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   103007篇
  免费   7412篇
  国内免费   2528篇
耳鼻咽喉   558篇
儿科学   1290篇
妇产科学   929篇
基础医学   9353篇
口腔科学   1370篇
临床医学   10713篇
内科学   8955篇
皮肤病学   647篇
神经病学   9375篇
特种医学   2803篇
外国民族医学   2篇
外科学   6149篇
综合类   20550篇
现状与发展   8篇
一般理论   38篇
预防医学   23112篇
眼科学   915篇
药学   9110篇
  359篇
中国医学   4185篇
肿瘤学   2526篇
  2024年   192篇
  2023年   1461篇
  2022年   2307篇
  2021年   4048篇
  2020年   4230篇
  2019年   2991篇
  2018年   2902篇
  2017年   2908篇
  2016年   3161篇
  2015年   3110篇
  2014年   6921篇
  2013年   7486篇
  2012年   6697篇
  2011年   7340篇
  2010年   5947篇
  2009年   5378篇
  2008年   5768篇
  2007年   5407篇
  2006年   4838篇
  2005年   4006篇
  2004年   3305篇
  2003年   2812篇
  2002年   2184篇
  2001年   1877篇
  2000年   1572篇
  1999年   1286篇
  1998年   1224篇
  1997年   1170篇
  1996年   989篇
  1995年   935篇
  1994年   839篇
  1993年   664篇
  1992年   638篇
  1991年   665篇
  1990年   556篇
  1989年   491篇
  1988年   504篇
  1987年   456篇
  1986年   452篇
  1985年   554篇
  1984年   486篇
  1983年   319篇
  1982年   347篇
  1981年   298篇
  1980年   291篇
  1979年   178篇
  1978年   190篇
  1977年   177篇
  1976年   144篇
  1975年   74篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
31.
Advancement in microelectromechanical system has facilitated the microfabrication of polymeric substrates and the development of the novel class of controlled drug delivery devices. These vehicles have specifically tailored three dimensional physical and chemical features which together, provide the capacity to target cell, stimulate unidirectional controlled release of therapeutics and augment permeation across the barriers. Apart from drug delivery devices microfabrication technology’s offer exciting prospects to generate biomimetic gastrointestinal tract models. BioMEMS are capable of analysing biochemical liquid sample like solution of metabolites, macromolecules, proteins, nucleic acid, cells and viruses. This review summarized multidisciplinary application of biomedical microelectromechanical systems in drug delivery and its potential in analytical procedures.  相似文献   
32.
[目的] 系统评价八段锦治疗神经根型颈椎病的临床疗效。[方法] 计算机检索中国知网数据库(CNKI)、维普资讯中文科技期刊数据库(VIP)、万方数据库(Wan-fang)、中国生物医学文献数据库(SinoMed)、Web of science、Clinical Trials gov、Pubmed、EMBASE、CENTRAL、Cochrane Library,查找出八段锦治疗神经根型颈椎病的随机对照试验(RCT),检索时限均从建库至2019年7月1日。两名研究者按照纳入与排除标准独立进行文献筛选、资料提取和偏倚风险评估,应用RevMan 5.3软件对最后纳入的研究进行Meta分析。[结果] 最终纳入10个RCT,共843例患者。Meta分析结果显示:八段锦+常规治疗与常规治疗比较,其临床疗效的总有效率差异具有统计学意义[OR=4.19,95% CI(2.42,7.26),P<0.000 01];八段锦+常规治疗与常规治疗+颈部“米”字操比较,其临床疗效的总有效率差异具有统计学意义[OR=3.41,95% CI(1.56,7.46),P=0.002];八段锦+常规治疗与常规治疗比较,其疼痛视觉模拟评分法(VAS)评分差异具有统计学意义[MD=-1.90,95% CI(-1.97,-1.83),P<0.000 01]。[结论] 基于现有的研究,该系统评价显示,与常规治疗相比,八段锦+常规治疗在临床疗效总有效率、VAS评分方面有一定的治疗优势。与常规治疗+颈部“米”字操比较,八段锦+常规治疗在临床疗效的总有效率方面有一定的治疗优势。但由于纳入研究的质量不高,仍需要大样本、多中心、随机、双盲试验及试验参照CONSORT标准和STRICTA声明进行RCT研究。  相似文献   
33.
ABSTRACT

Introduction

Type 1 diabetes mellitus (T1DM) is a chronic, autoimmune disease that is characterized by total absence of insulin production. Hypertension is a common comorbidity in T1DM with complex pathophysiology, while it is also a well-recognized risk factor for the development of cardiovascular disease (CVD), as well as other microvascular diabetic complications.  相似文献   
34.
《Clinical neurophysiology》2021,132(12):3104-3115
ObjectiveWe aimed to establish an objective neurophysiological test protocol that can be used to assess the somatosensory nervous system.MethodsIn order to assess most fiber subtypes of the somatosensory nervous system, repetitive stimuli of seven different modalities (touch, vibration, pinprick, cold, contact heat, laser, and warmth) were synchronized with the electroencephalogram (EEG) and applied on the cheek and dorsum of the hand and dorsum of the foot in 21 healthy subjects and three polyneuropathy (PNP) patients. Latencies and amplitudes of the modalities were assessed and compared. Patients received quantitative sensory testing (QST) as reference.ResultsWe found reproducible evoked potentials recordings for touch, vibration, pinprick, contact-heat, and laser stimuli. The recording of warm-evoked potentials was challenging in young healthy subjects and not applicable in patients. Latencies were shortest within Aβ-fiber-mediated signals and longest within C-fibers. The test protocol detected function loss within the Aβ-fiber and Aδ-fiber-range in PNP patients. This function loss corresponded with QST findings.ConclusionIn this pilot study, we developed a neurophysiological test protocol that can specifically assess most of the somatosensory modalities. Despite technical challenges, initial patient data appear promising regarding a possible future clinical application.SignificanceEstablished and custom-made stimulators were combined to assess different fiber subtypes of the somatosensory nervous system using modality-specific evoked potentials.  相似文献   
35.
目的探讨案例教学法在消化内科见习课的教学效果和体会。方法选取2017年10月—2017年12月在消化内科进行见习课的2015级39-40班护理本科学生44例(全部为女生),抓阄分成对照组(22人)和试验组(22人),对照组给予传统的带教方法,试验组给予案例教学法教学,比较两组护生在理论、技能、综合能力和对带教满意度方面有无差异。两组学生在性别、年龄、专业前的课程成绩比较,差异无统计学意义(均P>0.05)。结果观察组在理论考核成绩、操作考核成绩、教学满意度等方面均高于对照组。结论案例教学法能提高护理教学的教学效果,增加学生的理论、操作能力,提高护理临床思维能力,提升学生的学习主动性和积极性。  相似文献   
36.
放疗记录与验证系统(RVS)是一套用于防止医用电子加速器等放疗设备治疗参数设置错误,并且记录所有放疗阶段执行参数的医用计算机软件控制系统。为确保患者的治疗安全,必须对记录与验证系统采取必要的质量控制措施。本指南内容涉及:RVS安装和参数设定过程中的质量控制;RVS的验收测试;RVS在临床使用过程中的持续质量控制;使用RVS过程中的典型错误类型;执行RVS验收测试的具体测试例。  相似文献   
37.
Patients with mechanic ankle instability experience increased tibiotalar and subtalar joint laxity. However, in vivo joint kinematics in functional ankle instability (FAI) patients and lateral ankle sprain (LAS) copers, especially during dynamic activities, are poorly understood. Ten FAI patients, 10 LAS copers, and 10 healthy controls were included in this study. A dual fluoroscopic imaging system was used to analyze the tibiotalar and subtalar joint kinematics during stair descent. Five key poses of stair descent were analyzed. Kinematic data from six degrees of freedom were calculated utilizing a solid modeling software. The range of motion and joint positions in each degree of freedom were compared among the three groups. The tibiotalar joints of FAI patients and LAS copers were significantly more inverted than those of healthy controls during the foot strike (p = 0.016, = 0.264). The subtalar joints of FAI patients were significantly more anteriorly translated (pose 2, p = 0.003, = 0.352; pose 3, p < 0.001, = 0.454; pose 4, p = 0.004, = 0.334), inverted (pose 4, p = 0.027, = 0.234; pose 5,p = 0.034, = 0.221), and externally rotated (pose 4, p = 0.037, = 0.217; pose 5; p = 0.004, = 0.331) than those of healthy controls during the mid‐stance and the heel off. The FAI patients showed excessive tibiotalar inversion and subtalar joint hypermobility during stair descent. Meanwhile, the LAS copers maintained subtalar joint stability, and only showed excessive tibiotalar inversion in foot strike. These data provide insight into the mechanisms behind the development of FAI after initial LAS. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1860–1867, 2019  相似文献   
38.
Problem: The Leaders in Indigenous Medical Education (LIME) Network aims to improve the quality and effectiveness of Indigenous health in medical education as well as best practice in the recruitment, retention, and graduation of Indigenous medical students. Intervention: In this article we explore the utility of Etienne Wenger's “communities of practice” (CoP) concept in providing a theoretical framework to better understand the LIME Network as a form of social infrastructure to further knowledge and innovation in this important area of health care education reform. Context: The Network operates across all medical schools in Australia and New Zealand. Outcome: Utilizing a model of evaluation of communities of practice developed by Fung-Kee-Fung et al., we seek to analyze the outcomes of the LIME Network as a CoP and assess its approach and contribution to improving the implementation of Indigenous health in the medical curriculum and the graduation of Indigenous medical students. Lessons Learned: By reflecting on the Network through a community of practice lens, this article highlights the synthesis between the LIME Network and Wenger's theory and provides a framework with which to measure Network outputs. It also posits an opportunity to better capture the impact of Network activities into the future to ensure that it remains a relevant and sustainable entity.  相似文献   
39.
Pulmonary hypertension of the newborn (PHN) constitutes a critical condition with severe cardiovascular and neurological consequences. One of its main causes is hypoxia during gestation, and thus, it is a public health concern in populations living above 2500 m. Although some mechanisms are recognized, the pathophysiological facts that lead to PHN are not fully understood, which explains the lack of an effective treatment. Oxidative stress is one of the proposed mechanisms inducing pulmonary vascular dysfunction and PHN. Therefore, we assessed whether melatonin, a potent antioxidant, improves pulmonary vascular function. Twelve newborn sheep were gestated, born, and raised at 3600 meters. At 3 days old, lambs were catheterized and daily cardiovascular measurements were recorded. Lambs were divided into two groups, one received daily vehicle as control and another received daily melatonin (1 mg/kg/d), for 8 days. At 11 days old, lung tissue and small pulmonary arteries (SPA) were collected. Melatonin decreased pulmonary pressure and resistance for the first 3 days of treatment. Further, melatonin significantly improved the vasodilator function of SPA, enhancing the endothelial‐ and muscular‐dependent pathways. This was associated with an enhanced nitric oxide‐dependent and nitric oxide independent vasodilator components and with increased nitric oxide bioavailability in lung tissue. Further, melatonin reduced the pulmonary oxidative stress markers and increased enzymatic and nonenzymatic antioxidant capacity. Finally, these effects were associated with an increase of lumen diameter and a mild decrease in the wall of the pulmonary arteries. These outcomes support the use of melatonin as an adjuvant in the treatment for PHN.  相似文献   
40.
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