全文获取类型
收费全文 | 11525篇 |
免费 | 735篇 |
国内免费 | 33篇 |
专业分类
耳鼻咽喉 | 90篇 |
儿科学 | 366篇 |
妇产科学 | 340篇 |
基础医学 | 1606篇 |
口腔科学 | 354篇 |
临床医学 | 1731篇 |
内科学 | 1965篇 |
皮肤病学 | 168篇 |
神经病学 | 1057篇 |
特种医学 | 225篇 |
外科学 | 1043篇 |
综合类 | 113篇 |
一般理论 | 10篇 |
预防医学 | 1630篇 |
眼科学 | 153篇 |
药学 | 716篇 |
1篇 | |
中国医学 | 27篇 |
肿瘤学 | 698篇 |
出版年
2023年 | 71篇 |
2022年 | 131篇 |
2021年 | 267篇 |
2020年 | 194篇 |
2019年 | 263篇 |
2018年 | 332篇 |
2017年 | 223篇 |
2016年 | 288篇 |
2015年 | 304篇 |
2014年 | 436篇 |
2013年 | 596篇 |
2012年 | 912篇 |
2011年 | 960篇 |
2010年 | 540篇 |
2009年 | 494篇 |
2008年 | 828篇 |
2007年 | 837篇 |
2006年 | 790篇 |
2005年 | 730篇 |
2004年 | 684篇 |
2003年 | 568篇 |
2002年 | 585篇 |
2001年 | 94篇 |
2000年 | 67篇 |
1999年 | 94篇 |
1998年 | 109篇 |
1997年 | 91篇 |
1996年 | 64篇 |
1995年 | 67篇 |
1994年 | 50篇 |
1993年 | 55篇 |
1992年 | 51篇 |
1991年 | 30篇 |
1990年 | 32篇 |
1989年 | 31篇 |
1988年 | 38篇 |
1987年 | 32篇 |
1986年 | 21篇 |
1985年 | 36篇 |
1984年 | 32篇 |
1983年 | 32篇 |
1982年 | 22篇 |
1981年 | 31篇 |
1980年 | 26篇 |
1979年 | 23篇 |
1978年 | 15篇 |
1977年 | 12篇 |
1974年 | 11篇 |
1973年 | 10篇 |
1972年 | 11篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Alexandre Pereira Aparecida S. Pietro Pereira C��lio Lopes Silva Gutemberg de Melo Rocha Ivo Lebrun Osvaldo A. Sant'Anna Denise V. Tambourgi 《The American journal of tropical medicine and hygiene》2010,82(4):678-682
Bordetella pertussis is a gram-negative bacillus that causes the highly contagious disease known as pertussis or whooping cough. Antibody response in children may vary depending on the vaccination schedule and the product used. In this study, we have analyzed the antibody response of cellular pertussis vaccinated children against B. pertussis strains and their virulence factors, such as pertussis toxin, pertactin, and filamentous hemagglutinin. After the completion of the immunization process, according to the Brazilian vaccination program, children serum samples were collected at different periods of time, and tested for the presence of specific antibodies and antigenic cross-reactivity. Results obtained show that children immunized with three doses of the Brazilian whole-cell pertussis vaccine present high levels of serum antibodies capable of recognizing the majority of the components present in vaccinal and non-vaccinal B. pertussis strains and their virulence factors for at least 2 years after the completion of the immunization procedure. 相似文献
992.
993.
994.
995.
Seasonality of cryptosporidiosis: A meta-analysis approach 总被引:1,自引:0,他引:1
Objectives
We developed methodology for and conducted a meta-analysis to examine how seasonal patterns of cryptosporidiosis, a primarily waterborne diarrheal illness, relate to precipitation and temperature fluctuations worldwide.Methods
Monthly cryptosporidiosis data were abstracted from 61 published epidemiological studies that cover various climate regions based on the Köppen Climate Classification. Outcome data were supplemented with monthly aggregated ambient temperature and precipitation for each study location. We applied a linear mixed-effect model to relate the monthly normalized cryptosporidiosis incidence with normalized location-specific temperature and precipitation data. We also conducted a sub-analysis of associations between the Normalized Difference Vegetation Index (NDVI), a remote sensing measure for the combined effect of temperature and precipitation on vegetation, and cryptosporidiosis in Sub-Saharan Africa.Results
Overall, and after adjusting for distance from the equator, increases in temperature and precipitation predict an increase in cryptosporidiosis; the strengths of relationship vary by climate subcategory. In moist tropical locations, precipitation is a strong seasonal driver for cryptosporidiosis whereas temperature is in mid-latitude and temperate climates. When assessing lagged relationships, temperature and precipitation remain strong predictors. In Sub-Saharan Africa, after adjusting for distance from the equator, low NDVI values are predictive of an increase in cryptosporidiosis in the following month.Discussion
In this study we propose novel methodology to assess relationships between disease outcomes and meteorological data on a global scale. Our findings demonstrate that while climatic conditions typically define a pathogen habitat area, meteorological factors affect timing and intensity of seasonal outbreaks. Therefore, meteorological forecasts can be utilized to develop focused prevention programs for waterborne cryptosporidiosis. 相似文献996.
997.
This study investigates population mobility and its relationship with area level deprivation and health. Based on UK movement in the year preceding the 2001 census, small areas in Scotland were classified as being one of the following population types; decreasing, increasing or stable (with high or low turnover). In the most deprived areas, illness rates for those under 65 were significantly lower in stable populations with low turnover than in other areas of comparable deprivation. Decreasing populations in deprived areas had significantly highest illness rates overall. Leaving those in poor health behind may lead to artifactual increases in area based health inequalities. 相似文献
998.
Sylvie Noiseux Denise St-Cyr Tribble Claude Leclerc Nicole Ricard Ellen Corin Raymond Morissette Roseline Lambert 《BMC health services research》2009,9(1):1-12
Background
Vast quantities of electronic data are collected about patients and service users as they pass through health service and other public sector organisations, and these data present enormous potential for research and policy evaluation. The Health Information Research Unit (HIRU) aims to realise the potential of electronically-held, person-based, routinely-collected data to conduct and support health-related studies. However, there are considerable challenges that must be addressed before such data can be used for these purposes, to ensure compliance with the legislation and guidelines generally known as Information Governance.Methods
A set of objectives was identified to address the challenges and establish the Secure Anonymised Information Linkage (SAIL) system in accordance with Information Governance. These were to: 1) ensure data transportation is secure; 2) operate a reliable record matching technique to enable accurate record linkage across datasets; 3) anonymise and encrypt the data to prevent re-identification of individuals; 4) apply measures to address disclosure risk in data views created for researchers; 5) ensure data access is controlled and authorised; 6) establish methods for scrutinising proposals for data utilisation and approving output; and 7) gain external verification of compliance with Information Governance.Results
The SAIL databank has been established and it operates on a DB2 platform (Data Warehouse Edition on AIX) running on an IBM 'P' series Supercomputer: Blue-C. The findings of an independent internal audit were favourable and concluded that the systems in place provide adequate assurance of compliance with Information Governance. This expanding databank already holds over 500 million anonymised and encrypted individual-level records from a range of sources relevant to health and well-being. This includes national datasets covering the whole of Wales (approximately 3 million population) and local provider-level datasets, with further growth in progress. The utility of the databank is demonstrated by increasing engagement in high quality research studies.Conclusion
Through the pragmatic approach that has been adopted, we have been able to address the key challenges in establishing a national databank of anonymised person-based records, so that the data are available for research and evaluation whilst meeting the requirements of Information Governance. 相似文献999.
Denise?W?Pallett Emily?Soh Mary-Lou?Edwards Kathleen?Bodey Laurie?CK?Lau J?Ian?Cooper Peter?H?Howarth Andrew?F?Walls Hui?Wang 《Environmental health : a global access science source》2009,8(Z1):S10
Background
Wild plants harbour a variety of viruses and these have the potential to alter the composition of pollen. The potential consequences of virus infection of grasses on pollen-induced allergic disease are not known.Methods
We have collected pollen from Dactylis glomerata (cocksfoot; a grass species implicated as a trigger of allergic rhino-conjunctivitis) from Wytham Wood, Oxfordshire UK. Extracts were prepared from pollen from uninfected grass, and from grass naturally infected by the Cocksfoot streak potyvirus (CSV). Preparations of pollen from virus-infected and non-infected grasses were employed in skin testing 15 grass pollen-allergic subjects with hayfever. Allergen profiles of extracts were investigated by Western blotting for IgE with sera from allergic subjects.Results
The prevalence of CSV infection in cocksfoot grasses sampled from the study site varied significantly over an eight-year period, but infection rates of up to 70% were detected. Virus infection was associated with small alterations in the quantities of pollen proteins detected by polyacrylamide gel electrophoresis, and in the patterns of allergens identified by Western blotting with IgE from grass pollen allergic subjects. For individual subjects there were differences in potencies of standardised extracts of pollen from virus-free and virus-infected plants as assessed by skin testing, though a consistent pattern was not established for the group of 15 subjects.Conclusion
Infection rates for CSV in cocksfoot grass can be high, though variable. Virus-induced alterations in components of grass pollen have the potential to alter the allergenic potency.1000.
Denise A Castronovo Kenneth KH Chui Elena N Naumova 《Environmental health : a global access science source》2009,8(1):61