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   3158796篇
  免费   235872篇
  国内免费   4766篇
耳鼻咽喉   44953篇
儿科学   105114篇
妇产科学   85991篇
基础医学   459710篇
口腔科学   87569篇
临床医学   284330篇
内科学   611963篇
皮肤病学   69824篇
神经病学   249877篇
特种医学   120065篇
外国民族医学   1096篇
外科学   478170篇
综合类   67321篇
现状与发展   12篇
一般理论   1119篇
预防医学   247316篇
眼科学   74065篇
药学   235738篇
  11篇
中国医学   6179篇
肿瘤学   169011篇
  2019年   25163篇
  2018年   35061篇
  2017年   26343篇
  2016年   29502篇
  2015年   33261篇
  2014年   46842篇
  2013年   70674篇
  2012年   97321篇
  2011年   103692篇
  2010年   61784篇
  2009年   58374篇
  2008年   97471篇
  2007年   104146篇
  2006年   104981篇
  2005年   101678篇
  2004年   97926篇
  2003年   94434篇
  2002年   91913篇
  2001年   144824篇
  2000年   149043篇
  1999年   126123篇
  1998年   36537篇
  1997年   32188篇
  1996年   32571篇
  1995年   30906篇
  1994年   28722篇
  1993年   26847篇
  1992年   98558篇
  1991年   96572篇
  1990年   94009篇
  1989年   90234篇
  1988年   83053篇
  1987年   81836篇
  1986年   76474篇
  1985年   73609篇
  1984年   55022篇
  1983年   46720篇
  1982年   27734篇
  1981年   24983篇
  1979年   50373篇
  1978年   35738篇
  1977年   30015篇
  1976年   28489篇
  1975年   30780篇
  1974年   36492篇
  1973年   34934篇
  1972年   32577篇
  1971年   30489篇
  1970年   28426篇
  1969年   26756篇
排序方式: 共有10000条查询结果,搜索用时 234 毫秒
131.
132.
133.
134.
135.
136.
The present study aimed at measuring seropositivities for infection by Ascaris suum and Toxocara canis using the excretory/secretory (E/S) antigens from Ascaris suum (AES) and Toxocara canis (TES) within an indigenous population. In addition, quantification of cytokine expressions in peripheral blood cells was determined. A total of 50 Warao indigenous were included; of which 43 were adults and seven children. In adults, 44.1% were seropositive for both parasites; whereas children had only seropositivity to one or the other helminth. For ascariosis, the percentage of AES seropositivity in adults and children was high; 23.3% and 57.1%, respectively. While that for toxocariosis, the percentage of TES seropositivity in adults and children was low; 9.3% and 14.3%, respectively. The percentage of seronegativity was comparable for AES and TES antigens in adults (27.9%) and children (28.6%). When positive sera were analyzed by Western blotting technique using AES antigens; three bands of 97.2, 193.6 and 200.2 kDas were mostly recognized. When the TES antigens were used, nine major bands were mostly identified; 47.4, 52.2, 84.9, 98.2, 119.1, 131.3, 175.6, 184.4 and 193.6 kDas. Stool examinations showed that Blastocystis hominis, Hymenolepis nana and Entamoeba coli were the most commonly observed intestinal parasites. Quantification of cytokines IFN-γ, IL-2, IL-6, TGF-β, TNF-α, IL-10 and IL-4 expressions showed that there was only a significant increased expression of IL-4 in indigenous with TES seropositivity (p < 0.002). Ascaris and Toxocara seropositivity was prevalent among Warao indigenous.  相似文献   
137.
138.
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   
139.
A 42‐year‐old man presented with a viral prodrome and tested positive for influenza A. He rapidly deteriorated developing cardiogenic shock, rhabdomyolysis, and acute kidney injury. Patient improved 1 week later with supportive measures including vasopressors, inotropes, and an intraaortic balloon pump. We report this case as it highlights the discordance between echocardiographic ventricular wall thickening as a result of myocardial edema, and electrocardiographic findings at presentation, with a reversal in findings at time of resolution. Additionally, there was some suggestion of a regional pattern to the reduced longitudinal strain.  相似文献   
140.
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