全文获取类型
收费全文 | 13818篇 |
免费 | 1024篇 |
国内免费 | 39篇 |
专业分类
耳鼻咽喉 | 77篇 |
儿科学 | 356篇 |
妇产科学 | 171篇 |
基础医学 | 1812篇 |
口腔科学 | 273篇 |
临床医学 | 1451篇 |
内科学 | 2702篇 |
皮肤病学 | 133篇 |
神经病学 | 1367篇 |
特种医学 | 561篇 |
外科学 | 1884篇 |
综合类 | 137篇 |
一般理论 | 32篇 |
预防医学 | 1677篇 |
眼科学 | 240篇 |
药学 | 975篇 |
中国医学 | 20篇 |
肿瘤学 | 1013篇 |
出版年
2024年 | 11篇 |
2023年 | 138篇 |
2022年 | 212篇 |
2021年 | 475篇 |
2020年 | 289篇 |
2019年 | 397篇 |
2018年 | 446篇 |
2017年 | 352篇 |
2016年 | 376篇 |
2015年 | 442篇 |
2014年 | 546篇 |
2013年 | 751篇 |
2012年 | 1153篇 |
2011年 | 1128篇 |
2010年 | 698篇 |
2009年 | 577篇 |
2008年 | 985篇 |
2007年 | 935篇 |
2006年 | 893篇 |
2005年 | 873篇 |
2004年 | 807篇 |
2003年 | 737篇 |
2002年 | 607篇 |
2001年 | 115篇 |
2000年 | 70篇 |
1999年 | 79篇 |
1998年 | 117篇 |
1997年 | 90篇 |
1996年 | 79篇 |
1995年 | 58篇 |
1994年 | 58篇 |
1993年 | 48篇 |
1992年 | 40篇 |
1991年 | 28篇 |
1990年 | 24篇 |
1989年 | 21篇 |
1988年 | 19篇 |
1987年 | 16篇 |
1986年 | 15篇 |
1985年 | 15篇 |
1984年 | 22篇 |
1983年 | 14篇 |
1982年 | 20篇 |
1981年 | 16篇 |
1980年 | 12篇 |
1979年 | 14篇 |
1978年 | 14篇 |
1977年 | 9篇 |
1976年 | 6篇 |
1973年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
Paul M Dietze Damien J Jolley Tanya N Chikritzhs Susan Clemens Paul Catalano Tim Stockwell 《BMC public health》2009,9(1):70
Background
There is little research on the relationship between key socioeconomic variables and alcohol related harms in Australia. The aim of this research was to examine the relationship between income inequality and the rates of alcohol-attributable hospitalisation and death at a local-area level in Australia. 相似文献992.
Miguel A Sanjoaquin Babak Choodari-Oskooei Catherine Dolbear Venkata Putcha Ashu Sehgal Tim J Key Henrik M?ller 《European journal of cancer prevention》2007,16(1):10-16
We report incidence, mortality and survival from colorectal cancer in South-east England using data from 162,022 incident cases and 97,697 deaths collected between 1972 and 2001 at the Thames Cancer Registry, which currently covers 14 million people. Overall, there was an increase in the incidence of colorectal cancer among men aged 50 years and over, and a decrease among the youngest age groups. In women, there was a clear decrease in incidence among those aged less than 60 years but a slight increase among those aged 60-79 years. Furthermore, there has been a steady decrease in mortality for all ages, larger in women than in men, and an increase in the 10-year relative survival for both sexes from just over 30% among those followed-up during 1981-1986 to just over 45% among those followed-up during 1997-2001. 相似文献
993.
Carolyn Tarrant Andrew M Colman Tim Stokes 《The British journal of general practice》2008,58(556):780-783
Recent changes to the organisation and delivery of primary care in the UK have the potential to reduce continuity of care markedly, but it is not clear how this will have an impact on patient trust. This study aims to test the associations between specific aspects of continuity in the GP–patient relationship, and patient trust, informed by the theoretical framework of behavioural game theory. A cross-sectional survey of patients in three Leicestershire general practices was conducted. Regression analysis showed that ratings of the GP''s interpersonal care, past experience of cooperation, and expectation of continuing care from the GP were all independent predictors of patient trust. These findings highlight the value of longitudinal aspects of the GP–patient relationship. 相似文献
994.
995.
996.
997.
998.
999.
Tim Takken Raoul Engelbert Monique van Bergen Jaap Groothoff Jeroen Nauta Koen van Hoeck Marc Lilien Paul Helders 《Pediatric nephrology (Berlin, Germany)》2009,24(11):2217-2223
The six-minute walking test (6MWT) may be a practical test for the evaluation functional exercise capacity in children with
end-stage renal disease (ESRD). The aim of this study was to investigate the 6MWT performance in children with ESRD compared
to reference values obtained in healthy children and, secondly, to study the relationship between 6MWT performance with anthropometric
variables, clinical parameters, aerobic capacity and muscle strength. Twenty patients (13 boys and seven girls; mean age 14.1 ± 3.4 years)
on dialysis participated in this study. Anthropometrics were taken in a standardized manner. The 6MWT was performed in a 20-m-long
track in a straight hallway. Aerobic fitness was measured using a cycle ergometer test to determine peak oxygen uptake
( \textV· \textO\text2peak ) \left( {\mathop {\text{V}}\limits^\cdot {{\text{O}}_{\text{2peak}}}} \right) , peak rate (Wpeak) and ventilatory threshold (VT). Muscle strength was measured using hand-held myometry. Children with ESRD showed a reduced
6MWT performance (83% of predicted, p < 0.0001), irrespective of the reference values used. The strongest predictors of 6MWT performance were haematocrit and height.
Regression models explained 59% (haematocrit and height) to 60% (haematocrit) of the variance in 6MWT performance. 6MWT performance
was not associated with
\textV· \textO\text2peak {\mathop {\text{V}}\limits^\cdot {{\text{O}}_{\text{2peak}}}} , strength, or other anthropometric variables, but it was significantly associated with haematocrit and height. Children with
ESRD scored lower on the 6MWT than healthy children. Based on these results, the 6MWT may be a useful instrument for monitoring
clinical status in children with ESRD, however it cannot substitute for other fitness tests, such as a progressive exercise
test to measure
\textV· \textO\text2peak {\mathop {\text{V}}\limits^\cdot {{\text{O}}_{\text{2peak}}}} or muscle strength tests. 相似文献
1000.
Natasha L. Larke Helen A. Weiss Philippe Mayaud Philippe Van de Perre Tim Clayton Abdoulaye Ouedraogo Nicolas Nagot 《Tropical medicine & international health : TM & IH》2009,14(3):267-275
Objective HIV-1 genital viral loads have not been extensively used as markers of HIV transmissibility. We set out to determine whether the variability of genital HIV-1 RNA over time necessitates design adjustments in studies measuring genital shedding to account for this variability.
Methods We used data from a completed trial of HSV suppressive therapy to estimate the correlation of plasma and genital HIV-1 RNA quantities sampled at different times. These correlation estimates were used to estimate the relative sample sizes needed to detect an impact on HIV-1 genital and plasma quantities assuming a variable number of pre- and post-randomisation repeated measurements. The treatment effect on quantities of genital and plasma HIV-1 RNA were analysed using random effects linear regression.
Results Post-randomisation plasma HIV-1 RNA was highly correlated within-women, while genital HIV-1 RNA was less strongly correlated. Related to this, the sample size required to detect a treatment effect on genital HIV-1 RNA decreased with increasing numbers of post-randomisation measurements up to 6–7 measurements, but varied less for plasma HIV-1 RNA. In contrast, repeated pre-randomisation measurements of plasma HIV-1 RNA increased study power more than genital HIV-1 RNA because of the high correlation of plasma HIV-1 RNA measurements between the pre- and post-randomisation samples. Re-analysis of the trial data illustrated the increased precision of the treatment effect on genital HIV-1 with increasing post-randomisation measurements.
Conclusions Designs allowing for repeated post-randomisation measures should be used to increase the precision in estimates of genital HIV-1 RNA. Repeated post-randomisation measurements of plasma HIV-1 RNA are of limited benefit. 相似文献
Methods We used data from a completed trial of HSV suppressive therapy to estimate the correlation of plasma and genital HIV-1 RNA quantities sampled at different times. These correlation estimates were used to estimate the relative sample sizes needed to detect an impact on HIV-1 genital and plasma quantities assuming a variable number of pre- and post-randomisation repeated measurements. The treatment effect on quantities of genital and plasma HIV-1 RNA were analysed using random effects linear regression.
Results Post-randomisation plasma HIV-1 RNA was highly correlated within-women, while genital HIV-1 RNA was less strongly correlated. Related to this, the sample size required to detect a treatment effect on genital HIV-1 RNA decreased with increasing numbers of post-randomisation measurements up to 6–7 measurements, but varied less for plasma HIV-1 RNA. In contrast, repeated pre-randomisation measurements of plasma HIV-1 RNA increased study power more than genital HIV-1 RNA because of the high correlation of plasma HIV-1 RNA measurements between the pre- and post-randomisation samples. Re-analysis of the trial data illustrated the increased precision of the treatment effect on genital HIV-1 with increasing post-randomisation measurements.
Conclusions Designs allowing for repeated post-randomisation measures should be used to increase the precision in estimates of genital HIV-1 RNA. Repeated post-randomisation measurements of plasma HIV-1 RNA are of limited benefit. 相似文献