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   158600篇
  免费   47783篇
  国内免费   5513篇
耳鼻咽喉   2300篇
儿科学   5090篇
妇产科学   1795篇
基础医学   25970篇
口腔科学   6397篇
临床医学   23159篇
内科学   35092篇
皮肤病学   8417篇
神经病学   17735篇
特种医学   5339篇
外国民族医学   53篇
外科学   22211篇
综合类   10841篇
现状与发展   21篇
一般理论   44篇
预防医学   9289篇
眼科学   4229篇
药学   13979篇
  67篇
中国医学   5121篇
肿瘤学   14747篇
  2024年   262篇
  2023年   1273篇
  2022年   3288篇
  2021年   5408篇
  2020年   7939篇
  2019年   13498篇
  2018年   12957篇
  2017年   13759篇
  2016年   14478篇
  2015年   15539篇
  2014年   16330篇
  2013年   16258篇
  2012年   10312篇
  2011年   10703篇
  2010年   12888篇
  2009年   8315篇
  2008年   6386篇
  2007年   5118篇
  2006年   5207篇
  2005年   4836篇
  2004年   3505篇
  2003年   3252篇
  2002年   2866篇
  2001年   2604篇
  2000年   2509篇
  1999年   2357篇
  1998年   1347篇
  1997年   1291篇
  1996年   998篇
  1995年   938篇
  1994年   786篇
  1993年   502篇
  1992年   640篇
  1991年   545篇
  1990年   511篇
  1989年   447篇
  1988年   405篇
  1987年   338篇
  1986年   277篇
  1985年   233篇
  1984年   153篇
  1983年   103篇
  1982年   57篇
  1981年   65篇
  1980年   40篇
  1979年   76篇
  1978年   41篇
  1976年   22篇
  1974年   43篇
  1973年   26篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
53.
54.
黄圣松  余敏斌 《眼科学报》2003,19(4):227-231,243
近年来,内窥镜下手术在眼科的应用有了很大进展,并且逐渐展现出其创伤小、并发症少、直视下操作、安全有效的优点。眼内窥镜联合激光可应用于青光眼前房角手术、青光眼睫状体光凝术、周边部视网膜玻璃体手术等等;另外泪道内窥镜在泪器疾病中的应用、鼻内窥镜在鼻眼相关手术中的应用也有很大的发展。眼内窥镜的应用开创了眼科微创手术时代。本文就眼用内窥镜的基本工作原理、应用现状和发展前景进行综述。  相似文献   
55.
Abstract – Traumatic dental injuries often occur to the teeth and their supporting tissues and they are the main reasons for emergency visit to a dental clinic. Management of a fracture depends on its position and the extent of root involvement. Horizontal root fractures are not seen frequently and the treatment consists of reduction and long‐term rigid fixation of the coronal segment. The present case demonstrates the successful management of two horizontally fractured maxillary central incisors with a follow‐up period of 9 months.  相似文献   
56.
Selecting an appropriate working correlation structure is pertinent to clustered data analysis using generalized estimating equations (GEE) because an inappropriate choice will lead to inefficient parameter estimation. We investigate the well‐known criterion of QIC for selecting a working correlation structure, and have found that performance of the QIC is deteriorated by a term that is theoretically independent of the correlation structures but has to be estimated with an error. This leads us to propose a correlation information criterion (CIC) that substantially improves the QIC performance. Extensive simulation studies indicate that the CIC has remarkable improvement in selecting the correct correlation structures. We also illustrate our findings using a data set from the Madras Longitudinal Schizophrenia Study. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   
57.
目的 研究腹腔内注射三氧化二砷(arsenic trioxide,As2O3)对小鼠CO2气腹下肝癌H22转移的影响. 方法 昆明鼠40只(清洁级),中腹部穿刺置入1 mm套管针,自套管针注入1×106肿瘤细胞后,建立CO2气腹,压力8 mm Hg,时间30 min.术后随机分4组,每组10只,分别腹腔内注入生理盐水,1 ml;As2O3(2 mg/kg),1 ml;As2O3(4 mg/kg),1 ml;As2O3(4mg/kg)+肝素(10 U/ml),共1 ml.气腹后第3、7天测量肿瘤黏附因子(CD44)、血管内皮生长因子(vascular endothelial growth factor,VEGF)的变化;比较各组生存状态、腹围、体重变化及转移瘤直径.结果 气腹后第3、7天,与对照组相比,各As2O3组CD44、VEGF表达均明显降低(P<0.05).2个高剂量组的气腹后第3天VEGF、第7天CD44比低剂量组降低明显(P<0.05).4组戳口种植率分别为9/10、8/10、7/10、6/10,差异无显著性(x2=2.667,P=0.446). 结论 As2O3对CO2气腹腹腔镜肿瘤生长转移有抑制作用.  相似文献   
58.
59.
60.
Context The assessment of ethical problem solving in medicine has been controversial and challenging. The purposes of this study were: (i) to create a new instrument to measure doctors’ decisions on and reasoning approach towards resolving ethical problems; (ii) to evaluate the scores generated by the new instrument for their reliability and validity, and (iii) to compare doctors’ ethical reasoning abilities between countries and among medical students, residents and experts. Methods This study used 15 clinical vignettes and the think‐aloud method to identify the processes and components involved in ethical problem solving. Subjects included volunteer ethics experts, postgraduate Year 2 residents and pre‐clerkship medical students. The interview data were coded using the instruments of the decision score and Ethical Reasoning Inventory (ERI). The ERI assessed the quality of ethical reasoning for a particular case (Part I) and for an individual globally across all the vignettes (Part II). Results There were 17 Canadian and 32 Taiwanese subjects. Based on the Canadian standard, the decision scores between Taiwanese and Canadian subjects differed significantly, but made no discrimination among the three levels of expertise. Scores on the ERI Parts I and II, which reflect doctors’ reasoning quality, differed between countries and among different levels of expertise in Taiwan, providing evidence of construct validity. In addition, experts had a greater organised knowledge structure and considered more relevant variables in the process of arriving at ethical decisions than did residents or students. The reliability of ERI scores was 0.70–0.99 on Part I and 0.75–0.80 on Part II. Conclusions Expertise in solving ethical problems could not be differentiated by the decisions made, but could be differentiated according to the reasoning used to make those decisions. The difference between Taiwanese and Canadian experts suggests that cultural considerations come into play in the decisions that are made in the course of providing humane care to patients.  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