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   1209961篇
  免费   79607篇
  国内免费   2643篇
耳鼻咽喉   14602篇
儿科学   42175篇
妇产科学   32412篇
基础医学   169106篇
口腔科学   29846篇
临床医学   105224篇
内科学   231094篇
皮肤病学   24227篇
神经病学   98911篇
特种医学   48519篇
外国民族医学   305篇
外科学   185087篇
综合类   26828篇
一般理论   419篇
预防医学   98674篇
眼科学   25929篇
药学   83650篇
  3篇
中国医学   2666篇
肿瘤学   72534篇
  2018年   33692篇
  2017年   26694篇
  2016年   30906篇
  2015年   11970篇
  2014年   15743篇
  2013年   23713篇
  2012年   37050篇
  2011年   53788篇
  2010年   38236篇
  2009年   30166篇
  2008年   51183篇
  2007年   56348篇
  2006年   32864篇
  2005年   33822篇
  2004年   34552篇
  2003年   35059篇
  2002年   31739篇
  2001年   47732篇
  2000年   49108篇
  1999年   40914篇
  1998年   11767篇
  1997年   10696篇
  1996年   10563篇
  1995年   10165篇
  1994年   9512篇
  1993年   8859篇
  1992年   32692篇
  1991年   31953篇
  1990年   31496篇
  1989年   30289篇
  1988年   27515篇
  1987年   27653篇
  1986年   25783篇
  1985年   24921篇
  1984年   18708篇
  1983年   15815篇
  1982年   9637篇
  1981年   8607篇
  1979年   17152篇
  1978年   12425篇
  1977年   10482篇
  1976年   9980篇
  1975年   10322篇
  1974年   12530篇
  1973年   12011篇
  1972年   11032篇
  1971年   10237篇
  1970年   9525篇
  1969年   8848篇
  1968年   8215篇
排序方式: 共有10000条查询结果,搜索用时 375 毫秒
41.
42.
43.
44.
45.
Vaskulitiden     
  相似文献   
46.
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   
47.
48.
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   
49.
50.
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   
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