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   33160篇
  免费   3350篇
  国内免费   535篇
耳鼻咽喉   129篇
儿科学   474篇
妇产科学   394篇
基础医学   1462篇
口腔科学   692篇
临床医学   7227篇
内科学   2095篇
皮肤病学   146篇
神经病学   1353篇
特种医学   372篇
外国民族医学   1篇
外科学   4026篇
综合类   4094篇
现状与发展   1篇
一般理论   23篇
预防医学   6659篇
眼科学   198篇
药学   2565篇
  76篇
中国医学   4063篇
肿瘤学   995篇
  2025年   11篇
  2024年   707篇
  2023年   1226篇
  2022年   1412篇
  2021年   1937篇
  2020年   2183篇
  2019年   1951篇
  2018年   1705篇
  2017年   1801篇
  2016年   1602篇
  2015年   1503篇
  2014年   2280篇
  2013年   2881篇
  2012年   1893篇
  2011年   2009篇
  2010年   1529篇
  2009年   1368篇
  2008年   1413篇
  2007年   1337篇
  2006年   1196篇
  2005年   857篇
  2004年   716篇
  2003年   700篇
  2002年   473篇
  2001年   421篇
  2000年   396篇
  1999年   255篇
  1998年   236篇
  1997年   203篇
  1996年   183篇
  1995年   126篇
  1994年   94篇
  1993年   77篇
  1992年   53篇
  1991年   43篇
  1990年   58篇
  1989年   33篇
  1988年   29篇
  1987年   20篇
  1986年   17篇
  1985年   25篇
  1984年   9篇
  1983年   10篇
  1982年   11篇
  1981年   8篇
  1980年   13篇
  1979年   6篇
  1978年   5篇
  1977年   5篇
  1974年   8篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
The fragility index (FI), the number of events the statistical significance a result depends on, and the number of patients lost to follow-up are important parameters for interpreting randomised clinical trial results. We evaluated these two parameters in randomised controlled trials in anaesthesiology. For this, we performed a systematic search of the medical literature, seeking articles reporting on anaesthesiology trials with a statistically significant difference in the primary outcome and published in the top five general medicine journals, or the top 15 anaesthesiology journals. We restricted the analysis to trials reporting clinically important primary outcome measures. The search identified 139 articles, 35 published in general medicine journals and 104 in anaesthesiology journals. The median (inter-quartile range) sample size was 150 (70–300) patients. The FI was 4 (2–17) and 3 (2–7), and the number of patients lost to follow-up was 0 (0–18) and 0 (0–6) patients in trials published in general medicine and anaesthesiology journals, respectively. The number of patients lost to follow-up exceeded the FI in 41 and 27% in trials in general medicine journals and anaesthesiology journals, respectively. The FI positively correlated with sample size and number of primary outcome events, and negatively correlated with the reported P-values. The results of this systematic review suggest that statistically significant differences in randomised controlled anaesthesiology trials are regularly fragile, implying that the primary outcome status of patients lost to follow-up could possibly have changed the reported effect.  相似文献   
72.
基于数据的证候规范的信息研究   总被引:1,自引:0,他引:1  
以讨论证候规范信息研究中数据客观化解决的思路与方法为主题,通过对基于数据的意义、数据客观化的解决方案、证候规范研究对学习技术的需求等问题的讨论,强调证候规范研究数据客观性的重要,界定中医数据客观性的意义,提出基于数据的信息研究方案,论证了采用支持向量机方法(Supporter Vector Machine,简记SVM)的优势。认为“有效”和“普遍”是中医学数据客观性的主要依据,数据的客观化是中医证候规范研究的重要前提。  相似文献   
73.
It is now well established that many general anesthetics have a variety of effects on the developing brain in animal models. In contrast, human cohort studies show mixed evidence for any association between neurobehavioural outcome and anesthesia exposure in early childhood. In spite of large volumes of research, it remains very unclear if the animal studies have any clinical relevance; or indeed how, or if, clinical practice needs to be altered. Answering these questions is of great importance given the huge numbers of young children exposed to general anesthetics. A recent meeting in Genoa brought together researchers and clinicians to map a path forward for future clinical studies. This paper describes these discussions and conclusions. It was agreed that there is a need for large, detailed, prospective, observational studies, and for carefully designed trials. It may be impossible to design or conduct a single study to completely exclude the possibility that anesthetics can, under certain circumstances, produce long‐term neurobehavioural changes in humans; however , observational studies will improve our understanding of which children are at greatest risk, and may also suggest potential underlying etiologies, and clinical trials will provide the strongest evidence to test the effectiveness of different strategies or anesthetic regimens with respect to better neurobehavioral outcome.  相似文献   
74.
75.
Previous studies suggest that quantifying donor‐reactive memory T cells prior to kidney transplantation by interferon gamma enzyme‐linked immunosorbent spot assay (IFNγELISPOT) can assist in assessing risk of posttransplant allograft injury. Herein, we report an analysis of IFNγELISPOT results from the multicenter, Clinical Trials in Organ Transplantation‐01 observational study of primary kidney transplant recipients treated with heterogeneous immunosuppression. Within the subset of 176 subjects with available IFNγELISPOT results, pretransplant IFNγELISPOT positivity surprisingly did not correlate with either the incidence of acute rejection (AR) or estimated glomerular filtration rate (eGFR) at 6‐ or 12‐month. These unanticipated results prompted us to examine potential effect modifiers, including the use of T cell‐depleting, rabbit anti‐thymocyte globulin (ATG). Within the no‐ATG subset, IFNγELISPOTneg subjects had higher 6‐ and 12‐month eGFRs than IFNγELISPOTpos subjects, independent of biopsy‐proven AR, peak PRA, human leukocyte antigen mismatches, African‐American race, donor source, and recipient age or gender. In contrast, IFNγELISPOT status did not correlate with posttransplant eGFR in subjects given ATG. Our data confirm an association between pretransplant IFNγELISPOT positivity and lower posttransplant eGFR, but only in patients who do not receive ATG induction. Controlled studies are needed to test the hypothesis that ATG induction is preferentially beneficial to transplant candidates with high frequencies of donor‐reactive memory T cells.  相似文献   
76.
77.
78.
79.
80.
完善全面的人事信息系统是现代化医学科研院所高效运转的基础。本文以分析医学科研院所人事信息特点为基础,指出了医学科研院所人事信息管理现状、问题及困境,并根据实践经验提出了具体解决路径。  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