全文获取类型
收费全文 | 3394283篇 |
免费 | 252939篇 |
国内免费 | 5041篇 |
专业分类
耳鼻咽喉 | 47239篇 |
儿科学 | 111389篇 |
妇产科学 | 94068篇 |
基础医学 | 493177篇 |
口腔科学 | 97083篇 |
临床医学 | 306805篇 |
内科学 | 651102篇 |
皮肤病学 | 74216篇 |
神经病学 | 271020篇 |
特种医学 | 129477篇 |
外国民族医学 | 902篇 |
外科学 | 510058篇 |
综合类 | 76598篇 |
现状与发展 | 13篇 |
一般理论 | 1314篇 |
预防医学 | 268221篇 |
眼科学 | 79587篇 |
药学 | 254168篇 |
13篇 | |
中国医学 | 6360篇 |
肿瘤学 | 179453篇 |
出版年
2018年 | 35910篇 |
2017年 | 27353篇 |
2016年 | 30648篇 |
2015年 | 34841篇 |
2014年 | 48947篇 |
2013年 | 74198篇 |
2012年 | 101493篇 |
2011年 | 107771篇 |
2010年 | 63981篇 |
2009年 | 60702篇 |
2008年 | 101749篇 |
2007年 | 108185篇 |
2006年 | 109363篇 |
2005年 | 106438篇 |
2004年 | 102930篇 |
2003年 | 98625篇 |
2002年 | 96235篇 |
2001年 | 151421篇 |
2000年 | 156212篇 |
1999年 | 132080篇 |
1998年 | 38484篇 |
1997年 | 34082篇 |
1996年 | 34047篇 |
1995年 | 32591篇 |
1994年 | 30265篇 |
1993年 | 28591篇 |
1992年 | 105694篇 |
1991年 | 103354篇 |
1990年 | 100924篇 |
1989年 | 97549篇 |
1988年 | 90323篇 |
1987年 | 88717篇 |
1986年 | 83851篇 |
1985年 | 80788篇 |
1984年 | 60627篇 |
1983年 | 51962篇 |
1982年 | 30868篇 |
1981年 | 27835篇 |
1979年 | 56924篇 |
1978年 | 40326篇 |
1977年 | 33834篇 |
1976年 | 32247篇 |
1975年 | 34471篇 |
1974年 | 41707篇 |
1973年 | 39892篇 |
1972年 | 37221篇 |
1971年 | 35149篇 |
1970年 | 32402篇 |
1969年 | 30796篇 |
1968年 | 28148篇 |
排序方式: 共有10000条查询结果,搜索用时 17 毫秒
121.
Elizabeth C Frenzel Georgia A Thomas Hend A Hanna 《Infection control and hospital epidemiology》2006,27(5):512-514
At the time of hire, 4059 of 6522 healthcare workers required a 2-step tuberculin skin test; 114 workers (2.8%) demonstrated a boosted reaction after the second step. Boosted reactions were significantly associated with male sex and older age. A verbal history of previous tuberculin skin test results was not a reliable indicator of baseline tuberculin skin test status at the time of hire. 相似文献
122.
Allison J. Cowin PhD ; Nicholas Hatzirodos BSc ; Justin Rigden PhD ; Robert Fitridge FRACS ; David A. Belford PhD 《Wound repair and regeneration》2006,14(4):421-426
High levels of tumor necrosis factor-alpha (TNF-alpha), a pro-inflammatory cytokine, are present in the wound fluid of chronic nonhealing wounds. This leads to increased inflammation, cytokine expression, and ultimately results in impaired wound healing and tissue destruction. Etanercept is a recombinant fusion protein that consists of the soluble TNF receptor (p75) linked to the Fc portion of human IgG1. It is an effective inhibitor of TNF-alpha and has been shown to provide rapid and sustained improvement in rheumatoid arthritis by acting as a soluble receptor binding TNF-alpha and preventing its proinflammatory activities. Therefore, the aim of this study was to determine whether Etanercept could inhibit TNF-alpha activity in chronic wound fluid. Wound fluid was collected from the venous leg ulcers of 16 different patients. The effect of Etanercept on TNF-alpha activity was evaluated using both a TNF-alpha bioassay and an enzyme-linked immunoassay. Etanercept was found to reduce the cytotoxic effect of chronic wound fluid on L929 fibroblasts by approximately 30% and neutralized TNF-alpha binding in the enzyme-linked immunoassay by up to 80%. Direct application of Etanercept to chronic wounds may therefore reduce the inflammatory activity of TNF-alpha, which could reduce the chronicity of venous leg ulcers and thus aid in the healing of these wounds. 相似文献
123.
124.
Pankaj Dabir Snehal Dabir B V Siva Prasad M V R Reddy 《Infection, genetics and evolution》2006,6(4):287-291
Molecular characterization of Wuchereria bancrofti is essential to develop suitable anti-filarial drugs and vaccines. We describe here isolation, sequence analysis and cloning of a partial cDNA of an enzyme superoxide dismutase from this parasite. The immunoscreening of a lambda zap W. bancrofti microfilarial (Mf) cDNA library with microfilaremic sera had resulted in the isolation of several seroreactive clones including, WbSOD. This clone contained a 309 bp insert and showed significant nucleotide and deduced amino acid sequence homologies to the superoxide dismutases of other nematode parasites. The antioxidant property of this enzyme may have important contribution in the defense mechanism of the parasite against host immune response. 相似文献
125.
Steven M Shechter Andrew J Schaefer R Scott Braithwaite Mark S Roberts 《Medical decision making》2006,26(5):550-553
The authors discuss techniques for Monte Carlo (MC) cohort simulations that reduce the number of simulation replications required to achieve a given degree of precision for various output measures. Known as variance reduction techniques, they are often used in industrial engineering and operations research models, but they are seldom used in medical models. However, most MC cohort simulations are well suited to the implementation of these techniques. The authors discuss the cost of implementation versus the benefit of reduced replications. 相似文献
126.
Michiel R. de Boer Jos Twisk Annette C. Moll Hennie J. M. Völker-Dieben Henrica C. W. de Vet Ger H. M. B. van Rens 《Ophthalmic & physiological optics》2006,26(6):535-544
Consecutive patients (n = 215) who were referred to optometric (55%) or multidisciplinary (45%) low-vision services and above 50 years of age were recruited from four hospitals in the Netherlands. They completed two vision-related quality of life questionnaires, the Vision Quality of Life Core Measure (VCM1) and the Low Vision Quality of Life Questionnaire (LVQOL), before their first visit with low-vision services and 1 year later. At follow-up, patients referred to multidisciplinary low-vision services had lower scores on the mobility subscale of the LVQOL than patients referred to optometric low-vision services [5.3 points; 95% confidence interval (CI): 0.2-10.5]. Paired sample t-tests for the two groups of patients taken together show improvement for the VCM1 (3.1 points; 95% CI: 0.6-5.6) and deterioration for the basic aspects of vision (3.5 points; 95% CI: 1.1-5.9) and the mobility (6.6 points; 95% CI: 3.7-9.5) subscales of the LVQOL. In conclusion, people referred to optometric services showed less deterioration in mobility than those referred to multidisciplinary services. No differences were observed for any of the other subscales of the LVQOL and the VCM1. Future research in this field should include randomized controlled designs comparing low-vision services with no treatment or placebo. 相似文献
127.
128.
B Nkgudi K A Robertson J Volmink B M Mayosi 《Suid-Afrikaanse tydskrif vir geneeskunde》2006,96(3):206-208
OBJECTIVE: To determine whether under-reporting of rheumatic fever occurs at hospital, municipal, provincial and national levels of the South African health system. BACKGROUND: Information on the incidence of rheumatic fever (RF) and the prevalence of rheumatic heart disease (RHD) is required for the prevention of valvular heart disease in developing countries. In South Africa, RF was made a notifiable condition in 1989. It has recently been suggested that the reporting of RF cases may be incomplete, possibly because of underreporting by health care professionals and deficient administration of the disease notification system in South Africa. METHOD AND RESULTS: We assessed whether underreporting of RF cases occurs by comparing the numbers of RF cases reported per year at hospital, municipal, provincial and national levels from 1990 to 2004. There was a fall in the number of RF cases reported per year at national and provincial level over the 15 years of observation. A detailed analysis of the number of RF cases reported at hospital, municipal and provincial level for a 5-year period showed that more cases were diagnosed in one hospital (serving a smaller population) than were captured at municipal and provincial level (serving a larger population), suggesting underreporting by health care professionals. There were discrepancies in the number of cases reported at municipal, provincial and national level, suggesting poor administration of the notification system. CONCLUSION: There appears to be underreporting of RF cases by health care professionals, and poor administration of the RF notification system. Health care professionals need to be educated about the statutory requirement to notify all RF cases in South Africa. An effective national disease notification system is required. 相似文献
129.
Claire M Rickard Brigit L Roberts Jonathon Foote Matthew R McGrail 《Dimensions of critical care nursing》2006,25(5):234-242
Research coordinators in intensive care are a growing specialty about which little is known. This cross-sectional study surveyed the Australia and New Zealand Intensive Care Research Coordinators' Group (n = 49) regarding demographics, education, employment history, job structure, and role content. Most research coordinators were highly qualified and experienced nurses who undertake pharmaceutical trials, multicenter projects, departmental medical and nursing research, audits and data registries, and their own projects. 相似文献
130.