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   9233篇
  免费   618篇
  国内免费   58篇
耳鼻咽喉   59篇
儿科学   186篇
妇产科学   45篇
基础医学   1314篇
口腔科学   31篇
临床医学   994篇
内科学   827篇
皮肤病学   15篇
神经病学   3138篇
特种医学   146篇
外科学   321篇
综合类   1158篇
预防医学   732篇
眼科学   10篇
药学   645篇
  8篇
中国医学   201篇
肿瘤学   79篇
  2024年   20篇
  2023年   191篇
  2022年   368篇
  2021年   579篇
  2020年   520篇
  2019年   418篇
  2018年   400篇
  2017年   496篇
  2016年   442篇
  2015年   330篇
  2014年   872篇
  2013年   906篇
  2012年   574篇
  2011年   671篇
  2010年   453篇
  2009年   441篇
  2008年   424篇
  2007年   363篇
  2006年   290篇
  2005年   215篇
  2004年   146篇
  2003年   143篇
  2002年   98篇
  2001年   73篇
  2000年   54篇
  1999年   45篇
  1998年   48篇
  1997年   27篇
  1996年   31篇
  1995年   29篇
  1994年   32篇
  1993年   25篇
  1992年   19篇
  1991年   17篇
  1990年   25篇
  1989年   5篇
  1988年   12篇
  1987年   8篇
  1986年   10篇
  1985年   12篇
  1984年   5篇
  1983年   4篇
  1982年   7篇
  1981年   12篇
  1980年   6篇
  1979年   9篇
  1978年   4篇
  1974年   5篇
  1973年   5篇
  1971年   5篇
排序方式: 共有9909条查询结果,搜索用时 15 毫秒
31.
雌激素对慢性脑缺血大鼠认知功能及突触素的影响   总被引:5,自引:4,他引:1  
目的 研究苯甲酸雌二醇对慢性脑缺血大鼠认知功能及突触素的影响.方法 采用双侧颈总动脉永久性结扎制备慢性脑缺血模型,30只大鼠随机分为3组,A组:假手术组;B组:缺血组;C组:雌激素治疗组.各组于手术60d后,应用Y迷宫、免疫组化及图像分析系统测定大鼠认知功能及海马、齿状回突触素的含量.结果 治疗组较缺血组认知障碍明显改善(P<0.01),与假手术组相比,缺血组突触素的含量明显下降,治疗组以上变化明显减轻(P<0.01).结论 苯甲酸雌二醇能改善慢性脑缺血大鼠的认知功能,这可能与增加大鼠脑内突触素的含量有关.  相似文献   
32.
为促进聋幼儿各方面的正常发展,使其早日回归主流社会,我们对聋幼儿进行了认知和情绪表现的研究。通过问卷调查、观察和实验研究得知,聋幼儿的认知发展和良好情绪的培养是分不开的,认知内容适中有利于聋幼儿良好情绪的培养,而良好积极的情绪又可促进聋幼儿认知的发展。对此,我们实验并总结了培养聋幼儿积极情绪和促进认知发展的方法。  相似文献   
33.
39例慢性肾衰竭患者认知功能下降的调查   总被引:1,自引:0,他引:1  
目的通过神经心理测试等手段,探讨慢性肾衰竭(CRF)患者的认知状态。方法对39例40~60岁临床确诊为慢性肾衰竭的患者进行神经心理测试及人格和情绪状况测查,并对认知状态进行整体评定及分析。结果慢性肾衰竭患者认知功能测验成绩均低于对照组,并与人格的"精神质"和"情绪性"、健康自评等心理因素有关。"精神质"和"情绪性"越强,健康自评越差,认知障碍就越严重。慢性肾衰竭患者的焦虑和抑郁程度比对照组严重。结论慢性肾衰竭患者存在着认知能力下降,且与躯体和心理因素有关,并且随着肾功能的恶化,这种表现更加明显。  相似文献   
34.
目的评价认知疗法合并黛力新(氟哌噻吨/美利曲辛)治疗脑卒中后焦虑的疗效。方法将80例脑卒中后焦虑患者随机分为治疗组(n=40)和对照组(n=40),分别给予认知疗法合并黛力新、单用黛力新治疗8周。用汉密顿焦虑量表、副反应量表分别评定疗效和副反应。结果治疗4、8周时,治疗组汉密顿焦虑量表评分(16.08±7.45,8.80±4.73)明显低于对照组(19.80±8.26,11.35±5.03),P<0.05;临床总疗效无论治疗4、8周,治疗组均优于对照组,P<0.01。结论认知疗法合并黛力新治疗脑卒中后焦虑的疗效较好。  相似文献   
35.
目的探讨精神分裂症患者的语词记忆能力与认知电位之间的相互关系。方法对102例精神分裂症患者首先进行了听觉诱发电位P300测定,然后按有无P300潜伏期延长或/和波幅降低分为P300正常与异常组,再采用选择性提醒测验方法对其进行语词记忆测验。结果P300正常组30例在10次语词记忆测验中通过总例数28例,占93.3%,前6次通过的比例为56.7%;而P300异常组72例在10次语词记忆测验中通过的总例数只有43例,占59.7%,前6次通过的比例只有25%;两组之间的差异非常显著(P〈0.001)。P300异常组回忆总数、保持数、长时再现数及恒定长时再现数减少,而不恒定长时再现数、提醒总数及插入数显著增多,两组比较有显著性差异(P〈0.01)。结论P300异常的精神分裂症患者较P300正常的精神分裂症患者存在更严重的语词记忆障碍。  相似文献   
36.
Summary Ninety outpatients with Alzheimer's disease according to ICD-10 diagnostic draft criteria were studied to test the hypothesis that cases with a familial aggregation are different from cases without such an aggregation with respect to cognitive impairment. In all cases the diagnosis of Alzheimer's disease was confirmed by prospective observation within 12 months of initial evaluation. Patients were divided into two groups: one consisting of 23 patients with a familial aggregation, the other consisting of 67 patients without secondary cases among first-degree relatives. By means oft-tests differences in impairment of cognitive functions between the groups were calculated. The results did not yield statistically significant differences between the groups for any of the neuropsychologically investigated cognitive deficits. Thus the hypothesis that the presence of a familial aggregation may lead to a distinct phenotype in Alzheimer's disease was not confirmed.  相似文献   
37.
The course of the organic brain disease caused by human immunodeficency virus (HIV-1) was evaluated in a follow-up study. The primary material included 200 consecutive HIV-1 infected persons. Sixty-one subjects, in whom other brain-affecting factors were excluded, consented to the follow-up. They underwent 278 radiologic examinations: computed tomography, magnetic resonance imaging, or a combination of both (mean 4.6 examinations/subject). Clinical neurologic status and, in 40 subjects, cognitive performance were repeatedly evaluated. Sixteen subjects were followed up until death and 11 of them were autopsied. Median follow-up time was 27 mo (range 2.5–66 mo). The most common radiologic finding was atrophy, found in 19 subjects at study entry and developing in 10 subjects during the study. Twenty-four subjects (39%) showed the development and/or progression of atrophy. Atrophic changes progressed most rapidly in acquired immunodeficiency syndrome (AIDS), but mild developing/progressive atrophy was found even in 33% of asymptomatic or neurologically intact subjects. Cognitive and radiologic worsening were simultaneous in 6/7 subjects with declining neuropsychologic test performance. Signal intensity changes including HIV-1 leukoencephalopathy appeared in AIDS patients with clear cognitive decline.  相似文献   
38.
Background  Research has demonstrated that optimism and “positive illusions” can be used a coping mechanism among those facing adversity. Gamblers are a little studied group who also experience adversity and uncertainty. They often feel considerable levels of frustration, guilt, anger and a sense of feeling cheated after making significant losses. In order to deal with such feelings it is hypothesized that these individuals will search for positive consequences from their behaviour in order to offset this negative affect. Objectives  To (1) determine whether after gambling, gamblers compensate and reduce negative affect by identifying positive consequences from experiencing a loss, and (2) identify types of strategies which gamblers employ and consider how these should be classified. Materials and Methods  Eighty-seven regular slot machine gamblers were interviewed in a variety of environments housing slot machines. Each participant was asked a series of questions in a semi-structured format, to explore possible styles of positive thinking. Results  Nine types of ‘positive thinking’ experienced by gamblers were identified. These included Comparative thinking, Prophylactic thinking, Biased frequency thinking, Responsibility avoidance, Chasing Validation, Prioritization, Resourcefulness, Thoughtfulness, and Fear Reduction. Gamblers who were positive thinkers experienced significantly less guilt than non-positive thinkers. Conclusions  While reduction of negative affect may be perceived as positive in many other contexts, it is argued that it may counteract efforts to promote responsible gambling. Clinical implications and directions for future research are discussed.  相似文献   
39.
40.
Velo-cardio-facial syndrome (VCFS) is associated with deletions on the long arm of chromosome 22, mild intellectual disability, poor social interaction and a high prevalence of psychosis. However, to date there have been no studies investigating the neuropsychological functioning of adults with VCFS. We compared 19 adults with VCFS with 19 age, gender and IQ matched controls using a comprehensive neuropsychological battery. Compared to controls, adults with VCFS had significant impairments in visuoperceptual ability (Visual Object and Space Perception Battery), problem solving and planning (Tower of London) and abstract and social thinking (Comprehension WAIS-R). It is likely that haploinsufficiency (reduced gene dosage) of a neurodevelopmental gene or genes mapping to chromosome 22q11 underlies the cognitive deficits observed in individuals with VCFS.  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