首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   4105篇
  免费   560篇
  国内免费   51篇
耳鼻咽喉   49篇
儿科学   345篇
妇产科学   11篇
基础医学   866篇
口腔科学   17篇
临床医学   246篇
内科学   190篇
皮肤病学   7篇
神经病学   1729篇
特种医学   44篇
外科学   125篇
综合类   165篇
预防医学   413篇
眼科学   171篇
药学   267篇
中国医学   57篇
肿瘤学   14篇
  2024年   5篇
  2023年   51篇
  2022年   74篇
  2021年   147篇
  2020年   174篇
  2019年   160篇
  2018年   168篇
  2017年   154篇
  2016年   181篇
  2015年   183篇
  2014年   215篇
  2013年   367篇
  2012年   230篇
  2011年   324篇
  2010年   224篇
  2009年   223篇
  2008年   216篇
  2007年   241篇
  2006年   242篇
  2005年   182篇
  2004年   138篇
  2003年   113篇
  2002年   120篇
  2001年   75篇
  2000年   61篇
  1999年   39篇
  1998年   49篇
  1997年   33篇
  1996年   28篇
  1995年   40篇
  1994年   25篇
  1993年   30篇
  1992年   14篇
  1991年   19篇
  1990年   15篇
  1989年   12篇
  1988年   12篇
  1987年   13篇
  1986年   9篇
  1985年   20篇
  1984年   16篇
  1983年   12篇
  1982年   17篇
  1981年   7篇
  1980年   9篇
  1979年   5篇
  1978年   5篇
  1977年   7篇
  1974年   2篇
  1973年   2篇
排序方式: 共有4716条查询结果,搜索用时 18 毫秒
1.
ADHD儿童认知障碍的主要特征之一是执行功能损害,涉及包括前额叶皮层在内的特定脑区域及多层级脑网络异常。执行功能按照功能性分为冷-热两方面:冷执行功能损害主要表现于反应抑制、工作记忆以及认知灵活性等;热执行功能损害通常涉及延迟满足、赏罚相关决策、自我调节及情绪调节等。ADHD儿童的执行功能评估应基于可信范式进行文化适应性调整。临床干预不能单一聚焦于冷执行功能,需关注儿童的身体发育以及热执行功能(情绪社会方面)的发展进程,结合其他共病与心理状况,进行全面的动态随访与干预,以达到最佳的长期疗效。  相似文献   
2.
3.
4.
Previous event-related potential (ERP) studies show that a salient lateral sound activates the visual cortex more strongly contralateral to the sound, observed as an auditory-evoked contralateral occipital positivity (ACOP). Studies showed that this activation enhances the early cortical processing of co-localized visual stimuli presented after, reflected by better detection rates, better discrimination, and sharper perceived contrast. We replicated the ACOP, using earphones, and tested whether auditory cuing can influence temporal order judgments (TOJ) for two visual stimuli (horizontal arrangement) as well as if the ACOP would predict the amplitude of this influence. A lateral salient sound was followed, after 150 or 630 ms, by the visual presentation of a pair of disks, one in left and one in right hemifield, with variable SOA. The TOJ task was to indicate which disk appeared first or which disk appeared second (controlling for response bias). We observed an ACOP at posterior electrode sites and confirmed our hypothesis that the lateral sound influenced TOJ by accelerating the perception of the disk presented on the cued side, even though the sound was irrelevant to the task. Furthermore, the ACOP amplitude was correlated to this visual perceptual change, indicating that a larger change in brain activity was associated with a faster processing of co-localized visual stimuli.  相似文献   
5.
IntroductionTinnitus is characterized by the presence of a sound in the absence of external sound stimulus. In individuals with normal audiometry, it may be associated with auditory attention difficulty, especially in those who report high tinnitus annoyance.ObjectiveTo investigate auditory attention ability in individuals with tinnitus complaint.MethodsCross-sectional analytical observational study. We evaluated 30 volunteers with normal hearing (up to 25 dBHL): 15 with tinnitus (test group) and 15 with no complaints (control group), aged between 18-40 years. The volunteers answered the tinnitus handicap inventory questionnaire and a visual analogue scale. Subsequently, a basic audiological evaluation (meatoscopy, tonal and vocal audiometry, and imittanciometry) and psychoacoustic measures of tinnitus (loudness and pitch) were performed. To evaluate auditory attention, the following tests were performed: auditory cognitive evoked potential (P300), central auditory processing tests (dichotic digits test and speech-in-noise test) and sustained auditory attention ability test.ResultsIn the tinnitus handicap inventory, individuals with tinnitus had a mean score of 37.78 (±27.05), characterized as moderate degree. In the dichotic digits test (binaural separation), a difference was observed between the groups in both ears. Moreover, there was a difference in the speech-in-noise test in both ears (RE: p = 0.044; LE: p = 0.019), in P300 (p = 0.049) and in total sustained auditory attention ability test (p = 0.032). Also, there is a negative correlation between sustained auditory attention ability test, decrease in attentiveness and binaural integration (RE: p = 0.044; LE: p = 0.048).ConclusionsIndividuals with tinnitus had a poorer performance compared to the control group regarding auditory attention ability. Therefore, it is inferred that tinnitus is associated with poor performance in selective and sustained auditory attention in the assessed volunteers. These aspects should be considered for the management of patients with tinnitus.  相似文献   
6.
7.
White matter bundles linking gray matter nodes are key anatomical players to fully characterize associations between brain systems and cognitive functions. Here we used a multivariate lesion inference approach grounded in coalitional game theory (multiperturbation Shapley value analysis, MSA) to infer causal contributions of white matter bundles to visuospatial orienting of attention. Our work is based on the characterization of the lesion patterns of 25 right hemisphere stroke patients and the causal analysis of their impact on three neuropsychological tasks: line bisection, letter cancellation, and bells cancellation. We report that, out of the 11 white matter bundles included in our MSA coalitions, the optic radiations, the inferior fronto‐occipital fasciculus and the anterior cingulum were the only tracts to display task‐invariant contributions (positive, positive, and negative, respectively) to the tasks. We also report task‐dependent influences for the branches of the superior longitudinal fasciculus and the posterior cingulum. By extending prior findings to white matter tracts linking key gray matter nodes, we further characterize from a network perspective the anatomical basis of visual and attentional orienting processes. The knowledge about interactions patterns mediated by white matter tracts linking cortical nodes of attention orienting networks, consolidated by further studies, may help develop and customize brain stimulation approaches for the rehabilitation of visuospatial neglect.  相似文献   
8.
Event‐related potentials (ERPs) are used extensively to investigate the neural mechanisms of attention control and selection. The univariate ERP approach, however, has left important questions inadequately answered. We addressed two questions by applying multivariate pattern classification to multichannel ERPs in two cued visual spatial attention experiments (N = 56): (a) impact of cueing strategies (instructional vs. probabilistic) on attention control and selection and (b) neural and behavioral effects of individual differences. Following cue onset, the decoding accuracy (cue left vs. cue right) began to rise above chance level earlier and remained higher in instructional cueing (~80 ms) than in probabilistic cueing (~160 ms), suggesting that unilateral attention focus leads to earlier and more distinct formation of the attention control set. A similar temporal sequence was also found for target‐related processing (cued target vs. uncued target), suggesting earlier and stronger attention selection under instructional cueing. Across the two experiments: (a) individuals with higher cue‐related decoding accuracy showed higher magnitude of attentional modulation of target‐evoked N1 amplitude, suggesting that better formation of anticipatory attentional state leads to stronger modulation of target processing, and (b) individuals with higher target‐related decoding accuracy showed faster reaction times (or larger cueing effects), suggesting that stronger selection of task‐relevant information leads to better behavioral performance. Taken together, multichannel ERPs combined with machine learning decoding yields new insights into attention control and selection that complement the univariate ERP approach, and along with the univariate ERP approach, provides a more comprehensive methodology to the study of visual spatial attention.  相似文献   
9.
目的本研究采用事件相关电位(ERPs)技术探讨前庭刺激对人脑加工功能的影响。方法选取15名健康男子进行实验。实验中受试者坐于转椅上,在下述条件下完成视觉操作任务:(1)实验测试,(2)对照测试,同时记录原始脑电资料。结果前庭刺激后,结果显示CPZ和PZ位置得到的差异波振幅均可见有显著性的改变,在前庭刺激后均明显减小。结论前庭刺激对人体的其他功能产生了明显影响,受试者在对视觉信号的感知时,特别是对需要选择的信号,明显产生了抑制现象。  相似文献   
10.
BackgroundChildren with visual impairments (VIs) face challenges in social play activities, which limits their opportunities to practice social skills.AimsWe investigated whether augmented toys were effective to facilitate play in 52 children with VIs who attended special schools for students with visual impairments and blindness.Methods and procedures52 children with VIs (mean age: 9.22 years, SD = 2.07) played three times with both an augmented and a non-augmented toy. A Playmobil® knight’s castle was augmented with Radio Frequency Identification (RFID) technology, such that each play figure produced audio feedback during play. The RFID-technology could be activated and deactivated. Social and cognitive aspects of play were coded from video and data were analyzed using multilevel logistics.Outcomes and resultsChildren showed less disengagement and more parallel play, but less cooperative play when they used the augmented versus the non-augmented castle. This pattern persisted after repeated play sessions with both toys.ConclusionsThe addition of sounds to physical toys increased shared attention between children with VIs during the exploration of play materials, yet it interfered with social interaction during peer play.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号