全文获取类型
收费全文 | 2345篇 |
免费 | 187篇 |
国内免费 | 29篇 |
专业分类
耳鼻咽喉 | 22篇 |
儿科学 | 86篇 |
妇产科学 | 36篇 |
基础医学 | 250篇 |
口腔科学 | 47篇 |
临床医学 | 277篇 |
内科学 | 375篇 |
皮肤病学 | 18篇 |
神经病学 | 181篇 |
特种医学 | 193篇 |
外国民族医学 | 1篇 |
外科学 | 397篇 |
综合类 | 117篇 |
一般理论 | 1篇 |
预防医学 | 206篇 |
眼科学 | 39篇 |
药学 | 205篇 |
中国医学 | 1篇 |
肿瘤学 | 109篇 |
出版年
2022年 | 14篇 |
2021年 | 37篇 |
2020年 | 19篇 |
2019年 | 34篇 |
2018年 | 45篇 |
2017年 | 41篇 |
2016年 | 27篇 |
2015年 | 31篇 |
2014年 | 45篇 |
2013年 | 77篇 |
2012年 | 98篇 |
2011年 | 102篇 |
2010年 | 76篇 |
2009年 | 52篇 |
2008年 | 88篇 |
2007年 | 101篇 |
2006年 | 110篇 |
2005年 | 82篇 |
2004年 | 88篇 |
2003年 | 77篇 |
2002年 | 54篇 |
2001年 | 70篇 |
2000年 | 88篇 |
1999年 | 62篇 |
1998年 | 57篇 |
1997年 | 42篇 |
1996年 | 51篇 |
1995年 | 45篇 |
1994年 | 34篇 |
1993年 | 43篇 |
1992年 | 51篇 |
1991年 | 71篇 |
1990年 | 61篇 |
1989年 | 47篇 |
1988年 | 49篇 |
1987年 | 44篇 |
1986年 | 52篇 |
1985年 | 34篇 |
1984年 | 40篇 |
1983年 | 28篇 |
1982年 | 23篇 |
1981年 | 21篇 |
1980年 | 26篇 |
1979年 | 17篇 |
1978年 | 18篇 |
1976年 | 14篇 |
1975年 | 19篇 |
1974年 | 14篇 |
1972年 | 17篇 |
1968年 | 14篇 |
排序方式: 共有2561条查询结果,搜索用时 15 毫秒
11.
12.
A comparison was made of respiratory function in submersed divers breathing with either a mouthpiece or a full face mask while exposed to varying depths (15 and 190 fsw), exercise loads (0-175 W), and static lung loads (0 and -20 cmH2O). The two types of breathing equipment were designed to be identical in terms of functional dead space volume and resistance to gas flow. When compared with data from experiments utilizing a full face mask, use of a mouthpiece caused a modest fall in expired minute volume at both depths. The majority of this decline may have been the consequence of a decrease in dead space ventilation brought about by the elimination of simultaneous nose breathing and mouth breathing. Alveolar ventilation and PETCO2 were not significantly influenced by the use of a mouthpiece, regardless of depth, workload, or static lung load. With both types of breathing gear episodes of dyspnea were infrequent during experiments with a static lung load of 0 cmH2O. Therefore, if a neutral static lung load is maintained, the type of breathing gear used does not seem to be of consequence as far as dyspnea is concerned. 相似文献
13.
14.
Powders of uncoated disodium fluorescein (DF) and DF coated with various amounts of lauric or capric acids were generated as aerosols in an environment of controlled temperature and relative humidity. The particle size and distribution of these powders were characterized using a cascade impactor and a computerized data inversion method of analysis. Disodium fluorescein exhibited a hygroscopic growth ratio of 1.5 at a relative humidity of 97%. This growth was reduced to 1.3 by coating with 0.15 g of lauric acid or 0.8 g of capric acid per gram of DF, and was eliminated with 0.2 g of lauric acid or 0.18 g of capric acid per gram of DF. The reduction in hygroscopic growth probably reflects an inhibition of the growth rate. In the time following generation and prior to deposition in the collection device, approximately 40 s, the coated aerosol powders do not seem to reach their equilibrium droplet diameter. These studies indicate that these combinations of DF and fatty acid would result in larger equilibrium droplet diameters than that of the dye alone. 相似文献
15.
A comprehensive anatomic and radiographic analysis of the peribursal fat plane in 12 cadavers confirmed that the fat plane seen on radiographs represents extrasynovial fat lining the subacromial bursa and documented the anatomic relations of the bursa. A three-part retrospective clinical evaluation of rotator cuff tears, calcific tendinitis, and rheumatoid arthritis was performed. Two osteoradiologists blindly graded the appearance of the peribursal fat plane with the shoulder in external versus internal rotation in 21 patients with arthrographically intact rotator cuffs and 21 patients with disrupted rotator cuffs. The peribursal fat plane was seen better with disrupted rotator cuffs. The peribursal fat plane was seen better with the shoulder in internal rotation and was seen in 60% of control subjects but only 21% of patients with rotator cuff tears. Partial or complete obliteration of this fat plane is a sensitive (79%) but less specific (60%) indicator of rotator cuff tears. Obliteration of the peribursal fat plane by inflammatory processes in adjacent tissues, including calcific tendinitis and rheumatoid arthritis, occurred with a high frequency. 相似文献
16.
Instrument development: cardiac diet and exercise self-efficacy. 总被引:3,自引:0,他引:3
Self-efficacy has been documented as a strong predictor of health behaviors. Unfortunately, availability of reliable and valid measures of self-efficacy for a range of health behaviors is still limited. This study validated two measures of cardiac risk factor self-efficacy: the Cardiac Diet Self-Efficacy Instrument (CDSEI) and the Cardiac Exercise Self-Efficacy Instrument (CESEI). A sample of 370 cardiac rehabilitation participants provided data for principal factor analyses showing the unidimensionality of each instrument. Known groups construct validity was supported by a comparison of CDSEI and CESEI scores for cardiac rehabilitation participants and marathon runners. The value of CDSEI and CESEI scores in predicting subsequent exercise and diet performance was demonstrated with a third group of cardiac rehabilitation participants. Stability and internal consistency estimates in the .80s and .90s, respectively, support the scales' reliabilities. 相似文献
17.
18.
J.P. Neoptolemos M. G.T. Raraty P. Ghaneh H. Hickey D.D. Stocken J. A. Dunn H. Friess M.W. Büchler 《Der Chirurg》2003,74(3):191-201
Recent advances have been made in the treatment of pancreas cancer. Specialized pancreas centres have reported an increasing rate of resections with reduced postoperative mortality. On account of the highly aggressive nature of pancreas cancer, there is a great challenge in identifying effective therapy concepts for advanced stages of the cancer as well as for the development of resection-associated measures. As large-scale, randomised, controlled studies are lacking, the additive therapy concepts after resection do not have a sufficiently scientific basis. The ESPAC-1 study, which included 600 patients, surpassed all previous studies on adjuvant therapy for pancreas cancer. This study has shown,for example, that the most promising adjuvant chemotherapy with 5-fluorouracil and folic acid leads to an equal if not better result than the multimodal regimen. This regimen can be superseded with the use of Gemcitabine, which will be evaluated in the ESPAC-3 study that includes 990 patients from various European countries including Germany, as well as from Canada and Australia. Participation in the large, phase-3 study therefore plays a key role in the continued development of the management of pancreas cancer. 相似文献
19.
M. O’Mahony R. Conroy E. Shelley N. Hickey A. Radic 《Irish journal of medical science》1991,160(9):17-21
A myocardial infarction and stroke register was established in January 1987 as part of the evaluation of the Kilkenny Health
Project This is a community programme which aims to reduce risk factors for coronary heart disease. The register records acute
myocardial infarction and stroke in residents of County Kilkenny and of the reference county. This will provide accurate estimates
of the incidence of these diseases and of trends over time.
Methods used comply with the protocol in use by the WHO MONICA Project. This will allow comparison of the incidence of coronary
heart disease and stroke in this register with that in other MONICA locations, including that in Belfast, Northern Ireland. 相似文献
20.
Pulmonary artery sling with tracheal stenosis is a difficult management problem. We describe the use of cardiopulmonary bypass as a method to facilitate one-stage repair. 相似文献