全文获取类型
收费全文 | 45362篇 |
免费 | 3356篇 |
国内免费 | 135篇 |
专业分类
耳鼻咽喉 | 592篇 |
儿科学 | 1139篇 |
妇产科学 | 552篇 |
基础医学 | 5670篇 |
口腔科学 | 475篇 |
临床医学 | 4758篇 |
内科学 | 9144篇 |
皮肤病学 | 481篇 |
神经病学 | 4470篇 |
特种医学 | 1777篇 |
外科学 | 8727篇 |
综合类 | 349篇 |
现状与发展 | 1篇 |
一般理论 | 56篇 |
预防医学 | 3757篇 |
眼科学 | 801篇 |
药学 | 2845篇 |
中国医学 | 34篇 |
肿瘤学 | 3225篇 |
出版年
2024年 | 61篇 |
2023年 | 479篇 |
2022年 | 853篇 |
2021年 | 2060篇 |
2020年 | 1068篇 |
2019年 | 1711篇 |
2018年 | 2068篇 |
2017年 | 1450篇 |
2016年 | 1468篇 |
2015年 | 1621篇 |
2014年 | 2328篇 |
2013年 | 2752篇 |
2012年 | 4352篇 |
2011年 | 4243篇 |
2010年 | 2229篇 |
2009年 | 1880篇 |
2008年 | 2965篇 |
2007年 | 3070篇 |
2006年 | 2579篇 |
2005年 | 2300篇 |
2004年 | 2016篇 |
2003年 | 1692篇 |
2002年 | 1477篇 |
2001年 | 168篇 |
2000年 | 132篇 |
1999年 | 170篇 |
1998年 | 258篇 |
1997年 | 201篇 |
1996年 | 142篇 |
1995年 | 122篇 |
1994年 | 99篇 |
1993年 | 75篇 |
1992年 | 59篇 |
1991年 | 44篇 |
1990年 | 38篇 |
1989年 | 39篇 |
1988年 | 38篇 |
1987年 | 43篇 |
1986年 | 33篇 |
1985年 | 38篇 |
1984年 | 38篇 |
1983年 | 34篇 |
1982年 | 39篇 |
1981年 | 27篇 |
1980年 | 32篇 |
1979年 | 15篇 |
1978年 | 17篇 |
1974年 | 19篇 |
1973年 | 17篇 |
1972年 | 14篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
81.
Matthew P Smelley Daniel E Virnich Kim A Williams R Parker Ward 《Journal of nuclear cardiology》2007,14(4):537-543
BACKGROUND: A hypertensive response to exercise (HRE) is associated with false-positive stress echocardiograms and myocardial perfusion single photon emission computed tomography (myocardial perfusion imaging [MPI]) defects even in the absence of coronary artery disease (CAD). Transient ischemic dilation (TID) of the left ventricle on stress MPI is a marker of severe CAD and future cardiac events. This study evaluated the association between an HRE and TID. METHODS AND RESULTS: Blinded quantitative TID assessment was performed in 125 patients who had an HRE and a summed stress score (SSS) of less than 4, as well as 125 control patients with an SSS of less than 4 and without an HRE matched for age, gender, and resting systolic blood pressure. Cardiac comorbidities, pretest Framingham risk, and exercise results were recorded. TID was defined as a stress-to-rest volume ratio of 1.22 or greater. An HRE was associated with a high prevalence of TID and significantly more TID than no HRE (25.6% vs 11.2%; odds ratio, 3.00 [95% confidence interval, 1.41-6.38]). TID was more prevalent even in subgroups with a low pretest probability CAD, including those without diabetes mellitus or angina. On conditional logistic regression analysis, an HRE was found to be independently associated with TID after consideration of other clinical and exercise MPI variables (odds ratio, 2.72 [95% confidence interval, 1.01-7.31]). CONCLUSION: An HRE is associated with a high prevalence of TID in patients without other significant perfusion defects, possibly as a result of global subendocardial ischemia induced by the HRE. 相似文献
82.
83.
Danan Gu Matthew E. Dupre David F. Warner Yi Zeng 《Social science & medicine (1982)》2009,68(12):2170-2179
Numerous studies document improvements in health status and health expectancies among older adults over time. However, most evidence is from developed nations and gender differences in health trends are often inconsistent. It remains unknown whether changes in health in developing countries resemble Western trends or whether patterns of health improvement are unique to the country's epidemiologic transition and gender norms. Using two nationally representative samples of non-institutionalized adults in China aged 65 years and older, this study investigates gender differences in the improvements in disability, chronic disease prevalence, and self-rated health from 1992 to 2002. Results from multivariate logistic regression models show that all three indicators of health improved over the 10-year period, with the largest improvement in self-rated health. With the exception of disability, the health of women improved more than men. Using Sullivan's decomposition methods, we also show that active life expectancy, disease-free life expectancy, and healthy life expectancy increased over this decade and were patterned differently according to gender. Overall, the findings demonstrate that China experienced broad health improvements during its early stages of the epidemiologic transition and that these changes were not uniform by gender. We discuss the public health implications of the findings in the context of China's rapidly aging population. 相似文献
84.
85.
86.
87.
88.
A review of in-situ EBSD experiments 总被引:4,自引:1,他引:3
IntroductionIn the firstautomated Electron Backscatter Diffrac-tion(EBSD)[1]or Orientation Imaging Microscopy(OIM)[2]systems,patterns were indexed at a rate ofabout four seconds per pattern.In the past decade,OIMscan speeds have increased to over 300 times fas-ter than the original measurements.During this sametime period,scanning electron microscope(SEM)technology has also seen large improvements enablingthe OIMtechnique to be applied at higher spatial reso-lutions and with more flex… 相似文献
89.
Combined Endoscopic Thermal Electrocoagulation with High Dose Omeprazole Therapy in Complicated Heterotopic Gastric Mucosa of the Esophagus 总被引:3,自引:0,他引:3
90.
Anita E. Kelly Matthew E. Coenen Benjamin L. Johnston 《Journal of traumatic stress》1995,8(1):161-169
One hundred six undergraduate (83 women and 23 men) completed surveys concerning their most traumatic life event, the feedback they received following their disclosure of the event to others, and how they felt after the disclosure. Results indicated that the better they felt after disclosure, the less disturbed they were by thoughts of the event at the time of the study. In addition, the more personal the trauma was, the worse they felt after their disclosure, and the more disturbed they were about the trauma. However, no significant relation existed between the positivity (e.g., supportiveness) of their confidant's feedback and their present degree of disturbance. Implications for understanding the complex relation between confiding traumatic events and resolving feelings surrounding those events were discussed. 相似文献