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   3316篇
  免费   469篇
  国内免费   91篇
耳鼻咽喉   50篇
儿科学   37篇
妇产科学   27篇
基础医学   494篇
口腔科学   44篇
临床医学   220篇
内科学   388篇
皮肤病学   29篇
神经病学   122篇
特种医学   105篇
外国民族医学   1篇
外科学   312篇
综合类   572篇
预防医学   537篇
眼科学   33篇
药学   430篇
  5篇
中国医学   201篇
肿瘤学   269篇
  2024年   30篇
  2023年   129篇
  2022年   215篇
  2021年   255篇
  2020年   261篇
  2019年   213篇
  2018年   173篇
  2017年   154篇
  2016年   118篇
  2015年   120篇
  2014年   217篇
  2013年   238篇
  2012年   189篇
  2011年   221篇
  2010年   174篇
  2009年   141篇
  2008年   188篇
  2007年   147篇
  2006年   116篇
  2005年   107篇
  2004年   98篇
  2003年   76篇
  2002年   51篇
  2001年   40篇
  2000年   37篇
  1999年   32篇
  1998年   23篇
  1997年   17篇
  1996年   14篇
  1995年   15篇
  1994年   15篇
  1993年   11篇
  1992年   9篇
  1991年   8篇
  1990年   6篇
  1989年   5篇
  1988年   2篇
  1986年   2篇
  1985年   1篇
  1984年   2篇
  1983年   1篇
  1981年   2篇
  1980年   2篇
  1979年   1篇
排序方式: 共有3876条查询结果,搜索用时 15 毫秒
1.
目的 基于文本挖掘技术和生物医学数据库对新型冠状病毒肺炎(COVID-19)相关文献进行数据挖掘分析,探究COVID-19及其主要症状发热、咳嗽、呼吸障碍相关基因靶点,筛选潜在有效的化学药和中药。方法 使用GenCLiP 3网站获取COVID-19和其主要症状咳嗽、发热、呼吸障碍共4个关键词的共有靶点,在METASCAPE数据库中对其进行基因本体(GO)和通路富集分析,再利用String数据库和Cytoscape软件构建共有靶点的蛋白质相互作用网络,筛选获得核心基因,运用DGIdb数据库、SymMap数据库针对核心基因进行中西医治疗药物预测。结果 获得COVID-19及其主要症状共有基因靶点28个,其中有IL2、IL1B、CCL2等核心基因16个,使用DGIdb数据库筛选获得与16个关键靶点相互作用的化学药包括沙利度胺、来氟米特、环孢素等28种,中药包括虎杖、黄芪、芦荟等70味。结论 COVID-19及其主要症状的病理机制可能和CD4、KNG1、VEGFA等28个共有基因相关,可能通过介导TNF、IL-17等信号通路参与COVID-19病理过程。潜在有效药物可能通过作用相关靶点通路起到治疗COVID-19的作用。  相似文献   
2.
3.
Precise data on food chemical composition is crucial for any quantitative nutrition research and indispensable for evaluation and planning of computer-based menus. Moreover, exact food chemical composition is of the utmost importance in composing specific diets that may be low in certain essential nutrients. Therefore, this research evaluated a weekly vegan menu using three different food composition databases (FCDB): the Croatian, the official Danish Food Composition Database and the United States Department of Agriculture (USDA) – National Nutrient Database for Standard Reference. Significant differences (p < 0.05) were determined in evaluated and optimised offers for the same menu when using different FCDBs. Furthermore, in these menus quantities of some nutrients have not reached official daily recommendations needed for prevention of non-communicable diseases. In this research, new vegan menus that can provide adequate quantity of essential nutrients, regardless of FCDB utilized, were created with linear optimisation (LO). This resulted in high quality daily menu offers. However, depending on the FCDB that was used, optimal menus differed in daily meal combinations, and the effectiveness of the optimisation in the minimisation of differences caused by differences of data in FCDBs was tested. Linear optimisation has been proved to be an effective tool in planning of specific diets, such as vegan diets. Nonetheless, the quality of computer-planned menus depends heavily on the quality of FCDB used.  相似文献   
4.
5.
Modern artificial intelligence techniques have solved some previously intractable problems and produced impressive results in selected medical domains. One of their drawbacks is that they often need very large amounts of data. Pre-existing datasets in the form of national cancer registries, image/genetic depositories and clinical datasets already exist and have been used for research. In theory, the combination of healthcare Big Data with modern, data-hungry artificial intelligence techniques should offer significant opportunities for artificial intelligence development, but this has not yet happened. Here we discuss some of the structural reasons for this, barriers preventing artificial intelligence from making full use of existing datasets, and make suggestions as to enable progress. To do this, we use the framework of the 6Vs of Big Data and the FAIR criteria for data sharing and availability (Findability, Accessibility, Interoperability, and Reuse). We share our experience in navigating these barriers through The Brain Tumour Data Accelerator, a Brain Tumour Charity-supported initiative to integrate fragmented patient data into an enriched dataset. We conclude with some comments as to the limits of such approaches.  相似文献   
6.
7.

Background

The ZOE-50 (NCT01165177) and ZOE-70 (NCT01165229) phase 3 clinical trials showed that the adjuvanted recombinant zoster vaccine (RZV) was ≥90% efficacious in preventing herpes zoster in adults. Here we present a comprehensive overview of the safety data from these studies.

Methods

Adults aged ≥50 (ZOE-50) and ≥70 (ZOE-70) years were randomly vaccinated with RZV or placebo. Safety analyses were performed on the pooled total vaccinated cohort, consisting of participants receiving at least one dose of RZV or placebo. Solicited and unsolicited adverse events (AEs) were collected for 7 and 30?days after each vaccination, respectively. Serious AEs (SAEs) were collected from the first vaccination until 12?months post-last dose. Fatal AEs, vaccination-related SAEs, and potential immune-mediated diseases (pIMDs) were collected during the entire study period.

Results

Safety was evaluated in 14,645 RZV and 14,660 placebo recipients. More RZV than placebo recipients reported unsolicited AEs (50.5% versus 32.0%); the difference was driven by transient injection site and solicited systemic reactions that were generally seen in the first week post-vaccination. The occurrence of overall SAEs (RZV: 10.1%; Placebo: 10.4%), fatal AEs (RZV: 4.3%; Placebo: 4.6%), and pIMDs (RZV: 1.2%; Placebo: 1.4%) was balanced between groups. The occurrence of possible exacerbations of pIMDs was rare and similar between groups. Overall, except for the expected local and systemic symptoms, the safety results were comparable between the RZV and Placebo groups irrespective of participant age, gender, or race.

Conclusions

No safety concerns arose, supporting the favorable benefit-risk profile of RZV.  相似文献   
8.
目的 分析tCGA数据库中肝内胆管癌(ICC)高通量测序数据,寻找其预后相关基因,构建风险模型,并研究其在ICC组织中表达及作用通路。方法 下载tCGA数据库中33例ICC组织和8例癌旁组织中的RNA-seq表达矩阵数据和患者临床资料信息,利用edgeR软件包进行基因差异表达分析,通过单因素Cox回归分析筛选出预后相关差异基因,对差异基因绘制生存曲线,筛选出具有临床意义的基因,经多因素Cox回归分析并构建风险模型,通过京都基因与基因组百科全书(KEGG)通路富集分析了解预后相关基因的作用通路。结果 通过edgeR分析后得到6 617个差异基因(筛选标准为|log2 Fold Change|>1,P<0.05),其中高表达组4 094个,低表达组2 523个。通过功能富集发现,这些基因主要集中在化学物致癌作用、药物代谢-细胞色素P450系统、细胞色素P450对异生物质的代谢影响以及视黄醇代谢通路。经单因素Cox回归、R软件“survival”包生存曲线分析显示,UCN2、CST1、PROS1、SLC35E4、PEMT五个基因对ICC患者预后存在显著性影响。通过多因素Cox回归分析,CST1、PEMT、PROS1构建的风险模型对ICC患者预后具有判断作用。结论 UCN2、CST1、PROS1、SLC35E4、PEMT基因可能成为ICC预后判断指标,为后续临床试验提供数据支持。  相似文献   
9.
10.
科室调整时。病人要随之分配到新的科室,病人的各种医疗数据要转换为新科室的数据。利用结构化查询语言,根据病人的调整情况,实施数据调整。这种数据转换方法,不但适用于新、老药品结构的“军卫一号”,而且其基本原理也适用于科室分开而护理单元不分开的情况。  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