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   21201篇
  免费   2087篇
  国内免费   579篇
耳鼻咽喉   295篇
儿科学   540篇
妇产科学   345篇
基础医学   1295篇
口腔科学   363篇
临床医学   3259篇
内科学   3563篇
皮肤病学   294篇
神经病学   2070篇
特种医学   645篇
外国民族医学   2篇
外科学   2506篇
综合类   2742篇
现状与发展   2篇
一般理论   1篇
预防医学   1988篇
眼科学   243篇
药学   1775篇
  73篇
中国医学   1119篇
肿瘤学   747篇
  2024年   98篇
  2023年   750篇
  2022年   1092篇
  2021年   1842篇
  2020年   1669篇
  2019年   1440篇
  2018年   1388篇
  2017年   1181篇
  2016年   973篇
  2015年   867篇
  2014年   1703篇
  2013年   1662篇
  2012年   1197篇
  2011年   1216篇
  2010年   843篇
  2009年   854篇
  2008年   781篇
  2007年   733篇
  2006年   565篇
  2005年   451篇
  2004年   390篇
  2003年   308篇
  2002年   243篇
  2001年   205篇
  2000年   151篇
  1999年   129篇
  1998年   122篇
  1997年   110篇
  1996年   109篇
  1995年   82篇
  1994年   75篇
  1993年   80篇
  1992年   55篇
  1991年   61篇
  1990年   53篇
  1989年   46篇
  1988年   46篇
  1987年   40篇
  1986年   23篇
  1985年   52篇
  1984年   38篇
  1983年   23篇
  1982年   26篇
  1981年   13篇
  1980年   15篇
  1979年   15篇
  1978年   12篇
  1977年   11篇
  1976年   6篇
  1975年   14篇
排序方式: 共有10000条查询结果,搜索用时 140 毫秒
81.
To determine the prevalence of excessive daytime sleepiness (EDS) and that of dozing and sudden onset of sleep episodes (SOS) while driving in ambulatory patients with Parkinson's disease (PD) in France, a national sample of private and public neurologists was asked to recruit the first 10 consecutive nondemented PD patients. Each patient completed a questionnaire including the Epworth Sleepiness Scale (ESS) and the likelihood of dozing off and experiencing SOS episodes behind the wheel. Clinical and demographic data were collected. One thousand six hundred and twenty‐five patients with PD were included in the survey. Twenty‐nine percent of the patients suffered from EDS (ESS score ≥10) but only 0.8% declared a high chance of dozing while driving and 0.5% reported totally unpredictable SOS episodes while driving. Risk factors for EDS were male gender, reduced activity of daily living, and a high daily levodopa equivalent dosage. Risk factors for SOS episodes while driving were an ESS score ≥10, male gender, and low Hoehn and Yahr staging. EDS is common in ambulatory patients with PD and is a major risk factor for dozing and for SOS episodes behind the wheel in patients who drive. © 2007 Movement Disorder Society  相似文献   
82.
目的 研究能够增强吗啡镇痛效能的纳洛酮剂量范围.方法 84只雄性SD大鼠,取42只随机分为7组(n=6),即生理盐水组对照组(NS)、吗啡对照组(M组,皮下注射吗啡6mg/kg),吗啡复合纳洛酮组(MN组,皮下注射吗啡6mg/kg及纳洛酮),根据纳洛酮剂量的不同(分别为1μg/kg、100、10、1和0.1ng/kg),MN组又分为MN1、MN2、MN3、MN4和MN5组.测定各组大鼠在注药前及注药后不同时间点的痛阈.另外42只大鼠分组方法 同上,仅将M组和各MN组吗啡剂量改为2mg/kg,在大鼠后爪建立急性疼痛模型后,分别皮下注射生理盐水或相应药物,观察各组大鼠在1h内的累积疼痛评分.结果 与NS组比较,M组和各MN组大鼠的痛阈在5~120min显著增高(P<0.01);累积疼痛评分显著降低(P<0.01).与M组比较,MN1组大鼠在30、40、50min的疼痛阈值显著降低(P<0.01),累积疼痛评分升高(P<0.01);MN2、MN3、MN4组大鼠的疼痛阈值在注药后20~120min内显著升高(P<0.01),累积疼痛评分降低(P<0.05);MN5组疼痛阈值、累积疼痛评分与M组比较无统计学差异(P>0.05).结论 1~100ng/kg的纳洛酮能够增强吗啡对大鼠的镇痛效能,1μg/kg的纳洛酮可拮抗吗啡的镇痛效能,而剂量在0.1ng/kg时则不增强吗啡的镇痛效能.  相似文献   
83.
84.
85.
均衡组间差异的有效方法:倾向评分   总被引:4,自引:1,他引:3  
目的:实例介绍倾向评分法的基本原理和适用条件,设计适用于分析二分类资料的SAS宏程序。方法:运用倾向评分比较平衡前后两组间差异的改变情况,评价放弃心肺复苏急救与充血性心力衰竭患者院内死亡的联系。结果:采用分层法和匹配法都可以有效地平衡两组各个特征变量间所存在的高度差异,三种分析方法获得相近的估计结果。结论:倾向评分法是均衡组间差异的有效方法,能够匹配和平衡各个特征变量的作用,并用于分析各种观察性研究资料。  相似文献   
86.
CT影像学评分预测急性胰腺炎病情及转归的研究   总被引:2,自引:0,他引:2  
目的 探讨CT影像学评分对急性胰腺炎病情和转归的预测价值。方法 回顾性分析入院后经CT检查的急性胰腺炎46例,按一定的规则对每例患进行CT影像学评分与分型,并与临床治疗中的有关资料进行对照。结果 46例患CT评分后获得:轻型24例,中型13例,重型9例。轻型患较重型住院日少、恢复顺利,中转手术及死亡率均以重型为高。结论 CT评分对急性胰腺炎病情及预后评估具有重要意义。  相似文献   
87.
Early Stroke Recognition: Developing an Out-of-hospital NIH Stroke Scale   总被引:1,自引:0,他引:1  
Objective : To develop an abbreviated and practical neurologic scale that could assist emergency medical services or triage personnel in identifying patients with stroke.
Methods : A prospective, observational, cohort study was performed at university-based EDs. Participants were 74 patients treated in a thrombolytic stroke trial and 225 consecutive non-stroke patients evaluated during 4 random 12-hour shifts in the ED. Scores on the NIH Stroke Scale were obtained for all patients by physicians. Items of this scale were modified and recoded to a binomial (normal or abnormal) scale. Serial univariate analyses using χ2 were performed to rank items. Recursive partitioning was then performed to develop the decision rule for predicting the presence of stroke.
Results : Three items identified 100% of patients with stroke: facial palsy, motor arm, and dysarthria. An Abbreviated NIH Stroke Scale based on these items had a sensitivity of 100% and a specificity of 92%. A proposed Out-of-hospital NIH Stroke Scale consisting of facial palsy, motor arm, and a combination of dysarthria and best language items (abnormal speech) had a sensitivity of 100% and a specificity of 88%.
Conclusion : Using the derivation data set, a proposed Out-of-hospital NIH Stroke Scale had a high sensitivity and specificity for identifying patients with stroke when performed by physicians in this group of 299 ED patients. Prospective studies of other health care professionals using the scale in the out-of-hospital arena are needed.  相似文献   
88.
Restless legs syndrome in Parkinson's disease: a case-controlled study.   总被引:5,自引:0,他引:5  
Restless legs syndrome (RLS) is a disorder of motor activity with a circadian pattern, occurring frequently in patients with Parkinson's disease (PD). We sought to estimate the prevalence of RLS in Indian PD patients. One hundred twenty-six consecutive PD patients and 128 healthy age- and sex-matched controls were evaluated using a predesigned questionnaire. RLS was present in 10 of 126 cases of PD (7.9%) and 1 of 128 controls (0.8%, P = 0.01). PD patients with RLS were older than those without RLS (63.70 +/- 7.80 years vs. 57.37 +/- 10.04 years; P = 0.05) and had higher prevalence of depression (40% vs. 10.3%; P = 0.023). No demographic factors or factors related to PD correlated with the presence or severity of RLS. RLS is more common among patients with PD than controls. A greater medical recognition of this disorder is needed in view of available effective treatment.  相似文献   
89.
90.
Summary 115 traumatic extradural haematoma cases who were treated surgically at Cerrahpasa Medical Faculty Neurosurgery Department between 1987 and 1992 are evaluated.When factors affecting the outcome were examined, a strong correlation was found between the result andGlasgow coma scale (GCS) (p<0.00001). The existence of a fracture, the interval between onset of haematoma symptoms and intervention and the existence of an intracerebral haematoma together with contusion accompanying intradural haematoma, affect the outcome in a negative direction. There was no statistical correlation between the outcome and the age of patient, localization of the haematoma and aetiology.  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