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   44299篇
  免费   2686篇
  国内免费   320篇
耳鼻咽喉   283篇
儿科学   1481篇
妇产科学   758篇
基础医学   3632篇
口腔科学   652篇
临床医学   2944篇
内科学   6610篇
皮肤病学   680篇
神经病学   1569篇
特种医学   1394篇
外科学   5406篇
综合类   9922篇
一般理论   11篇
预防医学   7900篇
眼科学   440篇
药学   1867篇
  50篇
中国医学   866篇
肿瘤学   840篇
  2024年   97篇
  2023年   816篇
  2022年   1341篇
  2021年   1903篇
  2020年   1482篇
  2019年   3356篇
  2018年   2844篇
  2017年   1648篇
  2016年   816篇
  2015年   859篇
  2014年   2411篇
  2013年   2126篇
  2012年   2310篇
  2011年   2373篇
  2010年   1971篇
  2009年   1684篇
  2008年   1542篇
  2007年   1346篇
  2006年   1278篇
  2005年   857篇
  2004年   646篇
  2003年   528篇
  2002年   381篇
  2001年   336篇
  2000年   290篇
  1999年   254篇
  1998年   200篇
  1997年   204篇
  1996年   153篇
  1995年   157篇
  1994年   140篇
  1993年   75篇
  1992年   40篇
  1991年   50篇
  1990年   45篇
  1988年   32篇
  1987年   29篇
  1985年   867篇
  1984年   1398篇
  1983年   1114篇
  1982年   1103篇
  1981年   1104篇
  1980年   963篇
  1979年   847篇
  1978年   664篇
  1977年   468篇
  1976年   634篇
  1975年   552篇
  1974年   469篇
  1973年   434篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
FDA’S Perspectives on Cardiovascular Devices   总被引:1,自引:0,他引:1  
The Food and Drug Administration (FDA) decision process for approving or clearing medical devices is often determined by a review of robust clinical data and extensive preclinical testing of the device. The mission statement for the Center for Devices and Radiological Health (CDRH) is to review the information provided by manufacturers so that it can promote and protect the health of the public by ensuring the safety and effectiveness of medical devices deemed appropriate for human use (Food, Drug & Cosmetic Act, §903(b)(1, 2(C)), December 31, 2004; accessed December 17, 2008 ). For high-risk devices, such as ventricular assist devices (VADs), mechanical heart valves, stents, cardiac resynchronization therapy (CRT) devices, pacemakers, and defibrillators, the determination is based on FDA’s review of extensive preclinical bench and animal testing followed by use of the device in a clinical trial in humans. These clinical trials allow the manufacturer to evaluate a device in the intended use population. FDA reviews the data from the clinical trial to determine if the device performed as predicted and the clinical benefits outweigh the risks. This article reviews the regulatory framework for different marketing applications related to cardiovascular devices and describes the process of obtaining approval to study a cardiovascular device in a U.S. clinical trial.  相似文献   
82.
83.
Few cases in the history of epidemiology and public health are more famous than John Snow's investigation of a neighborhood cholera outbreak in the St. James, Westminster, area of London in 1854. In this study Snow is assumed to have proven that cholera was water rather than airborne through a methodology that became, and to a great extent remains, central to the science and social science of disease studies. And yet, Snow's work did not satisfy most of his contemporaries who considered his proof of a solely waterborne cholera interesting but unconvincing. Uniquely, this paper asks whether the caution of Snow's contemporaries was reasonable, and secondly, whether Snow might have been more convincing within the science of the day. The answers significantly alter our understanding of this paradigmatic case. It does so in a manner offering insights both into the origins of nineteenth century disease analysis and more generally, the relation of mapping in the investigation of an outbreak of uncertain origin. The result has general relevance—pedagogically and practically—in epidemiology, medical geography, and public health.  相似文献   
84.
针对当前的医学文献检索课中忽略期刊论文分类标引教学的问题,总结了几点教学实践,分别从期刊论文分类标引准确的重要性、期刊论文分类标引的步骤及原则、医学期刊论文分类标引的注意事项几个方面进行阐述.  相似文献   
85.
Neural plasticity of modality-nonspecific and modality-specific memory and learning abilities pertains to fluid intelligence and crystallized intelligence, respectively. The limbic system with the novelty neurons of the hippocampus interacts with the prefrontal cortex optimization of the orienting reflex and voluntary attention. Brain-derived neurotrophic factor produced by novelty neurons of the hippocampus contributes to long-term memory formation and improves learning abilities in a wide range of disciplines. Synergistic combination of stimulation with “analytical-specific visual perceptual patterns” and “optimally high” physiological activation of the bilateral electrodermal system optimizes the limbic system and prefrontal cortex activity as demonstrated by enhanced prefrontal N450 ERPs to a memory workload paradigm. This is accompanied by improvements in auditory retention tasks, word memorization, higher school achievement and marks, and an amelioration of “analytical-specific perceptual skills” as measured by the Mangina-Test. Intracerebral ERPs to a memory workload paradigm contributed to the elucidation of limbic structures and neocortical sites involved in memory workload processes. The progressive degeneration of these same structures causes the gradual decline of memory functions observed in early Alzheimer's disease. Research findings indicate that ERPs elicited by a memory workload paradigm are sensitive markers for diagnosis, treatment and clinical follow-up of early Alzheimer's patients. In addition, ERPs provide objective measurement of cholinergic medication effects on cerebral functions involved in memory processes through neuropsychophysiological parameters.  相似文献   
86.
87.
引入PDCA循环规范医疗废物管理   总被引:2,自引:0,他引:2  
目的采用PDCA循环法,规范医院医疗废物管理。方法通过计划、实施、检查、处理4个阶段具体实施。结果医疗废物要达到规范化管理,建立有效的组织管理体系,制定切实可行的规章制度是重要保证;加强培训与宣传教育,提高全员管理意识是重要环节;完善医疗废物处置过程中的配套设施是重要基础;制定管理质量标准认真督促检查考核是重要手段。结论PDCA循环法是加强完善医疗废物管理的一种科学的管理方式。  相似文献   
88.
探索临床技能培训和提高学生临床实践能力的有效方法.通过培训前考核、观看教学片、指导教师示范、模拟练习、现场点评、培训后考核等方式,比较培训前后考核成绩.通过短期集中培训,使实习生在临床技能方面快速提高.学生们很快掌握了临床基本技能操作规范,为更好地投入到临床实习打下了良好的基础.  相似文献   
89.
清代名医的医德(二)   总被引:1,自引:1,他引:0  
用生动事例介绍清代名医的医德,以供后人效法和学习。  相似文献   
90.
The choice of therapies for Crohn's disease has expanded greatly over the past 30 years. Increasingly it is important that we attempt to identify subgroups of patients who will benefit most from each type of therapy. This article reviews the therapeutic options currently available, organized by the goal the practitioner hopes to achieve. Imaging is one critical way of aiding the classification of Crohn's disease by attempting to accurately determine the location, extent and, most importantly, the nature of the disease.  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