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   2196277篇
  免费   159520篇
  国内免费   5088篇
耳鼻咽喉   31451篇
儿科学   70255篇
妇产科学   63277篇
基础医学   312000篇
口腔科学   65061篇
临床医学   192582篇
内科学   424637篇
皮肤病学   50220篇
神经病学   175587篇
特种医学   86456篇
外国民族医学   720篇
外科学   335383篇
综合类   50915篇
现状与发展   6篇
一般理论   817篇
预防医学   162543篇
眼科学   51714篇
药学   162705篇
  6篇
中国医学   4677篇
肿瘤学   119873篇
  2018年   21630篇
  2016年   19516篇
  2015年   21607篇
  2014年   29859篇
  2013年   45830篇
  2012年   60014篇
  2011年   64045篇
  2010年   38009篇
  2009年   35934篇
  2008年   60489篇
  2007年   65236篇
  2006年   65801篇
  2005年   63626篇
  2004年   61987篇
  2003年   60046篇
  2002年   58487篇
  2001年   101054篇
  2000年   103986篇
  1999年   87437篇
  1998年   24098篇
  1997年   21862篇
  1996年   21306篇
  1995年   20267篇
  1994年   18947篇
  1993年   17621篇
  1992年   68529篇
  1991年   66534篇
  1990年   65591篇
  1989年   63873篇
  1988年   58877篇
  1987年   58512篇
  1986年   55529篇
  1985年   53144篇
  1984年   39879篇
  1983年   33783篇
  1982年   20313篇
  1981年   18492篇
  1979年   37851篇
  1978年   27155篇
  1977年   23431篇
  1976年   21496篇
  1975年   23727篇
  1974年   28435篇
  1973年   27528篇
  1972年   26004篇
  1971年   24254篇
  1970年   22883篇
  1969年   21843篇
  1968年   20324篇
  1967年   18242篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
Vaskulitiden     
  相似文献   
73.
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   
74.
75.
Preimplantation genetic diagnosis (PGD) was originally developed to diagnose embryo-related genetic abnormalities for couples who present a high risk of a specific inherited disorder. Because this technology involves embryo selection, the medical, bioethical, and legal implications of the technique have been debated, particularly when it is used to select features that are not related to serious diseases. Although several initiatives have attempted to achieve regulatory harmonization, the diversity of healthcare services available and the presence of cultural differences have hampered attempts to achieve this goal. Thus, in different countries, the provision of PGD and regulatory frameworks reflect the perceptions of scientific groups, legislators, and society regarding this technology. In Brazil, several texts have been analyzed by the National Congress to regulate the use of assisted reproduction technologies. Legislative debates, however, are not conclusive, and limited information has been published on how PGD is specifically regulated. The country requires the development of new regulatory standards to ensure adequate access to this technology and to guarantee its safe practice. This study examined official documents published on PGD regulation in Brazil and demonstrated how little direct oversight of PGD currently exists. It provides relevant information to encourage reflection on a particular regulation model in a Brazilian context, and should serve as part of the basis to enable further reform of the clinical practice of PGD in the country.  相似文献   
76.
77.
78.
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   
79.
80.
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