全文获取类型
收费全文 | 38325篇 |
免费 | 3045篇 |
国内免费 | 81篇 |
专业分类
耳鼻咽喉 | 291篇 |
儿科学 | 1706篇 |
妇产科学 | 1184篇 |
基础医学 | 5185篇 |
口腔科学 | 401篇 |
临床医学 | 4651篇 |
内科学 | 7011篇 |
皮肤病学 | 681篇 |
神经病学 | 4513篇 |
特种医学 | 722篇 |
外科学 | 3710篇 |
综合类 | 353篇 |
现状与发展 | 1篇 |
一般理论 | 74篇 |
预防医学 | 5222篇 |
眼科学 | 596篇 |
药学 | 2504篇 |
中国医学 | 35篇 |
肿瘤学 | 2611篇 |
出版年
2024年 | 81篇 |
2023年 | 618篇 |
2022年 | 989篇 |
2021年 | 1951篇 |
2020年 | 1156篇 |
2019年 | 1674篇 |
2018年 | 1880篇 |
2017年 | 1271篇 |
2016年 | 1438篇 |
2015年 | 1494篇 |
2014年 | 1960篇 |
2013年 | 2459篇 |
2012年 | 3565篇 |
2011年 | 3448篇 |
2010年 | 1726篇 |
2009年 | 1483篇 |
2008年 | 2274篇 |
2007年 | 2364篇 |
2006年 | 1998篇 |
2005年 | 1832篇 |
2004年 | 1566篇 |
2003年 | 1293篇 |
2002年 | 1164篇 |
2001年 | 146篇 |
2000年 | 107篇 |
1999年 | 176篇 |
1998年 | 230篇 |
1997年 | 136篇 |
1996年 | 114篇 |
1995年 | 114篇 |
1994年 | 106篇 |
1993年 | 96篇 |
1992年 | 53篇 |
1991年 | 45篇 |
1990年 | 40篇 |
1989年 | 29篇 |
1988年 | 24篇 |
1987年 | 23篇 |
1986年 | 28篇 |
1985年 | 31篇 |
1984年 | 30篇 |
1983年 | 24篇 |
1982年 | 25篇 |
1981年 | 26篇 |
1980年 | 29篇 |
1979年 | 17篇 |
1978年 | 15篇 |
1977年 | 10篇 |
1974年 | 8篇 |
1972年 | 12篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
Anna Gossen Sarah E. Groppe Lina Winkler Gregor Kohls John Herrington Robert T. Schultz Gerhard Gründer Katja N. Spreckelmeyer 《Social cognitive and affective neuroscience》2014,9(5):661-670
Data from developmental psychology suggests a link between the growth of socio-emotional competences and the infant''s sensitivity to the salience of social stimuli. The aim of the present study was to find evidence for this relationship in healthy adults. Thirty-five participants were recruited based on their score above the 85th or below the 15th percentile of the empathy quotient questionnaire (EQ, Baron-Cohen and Wheelwright, 2004). Functional magnetic resonance imaging (fMRI) was used to compare neural responses to cues of social and non-social (monetary) reward. When compared to the high-EQ group, the low-EQ group showed reduced activity of the brain s reward system, specifically the right nucleus accumbens, in response to cues predictive of social reward (videos showing gestures of approval)—but increased activation in this area for monetary incentives. Our data provide evidence for a link between self-reported deficits in social proficiency and reduced sensitivity to the motivational salience of positive social stimuli. 相似文献
992.
Jacqueline Lutz Uwe Herwig Sarah Opialla Anna Hittmeyer Lutz J?ncke Michael Rufer Martin Grosse Holtforth Annette B. Brühl 《Social cognitive and affective neuroscience》2014,9(6):776-785
Mindfulness—an attentive non-judgmental focus on present experiences—is increasingly incorporated in psychotherapeutic treatments as a skill fostering emotion regulation. Neurobiological mechanisms of actively induced emotion regulation are associated with prefrontally mediated down-regulation of, for instance, the amygdala. We were interested in neurobiological correlates of a short mindfulness instruction during emotional arousal. Using functional magnetic resonance imaging, we investigated effects of a short mindfulness intervention during the cued expectation and perception of negative and potentially negative pictures (50% probability) in 24 healthy individuals compared to 22 controls. The mindfulness intervention was associated with increased activations in prefrontal regions during the expectation of negative and potentially negative pictures compared to controls. During the perception of negative stimuli, reduced activation was identified in regions involved in emotion processing (amygdala, parahippocampal gyrus). Prefrontal and right insular activations when expecting negative pictures correlated negatively with trait mindfulness, suggesting that more mindful individuals required less regulatory resources to attenuate emotional arousal. Our findings suggest emotion regulatory effects of a short mindfulness intervention on a neurobiological level. 相似文献
993.
Veronika I. Müller Tanja S. Kellermann Sarah C. Seligman Bruce I. Turetsky Simon B. Eickhoff 《Social cognitive and affective neuroscience》2014,9(4):436-444
Schizophrenia is a psychiatric disorder resulting in prominent impairments in social functioning. Thus, clinical research has focused on underlying deficits of emotion processing and their linkage to specific symptoms and neurobiological dysfunctions. Although there is substantial research investigating impairments in unimodal affect recognition, studies in schizophrenia exploring crossmodal emotion processing are rare. Therefore, event-related potentials were measured in 15 patients with schizophrenia and 15 healthy controls while rating the expression of happy, fearful and neutral faces and concurrently being distracted by emotional or neutral sounds. Compared with controls, patients with schizophrenia revealed significantly decreased P1 and increased P2 amplitudes in response to all faces, independent of emotion or concurrent sound. Analyzing these effects with regard to audiovisual (in)congruence revealed that P1 amplitudes in patients were only reduced in response to emotionally incongruent stimulus pairs, whereas similar amplitudes between groups could be observed for congruent conditions. Correlation analyses revealed a significant negative correlation between general symptom severity (Brief Psychiatric Rating Scale-V4) and P1 amplitudes in response to congruent audiovisual stimulus pairs. These results indicate that early visual processing deficits in schizophrenia are apparent during emotion processing but, depending on symptom severity, these deficits can be restored by presenting concurrent emotionally congruent sounds. 相似文献
994.
Background
Light information is sorted by neuronal circuits to generate image-forming (IF) (interpretation and tracking of visual objects and patterns) and non-image-forming (NIF) tasks. Among the NIF tasks, photic entrainment of circadian rhythms, the pupillary light reflex, and sleep are all associated with physiological responses, mediated mainly by a small group of melanopsin-expressing retinal ganglion cells (mRGCs). Using Xenopus laevis as a model system, and analyzing the c-fos expression induced by light as a surrogate marker of neural activity, we aimed to establish the developmental time at which the cells participating in both systems come on-line in the retina.Results
We found that the peripheral retina contains 80% of the two melanopsin-expressing cell types we identified in Xenopus: melanopsin-expressing horizontal cells (mHCs; opn4m+/opn4x+/Prox1+) and mRGCs (2.7% of the total RGCs; opn4m+/opn4x+/Pax6+/Isl1), in a ratio of 6:1. Only mRGCs induced c-fos expression in response to light. Dopaminergic (tyrosine hydroxylase-positive; TH+) amacrine cells (ACs) may be part of the melanopsin-mediated circuit, as shown by preferential c-fos induction by blue light. In the central retina, two cell types in the inner nuclear layer (INL) showed light-mediated induction of c-fos expression [(On-bipolar cells (Otx2+/Isl1+), and a sub-population of ACs (Pax6?/Isl1?)], as well as two RGC sub-populations (Isl1+/Pax6+ and Isl1+/Pax6?). Melanopsin and opsin expression turned on a day before the point at which c-fos expression could first be activated by light (Stage 37/38), in cells of both the classic vision circuit, and those that participate in the retinal component of the NIF circuit. Key to the classic vision circuit is that the component cells engage from the beginning as functional ‘unit circuits’ of two to three cells in the INL for every RGC, with subsequent growth of the vision circuit occurring by the wiring in of more units.Conclusions
We identified melanopsin-expressing cells and specific cell types in the INL and the RGC layer which induce c-fos expression in response to light, and we determined the developmental time when they become active. We suggest an initial formulation of retinal circuits corresponding to the classic vision pathway and melanopsin-mediated circuits to which they may contribute. 相似文献995.
996.
997.
998.
Candice Alexandra Grzelak Luciano Gastón Martelotto Nicholas David Sigglekow Bramilla Patkunanathan Katerina Ajami Sarah Ruth Calabro Benjamin James Dwyer Janina Elke Eleonore Tirnitz-Parker D. Neil Watkins Fiona Jane Warner Nicholas Adam Shackel Geoffrey William McCaughan 《Journal of hepatology》2014
999.
1000.