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   1709583篇
  免费   121218篇
  国内免费   3411篇
耳鼻咽喉   24298篇
儿科学   49912篇
妇产科学   46488篇
基础医学   242334篇
口腔科学   50000篇
临床医学   145560篇
内科学   339773篇
皮肤病学   35974篇
神经病学   134119篇
特种医学   68153篇
外国民族医学   411篇
外科学   274414篇
综合类   34705篇
现状与发展   1篇
一般理论   469篇
预防医学   119022篇
眼科学   39193篇
药学   127390篇
  3篇
中国医学   3668篇
肿瘤学   98325篇
  2018年   16636篇
  2017年   13108篇
  2016年   14255篇
  2015年   16215篇
  2014年   22601篇
  2013年   34208篇
  2012年   46197篇
  2011年   48698篇
  2010年   29249篇
  2009年   28025篇
  2008年   47383篇
  2007年   49790篇
  2006年   50735篇
  2005年   49352篇
  2004年   47500篇
  2003年   45824篇
  2002年   45052篇
  2001年   88312篇
  2000年   91179篇
  1999年   76773篇
  1998年   19384篇
  1997年   17432篇
  1996年   17385篇
  1995年   16201篇
  1994年   15309篇
  1993年   14190篇
  1992年   59103篇
  1991年   56639篇
  1990年   55025篇
  1989年   53382篇
  1988年   48969篇
  1987年   48095篇
  1986年   45344篇
  1985年   43287篇
  1984年   31528篇
  1983年   26779篇
  1982年   14926篇
  1981年   13053篇
  1979年   28591篇
  1978年   19617篇
  1977年   16712篇
  1976年   15114篇
  1975年   16661篇
  1974年   20108篇
  1973年   19033篇
  1972年   18107篇
  1971年   16904篇
  1970年   16262篇
  1969年   15240篇
  1968年   14177篇
排序方式: 共有10000条查询结果,搜索用时 234 毫秒
51.
Behçet disease is a complex, multisystem disease characterized by recurrent oral and genital ulcerations. It rarely occurs in infants or children. Neonatal Behçet disease has been reported in infants whose ulcers resolve at or before 9 weeks of age. Few cases of neonatal Behçet disease persisting into childhood have previously been reported. We report the case of a 1‐month‐old infant who presented with severe recurrent genital ulcerations and at 6 months developed recurrent oral ulcerations. Her orogenital ulcerations continue to recur. Human leukocyte antigen testing revealed HLA‐B51 and B44 positivity. This is a case of pediatric Behçet disease in the neonatal period. Behçet disease should be considered in the differential diagnosis of recurrent genital and oral ulcerations in infants and children.  相似文献   
52.
53.
54.
55.
56.
57.
58.
59.
Preimplantation genetic diagnosis (PGD) was originally developed to diagnose embryo-related genetic abnormalities for couples who present a high risk of a specific inherited disorder. Because this technology involves embryo selection, the medical, bioethical, and legal implications of the technique have been debated, particularly when it is used to select features that are not related to serious diseases. Although several initiatives have attempted to achieve regulatory harmonization, the diversity of healthcare services available and the presence of cultural differences have hampered attempts to achieve this goal. Thus, in different countries, the provision of PGD and regulatory frameworks reflect the perceptions of scientific groups, legislators, and society regarding this technology. In Brazil, several texts have been analyzed by the National Congress to regulate the use of assisted reproduction technologies. Legislative debates, however, are not conclusive, and limited information has been published on how PGD is specifically regulated. The country requires the development of new regulatory standards to ensure adequate access to this technology and to guarantee its safe practice. This study examined official documents published on PGD regulation in Brazil and demonstrated how little direct oversight of PGD currently exists. It provides relevant information to encourage reflection on a particular regulation model in a Brazilian context, and should serve as part of the basis to enable further reform of the clinical practice of PGD in the country.  相似文献   
60.
Past research suggests that as many as 50% of onward human immunodeficiency virus (HIV) transmissions occur during acute and recent HIV infection. It is clearly important to develop interventions which focus on this highly infectious stage of HIV infection to prevent further transmission in the risk networks of acutely and recently infected individuals. Project Protect tries to find recently and acutely infected individuals and prevents HIV transmission in their risk networks. Participants are recruited by community health outreach workers at community-based HIV testing sites and drug users' community venues, by coupon referrals and through referrals from AIDS clinics. When a network with acute/recent infection is identified, network members are interviewed about their risky behaviors, network information is collected, and blood is drawn for HIV testing. Participants are also educated and given prevention materials (condoms, syringes, educational materials); HIV-infected participants are referred to AIDS clinics and are assisted with access to care. Community alerts about elevated risk of HIV transmission are distributed within the risk networks of recently infected. Overall, 342 people were recruited to the project and screened for acute/recent HIV infection. Only six index cases of recent infection (2.3% of all people screened) were found through primary screening at voluntary counseling and testing (VCT) sites, but six cases of recent infection were found through contact tracing of these recently infected participants (7% of network members who came to the interview). Combining screening at VCT sites and contact tracing the number of recently infected people we located as compared to VCT screening alone. No adverse events were encountered. These first results provide evidence for the theory behind the intervention, i.e., in the risk networks of recently infected people there are other people with recent HIV infection and they can be successfully located without increasing stigma for project participants.  相似文献   
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