全文获取类型
收费全文 | 1370篇 |
免费 | 72篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 82篇 |
妇产科学 | 30篇 |
基础医学 | 160篇 |
口腔科学 | 45篇 |
临床医学 | 101篇 |
内科学 | 296篇 |
皮肤病学 | 24篇 |
神经病学 | 33篇 |
特种医学 | 427篇 |
外科学 | 85篇 |
综合类 | 47篇 |
预防医学 | 32篇 |
眼科学 | 6篇 |
药学 | 39篇 |
1篇 | |
肿瘤学 | 30篇 |
出版年
2023年 | 4篇 |
2022年 | 3篇 |
2021年 | 4篇 |
2020年 | 5篇 |
2019年 | 6篇 |
2018年 | 9篇 |
2017年 | 14篇 |
2016年 | 10篇 |
2015年 | 13篇 |
2014年 | 30篇 |
2013年 | 33篇 |
2012年 | 16篇 |
2011年 | 20篇 |
2010年 | 34篇 |
2009年 | 53篇 |
2008年 | 23篇 |
2007年 | 38篇 |
2006年 | 29篇 |
2005年 | 25篇 |
2004年 | 22篇 |
2003年 | 20篇 |
2002年 | 11篇 |
2001年 | 26篇 |
2000年 | 12篇 |
1999年 | 18篇 |
1998年 | 79篇 |
1997年 | 79篇 |
1996年 | 79篇 |
1995年 | 64篇 |
1994年 | 39篇 |
1993年 | 58篇 |
1992年 | 6篇 |
1991年 | 13篇 |
1990年 | 25篇 |
1989年 | 53篇 |
1988年 | 44篇 |
1987年 | 46篇 |
1986年 | 54篇 |
1985年 | 68篇 |
1984年 | 36篇 |
1983年 | 31篇 |
1982年 | 29篇 |
1981年 | 31篇 |
1980年 | 37篇 |
1979年 | 6篇 |
1978年 | 19篇 |
1977年 | 24篇 |
1976年 | 21篇 |
1975年 | 20篇 |
1914年 | 1篇 |
排序方式: 共有1446条查询结果,搜索用时 15 毫秒
991.
Anteroposterior angulated view. A new radiographic technique for the evaluation of spondylolysis 总被引:1,自引:0,他引:1
A 30 degrees cranial angulated view for the evaluation of spondylolysis demonstrates the pars interarticularis with minimal distortion and without being obscured by overlying bony structures. The degree of callous formation and bony union can be assessed. 相似文献
992.
993.
994.
995.
996.
997.
A noncomputerized, count-based technique for the determination of left ventricular ejection fraction (LVEF), which does not use geometric assumptions of left ventricular shape, was developed. The noncomputerized technique and computerized multigated ventriculography using both fixed and variable region-of-interest (ROI) methods were performed on 16 patients. The LVEFs obtained with the noncomputerized technique correlated well with both the fixed ROI computerized technique (r = .87) and the variable ROI computerized technique (r = .86). It is concluded that when a computer is not available, the noncomputerized technique is a valid alternative for the determination of LVEF in resting patients in stable sinus rhythm. 相似文献
998.
999.
1000.
The acid deoxyribonuclease of neutrophils: a possible participant in apoptosis-associated genome destruction 总被引:5,自引:0,他引:5
Human neutrophils are terminally differentiated cells that spontaneously undergo apoptosis in tissue culture. Apoptosis in these cells can be delayed by culture in the presence of granulocyte colony- stimulating factor or other inflammatory mediators. Neutrophils were found to contain an acid endonuclease that appeared to be responsible for the internucleosomal DNA cleavage that accompanies apoptosis. As measured by a plasmid nicking assay, this endonuclease had a molecular weight (M(r)) of 35,000, a pH optimum of 5.5, and a threshold for activity of pH 6.6 to 6.8. It was weakly inhibited by divalent cations (Ca2+, Mg2+, and Zn2+) and more strongly inhibited by aurintricarboxylic acid and N-bromosuccinimide. DNA from neutrophils treated with nigericin in buffers of defined pH displayed nucleosomal ladders whose prominence varied with pH in a manner that paralleled the pH dependence of the plasmid cleavage assays, consistent with internucleosomal DNA cleavage by the acid endonuclease. We have previously shown that neutrophils undergo acidification to a pH value as low as 6.0 during apoptosis; we suggest that this endonuclease may be responsible for the DNA cleavage seen in apoptotic neutrophils. 相似文献