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   2143篇
  免费   379篇
  国内免费   94篇
耳鼻咽喉   22篇
儿科学   54篇
妇产科学   16篇
基础医学   221篇
口腔科学   34篇
临床医学   412篇
内科学   101篇
皮肤病学   5篇
神经病学   124篇
特种医学   35篇
外科学   96篇
综合类   643篇
一般理论   1篇
预防医学   301篇
眼科学   12篇
药学   89篇
  9篇
中国医学   410篇
肿瘤学   31篇
  2024年   9篇
  2023年   39篇
  2022年   56篇
  2021年   123篇
  2020年   114篇
  2019年   97篇
  2018年   82篇
  2017年   97篇
  2016年   100篇
  2015年   96篇
  2014年   182篇
  2013年   408篇
  2012年   149篇
  2011年   163篇
  2010年   101篇
  2009年   92篇
  2008年   84篇
  2007年   103篇
  2006年   94篇
  2005年   57篇
  2004年   58篇
  2003年   58篇
  2002年   39篇
  2001年   34篇
  2000年   49篇
  1999年   30篇
  1998年   20篇
  1997年   12篇
  1996年   7篇
  1995年   12篇
  1994年   7篇
  1993年   10篇
  1992年   4篇
  1991年   8篇
  1990年   5篇
  1989年   3篇
  1988年   1篇
  1987年   1篇
  1986年   2篇
  1985年   2篇
  1984年   1篇
  1983年   1篇
  1982年   2篇
  1979年   1篇
  1978年   2篇
  1977年   1篇
排序方式: 共有2616条查询结果,搜索用时 31 毫秒
71.
Indicators of early research productivity among primary care fellows   总被引:1,自引:0,他引:1  
OBJECTIVE: Little is known about the impact of fellowship training in primary care on subsequent research productivity. Our goal was to identify characteristics of research fellows and their training associated with subsequent publications and research funding. DESIGN: Mail survey in 1998. SETTING AND PARTICIPANTS: 1988-1997 graduates of 25 National Research Service Award primary care research fellowships in the United States. OUTCOME MEASURES: 1) Publishing 1 or more papers per year since the beginning of fellowship, or 2) serving as principal investigator (PI) on a federal or non-federal grant. RESULTS: One hundred forty-six of two hundred fifteen program graduates (68%) completed the survey. The median age was 38 years, and 51% were male. Thirty-two percent had published 1 or more papers per year, and 44% were PIs. Male gender (odds ratio [OR], 3.6; 95% confidence interval [95% CI], 1.4 to 9.2), self-reported allocation of 40% or more of fellowship time to research (OR, 4.4; 95% CI, 1.8 to 11.2), and having an influential mentor during fellowship (OR, 5.0; 95% CI, 1.5 to 17.2) were independently associated with publishing 1 or more papers per year. Fellows with funding as a PI were also more likely to have an influential mentor (OR, 3.0; 95% CI, 1.3 to 7.2). CONCLUSION: Primary care fellows who had influential mentors were more productive in research early after fellowship. Awareness of the indicators of early research success can inform the policies of agencies that fund research training and the curricula of training programs themselves.  相似文献   
72.
[目的]分析我国护理期刊学术影响力排名,综合评价我国21种护理学统计源期刊学术影响力。[方法]以2014年版《中国科技期刊引证报告》(扩刊版)中21种护理期刊为研究对象,以总被引频次、影响因子、他引总引比、高被引论文数、来源文献量、平均引文数、地区分布数、Web下载量共8项指标为依据,赋予各项指标不同的权重,运用归一化加权法综合评价21种护理期刊的学术影响力。[结果]2014年21种护理学统计源期刊与全国6 345种科技期刊6项评价指标比较显示,总被引频次、影响因子、他引总引比、来源文献量、地区分布数5项评价指标均显著高于科技期刊平均水平,但平均引文数显著低于我国科技期刊的平均水平;运用多指标归一化加权法得出21种护理学统计源期刊的综合值,排名前5位的依次为《中华护理杂志》《护理研究》《中国实用护理杂志》《护士进修杂志》和《护理学杂志》;将本研究护理核心期刊排名情况与《中国科技期刊引证报告》进行比较,部分期刊在2个评价体系中排名有不同程度的上升或下降,存在综合值排名与影响因子排名分离的现象。[结论]我国护理期刊整体影响力较科技期刊平均水平高,但护理科研论文质量较其他科技期刊存在较大差距;运用多指标数据归一化加权法综合评价我国21种护理学统计源期刊的学术影响力,能作出全面、科学、准确的评价,真实反映护理期刊的影响力,能够为护理学术期刊自身发展及提高期刊影响力提供改进方向。  相似文献   
73.
BackgroundStress is an extremely adaptive phenomenon in human beings and cortisol is a known stress hormone. Examination has been described as a naturalistic stressor capable of affecting human health.ObjectivesTo estimate the relationship between serum cortisol, adrenaline, fasting blood glucose (FBG) and lipid profile during examination stress.MethodsTwo hundred and eight (208) apparently-healthy undergraduate students (aged, 24 ± 6 years) were involved in the study. Exactly 5 mls of venous blood was collected from each subject 1–3 hours before a major examination. A second assessment was done on the same students 3–4 weeks before any examination (control samples). Cortisol and adrenaline were assayed using ELISA techniques, FBG was assayed using enzymatic method while lipid parameters were assayed using standard enzymatic-spectrophotometric methods.ResultsThere was statistically significant increase in serum cortisol, adrenaline, Total cholesterol, HDL-cholesterol and LDL-cholesterol levels in students under examination stress compared to the non examination period (p=0.001, 0.013, 0.0001, 0.0001 and 0.0001, respectively). FBG showed no significant increase. There was also significant positive correlation (r=0.297, p=0.032) between serum cortisol and TC/HDL ratio (cardiac risk factor) before examination stress but not during the stress period.ConclusionsSignificant positive correlation was observed between cortisol and TC/HDL ratio before examination stress.  相似文献   
74.
本研究旨在探讨高校科技期刊如何在了解自身需求的基础上,去认识、利用、开发数字化平台,从而更有效的促进期刊内容快速的传播、推进期刊编辑部的办公流程、获取与分享期刊信息与资源,从而整体提高高校学术期刊的学术水平和出版质量。  相似文献   
75.
AIM:To evaluate significant risk factors for incomplete colonoscopy at a Japanese academic hospital.METHODS:A total of 11812 consecutive Japanese people were identified who underwent a colonoscopy at an academic hospital.A multiple logistic regression model was used to evaluate retrospectively the significant risk factors for incomplete colonoscopy.RESULTS:The cecal intubation rate was 95.0%.By univariate analysis,age,female sex,poor bowel cleansing,and a history of abdominal or pelvic surgery were significant risk factors for incomplete colonoscopy(P<0.001).Moreover,age-and sex-adjusted analysis showed that significant risk factors for incomplete colonoscopy were female sex(OR=1.38,95%CI:1.17-1.64,P=0.0002),age≥60 years old(OR=1.44,95%CI:1.22-1.71,P<0.0001),a history of prior abdominal or pelvic surgery(OR=1.55,95%CI:1.28-1.86,P<0.0001),poor bowel cleansing(OR=4.64,95%CI:3.69-5.84,P<0.0001),and inflammatory bowel disease(IBD)(OR=1.48,95%CI:1.13-1.95,P=0.0048).In Japanese men,by age-adjusted analysis,IBD(OR=1.69,95%CI:1.18-2.43,P=0.005)was an independent risk factor for incomplete colonoscopy.CONCLUSION:Several characteristics in the Japanese population were identified that could predict technical difficulty with colonoscopy.  相似文献   
76.
77.
[目的]探讨王邦才教授对叶天士重要理论"上下交损当治其中"的发微及临床应用。[方法]通过采集与分析王邦才教授采用"上下交损当治其中"理论治疗的临床病例,结合历代名医相关论述,进一步分析王教授对该理论的阐述和补充,以及运用该理论治疗病机复杂的疑难杂症的用药特色,并列举验案加以佐证。[结果]王邦才教授应用"上下交损当治其中"理论娴熟,结合中焦病理生理特性,兼顾上焦下焦整体的关系,治中焦而得全局,使脾胃运化正常、气机调达。确立治则和方药时注意纳运合宜,着力升降润燥;三因制宜,兼顾环境影响,用药注重寒热同调、燥湿相济、升降相用、补泄兼施、身心同治。对中风重症脾胃失健,气血两虚上下交病者,治以健脾益气、养血和营,方用归芍异功散合黄芪桂枝五物汤;对积聚脾肾两虚、湿热蕴结病机疑难者,予固护脾胃、扶正祛邪,方用附子米仁败酱汤合香砂六君汤加减,总以脾胃为枢、中洲为要,均获得较好的临床疗效。[结论]王邦才教授对"上下交损当治其中"理论的发微,强调了"治中焦"的意义,其经验值得临床推广学习。  相似文献   
78.
阐述移动身份认证技术路径实现原理,以中国医学科学院图书馆虚拟专用网络(VPN)使用数据为参照,重点以2020年2月日志数据为样本,对比分析协和移动身份认证(PUMC ID)和WebVPN的用户访问和数据库利用情况,结合服务效果探讨图书馆建设移动身份认证系统时应考虑的问题,以期为学术型图书馆开展移动访问服务提供参考。  相似文献   
79.
80.
作为一种新发的传染性极强的呼吸道疾病,新型冠状病毒肺炎(COVID-19,以下简称新冠肺炎)在全球范围内传播、蔓延。目前,该病已经造成了数以百万计的人感染、近30万人死亡,严重威胁着人类生命财产安全等众多方面。本文通过在临床治疗过程中对该疾病特点及疾病演变规律的总结,为新冠肺炎的诊治提供参考。  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