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   245227篇
  免费   22408篇
  国内免费   5454篇
耳鼻咽喉   3429篇
儿科学   5645篇
妇产科学   3895篇
基础医学   21422篇
口腔科学   7770篇
临床医学   23348篇
内科学   28769篇
皮肤病学   3251篇
神经病学   12398篇
特种医学   6297篇
外国民族医学   15篇
外科学   22724篇
综合类   39343篇
现状与发展   13篇
一般理论   25篇
预防医学   30125篇
眼科学   2467篇
药学   23647篇
  355篇
中国医学   28126篇
肿瘤学   10025篇
  2024年   805篇
  2023年   4868篇
  2022年   7780篇
  2021年   12172篇
  2020年   11721篇
  2019年   12894篇
  2018年   11547篇
  2017年   10239篇
  2016年   9380篇
  2015年   8721篇
  2014年   16915篇
  2013年   17347篇
  2012年   15331篇
  2011年   16330篇
  2010年   13011篇
  2009年   11427篇
  2008年   10669篇
  2007年   10548篇
  2006年   9015篇
  2005年   7677篇
  2004年   6294篇
  2003年   5498篇
  2002年   4311篇
  2001年   3629篇
  2000年   3167篇
  1999年   2587篇
  1998年   2122篇
  1997年   1882篇
  1996年   1574篇
  1995年   1444篇
  1994年   1316篇
  1993年   1175篇
  1992年   1086篇
  1991年   963篇
  1990年   842篇
  1989年   802篇
  1988年   734篇
  1987年   670篇
  1986年   615篇
  1985年   1883篇
  1984年   2125篇
  1983年   1337篇
  1982年   1763篇
  1981年   1222篇
  1980年   1046篇
  1979年   931篇
  1978年   761篇
  1977年   574篇
  1976年   717篇
  1975年   482篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
PurposeFew investigations have examined the production of single restorations using intraoral scanners (IOS). Data on full-arch scans are rare, and data regarding torsion within the entire arch are very sparsely reported. Therefore, the aim of this study was to examine the deviations of torsion and linear distances in full-arch scans of three IOS based on different scanning principles.MethodsA cobalt-chrome-molybdenum alloy master model (CCMM) with four hemispheres was fabricated by laser sintering. The CCMM was digitized using a laboratory scanner (ATOS-Core/GOM) and scanned with three IOS (Omnicam/Sirona(OC); True Definition/3M(TD); TriosII/Cara-Version/Kulzer(TR)). All scan data were exported in a standard STL-file format and were analyzed with GOM Inspect software (V7.5/GOM). Torsion between the right and left side of the arch and linear accuracy (trueness and precision) were evaluated. After normality was confirmed, all data were subjected to parametric statistical analyses.ResultsThe torsion ranged from 0.07 ± 0.03°(OC) to 0.29 ± 0.14°(TD). Pairwise comparisons showed significant differences between the OC and TD scanners and between the TR and TD scanners. The linear distances ranged from 6 ± 5 μm(OC) to 298 ± 317 μm(TD). Significant differences were observed among all investigated IOS (p = 0.05).ConclusionsAlthough the highest torsion was observed for the TD scanner, it is still not clear whether the differences between the IOS are related to the scanning principle or to the scanning algorithm. Due to the high clinical relevance of full-arch restorations, future studies should consider torsion. Regarding linear accuracy, no general difference related to the scanning principles of the IOSs was observed.  相似文献   
92.
93.
94.
95.
96.
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   
97.
目的本文主要研究和探讨护理干预对放疗科头颈部肿瘤放疗患者生活质量的影响。方法将我院2017年2月份至2018年10月份收治的100例头颈部肿瘤放疗患者作为本次研究的对象,在随机原则的指导下把100例患者分为对照组和实验组,每组患者的数量为50例。对照组患者给予常规护理,实验组患者实施护理干预,对两组患者的生活质量、睡眠质量、护理满意度和护理依从性等进行对比分析。结果在生活质量、睡眠质量、护理满意度和护理依从性等方面,组间进行对比分析,实验组都明显优于对照组,P<0.05差异具有统计学意义。结论对头颈部肿瘤放疗患者实施护理干预可以让患者的生活质量、睡眠质量、护理依从性以及护理满意度等都得到显著的改善,从而让患者以一种积极、乐观的心态接受放疗,这对于放疗效果的提高具有重要的作用。总之,这一护理模式应该在临床中进行推广和使用。  相似文献   
98.
99.
100.
《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   
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