全文获取类型
收费全文 | 2254941篇 |
免费 | 185623篇 |
国内免费 | 4161篇 |
专业分类
耳鼻咽喉 | 32099篇 |
儿科学 | 71799篇 |
妇产科学 | 65168篇 |
基础医学 | 322768篇 |
口腔科学 | 66991篇 |
临床医学 | 200993篇 |
内科学 | 434947篇 |
皮肤病学 | 47355篇 |
神经病学 | 183695篇 |
特种医学 | 90487篇 |
外国民族医学 | 633篇 |
外科学 | 344625篇 |
综合类 | 59085篇 |
现状与发展 | 5篇 |
一般理论 | 788篇 |
预防医学 | 177081篇 |
眼科学 | 52631篇 |
药学 | 170225篇 |
2篇 | |
中国医学 | 4300篇 |
肿瘤学 | 119048篇 |
出版年
2018年 | 21033篇 |
2015年 | 21498篇 |
2014年 | 29961篇 |
2013年 | 45742篇 |
2012年 | 61754篇 |
2011年 | 65017篇 |
2010年 | 38246篇 |
2009年 | 36294篇 |
2008年 | 61801篇 |
2007年 | 65991篇 |
2006年 | 66406篇 |
2005年 | 64810篇 |
2004年 | 63710篇 |
2003年 | 61065篇 |
2002年 | 59572篇 |
2001年 | 100303篇 |
2000年 | 103335篇 |
1999年 | 87815篇 |
1998年 | 25089篇 |
1997年 | 22901篇 |
1996年 | 22707篇 |
1995年 | 21941篇 |
1994年 | 20728篇 |
1993年 | 19485篇 |
1992年 | 73164篇 |
1991年 | 71052篇 |
1990年 | 69537篇 |
1989年 | 67155篇 |
1988年 | 62829篇 |
1987年 | 61838篇 |
1986年 | 58837篇 |
1985年 | 56974篇 |
1984年 | 43221篇 |
1983年 | 37177篇 |
1982年 | 22686篇 |
1981年 | 20502篇 |
1980年 | 19172篇 |
1979年 | 42231篇 |
1978年 | 29845篇 |
1977年 | 25142篇 |
1976年 | 23464篇 |
1975年 | 24992篇 |
1974年 | 30818篇 |
1973年 | 29531篇 |
1972年 | 27441篇 |
1971年 | 25852篇 |
1970年 | 23996篇 |
1969年 | 22855篇 |
1968年 | 20758篇 |
1967年 | 18931篇 |
排序方式: 共有10000条查询结果,搜索用时 390 毫秒
71.
Osric A. Forrest Daniel M. Chopyk Yael Gernez Milton R. Brown Carol K. Conrad Richard B. Moss Vin Tangpricha Limin Peng Rabindra Tirouvanziam 《Journal of cystic fibrosis》2019,18(1):64-70
Background
Resistin is an immunometabolic mediator that is elevated in several inflammatory disorders. A ligand for Toll-like receptor 4, resistin modulates the recruitment and activation of myeloid cells, notably neutrophils. Neutrophils are major drivers of cystic fibrosis (CF) lung disease, in part due to the release of human neutrophil elastase- and myeloperoxidase-rich primary granules, leading to tissue damage. Here we assessed the relationship of resistin to CF lung disease.Methods
Resistin levels were measured in plasma and sputum from three retrospective CF cohorts spanning a wide range of disease. We also assessed the ability of neutrophils to secrete resistin upon activation in vitro. Finally, we constructed a multivariate model assessing the relationship between resistin levels and lung function.Results
Plasma resistin levels were only marginally higher in CF than in healthy control subjects. By contrast, sputum resistin levels were very high in CF, reaching 50–100 fold higher levels than in plasma. Among CF patients, higher plasma resistin levels were associated with allergic bronchopulmonary aspergillosis, and higher sputum resistin levels were associated with CF-related diabetes. Mechanistically, in vitro release of neutrophil primary granules was concomitant with resistin secretion. Overall, sputum resistin levels were negatively correlated with CF lung function, independently of other variables (age, sex, and genotype).Conclusions
Our data establish relationships between resistin levels in the plasma and sputum of CF patients that correlate with disease status, and identify resistin as a novel mechanistic link between neutrophilic inflammation and lung disease in CF. 相似文献72.
73.
74.
75.
76.
77.
78.
79.
80.
Emma J. Kilford Iroise Dumontheil Nicholas W. Wood Sarah-Jayne Blakemore 《Social cognitive and affective neuroscience》2015,10(6):777-782
The catechol-O-methyltransferase (COMT) enzyme is a major determinant of prefrontal dopamine levels. The Val158Met polymorphism affects COMT enzymatic activity and has been associated with variation in executive function and affective processing. This study investigated the effect of COMT genotype on the flexible modulation of the balance between processing self-generated and processing stimulus-oriented information, in the presence or absence of affective distractors. Analyses included 124 healthy adult participants, who were also assessed on standard working memory (WM) tasks. Relative to Val carriers, Met homozygotes made fewer errors when selecting and manipulating self-generated thoughts. This effect was partly accounted for by an association between COMT genotype and visuospatial WM performance. We also observed a complex interaction between the influence of affective distractors, COMT genotype and sex on task accuracy: male, but not female, participants showed a sensitivity to the affective distractors that was dependent on COMT genotype. This was not accounted for by WM performance. This study provides novel evidence of the role of dopaminergic genetic variation on the ability to select and manipulate self-generated thoughts. The results also suggest sexually dimorphic effects of COMT genotype on the influence of affective distractors on executive function. 相似文献