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   3613574篇
  免费   266670篇
  国内免费   8737篇
耳鼻咽喉   49405篇
儿科学   119628篇
妇产科学   100631篇
基础医学   508541篇
口腔科学   103662篇
临床医学   328576篇
内科学   702430篇
皮肤病学   83529篇
神经病学   297355篇
特种医学   140880篇
外国民族医学   1129篇
外科学   540397篇
综合类   79419篇
现状与发展   6篇
一般理论   1419篇
预防医学   281058篇
眼科学   82562篇
药学   267555篇
  10篇
中国医学   7027篇
肿瘤学   193762篇
  2018年   38430篇
  2017年   29836篇
  2016年   34378篇
  2015年   38774篇
  2014年   53218篇
  2013年   80964篇
  2012年   107594篇
  2011年   113924篇
  2010年   68316篇
  2009年   65102篇
  2008年   107262篇
  2007年   113704篇
  2006年   115370篇
  2005年   111105篇
  2004年   107938篇
  2003年   104052篇
  2002年   100818篇
  2001年   168198篇
  2000年   173095篇
  1999年   146194篇
  1998年   42273篇
  1997年   37766篇
  1996年   37747篇
  1995年   36623篇
  1994年   33923篇
  1993年   31879篇
  1992年   116147篇
  1991年   112693篇
  1990年   109437篇
  1989年   106040篇
  1988年   97760篇
  1987年   96056篇
  1986年   90840篇
  1985年   87126篇
  1984年   65298篇
  1983年   55807篇
  1982年   33093篇
  1981年   29748篇
  1979年   59799篇
  1978年   41947篇
  1977年   35663篇
  1976年   33266篇
  1975年   35443篇
  1974年   42427篇
  1973年   40473篇
  1972年   37772篇
  1971年   35296篇
  1970年   32526篇
  1969年   31113篇
  1968年   28460篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
101.
102.
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   
103.
104.
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   
105.
106.
107.
There is an increasing number of effective therapies for fracture prevention in adults at risk of osteoporosis. However, shortcomings in the evidence underpinning our management of osteoporosis still exist. Evidence of antifracture efficacy in the groups of patients who most commonly use calcium and vitamin D supplements is lacking, the safety of calcium supplements is in doubt, and the safety and efficacy of high doses of vitamin D give cause for concern. Alendronate, risedronate, zoledronate and denosumab have been shown to prevent spine, nonspine and hip fractures; in addition, teriparatide and strontium ranelate prevent both spine and nonspine fractures, and raloxifene and ibandronate prevent spine fractures. However, most trials provide little information regarding long‐term efficacy or safety. A particular concern at present is the possibility that oral bisphosphonates might cause atypical femoral fractures. Observational data suggest that the incidence of this type of fracture increases steeply with duration of bisphosphonate use, resulting in concern that the benefit–risk balance may become negative in the long term, particularly in patients in whom the osteoporotic fracture risk is not high. Therefore, reappraisal of ongoing use of bisphosphonates after about 5 years is endorsed by expert consensus, and ‘drug holidays’ should be considered at this time. Further studies are needed to guide clinical practice in this area.  相似文献   
108.
The value of adding simeprevir (SMV) vs placebo (PBO) to peginterferon and ribavirin (PR) for treatment of chronic hepatitis C virus infection was examined using patient‐reported outcomes (PROs); further, concordance of PROs with virology endpoints and adverse events (AEs) was explored. Patients (= 768 SMV/PR,= 393 PBO/PR) rated fatigue (FSS), depressive symptoms (CES‐D) and functional impairment (WPAI: Hepatitis C Productivity, Daily Activity and Absenteeism) at baseline and throughout treatment in three randomised, double‐blind trials comparing the addition of SMV or PBO during initial 12 weeks of PR. PR was administered for 48 weeks (PBO group) and 24/48 weeks (SMV group) using a response‐guided therapy (RGT) approach. Mean PRO scores (except Absenteeism) worsened from baseline to Week 4 to the same extent in both groups but reverted after Week 24 for SMV/PR and only after Week 48 for PBO/PR. Accordingly, there was a significantly lower area under the curve (baseline–Week 60, AUC60) and fewer weeks with clinically important worsening of scores in the SMV/PR group at any time point. Incidences of patients with fatigue and anaemia AEs were similar in both groups, but FSS scores showed that clinically important increases in fatigue lasted a mean of 6.9 weeks longer with PBO/PR (P < 0.001). PRO score subgroup analysis indicated better outcomes for patients who met the criteria for RGT or achieved sustained virological response 12 weeks post‐treatment (SVR12); differences in mean PRO scores associated with fibrosis level were only observed with PBO/PR. Greater efficacy of SMV/PR enabled reduced treatment duration and reduced time with PR‐related AEs without adding to AE severity.  相似文献   
109.
Platelet transfusions are a life-saving medical intervention used for the treatment of thrombocytopenia or hemorrhage. Extensive research has gone into trying to understand how to store platelets prior to the transfusion event. Much has been learned about storage bag materials, synthetic solutions, and how temperature impacts platelet viability and function. While room temperature storage of platelets preserves 24-hour in vivo platelet recovery and survival there is a greater risk for bacterial growth. Therefore, cold storage of platelets has become attractive due to the reduction in potential bacterial proliferation and the maintenance of platelet function beyond 5 days of storage. Cold stored platelets, however, have their own set of challenges. Cold stored platelets become activated through several mechanisms. The morphological and molecular changes that occur due to cold exposure enhance their ability to participate in the hemostatic process at the cost of rapid clearance from circulation. This review focuses on the underlying mechanisms leading to cold platelet activation and the receptor modifications involved in platelet clearance.  相似文献   
110.
European Journal of Orthopaedic Surgery & Traumatology - The goals of this study were to compare patient satisfaction and wound-related complications in patients receiving 2-octyl cyanoacrylate...  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