全文获取类型
收费全文 | 1132篇 |
免费 | 41篇 |
国内免费 | 65篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 55篇 |
妇产科学 | 10篇 |
基础医学 | 80篇 |
口腔科学 | 37篇 |
临床医学 | 152篇 |
内科学 | 235篇 |
皮肤病学 | 23篇 |
神经病学 | 22篇 |
特种医学 | 272篇 |
外科学 | 65篇 |
综合类 | 33篇 |
预防医学 | 39篇 |
眼科学 | 97篇 |
药学 | 50篇 |
肿瘤学 | 65篇 |
出版年
2021年 | 8篇 |
2018年 | 5篇 |
2017年 | 5篇 |
2016年 | 6篇 |
2015年 | 16篇 |
2014年 | 15篇 |
2013年 | 27篇 |
2012年 | 17篇 |
2011年 | 12篇 |
2010年 | 31篇 |
2009年 | 46篇 |
2008年 | 16篇 |
2007年 | 59篇 |
2006年 | 24篇 |
2005年 | 19篇 |
2004年 | 17篇 |
2003年 | 11篇 |
2002年 | 15篇 |
2001年 | 19篇 |
2000年 | 13篇 |
1999年 | 21篇 |
1998年 | 61篇 |
1997年 | 73篇 |
1996年 | 71篇 |
1995年 | 59篇 |
1994年 | 45篇 |
1993年 | 52篇 |
1992年 | 28篇 |
1991年 | 21篇 |
1990年 | 15篇 |
1989年 | 46篇 |
1988年 | 28篇 |
1987年 | 48篇 |
1986年 | 22篇 |
1985年 | 32篇 |
1984年 | 28篇 |
1983年 | 31篇 |
1982年 | 25篇 |
1981年 | 21篇 |
1980年 | 21篇 |
1979年 | 6篇 |
1978年 | 15篇 |
1977年 | 14篇 |
1976年 | 8篇 |
1975年 | 6篇 |
1973年 | 9篇 |
1972年 | 5篇 |
1971年 | 6篇 |
1967年 | 6篇 |
1966年 | 6篇 |
排序方式: 共有1238条查询结果,搜索用时 15 毫秒
11.
β-Lactoglobulin was isolated from infant formulae that were ultra high temperature (UHT) -treated, sterilized or spray-dried. The effect of the isolated β-lactoglobulin on SfaII-fimbriae-mediated adhesion of Escherichia coli to human ileostomy glycoproteins was studied in vitro. β-Lactoglobulin isolated from sterilized formulae was found to perform significantly less well than preparations from spray-dried formulae (p = 0:05). Great heterogeneity was observed in the adhesion inhibitory capacity of β-lactoglobulin isolated from UHT-treated formulae. Therefore, no significant difference was observed between UHT-treated and sterilized formulae or spray-dried formulae (p < 0:10). It can be hypothesized that β-lactoglobulin from spray-dried and some UHT-treated infant formulae may affect the colonization of mucous membranes by E. coli strains causing neonatal septicaemia and meningitis. 相似文献
12.
13.
14.
15.
CTLA-4 is required for the induction of high dose oral tolerance 总被引:5,自引:3,他引:5
Samoilova EB; Horton JL; Zhang H; Khoury SJ; Weiner HL; Chen Y 《International immunology》1998,10(4):491-498
Mucosal and systemic administrations of high dose antigens induce long-
lasting peripheral T cell tolerance. We and others have shown that high
dose peripheral T cell tolerance is mediated by anergy or deletion and is
preceded by T cell activation. Co-stimulatory molecules B7-1 (CD80)/B7-2
(CD86) and their counter-receptors CD28/CTLA-4 play pivotal roles in T cell
activation and immune regulation. In the present study, we examined the
roles of the B7 co-stimulation pathway in the generation of high dose
peripheral T cell tolerance. We found that blocking B7:CD28/CTLA-4
interaction at the time of tolerance induction partially prevented T cell
tolerance, whereas selective blockade of B7:CTLA-4 interaction completely
abrogated peripheral T cell tolerance induced by either oral or i.p.
antigens. These results suggest that CTLA-4-mediated feedback regulation
plays a crucial role in the induction of high dose peripheral T cell
tolerance.
相似文献
16.
Preimplantation genetic diagnosis principles and ethics 总被引:4,自引:0,他引:4
17.
Life expectancy in British Marfan syndrome populations 总被引:2,自引:0,他引:2
JR Gray AB Bridges RR West L. McLeish AG Stuart JCS Dean MEM Porteous M. Boxer SJ Davies 《Clinical genetics》1998,54(2):124-128
A total of 206 patients with Marfan syndrome were ascertained throughout genetic clinics in Wales and Scotland during the period 1970–1990. There were 45 deaths representing 22% of the cohort. Mean age at death was 45.3 ± 16.5 years. 50% median cumulative survival in the total cohort (n = 206) was 53 years for males and 72 years for females. Multivariate analysis confirmed severity as the best independent indicator of survival. These findings and survival curves will assist in the counselling of British families and individuals with Marfan syndrome. 相似文献
18.
Frataxin is reduced in Friedreich ataxia patients and is associated with mitochondrial membranes 总被引:17,自引:8,他引:17
Campuzano V; Montermini L; Lutz Y; Cova L; Hindelang C; Jiralerspong S; Trottier Y; Kish SJ; Faucheux B; Trouillas P; Authier FJ; Durr A; Mandel JL; Vescovi A; Pandolfo M; Koenig M 《Human molecular genetics》1997,6(11):1771-1780
Friedreich ataxia is a progressive neurodegenerative disorder caused by
loss of function mutations in the frataxin gene. In order to unravel
frataxin function we developed monoclonal antibodies raised against
different regions of the protein. These antibodies detect a processed 18
kDa protein in various human and mouse tissues and cell lines that is
severely reduced in Friedreich ataxia patients. By immunocytofluorescence
and immunocytoelectron microscopy we show that frataxin is located in
mitochondria, associated with the mitochondrial membranes and crests.
Analysis of cellular localization of various truncated forms of frataxin
expressed in cultured cells and evidence of removal of an N-terminal
epitope during protein maturation demonstrated that the mitochondrial
targetting sequence is encoded by the first 20 amino acids. Given the
shared clinical features between Friedreich ataxia, vitamin E deficiency
and some mitochondriopathies, our data suggest that a reduction in frataxin
results in oxidative damage.
相似文献
19.
Recessively inherited L-DOPA-responsive parkinsonism in infancy caused by a point mutation (L205P) in the tyrosine hydroxylase gene 总被引:4,自引:0,他引:4
20.