全文获取类型
收费全文 | 44421篇 |
免费 | 3043篇 |
国内免费 | 170篇 |
专业分类
耳鼻咽喉 | 282篇 |
儿科学 | 1504篇 |
妇产科学 | 1000篇 |
基础医学 | 5188篇 |
口腔科学 | 884篇 |
临床医学 | 4587篇 |
内科学 | 9415篇 |
皮肤病学 | 779篇 |
神经病学 | 4215篇 |
特种医学 | 1395篇 |
外科学 | 6848篇 |
综合类 | 914篇 |
一般理论 | 65篇 |
预防医学 | 3609篇 |
眼科学 | 1152篇 |
药学 | 3081篇 |
中国医学 | 50篇 |
肿瘤学 | 2666篇 |
出版年
2023年 | 183篇 |
2022年 | 355篇 |
2021年 | 768篇 |
2020年 | 485篇 |
2019年 | 766篇 |
2018年 | 890篇 |
2017年 | 708篇 |
2016年 | 726篇 |
2015年 | 897篇 |
2014年 | 1259篇 |
2013年 | 1876篇 |
2012年 | 2915篇 |
2011年 | 3093篇 |
2010年 | 1755篇 |
2009年 | 1610篇 |
2008年 | 2800篇 |
2007年 | 3036篇 |
2006年 | 2978篇 |
2005年 | 3057篇 |
2004年 | 2870篇 |
2003年 | 2660篇 |
2002年 | 2647篇 |
2001年 | 505篇 |
2000年 | 375篇 |
1999年 | 506篇 |
1998年 | 672篇 |
1997年 | 492篇 |
1996年 | 436篇 |
1995年 | 392篇 |
1994年 | 327篇 |
1993年 | 328篇 |
1992年 | 298篇 |
1991年 | 267篇 |
1990年 | 265篇 |
1989年 | 253篇 |
1988年 | 221篇 |
1987年 | 196篇 |
1986年 | 223篇 |
1985年 | 217篇 |
1984年 | 307篇 |
1983年 | 261篇 |
1982年 | 340篇 |
1981年 | 300篇 |
1980年 | 297篇 |
1979年 | 174篇 |
1978年 | 167篇 |
1977年 | 170篇 |
1976年 | 145篇 |
1975年 | 123篇 |
1974年 | 134篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Hanna Lee Mary K. Tan Andrew T. Yan Paul Angaran Paul Dorian Claudia Bucci Jean C. Gregoire Alan D. Bell Martin S. Green Peter L. Gross Allan Skanes Charles R. Kerr L. Brent Mitchell Jafna L. Cox Vidal Essebag Brett Heilbron Krishnan Ramanathan Carl Fournier Shaun G. Goodman 《The Canadian journal of cardiology》2019,35(2):160-168
Background
Physicians treating nonvalvular atrial fibrillation (AF) assess stroke and bleeding risks when deciding on anticoagulation. The agreement between empirical and physician-estimated risks is unclear. Furthermore, the association between patient and physician sex and anticoagulation decision-making is uncertain.Methods
We pooled data from 2 national primary care physician chart audit databases of patients with AF (Facilitating Review and Education to Optimize Stroke Prevention in Atrial Fibrillation and Coordinated National Network to Engage Physicians in the Care and Treatment of Patients with Atrial Fibrillation Chart Audit) with a combined 1035 physicians (133 female, 902 male) and 10,927 patients (4567 female and 6360 male).Results
Male physicians underestimated stroke risk in female patients and overestimated risk in male patients. Female physicians estimated stroke risk well in female patients but underestimated the risk in male patients. Risk of bleeding was underestimated in all. Despite differences in risk assessment by physician and patient sex, > 90% of patients received anticoagulation across all subgroups. There was modest agreement between physician estimated and calculated (ie, CHADS2 score) stroke risk: Kappa scores were 0.41 (0.35-0.47) for female physicians and 0.34 (0.32-0.36) for male physicians.Conclusions
Our study is the first to examine the association between patient and physician sex influences and stroke and bleeding risk estimation in AF. Although there were differences in agreement between physician estimated stroke risk and calculated CHADS2 scores, these differences were small and unlikely to affect clinical practice; further, despite any perceived differences in the accuracy of risk assessment by sex, most patients received anticoagulation. 相似文献3.
4.
Juin Fok-Seang Linda C. Smith-Thomas Sally Meiners Elizabeth Muir Jian-Sheng Du Elizabeth Housden Alan R. Johnson Andreas Faissner Herbert M. Geller Roger J. Keynes John H. Rogers James W. Fawcett 《Brain research》1995,689(2):207
The adult mammalian central nervous system (CNS) lacks the capacity to support axonal regeneration. There is increasing evidence to suggest that astrocytes, the major glial population in the CNS, may possess both axon-growth promoting and axon-growth inhibitory properties and the latter may contribute to the poor regenerative capacity of the CNS. In order to examine the molecular differences between axon-growth permissive and axon-growth inhibitory astrocytes, a panel of astrocyte cell lines exhibiting a range of axon-growth promoting properties was generated and analysed. No clear correlation was found between the axon-growth promoting properties of these astrocyte cell lines with: (i) the expression of known neurite-outgrowth promoting molecules such as laminin, fibronectin andN-cadherin; (ii) the expression of known inhibitory molecules such tenascin and chondroitin sulphate proteoglycan; (iii) plasminogen activator and plasminogen activator inhibitor activity; and (iv) growth cone collapsing activity. EM studies on aggregates formed from astrocyte cell lines, however, revealed the presence of an abundance of extracellular matrix material associated with the more inhibitory astrocyte cell lines. When matrix deposited by astrocyte cell lines was assessed for axon-growth promoting activity, matrix from permissive lines was found to be a good substrate, whereas matrix from the inhibitory astrocyte lines was a poor substrate for neuritic growth. Our findings, taken together, suggest that the functional differences between the permissive and the inhibitory astrocyte cell lines reside largely with the ECM. 相似文献
5.
6.
A new range of stand magnifiers has been released by the COIL company in the United Kingdom. Examination of these magnifiers reveals that they fail to deliver the rated magnifications labelled prominently on the appliances, as a result of the manufacturer's conformance with the requirements of the German DIN standard and the use of back vertex power (F'v) rather than equivalent dioptric power (Fm) of the magnifier. In this study we provide information on the optometric parameters of these new stand magnifiers that will assist the more accurate specification of improvements in vision expected from their use. 相似文献
7.
8.
Single-cause Attribution 总被引:3,自引:1,他引:2
Alan Leviton 《Developmental medicine and child neurology》1987,29(6):805-807
9.
Stanford''s two decades of success in linking medical informatics and health services research in both training and investigational activities reflects advantageous geography and history as well as natural synergies in the two areas. Health services research and medical informatics at Stanford have long shared a quantitative, analytic orientation, along with linked administration, curriculum, and clinical activities. Both the medical informatics and the health services research curricula draw on diverse course offerings throughout the university, and both the training and research overlap in such areas as outcomes research, large database analysis, and decision analysis/decision support. The Stanford experience suggests that successful integration of programs in medical informatics and health services research requires areas of overlapping or synergistic interest and activity among the involved faculty and, hence, in time, among the students. This is enhanced by a mixture of casual and structured contact among students from both disciplines, including social interactions. The challenges to integration are how to overcome any geographic separation that may exist in a given institution; the proper management of relationships with those sub-areas of medical informatics that have less overlap with health services research; and the need to determine how best to exploit opportunities for collaboration that naturally occur.Training in medical informatics and health services research has been closely linked at Stanford University for almost two decades. Although the close linkage was deliberate, it was facilitated by historical circumstances, in particular the common academic structures in which both programs arose. In this paper, we describe some of that rationale and history, identifying the areas of overlap that we have pursued in coordinating the training opportunities for graduate students and fellows in both areas of study. As we shall note, the synergies have been great, and in some cases trainees have collaborated closely on research while also taking some of the same courses. We believe that these interactions can be a model for the design of training programs that encourage scholarly interactions between medical informatics and health services research. Although our initial charge was to describe both the successes and failures in integrating the programs, we found that we could not identify any outright failures and that it would be better to delineate the complexities and challenges that we have faced in bringing together these two disciplines. 相似文献
10.