全文获取类型
收费全文 | 81316篇 |
免费 | 5487篇 |
国内免费 | 2237篇 |
专业分类
耳鼻咽喉 | 1071篇 |
儿科学 | 5304篇 |
妇产科学 | 741篇 |
基础医学 | 8725篇 |
口腔科学 | 1271篇 |
临床医学 | 6178篇 |
内科学 | 10411篇 |
皮肤病学 | 1109篇 |
神经病学 | 7446篇 |
特种医学 | 1632篇 |
外国民族医学 | 5篇 |
外科学 | 6965篇 |
综合类 | 9715篇 |
现状与发展 | 2篇 |
预防医学 | 7518篇 |
眼科学 | 957篇 |
药学 | 12719篇 |
31篇 | |
中国医学 | 2467篇 |
肿瘤学 | 4773篇 |
出版年
2024年 | 186篇 |
2023年 | 1435篇 |
2022年 | 2807篇 |
2021年 | 3406篇 |
2020年 | 2662篇 |
2019年 | 3032篇 |
2018年 | 2835篇 |
2017年 | 2655篇 |
2016年 | 2581篇 |
2015年 | 2612篇 |
2014年 | 4944篇 |
2013年 | 5162篇 |
2012年 | 4555篇 |
2011年 | 5178篇 |
2010年 | 4140篇 |
2009年 | 4057篇 |
2008年 | 4107篇 |
2007年 | 4021篇 |
2006年 | 3450篇 |
2005年 | 2907篇 |
2004年 | 2546篇 |
2003年 | 2158篇 |
2002年 | 1660篇 |
2001年 | 1434篇 |
2000年 | 1366篇 |
1999年 | 1089篇 |
1998年 | 1050篇 |
1997年 | 931篇 |
1996年 | 788篇 |
1995年 | 709篇 |
1994年 | 661篇 |
1993年 | 586篇 |
1992年 | 545篇 |
1991年 | 477篇 |
1990年 | 445篇 |
1989年 | 412篇 |
1988年 | 335篇 |
1987年 | 309篇 |
1986年 | 293篇 |
1985年 | 564篇 |
1984年 | 647篇 |
1983年 | 411篇 |
1982年 | 490篇 |
1981年 | 426篇 |
1980年 | 380篇 |
1979年 | 351篇 |
1978年 | 305篇 |
1977年 | 207篇 |
1976年 | 202篇 |
1975年 | 152篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
《Health & place》2022
PurposeAccording to the social determinants of health framework, income inequality is a potential risk factor for adverse mental health. However, few studies have explored the mechanisms suspected to mediate this relationship. The current study addresses this gap through a mediation analysis to determine if social support and community engagement act as mediators linking neighbourhood income inequality to maternal anxiety and depressive symptoms within a cohort of new mothers living in the City of Calgary, Canada.MethodsData collected at three years postpartum from mothers belonging to the All Our Families (AOF) cohort were used in the current study. Maternal data were collected between 2012 and 2015 and linked to neighbourhood socioeconomic data from the 2006 Canadian Census. Income inequality was measured using Gini coefficients derived from 2006 after-tax census data. Generalized structural equation models were used to quantify the associations between income inequality and mental health symptoms, and to assess the potential direct and indirect mediating effects of maternal social support and community engagement.ResultsIncome inequality was not significantly associated with higher depressive symptoms (β = 0.32, 95%CI = −0.067, 0.70), anxiety symptoms (β = 0.11, 95%CI = −0.39, 0.60), or lower social support. Income inequality was not associated with community engagement. For the depression models, higher social support was significantly associated with lower depressive symptoms (β = −0.13, 95%CI = −0.15, −0.097), while community engagement was not significantly associated with depressive symptoms (β = 0.059, 95%CI = −0.15, 0.27). Similarly, for the anxiety models, lower anxiety symptoms were significantly associated with higher levels of social support (β = −0.17, 95%CI = −0.20, −0.13) but not with higher levels of community engagement (β = 0.14, 95%CI = −0.14, 0.41).ConclusionThe current study did not find clear evidence for social support or community engagement mediating the relationship between neighbourhood income inequality and maternal mental health. Future investigations should employ a broader longitudinal approach to capture changes in income inequality, potential mediators, and mental health symptomatology over time. 相似文献
2.
Clinical characteristics of pediatric patients with COVID-19 between Omicron era vs. pre-Omicron era
《Journal of infection and chemotherapy》2022,28(11):1501-1505
IntroductionDetailed data on clinical characteristics in children with the omicron strain of SARS-COV-2 are limited.MethodsWe conducted a retrospective observational study of children with COVID-19 at the National Center for Child Health and Development to evaluate the clinical manifestations during and before the emergence of the omicron variant. Only symptomatic patients without underlying diseases were included. Participants were divided into two temporal groups: the “omicron era” (1/2022–2/2022) and the “pre-omicron era,” where the delta variant predominated (7/2021–11/2021). The patients were subclassified into an older vaccine-eligible group (aged 12–17 years), a younger vaccine-eligible group (aged 5–11 years), and a vaccine-ineligible group (aged 0–4 years).ResultsWe compared 113 patients in the omicron era with 106 in the pre-omicron era. Most patients in both eras had non-severe disease, and no patients required mechanical ventilation or died. Among patients aged 0–4 years, sore throat and hoarseness were more common during the omicron era than the pre-omicron era (11.1% vs. 0.0% and 11.1% vs. 1.5%, respectively). Croup syndrome was diagnosed in all patients with hoarseness. Among patients aged 5–11 years, vomiting was more frequent during the omicron era (47.2%) than during the pre-omicron era (21.7%). Cough and rhinorrhea were less common during the omicron era in patients aged 0–4 and 5–11 years, respectively, than during the pre-omicron era.ConclusionsIn children with COVID-19, clinical manifestations differed between the omicron and pre-omicron eras. In the Omicron era, croup syndrome was more frequent in vaccine-ineligible children. 相似文献
3.
Dongbing Lai Emma C. Johnson Sarah Colbert Gayathri Pandey Grace Chan Lance Bauer Meredith W. Francis Victor Hesselbrock Chella Kamarajan John Kramer Weipeng Kuang Sally Kuo Samuel Kuperman Yunlong Liu Vivia McCutcheon Zhiping Pang Martin H. Plawecki Marc Schuckit Jay Tischfield Leah Wetherill Yong Zang Howard J. Edenberg Bernice Porjesz Arpana Agrawal Tatiana Foroud 《Alcoholism, clinical and experimental research》2022,46(3):374-383
4.
5.
6.
7.
《Research in social & administrative pharmacy》2022,18(9):3694-3698
In this paper, we argue that understanding and addressing the problem of poor-quality medical products requires a more interdisciplinary approach than has been evident to date. While prospective studies based on rigorous standardized methodologies are the gold standard for measuring the prevalence of poor-quality medical products and understanding their distribution nationally and internationally, they should be complemented by social science research to unpack the complex set of social, economic, and governance factors that underlie these patterns. In the following sections, we discuss specific examples of prospective quality surveys and of social science studies, highlighting the value of cross-sector partnerships in driving high-quality, policy-relevant research in this area. 相似文献
8.
《Pancreatology》2022,22(8):1175-1180
BackgroundHepatic steatosis has been described as a common finding in adults following total pancreatectomy with islet autotransplantation (TPIAT) but it is unknown if this occurs in children and adolescents.ObjectivesTo define the frequency of post-TPIAT hepatic steatosis in a sample of children and adolescents and to identify clinical predictors of incident steatosis post-TPIAT.MethodsIn this prospective study, consecutive participants at least 1-month post-TPIAT underwent a liver MRI with proton density fat fraction (PDFF) and blood draw at our pediatric academic medical center between April 2021 and January 2022. Comparison clinical pre-TPIAT liver MRI or ultrasound and insulin use and graft function data were extracted from the medical record. T-tests were used for the comparison of means across continuous variables between participants with and without post-TPIAT steatosis.ResultsA total of 20 participants (mean: 13 ± 4 years; 12 female) were evaluated. Mean liver PDFF at research MRI was 7.4 ± 6.2% (range: 2–25%). Seven participants (35%) had categorical hepatic steatosis (PDFF>5%) post-TPIAT, five of whom had pre-TPIAT steatosis, reflecting a 13% (2/15; 95% CI: 2–40%) incidence of post-TPIAT steatosis. Participant characteristics were not significantly different between subgroups with and without post-TPIAT steatosis. Mean PDFF at research MRI was not different between graft function subgroups (7.5% optimal/good vs. 7.3% marginal/failure; p = .96).ConclusionOur study shows a moderate prevalence but low incidence of hepatic steatosis in a small sample of children and adolescents post-TPIAT. This study raises questions about a causal relationship between TPIAT and hepatic steatosis. 相似文献
9.
《Vaccine》2022,40(18):2525-2527
10.