全文获取类型
收费全文 | 26374篇 |
免费 | 3064篇 |
国内免费 | 835篇 |
专业分类
耳鼻咽喉 | 79篇 |
儿科学 | 619篇 |
妇产科学 | 237篇 |
基础医学 | 6528篇 |
口腔科学 | 375篇 |
临床医学 | 1919篇 |
内科学 | 4524篇 |
皮肤病学 | 423篇 |
神经病学 | 1931篇 |
特种医学 | 387篇 |
外国民族医学 | 4篇 |
外科学 | 1772篇 |
综合类 | 3390篇 |
现状与发展 | 13篇 |
一般理论 | 1篇 |
预防医学 | 1850篇 |
眼科学 | 322篇 |
药学 | 2377篇 |
10篇 | |
中国医学 | 1488篇 |
肿瘤学 | 2024篇 |
出版年
2024年 | 40篇 |
2023年 | 699篇 |
2022年 | 638篇 |
2021年 | 1509篇 |
2020年 | 1272篇 |
2019年 | 1104篇 |
2018年 | 1002篇 |
2017年 | 1141篇 |
2016年 | 1171篇 |
2015年 | 1141篇 |
2014年 | 1491篇 |
2013年 | 1977篇 |
2012年 | 1393篇 |
2011年 | 1386篇 |
2010年 | 1238篇 |
2009年 | 1197篇 |
2008年 | 1131篇 |
2007年 | 1098篇 |
2006年 | 1033篇 |
2005年 | 908篇 |
2004年 | 801篇 |
2003年 | 666篇 |
2002年 | 629篇 |
2001年 | 606篇 |
2000年 | 482篇 |
1999年 | 387篇 |
1998年 | 352篇 |
1997年 | 291篇 |
1996年 | 289篇 |
1995年 | 311篇 |
1994年 | 262篇 |
1993年 | 239篇 |
1992年 | 216篇 |
1991年 | 222篇 |
1990年 | 161篇 |
1989年 | 163篇 |
1988年 | 177篇 |
1987年 | 157篇 |
1986年 | 152篇 |
1985年 | 177篇 |
1984年 | 198篇 |
1983年 | 111篇 |
1982年 | 167篇 |
1981年 | 104篇 |
1980年 | 93篇 |
1979年 | 82篇 |
1978年 | 49篇 |
1977年 | 45篇 |
1976年 | 56篇 |
1973年 | 22篇 |
排序方式: 共有10000条查询结果,搜索用时 140 毫秒
11.
《Sleep medicine》2021
BackgroundInsomnia is prevalent among children and adolescents and is associated with a wide range of negative outcomes. Knowledge about its determinants is therefore important, but due to the lack of longitudinal studies, such knowledge is limited. The aim of the present inquiry is to identify child and family predictors of future pediatric insomnia within a psycho-bio-behavioral framework.MethodsA representative community sample (n = 1,037) was followed biennially from 4 to 14 years of age (2007–2017). Insomnia was defined based on the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) criteria and was diagnosed by a semistructured clinical interview of children (from age eight years of age) and parents (all ages). Predictors included parent ratings of child emotional reactivity, family functioning, and marital conflict; self-reports of personality; and teacher-rated emotion regulation skills.ResultsRandom intercept cross-lagged analyses revealed that within-person increases (ie, relative to the child's typical levels across childhood) in emotional reactivity and decreases in emotion regulation skills predicted insomnia diagnosis two years later from ages 4 to 14 after adjusting for previous insomnia and all unmeasured time-invariant factors. Previous insomnia was the strongest predictor of later insomnia, whereas family functioning and marital conflict did not predict insomnia.ConclusionsIncreases in emotional reactivity and decreases in emotion regulation skills predicted insomnia above and beyond all unmeasured time-invariant factors and could be targets for interventions. Previous insomnia predicted later insomnia, thereby underscoring the importance of detecting, preventing, and treating insomnia at an early age. 相似文献
12.
《Human brain mapping》2021,42(7):1945
Having the means to share research data openly is essential to modern science. For human research, a key aspect in this endeavor is obtaining consent from participants, not just to take part in a study, which is a basic ethical principle, but also to share their data with the scientific community. To ensure that the participants'' privacy is respected, national and/or supranational regulations and laws are in place. It is, however, not always clear to researchers what the implications of those are, nor how to comply with them. The Open Brain Consent (https://open-brain-consent.readthedocs.io) is an international initiative that aims to provide researchers in the brain imaging community with information about data sharing options and tools. We present here a short history of this project and its latest developments, and share pointers to consent forms, including a template consent form that is compliant with the EU general data protection regulation. We also share pointers to an associated data user agreement that is not only useful in the EU context, but also for any researchers dealing with personal (clinical) data elsewhere. 相似文献
13.
Sandra Pérez Andrea Masegoso Nazaret Hernández-Espeso 《Clinical psychology & psychotherapy》2021,28(3):606-614
Due to the COVID-19 pandemic's consequences and the state of alarm, literature has shown that people worldwide have experienced severe stressors that have been associated with increased prevalence of emotional distress. In this study, we explored psychological distress (depression, anxiety, and somatization symptoms) using an online survey platform in a sample of 1,781 Spanish adults during the confinement due to COVID-19, relationships between distress and sleep problems, affect, pain, sleep, emotional regulation, gender, type of housing, history of psychopathology, and living alone during the confinement, and differences depending on demographic and psychological variables. Results showed that between 25% and 39% of the sample referred to clinically significant levels of distress. In addition, women showed higher levels of distress, negative affect, perception of pain, and cognitive reappraisal and lower levels of emotional suppression and sleep quality than men. A history of psychopathology, being younger, living alone or in a flat was associated with higher distress. Finally, the variables most strongly related to distress were negative and positive affect, levels of pain, sleep quality, and emotional suppression. Our results highlight the important role of emotional suppression, cognitive reappraisal, and loneliness and the impact of being a woman and younger in Spain during the COVID-19 pandemic. Therefore, it would be necessary to provide assessments of distress levels in these population groups and focus psychological preventive and therapeutic online interventions on expressing emotions and preventing loneliness. 相似文献
14.
15.
16.
17.
18.
《Saudi Pharmaceutical Journal》2022,30(6):655-668
Most vaccines approved by regulatory bodies are administered via intramuscular or subcutaneous injections and have shortcomings, such as the risk of needle-associated blood infections, pain and swelling at the injection site. Orally administered vaccines are of interest, as they elicit both systemic and mucosal immunities, in which mucosal immunity would neutralize the mucosa invading pathogen before the onset of an infection. Hence, oral vaccination can eliminate the injection associated adverse effects and enhance the person's compliance. Conventional approaches to manufacturing oral vaccines, such as coacervation, spray drying, and membrane emulsification, tend to alter the structural proteins in vaccines that result from high temperature, organic and toxic solvents during production. Electrohydrodynamic processes, specifically electrospraying, could solve these challenges, as it also modulates antigen release and has a high loading efficiency. This review will highlight the mucosal immunity and biological basis of the gastrointestinal immune system, different oral vaccine delivery approaches, and the application of electrospraying in vaccines development. 相似文献
19.
20.
Platelets have diverse roles in immune processes in addition to their key functions in haemostasis and thrombosis. Some studies imply that platelets may be possibly related to the immune tolerance induction. However, the role of platelets in the development of immune tolerance is not fully understood. The purpose of this study was to investigate the role of platelets in the development of regulatory mechanisms responsible for cutaneous inflammation using a mouse model of low zone tolerance (LZT). Mice were treated with 2,4,6‐trinitro‐1‐chlorobenzene (TNCB) 8 times every other day for tolerance induction with administration of anti‐platelet antibody or control antibody during the tolerance induction phase every 3 days. After the treatment for the tolerance induction, mice were sensitized and then challenged with TNCB. The contact hypersensitivity (CHS) was significantly decreased at 24 hours after challenge in the mice with LZT than in those without LZT. Platelet depletion via administration of anti‐platelet antibody reversed the inhibition of CHS and reduced the frequency of Foxp3+ Tregs in the inflamed skin and draining lymph nodes in mice with LZT. In addition, repeated low‐dose skin exposure resulted in elevated plasma levels of transforming growth factor (TGF)‐β1. Interestingly, platelet depletion reduced plasma TGF‐β1 levels of mice with LZT. Furthermore, the CHS response was reduced by administration of recombinant TGF‐β1 during platelet depletion in mice with LZT. Administration of anti‐TGF‐β antibody reversed the inhibition of the CHS responses. These results suggest that platelets are involved in the induction of immune tolerance via the release of TGF‐β1. 相似文献