首页 | 官方网站   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   3426篇
  免费   474篇
  国内免费   2篇
医药卫生   3902篇
  2021年   55篇
  2020年   41篇
  2019年   59篇
  2018年   52篇
  2017年   47篇
  2016年   54篇
  2015年   48篇
  2014年   72篇
  2013年   96篇
  2012年   172篇
  2011年   108篇
  2010年   96篇
  2009年   70篇
  2008年   165篇
  2007年   135篇
  2006年   156篇
  2005年   188篇
  2004年   163篇
  2003年   129篇
  2002年   140篇
  2001年   115篇
  2000年   138篇
  1999年   124篇
  1998年   44篇
  1997年   37篇
  1996年   50篇
  1995年   45篇
  1994年   43篇
  1993年   41篇
  1992年   88篇
  1991年   80篇
  1990年   85篇
  1989年   68篇
  1988年   88篇
  1987年   84篇
  1986年   68篇
  1985年   71篇
  1984年   62篇
  1983年   58篇
  1982年   26篇
  1981年   25篇
  1980年   19篇
  1979年   34篇
  1978年   36篇
  1977年   23篇
  1974年   21篇
  1973年   27篇
  1972年   26篇
  1971年   16篇
  1970年   30篇
排序方式: 共有3902条查询结果,搜索用时 15 毫秒
1.
2.
Journal of Thrombosis and Thrombolysis - Over the last few years data from our group have indicated that α-synuclein is important in development of immune cells as well as potentially...  相似文献   
3.
4.
Wound healing involves a number of cellular and molecular events, many of which are controlled by soluble growth factors. In the process of healing, hepatocyte growth factor, a cytokine known to act as mitogen, motogen, and morphogen, has been postulated to play multiple roles during several stages of this complex biological process. Produced primarily by stromal fibroblasts, hepatocyte growth factor regulates angiogenesis, vascular permeability, cell migration, matrix deposition and degradation, and other biological processes. The current article discusses recent progress in understanding the multiple roles played by this growth factor in tissue repair.  相似文献   
5.
6.
7.
The object of this enquiry was to obtain some idea of the mortality of untreated sleeping sickness in two non-adjacent districts in Northern Nigeria. The method employed was to obtain data, by methodical questioning of every householder, from which the crude death and other rates could be calculated over a preceding period, and be correlated with the known incidence of sleeping sickness. The figures were worked out village by village, and the villages then combined into groups of sufficient size to make the numbers significant.In the first district, Igabi, a close correlation was obtained, the death rate rising from 71.4 per 1,000 with a sleeping sickness incidence of 18.6 per cent., to 104 per 1,000 with a sleeping sickness incidence of 28.6 per cent. In other words an additional death occurred for approximately every additional three people infected. The infantile mortality rate also showed a close correlation with the sleeping sickness incidence. As infants were not found to be infected, this result was unexpected. The reasons for it are discussed. The birth rate showed no definite correlation.In the second district, Kankara, no correlation was found to exist, and the conclusion is drawn that, during the period under review, sleeping sickness was not fatal; the patients must either have harboured a mild chronic infection carrying no threat to life, or have been undergoing spontaneous cure.The clinical types of the cases found are described. They are similar in the two districts, and would not have been suspected of having so different a prognosis.It is pointed out that Igabi lies in the middle of a sleeping sickness belt, and it is suggested that the virulence of the disease in this district may be accounted for by the very free means of communication which exist, and by the movement in the past of large gangs of labour, tending to disseminate many different strains of trypanosome imported from outside. The infection in Kankara, on the other hand, was probably of later, though not very recent, introduction; and as the district is situated on the very edge of the belt and is traversed by no main roads or railways, the possibility of a multiplicity of strains existing is very much less. If this conclusion is correct, it emphasizes the necessity of careful sleeping sickness control measures in areas which may be opened up in the future.The mean birth rate found in Igabi was 64.7 per 1,000; and the mean death rate 84.2. The corresponding figures for Kankara were 44.1 and 23.6. The reliability of these figures is discussed.  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-23

京公网安备 11010802026262号