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   1696809篇
  免费   123454篇
  国内免费   3781篇
耳鼻咽喉   21735篇
儿科学   55651篇
妇产科学   46163篇
基础医学   241413篇
口腔科学   48755篇
临床医学   151472篇
内科学   333690篇
皮肤病学   38663篇
神经病学   131328篇
特种医学   63906篇
外国民族医学   242篇
外科学   257379篇
综合类   38962篇
现状与发展   4篇
一般理论   536篇
预防医学   124347篇
眼科学   40217篇
药学   123739篇
  7篇
中国医学   4476篇
肿瘤学   101359篇
  2021年   12794篇
  2019年   13534篇
  2018年   19963篇
  2017年   15223篇
  2016年   16631篇
  2015年   18988篇
  2014年   26235篇
  2013年   37967篇
  2012年   52777篇
  2011年   55463篇
  2010年   32801篇
  2009年   30727篇
  2008年   51572篇
  2007年   54860篇
  2006年   55323篇
  2005年   52600篇
  2004年   50791篇
  2003年   48216篇
  2002年   46411篇
  2001年   91808篇
  2000年   93626篇
  1999年   76980篇
  1998年   19731篇
  1997年   17277篇
  1996年   17405篇
  1995年   16749篇
  1994年   15300篇
  1993年   14075篇
  1992年   57401篇
  1991年   55293篇
  1990年   52986篇
  1989年   50761篇
  1988年   46146篇
  1987年   44948篇
  1986年   42237篇
  1985年   40003篇
  1984年   29363篇
  1983年   24925篇
  1982年   13905篇
  1979年   25548篇
  1978年   17582篇
  1977年   14917篇
  1976年   13884篇
  1975年   14574篇
  1974年   17636篇
  1973年   16951篇
  1972年   15682篇
  1971年   14459篇
  1970年   13436篇
  1969年   12525篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
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   
62.
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   
63.
64.
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   
65.
66.
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   
67.
68.
69.
70.
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