收费全文 | 917篇 |
免费 | 64篇 |
国内免费 | 5篇 |
耳鼻咽喉 | 10篇 |
儿科学 | 45篇 |
妇产科学 | 14篇 |
基础医学 | 106篇 |
口腔科学 | 64篇 |
临床医学 | 142篇 |
内科学 | 162篇 |
皮肤病学 | 36篇 |
神经病学 | 42篇 |
特种医学 | 128篇 |
外科学 | 45篇 |
综合类 | 29篇 |
预防医学 | 85篇 |
眼科学 | 6篇 |
药学 | 26篇 |
1篇 | |
肿瘤学 | 45篇 |
2023年 | 6篇 |
2021年 | 5篇 |
2019年 | 12篇 |
2018年 | 11篇 |
2017年 | 8篇 |
2016年 | 14篇 |
2015年 | 16篇 |
2014年 | 17篇 |
2013年 | 28篇 |
2012年 | 17篇 |
2011年 | 22篇 |
2010年 | 29篇 |
2009年 | 32篇 |
2008年 | 21篇 |
2007年 | 39篇 |
2006年 | 29篇 |
2005年 | 31篇 |
2004年 | 26篇 |
2003年 | 20篇 |
2002年 | 27篇 |
2001年 | 24篇 |
2000年 | 25篇 |
1999年 | 18篇 |
1998年 | 46篇 |
1997年 | 51篇 |
1996年 | 42篇 |
1995年 | 22篇 |
1994年 | 34篇 |
1993年 | 27篇 |
1992年 | 14篇 |
1991年 | 13篇 |
1990年 | 16篇 |
1989年 | 31篇 |
1988年 | 27篇 |
1987年 | 17篇 |
1986年 | 14篇 |
1985年 | 11篇 |
1984年 | 15篇 |
1983年 | 16篇 |
1982年 | 15篇 |
1981年 | 11篇 |
1980年 | 9篇 |
1979年 | 5篇 |
1978年 | 6篇 |
1977年 | 5篇 |
1976年 | 7篇 |
1973年 | 5篇 |
1972年 | 6篇 |
1970年 | 8篇 |
1968年 | 6篇 |
Aims: To report one large company's surveillance and compare its findings with those of a standard cross-sectional survey in the same workforce.
Methods: A supermarket company with 324 in-store bakeries producing bread from raw ingredients conducted a three-stage health surveillance programme in around 3000 bakery employees. The first stage involved the administration of a simple respiratory questionnaire. If chest symptoms were present a second questionnaire focusing on their work relationship was administered. If positive a blood sample was requested for the measurement of specific IgE to flour and fungal α-amylase. The results were compared to an independent cross-sectional survey of employees in 20 of the company's stores.
Results: Two hundred and ninety nine (92%) of the company's bakeries took part in surveillance. The overall employee response for the first stage was 77%; a quarter of those with respiratory symptoms reported that they were work related. Seventy four (61%) of those with work related chest symptoms had a measurement of specific IgE to either flour or fungal α-amylase, of whom 30 (41%) had a positive result. Surveillance estimated that 1% of bakery employees (1% bakers, 2% managers, 0.6% confectioners) had work related symptoms with specific IgE. This compared with 4% (7.5% bakers, 3.3% managers, 0% confectioners) in the cross-sectional survey (n = 166, 93% response).
Conclusion: Comparison with a standard cross-sectional survey suggests that routine surveillance can underestimate the workplace burden of disease. The reasons may include technical or resource issues and uncertainties over confidentiality or the perceived consequences of participation. More research needs to be done looking into the design and efficacy of surveillance in occupational asthma.
相似文献Material and Methods: Genomic DNA was obtained from 252 adults who were part of a prospective longitudinal study on the progression of periodontal disease in a general adult Australian population. Single nucleotide polymorphisms at positions −592 and −1082 in the interleukin-10 promoter were analysed using an induced heteroduplex methodology and used to determine interleukin-10 promoter haplotypes in individual samples. Periodontitis progression was assessed by measuring probing depths and relative attachment levels at regular intervals over a 5-year period. A generalized linear model was used to analyse the data, with age, gender, smoking status, interleukin-1 genotype and Porphyromonas gingivalis included as possible confounders.
Results: There was a significant ( p ≈ 0.02) main effect of interleukin-10 haplotypes, with individuals having either the ATA/ACC or the ACC/ACC genotype experiencing around 20% fewer probing depths of ≥ 4 mm compared to individuals with other genotypes. Age and smoking had significant ( p < 0.001) additional effects.
Conclusion: These data suggest that the interleukin-10 genotype contributes to the progression of periodontal disease. 相似文献