全文获取类型
收费全文 | 1004篇 |
免费 | 155篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 41篇 |
妇产科学 | 82篇 |
基础医学 | 190篇 |
口腔科学 | 58篇 |
临床医学 | 99篇 |
内科学 | 159篇 |
皮肤病学 | 22篇 |
神经病学 | 44篇 |
特种医学 | 52篇 |
外科学 | 160篇 |
综合类 | 35篇 |
一般理论 | 1篇 |
预防医学 | 77篇 |
眼科学 | 12篇 |
药学 | 55篇 |
中国医学 | 2篇 |
肿瘤学 | 63篇 |
出版年
2021年 | 9篇 |
2019年 | 6篇 |
2018年 | 16篇 |
2017年 | 13篇 |
2016年 | 15篇 |
2015年 | 22篇 |
2014年 | 27篇 |
2013年 | 29篇 |
2012年 | 51篇 |
2011年 | 53篇 |
2010年 | 36篇 |
2009年 | 21篇 |
2008年 | 35篇 |
2007年 | 59篇 |
2006年 | 47篇 |
2005年 | 50篇 |
2004年 | 34篇 |
2003年 | 50篇 |
2002年 | 29篇 |
2001年 | 34篇 |
2000年 | 33篇 |
1999年 | 21篇 |
1998年 | 24篇 |
1997年 | 20篇 |
1996年 | 10篇 |
1995年 | 19篇 |
1994年 | 17篇 |
1993年 | 24篇 |
1992年 | 22篇 |
1991年 | 16篇 |
1990年 | 19篇 |
1989年 | 28篇 |
1988年 | 31篇 |
1987年 | 29篇 |
1986年 | 17篇 |
1985年 | 18篇 |
1984年 | 11篇 |
1983年 | 14篇 |
1982年 | 18篇 |
1981年 | 14篇 |
1980年 | 6篇 |
1979年 | 16篇 |
1978年 | 17篇 |
1976年 | 5篇 |
1975年 | 7篇 |
1974年 | 8篇 |
1973年 | 7篇 |
1972年 | 6篇 |
1969年 | 6篇 |
1968年 | 5篇 |
排序方式: 共有1159条查询结果,搜索用时 0 毫秒
21.
22.
23.
24.
25.
Layla Banihashemi Christine W. Peng Timothy Verstynen Meredith L. Wallace Daniel N. Lamont Hussain M. Alkhars FangCheng Yeh Joseph E. Beeney Howard J. Aizenstein Anne Germain 《Human brain mapping》2021,42(8):2445
While stress may be a potential mechanism by which childhood threat and deprivation influence mental health, few studies have considered specific stress‐related white matter pathways, such as the stria terminalis (ST) and medial forebrain bundle (MFB). Our goal was to examine the relationships between childhood adversity and ST and MFB structural integrity and whether these pathways may provide a link between childhood adversity and affective symptoms and disorders. Participants were young adults (n = 100) with a full distribution of maltreatment history and affective symptom severity. Threat was determined by measures of childhood abuse and repeated traumatic events. Socioeconomic deprivation (SED) was determined by a measure of childhood socioeconomic status (parental education). Participants underwent diffusion spectrum imaging. Human Connectome Project data was used to perform ST and MFB tractography; these tracts were used as ROIs to extract generalized fractional anisotropy (gFA) from each participant. Childhood threat was associated with ST gFA, such that greater threat was associated with less ST gFA. SED was also associated with ST gFA, however, conversely to threat, greater SED was associated with greater ST gFA. Additionally, threat was negatively associated with MFB gFA, and MFB gFA was negatively associated with post‐traumatic stress symptoms. Our results suggest that childhood threat and deprivation have opposing influences on ST structural integrity, providing new evidence that the context of childhood adversity may have an important influence on its neurobiological effects, even on the same structure. Further, the MFB may provide a novel link between childhood threat and affective symptoms. 相似文献
26.
27.
28.
29.
30.
D.W. Reid R. Latham I.L. Lamont M. Camara L.F. Roddam 《Journal of cystic fibrosis》2013,12(6):688-699
BackgroundIntravenous antibiotics for pulmonary exacerbations (PEs) of cystic fibrosis (CF) usually target Pseudomonas aeruginosa. Insights into the CF lung microbiome have questioned this approach. We used RT-qPCR to determine whether intravenous antibiotics reduced P. aeruginosa numbers and whether this correlated with improved lung function. We also investigated antibiotic effects on other common respiratory pathogens in CF.MethodsSputa were collected from patients when stable and again during a PE. Sputa were expectorated into a RNA preservation buffer for RNA extraction and preparation of cDNA. qPCR was used to enumerate viable P. aeruginosa as well as Streptococcus pneumoniae, Haemophilus influenzae, Staphylococcus aureus, Burkholderia cepacia complex and Aspergillus fumigatus.ResultsFifteen CF patients were followed through 21 PEs. A complete set of serial sputum samples was unavailable for two patients (three separate PEs). P. aeruginosa numbers did not increase immediately prior to a PE, but numbers during intravenous antibiotic treatment were reduced ≥ 4-log in 6/18 and ≥ 1-log in 4/18 PEs. In 7/18 PEs, P. aeruginosa numbers changed very little with intravenous antibiotics and one patient demonstrated a ≥ 2-log increase in P. aeruginosa load. H. influenzae and S. pneumoniae were detected in ten and five PEs respectively, but with antibiotic treatment these bacteria rapidly became undetectable in 6/10 and 4/5 PEs, respectively. There was a negative correlation between P. aeruginosa numbers and FEV1 during stable phase (rs = 0.75, p < 0.05), and reductions in P. aeruginosa load with intravenous antibiotic treatment correlated with improved FEV1 (rs = 0.52, p < 0.05).ConclusionsExacerbations are not due to increased P. aeruginosa numbers in CF adults. However, lung function improvements correlate with reduced P. aeruginosa burden suggesting that current antibiotic treatment strategies remain appropriate in most patients. Improved understanding of PE characterised by unchanged P. aeruginosa numbers and minimal lung function improvement following treatment may allow better targeted therapies. 相似文献