonrandom noncompliance; such inference is more problematic for nonlinear links. We illustrate these points with data from two randomized trials.  相似文献   
9.
10.
Joffe  Boris I.  Kornakova  Elena E. 《Hydrobiologia》1998,383(1-3):245-250
Notentera ivanovi is a parasitic platyhelminth found in the gut of a polychaete, Nephthys ciliata. N. ivanovi has no mouth, pharynx, or intestine; the dorsal epidermis of adult animals forms a thick pad which is very similar to gut epithelia even at the light microscopic level. Structure of ciliary rootlets and dermal glands with peculiar striated secretion bodies point to close relationships with the Fecampiidae, though other important characters imply placing the genus Notentera in a separate family. In mature sperm of N. ivanovi, the axonemes are fully incorporated; they are directed from proximal to distal, as in the Neodermata. We argue that new family, Notenteridae, should be included in the taxon Fecampiida. We also suggest that all Plathelminthes with neodermatan type of spermiogenesis (Fecampiidae, Urastomidae, and Neodermata) form a monophyletic branch within the Plathelminthes Neoophora. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
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