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   3211729篇
  免费   229029篇
  国内免费   8655篇
耳鼻咽喉   43212篇
儿科学   107293篇
妇产科学   88669篇
基础医学   453839篇
口腔科学   89250篇
临床医学   293280篇
内科学   627886篇
皮肤病学   75642篇
神经病学   262394篇
特种医学   123401篇
外国民族医学   1011篇
外科学   478085篇
综合类   67486篇
现状与发展   5篇
一般理论   1263篇
预防医学   248619篇
眼科学   72236篇
药学   234099篇
  11篇
中国医学   6560篇
肿瘤学   175172篇
  2019年   25022篇
  2018年   35444篇
  2017年   27256篇
  2016年   31355篇
  2015年   35345篇
  2014年   48627篇
  2013年   73768篇
  2012年   97753篇
  2011年   103485篇
  2010年   62264篇
  2009年   59407篇
  2008年   96779篇
  2007年   102675篇
  2006年   104607篇
  2005年   100229篇
  2004年   96950篇
  2003年   93618篇
  2002年   90253篇
  2001年   152934篇
  2000年   156709篇
  1999年   132209篇
  1998年   38025篇
  1997年   33902篇
  1996年   33973篇
  1995年   32912篇
  1994年   30330篇
  1993年   28282篇
  1992年   103605篇
  1991年   100086篇
  1990年   97301篇
  1989年   93971篇
  1988年   85914篇
  1987年   84706篇
  1986年   79316篇
  1985年   75956篇
  1984年   56645篇
  1983年   48015篇
  1982年   28568篇
  1981年   25587篇
  1979年   50483篇
  1978年   35879篇
  1977年   30431篇
  1976年   28363篇
  1975年   30088篇
  1974年   35839篇
  1973年   34149篇
  1972年   31786篇
  1971年   29593篇
  1970年   27269篇
  1969年   26019篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
52.
Red cell exchange (RCE) is a common procedure in adults with sickle cell disease (SCD). Implantable dual lumen Vortex (DLV) ports can be used for RCE in patients with poor peripheral venous access. We performed a retrospective cohort study of RCE procedures performed in adults with SCD. The main objective of the study was to compare the inlet speed, duration of procedures and rate of complications performed through DLV ports to those performed through temporary central venous and peripheral catheters. Twenty‐nine adults with SCD underwent a total of 318 RCE procedures. Twenty adults had DLV ports placed and 218 procedures were performed using DLV ports. Mean length of follow‐up after DLV port placement was 397 ± 263 days. Six DLV ports were removed due to infection and 1 for malfunction after a mean of 171 ± 120 days. Compared to temporary central venous and peripheral catheters, DLV port procedures had a greater rate of procedural complications, a longer duration, and a lower inlet speed (all P < 0.01). When accounting for the maximum allowable inlet speed to avoid citrate toxicity, 40% of DLV port procedures were greater than 10% below maximum speed, compared to 7 and 14% of procedures performed through temporary central venous and peripheral catheters (P < 0.0001). In conclusion, DLV ports can be used for RCE in adults with SCD, albeit with more procedural complications and longer duration. The smaller internal diameter and longer catheter of DLV ports compared to temporary central venous catheters likely accounts for the differences noted. J. Clin. Apheresis 30:353–358, 2015. © 2015 Wiley Periodicals, Inc.  相似文献   
53.
54.
55.
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   
56.
57.
58.
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   
59.
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   
60.
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