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   5684篇
  免费   423篇
  国内免费   63篇
耳鼻咽喉   46篇
儿科学   151篇
妇产科学   94篇
基础医学   943篇
口腔科学   60篇
临床医学   636篇
内科学   1093篇
皮肤病学   89篇
神经病学   520篇
特种医学   208篇
外国民族医学   1篇
外科学   726篇
综合类   328篇
预防医学   292篇
眼科学   80篇
药学   389篇
  3篇
中国医学   157篇
肿瘤学   354篇
  2023年   33篇
  2022年   83篇
  2021年   109篇
  2020年   89篇
  2019年   83篇
  2018年   98篇
  2017年   107篇
  2016年   104篇
  2015年   124篇
  2014年   149篇
  2013年   228篇
  2012年   289篇
  2011年   285篇
  2010年   215篇
  2009年   264篇
  2008年   320篇
  2007年   313篇
  2006年   306篇
  2005年   252篇
  2004年   255篇
  2003年   213篇
  2002年   276篇
  2001年   237篇
  2000年   231篇
  1999年   203篇
  1998年   77篇
  1997年   57篇
  1996年   40篇
  1995年   37篇
  1994年   32篇
  1993年   26篇
  1992年   71篇
  1991年   68篇
  1990年   49篇
  1989年   72篇
  1988年   58篇
  1987年   46篇
  1986年   53篇
  1985年   50篇
  1984年   34篇
  1983年   33篇
  1982年   16篇
  1980年   23篇
  1979年   26篇
  1975年   27篇
  1972年   17篇
  1967年   16篇
  1933年   23篇
  1926年   19篇
  1922年   18篇
排序方式: 共有6170条查询结果,搜索用时 0 毫秒
1.
best practice onkologie -  相似文献   
2.
3.
Health care expenditure in Germany shows clear regional differences. Such geographic variations are often seen as an indicator for inefficiency. With its homogeneous health care system, low co‐payments and uniform prices, Germany is a particularly suited example to analyse regional variations. We use data for the year 2011 on expenditure, utilization of health services and state of health in Germany's statutory health insurance system. This data, which originate from a variety of administrative sources and cover about 90% of the population, are enriched with a wealth of socio‐economic variables, data on pollutants, prices and individual preferences. State of health and demography explains 55% of the differences as measured by the standard deviation while all control variables account for a total of 72% of the differences at county level. With other measures of variation, we can account for an even greater proportion. A higher proportion of variation than usually supposed can thus be explained. Whilst this study cannot quantify inefficiencies, our results contradict the thesis that regional variations reflect inefficiency. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
4.
5.
Antibody-mediated rejection (AMR) after liver transplantation is recognized in ABO incompatible and xeno-transplantation, but its role after ABO compatible liver transplantation is controversial. We report a case of ABO compatible liver transplantation that demonstrated clinical, serological and histological signs of AMR without evidence of concurrent acute cellular rejection. AMR with persistently high titers of circulating donor specific antibodies resulted in graft injury with initial centrilobular hepatocyte necrosis, fibroedematous portal expansion mimicking biliary tract outflow obstruction, ultimately resulting in extensive bridging fibrosis. Immunofluorescence microscopy demonstrated persistent, diffuse linear C4d deposits along sinusoids and central veins. Despite intense therapeutic intervention including plasmapheresis, IVIG and rituximab, AMR led to graft failure. We present evidence that an antibody-mediated alloresponse to an ABO compatible liver graft can cause significant graft injury independent of acute cellular rejection. AMR shows distinct histologic changes including a characteristic staining profile for C4d.  相似文献   
6.
Choledochojejunostomy (CJS) is commonly used for biliary reconstruction in liver transplantation for primary sclerosing cholangitis (PSC). We alternatively performed choledochoduodenostomy (CDS) and side-to-side choledochodocholedochstomy in a large cohort of patients. Fifty-one patients with PSC, transplanted between 1988 and 2000, were analyzed retrospectively. Biliary reconstruction was CDS in 25 (49%), CJS in 20 (39%) and CC in 6 transplantations (12%). Biliary leaks occurred in the early follow-up (< or =41 days) only in CDS patients (20%). However, in the late follow-up (>4 months), stricturing of anastomosis was found once in CDS (4%) and CJS (5%). Later (>9 months), intrahepatic bile duct strictures were diagnosed in four CDS (16%), one CJS (5%) and one CC (17%) patient(s). In 48% of CDS (12/25), 60% of CJS (12/20) and 17% of CC (1/6) at least one incidence of cholangitis was observed. Overall, biliary complication rates were significantly higher in CDS (40%) than CJS (10%) and CC (17%); of those none in CC and 12% in CDS were anastomosis-related. Graft/patient survival showed no significant differences among groups. Based on our results we consider CJS the standard method for biliary reconstruction in PSC; however, in selected cases where CJS is difficult to accomplish because of previous surgery or for retransplantation, CDS may present an alternative technique.  相似文献   
7.
Increase in Power through Multivariate Analyses   总被引:6,自引:0,他引:6  
Power to detect genetic and environmental influences increases not only with sample size but also with the number of measurements through longitudinal and/or multivariate designs, if those measurements correlate with each other. Power simulations are presented for uni- through quadrivariate cases, with differing genetic and environmental parameters. Even though subject attrition is a problem for most longitudinal studies, the gain in power available may more than make up for this shortcoming in many situations. In terms of planning studies to examine genetic and environmental influences, power calculations should not only consider sample size but number of measurements on particular phenotypes and their intercorrelations.  相似文献   
8.
9.
10.
【摘要】 目的 :探讨羊水粪染与羊膜腔感染的关系。方法 :选择未临产且胎膜完整的剖宫产产妇 5 6例 ,根据术中所见羊水性状分为羊水清亮组、羊水Ⅰ~II度粪染组和羊水III度粪染组。于剖宫产术中取羊水用双抗体夹心ELISA法测IL 6含量 ,取胎盘胎膜做病理检查以了解有无炎性细胞浸润 ,并记录新生儿Apgar评分 ,观察产妇术后有无产褥感染。结果 :3组羊水中IL 6含量差异无显著性 ,3组胎盘标本病理检查示炎性细胞浸润之差异亦无显著性 ,而羊水粪染组新生儿窒息发生率较清亮组明显增加 (P <0 .0 5 )。结论 :羊水粪染尤其是III度粪染是胎儿窘迫的标志 ,而与羊膜腔感染无明显相关性。  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