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   237921篇
  免费   20036篇
  国内免费   7240篇
耳鼻咽喉   1316篇
儿科学   8120篇
妇产科学   2041篇
基础医学   21358篇
口腔科学   3728篇
临床医学   26140篇
内科学   56070篇
皮肤病学   2816篇
神经病学   33798篇
特种医学   6397篇
外国民族医学   4篇
外科学   17302篇
综合类   32244篇
现状与发展   33篇
一般理论   13篇
预防医学   18559篇
眼科学   2386篇
药学   17013篇
  213篇
中国医学   11285篇
肿瘤学   4361篇
  2024年   268篇
  2023年   4824篇
  2022年   6277篇
  2021年   11782篇
  2020年   12024篇
  2019年   9325篇
  2018年   9207篇
  2017年   9231篇
  2016年   9589篇
  2015年   9165篇
  2014年   17046篇
  2013年   19206篇
  2012年   14066篇
  2011年   15122篇
  2010年   12049篇
  2009年   11596篇
  2008年   11566篇
  2007年   11195篇
  2006年   9951篇
  2005年   8244篇
  2004年   6964篇
  2003年   6038篇
  2002年   5098篇
  2001年   4348篇
  2000年   3560篇
  1999年   2934篇
  1998年   2609篇
  1997年   2276篇
  1996年   1980篇
  1995年   2093篇
  1994年   1953篇
  1993年   1654篇
  1992年   1606篇
  1991年   1396篇
  1990年   1112篇
  1989年   975篇
  1988年   916篇
  1987年   846篇
  1986年   728篇
  1985年   855篇
  1984年   701篇
  1983年   444篇
  1982年   507篇
  1981年   427篇
  1980年   325篇
  1979年   283篇
  1978年   207篇
  1977年   194篇
  1976年   156篇
  1975年   68篇
排序方式: 共有10000条查询结果,搜索用时 281 毫秒
51.
《Vaccine》2022,40(43):6201-6205
Systemic immunosuppressive therapy (IS) renders patients with inflammatory bowel disease (IBD) vulnerable to fulminant hepatitis B virus (HBV) infection. Seroprotection against HBV through a full vaccination scheme is preferably obtained before IS is initiated, but often conflicts with the clinical need to initiate therapy rapidly. Consequently, the vast majority of patients will use IS during booster vaccinations. In this retrospective cohort study, we examined the serological response after a modified vaccination schedule which includes an initial double dose of Fendrix in patients with IBD and compared the results with the serological responses of patients with IBD who received the standard schedule. Seroprotection rates were 86.2 % and 88.9 % in the modified and standard schedule groups respectively. One-third of patients obtained seroprotection after only one double dose vaccine. A double dose may be considered in patients with IBD at high short-term risk of HBV infection when a rapid protective response is warranted.  相似文献   
52.
BackgroundIt is unknown if improvements in gait velocity following an aerobic cycling intervention are accompanied by improved gait biomechanics in individuals with Parkinson’s disease (PD) or if gait abnormalities are exaggerated in response to increased velocity.Research questionCan an 8-week aerobic cycling intervention elicit improvements in locomotor function in individuals with mild to moderate PD?MethodsA secondary analysis of data from a randomized clinical trial was conducted in individuals with mild to moderate idiopathic PD (N = 28). Participants were randomized to an aerobic cycling intervention (PDex, N = 14) consisting of 24 sessions at a targeted aerobic intensity of 60–80% of heart rate reserve or to a no intervention control group (PDcontrol, N = 14). Change in comfortable walking speed in addition to gait kinematics, kinetics, and spatiotemporal variables using motion capture were obtained at baseline and end of treatment (EOT).ResultsThe PDex group made significantly greater improvements in the primary outcome, change in comfortable gait velocity, from 0.86 ± 0.24 m/s at baseline to 1.00 ± 0.23 m/s at EOT compared to the PDcontrol group who declined from 0.91 ± 0.23 m/s at baseline to 0.80 ± 0.29 at EOT (P = 0.002). Improvements in gait velocity for the PDex group were accompanied by improvements in gait kinematics, kinetics, and spatiotemporal parameters, while the PDcontrol group demonstrated slight worsening in all gait parameters over the 8-week period.SignificanceThe 8-week moderate- to high-intensity cycling intervention elicited significantly greater improvements in gait velocity compared to the PDcontrol group. Increased gait velocity was accompanied by normalization of gait biomechanics, rather than an exaggeration of existing gait deviations. Aerobic cycling may be a viable treatment approach to improve gait velocity and gait biomechanics in individuals with mild to moderate PD and may mitigate declines in mobility.  相似文献   
53.
社区动脉粥样硬化风险(ARIC)研究是1987年由美国心、肺和血液研究所资助的关注非洲裔美国人心血管健康的最大研究。旨在调查心脏病的危险因素以及心血管疾病与认知之间的联系。ARIC研究的许多发现加深了对动脉粥样硬化性心血管病病因的了解,在心血管病预防领域做出了重大贡献,证明了以人群为基础的研究对改善健康和预防疾病的重要性。主要概述ARIC研究的起源、目的、研究设计、对心血管医学的贡献以及未来的发展方向。  相似文献   
54.
目的 基于数据非依赖性采集的定量蛋白质组学技术(data independent acquisition,DIA)对稳定性冠心病血瘀证患者的血浆蛋白质进行研究分析,初步探索冠心病血瘀证的关键生物学过程与核心靶点。方法 选择中国中医科学院广安门医院心血管科收治的5例稳定性冠心病患者作为疾病观察组,同时选取健康成人5人作为对照组,采用DIA蛋白质组学技术对受试者的血浆进行检测,确定蛋白质表达量后进行差异蛋白质表达分析、GO富集分析、KEGG信号通路图查询和蛋白质互作网络分析。结果 在差异倍数为1.5倍时,疾病观察组相比于健康对照组,共鉴定到22个蛋白质下调,9个蛋白质上调。进一步的生物信息学分析表明,冠心病血瘀证的生物学过程与补体参与的慢性炎症反应有关,关键信号通路是补体与凝血级联反应的信号通路,核心蛋白质为C反应蛋白、转甲状腺素蛋白、补体因子H、维生素D结合蛋白等。结论 冠心病血瘀证的生物学过程与补体参与的慢性炎症反应有关。  相似文献   
55.
56.
57.
58.
IntroductionDetailed data on clinical characteristics in children with the omicron strain of SARS-COV-2 are limited.MethodsWe conducted a retrospective observational study of children with COVID-19 at the National Center for Child Health and Development to evaluate the clinical manifestations during and before the emergence of the omicron variant. Only symptomatic patients without underlying diseases were included. Participants were divided into two temporal groups: the “omicron era” (1/2022–2/2022) and the “pre-omicron era,” where the delta variant predominated (7/2021–11/2021). The patients were subclassified into an older vaccine-eligible group (aged 12–17 years), a younger vaccine-eligible group (aged 5–11 years), and a vaccine-ineligible group (aged 0–4 years).ResultsWe compared 113 patients in the omicron era with 106 in the pre-omicron era. Most patients in both eras had non-severe disease, and no patients required mechanical ventilation or died. Among patients aged 0–4 years, sore throat and hoarseness were more common during the omicron era than the pre-omicron era (11.1% vs. 0.0% and 11.1% vs. 1.5%, respectively). Croup syndrome was diagnosed in all patients with hoarseness. Among patients aged 5–11 years, vomiting was more frequent during the omicron era (47.2%) than during the pre-omicron era (21.7%). Cough and rhinorrhea were less common during the omicron era in patients aged 0–4 and 5–11 years, respectively, than during the pre-omicron era.ConclusionsIn children with COVID-19, clinical manifestations differed between the omicron and pre-omicron eras. In the Omicron era, croup syndrome was more frequent in vaccine-ineligible children.  相似文献   
59.
60.
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