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   1720379篇
  免费   125715篇
  国内免费   3882篇
耳鼻咽喉   21940篇
儿科学   56563篇
妇产科学   46820篇
基础医学   244718篇
口腔科学   49118篇
临床医学   154958篇
内科学   338666篇
皮肤病学   39223篇
神经病学   133735篇
特种医学   64408篇
外国民族医学   246篇
外科学   259670篇
综合类   39156篇
现状与发展   4篇
一般理论   542篇
预防医学   126740篇
眼科学   40544篇
药学   125273篇
  7篇
中国医学   4503篇
肿瘤学   103142篇
  2021年   13537篇
  2019年   14432篇
  2018年   20919篇
  2017年   15971篇
  2016年   17433篇
  2015年   19832篇
  2014年   27277篇
  2013年   39414篇
  2012年   54633篇
  2011年   57212篇
  2010年   33897篇
  2009年   31721篇
  2008年   53101篇
  2007年   56361篇
  2006年   56696篇
  2005年   53930篇
  2004年   52042篇
  2003年   49292篇
  2002年   47477篇
  2001年   91985篇
  2000年   93790篇
  1999年   77173篇
  1998年   19974篇
  1997年   17463篇
  1996年   17551篇
  1995年   16898篇
  1994年   15413篇
  1993年   14178篇
  1992年   57460篇
  1991年   55361篇
  1990年   53050篇
  1989年   50813篇
  1988年   46189篇
  1987年   44985篇
  1986年   42290篇
  1985年   40038篇
  1984年   29411篇
  1983年   24967篇
  1982年   13971篇
  1979年   25560篇
  1978年   17611篇
  1977年   14947篇
  1976年   13924篇
  1975年   14603篇
  1974年   17669篇
  1973年   16969篇
  1972年   15698篇
  1971年   14473篇
  1970年   13448篇
  1969年   12535篇
排序方式: 共有10000条查询结果,搜索用时 2 毫秒
51.
The aim of this study is to review the literature to find out the exact etiology of anastomotic cancers of colon post resection and differentiate them between a recurrence, second primary, and metastatic disease (local manifestation of systemic disease). Web-based literature search was done, and datas collected. We searched PubMed for papers using the keywords colon cancer recurrence, anastomotic recurrence, and recurrent colon carcinoma. We also searched for systematic review in the same topic. In addition, we used our personal referrence archive. Anastomotic recurrences of colon are postulated to arise due to inadequate margins, tumor implantation by exfoliated cells, altered biological properties of bowel anastomosis, and missed synchronous lesions. Some tumors are unique with repeated recurrence after repeated resection. Duration after primary surgery plays a major role in differentiating recurrent and second primary lesions. Repeated recurrences after repeated resections have to be considered a manifestation of systemic disease or metastatic disease due to the virulence of the disease. A detailed analysis and study of patients with colonic anastomotic lesion are required to differentiate it between a recurrent, a second primary lesion, and a metastatic disease (local manifestation of a systemic disease). The nomenclature is significant to study the survival of these patients, as a second primary lesion will have different survival compared to that of recurrent lesions.  相似文献   
52.
53.
ObjectivesTo fill an empirical gap in the literature by examining changes in quality of care measures occurring when multispecialty clinic systems were acquired by hospital-owned, vertically integrated health care delivery systems in the Twin Cities area.ConclusionsMoving a clinic system into a vertically integrated delivery system resulted in limited increases in quality of care indicators. Caution is warranted when the acquisition causes disruption in referral patterns.  相似文献   
54.
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   
55.
56.
57.
58.
59.
60.
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