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   13773篇
  免费   1251篇
  国内免费   398篇
耳鼻咽喉   92篇
儿科学   116篇
妇产科学   504篇
基础医学   831篇
口腔科学   317篇
临床医学   1920篇
内科学   692篇
皮肤病学   62篇
神经病学   317篇
特种医学   532篇
外科学   909篇
综合类   2764篇
一般理论   5篇
预防医学   2301篇
眼科学   124篇
药学   1899篇
  59篇
中国医学   1745篇
肿瘤学   233篇
  2024年   43篇
  2023年   344篇
  2022年   556篇
  2021年   760篇
  2020年   778篇
  2019年   527篇
  2018年   531篇
  2017年   616篇
  2016年   620篇
  2015年   574篇
  2014年   1182篇
  2013年   1477篇
  2012年   1105篇
  2011年   1086篇
  2010年   776篇
  2009年   672篇
  2008年   688篇
  2007年   595篇
  2006年   523篇
  2005年   392篇
  2004年   317篇
  2003年   261篇
  2002年   183篇
  2001年   156篇
  2000年   127篇
  1999年   86篇
  1998年   58篇
  1997年   63篇
  1996年   61篇
  1995年   53篇
  1994年   39篇
  1993年   22篇
  1992年   31篇
  1991年   17篇
  1990年   19篇
  1989年   13篇
  1988年   14篇
  1987年   13篇
  1986年   9篇
  1985年   6篇
  1984年   6篇
  1983年   5篇
  1982年   6篇
  1981年   2篇
  1980年   4篇
  1979年   1篇
  1978年   1篇
  1976年   1篇
  1974年   1篇
  1973年   2篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
目的:阐述动物智能在军事学的应用及意义。方法:以学术论文、新闻、报纸、智库报告等作为信息源,综合研究国外动物智能军事应用实例及内在关联,描述动物智能在未来战场应用场景。结果:动物智能军事应用主要是动物特殊能力的军事应用和动物智能的仿生武器应用。结论:动物部队、仿生作战部队和动物战术是未来战争不可忽视的重要组成部分,动物智能的隐匿、灵活、多变等特点正逐渐被广泛应用于战场。  相似文献   
2.
《Enfermería clínica》2022,32(3):171-183
IntroductionAgeing is a period of physical and psychological changes. Inactivity is one of the biggest problems among the older adult population increasing the risk of sarcopenia and chronic diseases. Physical activity is an effective intervention to improve health outcomes. In recent years, there has been an increase in the use of technology, with health technology tools (ICT) appearing as an intervention to increase physical activity and improve associated health problems.ObjectiveIn this review, we evaluated the effectiveness of health technology to increase physical activity and to improve cardiovascular parameters in older adults.MethodologyStudies with a great variety of health technology tools to increase physical activity levels, and that evaluated the effect of that increase on cardiovascular parameters were included by searching the main databases.ResultsEleven studies reporting the use of a variety of ICT tools were included in this review. Despite these differences, the effectiveness of health technology tool interventions has been demonstrated in increasing physical activity and reducing cardiovascular parameters.DiscussionThe lack of adherence of older adults to health technology would be a disadvantage, but it has been shown that younger older adults are more familiar with health technology tools and the number using them is increasing.ConclusionHealth technology tools show effectiveness in increasing physical activity in older adults and improving cardiovascular parameters.  相似文献   
3.
4.
《Value in health》2022,25(9):1480-1488
ObjectivesInvolvement of patients and medical professionals in assessment of relative effectiveness (relative effectiveness assessment) contributes to an efficient and effective health technology assessment (HTA) process and supports acceptance and implementation of the outcome. This study aimed to analyze stakeholder involvement in assessing relative effectiveness and how the parties involved value this collaboration.MethodsThis is a document analysis of all drug assessments completed in 2019 (20) by the public HTA agency of The Netherlands, enriched with semistructured interviews with employees of the HTA agency (18) and representatives of patient (5) and medical (11) associations involved in these assessments. Data were analyzed, coded, and categorized.ResultsIn almost half of the assessments, there was no coordination with the medical associations at the start of the relative effectiveness assessment and no patient associations involved in this phase. During the assessment procedure, patient and medical associations were always asked to comment on the draft report. Nevertheless, the strict 5-day deadline that the HTA agency uses as a response period often hampered a proper response and involvement. According to interviewees of the HTA agency, this leads to a great diversity in the substantive quality of their input. Patient and medical associations indicated that the HTA agency relies too much on “paper knowledge,” which leads to a (perceived) lack of alignment with clinical practice.ConclusionsThe limited involvement results in a lack of coordination and mutual trust. Optimizing involvement of patients and medical professionals in HTA practice requires effort from all parties involved. Procedural adjustments and better coordination, especially at the start of the assessment, would probably improve cooperation.  相似文献   
5.
生理电信号作为生物医学工程中的重要信号,其中蕴含了丰富的人体信息。该研究以生理电信号为主线,通过对其信号的学习、获取、分析、处理将生物医学工程的专业课串联起来,使学生将专业知识和实际仪器设计分析结合起来,能较为全面的掌握信号与系统方面的知识,加强学生的实际分析和解决医学问题的能力。  相似文献   
6.
7.
8.
BackgroundPeople living with multiple sclerosis (MS) experience impairments in gait and mobility, that are not fully captured with manually timed walking tests or rating scales administered during periodic clinical visits. We have developed a smartphone-based assessment of ambulation performance, the 5 U-Turn Test (5UTT), a quantitative self-administered test of U-turn ability while walking, for people with MS (PwMS).Research questionWhat is the test-retest reliability and concurrent validity of U-turn speed, an unsupervised self-assessment of gait and balance impairment, measured using a body-worn smartphone during the 5UTT?Methods76 PwMS and 25 healthy controls (HCs) participated in a cross-sectional non-randomised interventional feasibility study. The 5UTT was self-administered daily and the median U-turn speed, measured during a 14-day session, was compared against existing validated in-clinic measures of MS-related disability.ResultsU-turn speed, measured during a 14-day session from the 5UTT, demonstrated good-to-excellent test-retest reliability in PwMS alone and combined with HCs (intraclass correlation coefficient [ICC] = 0.87 [95 % CI: 0.80–0.92]) and moderate-to-excellent reliability in HCs alone (ICC = 0.88 [95 % CI: 0.69–0.96]). U-turn speed was significantly correlated with in-clinic measures of walking speed, physical fatigue, ambulation impairment, overall MS-related disability and patients’ self-perception of quality of life, at baseline, Week 12 and Week 24. The minimal detectable change of the U-turn speed from the 5UTT was low (19.42 %) in PwMS and indicates a good precision of this measurement tool when compared with conventional in-clinic measures of walking performance.SignificanceThe frequent self-assessment of turn speed, as an outcome measure from a smartphone-based U-turn test, may represent an ecologically valid digital solution to remotely and reliably monitor gait and balance impairment in a home environment during MS clinical trials and practice.  相似文献   
9.
目的 基于网络药理学和分子对接技术探究黄芪-赤芍配伍对治疗慢性阻塞性肺疾病(chronic obstructive pulmonary disease,COPD)的作用机制。方法 利用TCMSP,Pharmmaper数据库,筛选黄芪-赤芍治疗COPD的活性成分和潜在靶点;结合Genecards数据库挖掘的COPD相关靶点,对黄芪-赤芍药对与COPD靶点进行PPI网络构建,交互处理得到黄芪-赤芍药对治疗COPD的关键靶点,并进行GO分析和KEGG通路富集分析;并采用分子对接技术将主要活性成分与TNF-α(肿瘤坏死因子),IL-6(白细胞介素6)等进行分子对接;最后利用A549炎症细胞与人脐静脉内皮细胞缺氧损伤模型进行体外细胞实验对结果加以验证。结果 黄芪-赤芍药对中44个有效成分作用于COPD,核心成分为:槲皮素、山奈酚、丁子香萜、芍药苷、(2R,3R)-4-methoxyl-distylin、二氢异黄酮;黄芪-赤芍药对通过IL6、PTGS2、TNF等113个靶蛋白,调控Ras、PI3KAkt、IL-17等多条信号通路治疗COPD,且分子对接结果显示槲皮素、山奈酚、丁子香萜、芍药苷与IL-6、PTGS2、TNF大分子蛋白有良好的结合性,体外细胞试验证实,槲皮素与山奈酚均能减少IL-8,MMP-9炎症因子的分泌,具有不同程度的抗炎效果;芍药苷有明显的扩血管、抗血栓之效。结论 黄芪-赤芍药对治疗COPD具有多成分、多靶点、多通路、整体调节的作用特点。初步揭示了黄芪-赤芍药对通过抑制炎症反应、调节上皮细胞生长增强保护屏障等预测出黄芪-赤芍药对治疗COPD的潜在作用机制,以期为其活性成分的药效物质基础提供理论研究和思路。  相似文献   
10.
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