全文获取类型
收费全文 | 2458篇 |
免费 | 337篇 |
国内免费 | 48篇 |
专业分类
耳鼻咽喉 | 26篇 |
儿科学 | 132篇 |
妇产科学 | 28篇 |
基础医学 | 200篇 |
口腔科学 | 35篇 |
临床医学 | 357篇 |
内科学 | 735篇 |
皮肤病学 | 72篇 |
神经病学 | 273篇 |
特种医学 | 311篇 |
外科学 | 279篇 |
综合类 | 40篇 |
预防医学 | 113篇 |
眼科学 | 24篇 |
药学 | 133篇 |
中国医学 | 1篇 |
肿瘤学 | 84篇 |
出版年
2023年 | 59篇 |
2022年 | 19篇 |
2021年 | 35篇 |
2020年 | 100篇 |
2019年 | 18篇 |
2018年 | 104篇 |
2017年 | 78篇 |
2016年 | 81篇 |
2015年 | 70篇 |
2014年 | 108篇 |
2013年 | 135篇 |
2012年 | 88篇 |
2011年 | 67篇 |
2010年 | 89篇 |
2009年 | 120篇 |
2008年 | 76篇 |
2007年 | 79篇 |
2006年 | 71篇 |
2005年 | 54篇 |
2004年 | 39篇 |
2003年 | 52篇 |
2002年 | 40篇 |
2001年 | 66篇 |
2000年 | 32篇 |
1999年 | 50篇 |
1998年 | 88篇 |
1997年 | 110篇 |
1996年 | 88篇 |
1995年 | 77篇 |
1994年 | 55篇 |
1993年 | 56篇 |
1992年 | 36篇 |
1991年 | 25篇 |
1990年 | 38篇 |
1989年 | 62篇 |
1988年 | 59篇 |
1987年 | 40篇 |
1986年 | 32篇 |
1985年 | 35篇 |
1984年 | 25篇 |
1983年 | 16篇 |
1982年 | 20篇 |
1981年 | 18篇 |
1980年 | 16篇 |
1979年 | 17篇 |
1978年 | 19篇 |
1977年 | 13篇 |
1976年 | 18篇 |
1971年 | 13篇 |
1968年 | 10篇 |
排序方式: 共有2843条查询结果,搜索用时 10 毫秒
1.
2.
3.
4.
P Helwig G Faust U Hindenlang B Kr?plin C Eingartner 《Technology and health care》2006,14(4-5):411-419
Static analysis with finite element of a realistic femur nail bone-implant system in a typical proximal femoral fracture under physiological load bearing situations provides results for stress, displacement and strain. The question to be answered is, if simulation with the finite element analysis is able to explain biomechanically clinical observed patterns of failure. Surface-Reconstruction with CT database of a proximal femur and reconstruction with CT based density data was done. Next steps were to unite the bone structure with the Proximal Femoral Nail and to model two relevant fractures (31-A2.2 and A2.3 according AO). After modelling of geometry, isotropic material behaviour and load application numeric calculation of the femur-nail system with FE-software was performed. FE simulation mainly shows an axial dislocation of the femoral head screw with nearly no dislocation of the antirotation screw. This so-called z-effect therefore means: (1) Tilting of the proximal main fragment around the sagittal axis between the screws and (2) relative movement of both screws in the frontal plane. Relative movement of the two screws against each other could be the reason for implant failure, the so called cut out. Furthermore simulation shows different gliding of the screws explaining the so called z-telescoping. The analyzed stress patterns have to be relativized, because isotropic material behaviour of cancellous bone was assumed. Further examinations for this issue are necessary. 相似文献
5.
6.
M A Keller J Faust L J Rolewic D D Stewart 《Journal of pediatric gastroenterology and nutrition》1986,5(3):439-443
Lymphocytes from 10 paired colostrum and peripheral blood specimens were examined to determine if the colostral T cell population differs from the peripheral blood T cell population in subset distribution. The percentages of lymphocytes staining with OKT3, OKT4, and OKT8 murine monoclonal antibody were determined. Lymphocytes from colostrum were 74.7 +/- 2.5% OKT3+, 50.6 +/- 2.3% OKT4+, 24.0 +/- 1.7% OKT8+, whereas peripheral blood lymphocytes were 78.7 +/- 1.9% OKT3+, 48.4 +/- 1.4% OKT4+, and 29.8 +/- 1.6% OKT8+. The percentage of colostrum lymphocytes positive for OKT3 was significantly although not strikingly lower than the OKT3 percentage for blood lymphocytes (p less than 0.05). This difference was due to the lower percentage of OKT8 positive lymphocytes in colostrum compared with blood (p less than 0.01). Although the T cell subset distribution of colostrum generally appears to be similar to that in the peripheral blood, there were small differences in OKT3 and OKT8 percentages that were statistically significant suggesting the possibility of some selectivity of the colostral T cell population. 相似文献
7.
8.
We examine major criticisms of studies comparing paraprofessionals' and professionals' therapeutic effectiveness. Such analysis does not support the contention that methodological weaknesses of the studies produced systematic biases against professional therapists. Thus, despite common beliefs to the contrary, the finding that formal training does not predict successful therapy appears sound. We discuss the implications of this finding for research, training, and clinical practice. 相似文献
9.
10.
Algal toxicity of binary combinations of pesticides 总被引:5,自引:0,他引:5