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   6771篇
  免费   269篇
  国内免费   119篇
耳鼻咽喉   28篇
儿科学   71篇
妇产科学   7篇
基础医学   659篇
口腔科学   286篇
临床医学   380篇
内科学   152篇
皮肤病学   31篇
神经病学   164篇
特种医学   338篇
外科学   2402篇
综合类   1410篇
预防医学   342篇
眼科学   25篇
药学   615篇
  13篇
中国医学   207篇
肿瘤学   29篇
  2024年   10篇
  2023年   79篇
  2022年   137篇
  2021年   218篇
  2020年   253篇
  2019年   180篇
  2018年   157篇
  2017年   200篇
  2016年   292篇
  2015年   253篇
  2014年   601篇
  2013年   504篇
  2012年   587篇
  2011年   608篇
  2010年   477篇
  2009年   377篇
  2008年   306篇
  2007年   279篇
  2006年   283篇
  2005年   221篇
  2004年   186篇
  2003年   132篇
  2002年   109篇
  2001年   92篇
  2000年   75篇
  1999年   56篇
  1998年   38篇
  1997年   47篇
  1996年   43篇
  1995年   38篇
  1994年   34篇
  1993年   32篇
  1992年   28篇
  1991年   26篇
  1990年   19篇
  1989年   17篇
  1988年   31篇
  1987年   22篇
  1986年   15篇
  1985年   16篇
  1984年   13篇
  1983年   15篇
  1982年   11篇
  1981年   12篇
  1980年   3篇
  1979年   5篇
  1978年   6篇
  1977年   6篇
  1976年   2篇
  1973年   4篇
排序方式: 共有7159条查询结果,搜索用时 15 毫秒
11.
12.
13.
BackgroundMeasuring dynamic vertical ground reaction force allows for assessment of important clinical and physical capacity factors such as weight bearing asymmetry, force distribution, and rate of force development. However, current technologies for accurately assessing ground reaction force are typically expensive.Research QuestionThe aim of this study was to examine the validity and reliability of obtaining static and dynamic ground reaction force data from low-cost modified digital bathroom scales.MethodsFour modified bathroom scales, two units each of two different brands, were examined. Repeated mechanical loading trials were performed with known loads ranging from 0.01 to 65 kg, with acquired data compared against the known loading to calculate accuracy, hysteresis, and non-linearity. Dynamic trials consisting of 5 times sit-to-stand and weight-shifting were performed by 32 adults. Absolute and relative agreement intraclass correlation coefficient, and Pearson’s and Spearman’s correlations were performed to determine validity and reliability for the mechanical tests. Bland-Altmann plots were created for each comparison. Mean absolute error (MAE) and unbiased cross-correlation were performed on the dynamic data, comparing the calibrated data to the known values from a Bertec force platform.ResultsHysteresis and non-linearity were excellent (<0.2 % full-scale), and mechanical test results showed excellent reliability and validity. Cross-correlation results for the dynamic data were excellent, however MAE for the more rapid sit-to-stand task was higher than the slower weight-shifting test. This may have been due to the low default sampling rate for the lowest noise setting of the HX711 amplifier (10 Hz).SignificanceIn summary, our results suggest that digital bathroom scales can be easily and inexpensively modified to obtain accurate vertical ground reaction force data, with sensitivity to detect changes of as little as 0.01 kg.  相似文献   
14.
目的针对锁骨远端粉碎性骨折患者采用不同的内固定治疗方案进行临床治疗,分析其临床治疗效果。方法选取本院2016年8月—2018年7月收治的锁骨远端粉碎性骨折患者40例作为研究对象,按照随机数字表法分成两组,试验组20例,对照组20例。试验组患者采用锁骨远端锁定钢板内固定治疗方案,对照组患者采用锁骨钩钢板内固定治疗方案,对比两组患者的手术时间、术中出血量、愈合时间、并发症发生情况。结果研究结果表明,试验组患者的手术时间和术中出血量对比对照组差异没有统计学意义(P>0.05);试验组患者的愈合时间短于对照组,并发症发生率低于对照组,对比差异不具有统计学意义(P>0.05)。结论对于锁骨远端粉碎性骨折患者的治疗,采用锁骨远端锁定钢板内固定治疗方案能够有效缩短愈合时间,降低并发症发生率,促进患者快速恢复。  相似文献   
15.
BackgroundAcetabular fractures in the elderly frequently involve segmental quadrilateral plate injury, yet no consensus exists on how to best control the femoral head medial displacement. Quadrilateral surface plates (QSP) were developed to help buttress these challenging fractures. The study aims to 1) Determine the prevalence of segmental quadrilateral plate fractures (SQPF) in elderly patients; and 2) Assess if utilization of a QSP is associated with improved acetabulum fracture reduction and outcome.MethodsThis was a retrospective study conducted at a level-1 trauma centre. . All patients over 60-years that sustained an acetabular fracture between 2007 and 2019 were reviewed. Pre-operative pelvic radiographs and CT imaging were reviewed for 96 patients, to assess for SQPF. From the 96 patients reviewed, over one third of patients (n = 40, 41.6%) sustained a SQPF. Patients that had an acute-THA (n = 7) were excluded as were patients that underwent an ORIF but did not have a QSP or an anterior column buttress plate (n = 3). The remaining 30 formed the study’s cohort. We assessed the ability to achieve and maintain reduction in this elderly population, and compared outcomes using traditional anterior column buttress plates (ilioingual or intra-pelvic approach) versus an intra-pelvic pre-contoured buttress suprapectineal plate (QSP). Outcome measures included: fracture reduction using the Matta classification (desirable: anatomical/imperfect and poor), re-operations, conversion to THA and Oxford Hip Score (OHS) (for the preserved hips).ResultsTen patients had an ORIF with utilization of a QSP (QSP-group), and 20 had an ORIF but did not have the QSP (non-QSP-group). There was no difference in patient demographics between groups. Fracture patterns were also similar (p = 0.6). Postoperative fracture reduction was desirable (anatomical/imperfect) in 17 patients and poor in 13. Improved ability to achieve a desirable reduction was seen in the QSP-group (p = 0.02). Conversion to THA was significantly lower in patients that had a desirable fracture reduction (appropriate: 3/17; poor: 7/13). No patients in the QSP-group have required a THA to-date, compared to 10/20 patients in the non-QSP-group (p = 0.01). The mean time to THA was 1.6 ± 2.1 year. There was no difference in OHS between the two groups (34.4 ± 10.3).ConclusionElderly acetabulum fractures have a high incidence (approaching 40%) of segmental QPF. Desirable (anatomical/imperfect) fracture reduction was associated with improved outcome. The use of a QSP was associated with improved ability to achieve an appropriate reduction. A QSP should be considered as they are both reliable and reproducible with a significantly improved fracture reduction and lower conversion to THA.  相似文献   
16.
骨质疏松性骨折是老年人中最常见的骨骼系统疾病之一,具有发病率高、致残率高、致死率高和医疗支出大等特点。由于患者的骨质量差,粉碎性骨折多见,内固定治疗稳定性差,卧床时间较长,再骨折发生率高,因而,骨质疏松性骨折的手术治疗亦面临着诸多挑战。本文对近年来骨质疏松性骨折手术治疗的原则和技术进行回顾和总结。  相似文献   
17.
《Injury》2019,50(6):1166-1174
IntroductionThe purpose of this study was to evaluate the feasibility of the anteromedial minimally invasive plate osteosynthesis (MIPO) approach for distal third humeral shaft fractures and identify neurovascular structures at risk with this approach.MethodsTwenty cadaveric arms were fixed with 12-hole precontoured narrow locking compression plates (LCP) with the anteromedial approach using MIPO technique. The proximal approach was done between the biceps and deltoid muscle directly to the bone. The distal approach involved elevating the brachialis from medial intermuscular septum. The plate was inserted beneath the brachialis tunnel from distal to proximal. Three locking screws were fixed at each end through incisions and the rest of screws were inserted percutaneously. The arms were then dissected to identify damage to or direct contact between the screws and brachial artery (BA), median nerve (MN), musculocutaneous nerve (MCN), and radial nerve (RN). The distances from the screws to structures at risk, humeral length, and length of three distal screws in mediolateral (ML) direction were measured.ResultsThe average humeral length was 28.97 cm. The average danger zone for the BA and MN were 20.47%–62.66% of the humeral length from the lateral epicondyle, and 20.47%-75.02% for the MCN. The ulnar nerve was not endangered by this approach as it lies posteromedially to the humerus. The danger zone for the RN averaged 27.07%–43.74%, and the most dangerous screw that either penetrated or touched the nerve was at the fifth hole, which lay at 33.14% of the humeral length. The average length of three distal screws in ML direction were 41.4, 25.0 and 22.5 mm.ConclusionsThe anteromedial MIPO approach can be performed through the internervous plane beneath the brachialis muscle without exposing any nerves or causing any muscle splitting with a 12-hole plate. Both proximal and distal screw insertion must be done with direct exposure. Insertion of percutaneous screws in the middle part of the plate between the two incisions is not possible. This approach could be an alternative for extra-articular distal third humeral shaft fractures which provides less invasive surgical dissection, allows the use of longer distal screws, and achieves better cosmesis.  相似文献   
18.
19.
20.
文题释义:肱骨近端骨折:肱骨近端包括肱骨头及大结节、小结节,中老年人骨质疏松及低能量损伤可导致肱骨近端骨折。 同种异体腓骨:取自于人体异体,经过加工处理,去除其免疫原性,保留其骨性结构,可用于移植修复骨缺损,起到支撑作用。 背景:肱骨近端骨折是临床常见骨折,但对肱骨近端内侧柱缺乏支撑的骨折目前仍是治疗难点,并发症常见,失败率较高。 目的:比较解剖锁定钢板联合同种异体腓骨与单纯解剖锁定钢板治疗肱骨近端骨折的疗效。 方法:使用计算机检索PubMed、Embase、Cochrane Library、Google Scholar、中国知网、万方、维普数据库,检索时间均从建库到2020年2月。检索国内外关于对比研究解剖锁定钢板联合同种异体腓骨与单纯解剖锁定钢板治疗肱骨近端骨折疗效的文献。2名研究员根据纳入和排除标准分别独立筛选文献,提取数据,评估文献中的偏倚风险。纳入12篇相关文献使用RevMan 5.2软件将以下指标进行Meta分析,包括影像学数据、功能评分和并发症。结果与结论:①通过文献检索、根据纳入和排除标准,12篇文献纳入研究,其中11篇为回顾性队列研究,1篇为随机对照研究;纳入研究文献质量高,但GRADE证据质量级别较低。②共纳入958例患者,其中解剖锁定钢板联合同种异体腓骨组411例,单纯解剖锁定钢板组547例;③Meta分析结果显示,解剖锁定钢板联合同种异体腓骨组术后1年肱骨头高度差值(MD=-2.40,95%CI:-2.49至-2.31)、颈干角差值(MD= -6.14,95%CI:-6.62至-5.67)、目测类比评分(MD=-0.22,95%CI:-0.35至-0.08)、肩关节功能评分(MD=4.12,95%CI:2.18-6.06),上肢伤残评分(MD=-10.32,95%CI:-13.44至-7.19)、术后2年的目测类比评分(MD=-0.37,95%CI:-0.55至-0.19)、肩关节功能评分(MD=5.07,95%CI:2.86-7.27)、总体并发症(OR=0.31,95%CI:0.20-0.48)及肱骨头螺钉切出(OR=0.25,95%CI:0.11-0.55)均明显优于单纯解剖锁定钢板组(P < 0.05),肱骨头坏死(OR=0.94,95%CI:0.47-1.88),两组间差异无显著性意义(P > 0.05);④因此,较弱的证据提示,肱骨近端解剖锁定钢板联合同种异体腓骨治疗肱骨近端骨折的短期疗效优于解剖锁定钢板,可减少并发症的发生,促进功能恢复。ORCID: 0000-0002-8486-3932(阳运康) 中国组织工程研究杂志出版内容重点:人工关节;骨植入物;脊柱;骨折;内固定;数字化骨科;组织工程  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