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   4957篇
  免费   329篇
  国内免费   31篇
耳鼻咽喉   29篇
儿科学   128篇
妇产科学   99篇
基础医学   887篇
口腔科学   60篇
临床医学   506篇
内科学   1086篇
皮肤病学   73篇
神经病学   512篇
特种医学   308篇
外国民族医学   1篇
外科学   661篇
综合类   33篇
预防医学   208篇
眼科学   69篇
药学   300篇
中国医学   24篇
肿瘤学   333篇
  2022年   29篇
  2021年   64篇
  2020年   41篇
  2019年   68篇
  2018年   75篇
  2017年   76篇
  2016年   80篇
  2015年   97篇
  2014年   111篇
  2013年   166篇
  2012年   198篇
  2011年   209篇
  2010年   146篇
  2009年   193篇
  2008年   237篇
  2007年   249篇
  2006年   256篇
  2005年   199篇
  2004年   213篇
  2003年   183篇
  2002年   257篇
  2001年   225篇
  2000年   214篇
  1999年   203篇
  1998年   88篇
  1997年   76篇
  1996年   60篇
  1995年   43篇
  1994年   46篇
  1993年   32篇
  1992年   75篇
  1991年   68篇
  1990年   53篇
  1989年   79篇
  1988年   65篇
  1987年   56篇
  1986年   62篇
  1985年   63篇
  1984年   39篇
  1983年   49篇
  1982年   33篇
  1981年   28篇
  1980年   31篇
  1979年   29篇
  1978年   21篇
  1977年   23篇
  1975年   27篇
  1933年   23篇
  1926年   19篇
  1922年   18篇
排序方式: 共有5317条查询结果,搜索用时 15 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.
Tauchunfälle     
Notfall + Rettungsmedizin - Tauchunfälle sind vergleichsweise selten und stellen (Erst‑)Helfer vor besondere Herausforderungen. Sie müssen schnell und kompetent behandelt werden, da...  相似文献   
6.
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   
7.
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   
8.
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   
9.
10.
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