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   2114663篇
  免费   171567篇
  国内免费   7623篇
耳鼻咽喉   27464篇
儿科学   70481篇
妇产科学   58671篇
基础医学   298099篇
口腔科学   58964篇
临床医学   192795篇
内科学   423320篇
皮肤病学   49463篇
神经病学   172013篇
特种医学   84702篇
外国民族医学   568篇
外科学   324392篇
综合类   50683篇
现状与发展   2篇
一般理论   763篇
预防医学   169346篇
眼科学   46883篇
药学   150535篇
  7篇
中国医学   3862篇
肿瘤学   110840篇
  2018年   21761篇
  2016年   19963篇
  2015年   22321篇
  2014年   31170篇
  2013年   47210篇
  2012年   59718篇
  2011年   63750篇
  2010年   39178篇
  2009年   37600篇
  2008年   59584篇
  2007年   63468篇
  2006年   64716篇
  2005年   62515篇
  2004年   60160篇
  2003年   58267篇
  2002年   55659篇
  2001年   99677篇
  2000年   102352篇
  1999年   85738篇
  1998年   25371篇
  1997年   22759篇
  1996年   23546篇
  1995年   23404篇
  1994年   21758篇
  1993年   20330篇
  1992年   70551篇
  1991年   68844篇
  1990年   66687篇
  1989年   64049篇
  1988年   58991篇
  1987年   58419篇
  1986年   54910篇
  1985年   53098篇
  1984年   40331篇
  1983年   33944篇
  1982年   21019篇
  1981年   18949篇
  1980年   17773篇
  1979年   36744篇
  1978年   26696篇
  1977年   22423篇
  1976年   20970篇
  1975年   21849篇
  1974年   25990篇
  1973年   25037篇
  1972年   23089篇
  1971年   21361篇
  1970年   19701篇
  1969年   18487篇
  1968年   17128篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
Vaskulitiden     
  相似文献   
83.
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   
84.
85.
86.
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   
87.
88.
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   
89.
90.
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