全文获取类型
收费全文 | 1091篇 |
免费 | 65篇 |
国内免费 | 23篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 70篇 |
妇产科学 | 9篇 |
基础医学 | 115篇 |
口腔科学 | 47篇 |
临床医学 | 164篇 |
内科学 | 192篇 |
皮肤病学 | 13篇 |
神经病学 | 52篇 |
特种医学 | 154篇 |
外科学 | 134篇 |
综合类 | 10篇 |
一般理论 | 1篇 |
预防医学 | 91篇 |
眼科学 | 6篇 |
药学 | 66篇 |
肿瘤学 | 51篇 |
出版年
2021年 | 11篇 |
2019年 | 12篇 |
2018年 | 14篇 |
2017年 | 12篇 |
2016年 | 12篇 |
2015年 | 21篇 |
2014年 | 27篇 |
2013年 | 48篇 |
2012年 | 39篇 |
2011年 | 47篇 |
2010年 | 44篇 |
2009年 | 33篇 |
2008年 | 28篇 |
2007年 | 44篇 |
2006年 | 35篇 |
2005年 | 32篇 |
2004年 | 24篇 |
2003年 | 16篇 |
2002年 | 23篇 |
2001年 | 17篇 |
2000年 | 17篇 |
1999年 | 27篇 |
1998年 | 46篇 |
1997年 | 48篇 |
1996年 | 42篇 |
1995年 | 24篇 |
1994年 | 32篇 |
1993年 | 21篇 |
1992年 | 25篇 |
1991年 | 20篇 |
1990年 | 26篇 |
1989年 | 24篇 |
1988年 | 37篇 |
1987年 | 20篇 |
1986年 | 25篇 |
1985年 | 22篇 |
1984年 | 15篇 |
1983年 | 23篇 |
1982年 | 19篇 |
1981年 | 12篇 |
1980年 | 11篇 |
1978年 | 6篇 |
1977年 | 7篇 |
1976年 | 10篇 |
1975年 | 5篇 |
1974年 | 5篇 |
1973年 | 6篇 |
1971年 | 9篇 |
1970年 | 8篇 |
1967年 | 6篇 |
排序方式: 共有1179条查询结果,搜索用时 15 毫秒
1.
2.
Factors influencing women to undergo screening mammography 总被引:2,自引:0,他引:2
3.
Braffman BH; Coleman BG; Ramchandani P; Arger PH; Nodine CF; Dinsmore BJ; Louie A; Betsch SE 《Radiology》1994,190(3):797
4.
J C Cavanaugh 《International journal of aging & human development》1986,24(4):271-277
Self-reports of memory abilities and skills were obtained from fifty younger (M = 20.2) and fifty older (M = 68.7) adults. General rating questions (e.g., How good do you feel your memory is?) and specific questions about memory for certain types of content (e.g., people's names) were included. Consistent age-related decrements were found only for general questions, especially those assessing perceived changes over time. Less consistent differences were found for specific questions. Results were interpreted in terms of implications for assessing self-reported memory ability, and in terms of their meaning for research on the relationship between self-reported and actual memory ability. 相似文献
5.
6.
Rupture of the distal biceps tendon: evaluation with MR imaging 总被引:2,自引:0,他引:2
7.
Role of drug-abuse treatment in limiting the spread of AIDS 总被引:10,自引:0,他引:10
R L Hubbard M E Marsden E Cavanaugh J V Rachal H M Ginzburg 《Reviews of infectious diseases》1988,10(2):377-384
8.
P. F. Cavanaugh J. S. Mcdonald L. Pavelic R. J. Limardi J. L. Gluckman Z. P. Pavelic 《Inflammopharmacology》1995,3(2):109-119
Prostaglandins are inflammatory mediators that are believed to play an important role in the pathophysiology of periodontal
disease. Prostaglandin H synthase (PGHS, EC 1.14.99.1) is the rate-limiting enzyme in prostaglandin biosynthesis. The enzyme
exists as two separately encoded isoforms. PGHS-1 which is constitutively expressed and PGHS-2 which is induced by inflammatory
stimuli. This is the first report describing the expression of the isoenzymes in gingival tissue from patients diagnosed with
adult periodontitis. Tissue was fixed in an alcohol-based fixative and embedded in paraffin. Methods were developed using
immunohistochemical controls, such that embedded sections could be processed and stained using isoform-specific antibodies
and a peroxidase-antiperoxidase immunohistochemistry technique. Along with populations of mononuclear inflammatory cells,
endothelial cells and fibroblasts, the gingival epithelial cell layer appears to be a rich and important source of prostaglandin
production within the periodontium of patients with periodontitis as detected by this newly developed immunohistochemical
staining technique for PGHS-1 and PGHS-2. 相似文献
9.
Duncan PW Chandler JM Cavanaugh DK Johnson KR Buehler AG 《The Journal of orthopaedic and sports physical therapy》1989,11(2):70-75
This research was supported by a Duke University Research Council Grant. The purpose of this study was to examine mode and speed specificity of strength training by comparing concentric and eccentric isokinetic exercise of the quadriceps. Forty-eight healthy men (mean age = 23.9 years) were randomly assigned to one of three groups: concentric training (C), eccentric training (E), or control (K). Average force (in Newtons) of 3 concentric and of 3 eccentric quadriceps contractions on the KIN-COM(R) dynamometer at 60, 120, and 180 degrees /sec was evaluated prior to and following a 6 week period during which only the C and E groups trained. Training sessions (3/week) included 4 submaximal and 1 maximal warm-up followed by 10 maximal effort isokinetic contractions of the quadriceps at 120 degrees /sec for each leg. Group C subjects trained concentrically only while Group E subjects trained eccentrically only. A t-test for independent means showed no significant right/left differences. ANOVA and Scheffe's F-tests were then used to assess the differences in training effects among the 3 groups for the left leg only. Results showed that although Group C increased slightly in both concentric and eccentric force at all speeds, the gains were significant only for concentric force at 180 degrees /sec. Group E showed significant gains (p < 0.05) in eccentric force at all speeds but not in concentric force. The K group had no significant change in concentric or eccentric force at any speed. We conclude that the eccentric mode of isokinetic exercise has highly specific strength training effects while the concentric mode has less specific training effects. In addition, speed of exercise does not appear to have specific training effects. J Orthop Sports Phys Ther 1989;11(2):70-75. 相似文献
10.
Kallakuri S Cavanaugh JM Ozaktay AC Takebayashi T 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》2003,148(4):419-424
Diffuse axonal injury (DAI) is seen as widespread damage in the white matter of brain characterized by morphological changes
to axons throughout the brain and brain stem. The current study attempted to investigate the effect of increasing impact energy
on the presence and severity of DAI in corpus callosum (CC). DAI was induced in adult male Sprague-Dawley rats using an injury
model adapted from Marmarou et al. in 1994. A 450-g cylindrical brass weight was dropped from three different heights (2.0 m,
1.5 m and 1.0 m) on to a metal helmet affixed to the skull of the rats. In the sham group, rats underwent a surgical procedure
with no impact. After a 24-h survival period the animals were transcardially perfused. The brain was removed and the cerebral
hemispheres were sectioned with a vibrotome and stained by silver impregnation technique. The CC of all the impacted rats
showed DAI in the form of beaded axons, retraction balls and vacuole-like enlargements. The axonal injury was most severe
in the 2-m group, while mildest in the 1-m group. In the sham group, axons appeared to be normal. This study demonstrates
evidence of graded DAI depending on the impact energy. Such data is useful for mathematical modeling of axonal injury in rat
brain using the same impact parameters and potential determination of injury thresholds for neural trauma.
Electronic Publication 相似文献