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   1692984篇
  免费   126355篇
  国内免费   3778篇
耳鼻咽喉   21743篇
儿科学   55640篇
妇产科学   46164篇
基础医学   241303篇
口腔科学   48747篇
临床医学   151348篇
内科学   333585篇
皮肤病学   38652篇
神经病学   131158篇
特种医学   63888篇
外国民族医学   242篇
外科学   257261篇
综合类   38945篇
现状与发展   4篇
一般理论   531篇
预防医学   124250篇
眼科学   40221篇
药学   123633篇
  7篇
中国医学   4475篇
肿瘤学   101320篇
  2021年   12787篇
  2019年   13534篇
  2018年   19959篇
  2017年   15220篇
  2016年   16621篇
  2015年   18962篇
  2014年   26225篇
  2013年   37955篇
  2012年   52732篇
  2011年   55434篇
  2010年   32779篇
  2009年   30699篇
  2008年   51532篇
  2007年   54806篇
  2006年   55268篇
  2005年   52557篇
  2004年   50749篇
  2003年   48173篇
  2002年   46387篇
  2001年   91802篇
  2000年   93620篇
  1999年   76974篇
  1998年   19726篇
  1997年   17280篇
  1996年   17393篇
  1995年   16747篇
  1994年   15294篇
  1993年   14077篇
  1992年   57390篇
  1991年   55283篇
  1990年   52975篇
  1989年   50756篇
  1988年   46139篇
  1987年   44943篇
  1986年   42232篇
  1985年   39992篇
  1984年   29357篇
  1983年   24911篇
  1982年   13903篇
  1979年   25537篇
  1978年   17578篇
  1977年   14911篇
  1976年   13876篇
  1975年   14568篇
  1974年   17637篇
  1973年   16948篇
  1972年   15678篇
  1971年   14455篇
  1970年   13432篇
  1969年   12517篇
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
91.
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   
92.
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   
93.
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   
94.
95.
96.
97.
98.
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   
99.
100.
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