全文获取类型
| 收费全文 | 3332715篇 |
| 免费 | 263955篇 |
| 国内免费 | 7206篇 |
专业分类
| 耳鼻咽喉 | 46834篇 |
| 儿科学 | 104691篇 |
| 妇产科学 | 91183篇 |
| 基础医学 | 466320篇 |
| 口腔科学 | 95258篇 |
| 临床医学 | 305687篇 |
| 内科学 | 652040篇 |
| 皮肤病学 | 71122篇 |
| 神经病学 | 281813篇 |
| 特种医学 | 130999篇 |
| 外国民族医学 | 1187篇 |
| 外科学 | 499367篇 |
| 综合类 | 79657篇 |
| 现状与发展 | 5篇 |
| 一般理论 | 1437篇 |
| 预防医学 | 270096篇 |
| 眼科学 | 78716篇 |
| 药学 | 243705篇 |
| 7篇 | |
| 中国医学 | 6716篇 |
| 肿瘤学 | 177036篇 |
出版年
| 2019年 | 26497篇 |
| 2018年 | 36806篇 |
| 2017年 | 28285篇 |
| 2016年 | 31475篇 |
| 2015年 | 35510篇 |
| 2014年 | 51116篇 |
| 2013年 | 77095篇 |
| 2012年 | 104538篇 |
| 2011年 | 110659篇 |
| 2010年 | 65241篇 |
| 2009年 | 62470篇 |
| 2008年 | 103981篇 |
| 2007年 | 110334篇 |
| 2006年 | 110957篇 |
| 2005年 | 108412篇 |
| 2004年 | 103846篇 |
| 2003年 | 99830篇 |
| 2002年 | 97277篇 |
| 2001年 | 151899篇 |
| 2000年 | 156383篇 |
| 1999年 | 132120篇 |
| 1998年 | 39818篇 |
| 1997年 | 35909篇 |
| 1996年 | 35398篇 |
| 1995年 | 33907篇 |
| 1994年 | 31546篇 |
| 1993年 | 29564篇 |
| 1992年 | 104133篇 |
| 1991年 | 100138篇 |
| 1990年 | 96356篇 |
| 1989年 | 92651篇 |
| 1988年 | 85922篇 |
| 1987年 | 84534篇 |
| 1986年 | 79655篇 |
| 1985年 | 76115篇 |
| 1984年 | 58259篇 |
| 1983年 | 49682篇 |
| 1982年 | 30701篇 |
| 1981年 | 27354篇 |
| 1979年 | 53778篇 |
| 1978年 | 38030篇 |
| 1977年 | 31961篇 |
| 1976年 | 30024篇 |
| 1975年 | 31232篇 |
| 1974年 | 38314篇 |
| 1973年 | 36607篇 |
| 1972年 | 34328篇 |
| 1971年 | 31555篇 |
| 1970年 | 29849篇 |
| 1969年 | 27744篇 |
排序方式： 共有10000条查询结果，搜索用时 15 毫秒
31.
32.
Erin L. Sutfin Jennifer Cornacchione Ross Allison J. Lazard Elizabeth Orlan Cynthia K. Suerken Kimberly D. Wiseman 《Health communication》2019,34(3):343-351
ABSTRACTAdolescents and young adults smoke waterpipe tobacco (WT) and cigarillos, at least in part, based on erroneous beliefs that these products are safer than cigarettes. To address this challenge, we used a systematic, three-phase process to develop a health communication campaign to discourage WT and cigarillo smoking among at-risk (tobacco users and susceptible non-users) 16- to 25-year-olds. In Phase 1, we used a national phone survey (N = 896) to determine salient message beliefs. Participants reported constituents (i.e., harmful chemicals) emitted by the products were worrisome. In Phase 2, we developed and evaluated four message executions, with varying imagery, tone, and unappealing products with the same constituents, using focus groups (N = 38). Participants rated one execution highly, resulting in our development of a campaign where each message: (1) identified a tobacco product and constituent in the smoke; (2) included an image of an unappealing product containing the constituent (e.g., pesticides, gasoline) to grab attention; and (3) used a humorous sarcastic tone. In Phase 3, we tested the campaign messages (17 intervention and six control) with a nationally representative online survey (N = 1,636). Participants rated intervention and control messages highly with few differences between them. Exposure to messages resulted in significant increases in all risk beliefs from pre to post (p < 0.05). For WT, intervention messages increased beliefs about addiction more than control messages (p < 0.05). This systematic, iterative approach resulted in messages that show promise for discouraging WT and cigarillo use. 相似文献
33.
K.-C. Sung D.-C. Seo S.-J. Lee M.-Y. Lee S.H. Wild C.D. Byrne 《Nutrition, metabolism, and cardiovascular diseases : NMCD》2019,29(5):489-495
Background and aims
It is not known whether non alcoholic fatty liver disease (NAFLD) is a risk factor for diabetes in non obese, non centrally-obese subjects. Our aim was to investigate relationships between fatty liver, insulin resistance and a biomarker score for liver fibrosis with incident diabetes at follow up, in subjects who were neither obese nor centrally-obese.Methods and results
As many as 70,303 subjects with a body mass index (BMI) < 25 kg/m2 and without diabetes were followed up for a maximum of 7.9 years. At baseline, fatty liver was identified by liver ultrasound, insulin resistance (IR) by homeostatic model assessment of insulin resistance (HOMA-IR) ≥2.0, and central obesity by waist circumference (waist circumference ≥90 cm (men) and ≥85 cm (women). The Fibrosis-4 (FIB-4 score) was used to estimate extent of liver fibrosis. Cox proportional hazards models adjusted for confounders were used to estimate hazard ratios (aHRs) for incident diabetes. As many as 852 incident cases of diabetes occurred during follow up (median [IQR] 3.71 [2.03] years). Mean ± SD BMI was 22.8 ± 1.8 and 21.7 ± 2.0 kg/m2 in subjects with and without diabetes at follow up. In subjects without central obesity and with fatty liver, aHRs (95% CI) for incident diabetes at follow up were 2.17 (1.56, 3.03) for men, and 2.86 (1.50,5.46) for women. Similar aHRs for incident diabetes occurred with fatty liver, IR and the highest quartile of FIB-4 combined, in men; and there was a non significant trend toward increased risk in women.Conclusions
In normal weight, non-centrally obese subjects NAFLD is an independent risk factor for incident diabetes. 相似文献34.
35.
36.
Jeroen M. van de Pol Jurjen G. Geljon Svetlana V. Belitser Geert W.J. Frederix Anke M. Hövels Marcel L. Bouvy 《Research in social & administrative pharmacy》2019,15(1):70-76
Introduction
The nature of community pharmacy is changing, shifting from the preparation and distribution of medicines to the provision of cognitive pharmaceutical services (CPS); however, often the provision of traditional services leaves little time for innovative services. This study investigated the time community pharmacists spend on the tasks and activities of daily practice and to what extent they are able to implement CPS-related services in daily practice.Methods
Self-reporting work sampling was used to register the activities of community pharmacists. A smartphone application, designed specifically for this purpose, alerted participants to register their current activity five times per working day for 6 weeks. Participants also completed an online survey about baseline characteristics.Results
Ninety-one Dutch community pharmacists provided work-sampling data (7848 registered activities). Overall, 51.5% of their time was spent on professional activities, 35.4% on semi-professional activities, and 13.1% on non-professional activities. The proportion of time devoted to CPS decreased during the workweek, whereas the time spent on traditional task increased.Discussion and conclusion
This study shows it is feasible to collect work-sampling data using smartphone technology. Community pharmacists spent almost half of their time on semi-professional and non-professional activities, activities that could be delegated to other staff members. In practice, the transition to CPS is hampered by competing traditional tasks, which prevents community pharmacists from profiling themselves as pharmaceutical experts in daily practice. 相似文献37.
38.
J. Rodríguez-Carrio A. Martínez-Zapico I. Cabezas-Rodríguez L. Benavente Á.I. Pérez-Álvarez P. López J.B. Cannata-Andía M. Naves-Díaz A. Suárez 《Nutrition, metabolism, and cardiovascular diseases : NMCD》2019,29(2):135-143
Background and aims
Since accelerated atherosclerosis has been reported in systemic lupus erythematosus (SLE), predictive biomarkers of cardiovascular disease (CVD) are needed. Among non-traditional risk factors, bone mineral density (BMD) has been related to CVD. However, its role in SLE remains controversial. This study aims to analyze the associations of subclinical atherosclerosis with traditional and non-traditional CV risk factors.Methods and results
In a cross-sectional study, atherosclerosis burden was compared between 112 female SLE patients and 31 controls. Plaque number and carotid intima-media wall thickness (cIMT) were assessed by ultrasonography. In a retrospective study, BMD determinations obtained 5-years before the ultrasonography assessment were analyzed in a subgroup of 62 patients. Plaque frequency was increased in SLE, even in patients without CV events or carotid wall thickening. cIMT was increased in patients with CVD, positively correlated with body mass index (BMI). Interestingly, a paradoxical effect of BMI on carotid parameters was observed. Whereas underweight patients (BMI < 20) showed increased prevalence of carotid plaques with low cIMT, those with BMI > 30 showed higher cIMT and plaque burden. Overweight patients (25 < BMI<30) exhibited both elevated cIMT and plaque number. BMI was an independent predictor of BMD. In our retrospective study, patients with either clinical or subclinical CVD exhibited lower BMD levels than their CV-free counterparts. A low lumbar spine BMD independently predicted CVD development after adjusting for confounders.Conclusion
SLE was associated with a higher subclinical atherosclerosis burden, a bimodal effect being observed for BMI. Decreased BMD can be a CV risk biomarker in SLE. 相似文献39.
Leonardo Jönck Staub Roberta Rodolfo Mazzali Biscaro Erikson Kaszubowski Rosemeri Maurici 《The Journal of emergency medicine》2019,56(1):53-69
Background
Lung ultrasound can accelerate the diagnosis of life-threatening diseases in adults with respiratory symptoms.Objective
Systematically review the accuracy of lung ultrasonography (LUS) for emergency diagnosis of pneumonia, acute heart failure, and exacerbation of chronic obstructive pulmonary disease (COPD)/asthma in adults.Methods
PubMed, Embase, Scopus, Web of Science, and LILACS (Literatura Latino Americana e do Caribe em Ciências da Saúde; until 2016) were searched for prospective diagnostic accuracy studies. Rutter-Gatsonis hierarchical summary receiver operating characteristic method was used to measure the overall accuracy of LUS and Reitsma bivariate model to measure the accuracy of the different sonographic signs. This review was previously registered in PROSPERO (Centre for Reviews and Dissemination, University of York, York, UK; CRD42016048085).Results
Twenty-five studies were included: 14 assessing pneumonia, 14 assessing acute heart failure, and four assessing exacerbations of COPD/asthma. The area under the summary receiver operating characteristic curve of LUS was 0.948 for pneumonia, 0.914 for acute heart failure, and 0.906 for exacerbations of COPD/asthma. In patients suspected to have pneumonia, consolidation had sensitivity of 0.82 (95% confidence interval [CI] 0.74–0.88) and specificity of 0.94 (95% CI 0.85–0.98) for this disease. In acutely dyspneic patients, modified diffuse interstitial syndrome had sensitivity of 0.90 (95% CI 0.87–0.93) and specificity of 0.93 (95% CI 0.91–0.95) for acute heart failure, whereas B-profile had sensitivity of 0.93 (95% CI 0.72–0.98) and specificity of 0.92 (95% CI 0.79–0.97) for this disease in patients with respiratory failure. In patients with acute dyspnea or respiratory failure, the A-profile without PLAPS (posterior-lateral alveolar pleural syndrome) had sensitivity of 0.78 (95% CI 0.67–0.86) and specificity of 0.94 (95% CI 0.89–0.97) for exacerbations of COPD/asthma.Conclusion
Lung ultrasound is an accurate tool for the emergency diagnosis of pneumonia, acute heart failure, and exacerbations of COPD/asthma. 相似文献40.
Christopher N. Cooley Tyler J. Beranek Matthew A. Warpinski Robert Alexander Amanda O. Esquivel 《The American journal of emergency medicine》2019,37(2):199-203