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   2393048篇
  免费   168296篇
  国内免费   4476篇
耳鼻咽喉   35312篇
儿科学   75727篇
妇产科学   69944篇
基础医学   341534篇
口腔科学   70253篇
临床医学   203323篇
内科学   465638篇
皮肤病学   52169篇
神经病学   188440篇
特种医学   93959篇
外国民族医学   778篇
外科学   370796篇
综合类   53160篇
现状与发展   7篇
一般理论   714篇
预防医学   171432篇
眼科学   56442篇
药学   181519篇
  5篇
中国医学   4996篇
肿瘤学   129672篇
  2018年   21757篇
  2015年   21540篇
  2014年   29977篇
  2013年   45896篇
  2012年   61199篇
  2011年   65373篇
  2010年   38824篇
  2009年   37014篇
  2008年   63137篇
  2007年   68702篇
  2006年   69699篇
  2005年   68033篇
  2004年   65766篇
  2003年   63792篇
  2002年   62933篇
  2001年   109214篇
  2000年   112357篇
  1999年   95432篇
  1998年   26358篇
  1997年   23850篇
  1996年   23502篇
  1995年   22218篇
  1994年   21028篇
  1993年   19372篇
  1992年   75790篇
  1991年   74079篇
  1990年   72991篇
  1989年   71219篇
  1988年   66382篇
  1987年   65210篇
  1986年   62320篇
  1985年   59341篇
  1984年   44454篇
  1983年   38173篇
  1982年   22791篇
  1981年   20482篇
  1979年   42454篇
  1978年   30146篇
  1977年   26098篇
  1976年   24123篇
  1975年   26997篇
  1974年   31961篇
  1973年   30934篇
  1972年   29612篇
  1971年   27614篇
  1970年   25916篇
  1969年   25036篇
  1968年   23541篇
  1967年   20849篇
  1966年   19473篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
The aim of the present study was to evaluate the antimicrobial activity of two synbiotic combinations, Lactobacillus fermentum with short-chain fructooligosaccharides (FOS-LF) and Bifidobacterium longum with isomaltooligosaccharides (IMO-BL), against enterohaemorrhagic Escherichia coli O157:H7 and enteropathogenic E. coli O86. Antimicrobial activity was determined (1) by co-culturing the synbiotics and pathogens in batch cultures, and (2) with the three-stage continuous culture system (gut model), inoculated with faecal slurry from an elderly donor. In the co-culture experiments, IMO-BL was significantly inhibitory to both E. coli strains, while FOS-LF was slightly inhibitory or not inhibitory. Factors other than acid production appeared to play a role in the inhibition. In the gut models, both synbiotics effectively inhibited E. coli O157 in the first vessel, but not in vessels 2 and 3. E. coli O86 was not significantly inhibited.  相似文献   
42.
43.
44.
45.
46.
47.
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   
48.
49.
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   
50.
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