全文获取类型
收费全文 | 565篇 |
免费 | 40篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 71篇 |
妇产科学 | 7篇 |
基础医学 | 63篇 |
口腔科学 | 11篇 |
临床医学 | 80篇 |
内科学 | 142篇 |
皮肤病学 | 18篇 |
神经病学 | 27篇 |
特种医学 | 94篇 |
外科学 | 21篇 |
综合类 | 10篇 |
预防医学 | 20篇 |
眼科学 | 1篇 |
药学 | 24篇 |
中国医学 | 1篇 |
肿瘤学 | 15篇 |
出版年
2023年 | 2篇 |
2022年 | 4篇 |
2019年 | 4篇 |
2018年 | 7篇 |
2017年 | 10篇 |
2016年 | 8篇 |
2015年 | 17篇 |
2014年 | 11篇 |
2013年 | 28篇 |
2012年 | 17篇 |
2011年 | 16篇 |
2010年 | 31篇 |
2009年 | 20篇 |
2008年 | 15篇 |
2007年 | 9篇 |
2006年 | 11篇 |
2005年 | 11篇 |
2004年 | 8篇 |
2003年 | 5篇 |
2002年 | 9篇 |
2001年 | 9篇 |
2000年 | 4篇 |
1999年 | 9篇 |
1998年 | 22篇 |
1997年 | 31篇 |
1996年 | 27篇 |
1995年 | 31篇 |
1994年 | 23篇 |
1993年 | 38篇 |
1992年 | 5篇 |
1991年 | 7篇 |
1990年 | 17篇 |
1989年 | 16篇 |
1988年 | 17篇 |
1987年 | 11篇 |
1986年 | 13篇 |
1985年 | 13篇 |
1984年 | 3篇 |
1983年 | 5篇 |
1982年 | 6篇 |
1981年 | 14篇 |
1980年 | 6篇 |
1979年 | 2篇 |
1978年 | 5篇 |
1977年 | 7篇 |
1976年 | 12篇 |
1975年 | 4篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有606条查询结果,搜索用时 46 毫秒
101.
102.
103.
Colin?R?CookeEmail author Min?J?Joo Stephen?M?Anderson Todd?A?Lee Edmunds?M?Udris Eric?Johnson David?H?Au 《BMC health services research》2011,11(1):37
Background
Administrative data is often used to identify patients with chronic obstructive pulmonary disease (COPD), yet the validity of this approach is unclear. We sought to develop a predictive model utilizing administrative data to accurately identify patients with COPD. 相似文献104.
105.
Els Goetghebeur Saskia le Cessie Bianca De Stavola Erica EM Moodie Ingeborg Waernbaum “on behalf of” the topic group Causal Inference of the STRATOS initiative 《Statistics in medicine》2020,39(30):4922-4948
Although review papers on causal inference methods are now available, there is a lack of introductory overviews on what they can render and on the guiding criteria for choosing one particular method. This tutorial gives an overview in situations where an exposure of interest is set at a chosen baseline (“point exposure”) and the target outcome arises at a later time point. We first phrase relevant causal questions and make a case for being specific about the possible exposure levels involved and the populations for which the question is relevant. Using the potential outcomes framework, we describe principled definitions of causal effects and of estimation approaches classified according to whether they invoke the no unmeasured confounding assumption (including outcome regression and propensity score-based methods) or an instrumental variable with added assumptions. We mainly focus on continuous outcomes and causal average treatment effects. We discuss interpretation, challenges, and potential pitfalls and illustrate application using a “simulation learner,” that mimics the effect of various breastfeeding interventions on a child's later development. This involves a typical simulation component with generated exposure, covariate, and outcome data inspired by a randomized intervention study. The simulation learner further generates various (linked) exposure types with a set of possible values per observation unit, from which observed as well as potential outcome data are generated. It thus provides true values of several causal effects. R code for data generation and analysis is available on www.ofcaus.org , where SAS and Stata code for analysis is also provided. 相似文献
106.
107.
BACKGROUND AND PURPOSE
Conditioned gaping reactions reflect nausea-induced behaviour in rats. Cannabinoid 1 receptor (CB1) agonists interfere with the establishment of nausea-induced conditioned gaping; however, it is not known if their effects are mediated by an action at peripheral or central CB1 receptors.EXPERIMENTAL APPROACH
We utilized the conditioned gaping model of nausea to evaluate the effect of peripheral and central administration of the peripherally restricted CB1 agonist, CB13, on the establishment of LiCl-induced gaping in rats. We further evaluated the ability of HU-210 administered to the gustatory insular cortex (GIC) or visceral insular cortex (VIC) to interfere with LiCl-induced conditioned gaping and determined if this effect was mediated by CB1 receptors.KEY RESULTS
Central, but not peripheral, CB13 suppressed LiCl-induced conditioned gaping. Central administration of the potent CB1 agonist, HU-210, delivered to the VIC, but not the GIC, suppressed the establishment of LiCl-induced gaping reactions, but not LiCl-induced suppression of hedonic reactions or conditioned taste avoidance. This pattern of results suggests that HU-210 delivered to the VIC prevented LiCl-induced nausea, but not learning per se. The suppression of LiCl-induced conditioned gaping by HU-210 was mediated by CB1 receptors because it was prevented by co-administration of CB1 antagonist/inverse agonist, AM-251, into the VIC. A high dose of AM-251 (20 µg) administered alone into the VIC did not produce conditioned gaping reactions.CONCLUSIONS AND IMPLICATIONS
The nausea-relieving effects of CB1 agonists, but not the nausea-inducing effects of CB1 inverse agonists, are mediated, at least in part, by their action at the VIC in rats. 相似文献108.
GTA Jombo EM Mbaawuaga AN Gyuse MNO Enenebeaku EE Okwori EJ Peters S Akpan F Odey EA Etukumana JT Akosu 《Asian Pacific journal of tropical medicine》2010,3(5):402-406
ObjectiveTo ascertain the socio-cultural factors influencing the rate of utilization of insecticide treated bed nets (ITNs) in a malaria endemic city of Makurdi, north central Nigeria.MethodsThe study was cross-sectional in nature using systematic sampling method to identify households. Both quantitative and qualitative data was generated from adult women using structured and semi structured questionnaires, and focused group discussions (FGDs) to obtain information on rate and patterns of utilization of ITNs. Information such as age, educational level, marital status, awareness or otherwise of the existence of malaria, and factors influencing rate of ownership and utilization of ITNs were obtained. FGDs were used to obtain qualitative information on rate of utilization of ITNs not captured in the questionnaires. Data obtained was analysed using Epi Info 6 statistical software.ResultsAmong the respondents interviewed, 97.0% (2 013/2 075) were aware of existence of malaria and 87.0% of these (1 751/2 013) would associate it with mosquitoes. The rate of ownership of any bed net, ITNs and untreated bed nets (UTNs) was 25.1%, 17.0% and 8.3%, respectively. Utilization of ITNs among children was 30.0% (112/373) and UTNs 12.9% (48/373). Positive contributors to ITNs utilization were literacy, enhanced economy, experience of marriage, and being gainfully employed (P<0.05); while negative contributors were ignorance, poverty and some cultural beliefs and values.ConclusionsA more synchronized advocacy should be carried out on the potential benefits of ITNs utilization and sustained. Also ITNs should be made available to the people of the community at minimal or no cost. 相似文献
109.
Adam EM Eltorai Jack Haglin Sudheesha Perera Bielinsky A Brea Roy Ruttiman Dioscaris R Garcia Christopher T Born Alan H Daniels 《World journal of orthopedics》2016,7(6):361-369
Infections can hinder orthopedic implant function and retention.Current implant-based antimicrobial strategies largely utilize coating-based approaches in order to reduce biofilm formation and bacterial adhesion.Several emerging antimicrobial technologies that integrate a multidisciplinary combination of drug delivery systems,material science,immunology,and polymer chemistry are in development and early clinical use.This review outlines orthopedic implant antimicrobial technology,its current applications and supporting evidence,and clinically promising future directions. 相似文献
110.
DS Keller RN Tahilramani JR Flores-Gonzalez S. Ibarra EM Haas 《Surgical endoscopy》2016,30(6):2192-2198