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   878693篇
  免费   73277篇
  国内免费   3467篇
耳鼻咽喉   13030篇
儿科学   24886篇
妇产科学   25427篇
基础医学   126102篇
口腔科学   25873篇
临床医学   77808篇
内科学   166632篇
皮肤病学   17223篇
神经病学   70837篇
特种医学   35876篇
外国民族医学   186篇
外科学   138148篇
综合类   27902篇
现状与发展   8篇
一般理论   265篇
预防医学   67824篇
眼科学   21043篇
药学   66833篇
  13篇
中国医学   2582篇
肿瘤学   46939篇
  2018年   8119篇
  2015年   8675篇
  2014年   12359篇
  2013年   17818篇
  2012年   24389篇
  2011年   25539篇
  2010年   14873篇
  2009年   13919篇
  2008年   23780篇
  2007年   25793篇
  2006年   25680篇
  2005年   25439篇
  2004年   24460篇
  2003年   23577篇
  2002年   22549篇
  2001年   36279篇
  2000年   37001篇
  1999年   31304篇
  1998年   9096篇
  1997年   8316篇
  1996年   8146篇
  1995年   8267篇
  1994年   7918篇
  1992年   26890篇
  1991年   26316篇
  1990年   25824篇
  1989年   24877篇
  1988年   23375篇
  1987年   22997篇
  1986年   21853篇
  1985年   21229篇
  1984年   16404篇
  1983年   13996篇
  1982年   8843篇
  1981年   8187篇
  1980年   7633篇
  1979年   16710篇
  1978年   12085篇
  1977年   10145篇
  1976年   9299篇
  1975年   10116篇
  1974年   12630篇
  1973年   12131篇
  1972年   11539篇
  1971年   10679篇
  1970年   10204篇
  1969年   9907篇
  1968年   8899篇
  1967年   8219篇
  1966年   7644篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
The Earth’s mean surface temperature is already approximately 1.1°C higher than pre-industrial levels. Exceeding a mean 1.5°C rise by 2050 will make global adaptation to the consequences of climate change less possible. To protect public health, anaesthesia providers need to reduce the contribution their practice makes to global warming. We convened a Working Group of 45 anaesthesia providers with a recognised interest in sustainability, and used a three-stage modified Delphi consensus process to agree on principles of environmentally sustainable anaesthesia that are achievable worldwide. The Working Group agreed on the following three important underlying statements: patient safety should not be compromised by sustainable anaesthetic practices; high-, middle- and low-income countries should support each other appropriately in delivering sustainable healthcare (including anaesthesia); and healthcare systems should be mandated to reduce their contribution to global warming. We set out seven fundamental principles to guide anaesthesia providers in the move to environmentally sustainable practice, including: choice of medications and equipment; minimising waste and overuse of resources; and addressing environmental sustainability in anaesthetists’ education, research, quality improvement and local healthcare leadership activities. These changes are achievable with minimal material resource and financial investment, and should undergo re-evaluation and updates as better evidence is published. This paper discusses each principle individually, and directs readers towards further important references.  相似文献   
52.
We studied the prognostic value of primary tumor sidedness in metastatic colorectal cancer over time and across treatment lines. Population data on synchronous metastatic colorectal cancer patients were extracted from the Netherlands Cancer Registry and SEER database. Pubmed, EMBASE and Cochrane library were searched for prospective studies on metastatic colorectal cancer to conduct a meta-analysis. Inclusion criteria consisted of metastatic disease, systemic treatment with palliative intent and specification of primary tumor location. Data were pooled using a random-effects model. For the population-based data, multivariable Cox models were constructed. The Grambsch-Therneau test was conducted to evaluate the potential time-varying nature of sidedness. Meta-regression incorporating treatment-line as variable was conducted to test the pre-specified hypothesis that the prognostic value of sidedness varies over time. Analysis of 12 885 and 16 160 synchronous metastatic colorectal cancer patients registered in the Netherlands Cancer Registry and SEER database, respectively, indicated a time-varying prognostic value of sidedness (P < .01). Thirty-one studies were selected for the meta-analysis (9558 patients for overall survival analysis). Pooled univariable hazard ratioleft-sided/right-sided for overall survival was 0.71 (95% CI: 0.65-0.76) in 1st-line, 0.76 (0.54-1.06) in 2nd-line and 1.01 (0.86-1.19) in 3rd-line studies. Hazard ratios were significantly influenced by treatment line (P = .035). The prognostic value of sidedness of the primary tumor in metastatic colorectal cancer patients treated with palliative systemic therapy decreases over time since diagnosis, suggesting that sidedness may not be a useful stratification factor in late-line trials. This decrease in prognostic value should be taken into account when providing prognostic information to patients.  相似文献   
53.
54.
Journal of Thrombosis and Thrombolysis - Over the last few years data from our group have indicated that α-synuclein is important in development of immune cells as well as potentially...  相似文献   
55.
56.
Structured data sets can be created from cytology reports without the addition of synoptic reports using either natural language processing or minor changes to laboratory information systems structure.;  相似文献   
57.
在高职高专内科护理教学中,利用CIPP多元评价体系,研究探讨案例教学法提高教学质量的可行性和效果。  相似文献   
58.
59.
目的 探讨糖尿病前期的中医证型及证素分布特点。方法 检索中国知网、万方及维普三大数据库中收录的自建库以来有关糖尿病前期证型的临床研究文献,对中医证型进行规范整理,建立数据库,提取证素,运用数据挖掘技术中的关联分析、聚类分析探究证素分布规律。结果 共纳入10篇文献,总有效病例1620例,证型经规范处理后整理为18个,主要证型为脾虚痰湿证。共提取证素13个,主要病位证素为脾,主要病性证素为气虚、湿和痰,关联分析显示脾—湿支持度和置信度最高,聚类分析结果可得到3个聚类组。结论 糖尿病前期病位在脾,气虚、脾、痰、湿是常见证素,临床诊治糖尿病前期应注重从脾论治,需辨证施治。  相似文献   
60.
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