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Sharp upper bounds for the adjacency and the signless Laplacian spectral radius of graphs 预览
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作者 WU Xian-zhang LIU Jian-ping 《高校应用数学学报:英文版(B辑)》 SCIE CSCD 2019年第1期100-112,共13页
Let G be a simple graph with n vertices and m edges.In this paper,we present some new upper bounds for the adjacency and the signless Laplacian spectral radius of graphs in which every pair of adjacent vertices has at... Let G be a simple graph with n vertices and m edges.In this paper,we present some new upper bounds for the adjacency and the signless Laplacian spectral radius of graphs in which every pair of adjacent vertices has at least one common adjacent vertex.Our results improve some known upper bounds.The main tool we use here is the Lagrange identity. 展开更多
关键词 graph SPECTRAL RADIUS signless LAPLACIAN SPECTRAL RADIUS upper bound
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肘关节常见骨折的相关问题探讨 预览
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作者 公茂琪 蒋继乐 蒋协远 《中国骨伤》 CAS CSCD 2019年第4期293-295,共3页
肘关节骨折是临床常见的损伤,但因肘关节自身的结构特点,术后并发症较高,特别是处理不当时容易发生肘关节僵硬,给患者生活带来很大困难。尽管近几年肘关节治疗的热点集中在肘关节复杂骨折脱位和肘关节创伤性不稳定等方面,但就发生率而言... 肘关节骨折是临床常见的损伤,但因肘关节自身的结构特点,术后并发症较高,特别是处理不当时容易发生肘关节僵硬,给患者生活带来很大困难。尽管近几年肘关节治疗的热点集中在肘关节复杂骨折脱位和肘关节创伤性不稳定等方面,但就发生率而言,肱骨髁间骨折、尺骨鹰嘴骨折和桡骨头骨折仍是最多见的几种损伤,而且这些常见骨折处理不当发生的并发症很多,值得广大的创伤骨科医生细化治疗以减少并发症,使患者获得更好的功能。其中肱骨远端骨折的治疗相对而言更复杂,并发症也更高。来自瑞典的全国性调查发现,肘部损伤中的肱骨远端骨折发病率约为8.3/100000[1],并随着年龄的增加而升高,其中老年女性最为常见。 展开更多
关键词 肘关节 肱骨 尺骨鹰嘴 桡骨 骨折
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阶梯性康复训练对手法整复夹板固定桡骨远端骨折患者腕关节功能恢复的影响 预览
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作者 胡晓龙 《大医生》 2019年第16期52-53,共2页
目的对桡骨远端骨折患者进行手法整复夹板固定,并进行阶梯性康复训练,分析其应用效果。方法选取2018年1月至12月在成都军区八一骨科医院治疗的44例桡骨远端骨折患者,所有患者均采取手法整复夹板固定方案治疗,将其分为两组,各22例。对照... 目的对桡骨远端骨折患者进行手法整复夹板固定,并进行阶梯性康复训练,分析其应用效果。方法选取2018年1月至12月在成都军区八一骨科医院治疗的44例桡骨远端骨折患者,所有患者均采取手法整复夹板固定方案治疗,将其分为两组,各22例。对照组进行常规康复活动;观察组进行阶梯性康复训练,对比治疗后两组患者的腕关节功能恢复情况。结果治疗后7 d,观察组患者的VAS评分、肿胀评分均明显低于对照组(P<0.05);治疗后3个月,观察组患者的桡尺偏活动度、屈伸活动度、旋转活动度均明显大于对照组(P<0.05)。结论进行手法整复夹板固定后,对患者进行阶梯性康复训练,可缓解早期疼痛、肿胀,促进腕关节功能恢复。 展开更多
关键词 桡骨 阶梯性 康复训练
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掌侧入路与背侧入路锁定钢板内固定治疗桡骨远端不稳定骨折的比较研究
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作者 刘鹏 《中国实用乡村医生杂志》 2019年第8期52-54,共3页
目的比较掌侧入路与背侧入路锁定钢板内固定治疗桡骨远端不稳定骨折的效果.方法收集开原市中心医院2014年6月—2018年6月收治的成人桡骨远端不稳定骨折患146例,随机分为掌侧入路组和背侧入路组各73例.两组分别采用掌侧入路和背侧入路进... 目的比较掌侧入路与背侧入路锁定钢板内固定治疗桡骨远端不稳定骨折的效果.方法收集开原市中心医院2014年6月—2018年6月收治的成人桡骨远端不稳定骨折患146例,随机分为掌侧入路组和背侧入路组各73例.两组分别采用掌侧入路和背侧入路进行手术,比较两组手术情况、术后6个月腕关节形态学和术后1年腕关节灵活度.结果掌侧入路组手术时间短于背侧入路组,术中出血量少于背侧入路组,并发症发生率低于背侧入路组,背伸活动度高于背侧入路组,差异均有统计学意义(P<0.05).结论相比于背侧入路治疗桡骨远端不稳定骨折,掌侧入路在手术时间、并发症发生率和背伸活动度上具有一定优势,可作为临床首选手术入路. 展开更多
关键词 桡骨 远端 骨折 掌侧入路 背侧入路
Assessing the oscillation of channel geometry and meander migration cardinality of Bhagirathi River,West Bengal,India
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作者 Rakhohori Bag Ismail Mondal Jatisankar Bandyopadhyay 《地理学报:英文版》 SCIE CSCD 2019年第4期613-634,共22页
Lateral migration of the Bhagirathi River temporally creates unavoidable geomorphic hazards in West Bengal,India.The Bhagirathi River flows SW for-67.30 km betwee n the confluenee point of Ajay and Jalangi rivers in E... Lateral migration of the Bhagirathi River temporally creates unavoidable geomorphic hazards in West Bengal,India.The Bhagirathi River flows SW for-67.30 km betwee n the confluenee point of Ajay and Jalangi rivers in East Burdwan and Nadia districts of West Bengal.The course of Bhagirathi is notably migration prone and cultivates problematic changes along its course over time.In the study,we have looked into its migration tendency and unpredictability for past 238 years and then predicted the lateral shifting of river centerline using temporal satellite imageries-Landsat-5(TM)of 1987(8,December),1995(28,January),2005(7,January)and LISS-IV satellite imagery(2017,5 January);SOI Toposheet-1968-1969(79A/2,79A/3,79A/6 and 79A/7)and RennelPs map of 1779.Other highlights are the quest of fluvial features,oxbow lakes,mid-channel bars,channel migration rate,meander geometry,channel sinuosity in different parts of river course and the parts that experience intensive bank erosion.The entire river course has been subdivided into three segments;viz.reaches A,B and C.Investigation displays that degree of sinuosity decreases from its anterior course(1968)to the existing course(2017).Reach-specific outputs display that reach B is highly sinuous(SI value 1.94 in 2017)and SI increases temporarily,whereas for reaches A and C it decreases with time.The rate of migration is higher in reach B than that in reaches C and A.The study displays a notably decreasing trend of migration in comparison with its previous lateral migration and shows that the migration nature over time is intensively inconsistent and unpredictable except very few portions of the river course.The nature of deposition within the river channel shows an unstable behavior during the entire period of the study.Meander geometry depicts a rapid change of river course innate to meander bends and shows a higher rate of migration by meander loop cut-off rather than lateral migration that reflects the inconsistency,erosion vulnerability and unpredictable nature of migration.Th 展开更多
关键词 channel GEOMETRY SINUOSITY INDEX BRAIDING INDEX MEANDER GEOMETRY radius of curvature bend tightness INDEX linear regression GIS
桡骨远端骨折桡侧移位对桡尺远侧关节稳定性的影响
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作者 刘小智 宋坤修 +4 位作者 马丙栋 赵多伟 李修国 曲玉磊 刘永涛 《中华手外科杂志》 CSCD 北大核心 2019年第6期437-440,共4页
目的探讨桡骨远端骨折移位造成桡尺远侧关节不稳的原因,分析桡骨远端骨折桡侧移位程度对腕关节稳定性的重要性。方法60例桡骨远端骨折患者,男22例,女38例;年龄26〜67岁,平均41岁。伴尺骨茎突骨折29例,不伴尺骨茎突骨折31例。均为桡骨远... 目的探讨桡骨远端骨折移位造成桡尺远侧关节不稳的原因,分析桡骨远端骨折桡侧移位程度对腕关节稳定性的重要性。方法60例桡骨远端骨折患者,男22例,女38例;年龄26〜67岁,平均41岁。伴尺骨茎突骨折29例,不伴尺骨茎突骨折31例。均为桡骨远端骨折块向桡侧移位,根据移位程度分三组:13例移位小于2 mm,20例大于2 mm、小于4 mm以及27例大于4 mm,均采用桡骨远端骨折掌侧切开复位钢板内固定术,术中放置钢板固定骨折后检查桡尺远侧关节稳定性。将术中物理检查桡尺远侧关节不稳定的15例患者(伴尺骨茎突骨折)分为两组,一组术中使用钢丝“8”字固定尺骨茎突,另一组不固定。分析桡骨远端骨折后桡侧移位程度对尺骨茎突的影响以及合并尺骨茎突骨折者对桡尺远侧关节稳定性的影响。随访掌倾角、尺偏角及腕关节功能评分来评价桡骨远端骨折桡侧移位程度及是否合并尺骨茎突骨折对桡尺远侧关节稳定性的影响。结果桡骨远端骨折桡侧移位大于4 mm时损伤TFCC是造成桡尺远侧关节不稳、影响腕部功能的主要原因。桡骨远端骨折是否伴有尺骨茎突骨折对桡尺远侧关节不稳发生率比较差异有统计学意义。桡骨远端骨折桡侧移位大于4 mm与尺骨茎突骨折之间差异有统计学意义。结论桡骨远端骨折桡侧移位对桡尺远侧关节的稳定性有较大的影响。桡尺远侧关节不稳中并发尺骨茎突骨折的患者较多,尺骨茎突骨折提示有较大几率伴发TFCC损伤。尺骨茎突的良好复位对桡尺远侧关节稳定性有重要作用。 展开更多
关键词 桡骨 骨折 桡尺远侧关节 三角纤维软骨复合体 尺骨茎突
High-Q, low-mode-volume microsphere-integrated Fabry–Perot cavity for optofluidic lasing applications
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作者 XIAOQIN Wu YIPEI WANG +4 位作者 QIUSHU CHEN YU-CHENG CHEN XUZHOU LI LIMIN TONG XUDONG FAN 《光子学研究:英文版》 CSCD 2019年第1期50-60,共11页
We develop a hybrid optofluidic microcavity by placing a microsphere with a diameter ranging from 1 to 4 μm in liquid-filled plano-plano Fabry–Perot(FP) cavities, which can provide an extremely low effective mode vo... We develop a hybrid optofluidic microcavity by placing a microsphere with a diameter ranging from 1 to 4 μm in liquid-filled plano-plano Fabry–Perot(FP) cavities, which can provide an extremely low effective mode volume down to 0.3–5.1 μm^3 while maintaining a high Q-factor up to 1 × 10^4–5 × 10^4 and a finesse of ~2000. Compared to the pure plano-plano FP cavities that are known to suffer from the lack of mode confinement, diffraction, and geometrical walk-off losses as well as being highly susceptible to mirror misalignment, our microsphere-integrated FP(MIFP) cavities show strong optical confinement in the lateral direction with a tight mode radius of only 0.4–0.9 μm and high tolerance to mirror misalignment as large as 2°. With the microsphere serving as a waveguide, the MIFP is advantageous over a fiber-sandwiched FP cavity due to the open-cavity design for analytes/liquids to interact strongly with the resonant mode, the ease of assembly, and the possibility to replace the microsphere. In this work, the main characteristics of the MIFP, including Q-factor, finesse, effective mode radius and volume, and their dependence on the surrounding medium’s refractive index, mirror spacing, microsphere position inside the FP cavity, and mirror misalignment, are systematically investigated using a finite-element method.Then, by inserting dye-doped polystyrene microspheres of various sizes into the FP cavity filled with water, we experimentally realize single-mode MIFP optofluidic lasers that have a lasing threshold as low as a few microjoules per square millimeter and a lasing spot radius of only ~0.5 μm. Our results suggest that the MIFP cavities provide a promising technology platform for novel photonic devices and biological/chemical detection with ultra-small detection volumes. 展开更多
关键词 mirror radius diameter optical devices down EASE spot
负极性直流电压作用下SF6气体中极不均匀电场局部放电特性研究
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作者 庞培川 孙泽明 +3 位作者 张芊 韩旭涛 侯志强 李军浩 《高电压技术》 EI CAS CSCD 北大核心 2019年第4期1093-1100,共8页
随着特高压直流输电技术(HVDC)的发展,以SF6作为主要绝缘介质的直流气体绝缘输电线路(GIL)受到越来越多的关注和研究。直流GIL中金属尖端缺陷会造成局部电场集中,引发局部放电,因此研究直流电压作用下SF6气体中极不均匀电场局部放电特... 随着特高压直流输电技术(HVDC)的发展,以SF6作为主要绝缘介质的直流气体绝缘输电线路(GIL)受到越来越多的关注和研究。直流GIL中金属尖端缺陷会造成局部电场集中,引发局部放电,因此研究直流电压作用下SF6气体中极不均匀电场局部放电特性可为直流GIL的建设提供试验依据,具有重要意义。通过搭建负直流高压局放试验平台,研究了SF6气体中气压、电场不均匀系数对起始放电电压(PDIV)的影响,并分析流注发展过程的放电特性。结果表明:随着气压的上升,PDIV增加,尖端曲率半径较小时,SF6气体对气压敏感程度随气压上升而增加,尖端曲率半径较大时SF6气体对气压敏感程度随气压增加而减小;随着电场不均匀系数的增加,PDIV减小,低气压下,SF6气体对电场不均匀程度敏感性较大,且随电场不均匀系数增加而降低,高气压下,SF6气体对电场不均匀程度敏感性较小,且随电场不均匀程度增加,敏感程度降低;放电过程可分为放电起始、流注发展和间歇击穿3个阶段。 展开更多
关键词 GIL 金属尖端 SF6 气压 曲率半径 PDIV 放电过程
RADIUS协议专题问答 预览
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作者 陈沪娟 《网络安全和信息化》 2019年第4期165-170,共6页
网络管理人员配置设备时需要熟悉一些网络协议,本文列举了Radius协议的一些知识以及可能遇到的问题,希望对大家的工作有所帮助。
关键词 认证协议 属性参数 字符串 服务器端 RADIUS 端口号码 服务器组
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顶级智能工厂的核心秘密
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作者 孟昭青(编译) 《上海质量》 2019年第10期50-52,共3页
本文原载于2019年2月期《工业周刊》。作者约翰·希奇(John Hitch)为杂志自由撰稿人,长期撰写有关机器人技术、工业物联网、3D打印和人工智能最新制造趋势和新兴技术的文章。快速半径(Fast Radius)公司的芝加哥新工厂被世界经济论... 本文原载于2019年2月期《工业周刊》。作者约翰·希奇(John Hitch)为杂志自由撰稿人,长期撰写有关机器人技术、工业物联网、3D打印和人工智能最新制造趋势和新兴技术的文章。快速半径(Fast Radius)公司的芝加哥新工厂被世界经济论坛誉为九大顶级智能工厂之一,在第四次工业革命中遥遥领先。本文介绍了该公司通过分布式工业级3D打印和专有操作系统,满足对产品快速周转和大规模定制日益增长的需求。 展开更多
关键词 智能工厂 3D打印 人工智能 机器人技术 操作系统 第四次工业革命 工业物联网 RADIUS
Diagnosis and Treatment of a Case of Radius and Ulna Fracture in Dog 预览
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作者 Shasha ZHAO Lijun DING 《农业生物技术:英文版》 CAS 2019年第2期116-118,共3页
60% of a dog s body weight is supported by its fore limbs, while the hind limbs mainly play the role of power, so the probability of dog s radius and ulna fracture is greatly increased. This paper mainly introduced th... 60% of a dog s body weight is supported by its fore limbs, while the hind limbs mainly play the role of power, so the probability of dog s radius and ulna fracture is greatly increased. This paper mainly introduced the diagnosis and treatment of a case of radius and ulna fracture in dog, with an attempt to provide reference for clinical practice. 展开更多
关键词 RADIUS and ULNA FRACTURE Diagnosis Treatment POSTOPERATIVE CARE
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Upper bounds for signless Laplacian Z-spectral radius of uniform hypergraphs
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作者 Jun HE Yanmin LIU +1 位作者 Junkang TIAN Xianghu LIU 《中国数学前沿:英文版》 SCIE CSCD 2019年第1期17-24,共8页
Let ■ be a k-uniform hypergraph on n vertices with degree sequence △= d1≥…≥ dn =δ. In this paper, in terms of degree di , we give some upper bounds for the Z-spectral radius of the signless Laplacian tensor (Q(... Let ■ be a k-uniform hypergraph on n vertices with degree sequence △= d1≥…≥ dn =δ. In this paper, in terms of degree di , we give some upper bounds for the Z-spectral radius of the signless Laplacian tensor (Q(■)) of ■. Some examples are given to show the efficiency of these bounds. 展开更多
关键词 HYPERGRAPH ADJACENCY TENSOR signless LAPLACIAN TENSOR spectral RADIUS
陈旧性桡骨头前脱位儿童患侧尺骨三维畸形的研究
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作者 姜海 苗武胜 +4 位作者 吴革 汪兵 吴永涛 屈继宁 李敏 《中华小儿外科杂志》 CSCD 北大核心 2019年第1期45-47,共3页
目的探讨和分析陈旧性桡骨头前脱位儿童患侧尺骨的三维畸形,以期能对临床治疗提供病理改变基础,指导临床手术。方法2016年6月至2017年1月收治7例陈旧性桡骨头前脱位患儿,男5例,女2例。年龄范围3~11岁,平均8岁。均为BadoⅠ型。受伤到测... 目的探讨和分析陈旧性桡骨头前脱位儿童患侧尺骨的三维畸形,以期能对临床治疗提供病理改变基础,指导临床手术。方法2016年6月至2017年1月收治7例陈旧性桡骨头前脱位患儿,男5例,女2例。年龄范围3~11岁,平均8岁。均为BadoⅠ型。受伤到测量时间为1~4年,平均2年5个月。通过双侧尺桡骨全段三维CT扫描,导入MIMICS10.01软件,重建出双侧尺骨三维图像。再通过镜像技术,将患侧尺骨与对侧尺骨进行矢状位、冠状位、轴位的对比测量。结果7例桡骨头前脱位儿童患侧尺骨与对侧尺骨比较,存在矢状位、冠状位、轴位的三维畸形改变。矢状位的过伸畸形最为明显,为12.14°~20.83°,平均为16.26°。冠状位的外翻畸形为5.44°~12.90°,平均为10.24°。轴位存在旋后畸形为6°~23°,平均为13.14°。结论陈旧性桡骨头前脱位儿童患侧尺骨存在明显的三维畸形,提示在临床不能单纯行尺骨近端后成角截骨治疗,可能需要同时矫正患侧尺骨的外翻和旋转畸形,这样才能完全矫正患侧尺骨的畸形,防止术后的桡骨头再脱位。 展开更多
关键词 桡骨 脱位 尺骨 儿童
基于有限元模型分析伸直型桡骨远端骨折的生物力学特点 预览 被引量:1
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作者 张朝驹 何川 +5 位作者 陈洪卫 庞启雄 万安 刘道东 Tsang WWN 李孝林 《中国组织工程研究》 CAS 北大核心 2019年第12期1898-1902,共5页
背景:老年人跌倒所致桡骨远端骨折临床发生率较高,从生物力学上分析受伤机制、预防骨折发生的研究非常重要但相对不足。目的:探讨伸直型桡骨远端骨折的生物力学特性。方法:选取29岁健康男性志愿者1名,对其前臂、腕关节、手进行CT扫描。... 背景:老年人跌倒所致桡骨远端骨折临床发生率较高,从生物力学上分析受伤机制、预防骨折发生的研究非常重要但相对不足。目的:探讨伸直型桡骨远端骨折的生物力学特性。方法:选取29岁健康男性志愿者1名,对其前臂、腕关节、手进行CT扫描。将扫描获得的CT图像导入三维成像软件Mimics 10.01建立腕关节背伸损伤的有限元模型,约束模型的手掌面,给予模型一个大小为2 m/s、方向垂直向下的速度载荷,观测载荷作用后腕关节软组织、骨骼的应力分布。结果与结论:建立了真实有效的腕关节背伸位有限元模型,载荷作用后软组织应力主要集中于手掌小鱼际以及腕背侧,骨骼应力背侧主要集中于尺桡骨下端,桡骨下端的应力最大、最集中,掌侧应力主要集中于尺桡骨中下段交界偏下处以及腕中部,尺桡骨的应力分布不对称。研究结果可用于伸直型桡骨远端骨折损伤机制的解释,可为腕关节背伸跌倒损伤的预防提供一定的生物力学依据。 展开更多
关键词 伸直型桡骨远端骨折 有限元分析 应力分布 CT数据重建 腕关节背伸跌倒 腕关节背伸位模型 腕关节 桡骨 组织工程
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A New Class AOR Preconditioner for L-Matrices
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作者 Reza BEHZADI 《数学研究及应用:英文版》 CSCD 2019年第1期101-110,共10页
Hadjidimos(1978) proposed a classical accelerated overrelaxation(AOR) iterative method to solve the system of linear equations, and discussed its convergence under the conditions that the coefficient matrices are irre... Hadjidimos(1978) proposed a classical accelerated overrelaxation(AOR) iterative method to solve the system of linear equations, and discussed its convergence under the conditions that the coefficient matrices are irreducible diagonal dominant, L-matrices, and consistently orders matrices. Several preconditioned AOR methods have been proposed to solve system of linear equations Ax = b, where A ∈ Rn×n is an L-matrix. In this work, we introduce a new class preconditioners for solving linear systems and give a comparison result and some convergence result for this class of preconditioners. Numerical results for corresponding preconditioned GMRES methods are given to illustrate the theoretical results. 展开更多
关键词 AOR iterative method L-MATRIX IRREDUCIBLE MATRIX spectral radius PRECONDITIONER ITERATION MATRIX
Ipsilateral proximal and distal radius fractures with unstable elbow joint: Which should we address first?
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作者 Nur Azuatul Akma Kamaludin Nur Azree Ferdaus Kamudin +1 位作者 Shalimar Abdullah Jamari Sapuan 《中华创伤杂志:英文版》 CAS CSCD 2019年第1期59-62,共4页
Simultaneous ipsilateral fractures involving radial head and distal end of radius are uncommon. We present our thoughts on which fracture should be addressed first. A 68-year-old lady sustained an ipsilateral fracture... Simultaneous ipsilateral fractures involving radial head and distal end of radius are uncommon. We present our thoughts on which fracture should be addressed first. A 68-year-old lady sustained an ipsilateral fracture of the right radial head and distal end of radius following a fall. Clinically her right elbow was posteriorly dislocated and right wrist was deformed. Plain radiographs showed an intraarticular fracture of the distal end of radius and a comminution radial head fracture with a proximally migrated radius. Magnetic resonance imaging (MRI) showed no significant ligament injuries. We addressed her distal radius first with an an atomical lock ing plate followed by her radial head with a radial head replacement. Our rationale to treat the distal end radius: first was to obtain a correct alignment of Lister's tubercle and correct the distal radius height. Lister's tubercle was used to guide for the correct rotation of the radial head prosthesis. Correcting the distal end fracture radial height helped us with length selection of the radial head prosthesis and address the proximally migrated radial shaft and neck. Postoperative radiographs showed an acceptable reduction. The Cooney score was 75 at 3 months postoperatively, which was equivalent to a fair functional outcome. 展开更多
关键词 Simultaneous IPSILATERAL FRACTURES Radius FRACTURES IRREDUCIBLE elbow dislocation RADIAL HEAD RADIAL HEAD ARTHROPLASTY
Doping radius effects on an erbium-doped fiber amplifier
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作者 Md.Ziaul Amin Khurram Karim Qureshi Md.Mahbub Hossain 《中国光学快报:英文版》 SCIE EI CAS CSCD 2019年第1期14-19,共6页
In an erbium-doped fiber amplifier(EDFA), erbium ions act as a three-level system. Therefore, much higher pump energy is required to achieve the population inversion in an erbium-doped fiber(EDF). This higher pump ene... In an erbium-doped fiber amplifier(EDFA), erbium ions act as a three-level system. Therefore, much higher pump energy is required to achieve the population inversion in an erbium-doped fiber(EDF). This higher pump energy requirement complicates the efficient design of an EDFA. However, efficient use of the pump power can improve the EDFA performance. The improved performance of an EDFA can be obtained by reducing the doping radius of the EDF. A smaller doping radius increases pump–dopant interactions and subsequently increases the pump–photon conversion efficiency. Decreasing the doping radius allows a larger proportion of dopant ions,which are concentrated near the core, to interact with the highest pump intensity. However, decreasing the doping radius beyond a certain limit will bring the dopant ions much closer and introduce detrimental ion–ion interaction effects. In this Letter, we show that an optimal doping radius in an EDF can provide the best gain performance. Moreover, we have simulated the well-known numerical aperture effects on EDFA gain performance to support our claim. 展开更多
关键词 DOPING RADIUS EFFECTS ERBIUM-DOPED FIBER AMPLIFIER
Magnetorheological finishing of an irregular-shaped small-bore complex component using a small ball-end permanent-magnet polishing head 预览
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作者 Henan Liu Jian Cheng +1 位作者 Tingzhang Wang Mingjun Chen 《纳米技术与精密工程(英文)》 CAS CSCD 2019年第3期125-129,共5页
A novel magnetorheological finishing(MRF)process using a small ball-end permanent-magnet polishing head is proposed,and a four-axes linkage dedicated MRF machine tool is fabricated to achieve the nanofinishing of an i... A novel magnetorheological finishing(MRF)process using a small ball-end permanent-magnet polishing head is proposed,and a four-axes linkage dedicated MRF machine tool is fabricated to achieve the nanofinishing of an irregularψ-shaped small-bore complex component with concave surfaces of a curvature radius less than3 mm.The processing method of the complex component is introduced.Magnetostatic simulation during the entire finishing path is carried out to analyze the material removal characteristics.A typicalψ-shaped small-bore complex component is polished on the developed device,and a fine surface quality is obtained with surface roughness Raof 0.0107μm and surface accuracy of the finished spherical surfaces of 0.3320μm(PV).These findings indicate that the proposed MRF process can perform the nanofinishing of a kind of small-bore complex component with small-curvature-radius concave surfaces. 展开更多
关键词 Complex component Magnetorheological finishing Magnetostatic simulation Small curvature radius
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Do we really need to repair the pronator quadratus after distal radius plating?
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作者 Subodh Pathak Rashid Anjum +4 位作者 Rakesh Kumar Gautam Pritam Maheshwari Jatin Aggarwal Aryan Sharma Vineet Pruthi 《中华创伤杂志:英文版》 CAS CSCD 2019年第6期345-349,共5页
Purpose:Fractures of distal radius are one of the common orthopaedic injuries.Placing the plate on volar surface requires release of underlying pronator quadratus(PQ)muscle.No consensus is present in the literature ab... Purpose:Fractures of distal radius are one of the common orthopaedic injuries.Placing the plate on volar surface requires release of underlying pronator quadratus(PQ)muscle.No consensus is present in the literature about the repair or not of the PQ.The purpose of this study was to evaluate the influence of PQ repair on functional outcome and complications.Methods:Retrospectively 83 patients of distal radius fractures managed with volar plating between 2014 and 2016 were evaluated.Demographic data,operative notes and physical therapy records were retrieved.Patients were divided into group A where PQ repair was done and group B where no repair was done.Functional data such as range of motion(ROM),grip strength,visual analogue scale(VAS)score and disabilities of arm,shoulder and hand(DASH)score at 4 weeks,3 months,6 months and finial follow-up were retrieved.Results:Totally 63 patients(n=29 in group A and n=34 in group B)with the mean age of 51.64 years were examined.Patients were followed up for a mean of 35.2 months(range 27.2-47.1 months)in group A and 38.6 months(range 28.6-51.0 months)in group B.Though functional outcome of the affected limb was not significantly different between two groups after 3 months,PQ repair did affect the recovery at an early stage.Repair group had significantly better ROM(p=0.0383)and VAS score at 4 weeks(p=0.017)while grip strength(p=0.014)was significantly better at 3 months.Conclusions:Repair of PQ may provide pain relief and increased ROM in early postoperative period and hence every attempt should be made to achieve the repair. 展开更多
关键词 Distal radius fractures Disabilities of arm shoulder and hand Volar plate Pronator quadratus Grip strength
不同年龄段中、晚期孕妇骨密度水平的差异性比较 预览
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作者 黄丽仟 孔存青 +7 位作者 舒文博 周鹤 赖秋荣 陈润 唐成 杨雅茱 张文海 刘鹏 《中国组织工程研究》 CAS 北大核心 2019年第35期5582-5586,共5页
背景:随着优生优育意识的增强和国家二胎政策的开放,人们对于孕期保健也日益重视,尤其是妊娠期营养的摄入和骨质健康状况越来越受社会的关注。目的:通过比较和分析不同年龄、不同孕期妇女骨密度的变化情况,为孕产妇保健工作提供科学合... 背景:随着优生优育意识的增强和国家二胎政策的开放,人们对于孕期保健也日益重视,尤其是妊娠期营养的摄入和骨质健康状况越来越受社会的关注。目的:通过比较和分析不同年龄、不同孕期妇女骨密度的变化情况,为孕产妇保健工作提供科学合理营养指导,预防孕期骨密度下降。方法:选择2017年6月至2018年4月在南宁市第八人民医院产检的不同孕期孕妇531例,均为广西籍贯原住居民,均自愿参加检测,并签署知情同意书。将其按照孕周和年龄进行分组,并对各组孕妇的桡骨骨密度进行超声检测,并对孕期年龄、孕周与骨密度进行相关性分析。结果与结论:①中、晚孕期女性骨密度降低情况差异无显著性意义(P>0.05);②不同年龄孕期女性的声速值和T值差异有显著性意义,且随年龄增加呈上升趋势(P<0.05);③孕中期女性的声速值和T值均随年龄增加呈上升趋势,差异有显著性意义(P<0.05),而孕晚期女性的骨密度指标在不同年龄组之间差异无显著性意义(P>0.05);④提示孕中期和孕晚期女性的骨密度差异不显著,但年龄是影响孕妇骨密度的因素之一;关注孕期骨密度变化,对增强母体的骨质健康和保证胎儿正常发育有重要意义。 展开更多
关键词 孕妇 年龄 骨密度 桡骨 超声 孕中期 孕晚期
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