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   192549篇
  免费   1883篇
  国内免费   50篇
耳鼻咽喉   1296篇
儿科学   7086篇
妇产科学   3782篇
基础医学   18756篇
口腔科学   2013篇
临床医学   13816篇
内科学   34145篇
皮肤病学   1061篇
神经病学   18291篇
特种医学   9807篇
外国民族医学   3篇
外科学   31257篇
综合类   2437篇
一般理论   38篇
预防医学   19185篇
眼科学   2945篇
药学   10549篇
中国医学   648篇
肿瘤学   17367篇
  2022年   135篇
  2021年   223篇
  2020年   160篇
  2019年   238篇
  2018年   22190篇
  2017年   17553篇
  2016年   19736篇
  2015年   1174篇
  2014年   1223篇
  2013年   1310篇
  2012年   7776篇
  2011年   21826篇
  2010年   19211篇
  2009年   11939篇
  2008年   20100篇
  2007年   22378篇
  2006年   1381篇
  2005年   2883篇
  2004年   4020篇
  2003年   5031篇
  2002年   3134篇
  2001年   923篇
  2000年   1095篇
  1999年   654篇
  1998年   450篇
  1997年   417篇
  1996年   215篇
  1995年   234篇
  1994年   198篇
  1993年   202篇
  1992年   389篇
  1991年   395篇
  1990年   464篇
  1989年   403篇
  1988年   348篇
  1987年   342篇
  1986年   304篇
  1985年   285篇
  1984年   198篇
  1983年   186篇
  1982年   135篇
  1980年   128篇
  1979年   207篇
  1978年   131篇
  1975年   167篇
  1974年   193篇
  1973年   148篇
  1972年   149篇
  1970年   157篇
  1969年   128篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
The treatment of deep cartilage defects in load-bearing joints is a problem that still has no satisfactory solution. Full-thickness defects of the articular cartilage rarely heal spontaneously, usually leaving damage that can lead to early arthrosis. Techniques currently available for the treatment of chondral defects include abrasion, drilling, micro-fracturing, transplantation of tissue autografts and allografts, and cell transplantation. Osteochondral autograft transplantation is currently the only surgical cartilage repair technique known to lead to the formation of genuine hyaline articular cartilage and its retention at least in the medium term. The Draenert method, in which a water-cooled diamond bone-cutting system is used, is an effective procedure for resurfacing the joints affected by localised cartilaginous defects, even when there is also severe bone loss. Donor-side morbidity can be kept to a minimum by filling the defect caused by harvesting with a press-fit cylinder of cancellous bone covered with periosteum for protection.  相似文献   
42.
Ischemic injury plays an important role in chronic renal transplant failure (CRTF). Down-regulation of ecto-adenosine triphosphatase (ATPase) in combination with up-regulation of ecto-5'-nucleotidase is a hallmark of ischemic injury. We studied the expression of renal ecto-5'-nucleotidase and ecto-ATPase in experimental renal transplantation. Fisher 344-to-Lewis allografted rats were either treated with an angiotensin-converting enzyme inhibitor (ACEi) or left untreated. Lewis-to-Lewis syngrafted rats served as controls. Untreated allografted rats developed proteinuria, glomerulosclerosis, and mild intimal hyperplasia. ACEi completely prevented focal and segmental glomerulosclerosis (FGS) and proteinuria, but significantly enhanced intimal hyperplasia. Untreated allografted rats revealed marked vascular ecto-5'-nucleotidase activity, which increased with ACEi. Vascular ecto-5'-nucleotidase activity was absent in syngrafted animals. Ecto-5'-nucleotidase activity correlated well with intimal hyperplasia. Glomerular ecto-ATPase expression was significantly reduced in untreated allografted rats compared to syngrafted rats and correlated well with the extent of FGS. ACEi prevented reduction in glomerular ecto-ATPase. We found de-novo expression of ecto-5'-nucleotidase at sites of renal intimal hyperplasia. Glomerular ecto-ATPase expression was markedly reduced in allografted rats and was prevented by ACEi. These enzyme expression patterns suggest local ischemic damage in experimental CRTF.  相似文献   
43.
Contemporary discourse contains numerous examples of use of the concept of culture by social and behavioral scientists. Simple reification, where the speaker makes culture into a thing capable of action exemplifies one usage in public discourse. Some quantitative social scientists attempt to characterize people’s cultural identities by means of a single categorical variable, which often “lumps” people into categories such as “Hispanic” or “Black” that in fact have numerous culturally bounded subcategories. Approaches that emphasize cultural process are preferable to those who attempt to categorize; more complex measures of acculturation help investigators to make convincing analyses of circumstances in which health disparities occur. Examples in which investigators make appropriate use of cultural characterizations demonstrate their utility in investigating health disparities in Haitian American women, injecting and noninjecting drug users, Hispanic youth, and adult Hispanics at risk of HIV infection. Focus on culture in the study of health disparities can identify entanglements between structural factors such as poverty and lack of education and cultural factors such as beliefs about health. Qualitative methods coupled with quantitative methods have great potential to improve investigators’ grasp of cultural nuance while capturing the distribution of qualitatively derived behaviors.  相似文献   
44.
45.
46.
The specific characteristics of genetic data lead to ethical-legal conflicts in the framework of genetic diagnosis. Several international organisations, including UNESCO and the Council of Europe, have enacted rules referring to the use of genetic information. This paper discusses possible legal and ethical criteria that could be used in genetic testing.  相似文献   
47.
48.
49.

Introduction  

This paper presents the results of a study on the psychometric properties of an authorized Spanish version of the McMaster Family Assessment Device, a self-report measure of family functioning.  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