全文获取类型
收费全文 | 3005篇 |
免费 | 201篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 20篇 |
儿科学 | 109篇 |
妇产科学 | 201篇 |
基础医学 | 425篇 |
口腔科学 | 77篇 |
临床医学 | 271篇 |
内科学 | 824篇 |
皮肤病学 | 45篇 |
神经病学 | 366篇 |
特种医学 | 66篇 |
外科学 | 268篇 |
综合类 | 11篇 |
一般理论 | 2篇 |
预防医学 | 183篇 |
眼科学 | 33篇 |
药学 | 150篇 |
中国医学 | 3篇 |
肿瘤学 | 160篇 |
出版年
2023年 | 35篇 |
2022年 | 50篇 |
2021年 | 129篇 |
2020年 | 49篇 |
2019年 | 115篇 |
2018年 | 125篇 |
2017年 | 84篇 |
2016年 | 93篇 |
2015年 | 81篇 |
2014年 | 129篇 |
2013年 | 167篇 |
2012年 | 235篇 |
2011年 | 208篇 |
2010年 | 117篇 |
2009年 | 108篇 |
2008年 | 179篇 |
2007年 | 167篇 |
2006年 | 176篇 |
2005年 | 165篇 |
2004年 | 156篇 |
2003年 | 114篇 |
2002年 | 119篇 |
2001年 | 17篇 |
2000年 | 25篇 |
1999年 | 22篇 |
1998年 | 29篇 |
1997年 | 17篇 |
1996年 | 20篇 |
1995年 | 11篇 |
1994年 | 10篇 |
1993年 | 22篇 |
1992年 | 10篇 |
1991年 | 20篇 |
1990年 | 13篇 |
1989年 | 11篇 |
1988年 | 17篇 |
1987年 | 14篇 |
1986年 | 15篇 |
1985年 | 10篇 |
1983年 | 12篇 |
1981年 | 7篇 |
1979年 | 6篇 |
1978年 | 6篇 |
1975年 | 8篇 |
1974年 | 7篇 |
1973年 | 10篇 |
1971年 | 5篇 |
1970年 | 7篇 |
1969年 | 5篇 |
1967年 | 9篇 |
排序方式: 共有3214条查询结果,搜索用时 15 毫秒
71.
Ofer Beharier Romina Plitman Mayo Tal Raz Kira Nahum Sacks Letizia Schreiber Yael Suissa-Cohen Rony Chen Rachel Gomez-Tolub Eran Hadar Rinat Gabbay-Benziv Yuval Jaffe Moshkovich Tal Biron-Shental Gil Shechter-Maor Sivan Farladansky-Gershnabel Hen Yitzhak Sela Hedi Benyamini-Raischer Nitzan D. Sela Debra Goldman-Wohl Ziv Shulman Ariel Many Haim Barr Simcha Yagel Michal Neeman Michal Kovo 《The Journal of clinical investigation》2021,131(13)
BACKGROUNDThe significant risks posed to mothers and fetuses by COVID-19 in pregnancy have sparked a worldwide debate surrounding the pros and cons of antenatal SARS-CoV-2 inoculation, as we lack sufficient evidence regarding vaccine effectiveness in pregnant women and their offspring. We aimed to provide substantial evidence for the effect of the BNT162b2 mRNA vaccine versus native infection on maternal humoral, as well as transplacentally acquired fetal immune response, potentially providing newborn protection.METHODSA multicenter study where parturients presenting for delivery were recruited at 8 medical centers across Israel and assigned to 3 study groups: vaccinated (n = 86); PCR-confirmed SARS-CoV-2 infected during pregnancy (n = 65), and unvaccinated noninfected controls (n = 62). Maternal and fetal blood samples were collected from parturients prior to delivery and from the umbilical cord following delivery, respectively. Sera IgG and IgM titers were measured using the Milliplex MAP SARS-CoV-2 Antigen Panel (for S1, S2, RBD, and N).RESULTSThe BNT162b2 mRNA vaccine elicits strong maternal humoral IgG response (anti-S and RBD) that crosses the placenta barrier and approaches maternal titers in the fetus within 15 days following the first dose. Maternal to neonatal anti-COVID-19 antibodies ratio did not differ when comparing sensitization (vaccine vs. infection). IgG transfer ratio at birth was significantly lower for third-trimester as compared with second trimester infection. Lastly, fetal IgM response was detected in 5 neonates, all in the infected group.CONCLUSIONAntenatal BNT162b2 mRNA vaccination induces a robust maternal humoral response that effectively transfers to the fetus, supporting the role of vaccination during pregnancy.FUNDINGIsrael Science Foundation and the Weizmann Institute Fondazione Henry Krenter. 相似文献
72.
Tiffany Thomas Francesca Cendali Xiaoyun Fu Fabia Gamboni Evan J. Morrison Jonathan Beirne Travis Nemkov Marianna H. Antonelou Anastasios Kriebardis Ian Welsby Ariel Hay Karolina H. Dziewulska Michael P. Busch Steven Kleinman Paul W. Buehler Steven L. Spitalnik James C. Zimring Angelo D'Alessandro 《Transfusion》2021,61(6):1867-1883
73.
74.
75.
Stephanie L Mayne Knashawn H Morales Ariel A Williamson Struan F A Grant Alexander G Fiks Mathias Basner David F Dinges Babette S Zemel Jonathan A Mitchell 《Sleep》2021,44(6)
Study ObjectivesOver 75% of US high school students obtain insufficient sleep, placing them at risk for adverse health outcomes. Identification of modifiable determinants of adolescent sleep is needed to inform prevention strategies, yet little is known about the influence of the built environment on adolescent sleep.MethodsIn this prospective study, actigraphy was used to assess sleep outcomes among 110 adolescents for 14 days each in eighth and ninth grades: duration (hours/night), onset and offset, and sleeping ≥8 hours. Home addresses were linked to built environment exposures: sound levels, tree canopy cover, street density, intersection density, population density, and housing density. Mixed-effects regression estimated associations of built environment measures with sleep outcomes, adjusting for sex, race, parent education, household income, household size, grade, weeknight status, and neighborhood poverty.ResultsA 1-standard deviation (SD) increase in neighborhood sound was associated with 16 minutes later sleep onset (β = 0.28; 95% confidence interval (CI): 0.06, 0.49) and 25% lower odds of sleeping for ≥8 hours (odds ratio (OR) = 0.75, 95% CI: 0.59, 0.96). A 1-SD increase in neighborhood tree canopy was associated with 18 minutes earlier sleep onset (β = −0.31, 95% CI: −0.49, −0.13) and 10 minutes earlier sleep offset (β= −0.17, 95% CI: −0.28, −0.05). No associations were observed for density-based exposures.ConclusionsHigher neighborhood sound level was associated with lower odds of sufficient sleep, while higher tree canopy cover was associated with more favorable sleep timing. Neighborhood sound levels and tree canopy cover are potential targets for policies and interventions to support healthier sleep among adolescents. 相似文献
76.
Ariel A Williamson Nardia Zendarski Katherine Lange Jon Quach Carly Molloy Susan A Clifford Melissa Mulraney 《Sleep》2021,44(1)
Study ObjectivesTo examine longitudinal, bidirectional associations among behavioral sleep problems, internalizing and externalizing symptoms, and domains of health-related quality of life (HRQoL) from early childhood to adolescence in a population sample of Australian children.MethodData were drawn from the Longitudinal Study of Australian Children, a national prospective cohort study with 4983 children participating in the Kindergarten cohort. Data were collected when children were aged 4–5, 6–7, 8–9, 10–11, and 12–13 years. At each study wave, the primary parent (97% mothers) reported on behavioral child sleep problems, internalizing and externalizing symptoms, and HRQoL domains (psychosocial and physical). Cross-lagged structural equation models were used to evaluate bidirectional associations.ResultsAt nearly every age, behavioral sleep problems were associated with worse subsequent psychosocial and physical HRQoL. Despite bidirectional associations between mental health and HRQoL at many waves, HRQoL domains more strongly predicted later internalizing symptoms, while externalizing symptoms more strongly predicted later HRQoL. Many of the bidirectional associations among sleep, mental health, and HRQoL were found earlier in childhood.ConclusionsBehavioral sleep problems may forecast later HRQoL psychosocial and physical impairments. Attending to both sleep problems and HRQoL could prevent the progression of internalizing conditions, while a focus on externalizing concerns could prevent the worsening of these symptoms, sleep problems, and HRQoL, particularly during the transition to school. 相似文献
77.
Maya Nitecki Boris Taran Itay Ketko Gil Geva Roey Yosef Itay Toledo Gilad Twig Eva Avramovitch Barak Gordon Estela Derazne Noam Fink Ariel Furer 《Clinical microbiology and infection》2021,27(4):618-623
ObjectiveTo assess the utility of self-reported symptoms in identifying positive coronavirus disease 2019 (COVID-19) cases among predominantly healthy young adults in a military setting.MethodsA questionnaire regarding COVID-19 symptoms and exposure history was administered to all individuals contacting the Israeli Defence Forces Corona call-centre, before PCR testing. Surveyed symptoms included cough, fever, sore throat, rhinorrhoea, loss of taste or smell, chest pain and gastrointestinal symptoms. Factors were compared between positive and negative cases based on confirmatory test results, and positive likelihood ratios (LR) were calculated. Results were stratified by sex, body mass index, previous medical history and dates of questioning, and a multivariable analysis for association with positive test was conducted.ResultsOf 24 362 respondents, 59.1% were men with a median age of 20.5 years (interquartile range 19.6–22.4 years). Significant positive LRs were associated with loss of taste or smell (LR 3.38, 95% CI 3.01–3.79), suspected exposure (LR 1.33, 95% CI 1.28–1.39) and fever (LR 1.26, 95% CI 1.17–1.36). Those factors were also associated with positive PCR result in a multivariable analysis (OR 3.51, 95% CI 3.04–4.06; OR 1.86, 95% CI 1.65–2.09; and OR 1.34, 95% CI 1.19–1.51, respectively). Reports of loss of taste or smell increased gradually over time and were significantly more frequent during the late period of the study (63/5231, 1.21%; 156/7941, 1.96%; and 1505/11 190, 13.45%: p < 0.001).ConclusionLoss of taste or smell, report of a suspicious exposure and fever (>37.5°C) were consistently associated with positive LRs for a positive SARS-CoV-2 PCR test result, in a population of predominantly young and healthy adults. 相似文献
78.
David Marcelo Raviv Aviad Guttel Ariel García Reyes Valentina Simini Franco Pracca Francisco 《Journal of clinical monitoring and computing》2021,35(6):1437-1443
Journal of Clinical Monitoring and Computing - Monitoring intra-abdominal pressure (IAP) has become a standard in intensive care units. Correlation between the abdominal wall’s thickness... 相似文献
79.
80.
Mai Uchida Joseph Biederman John D. E. Gabrieli Jamie Micco Carlo de Los Angeles Ariel Brown Tara Kenworthy Elana Kagan Susan Whitfield-Gabrieli 《Social cognitive and affective neuroscience》2015,10(12):1738-1748
This study investigated the neural basis of individual variation in emotion regulation, specifically the ability to reappraise negative stimuli so as to down-regulate negative affect. Brain functions in young adults were measured with functional Magnetic Resonance Imaging during three conditions: (i) attending to neutral pictures; (ii) attending to negative pictures and (iii) reappraising negative pictures. Resting-state functional connectivity was measured with amygdala and dorsolateral prefrontal cortical (DLPFC) seed regions frequently associated with emotion regulation. Participants reported more negative affect after attending to negative than neutral pictures, and less negative affect following reappraisal. Both attending to negative vs neutral pictures and reappraising vs attending to negative pictures yielded widespread activations that were significantly right-lateralized for attending to negative pictures and left-lateralized for reappraising negative pictures. Across participants, more successful reappraisal correlated with less trait anxiety and more positive daily emotion, greater activation in medial and lateral prefrontal regions, and lesser resting-state functional connectivity between (a) right amygdala and both medial prefrontal and posterior cingulate cortices, and (b) bilateral DLPFC and posterior visual cortices. The ability to regulate emotion, a source of resilience or of risk for distress, appears to vary in relation to differences in intrinsic functional brain architecture. 相似文献