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   3148872篇
  免费   271635篇
  国内免费   13738篇
耳鼻咽喉   43667篇
儿科学   99821篇
妇产科学   81391篇
基础医学   507257篇
口腔科学   84177篇
临床医学   278267篇
内科学   555886篇
皮肤病学   85712篇
神经病学   272320篇
特种医学   125301篇
外国民族医学   361篇
外科学   496702篇
综合类   96702篇
现状与发展   23篇
一般理论   2167篇
预防医学   263742篇
眼科学   71110篇
药学   214210篇
  22篇
中国医学   9194篇
肿瘤学   146213篇
  2021年   54565篇
  2020年   34833篇
  2019年   57776篇
  2018年   70179篇
  2017年   53525篇
  2016年   59050篇
  2015年   73397篇
  2014年   107384篇
  2013年   172416篇
  2012年   83914篇
  2011年   82905篇
  2010年   114136篇
  2009年   119436篇
  2008年   70806篇
  2007年   72806篇
  2006年   83881篇
  2005年   79885篇
  2004年   81829篇
  2003年   73231篇
  2002年   63320篇
  2001年   89194篇
  2000年   81782篇
  1999年   84930篇
  1998年   63413篇
  1997年   61769篇
  1996年   59479篇
  1995年   54925篇
  1994年   49122篇
  1993年   45914篇
  1992年   58536篇
  1991年   55220篇
  1990年   52396篇
  1989年   51790篇
  1988年   48336篇
  1987年   47249篇
  1986年   45298篇
  1985年   45489篇
  1984年   43087篇
  1983年   39914篇
  1982年   39838篇
  1981年   37588篇
  1980年   35551篇
  1979年   35087篇
  1978年   32153篇
  1977年   29699篇
  1976年   27278篇
  1975年   25790篇
  1974年   26281篇
  1973年   25128篇
  1972年   23657篇
排序方式: 共有10000条查询结果,搜索用时 668 毫秒
961.
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   
962.
963.
964.
965.
966.
967.
968.
969.
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   
970.

Objective

To discover the experiences of end-of-life patients attended by the emergency services, through the discourse of the family caregivers who accompanied the family member in this care transit.

Method

A qualitative approach study, based on the paradigm of hermeneutical phenomenology. In total, 81 family caregivers participated. The techniques used were the in-depth interview and the discussion group, with a total of 5 discussion groups and 41 interviews. The period of data collection was carried out between January 2013 and June 2014.

Results

In the network of discourses obtained with respect to “Urgent Care”, all the codes were grouped in relation to a single argumentative line: deficiencies in urgent care. Among them, we found different dimensions that are established depending on the different times of care, or the different determinant aspects of these deficiencies: disorganization of the care received, lack of experience of the professionals in emergencies, application of general protocols in the emergency services, inadequate care in the treatment received, delays in emergency care.

Conclusions

In general, we highlight the dissatisfaction of the family members with respect to the care received from the emergency services. The needs of these types of situation are not covered from these services and are of low quality. Therefore, it is necessary to reorient the care protocols for these 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