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   1446084篇
  免费   119501篇
  国内免费   6622篇
耳鼻咽喉   18506篇
儿科学   46344篇
妇产科学   38944篇
基础医学   198657篇
口腔科学   40224篇
临床医学   127546篇
内科学   305475篇
皮肤病学   35459篇
神经病学   119123篇
特种医学   57946篇
外国民族医学   275篇
外科学   223779篇
综合类   32101篇
现状与发展   2篇
一般理论   445篇
预防医学   117416篇
眼科学   30513篇
药学   101347篇
  5篇
中国医学   2736篇
肿瘤学   75364篇
  2019年   11680篇
  2018年   17686篇
  2017年   13150篇
  2016年   15095篇
  2015年   16851篇
  2014年   22987篇
  2013年   34347篇
  2012年   44324篇
  2011年   47459篇
  2010年   28711篇
  2009年   27010篇
  2008年   43255篇
  2007年   46079篇
  2006年   46653篇
  2005年   45197篇
  2004年   42622篇
  2003年   41306篇
  2002年   39019篇
  2001年   69073篇
  2000年   71377篇
  1999年   59230篇
  1998年   17166篇
  1997年   15304篇
  1996年   16277篇
  1995年   16445篇
  1994年   15267篇
  1993年   14302篇
  1992年   48117篇
  1991年   46610篇
  1990年   44722篇
  1989年   42444篇
  1988年   39258篇
  1987年   38593篇
  1986年   36389篇
  1985年   35076篇
  1984年   26690篇
  1983年   22349篇
  1982年   13965篇
  1981年   12562篇
  1980年   11823篇
  1979年   23831篇
  1978年   17238篇
  1977年   14550篇
  1976年   13349篇
  1975年   13954篇
  1974年   16363篇
  1973年   15699篇
  1972年   14427篇
  1971年   13305篇
  1970年   12138篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
61.
62.
Behçet disease is a complex, multisystem disease characterized by recurrent oral and genital ulcerations. It rarely occurs in infants or children. Neonatal Behçet disease has been reported in infants whose ulcers resolve at or before 9 weeks of age. Few cases of neonatal Behçet disease persisting into childhood have previously been reported. We report the case of a 1‐month‐old infant who presented with severe recurrent genital ulcerations and at 6 months developed recurrent oral ulcerations. Her orogenital ulcerations continue to recur. Human leukocyte antigen testing revealed HLA‐B51 and B44 positivity. This is a case of pediatric Behçet disease in the neonatal period. Behçet disease should be considered in the differential diagnosis of recurrent genital and oral ulcerations in infants and children.  相似文献   
63.
64.
65.
66.
67.
68.
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   
69.
The present study aimed at measuring seropositivities for infection by Ascaris suum and Toxocara canis using the excretory/secretory (E/S) antigens from Ascaris suum (AES) and Toxocara canis (TES) within an indigenous population. In addition, quantification of cytokine expressions in peripheral blood cells was determined. A total of 50 Warao indigenous were included; of which 43 were adults and seven children. In adults, 44.1% were seropositive for both parasites; whereas children had only seropositivity to one or the other helminth. For ascariosis, the percentage of AES seropositivity in adults and children was high; 23.3% and 57.1%, respectively. While that for toxocariosis, the percentage of TES seropositivity in adults and children was low; 9.3% and 14.3%, respectively. The percentage of seronegativity was comparable for AES and TES antigens in adults (27.9%) and children (28.6%). When positive sera were analyzed by Western blotting technique using AES antigens; three bands of 97.2, 193.6 and 200.2 kDas were mostly recognized. When the TES antigens were used, nine major bands were mostly identified; 47.4, 52.2, 84.9, 98.2, 119.1, 131.3, 175.6, 184.4 and 193.6 kDas. Stool examinations showed that Blastocystis hominis, Hymenolepis nana and Entamoeba coli were the most commonly observed intestinal parasites. Quantification of cytokines IFN-γ, IL-2, IL-6, TGF-β, TNF-α, IL-10 and IL-4 expressions showed that there was only a significant increased expression of IL-4 in indigenous with TES seropositivity (p < 0.002). Ascaris and Toxocara seropositivity was prevalent among Warao indigenous.  相似文献   
70.
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