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   79154篇
  免费   5687篇
  国内免费   152篇
医药卫生   84993篇
  2023年   382篇
  2022年   544篇
  2021年   1272篇
  2020年   869篇
  2019年   1315篇
  2018年   1559篇
  2017年   1261篇
  2016年   1335篇
  2015年   1570篇
  2014年   2174篇
  2013年   3569篇
  2012年   5030篇
  2011年   5428篇
  2010年   2970篇
  2009年   2736篇
  2008年   4931篇
  2007年   5243篇
  2006年   5144篇
  2005年   5305篇
  2004年   5070篇
  2003年   4749篇
  2002年   4501篇
  2001年   994篇
  2000年   837篇
  1999年   940篇
  1998年   969篇
  1997年   841篇
  1996年   717篇
  1995年   737篇
  1994年   653篇
  1993年   553篇
  1992年   641篇
  1991年   665篇
  1990年   600篇
  1989年   540篇
  1988年   580篇
  1987年   513篇
  1986年   501篇
  1985年   518篇
  1984年   509篇
  1983年   421篇
  1982年   420篇
  1981年   431篇
  1980年   361篇
  1979年   372篇
  1978年   334篇
  1977年   266篇
  1976年   249篇
  1975年   239篇
  1974年   286篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
101.
102.
103.
104.
PURPOSE: We systematically assessed the efficacy and safety of appetite stimulants in the management of cancer-related anorexia. Literature databases were searched for randomized controlled trials of appetite stimulants in the treatment of cancer anorexia. MATERIALS AND METHODS: Studies were graded according to quality. Fifty-five studies met inclusion criteria. RESULTS: Only two drugs have evidence to support their use for anorexia (progestins and corticosteroids). There is strong evidence against the use of hydrazine sulfate. The outcomes of these trials have been mixed and patient population heterogeneous. CONCLUSION: The optimal dose, time to start, and duration of treatment for many appetite stimulants for cancer anorexia is still unknown. A more systematic approach to research methodology with universal outcome measure and prospective randomized studies are need. Combination regimens are needed but this cannot at the present time be supported by the data presented.  相似文献   
105.
One limitation of averaging individual late component event related potential (ERP) responses is that a single average ERP cannot reflect the variability of responses from epoch to epoch. In this article, we describe a method to quantify this variability and determine if any part of the overall ERP reflects a maximum variance through the use of response variance curves. We then apply this method to one disorder, schizophrenia, in which variability of information processing is hypothesized to underlie aspects of the symptomatology. Response variance curves in a group of unmedicated schizophrenic patients reveal systematic differences, maximal between 190 and 250 ms, compared with those in a group of medicated schizophrenic patients and normal control subjects.  相似文献   
106.
Aim This paper seeks to illumine how families with children and adult members with intellectual disabilities manage to manifest a buoyant and durable capacity over time. It is therefore concerned centrally with the idea of resilience. Method Drawing from diverse theoretical literatures from child development and protection and gerontology, the paper begins with a review of constructions of resilience. In an attempt to assess where there seems to be support for resilience in families, the core of the paper tests empirical evidence about positive experiences of families supporting children and adults with intellectual disabilities against the theoretical literature on resilience. Result and Conclusions The findings are used to suggest conditions under which resilience is produced and maintained, and to identify emergent elements of a psycho‐social model of resilience in families with children and adult members with intellectual disabilities.  相似文献   
107.
Summary DNA flow cytometry was used to examine the effects of five chemotherapeutic agents, vinblastine, cisplatinum, 5-fluorouracil, cyclophosphamide and Adriamycin, on mouse testes. Alterations in the haploid (1C), diploid (2C) and tetraploid (4C) cell compartments were assessed at 11, 29 and 56 days after giving mice a single intraperitoneal injection of each agent. Analysis of the histograms proved to be a rapid and reproducible method of monitoring injury in this animal model. Because this procedure can detect subtle testicular injuries, it is predicted that DNA histograms obtained from fine needle aspirates will gain increasing acceptance in the management of the oligo- and azoospermic patient.  相似文献   
108.
109.
110.
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