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   31301篇
  免费   2847篇
  国内免费   1110篇
耳鼻咽喉   151篇
儿科学   300篇
妇产科学   269篇
基础医学   1650篇
口腔科学   161篇
临床医学   6486篇
内科学   3815篇
皮肤病学   81篇
神经病学   6499篇
特种医学   919篇
外科学   2476篇
综合类   4664篇
现状与发展   3篇
预防医学   2197篇
眼科学   150篇
药学   2745篇
  57篇
中国医学   2231篇
肿瘤学   404篇
  2024年   706篇
  2023年   886篇
  2022年   1463篇
  2021年   2049篇
  2020年   1939篇
  2019年   1563篇
  2018年   1542篇
  2017年   1506篇
  2016年   1458篇
  2015年   1264篇
  2014年   2425篇
  2013年   2680篇
  2012年   1992篇
  2011年   1848篇
  2010年   1529篇
  2009年   1254篇
  2008年   1209篇
  2007年   1202篇
  2006年   1049篇
  2005年   821篇
  2004年   656篇
  2003年   580篇
  2002年   567篇
  2001年   421篇
  2000年   329篇
  1999年   297篇
  1998年   231篇
  1997年   188篇
  1996年   158篇
  1995年   147篇
  1994年   150篇
  1993年   121篇
  1992年   89篇
  1991年   89篇
  1990年   90篇
  1989年   77篇
  1988年   80篇
  1987年   68篇
  1986年   75篇
  1985年   66篇
  1984年   67篇
  1983年   45篇
  1982年   47篇
  1981年   53篇
  1980年   29篇
  1979年   30篇
  1978年   24篇
  1977年   18篇
  1976年   24篇
  1975年   15篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
11.
12.
Transient ischaemic attack (TIA) and minor stroke are characterized by short‐lasting symptoms; however, anecdotal and empirical evidence suggests that these patients experience ongoing cognitive/psychological impairment for which they are not routinely treated. The aims were (i) to investigate the prevalence and time course of fatigue, anxiety, depression, post‐traumatic stress disorder(PTSD) and cognitive impairment following TIA/minor stroke; (ii) to explore the impact on quality of life (QoL), change in emotions and return to work; and (iii) to identify where further research is required and potentially inform an intervention study. A systematic review of MEDLINE, EMBASE, PSYCINFO, CINAHL, the Cochrane libraries and the grey literature between January 1993 and April 2013 was undertaken. Literature was screened and data were extracted by two independent reviewers. Studies were included of adult TIA/minor stroke participants with any of the outcomes of interest: fatigue, anxiety, depression, PTSD, cognitive impairment, QoL, change in emotions and return to work. Random‐effects meta‐analysis pooled outcomes by measurement tool. Searches identified 5976 records, 289 were assessed for eligibility and 31 studies were included. Results suggest high levels of cognitive impairment and depression post‐TIA/minor stroke which decreased over time. However, frequencies varied between studies. Limited information was available on anxiety, PTSD and fatigue. Meta‐analysis revealed that the measurement tool administered influenced the prevalence of cognitive impairment: Mini‐Mental State Examination 17% [95% confidence interval (CI) 7, 26]; neuropsychological test battery 39% (95% CI 28, 50); Montreal Cognitive Assessment 54% (95% CI 43, 66). There is evidence to suggest that TIA/minor stroke patients may experience residual impairments; however, results should be interpreted with caution because of the few high quality studies. Notwithstanding, it is important to raise awareness of potential subtle but meaningful residual impairments.  相似文献   
13.
14.
15.
16.
17.
In this study we determined the short-term effects of a glucose drink and a sucrose drink compared to a placebo on cognitive performance and mood in elderly people with subjective, mild memory complaints using a randomized crossover study design. In total, 43 nondiabetic older adults with self-reported memory complaints were included. Drinks consisted of 250 ml with dissolved glucose (50 g), sucrose (100 g), or a mixture of artificial sweeteners (placebo). Multiple neuropsychological tests were performed and were combined by means of z scores into four cognitive domains: episodic memory, working memory, attention and information (processing speed), and executive functioning. Mood was assessed with the short Profile of Mood Status (s-POMS) questionnaire. Blood glucose concentrations were measured at five time points to divide participants into those with a better or poorer blood glucose recovery. Performance on the domain of attention and information processing speed was significantly better after consuming the sucrose drink (domain score of 0.06, SD = 0.91) than after the placebo drink (–0.08, SD = 0.92, p = .04). Sucrose had no effect on the other three domains, and glucose had no effect on any of the domains compared to the placebo. When dividing participants into poorer or better glucose recoverers, the beneficial effect of sucrose on attention and information processing speed was only seen in participants with a poorer recovery. After sucrose consumption, depressive feelings and tension were slightly higher than after the placebo. To conclude, 100 g sucrose, but not 50 g glucose, optimized attention and information processing speed in the short term in this study in elderly people with subjective, mild memory complaints.  相似文献   
18.
19.
Traumatic brain injury (TBI) causes microglial activation and related neurotoxicity that contributes to chronic neurodegeneration and loss of neurological function. Selective activation of metabotropic glutamate receptor 5 (mGluR5) by the orthosteric agonist (RS)-2-chloro-5-hydroxyphenylglycine (CHPG), is neuroprotective in experimental models of TBI, and has potent anti-inflammatory effects in vitro. However, the therapeutic potential of CHPG is limited due to its relatively weak potency and brain permeability. Highly potent, selective and brain penetrant mGluR5 positive allosteric modulators (PAMs) have been developed and show promise as therapeutic agents. We evaluated the therapeutic potential of a novel mGluR5 PAM, VU0360172, after controlled cortical impact (CCI) in mice. Vehicle, VU0360172, or VU0360172 plus mGluR5 antagonist (MTEP), were administered systemically to CCI mice at 3 h post-injury; lesion volume, hippocampal neurodegeneration, microglial activation, and functional recovery were assessed through 28 days post-injury. Anti-inflammatory effects of VU0360172 were also examined in vitro using BV2 and primary microglia. VU0360172 treatment significantly reduced the lesion, attenuated hippocampal neurodegeneration, and improved motor function recovery after CCI. Effects were mediated by mGluR5 as co-administration of MTEP blocked the protective effects of VU0360172. VU0360172 significantly reduced CD68 and NOX2 expression in activated microglia in the cortex at 28 days post-injury, and also suppressed pro-inflammatory signaling pathways in BV2 and primary microglia. In addition, VU0360172 treatment shifted the balance between M1/M2 microglial activation states towards an M2 pro-repair phenotype. This study demonstrates that VU0360172 confers neuroprotection after experimental TBI, and suggests that mGluR5 PAMs may be promising therapeutic agents for head injury.

Electronic supplementary material

The online version of this article (doi:10.1007/s13311-014-0298-6) contains supplementary material, which is available to authorized users.  相似文献   
20.
目的:探讨血小板参数与缺血性脑卒中患者颈动脉狭窄的相关性。方法选取2012-01-2013-10在我院住院治疗的急性缺血性脑卒中患者98例及同期健康体检者60例,动脉超声检查受检者有无颈动脉颅外段狭窄及其程度,全自动血细胞分析仪检测所有入组对象血小板参数各项值,并进行比较。结果伴颈动脉狭窄卒中组血小板计数(PL T )最低,而血小板平均体积(MPV)、血小板分布宽度(PDW)最大(P<0.05);颈动脉狭窄患者PLT、MPV及PDW较不伴颈动脉狭窄者均有显著差异(P<0.05)。缺血性脑卒中患者不伴动脉狭窄组血小板参数比较,仅MPV 水平差异有统计学意义(P<0.05)。相关性分析发现MPV与颈动脉狭窄程度呈正相关(P<0.05)。结论血小板参数与缺血性脑卒中颈动脉狭窄及程度密切相关。  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