全文获取类型
收费全文 | 2120篇 |
免费 | 166篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 58篇 |
妇产科学 | 54篇 |
基础医学 | 338篇 |
口腔科学 | 21篇 |
临床医学 | 230篇 |
内科学 | 426篇 |
皮肤病学 | 54篇 |
神经病学 | 200篇 |
特种医学 | 48篇 |
外科学 | 153篇 |
综合类 | 12篇 |
一般理论 | 2篇 |
预防医学 | 253篇 |
眼科学 | 22篇 |
药学 | 241篇 |
中国医学 | 2篇 |
肿瘤学 | 170篇 |
出版年
2023年 | 27篇 |
2022年 | 54篇 |
2021年 | 110篇 |
2020年 | 69篇 |
2019年 | 76篇 |
2018年 | 92篇 |
2017年 | 68篇 |
2016年 | 62篇 |
2015年 | 82篇 |
2014年 | 89篇 |
2013年 | 143篇 |
2012年 | 188篇 |
2011年 | 198篇 |
2010年 | 96篇 |
2009年 | 84篇 |
2008年 | 105篇 |
2007年 | 111篇 |
2006年 | 119篇 |
2005年 | 110篇 |
2004年 | 94篇 |
2003年 | 89篇 |
2002年 | 61篇 |
2001年 | 15篇 |
2000年 | 6篇 |
1999年 | 8篇 |
1998年 | 13篇 |
1997年 | 5篇 |
1996年 | 5篇 |
1995年 | 10篇 |
1994年 | 3篇 |
1992年 | 6篇 |
1991年 | 10篇 |
1990年 | 6篇 |
1989年 | 3篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1984年 | 3篇 |
1983年 | 5篇 |
1982年 | 3篇 |
1981年 | 4篇 |
1978年 | 5篇 |
1971年 | 3篇 |
1959年 | 2篇 |
1954年 | 3篇 |
1932年 | 2篇 |
1930年 | 2篇 |
1929年 | 2篇 |
1927年 | 2篇 |
1921年 | 2篇 |
排序方式: 共有2292条查询结果,搜索用时 125 毫秒
151.
Background
Children's independent mobility differs between groups of adolescents, but knowledge is lacking on how mobility-limiting factors interact. This study explores the association between factors that can affect young adolescents' mobility, searching for typical patterns within a geographical area where mobility is both relatively high and promoted (in this case Stockholm County, Sweden). An additional question is how clusters of limiting factors and demographic attributes relate to active commuting to school. 相似文献152.
153.
Oral contraceptive use and bone mineral density in premenopausal women: cross-sectional, population-based data from the Canadian Multicentre Osteoporosis Study 总被引:6,自引:0,他引:6 下载免费PDF全文
154.
Background
The association between cardiovascular mortality and winter cold spells was evaluated in the population of the Czech Republic over 21-yr period 1986–2006. No comprehensive study on cold-related mortality in central Europe has been carried out despite the fact that cold air invasions are more frequent and severe in this region than in western and southern Europe. 相似文献155.
Lucie Lamontagne Suzanne Lusignan Christian Page 《Clinical immunology (Orlando, Fla.)》2001,101(3):345
Mouse hepatitis virus (MHV) provides an excellent animal model for the study of the immunopathological mechanisms involved in hepatic viral diseases. We previously generated an attenuated viral variant, YAC-MHV3, which induces a subclinical disease and recovery within 15 days. In contrast, the L2-MHV3 strain induces the development of a fulminant hepatitis, leading to death within 3 days. In this paper, we document intrahepatic and splenic T cell subpopulations involved in the hepatitis process and viral elimination identified in attenuated or pathogenic MHV3-infected C57BL/6 mice. Percentages of intrahepatic CD4+ cells decreased in attenuated YAC-MHV3-infected mice, while they increased in mice infected with pathogenic L2-MHV3, compared with uninfected animals. Moreover, in YAC-MHV3-infected mice, the percentages of intrahepatic CD8+ cells slightly decreased at 24 h pi, then increased until 15 days pi. In contrast, the CD4/CD8 ratios of splenic lymphoid subpopulations increased in the first days of infection and returned to normal values at 15 days pi. Intrahepatic NK1.1+αβ − TCRinter cells decreased in both virally infected groups of mice, while CD4+αβ − TCRinter LFA-1high cells increased in L2-MHV3-infected mice, in contrast with what was seen in YAC-MHV3-infected mice. However, these cells became anergic following Con A or PHA stimulation. Ex vivo studies showed that only the intrahepatic CD8+ cells that were increased in YAC-MHV3-infected mice could be stimulated by lectins. In addition, in vitro viral infections revealed that L2-MHV3 viral infection led to an increase of intrahepatic CD4+αβ − TCRinter cells in the absence of CD8+ cells only. These results indicate that the attenuated phenotype of the YAC-MHV3 virus is related to two different mechanisms: the first involves no increase of intrahepatic CD4+αβ − TCRinter or NK-T cells, while the second favors the recruitment and activation of CD8+ cells in liver. The results are discussed in relation to the integrity of intrahepatic immune tolerance mechanisms and immune-mediated viral elimination. 相似文献
156.
L Rychetnik M Frommer P Hawe A Shiell 《Journal of epidemiology and community health》2002,56(2):119-127
157.
158.
Michael Ith Peter Bigler Eva Scheurer Roland Kreis Lucie Hofmann Richard Dirnhofer Chris Boesch 《Magnetic resonance in medicine》2002,48(5):915-920
Postmortem decomposition of brain tissue was investigated by (1)H-magnetic resonance spectroscopy (MRS) in a sheep head model and selected human cases. Aiming at the eventual estimation of postmortem intervals in forensic medicine, this study focuses on the characterization and identification of newly observed metabolites. In situ single-voxel (1)H-MRS at 1.5 T was complemented by multidimensional homo- and heteronuclear high-resolution NMR spectroscopy of an extract of sheep brain tissue. The inclusion of spectra of model solutions in the program LC Model confirmed the assignments in situ. The first postmortem phase was characterized mainly by changes in the concentrations of metabolites usually observed in vivo and by the appearance of previously reported decay products. About 3 days postmortem, new metabolites, including free trimethylammonium, propionate, butyrate, and iso-butyrate, started to appear in situ. Since the observed metabolites and the time course is comparable in sheep and human brain tissue, the model system seems to be appropriate. 相似文献
159.
Sylvie Perreault Alice Dragomir Lucie Blais Anick Bérard Lyne Lalonde Michel White Danielle Pilon 《European journal of clinical pharmacology》2009,65(10):1013-1024
Background
Statins reduce cardiovascular morbidity and mortality after continuous treatment. Studies have shown that less than 50% of patients take 80% or more of prescribed doses 1 year after starting therapy. 相似文献160.
Forouzan Rezapur-Shahkolai Mohsen Naghavi Mohammadreza Shokouhi Lucie Laflamme 《BMC public health》2008,8(1):269