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   3435445篇
  免费   280994篇
  国内免费   13307篇
耳鼻咽喉   46809篇
儿科学   109022篇
妇产科学   89246篇
基础医学   547190篇
口腔科学   92848篇
临床医学   313019篇
内科学   606088篇
皮肤病学   91138篇
神经病学   293514篇
特种医学   133879篇
外国民族医学   288篇
外科学   523979篇
综合类   102245篇
现状与发展   24篇
一般理论   2360篇
预防医学   294258篇
眼科学   77981篇
药学   234741篇
  26篇
中国医学   9325篇
肿瘤学   161766篇
  2021年   54840篇
  2020年   34965篇
  2019年   57876篇
  2018年   71120篇
  2017年   54228篇
  2016年   59634篇
  2015年   73799篇
  2014年   107870篇
  2013年   172963篇
  2012年   93564篇
  2011年   94039篇
  2010年   116719篇
  2009年   121073篇
  2008年   81277篇
  2007年   84699篇
  2006年   94631篇
  2005年   90349篇
  2004年   91959篇
  2003年   82694篇
  2002年   72537篇
  2001年   102480篇
  2000年   95151篇
  1999年   95213篇
  1998年   64518篇
  1997年   62581篇
  1996年   60735篇
  1995年   56170篇
  1994年   50431篇
  1993年   47109篇
  1992年   67548篇
  1991年   64804篇
  1990年   61430篇
  1989年   60597篇
  1988年   56434篇
  1987年   55209篇
  1986年   52634篇
  1985年   52221篇
  1984年   48144篇
  1983年   44315篇
  1982年   41703篇
  1981年   39421篇
  1980年   37153篇
  1979年   40658篇
  1978年   36251篇
  1977年   32839篇
  1976年   30125篇
  1975年   29006篇
  1974年   30490篇
  1973年   29601篇
  1972年   27859篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
261.
262.
263.
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   
264.
265.
266.
Demodex mites are microscopic arachnids found in the normal skin of many mammals. In humans, it is well established that Demodex mite density is higher in patients with the skin condition rosacea, and treatment with acaricidal agents is effective in resolving symptoms. However, pathophysiology of rosacea is complex and multifactorial. In dogs, demodicosis is a significant veterinary issue, particularly the generalized form of the disease which can be fatal if untreated. In each species, clinical and molecular studies have shown that the host’s immunological interactions with Demodex mites are an important, but not fully understood, aspect of how Demodex can live in the skin either as a harmless commensal organism or as a pathogenic agent. This review outlines the role of Demodex mites in humans and dogs, considering morphology, prevalence, symptoms, diagnosis, histology treatment and pathogenesis.  相似文献   
267.
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   
268.
269.
270.
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