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   154431篇
  免费   12204篇
  国内免费   4700篇
耳鼻咽喉   1387篇
儿科学   9515篇
妇产科学   4371篇
基础医学   17451篇
口腔科学   1702篇
临床医学   16349篇
内科学   32827篇
皮肤病学   2542篇
神经病学   10885篇
特种医学   3340篇
外国民族医学   7篇
外科学   12366篇
综合类   23221篇
现状与发展   26篇
预防医学   10016篇
眼科学   2298篇
药学   8675篇
  61篇
中国医学   12042篇
肿瘤学   2254篇
  2024年   260篇
  2023年   2457篇
  2022年   3865篇
  2021年   6810篇
  2020年   6321篇
  2019年   5353篇
  2018年   5306篇
  2017年   5427篇
  2016年   5820篇
  2015年   5583篇
  2014年   10597篇
  2013年   11002篇
  2012年   8944篇
  2011年   10413篇
  2010年   8009篇
  2009年   7712篇
  2008年   7544篇
  2007年   7732篇
  2006年   7153篇
  2005年   5879篇
  2004年   5053篇
  2003年   4429篇
  2002年   3272篇
  2001年   3082篇
  2000年   2657篇
  1999年   2348篇
  1998年   1945篇
  1997年   1813篇
  1996年   1721篇
  1995年   1666篇
  1994年   1423篇
  1993年   1248篇
  1992年   1114篇
  1991年   853篇
  1990年   775篇
  1989年   664篇
  1988年   646篇
  1987年   581篇
  1986年   485篇
  1985年   624篇
  1984年   513篇
  1983年   312篇
  1982年   405篇
  1981年   365篇
  1980年   297篇
  1979年   243篇
  1978年   167篇
  1977年   130篇
  1976年   100篇
  1975年   46篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
目的:观察PCR仪与测序仪在丙型肝炎病毒(HCV)基因型检测中的应用。方法:选择2018年1月~2018年12月收治的134例HCV感染患者为研究对象,给予患者PCR仪检测、测序仪检测。结果:测序仪检测134例均可分型,PCR仪检测130例患者可分型,4例未能分型。PCR检测结果:134例HCV感染患者中,1b型59例,2a型47例,3a型6例,3b型15例,6a型3例,4例为分出型别。基因测序结果:134例均可分型:1型59例,2a型40例,2i型7例,3a型6例,3b型15例,6a型3例,6n型4例。PCR仪检测法检测符合率97.0%。结论:PCR仪测序仪检测用于丙型肝炎病毒基因型检测,操作便捷,但其只能检测探针覆盖的型别,个别罕见型别不能分型。  相似文献   
72.
Purpose:Since the declaration of the lockdown due to COVID-19, the usage of digital devices has gone up across the globe, resulting in a challenge for the visual systems of all ages. The purpose of this study is to assess the impact of the lockdown on digital device usage, and consequently, the ocular surface health implications and circadian rhythm abnormalities related to digital eye strain.Methods:An open online survey was sent through various social media platforms and was open for a period of 2 weeks.Results:A total of 407 usable responses were obtained; the average age of respondents was 27.4 years. Typically, 93.6% of respondents reported an increase in their screen time since the lockdown was declared. The average increase in digital device usage was calculated at about 4.8 ± 2.8 h per day. The total usage per day was found to be 8.65 ± 3.74 hours. Sleep disturbances have been reported by 62.4% of people. Typically, 95.8% of respondents had experienced at least one symptom related to digital device usage, and 56.5% said that the frequency and intensity of these symptoms increased since the lockdown was declared.Conclusion:The study highlighted the drastic increase in use of digital devices after the initiation of the COVID-19 lockdown, and along with it, the slow deterioration of ocular health across all age groups. Awareness about prevention of digital eye strain should be stressed, and going forward, measures to bring these adverse effects to a minimum should be explored.  相似文献   
73.
74.
75.
76.
《Vaccine》2019,37(35):5059-5066
Background: Hepatitis B virus (HBV) infection is highly endemic in most low income countries including Cambodia. This nationwide serosurvey was conducted to assess the impact of hepatitis B vaccination and to determine whether Cambodia met the WHO regional 2017 target of hepatitis B surface antigen (HBsAg) seroprevalence less than 1% in five-year-old children.Methods: A cross-sectional multi-stage cluster survey was conducted among children born during 2010–2012 and their mothers in Cambodia. HBsAg prevalence was estimated by rapid point-of-care testing, and demographic data, including vaccination history, was collected. Vaccine coverage in children and the prevalence of HBsAg among children and mothers was calculated taking into account the complex survey design. Factors associated with children’s failure to receive timely (within 24 h) vaccination were analysed by multivariate logistic analysis.Findings: A total of 2,520 children 5–7 years old and 2,028 mothers were recruited. In total, 78.4% of children received hepatitis B vaccination birth-dose (HepB-BD); of these, 58.7% were administered ≤ 24 h. Birth at home or “other” location were independent risk factors for children’s failure to receive timely HepB-BD. Overall HBsAg seroprevalence was 4.39% (95%CI: 3.53%–5.45%) among mothers and 0.56% (95%CI: 0.32%–0.98%) among children. The prevalence among children without hepatitis B vaccination was 4.62% (95%CI: 1.31%–14.97%). Among children with a HBsAg-positive mother, prevalence was 10.11% (95%CI: 5.41%–18.11%).Interpretation: Having achieved the 2017 target of less than 1% HBsAg prevalence among 5 years old children, Cambodia can now focus on eliminating mother-to-child transmission of HBV. Moreover, the high HBsAg prevalence among mothers suggests that routine screening with proper linkage to care and treatment is needed. Strengthening measures to improve vaccination coverage further and eliminate mother-to-child transmission by coordinated programming with other services offering additional HBV interventions will help move towards the global goal of hepatitis B elimination by 2030.Funding: As per sources of funding.  相似文献   
77.
目的 探讨糖尿病前期的中医证型及证素分布特点。方法 检索中国知网、万方及维普三大数据库中收录的自建库以来有关糖尿病前期证型的临床研究文献,对中医证型进行规范整理,建立数据库,提取证素,运用数据挖掘技术中的关联分析、聚类分析探究证素分布规律。结果 共纳入10篇文献,总有效病例1620例,证型经规范处理后整理为18个,主要证型为脾虚痰湿证。共提取证素13个,主要病位证素为脾,主要病性证素为气虚、湿和痰,关联分析显示脾—湿支持度和置信度最高,聚类分析结果可得到3个聚类组。结论 糖尿病前期病位在脾,气虚、脾、痰、湿是常见证素,临床诊治糖尿病前期应注重从脾论治,需辨证施治。  相似文献   
78.
Background/purposePertussis incidence markedly decreased due to universal vaccination, but outbreaks had been noted worldwide in recent decade. This study was conducted to know the epidemiology of pertussis and its impact on infants in Taiwan.MethodsEpidemiologic parameters for confirmed pertussis cases were collected from the Taiwan Centers for Disease Control. The incidence of each age group over years was calculated using population data. We also did retrospective reviews of laboratory-confirmed pertussis cases in NTUH to analyze clinical characteristics and disease severity.ResultsA total of 668 confirmed pertussis cases were obtained from the Taiwan CDC open database between 2003 and 2017. There was higher incidence during the period 2009–2015, with a mean incidence of 0.27 cases per 100,000 population, about 2-fold increase compared with mean incidence of 0.12 cases per 100,000 population during the period 2003–2008. Infants accounted for the highest proportion of all cases (49.8%), with mean incidence of 16.1 cases per 100,000 people per year during 2009–2015, and a trend of increase was found from 2003 to 2015. In NTUH, a total of 17 laboratory-confirmed pertussis cases were diagnosed during 2012–2016, and 14 cases were young infants. Among them, 9 infants had been admitted to intensive care unit and 2 infant needed invasive ventilator support.ConclusionThere was a resurgence of pertussis during 2009–2015 and it had significant impact on infants. Young infants with pertussis may be severe and need intensive care, so preventive strategy may be advocated for them.  相似文献   
79.
肠易激综合征(IBS)是一种常见的功能性疾病,中医病名为"肠郁"。郭朋教授根据IBS生理、病理特点,以疏肝健脾法调和肝脾,辨证施治,取得良好疗效。文章从病因病机、辨证论治及经典案例介绍等几个方面对郭教授治疗IBS经验进行系统阐述,以期为中医药治疗IBS提供理论和方法学参考。  相似文献   
80.
经脉包括经(气)络和血(脉)络,清代周学海《读医随笔》将气络末端称为"气之细络",脉络末端称为"血之细络"。心之气络涵盖心脏起搏与传导系统等广泛调控机制,心之脉络涵盖冠状动脉循环系统,心之气络与脉络相互协调,营卫相偕而行,共同维持心脏正常功能。各种致病因素导致营卫异常而发为心律失常,基于脉络学说营卫理论"损其心者,调其营卫"(《难经·十四难》)治疗原则指导心律失常辨证论治,同时充分结合现代致病因素和致病特点,分别选用调节卫气营血之方药,标本兼治,以期为临床诊疗提供有益借鉴。  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