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   2676435篇
  免费   212718篇
  国内免费   7942篇
耳鼻咽喉   36101篇
儿科学   87786篇
妇产科学   74340篇
基础医学   373659篇
口腔科学   78213篇
临床医学   237591篇
内科学   536124篇
皮肤病学   61606篇
神经病学   219053篇
特种医学   106383篇
外国民族医学   721篇
外科学   407445篇
综合类   64011篇
现状与发展   5篇
一般理论   940篇
预防医学   215021篇
眼科学   59596篇
药学   194578篇
  8篇
中国医学   5002篇
肿瘤学   138912篇
  2018年   28929篇
  2016年   24896篇
  2015年   28397篇
  2014年   38889篇
  2013年   58880篇
  2012年   77533篇
  2011年   82460篇
  2010年   49433篇
  2009年   46670篇
  2008年   76978篇
  2007年   81628篇
  2006年   82637篇
  2005年   80296篇
  2004年   77365篇
  2003年   74432篇
  2002年   71708篇
  2001年   122346篇
  2000年   126393篇
  1999年   106247篇
  1998年   30768篇
  1997年   27694篇
  1996年   28347篇
  1995年   28029篇
  1994年   26298篇
  1993年   24719篇
  1992年   87710篇
  1991年   85411篇
  1990年   82652篇
  1989年   79458篇
  1988年   73890篇
  1987年   72781篇
  1986年   68941篇
  1985年   66610篇
  1984年   50460篇
  1983年   43002篇
  1982年   26160篇
  1981年   23521篇
  1980年   22146篇
  1979年   47147篇
  1978年   33454篇
  1977年   28320篇
  1976年   26356篇
  1975年   27843篇
  1974年   33517篇
  1973年   32262篇
  1972年   29687篇
  1971年   27787篇
  1970年   25544篇
  1969年   23994篇
  1968年   22078篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
43.
44.
45.
46.
47.
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   
48.
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   
49.
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   
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