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   46423篇
  免费   2839篇
  国内免费   473篇
耳鼻咽喉   893篇
儿科学   596篇
妇产科学   631篇
基础医学   7642篇
口腔科学   1118篇
临床医学   3668篇
内科学   8873篇
皮肤病学   1660篇
神经病学   3443篇
特种医学   2994篇
外国民族医学   1篇
外科学   6283篇
综合类   270篇
现状与发展   1篇
一般理论   7篇
预防医学   2089篇
眼科学   1044篇
药学   4258篇
中国医学   577篇
肿瘤学   3687篇
  2024年   33篇
  2023年   313篇
  2022年   1070篇
  2021年   1665篇
  2020年   773篇
  2019年   1111篇
  2018年   1381篇
  2017年   1089篇
  2016年   1578篇
  2015年   2157篇
  2014年   2548篇
  2013年   2896篇
  2012年   4262篇
  2011年   4058篇
  2010年   2406篇
  2009年   2036篇
  2008年   2831篇
  2007年   2604篇
  2006年   2372篇
  2005年   2149篇
  2004年   1711篇
  2003年   1484篇
  2002年   1314篇
  2001年   1032篇
  2000年   913篇
  1999年   663篇
  1998年   278篇
  1997年   197篇
  1996年   168篇
  1995年   124篇
  1994年   128篇
  1993年   108篇
  1992年   237篇
  1991年   254篇
  1990年   252篇
  1989年   196篇
  1988年   187篇
  1987年   206篇
  1986年   158篇
  1985年   124篇
  1984年   79篇
  1983年   72篇
  1982年   53篇
  1981年   56篇
  1979年   45篇
  1978年   58篇
  1977年   30篇
  1975年   29篇
  1974年   29篇
  1970年   29篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Recent studies have reported an association between gastroesophageal reflux disease (GERD) and atrial fibrillation (AF). The objective of the present study was to evaluate whether AF is one of the risk factors for GERD occurrence.In this hospital-based, retrospective, case–control study, the patients were classified into 2 groups. The patients diagnosed with new AF were assigned to the AF group (n = 1612); those diagnosed without AF and GERD were assigned to the control group (n = 1612). The subjects in the control group were selected from outpatients of total healthcare center without a history of AF or GERD, and matched for age and gender. We evaluated the incidence of GERD and risk factors for GERD occurrence between the 2 groups.The number of patients experiencing occurrence of GERD during the follow-up period was significantly higher in the AF group than those in the control group, respectively (129 patients vs 98 subjects, P = 0.037). The incidence of GERD was significantly higher in the AF group than in the control group by Kaplan–Meier analysis with log-rank test (P = 0.008). The AF group''s adjusted hazard ratio of GERD occurrence against that of the control group was 1.37 (95% confidence interval [CI]: 1.16–1.57; P = 0.009) according to Cox''s proportional hazard model.The presence of AF appears to increase the incidence of GERD and may be considered a risk factor for the development of GERD. Further, large prospective and cohort studies will be required to better establish the correlation of GERD with AF.  相似文献   
22.
23.
24.
25.
26.
Carbon monoxide (CO), a byproduct of heme catalysis, was shown to have potent cytoprotective and anti-inflammatory effects. In vivo recipient CO inhalation at low concentrations prevented ischemia/reperfusion (I/R) injury associated with small intestinal transplantation (SITx). This study examined whether ex vivo delivery of CO in University of Wisconsin (UW) solution could ameliorate intestinal I/R injury. Orthotopic syngenic SITx was performed in Lewis rats after 6 h cold preservation in control UW or UW that was bubbled with CO gas (0.1-5%) (CO-UW). Recipient survival with intestinal grafts preserved in 5%, but not 0.1%, CO-UW improved to 86.7% (13/15) from 53% (9/17) with control UW. At 3 h after SITx, grafts stored in 5% CO-UW showed improved intestinal barrier function, less mucosal denudation and reduced inflammatory mediator upregulation compared to those in control UW. Preservation in CO-UW associated with reduced vascular resistance (end preservation), increased graft cyclic guanosine monophosphate levels (1 h), and improved graft blood flow (1 h). Protective effects of CO-UW were reversed by ODQ, an inhibitor of soluble guanylyl cyclase. In vitro culture experiment also showed better preservation of vascular endothelial cells with CO-UW. The study suggests that ex vivo CO delivery into UW solution would be a simple and innovative therapeutic strategy to prevent transplant-induced I/R injury.  相似文献   
27.
Generally, a computed tomography scan is conducted for the diagnosis of stroke in the emergency department, because these scans are easier and faster in the detection of stroke. If there are no signs of hemorrhage on computed tomography scan, an ischemic stroke is diagnosed and treated accordingly. A magnetic resonance imaging scan may be taken in order to verify ischemic stroke. This process may lead to improper treatment and is time consuming. To address this situation, case studies are presented in which magnetic resonance imaging diffusion-weighted imaging and gradient recalled echo were performed to detect hemorrhagic and ischemic stroke and particularly, subarachnoid hemorrhage, which is undetectable with a computed tomography scan.  相似文献   
28.
29.
30.
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