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   4342289篇
  免费   301042篇
  国内免费   10968篇
耳鼻咽喉   61411篇
儿科学   143371篇
妇产科学   121835篇
基础医学   609533篇
口腔科学   127148篇
临床医学   397139篇
内科学   832813篇
皮肤病学   101712篇
神经病学   351453篇
特种医学   164728篇
外国民族医学   1317篇
外科学   648307篇
综合类   96241篇
现状与发展   14篇
一般理论   1725篇
预防医学   331894篇
眼科学   103684篇
药学   319527篇
  16篇
中国医学   9365篇
肿瘤学   231066篇
  2018年   47389篇
  2017年   36318篇
  2016年   41384篇
  2015年   46488篇
  2014年   64557篇
  2013年   97768篇
  2012年   130526篇
  2011年   138726篇
  2010年   83075篇
  2009年   78458篇
  2008年   129481篇
  2007年   138618篇
  2006年   139838篇
  2005年   135053篇
  2004年   129997篇
  2003年   125444篇
  2002年   121368篇
  2001年   198389篇
  2000年   203305篇
  1999年   171812篇
  1998年   50447篇
  1997年   44447篇
  1996年   43848篇
  1995年   42330篇
  1994年   38874篇
  1993年   36613篇
  1992年   134563篇
  1991年   130565篇
  1990年   126914篇
  1989年   123221篇
  1988年   113253篇
  1987年   111327篇
  1986年   105322篇
  1985年   100863篇
  1984年   75841篇
  1983年   64703篇
  1982年   38566篇
  1981年   34589篇
  1979年   69471篇
  1978年   49238篇
  1977年   42399篇
  1976年   39161篇
  1975年   42626篇
  1974年   50787篇
  1973年   48944篇
  1972年   46082篇
  1971年   43089篇
  1970年   40160篇
  1969年   38496篇
  1968年   35896篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
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   
102.
103.
104.
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   
105.
106.
107.
108.
109.
110.
ABSTRACT

Objective

To investigate primary care physician clinical practice patterns, barriers, and education surrounding pediatric physical activity (PA), and to compare practice patterns by discipline.  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