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   32591篇
  免费   1688篇
  国内免费   87篇
耳鼻咽喉   343篇
儿科学   1091篇
妇产科学   824篇
基础医学   4299篇
口腔科学   514篇
临床医学   5183篇
内科学   5834篇
皮肤病学   517篇
神经病学   3233篇
特种医学   630篇
外科学   2946篇
综合类   411篇
一般理论   40篇
预防医学   3969篇
眼科学   390篇
药学   1910篇
  4篇
中国医学   54篇
肿瘤学   2174篇
  2024年   86篇
  2023年   181篇
  2022年   335篇
  2021年   675篇
  2020年   425篇
  2019年   722篇
  2018年   801篇
  2017年   543篇
  2016年   557篇
  2015年   733篇
  2014年   1017篇
  2013年   1520篇
  2012年   2301篇
  2011年   2405篇
  2010年   1328篇
  2009年   1118篇
  2008年   2180篇
  2007年   2175篇
  2006年   2226篇
  2005年   2072篇
  2004年   1961篇
  2003年   1868篇
  2002年   1748篇
  2001年   299篇
  2000年   224篇
  1999年   342篇
  1998年   361篇
  1997年   325篇
  1996年   295篇
  1995年   252篇
  1994年   245篇
  1993年   234篇
  1992年   209篇
  1991年   164篇
  1990年   166篇
  1989年   153篇
  1988年   131篇
  1987年   126篇
  1986年   121篇
  1985年   126篇
  1984年   157篇
  1983年   173篇
  1982年   179篇
  1981年   156篇
  1980年   144篇
  1979年   95篇
  1978年   73篇
  1977年   79篇
  1976年   64篇
  1974年   70篇
排序方式: 共有10000条查询结果,搜索用时 109 毫秒
91.
Hoferellus azevedoi n. sp. was found in the urinary bladder of Chaetobranchus flavescens Heckel, 1840 from the Arari River on Marajó Island in Pará, Brazil. This is the first record of a species of the genus Hoferellus in a host from the Brazilian Amazon region. The new species has disporous and polysporous plasmodia, which vary in size and shape, with some being found adhered to the epithelium of the urinary bladder, and others floating in the liquid. The mature spores are sub-spherical in the sutural view, with a number of peripheral projections around the whole surface of the spore. In the sutural view, the spores are 5.3 ± 0.2 (5.2–5.6) μm in length and 7.0 ± 0.7 (6.3–7.7) μm in width, with two piriform polar capsules of equal size, 2.5 ± 0.2 (2.3–2.8) μm long and 1.8 ± 0.2 (1.6–2.0) μm wide. Based on a partial (1312 bps) sequence of the SSU rDNA gene, Hoferellus azevedoi n. sp. was distinguished from all the other myxozoan species deposited in GenBank. Phylogenetically, based on Bayesian inference and p-distances, the new species was allocated to the “Freshwater Urinary-Bladder” clade, together with other myxozoan parasites of the excretory system. Based on the morphological data, supported by the partial sequence of the SSU rDNA gene, we describe a new species of myxozoan, Hoferellus azevedoi n. sp.  相似文献   
92.
93.
94.
95.
96.
97.
98.
99.

Background and objectives

Alemtuzumab is a humanized anti-CD52 monoclonal antibody used as induction in kidney transplantation (KTX) since 2003. Few studies have evaluated long-term outcomes of this agent or changes in outcomes over time.

Design, setting, participants, & measurements

A retrospective cohort study was performed examining United States registry data from 2003 to 2014 of primary KTX recipients receiving induction with alemtuzumab (AZ; n=5521) or antithymocyte globulin (ATG; n=8504) and maintenance immunosuppression with tacrolimus and mycophenolate mofetil and early withdrawal of steroids. The primary outcome was overall death-censored graft survival (DCGS), and secondary outcomes were overall patient survival and 1-year acute rejection. Multivariate models were fit with donor, recipient, and transplant covariates. Because poorer outcomes with AZ may occur from a learning curve impact with the use of a new medication, transplant year was categorized into three time periods to evaluate outcomes over time (2003–2005, 2006–2008, ≥2009), and an interaction term of induction type with transplant year category was included in all models to test for era impacts.

Results

On multivariate analysis of DCGS there was a significant interaction between AZ and era (P<0.001). AZ was significantly associated with inferior DCGS in the earliest 2003–2005 era (adjusted hazard ratio [aHR], 2.21; 95% confidence interval [95% CI], 1.72 to 2.84) but not in the middle 2006–2008 era (aHR, 1.14; 95% CI, 0.96 to 1.36) or the most recent 2009–2014 era (aHR, 1.08; 95% CI, 0.90 to 1.29) compared with ATG. Risk-adjusted patient survival (aHR, 1.32; 95% CI, 1.08 to 1.61; aHR, 1.26; 95% CI, 1.09 to 1.46; and aHR, 1.10; 95% CI, 0.93 to 1.29 by era, respectively) and acute rejection (adjusted odds ratio [aOR], 1.17; 95% CI, 0.96 to 1.42; aOR, 0.94; 95% CI, 0.82 to 1.07; aOR, 0.89; 95% CI, 0.81 to 0.98 by era, respectively) with AZ was comparable with ATG in the most recent era; however, there was no significant interaction with time (P=0.13 and P=0.06, respectively).

Conclusions

Current alemtuzumab utilization is associated with comparable graft and patient survival and acute rejection compared with ATG. Graft survival with alemtuzumab has improved over time.  相似文献   
100.
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