全文获取类型
收费全文 | 161435篇 |
免费 | 31731篇 |
国内免费 | 2490篇 |
专业分类
耳鼻咽喉 | 5282篇 |
儿科学 | 5510篇 |
妇产科学 | 2553篇 |
基础医学 | 4230篇 |
口腔科学 | 1703篇 |
临床医学 | 27153篇 |
内科学 | 50443篇 |
皮肤病学 | 7624篇 |
神经病学 | 15579篇 |
特种医学 | 6771篇 |
外科学 | 42674篇 |
综合类 | 306篇 |
现状与发展 | 72篇 |
一般理论 | 1篇 |
预防医学 | 7291篇 |
眼科学 | 3610篇 |
药学 | 1679篇 |
中国医学 | 23篇 |
肿瘤学 | 13152篇 |
出版年
2024年 | 699篇 |
2023年 | 4853篇 |
2022年 | 1329篇 |
2021年 | 3353篇 |
2020年 | 6156篇 |
2019年 | 2331篇 |
2018年 | 7598篇 |
2017年 | 7515篇 |
2016年 | 8635篇 |
2015年 | 8660篇 |
2014年 | 15776篇 |
2013年 | 15967篇 |
2012年 | 6082篇 |
2011年 | 6101篇 |
2010年 | 10683篇 |
2009年 | 14574篇 |
2008年 | 6402篇 |
2007年 | 4685篇 |
2006年 | 7132篇 |
2005年 | 4407篇 |
2004年 | 3673篇 |
2003年 | 2610篇 |
2002年 | 2699篇 |
2001年 | 4012篇 |
2000年 | 3196篇 |
1999年 | 3413篇 |
1998年 | 3795篇 |
1997年 | 3567篇 |
1996年 | 3458篇 |
1995年 | 3305篇 |
1994年 | 2021篇 |
1993年 | 1622篇 |
1992年 | 1500篇 |
1991年 | 1518篇 |
1990年 | 1166篇 |
1989年 | 1274篇 |
1988年 | 1125篇 |
1987年 | 950篇 |
1986年 | 978篇 |
1985年 | 788篇 |
1984年 | 611篇 |
1983年 | 569篇 |
1982年 | 551篇 |
1981年 | 422篇 |
1980年 | 376篇 |
1979年 | 343篇 |
1978年 | 346篇 |
1977年 | 422篇 |
1975年 | 304篇 |
1972年 | 320篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
62.
63.
64.
65.
66.
Paul Wexberg MD BM Richard Pacher MD Suzanne Rdler MD Katharina Kiss MD Gilbert Beran MD Michael Grimm MD Gerald Maurer MD Dietmar Glogar MD FESC 《The Journal of heart and lung transplantation》2002,21(12):583-1263
BACKGROUND: Endothelin, a peptide with strong vasoconstrictive and mitogenic properties, has been found to increase after cardiac transplantation. We therefore assessed the association between its precursor peptide, big endothelin-1, and intimal hyperplasia and coronary flow reserve after heart transplantation. METHODS: Thirty-five patients without hemodynamically significant coronary artery disease after heart transplantation were investigated: Average peak flow velocity in the left anterior descending artery (LAD) was assessed by intracoronary Doppler at baseline as well as after injection of adenosine; coronary flow reserve was calculated as a ratio of both and was corrected for patient age and baseline average peak flow velocity. Lumen, intima + media and total vessel area were measured by intracoronary ultrasound. The plasma concentration of big endothelin-1 in venous blood was determined by radioimmunoassay. RESULTS: Patients with elevated big endothelin-1 levels (>2 fmol/ml) tended to have a decreased corrected coronary flow reserve (2.60 +/- 0.9 vs 3.21 +/- 1.0, p = 0.078). They also had a significantly larger intima + media area (5.82 +/- 2.9 vs 2.37 +/- 2.9 mm(2), p = 0.004) and total vessel area (18.36 +/- 5.8 vs 12.81 +/- 4.8 mm(2), p = 0.012) than those with normal plasma concentrations. CONCLUSIONS: Our study suggests an association between elevated big endothelin-1 plasma levels and the development of intimal hyperplasia and reduction of coronary flow reserve after cardiac transplantation. 相似文献
67.
68.
T Iino N Toyosaki T Katsuki T Noda T Natsume T Yaginuma S Hosoda M Furuse 《Clinical nuclear medicine》1987,12(9):688-693
The perfusion territories in polar representations of stress Tl-201 rotational myocardial imaging in patients with angina pectoris who had one diseased coronary segment were analyzed. The lesions proximal or distal to the first major septal perforator in left anterior descending arteries were detected by the presence or absence of defects at the base of the anterior septum. Right coronary artery lesions were detected by the presence of defects at the basal posterior septum, in contrast to the preservation of myocardial uptake at this portion in lesions of the left circumflex artery. The specific defect patterns were detected in cases with lesions at the first diagonal, obtuse marginal, and posterolateral branches. Recognition of these defects in the polar maps allows detailed detection of diseased coronary arterial branches. 相似文献
69.
70.
Jeffrey H. Coben MD 《Academic emergency medicine》2002,9(11):1176-1183
OBJECTIVE: To obtain consensus among a panel of experts on performance measures useful for evaluating the quality of hospital-based domestic violence (DV) programs. METHODS: The Delphi process of consensus development was used with a panel of 18 experts including DV researchers, program planners, and advocates. Three rounds were conducted over a period of six months, with each round involving the completion of a written questionnaire. Panelists were instructed to concentrate on structure and process measures of DV program performance. Health outcome measures were not considered. During each round, panelists rated (scale of 1-5) their level of agreement with each measure, in terms of the measure's usefulness for evaluating hospital-based DV programs. Data were entered into SPSS on a personal computer and frequency distributions, measures of central tendency, and variance were computed for each measure. Consensus development was defined as a reduction in the item-specific variance from one round to the next. RESULTS: A total of 37 performance measures were agreed upon. These measures fell within nine different domains of DV program activities, including: Policies and Procedures, Hospital Physical Environment, Hospital Cultural Environment, Training of Providers, Screening and Safety Assessment, Documentation, Intervention Services, Evaluation Activities, and Collaboration. CONCLUSIONS: A number of measures have been identified as useful for evaluating hospital-based DV programs. Use of these measures should assist researchers, program planners, and administrators in assessing the quality of hospital-based DV programs. 相似文献