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   3233826篇
  免费   280235篇
  国内免费   13704篇
耳鼻咽喉   44294篇
儿科学   104002篇
妇产科学   83017篇
基础医学   522348篇
口腔科学   86997篇
临床医学   292588篇
内科学   565140篇
皮肤病学   88388篇
神经病学   279484篇
特种医学   127423篇
外国民族医学   329篇
外科学   501556篇
综合类   100700篇
现状与发展   23篇
一般理论   2271篇
预防医学   275141篇
眼科学   73923篇
药学   220755篇
  23篇
中国医学   9314篇
肿瘤学   150049篇
  2021年   54851篇
  2020年   35023篇
  2019年   57992篇
  2018年   70806篇
  2017年   54040篇
  2016年   59631篇
  2015年   73763篇
  2014年   107928篇
  2013年   173216篇
  2012年   87179篇
  2011年   86698篇
  2010年   115405篇
  2009年   120111篇
  2008年   73762篇
  2007年   75932篇
  2006年   87087篇
  2005年   82354篇
  2004年   84694篇
  2003年   75714篇
  2002年   65409篇
  2001年   94414篇
  2000年   86951篇
  1999年   88666篇
  1998年   64321篇
  1997年   62366篇
  1996年   60136篇
  1995年   55676篇
  1994年   49943篇
  1993年   46514篇
  1992年   62342篇
  1991年   59455篇
  1990年   56557篇
  1989年   55936篇
  1988年   51595篇
  1987年   51011篇
  1986年   48122篇
  1985年   48640篇
  1984年   45274篇
  1983年   41552篇
  1982年   40685篇
  1981年   38493篇
  1980年   36199篇
  1979年   37054篇
  1978年   33747篇
  1977年   30956篇
  1976年   28454篇
  1975年   26802篇
  1974年   27574篇
  1973年   26526篇
  1972年   24641篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
961.
962.
Background  Machine learning (ML) has captured the attention of many clinicians who may not have formal training in this area but are otherwise increasingly exposed to ML literature that may be relevant to their clinical specialties. ML papers that follow an outcomes-based research format can be assessed using clinical research appraisal frameworks such as PICO (Population, Intervention, Comparison, Outcome). However, the PICO frameworks strain when applied to ML papers that create new ML models, which are akin to diagnostic tests. There is a need for a new framework to help assess such papers. Objective  We propose a new framework to help clinicians systematically read and evaluate medical ML papers whose aim is to create a new ML model: ML-PICO (Machine Learning, Population, Identification, Crosscheck, Outcomes). We describe how the ML-PICO framework can be applied toward appraising literature describing ML models for health care. Conclusion  The relevance of ML to practitioners of clinical medicine is steadily increasing with a growing body of literature. Therefore, it is increasingly important for clinicians to be familiar with how to assess and best utilize these tools. In this paper we have described a practical framework on how to read ML papers that create a new ML model (or diagnostic test): ML-PICO. We hope that this can be used by clinicians to better evaluate the quality and utility of ML papers.  相似文献   
963.
964.
965.
966.
967.
968.
969.
970.
Inbred mouse strains are the most widely used mammalian model organism in biomedical research owing to ease of genetic manipulation and short lifespan; however, each inbred strain possesses a unique repertoire of deleterious homozygous alleles that can make a specific strain more susceptible to a particular disease. In the current study, we report dystrophic cardiac calcinosis (DCC) in C.B‐17 SCID male mice at 10 weeks of age with no significant change in cardiac function. Acquisition of DCC was characterized by myocardial injury, fibrosis, calcification, and necrosis of the tissue. At 10 weeks of age, 38% of the C.B‐17 SCID mice from two different commercial colonies exhibited significant calcinosis on the ventricular epicardium, predominantly on the right ventricle. The frequency of calcinosis was more than 50% for mice obtained from Taconic's Cambridge City colony and 25% for mice obtained from Taconic's German Town colony. Interestingly, the DCC phenotype did not affect cardiac function at 10 weeks of age. No differences in echocardiography or electrocardiography were observed between the calcinotic and non‐calcinotic mice from either colony. Our findings suggest that C.B‐17 SCID mice exhibit DCC as early as 10 weeks of age with no significant impact on cardiac function. This strain of mice should be cautiously considered for the study of cardiac physiology.  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