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   3227701篇
  免费   265019篇
  国内免费   13497篇
耳鼻咽喉   44400篇
儿科学   96630篇
妇产科学   80890篇
基础医学   517888篇
口腔科学   88654篇
临床医学   287306篇
内科学   564264篇
皮肤病学   86928篇
神经病学   276068篇
特种医学   126855篇
外国民族医学   105篇
外科学   510844篇
综合类   96142篇
现状与发展   23篇
一般理论   2157篇
预防医学   264169篇
眼科学   73710篇
药学   223697篇
  24篇
中国医学   9539篇
肿瘤学   155924篇
  2021年   54628篇
  2020年   34826篇
  2019年   57764篇
  2018年   70266篇
  2017年   53511篇
  2016年   58975篇
  2015年   73463篇
  2014年   107573篇
  2013年   172563篇
  2012年   83184篇
  2011年   81344篇
  2010年   113843篇
  2009年   119185篇
  2008年   69651篇
  2007年   71094篇
  2006年   82732篇
  2005年   78099篇
  2004年   80223篇
  2003年   71431篇
  2002年   61556篇
  2001年   102512篇
  2000年   95459篇
  1999年   95514篇
  1998年   64407篇
  1997年   62402篇
  1996年   60150篇
  1995年   55635篇
  1994年   49624篇
  1993年   46390篇
  1992年   66306篇
  1991年   62641篇
  1990年   59160篇
  1989年   58736篇
  1988年   54178篇
  1987年   52893篇
  1986年   49813篇
  1985年   50253篇
  1984年   45929篇
  1983年   42317篇
  1982年   40525篇
  1981年   38216篇
  1980年   35942篇
  1979年   36891篇
  1978年   33043篇
  1977年   30817篇
  1976年   27615篇
  1975年   26179篇
  1974年   26559篇
  1973年   25227篇
  1972年   23721篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
151.
152.
153.
154.
155.
156.
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   
157.
158.
159.
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   
160.
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