全文获取类型
收费全文 | 5362篇 |
免费 | 313篇 |
国内免费 | 20篇 |
专业分类
耳鼻咽喉 | 32篇 |
儿科学 | 176篇 |
妇产科学 | 112篇 |
基础医学 | 686篇 |
口腔科学 | 94篇 |
临床医学 | 473篇 |
内科学 | 1023篇 |
皮肤病学 | 136篇 |
神经病学 | 480篇 |
特种医学 | 122篇 |
外科学 | 658篇 |
综合类 | 23篇 |
一般理论 | 4篇 |
预防医学 | 664篇 |
眼科学 | 132篇 |
药学 | 331篇 |
中国医学 | 8篇 |
肿瘤学 | 541篇 |
出版年
2023年 | 48篇 |
2022年 | 101篇 |
2021年 | 194篇 |
2020年 | 128篇 |
2019年 | 170篇 |
2018年 | 189篇 |
2017年 | 128篇 |
2016年 | 149篇 |
2015年 | 151篇 |
2014年 | 227篇 |
2013年 | 285篇 |
2012年 | 412篇 |
2011年 | 429篇 |
2010年 | 275篇 |
2009年 | 237篇 |
2008年 | 321篇 |
2007年 | 345篇 |
2006年 | 322篇 |
2005年 | 280篇 |
2004年 | 258篇 |
2003年 | 262篇 |
2002年 | 193篇 |
2001年 | 52篇 |
2000年 | 46篇 |
1999年 | 31篇 |
1998年 | 57篇 |
1997年 | 41篇 |
1996年 | 26篇 |
1995年 | 24篇 |
1994年 | 20篇 |
1993年 | 25篇 |
1992年 | 23篇 |
1991年 | 24篇 |
1990年 | 27篇 |
1989年 | 21篇 |
1988年 | 21篇 |
1987年 | 20篇 |
1986年 | 10篇 |
1985年 | 21篇 |
1984年 | 9篇 |
1983年 | 9篇 |
1982年 | 17篇 |
1981年 | 10篇 |
1980年 | 5篇 |
1978年 | 7篇 |
1977年 | 5篇 |
1976年 | 7篇 |
1974年 | 7篇 |
1973年 | 3篇 |
1972年 | 3篇 |
排序方式: 共有5695条查询结果,搜索用时 15 毫秒
991.
Crowe FL Key TJ Appleby PN Travis RC Overvad K Jakobsen MU Johnsen NF Tjønneland A Linseisen J Rohrmann S Boeing H Pischon T Trichopoulou A Lagiou P Trichopoulos D Sacerdote C Palli D Tumino R Krogh V Bueno-de-Mesquita HB Kiemeney LA Chirlaque MD Ardanaz E Sánchez MJ Larrañaga N González CA Quirós JR Manjer J Wirfält E Stattin P Hallmans G Khaw KT Bingham S Ferrari P Slimani N Jenab M Riboli E 《The American journal of clinical nutrition》2008,87(5):1405-1413
992.
The study aimed ar apprehending the social representations of the health users in case of hospital infection. Exploratory research with 28 health and law professionals and of a public hospital of Teresina-PI. The data were produced through the interviews and processed by the software Alceste 4.8. The hierarchical descendent analysis showed 4 classes of words that sized up a conflict between the proposals of the program of infection control and the practicing of health professionals, seeing that negligencing the psychological aspects and direct the focus of the attention to economical, biological and epidemiological aspects, with much attention to the rights that the health users have to be waited on the hospitals without running risk of acquiring a hospital infection. 相似文献
993.
994.
995.
Garcia-Marcos L Valverde-Molina J Ortega ML Sanchez-Solis M Martinez-Torres AE Castro-Rodríguez JA 《Maternal & child nutrition》2008,4(4):304-310
None of the epidemiological studies indicating that obesity is a risk factor for asthma in schoolchildren have used the percent body fat (PBF) to define obesity. The present study compares the definition of obesity using body mass index (BMI), PBF and the raw sum of the thickness of four skinfolds (SFT) to evaluate this condition as a risk factor for asthma. All classes of children of the target ages of 6-8 years of all schools in four municipalities of Murcia (Spain) were surveyed. Participation rate was 70.2% and the number of children included in the study was 931. Height, weight and SFT (biceps, triceps, subscapular and suprailiac) were measured according to standard procedures. Current active asthma was defined from several questions of the International Study of Asthma and Allergies in Childhood questionnaire. Obesity was defined using two standard cut-off points for BMI and PBF, and the 85th percentile for BMI, PBF and SFT. The highest quartile of each type of measurement was also compared with the lowest. A multiple logistic regression analysis was made for the various obesity definitions, adjusting for age, asthma in the mother and father and gender. The adjusted odds ratios of having asthma among obese children were different for boys and girls and varied across the different obesity definitions. For the standard cut-off points of BMI they were 1.19 [95% confidence interval (CI) 0.41-3.43] for girls and 2.00 (95% CI 0.97-4.10) for boys; however, for PBF (boys 25%, girls 30%) the corresponding figures were 1.54 (95% CI 0.63-3.73) and 1.20 (95% CI 0.66-2.21). BMI, PBF and SFT showed more consistency between each other when using the other cut-off points. BMI, PBF (except standard cut-off points) and SFT produce relatively comparable results when analysing the interaction between obesity and asthma. 相似文献
996.
Lutsey PL Diez Roux AV Jacobs DR Burke GL Harman J Shea S Folsom AR 《American journal of public health》2008,98(11):1963-1970
Objectives. We assessed whether markers of acculturation
(birthplace and number of US generations) and socioeconomic status (SES) are
associated with markers of subclinical cardiovascular disease—carotid
artery plaque, internal carotid intima-media thickness, and
albuminuria—in 4 racial/ethnic groups.Methods. With data from the Multi-Ethnic Study of
Atherosclerosis (n = 6716 participants aged 45–84 years)
and race-specific binomial regression models, we computed prevalence ratios
adjusted for demographics and traditional cardiovascular risk factors.Results. The adjusted US- to foreign-born prevalence ratio for
carotid plaque was 1.20 (99% confidence interval [CI] = 0.97, 1.39)
among Whites, 1.91 (99% CI = 0.94, 2.94) among Chinese, 1.62 (99% CI
= 1.28, 2.06) among Blacks, and 1.23 (99% CI = 1.15, 1.31)
among Hispanics. Greater carotid plaque prevalence was found among Whites,
Blacks, and Hispanics with a greater number of generations with US residence
(P < .001) and among Whites with less education and
among Blacks with lower incomes. Similar associations were observed with
intima-media thickness. There was also evidence of an inverse association
between albuminuria and SES among Whites and Hispanics.Conclusions. Greater US acculturation and lower SES were
associated with a higher prevalence of carotid plaque and greater intima-media
thickness but not with albuminuria. Maintenance of healthful habits among recent
immigrants should be encouraged.Beginning with the Ni-Hon-San study,1,2 which was initiated in the 1960s,
research has associated increased acculturation to Western lifestyles with more-adverse
cardiovascular disease (CVD) risk factor profiles and with increased CVD morbidity and
mortality. Specifically, greater Western acculturation has frequently been linked to
increased body mass index (BMI; weight in kilograms divided by height in meters
squared),3–5 waist circumference and abdominal
obesity,6,7 hypertension,7–9 type II
diabetes,10,11 and CVD morbidity and mortality.1,12,13 However, little
research has explored associations between acculturation and subclinical CVD.14,15Abundant research also exists that links low socioeconomic status (SES) to increased
levels of CVD risk factors, morbidity, and mortality.14,16–18 In
general, SES has been found to be inversely related to subclinical measures of CVD,
including coronary artery calcification (CAC),14,19–22 carotid artery plaque, and
intima-media thickness20,23–26 and albuminuria.27 Relations with peripheral artery disease have been inconsistent.28–30 The extent to which these associations vary by
race/ethnicity has been examined infrequently. There is, however, some evidence that the
relation between SES and disease may differ across racial/ethnic groups.14,31,32 Specifically, in
the Multi-Ethnic Study of Atherosclerosis (MESA) there was a higher prevalence of CAC
among Whites with low education than among those with more education, whereas the
reverse was true for Hispanics.14We investigated whether acculturation and SES were associated with other measures of
subclinical disease, specifically with carotid plaque and albuminuria. The relation of
acculturation and SES to CAC has been described in MESA.14 Although CAC, carotid plaque, and albuminuria are all subclinical measures of CVD
and are related to adverse clinical outcomes, these measures represent different aspects
of the disease process and have relatively weak intercorrelations.33 Thus, they may be differentially related to our exposures of interest.The investigation of these patterns is important from a public health perspective and may
yield clues regarding the etiology of atherosclerosis. On the basis of previous work,14 we hypothesized that increased Western acculturation, as assessed by place of
birth, migration history, and duration of US residence, is associated with increased
carotid plaque, intima-media thickness, and albuminuria. Additionally, we expected there
to be an interaction between race/ethnicity and SES with respect to their associations
with subclinical CVD. Specifically, we expected Whites and Blacks at lower SES to have
more-adverse subclinical CVD profiles than those at higher SES, whereas for Hispanics
and Chinese, we expected the reverse to be true. 相似文献
997.
BACKGROUND: Triclosan is a synthetic chemical with broad antimicrobial activity that has been used extensively in consumer products, including personal care products, textiles, and plastic kitchenware. OBJECTIVES: This study was designed to assess exposure to triclosan in a representative sample > or = 6 years of age of the U.S. general population from the 2003-2004 National Health and Nutrition Examination Survey (NHANES). METHODS: We analyzed 2,517 urine samples using automated solid-phase extraction coupled to isotope dilution-high-performance liquid chromatography-tandem mass spectrometry. RESULTS: We detected concentrations of total (free plus conjugated) triclosan in 74.6% of samples at concentrations of 2.4-3,790 microg/L. The geometric mean and 95th percentile concentrations were 13.0 microg/L (12.7 microg/g creatinine) and 459.0 microg/L (363.8 mug/g creatinine), respectively. We observed a curvilinear relation between age and adjusted least square geometric mean (LSGM) concentrations of triclosan. LSGM concentrations of triclosan were higher in people in the high household income than in people in low (p < 0.01) and medium (p = 0.04) income categories. CONCLUSIONS: In about three-quarters of urine samples analyzed as part of NHANES 2003-2004, we detected concentrations of triclosan. Concentrations differed by age and socioeconomic status but not by race/ethnicity and sex. Specifically, the concentrations of triclosan appeared to be highest during the third decade of life and among people with the highest household incomes. 相似文献
998.
Gazetta CE Santos Mde L Vendramini SH Poletti NA Pinto Neto JM Villa TC 《Revista latino-americana de enfermagem》2008,16(2):306-313
This study aims to review plans for tuberculosis control through the analysis of measures for tuberculosis contact tracing in Brazil from 1984 to 2004. This article presents a literature review on tuberculosis control published in manuals of the Ministry of Health and the State Department of Health of Sao Paulo, and in Medline and Lilacs databases. There was a gap in the standardization of control measures in the decade from 1984 to 1994. It was concluded that health professionals need to incorporate TB control and prevention actions from the perspective of health surveillance and systematic monitoring. 相似文献
999.
1000.
Duell EJ Travier N Lujan-Barroso L Boutron-Ruault MC Clavel-Chapelon F Palli D Krogh V Mattiello A Tumino R Sacerdote C Rodriguez L Sanchez-Cantalejo E Navarro C Barricarte A Dorronsoro M Khaw KT Wareham N Allen NE Tsilidis KK Bueno-de-Mesquita HB Jeurnink SM Numans ME Peeters PH Lagiou P Valanou E Trichopoulou A Kaaks R Lukanova-McGregor A Bergman MM Boeing H Manjer J Lindkvist B Stenling R Hallmans G Dahm CC Overvad K Olsen A Tjonneland A Bakken K Lund E Jenab M McCormack V Rinaldi S 《American journal of epidemiology》2010,172(12):1384-1393
The worldwide incidence of gastric adenocarcinoma (GC) is lower in women than in men. Furthermore, cancer patients treated with estrogens have been reported to have a lower subsequent risk of GC. The authors conducted a prospective analysis of menstrual and reproductive factors, exogenous hormone use, and GC in 335,216 women from the European Prospective Investigation Into Cancer and Nutrition, a cohort study of individuals aged 35-70 years from 10 European countries. After a mean follow-up of 8.7 years (through 2004), 181 women for whom complete exposure data were available developed GC. Adjusted hazard ratios and 95% confidence intervals were estimated using Cox proportional hazards models. All statistical tests were 2-sided. Women who had ovariectomy had a 79% increased risk of GC (based on 25 cases) compared with women who did not (hazard ratio = 1.79, 95% confidence interval: 1.15, 2.78). Total cumulative years of menstrual cycling was inversely associated with GC risk (fifth vs. first quintile: hazard ratio = 0.55, 95% confidence interval: 0.31, 0.98; P(trend) = 0.06). No other reproductive factors analyzed were associated with risk of GC. The results of this analysis provide some support for the hypothesis that endogenous ovarian sex hormones lower GC incidence in women. 相似文献