全文获取类型
收费全文 | 2349篇 |
免费 | 206篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 37篇 |
儿科学 | 90篇 |
妇产科学 | 19篇 |
基础医学 | 232篇 |
口腔科学 | 53篇 |
临床医学 | 186篇 |
内科学 | 559篇 |
皮肤病学 | 86篇 |
神经病学 | 245篇 |
特种医学 | 200篇 |
外科学 | 410篇 |
综合类 | 34篇 |
预防医学 | 139篇 |
眼科学 | 30篇 |
药学 | 89篇 |
中国医学 | 2篇 |
肿瘤学 | 155篇 |
出版年
2021年 | 37篇 |
2019年 | 38篇 |
2018年 | 34篇 |
2017年 | 36篇 |
2016年 | 40篇 |
2015年 | 51篇 |
2014年 | 57篇 |
2013年 | 84篇 |
2012年 | 122篇 |
2011年 | 87篇 |
2010年 | 77篇 |
2009年 | 56篇 |
2008年 | 102篇 |
2007年 | 83篇 |
2006年 | 119篇 |
2005年 | 113篇 |
2004年 | 78篇 |
2003年 | 93篇 |
2002年 | 90篇 |
2001年 | 70篇 |
2000年 | 66篇 |
1999年 | 57篇 |
1998年 | 39篇 |
1997年 | 33篇 |
1996年 | 30篇 |
1995年 | 23篇 |
1994年 | 23篇 |
1993年 | 25篇 |
1992年 | 52篇 |
1991年 | 51篇 |
1990年 | 51篇 |
1989年 | 55篇 |
1988年 | 65篇 |
1987年 | 38篇 |
1986年 | 39篇 |
1985年 | 34篇 |
1984年 | 18篇 |
1983年 | 25篇 |
1982年 | 23篇 |
1981年 | 20篇 |
1979年 | 34篇 |
1978年 | 23篇 |
1977年 | 18篇 |
1976年 | 19篇 |
1974年 | 14篇 |
1973年 | 15篇 |
1971年 | 15篇 |
1970年 | 17篇 |
1967年 | 21篇 |
1966年 | 14篇 |
排序方式: 共有2566条查询结果,搜索用时 15 毫秒
1.
2.
3.
Aaron M Kipp Jennifer A Lehman Richard A Bowen Patricia E Fox Michael R Stephens Kaci Klenk Nicholas Komar Michel L Bunning 《The American journal of tropical medicine and hygiene》2006,75(4):688-690
To better understand the potential environmental health risk presented by West Nile virus (WNV)-contaminated feces, we quantified the amount of WNV present in the feces of experimentally infected American crows (Corvus brachyrhynchos) and fish crows (Corvus ossifragus). Peak fecal titers ranged from 10(3.5) to 10(8.8) plaque-forming units (PFU)/g for 10 American crows and from 10(2.3) to 10(6.4) PFU/g for 10 fish crows. The presence of infectious WNV in bird feces indicates a potential for direct transmission of WNV. Thus, handlers of sick or dead birds should take appropriate precautions to avoid exposure to fecal material. 相似文献
4.
5.
6.
Effect of acute tyrosine depletion in using a branched chain amino-acid mixture on dopamine neurotransmission in the rat brain. 总被引:1,自引:0,他引:1
Marisa Le Masurier Weite Oldenzeil Claire Lehman Philip Cowen Trevor Sharp 《Neuropsychopharmacology》2006,31(2):310-317
Central dopamine function is reduced by decreasing the availability of the catecholamine precursor, tyrosine, using a tyrosine-free amino acid mixture containing multiple large neutral as well as branched chain amino-acids, which compete with tyrosine for uptake into the brain. Current mixtures are cumbersome to make and administer, and unpalatable to patients and volunteers. Here, we investigate whether individual or limited amino-acid combinations could reduce brain tyrosine levels and hence dopamine function. Measurements of regional brain tyrosine levels, catecholamine and indoleamine synthesis (L-DOPA and 5-HTP accumulation, respectively) were used to identify an effective paradigm to test in neurochemical, behavioral and fos immunocytochemical models. Administration of leucine or isoleucine, or a mixture of leucine, isoleucine, and valine reduced tyrosine and 5-HTP, but not L-DOPA accumulation. A mixture of leucine, valine, and isoleucine supplemented with tryptophan reduced brain tyrosine and L-DOPA, but not 5-HTP. In microdialysis experiments this amino-acid mixture reduced basal and amphetamine-evoked striatal dopamine release, as well as amphetamine-induced hyperactivity. This mixture also reduced amphetamine-induced fos expression in striatal areas. In conclusion, the present study identified a small combination of amino acids that reduces brain tyrosine and dopamine function in a manner similar to mixtures of multiple amino acids. This minimal mixture may have use as a dopamine reducing paradigm in patient and volunteer studies. 相似文献
7.
8.
Shelley E Taylor Barbara J Lehman Catarina I Kiefe Teresa E Seeman 《Neuropsychopharmacology》2006,60(8):819-824
BACKGROUND: Low socioeconomic status (SES) and a harsh family environment in childhood have been linked to mental and physical health disorders in adulthood. The objective of the present investigation was to evaluate a developmental model of pathways that may help explain these links and to relate them to C-reactive protein (CRP) in the Coronary Artery Risk Development in Young Adults (CARDIA) dataset. METHODS: Participants (n = 3248) in the CARDIA study, age 32 to 47 years, completed measures of childhood SES (CSES), early family environment (risky families [RF]), adult psychosocial functioning (PsyF, a latent factor measured by depression, mastery, and positive and negative social contacts), body mass index (BMI), and C-reactive protein. RESULTS: Structural equation modeling indicated that CSES and RF are associated with C-reactive protein via their association with PsyF (standardized path coefficients: CSES to RF, RF to PsyF, PsyF to CRP, CSES to CRP, all p < .05), with good overall model fit. The association between PsyF and CRP was partially mediated by BMI (PsyF to BMI, BMI to CRP, both p < .05). CONCLUSIONS: Low childhood SES and a harsh early family environment appear to be related to elevated C-reactive protein in adulthood through pathways involving psychosocial dysfunction and high body mass index. 相似文献
9.
10.