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   4354588篇
  免费   362771篇
  国内免费   15952篇
耳鼻咽喉   62629篇
儿科学   134976篇
妇产科学   112838篇
基础医学   659067篇
口腔科学   119804篇
临床医学   400806篇
内科学   793978篇
皮肤病学   107458篇
神经病学   374491篇
特种医学   173436篇
外国民族医学   912篇
外科学   670466篇
综合类   126536篇
现状与发展   91篇
一般理论   2615篇
预防医学   365858篇
眼科学   102535篇
药学   303709篇
  24篇
中国医学   11398篇
肿瘤学   209684篇
  2021年   56975篇
  2020年   37978篇
  2019年   59491篇
  2018年   76644篇
  2017年   59206篇
  2016年   65855篇
  2015年   79062篇
  2014年   116524篇
  2013年   181833篇
  2012年   121649篇
  2011年   124895篇
  2010年   127823篇
  2009年   132096篇
  2008年   111803篇
  2007年   117767篇
  2006年   128012篇
  2005年   122281篇
  2004年   122580篇
  2003年   112926篇
  2002年   103329篇
  2001年   155584篇
  2000年   151336篇
  1999年   140520篇
  1998年   72738篇
  1997年   68965篇
  1996年   66522篇
  1995年   62320篇
  1994年   56089篇
  1993年   51970篇
  1992年   103875篇
  1991年   99368篇
  1990年   94360篇
  1989年   92024篇
  1988年   85574篇
  1987年   84016篇
  1986年   79717篇
  1985年   78088篇
  1984年   66048篇
  1983年   58938篇
  1982年   48215篇
  1981年   44934篇
  1980年   42221篇
  1979年   57855篇
  1978年   47064篇
  1977年   41643篇
  1976年   38686篇
  1975年   37873篇
  1974年   42452篇
  1973年   40576篇
  1972年   38044篇
排序方式: 共有10000条查询结果,搜索用时 9 毫秒
61.
62.
63.
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   
64.
65.
66.
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   
67.
68.
69.
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   
70.
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