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   1825271篇
  免费   128326篇
  国内免费   4150篇
耳鼻咽喉   23608篇
儿科学   59204篇
妇产科学   49188篇
基础医学   259940篇
口腔科学   53112篇
临床医学   158885篇
内科学   361655篇
皮肤病学   41946篇
神经病学   141704篇
特种医学   67405篇
外国民族医学   243篇
外科学   271441篇
综合类   39598篇
现状与发展   4篇
一般理论   553篇
预防医学   140440篇
眼科学   43729篇
药学   133856篇
  9篇
中国医学   4957篇
肿瘤学   106270篇
  2021年   14654篇
  2019年   15676篇
  2018年   23698篇
  2017年   17611篇
  2016年   19037篇
  2015年   21628篇
  2014年   29164篇
  2013年   42497篇
  2012年   60639篇
  2011年   63829篇
  2010年   36919篇
  2009年   33717篇
  2008年   58329篇
  2007年   62120篇
  2006年   62303篇
  2005年   59219篇
  2004年   56925篇
  2003年   53924篇
  2002年   51902篇
  2001年   95159篇
  2000年   97443篇
  1999年   79870篇
  1998年   20357篇
  1997年   17735篇
  1996年   17837篇
  1995年   17133篇
  1994年   15652篇
  1993年   14368篇
  1992年   59114篇
  1991年   56836篇
  1990年   54537篇
  1989年   52139篇
  1988年   47467篇
  1987年   46200篇
  1986年   43540篇
  1985年   41231篇
  1984年   30206篇
  1983年   25665篇
  1982年   14316篇
  1979年   26567篇
  1978年   18260篇
  1977年   15584篇
  1976年   14515篇
  1975年   15324篇
  1974年   18606篇
  1973年   17933篇
  1972年   16637篇
  1971年   15400篇
  1970年   14313篇
  1969年   13454篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Sinus venosus atrial septal defect (SV‐ASD) usually coexists with partial anomalous pulmonary vein connection (PAPVC). It is a difficult diagnosis in transthoracic echocardiography (TTE) due to eccentric position of defects. We present a rare case of atypical anatomical variation in PAPVC, which was never described before. Two right pulmonary veins drained into superior vena cava, which overrode SV‐ASD and interatrial septum, a third pulmonary vein into the right atrium. Complete diagnosis could not be set after TTE, nor transesophageal echocardiography, whereas angio‐CT was finally conclusive. This diagnostic approach allowed the surgical planning.  相似文献   
5.
In the current immunosuppressive therapy era, vessel thrombosis is the most common cause of early graft loss after renal transplantation. The prevalence of IgA anti–β2-glycoprotein I antibodies (IgA-aB2GPI-ab) in patients on dialysis is elevated (>30%), and these antibodies correlate with mortality and cardiovascular morbidity. To evaluate the effect of IgA-aB2GPI-ab in patients with transplants, we followed all patients transplanted from 2000 to 2002 in the Hospital 12 de Octubre prospectively for 10 years. Presence of IgA-aB2GPI-ab in pretransplant serum was examined retrospectively. Of 269 patients, 89 patients were positive for IgA-aB2GPI-ab (33%; group 1), and the remaining patients were negative (67%; group 2). Graft loss at 6 months post-transplant was significantly higher in group 1 (10 of 89 versus 3 of 180 patients in group 2; P=0.002). The most frequent cause of graft loss was thrombosis of the vessels, which was observed only in group 1 (8 of 10 versus 0 of 3 patients in group 2; P=0.04). Multivariate analysis showed that the presence of IgA-aB2GPI-ab was an independent risk factor for early graft loss (P=0.04) and delayed graft function (P=0.04). There were no significant differences regarding patient survival between the two groups. Graft survival was similar in both groups after 6 months. In conclusion, patients with pretransplant IgA-aB2GPI-ab have a high risk of early graft loss caused by thrombosis and a high risk of delayed graft function. Therefore, pretransplant IgA-aB2GPI-ab may have a detrimental effect on early clinical outcomes after renal transplantation.  相似文献   
6.
7.
8.
9.
10.
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   
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