全文获取类型
收费全文 | 3771篇 |
免费 | 189篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 74篇 |
儿科学 | 173篇 |
妇产科学 | 69篇 |
基础医学 | 379篇 |
口腔科学 | 58篇 |
临床医学 | 311篇 |
内科学 | 703篇 |
皮肤病学 | 9篇 |
神经病学 | 1017篇 |
特种医学 | 16篇 |
外科学 | 111篇 |
综合类 | 116篇 |
预防医学 | 661篇 |
眼科学 | 4篇 |
药学 | 130篇 |
1篇 | |
中国医学 | 124篇 |
肿瘤学 | 26篇 |
出版年
2023年 | 55篇 |
2022年 | 151篇 |
2021年 | 200篇 |
2020年 | 146篇 |
2019年 | 185篇 |
2018年 | 161篇 |
2017年 | 153篇 |
2016年 | 168篇 |
2015年 | 117篇 |
2014年 | 242篇 |
2013年 | 268篇 |
2012年 | 223篇 |
2011年 | 277篇 |
2010年 | 183篇 |
2009年 | 169篇 |
2008年 | 192篇 |
2007年 | 149篇 |
2006年 | 119篇 |
2005年 | 157篇 |
2004年 | 146篇 |
2003年 | 63篇 |
2002年 | 70篇 |
2001年 | 34篇 |
2000年 | 19篇 |
1999年 | 19篇 |
1998年 | 23篇 |
1997年 | 14篇 |
1996年 | 13篇 |
1995年 | 14篇 |
1994年 | 13篇 |
1993年 | 10篇 |
1992年 | 9篇 |
1991年 | 9篇 |
1990年 | 8篇 |
1988年 | 6篇 |
1986年 | 9篇 |
1985年 | 12篇 |
1984年 | 23篇 |
1983年 | 12篇 |
1982年 | 16篇 |
1981年 | 10篇 |
1980年 | 16篇 |
1979年 | 18篇 |
1978年 | 9篇 |
1977年 | 7篇 |
1976年 | 12篇 |
1975年 | 11篇 |
1974年 | 10篇 |
1973年 | 12篇 |
1972年 | 8篇 |
排序方式: 共有3982条查询结果,搜索用时 15 毫秒
1.
《Journal of the Academy of Nutrition and Dietetics》2022,122(11):2060-2071
BackgroundVoices for Food was a longitudinal community, food pantry–based intervention informed by the social ecological model, and designed to improve food security, dietary intake, and quality among clients, which was carried out in 24 rural food pantries across 6 Midwestern states.ObjectiveOur objective was to evaluate changes in adult food security, dietary intake, and quality from baseline (2014) to follow-up (2016), and to assess the role of adult food security on dietary outcomes.DesignA multistate, longitudinal, quasi-experimental intervention with matched treatment and comparison design was used to evaluate treatment vs comparison group changes over time and changes in both groups over time.Participants/settingAdult food pantry clients (n = 617) completed a demographic food security survey, and up to three 24-hour dietary recalls at baseline (n = 590) and follow-up (n = 160).InterventionCommunity coaching served as the experimental component, which only “treatment” communities received, and a food council guide and food pantry toolkit were provided to both “treatment” and matched “comparison” communities.Main outcome measuresChange in adult food security status, mean usual intakes of nutrients and food groups, and Healthy Eating Index-2010 scores were the main outcome measures.Statistical analyses performedLinear mixed models estimated changes in outcomes by intervention group and by adult food security status over time.ResultsImprovements in adult food security score (–0.7 ± 0.3; P = .01), Healthy Eating Index-2010 total score (4.2 ± 1.1; P < .0001), and empty calories component score (3.4 ± 0.5; P <.0001) from baseline to follow-up were observed in treatment and comparison groups, but no statistically significant changes were found for adult food security status, dietary quality, and usual intakes of nutrients and food groups between the 2 groups over time. The intervention effect on dietary quality and usual intake changes over time by adult food security status were also not observed.ConclusionsFood pantry clients in treatment and comparison groups had higher food security and dietary quality at the follow-up evaluation of the Voices for Food intervention trial compared with baseline, despite the lack of difference among the groups as a result of the experimental coaching component. 相似文献
2.
3.
4.
《Neuropsychopharmacology》2019,85(11):956-965
BackgroundBinge eating and other forms of disordered eating behavior (DEB) are associated with failed inhibitory control. This study investigated the neural correlates of failed inhibitory control as a potential biomarker for DEB.MethodsThe study used prospective longitudinal data from the European IMAGEN study adolescent cohort. Participants completed baseline assessments (questionnaires and a brain scan [functional magnetic resonance imaging]) at 14 years of age and a follow-up assessment (questionnaires) at 16 years of age. Self-reported binge eating and/or purging were used to indicate presence of DEB. Neural correlates of failed inhibition were assessed using the stop signal task. Participants were categorized as healthy control subjects (reported no DEB at both time points), maintainers (reported DEB at both time points), recoverers (reported DEB at baseline only), and developers (reported DEB at follow-up only). Forty-three individuals per group with complete scanning data were matched on gender, age, puberty, and intelligence (N = 172).ResultsAt baseline, despite similar task performance, incorrectly responding to stop signals (failed inhibitory control) was associated with greater recruitment of the medial prefrontal cortex and anterior cingulate cortex in the developers compared with healthy control subjects and recoverers.ConclusionsGreater recruitment of the medial prefrontal and anterior cingulate regions during failed inhibition accords with abnormal evaluation of errors contributing to DEB development. As this precedes symptom onset and is evident despite normal task performance, neural responses during failed inhibition may be a useful biomarker of vulnerability for DEB. This study highlights the potential value of prospective neuroimaging studies for identifying markers of illness before the emergence of behavior changes. 相似文献
5.
6.
《Clinical neurophysiology》2019,130(9):1562-1569
ObjectiveConventional deep brain stimulation (DBS) systems with ring-shaped leads generate spherical electrical fields. In contrast, novel directional leads use segmented electrodes. Aim of this study was to quantify the impedance variations over time in subjects with the directional Cartesia-Boston® system.MethodsImpedance records, programming settings, and clinical data of 11 consecutive Parkinsonian patients implanted with DBS directional leads in two Italian centers (Udine and Vicenza) were retrospectively evaluated. Data were collected before starting stimulation (in the operating room and at days 5 and 40) and after switching stimulation on at the successive follow-up visits (1, 6 and 12 months).ResultsDirectional leads have significantly higher impedance than ring leads. Stimulated contacts had always lower impedance compared to non-stimulated contacts. Before DBS-on, all contacts had higher impedance in the operating room, with an initial decrease five days post-surgery and a subsequent increase at day 40, more evident for directional contacts. The impedance of directional leads increased post-implantation at 1 and 6 months with a plateau at 12 months.ConclusionsThere was a significant difference between the directional and ring leads at baseline (before activation of DBS) and during follow-up (chronic DBS).SignificanceOur study reveals new information about the impedance of segmented electrodes that is useful for patient management during the initial test period, as well as during long-term DBS follow-up. 相似文献
7.
8.
Su Jeong Seong Jin Pyo Hong Bong-Jin Hahm Hong Jin Jeon Jee Hoon Sohn Jun Young Lee Maeng Je Cho 《Journal of Korean medical science》2015,30(11):1675-1681
While decreasing trend in gender differences in alcohol use disorders was reported in Western countries, the change in Asian countries is unknown. This study aims to explore the shifts in gender difference in alcohol abuse (AA) and dependence (AD) in Korea. We compared the data from two nation-wide community surveys to evaluate gender differences in lifetime AA and AD by Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV). Face-to-face interviews using the Composite International Diagnostic Interview (CIDI) were applied to all subjects in 2001 (n=6,220) and 2011 (n=6,022). Male-to-female ratio of odds was decreased from 6.41 (95% CI, 4.81-8.54) to 4.37 (95% CI, 3.35-5.71) for AA and from 3.75 (95% CI, 2.96-4.75) to 2.40 (95% CI, 1.80-3.19) for AD. Among those aged 18-29, gender gap even became statistically insignificant for AA (OR, 1.59; 95% CI, 0.97-2.63) and AD (OR, 1.18; 95% CI, 0.80-2.41) in 2011. Men generally showed decreased odds for AD (0.55; 95% CI, 0.45-0.67) and women aged 30-39 showed increased odds for AA (2.13; 95% CI 1.18-3.84) in 2011 compared to 2001. Decreased AD in men and increased AA in women seem to contribute to the decrease of gender gap. Increased risk for AA in young women suggests needs for interventions. 相似文献
9.
Kimberly B. Glazer Kendrin R. Sonneville Nadia Micali Sonja A. Swanson Ross Crosby Nicholas J. Horton Kamryn T. Eddy Alison E. Field 《The Journal of adolescent health》2019,64(2):165-171
Purpose
To quantify eating disorder (ED) stability and diagnostic transition among a community-based sample of adolescents and young adult females in the United States.Methods
Using 11 prospective assessments from 9,031 U.S. females ages 9–15 years at baseline of the Growing Up Today Study, we classified cases of the following EDs involving bingeing and purging: bulimia nervosa (BN), binge ED, purging disorder (PD), and subthreshold variants defined by less frequent (monthly vs. weekly) bingeing and purging behaviors. We measured number of years symptomatic and probability of maintaining symptoms, crossing to another diagnosis, or resolving symptoms across consecutive surveys.Results
Study lifetime disorder prevalence was 2.1% for BN and roughly 6% each for binge ED and PD. Most cases reported symptoms during only one survey year. Twenty-six percent of cases crossed between diagnoses during follow-up. Among participants meeting full threshold diagnostic criteria, transition from BN was most prevalent, crossing most frequently from BN to PD (12.9% of BN cases). Within each disorder phenotype, 20%–40% of cases moved between subthreshold and full threshold criteria across consecutive surveys.Conclusions
Diagnostic crossover is not rare among adolescent and young adult females with an ED. Transition patterns from BN to PD add support for considering these classifications in the same diagnostic category of disorders that involve purging. The prevalence of crossover between monthly and weekly symptom frequency suggests that a continuum or staging approach may increase utility of ED classification for prognostic and therapeutic intervention. 相似文献10.
Charlotte J. Harden Bernard M. Corfe J. Craig Richardson Peter W. Dettmar Jenny R. Paxman 《Nutrition Research》2009
This cross-sectional analysis evaluated the effect of age and body mass index (BMI) on Three-Factor Eating Questionnaire scores in males. Subjects (n = 60) were recruited according to BMI status. Each completed the 51-item Three-Factor Eating Questionnaire. The group was split at the median age to produce a “younger” and “older” group for statistical analysis. A 2-way between-groups analysis of variance revealed a significant main effect of BMI on disinhibition (P = .003) and hunger (P = .041) with higher levels found in overweight males compared to healthy-weight counterparts. A significant main effect of age on hunger (P = .046) demonstrated older males were less susceptible to hunger than younger males. These insights provide a better understanding of eating behavior across the male life cycle and may assist health professionals to better guide men in weight management in the light of rising overweight/obesity. 相似文献