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   3377215篇
  免费   239973篇
  国内免费   8430篇
耳鼻咽喉   45409篇
儿科学   111033篇
妇产科学   94262篇
基础医学   480033篇
口腔科学   93952篇
临床医学   311391篇
内科学   659256篇
皮肤病学   79063篇
神经病学   276394篇
特种医学   128900篇
外国民族医学   964篇
外科学   496599篇
综合类   69086篇
现状与发展   7篇
一般理论   1449篇
预防医学   266404篇
眼科学   75977篇
药学   246335篇
  12篇
中国医学   6472篇
肿瘤学   182620篇
  2019年   26528篇
  2018年   36878篇
  2017年   28422篇
  2016年   32535篇
  2015年   36908篇
  2014年   50845篇
  2013年   77117篇
  2012年   102564篇
  2011年   108793篇
  2010年   65129篇
  2009年   62634篇
  2008年   102132篇
  2007年   108672篇
  2006年   109909篇
  2005年   105990篇
  2004年   101985篇
  2003年   98292篇
  2002年   95000篇
  2001年   156392篇
  2000年   160050篇
  1999年   135208篇
  1998年   39227篇
  1997年   35015篇
  1996年   35463篇
  1995年   34110篇
  1994年   31459篇
  1993年   29501篇
  1992年   106323篇
  1991年   103193篇
  1990年   99963篇
  1989年   96502篇
  1988年   88991篇
  1987年   87206篇
  1986年   82212篇
  1985年   78350篇
  1984年   58947篇
  1983年   50281篇
  1982年   29990篇
  1981年   26957篇
  1979年   53064篇
  1978年   37979篇
  1977年   32242篇
  1976年   29803篇
  1975年   31914篇
  1974年   38032篇
  1973年   36685篇
  1972年   34536篇
  1971年   32114篇
  1970年   29883篇
  1969年   28522篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
72.
73.
74.
BackgroundThe aim of this paper is to assess the current state of quality and outcomes measures being reported for hepatic resections in the recent literature.MethodsMedline and PubMed databases were searched for English language articles published between 1 January 2002 and 30 April 2013. Two examiners reviewed each article and relevant citations for appropriateness of inclusion, which excluded papers of liver donor hepatic resections, repeat hepatectomies or meta-analyses. Data were extracted and summarized by two examiners for analysis.ResultsFifty-five studies were identified with suitable reporting to assess peri-operative mortality in hepatic resections. In only 35% (19/55) of the studies was the follow-up time explicitly stated, and in 47% (26/55) of studies peri-operative mortality was limited to in-hospital or 30 days. The time period in which complications were captured was not explicitly stated in 19 out of 28 studies. The remaining studies only captured complications within 30 days of the index operation (8/28). There was a paucity of quality literature addressing truly patient-centred outcomes.ConclusionQuality outcomes after a hepatic resection are inconsistently reported in the literature. Quality outcome studies for a hepatectomy should report mortality and morbidity at a minimum of 90 days after surgery.  相似文献   
75.
76.
There are an estimated 56 million orphans and vulnerable children across sub-Saharan Africa. Communities typically care for orphan children through informal caring arrangements – either within or outside of kinship networks. Within Kenya, an estimated 250,000 children live on the streets. There is less research related to fostering attitudes of this special population than orphans and vulnerable children generally. Important research over the past decade has illuminated multiple ways in which children are made more vulnerable because of HIV, including parental death and street-migration from HIV-affected households. As HIV transitions from a terminal illness to a chronic, manageable one, research is also required to establish how parents living with HIV can be an asset to children. In this study, we assess whether mothers living with HIV were very willing to foster biologically-related children, and street-involved children, how these fostering attitudes differed from mothers not living with HIV, and whether differences in fostering attitudes by reported HIV status were mediated by social support, family functioning and general self-rated health. Approximately 40% of mothers living with HIV were very willing to provide long-term foster care to biologically-related or street-involved children. This was less than the percentage of mothers not living with HIV, who were very willing to foster biologically-related children (61%) or street-involved children (58%). Significant portions of these differences were explained by social support, family functioning and general self-rated health. Multi-sectoral approaches are suggested by these findings in order to improve the child-fostering capacity of mothers living with HIV. Improving social support, family functioning and general self-rated health among HIV-infected mothers may not only provide protective benefits for the mothers and their children, but also expand the community’s capacity to care for orphan and vulnerable children.  相似文献   
77.
78.
79.
Objective: Report measured resting energy expenditure (REE) in wheelchair rugby athletes and evaluate agreement between REE and the prediction models of Chun, Cunningham, Harris-Benedict, Mifflin, Nightingale and Gorgey, and Owen.

Design: Cohort-based validation study.

Setting. Paralympic team training camp.

Participants: Fourteen internationally competitive athletes who play wheelchair rugby, 13 of whom had cervical spinal cord injuries (SCI).

Outcome Measures: A portable metabolic analyzer was used to measure REE following an overnight fast and dual-energy X-ray absorptiometry (DXA) was used to assess lean body mass for the prediction equations.

Results: REE in the current sample was 1735?±?257?kcal?×?day?1 ranging from 1324 to 2068?kcal?×?day?1 Bhambhani Y. Physiology of wheelchair racing in athletes with spinal cord injury. Sports Med 2002;32(1):2351.[Crossref], [PubMed], [Web of Science ®] [Google Scholar]. Bland–Altman analyses revealed negative mean bias but similar limits of agreement between measured REE and scores predicted by Chun, Cunningham, Mifflin, Nightingale and Gorgey, and Owen models in elite athletes who play wheelchair rugby.

Conclusion: Prediction models regressed on persons with and without SCI under-predicted REE of competitive wheelchair rugby athletes. This outcome may be explained by the higher REE/fat-free mass (FFM) ratio of current athletes compared to less active samples. Findings from the current study will help practitioners to determine nutrient intake needs on training days of varied intensity.  相似文献   
80.
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