全文获取类型
收费全文 | 624篇 |
免费 | 22篇 |
国内免费 | 27篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 36篇 |
妇产科学 | 2篇 |
基础医学 | 27篇 |
口腔科学 | 9篇 |
临床医学 | 62篇 |
内科学 | 125篇 |
皮肤病学 | 9篇 |
神经病学 | 20篇 |
特种医学 | 134篇 |
外科学 | 98篇 |
综合类 | 29篇 |
预防医学 | 22篇 |
眼科学 | 29篇 |
药学 | 33篇 |
肿瘤学 | 37篇 |
出版年
2022年 | 2篇 |
2020年 | 3篇 |
2019年 | 6篇 |
2018年 | 13篇 |
2017年 | 5篇 |
2016年 | 7篇 |
2015年 | 9篇 |
2014年 | 14篇 |
2013年 | 18篇 |
2012年 | 14篇 |
2011年 | 13篇 |
2010年 | 14篇 |
2009年 | 16篇 |
2008年 | 17篇 |
2007年 | 37篇 |
2006年 | 32篇 |
2005年 | 13篇 |
2004年 | 13篇 |
2003年 | 16篇 |
2002年 | 13篇 |
2001年 | 24篇 |
2000年 | 12篇 |
1999年 | 17篇 |
1998年 | 37篇 |
1997年 | 22篇 |
1996年 | 29篇 |
1995年 | 23篇 |
1994年 | 20篇 |
1993年 | 22篇 |
1992年 | 17篇 |
1991年 | 9篇 |
1990年 | 21篇 |
1989年 | 12篇 |
1988年 | 14篇 |
1987年 | 9篇 |
1986年 | 13篇 |
1985年 | 11篇 |
1984年 | 12篇 |
1983年 | 8篇 |
1982年 | 7篇 |
1981年 | 8篇 |
1980年 | 14篇 |
1979年 | 4篇 |
1978年 | 4篇 |
1977年 | 4篇 |
1976年 | 6篇 |
1975年 | 4篇 |
1974年 | 5篇 |
1970年 | 2篇 |
1969年 | 4篇 |
排序方式: 共有673条查询结果,搜索用时 15 毫秒
1.
Helen J. Michielsen Marcel A. Croon Tineke M. Willemsen Jolanda De Vries Guus L. Van Heck 《Stress and health》2007,23(2):121-130
The main objective of this study was to examine the psychosocial stress model developed by Taylor and Aspinwall with emotional exhaustion as the outcome variable. Respondents, 409 men and 346 women, who had a paid job for at least 20 hours per week, completed questionnaires concerning demographic variables, personality, temperament, work pressure, workload, perceived social support, appraisal, coping, and emotional exhaustion. Structural equation analyses provided only partial support for the validity of the model. First, on theoretical and statistical grounds, one more path linking external resources to social support was added. Second, contrary to expectations, coping styles did not predict emotional exhaustion. To conclude, when coping is measured retrospectively, it does not add to our understanding of emotional exhaustion. It is suggested that future studies should be longitudinal and include objective measures of stressors and psychosocial health outcomes in addition to self‐reports. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
2.
ZQ Yin MD SG Crewther PhD B Pirie BSc DP Crewther PhD 《Clinical & experimental ophthalmology》1997,25(4):107-109
Purpose: It was investigated whether alterations in neuronal structure and function occasioned by strabismic amblyopia also may be reflected in alterations in the expression on Y type neurons of a Cat-301 antibody sensitive antigen in the lateral geniculate nucleus (LGN) and cortex of our cat model of strabismic amblyopia. Methods/Results: The percentage of positively labelled cells was reduced in LGN laminae that received input from the deviated eye in strabismic amblyopic cats compared with normal cats. In the strabismic cortex, the density of immunopositive neurons was significantly reduced compared with normal, the effect being most pronounced in layer IV Conclusions: Despite previous physiological recordings indicating a decrease in X-cell associated acuity in strabismic amblyopia, the present findings imply that the changes in the early visual experience occasioned by strabismus also produce specific molecular changes in theY neuronal class. 相似文献
3.
4.
5.
6.
R Meeuwis R Michielsen E Decuypere E R Kühn 《General and comparative endocrinology》1989,76(3):357-363
An injection of several doses of ovine corticotropin-releasing factor (oCRF) was made into an allantoic blood vessel of 18-day-old chick embryos. All doses used (0.5, 1, 2, and 5 micrograms) induce a quick increase of plasma corticosterone concentrations after 15 and 30 min and 1 and 2 hr and this in a dose-dependent manner with the high doses having a prolonged effect lasting up to 2 hr. An increase in plasma levels of thyroxine (T4) and triiodothyronine (T3) was observed after 1 and 2 hr. After the oCRF injection, no stimulation of the hepatic 5'-monodeiodination activity was observed and there was no increase, but even a small decrease in the T3 to T4 ratio could be calculated. It was therefore concluded that oCRF in the chick embryo has a thyrotropic effect presumably by stimulating the release of thyrotropin from the pituitary. 相似文献
7.
8.
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
9.
We report two cases of Sneddon's syndrome. Both cases had widespread livedo reticularis with repeated cerebrovascular accidents without persistent neurological deficit. In one case, hemostatic examination revealed an imbalance of plasminogen activator-inhibitor values, possibly related to the thrombogenic propensity of the syndrome. Treatment with acetylsalicylic acid led to normalization of hemostatic parameters and resulted in a symptom-free period of more than 10 months. The importance of hemostatic screening in patients with Sneddon's syndrome is discussed. 相似文献
10.
AJK WILLIAMS R FRASER DP CHORLEY J DENT 《Journal of gastroenterology and hepatology》1996,11(5):500-505
Safe placement of nasogastric tubes requires reliable positioning of the tip of the tube within the stomach. Radiology and aspiration are currently used to confirm tube position, but suffer from significant problems of cost and efficacy, respectively. We have developed a novel method to locate the position of a catheter tip within the body, using the detection of a low energy electromagnetic field generated in a coil located in the catheter with an external hand-held unit (Cathlocator). In vitro, the unit detected the distance of the coil from the detector with an accuracy of 0.1 cm over a range of 4–12 cm. In vivo studies were performed in 11 healthy volunteers using a purpose-built manometric assembly that incorporated the signal generating coil in its tip. In all subjects the Cathlocator showed the position of the signal generating coil to be cranial to the xiphisternum when manometric and transmucosal potential difference criteria showed it to be located above the lower oesophageal sphincter. When the coil was within the stomach, the Cathlocator identified its position within the epigastric, umbilical and left hypochondrial regions of the abdomen. The distance of the coil from the surface was significantly greater when in the duodenum mean (±s.e.m. 7.6±0.3 cm; P<0.001) and oesophagus (8.6±0.2 cm; P<0.002) than the stomach (5.0±0.4 cm). In one subject studied twice there was a close correlation between the location and depth measured by the device on each occasion. The Cathlocator is a novel non-radiological device that has the potential to be useful in the placement of gastrointestinal catheters. 相似文献