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   1640239篇
  免费   137259篇
  国内免费   3912篇
耳鼻咽喉   22143篇
儿科学   53823篇
妇产科学   46866篇
基础医学   231785篇
口腔科学   48059篇
临床医学   145475篇
内科学   320745篇
皮肤病学   34668篇
神经病学   132505篇
特种医学   66331篇
外国民族医学   474篇
外科学   248254篇
综合类   45582篇
现状与发展   11篇
一般理论   563篇
预防医学   127183篇
眼科学   36911篇
药学   125392篇
  36篇
中国医学   4981篇
肿瘤学   89623篇
  2018年   15947篇
  2016年   14070篇
  2015年   16325篇
  2014年   22150篇
  2013年   33887篇
  2012年   46139篇
  2011年   48522篇
  2010年   28977篇
  2009年   27325篇
  2008年   46162篇
  2007年   48374篇
  2006年   48927篇
  2005年   47033篇
  2004年   46018篇
  2003年   43944篇
  2002年   42843篇
  2001年   76755篇
  2000年   79448篇
  1999年   66889篇
  1998年   17894篇
  1997年   16474篇
  1996年   16417篇
  1995年   16127篇
  1994年   15173篇
  1993年   14314篇
  1992年   55510篇
  1991年   53875篇
  1990年   52629篇
  1989年   50920篇
  1988年   47312篇
  1987年   46649篇
  1986年   44358篇
  1985年   42975篇
  1984年   32163篇
  1983年   27659篇
  1982年   16231篇
  1981年   14503篇
  1980年   13628篇
  1979年   30526篇
  1978年   21112篇
  1977年   17811篇
  1976年   16723篇
  1975年   17598篇
  1974年   21501篇
  1973年   20685篇
  1972年   18859篇
  1971年   17777篇
  1970年   16289篇
  1969年   15254篇
  1968年   13942篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
53.
54.
55.
56.
57.
58.
The identification of EGFR mutations in non‐small‐cell lung cancer is important for selecting patients, who may benefit from treatment with EGFR tyrosine kinase inhibitors. The analysis is usually performed on cytological aspirates and/or histological needle biopsies, representing a small fraction of the tumour volume. The aim of the present investigation was to evaluate the diagnostic performance of this molecular test. We retrospectively included 201 patients with primary adenocarcinoma of the lung. EGFR mutation status (exon 19 deletions and exon 21 L858R point mutation) was evaluated on both pre‐operative biopsies (131 histological and 70 cytological) and on the surgical specimens, using PCR. Samples with low tumour cell fraction were assigned to laser micro‐dissection (LMD). We found nine (4.5%) patients with EGFR mutation in the lung tumour resections, but failed to identify mutation in one of the corresponding pre‐operative, cytological specimens. Several (18.4%) analyses of the pre‐operative biopsies were inconclusive, especially in case of biopsies undergoing LMD and regarding exon 21 analysis. Discrepancy of mutation status in one patient may reflect intra‐tumoural heterogeneity or technical issues. Moreover, several inconclusive results in the diagnostic biopsies reveal that attention must be paid on the suitability of pre‐operative biopsies for EGFR mutation analysis.  相似文献   
59.
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   
60.
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