Meta-analysis of the efficacy of volar plate internal fixation versus closed reduction and external fixation in the treatment of adult distal radius fractures

Objective:To compare the efficacy of open reduction and volar locking plate internal fixation with closed reduction and external fixation in the treatment of distal radius fractures by using meta analysis.Methods:The databases of CNKI,Wanfang,Weipu,Chinese biomedical literature,Pubmed,Embase,and Cochrane Library were retrieved,and the randomized controlled studies that directly compared the efficacy of plate internal fixation and closed reduction external fixation in the treatment of distal radius fractures published publicly from the establishment of the database to April 2023 were collected.The two researchers independently screened the retrieved literature according to the inclusion and exclusion criteria,extracted data,used Cochrane risk bias assessment tool for quality assessment,and used RevMan 5.4 software for meta analysis.Results:A total of 10 randomized controlled trials were included,all of which were in English.There were 1042 patients in total,and 9 of them were rated as low risk.Meta analysis results showed that one year after the treatment of distal radius fracture with volar locking plate internal fixation,DASH score[MD=-5.64,95%CI(-7.21,-4.06),P<0.00001];One year later,PRWE score[MD=-5.90,95%CI(-8.88,-2.92),P=0.001];Palm flexion[MD=5.92,95%CI(1.29,10.55),P=0.01];Pronation[MD=2.48,95%CI(0.59,4.36),P=0.01];Postrotation[MD=4.73,95%CI(2.15,7.31),P=0.0003];Grip strength[MD=0.61,95%CI(0.12,1.10),P=0.02];palmar tilt angle[MD=9.84,95%CI(5.66,14.02),P<0.00001];Radial inclination[MD=4.33,95%CI(2.97,5.69),P<0.00001]was superior to closed reduction plaster or splint external fixation.One year later,the European Five dimensional Health Scale(EQ-5D-5L)score[MD=0.02,95%CI(-0.01,0.05),P=0.27];Back extension[MD=2.22,95%CI(-4.15,8.59),P=0.49];Ulnar deviation[MD=3.49,95%CI(-0.80,7.78),P=0.11];Radial deviation[MD=2.05,95%CI(-2.39,6.50),P=0.37];Ulnar variance[MD=-1.14,95%CI(-3.16,0.88),P=0.27];There was no significant difference in complications[MD=0.77,95%CI(0.54,1.10),P=0.16](P>0.05).Conclusion:Based on the current clinical data,internal fixation with volar locking plate is more conducive to mid-term DASH score and grip strength recovery than closed reduction plaster or splint external fixation,but there is no significant difference in the quality of life and complications of patients.For adult distal radius fractures,surgical indications should be carefully grasped,and non operative treatment should be given priority.

A Research for Regional Contribution Rate of Internal Source and External Source of PM_(2.5) Based on Set Pair Analysis Method

A problem of the air pollution control in China is getting to know a regional contribution rate of internal and external source of PM2.5. In this paper,Set Pair Analysis（ SPA） method is proposed to calculate the contribution rate of PM2.5in Dongguan City. Due to geographic,meteorological factors and the low concentration of air pollutants in Qingxi area,the PM2.5in this place is mainly contributed by the regional transport of air pollutants from other inside areas of Dongguan,and less affected by the outside of Dongguan. So the concentration of PM2.5in Qingxi area can reflect the Dongguan＇s basic background concentration of PM2.5. On the basis of the basic background concentration,firstly the concentration of each pollutant components is divided into the internal part and the mixed part. Secondly using the source apportionment samples of five monitoring sites in Dongguan we can respectively construct a sample set A and an evaluation set B. Thirdly the SPA is operated onto the mixed part in terms of set B.At last the connection degree between the concentration of each pollutant components and external source and internal source will be calculated,that is the contribution rate. The research reveals that the contribution rate of internal source and external source of PM2.5in Dongguan City is 83%and 17% respectively,which roughly met expectations. This method is simple and effective and it can provide a reference for the government taking reduction measures to control PM2.5pollutants emission.

Internal and external disturbances aware motion planning and control for quadrotors

Resilient motion planning and control,without prior knowledge of disturbances,are crucial to ensure the safe and robust flight of quadrotors.The development of a motion planning and control architecture for quadrotors,considering both internal and external disturbances(i.e.,motor damages and suspended payloads),is addressed.Firstly,the authors introduce the use of exponential functions to formulate trajectory planning.This choice is driven by its ability to predict thrust responses with minimal computational overhead.Additionally,a reachability analysis is incorporated for error dynamics resulting from multiple disturbances.This analysis sits at the interface between the planner and controller,contributing to the generation of more robust and safe spatial–temporal trajectories.Lastly,the authors employ a cascade controller,with the assistance of internal and external loop observers,to further enhance resilience and compensate the disturbances.The authors’benchmark experiments demonstrate the effectiveness of the proposed strategy in enhancing flight safety,particularly when confronted with motor damages and payload disturbances.

Nonlinear finite element analysis of three implant-abutment interface designs

The objective of this study was to investigate the mechanical characteristics of implant-abutment interface design in a dental implant system, using nonlinear finite element analysis （FEA） method. This finite element simulation study was applied on three commonly used commercial dental implant systems： model I, the reduced-diameter 3i implant system （West Palm Beach, FL, USA） with a hex and a 12-point double internal hexagonal connection; model II, the Semados implant system （Bego, Bremen, Germany） with combination of a conical （45° taper） and internal hexagonal connection; and model III, the Br,~nemark implant system （Nobel Biocare, Gothenburg, Sweden） with external hexagonal connection. In simulation, a force of 170 N with 45°oblique to the longitudinal axis of the implant was loaded to the top surface of the abutment. It has been found from the strength and stiffness analysis that the 3i implant system has the lowest maximum yon Mises stress, prirlcipal stress and displacement, while the Br^nemark implant system has the highest. It was concluded from our preliminary study using nonlinear FEA that the reduced-diameter 3i implant system with a hex and a 12-point double internal hexagonal connection had a better stress distribution, and produced a smaller displacement than the other two implant systems.

Numerical Analysis of Three-Layer Deep Tunnel Composite Structure

To date,with the increasing attention of countries to urban drainage system,more and more regions around the world have begun to build water conveyance tunnels,sewage pressure deep tunnels and so on.However,the sufficient bearing capacity and corrosion resistance of the structure,which can ensure the actual service life and safety of the tunnel,remain to be further improved.Glass Fiber Reinforced Plastics(GFRP)pipe,with light weight,high strength and corrosion resistance,has the potential to be applied to the deep tunnel structure.This paper proposed a new composite structure of deep tunnel lined with GFRP pipe,which consisted of three layers of concrete segment,cement paste and GFRP pipe.A new pipe-soil spring element model was proposed for the pipesoil interaction with gaps.Based on the C3D8R solid model and the Combin39 spring model,the finite element numerical analysis of the internal pressure status and external pressure stability of the structure was carried out.Combined with the checking calculation of the theoretical formula,the reliability of the two finite element models was confirmed.A set of numerical analysis methods for the design and optimization of the three-layer structure was established.The results showed that from the internal GFRP pipe to the outer concrete pipe,the pressure decreased from 0.5 to 0.32 MPa,due to the internal pressure was mainly undertaken by the inner GFRP pipe.The allowable buckling pressure of GFRP pipe under the cover of 5 GPa high modulus cement paste was 2.66 MPa.The application of GFRP pipe not only improves the overall performance of the deep tunnel structure but also improves the construction quality and safety.The three-layer structure built in this work is safe and economical.

Middle or low water pressure direct spiral double helix converging nozzle structure optimization and flow field analysis

In order to solve the problem of using new nozzle is proposed in fire rescue robot. middle or low water pressure to form fine water mist, a Existing water mist nozzles are basically used for high pressure and in large size, complex structure and poor low pressure atomization effect in comparison with requirement of snake-like fire rescue robots. On the basis of comprehensive typical spray noz- zles, a direct spiral double helix converging nozzle （DSDHCN） is proposed, which has the advanta- ges of small volume, light weight, simple structure, and convenient installation. To make the spray nozzle have good performance, and meet the requirements of more efficient fire extinguishing, a nu- merical study is carried out to analyze the internal and external full flow field of nozzle. A gas-liquid two-phase flow is applied to simulate the external full flow field of nozzle with VOF model in fluent software. The simulation results show the real situation of water flow out of the atomization nozzle and the water jet trajectory. Some simulations about middle or low water pressure direct spiral double he- lix converging optimized nozzle have been done in 30bar pressure. The simulation results show that the optimized nozzle structure not only makes the spray droplets have a good cone angle, but also have a sufficient axial velocity,which proves the structure rationality of the proposed optimized nozzle.

Strategic Focus and Business Model Organization： The Mean Field Analysis Approach

The objective of this research is to show a new methodology for modeling phenomena present in complex economic systems. The case study we analyzed is the adoption of open organization model among firms operating in a particular industry. A firm with an open system model creates and captures value taking advantage not only from the internal resource but also from external. The organization could approach to open model acquisition using different focus： external focus namely looking out of its boundary, acting and reacting to competitor innovation, costumers＇ changing, demand growth, or internal focus remaining inside its boundary improving its best capabilities ignoring what happened outside （Vagnani, Moran, ＆ Simoni, 2010）. The actors involved are firms, customers and suppliers linked together through a business to business model. The methodology is based on an Object-Oriented Analysis Field Model that allows to intuitively describe systems characterized by a large number of objects that interact, as in this case of a system composed by different organizational entities. The system simulation allows to analyze how the actors influence the acquisition and diffusion of the open organization model. This approach permits the generation of different classes of objects to represent all actors involved in the evolution of the system and to define the dynamics that determine their interaction. The solution of the model can be approximated using the Mean-Field analysis technique （Kurtz, 1978）, following the results proposed in Bobbio, Gribaudo, and Yelek （2008）. A qualitative result is illustrated in order to show the applicability of the proposed methodology and to emphasize its relevant features： flexible modeling approach, capacity of solving complex systems and output management facilities. The presented model is comprehensive and its scope is wide; it could be used to study the behavior of enterprises changing model in many different scenarios and situations. In future works quantitative results will be given, and different situations will be analyzed.

事务所规模与年报会计政策“类准则”披露——基于文本分析的经验证据

通过计算上市公司年报会计政策披露的“类准则”程度,讨论会计师事务所规模是否为影响上市公司会计政策披露行为的重要因素。研究发现:(1)由规模较大的会计师事务所审计的上市公司,年报会计政策披露的“类准则”程度较低,会提供更多公司会计政策的个性化信息。(2)在上市公司风险增强和会计准则重大变化的两大类场景中,事务所规模与年报会计政策披露“类准则”程度之间的关系都得到增强,说明事务所的风险压力和事务所能力是重要的机制路径。(3)由同一事务所审计的上市公司会计政策披露的“类准则”程度更一致,具有同所效应。(4)基于会计师事务所变更的检验发现,若变更后的事务所规模更大,则会计政策披露的“类准则”程度会降低;若变更后的事务所规模更小,则会计政策披露的“类准则”程度会提高。

弯管内外表面腐蚀缺陷力学-电化学相互作用规律研究

为进一步研究弯管内外表面腐蚀缺陷力学-电化学(M-E)相互作用规律,建立基于多物理场耦合的弯管内外表面含腐蚀缺陷的三维模型,研究内压和缺陷几何形状对M-E相互作用规律及对弯管的影响。研究结果表明:当弯管内外表面存在腐蚀缺陷时,弯管内侧的M-E效应更强,增加应力和腐蚀的增长速率,使内侧更容易发生失效;当缺陷几何增长时,应力在缺陷长度和宽度方向上增长,腐蚀主要在缺陷长度方向上增长;外表面缺陷附近的应力和腐蚀增长规律基本一致,而内表面缺陷附近的应力增长较腐蚀增长更为复杂。研究结果可为含腐蚀缺陷弯管评估模型的完善以及管道系统完整性的管理提供理论参考。

Quantitative Analysis of Fe Content in Iron Ore via External Calibration in Conjunction with Internal Standardization Method Coupled with LIBS

The external calibration in conjunction with internal standardization（ECIS） coupled with laser-induced breakdown spectroscopic（LIBS） technique was proposed to perform the quantitative analysis of Fe content in iron ore The plasma temperature and the electron number density were calculated to prove that the plasma was under local thermodynamic equilibrium（LTE） conditions and to ensure that the integral intensities of Fe I lines were reasonable. In addition, the result of the quantitative analysis shows a content of （20.26±0.59）% by mass of Fe in the iron ore. It was determined by four calibration curves, drawn for four emission lines of Fe I（373.48, 373.71,404.58 and 438.35 nm） normalized by Mn I line, base on the ECIS method which can eliminate the influence of matrix effect and improve the accuracy of quantitative analysis, compared with the standard addition method. Both the results of these two analytical methods were compared with that listed in the Standard Substance Certificate. The percentage content of Fe in the same sample of iron ore by the ECIS method was （20.17±0.08）% by mass, which shows a good performance to analyze the Fe content of iron ore in combination with LIBS.

抽水蓄能机组水轮机工况启动过程内部流场分析

本文采用CFD数值模拟的方法,模拟计算了抽水蓄能机组在水轮机工况启动过程内部流场特征。得到了在活动导叶开启过程中的速度、压力随时间的瞬态分布规律,讨论了蓄能机组开启过程中外特性的变化曲线。结果表明:活动导叶的开启规律可以大体分为五个阶段。活动导叶的开启规律是先缓慢开启,然后以较快的速度关闭,最后再保持到空载的开度,从第四阶段,导叶再逐渐打开直到额定开度。转轮扭矩和机组流量呈现出先增大后减小的趋势,当导叶逐渐打开时,转轮扭矩和机组流量再逐渐上升。本文为研究蓄能机组水轮机工况下启动过程的内部流动变化提供了参考依据,同时对提高水轮机工况的启动稳定性具有重要意义。

支架外固定与钢板内固定治疗桡骨远端粉碎性骨折的Meta分析

目的:外固定支架和钢板内固定作为桡骨远端粉碎性骨折的常用治疗方法,在临床上各有利弊。系统评价外固定支架与钢板内固定治疗粉碎性桡骨远端骨折的临床疗效及安全性,为桡骨远端骨折中西医结合诊疗指南研制提供论证依据。方法:系统检索PubMed、Web of Science、Embase、Cochrane Library、中国知网、中国生物医学文献数据库、维普和万方数据库,纳入2013年10月至2023年10月发表的关于外固定支架和钢板内固定治疗粉碎性桡骨远端骨折的随机对照试验文献,按照纳入标准和排除标准筛选文献,使用Review Manager进行文献质量评价和Meta分析。结果:(1)纳入8篇文献,其中中文文献4篇,英文文献4篇、总样本量648例,外固定支架组328例,钢板内固定组320例;(2)术后3个月,钢板内固定组的背伸、掌屈、旋后范围优于外固定支架组;术后12个月,钢板内固定组的握力、掌倾角、掌屈、旋前和旋后范围优于外固定支架组;钢板内固定组在术后感染方面优于外固定支架组,其余结局指标两组差异均无显著性意义。结论:现有8项证据表明,在粉碎性桡骨远端骨折的治疗方式选择上,外固定支架与切开钢板内固定都有良好的治疗效果,综合其他因素钢板内固定更胜一筹,但是对于一些高度严重的粉碎性桡骨远端骨折、骨质较差、严重污染的开放性骨折以及软组织肿胀而无法进行切开手术的特殊患者,外固定支架才是首选。此次研究结果具有局限性,未来还需要开展更多高质量、大样本、多中心的随机对照试验研究,另外需重视远期疗效、其他次要指标的观察,补充优化当前研究结果。

天然气重整SOFC/MGT混合分布式供能系统性能分析

针对固体氧化物燃料电池(SOFC)与微型燃气轮机(MGT)构成的混合分布式供能系统,首先建立了一种管式SOFC准二维数值模型,优化了辐射计算,提高了热传递模型的准确性;考虑了CO及H2同时作为燃料参加电化学反应,并完善了损失计算模型;最后采用所发展的系统性能预测模型,分别在内部重整和外部重整情况下,预测比较了两种SOFC/MGT混合系统的性能,结果表明外部重整系统在系统输出功率、CO2排放以及热应力分布方面都比内部重整系统具有优势,然而这种轻微的优势是需要额外增加外部重整器的设备投资换取的。

联合辛麻颗粒对慢性阻塞性肺疾病急性加重期外寒内饮证患者临床疗效和免疫功能的影响

目的观察慢性阻塞性肺疾病急性加重期外寒内饮证患者联合辛麻颗粒治疗的临床疗效。方法选择2023年8月至2024年4月收治的60例慢性阻塞性肺疾病急性加重期外寒内饮证患者,根据治疗方法分为对照组(n=30)和观察组(n=30)。对照组采用常规西药治疗,观察组采用常规西药联合辛麻颗粒治疗。比较2组临床疗效、血气分析[动脉血氧分压(PaO_(2))、动脉血二氧化碳分压(PaCO_(2))、血氧饱和度(SaO_(2))]、免疫指标及不良反应。结果2组总有效率观察组96.67%(29/30)高于对照组73.33%(22/30)(P<0.05)。治疗后,观察组PaO_(2)、SaO_(2)、IgA、IgG、IgM、CD3+、CD4+、CD4+/CD8+高于对照组,PaCO_(2)、CD8+低于对照组(P<0.05)。2组不良反应发生率比较无统计学差异(P>0.05)。结论慢性阻塞性肺疾病急性加重期外寒内饮证患者采用常规西药联合辛麻颗粒治疗,对免疫功能、血气分析指标有明显的改善作用,临床疗效较好、安全性较高。

中医内外治法干预慢性心力衰竭系统评价研究进展

慢性心力衰竭是各种心脏疾病的终末阶段,在我国患病率及发病率呈现上升趋势。现代医学是临床治疗慢性心力衰竭的主要手段,但可能产生不良影响。目前,已有大量研究证实,中医治疗慢性心力衰竭优势显著,分析总结2017年至今中医内外治法干预慢性心力衰竭的系统评价/Meta分析,总结中医内外治法治疗慢性心力衰竭的成果,分析中医内外治法研究现阶段尚存的问题并提出解决措施,为临床治疗慢性心力衰竭提供参考。

港口集装箱起重机防雷措施及应用

针对港口集装箱起重机频繁遭受雷击的现状,在防雷分区分析的基础上,结合起重机不同位置的防雷要求和内部各系统特性,从外部防雷和内部防雷2个方面,提出防雷措施。实践表明,该措施可提高港口运营的稳定性和安全性。

叶片不同切割形状对离心泵各项性能的影响

离心泵叶片直接影响离心泵的效率与使用寿命,因此,对叶片形状进行研究具有重要意义。对离心泵叶片出口边进行单一切割以改变离心泵性能,在此基础上,对叶片前缘、尾缘进行了双向切割,研究了不同切割形状对离心泵各项性能的影响。首先,以一台n_s=73的离心泵作为研究对象,使用UG软件进行了离心泵三维建模与叶片切割(切割出了24种叶片模型);然后,使用ICEM软件划分了网格,选用标准k-ε湍流模型作为计算模型,在离心泵叶片与蜗壳隔舌处设置了监测点;最后,采用ANSYS CFX软件,对无切割和切割后的模型进行了离心泵数值模拟计算,得到了离心泵在0.6Q_(d)~1.4Q_(d)工况下的外特性曲线;在外特性良好的前提下,研究了其内部流动结构、压力脉动特性,以及湍动能分布。研究结果表明:在1.0Q_(d)设计工况下,切割后的模型较无切割模型的效率均提升了4%左右,对称切割的模型中前缘为椭圆、尾缘为钝形的模型7的效率提升最高,提升了4.8%,非对称切割前缘为圆形、尾缘为背面半切割的模型14效率提升了5.4%;无切割模型内部流线紊乱且内部相对速度高的区域较多,非对称切割的模型14叶轮内部流线分布均匀且相对速度值和分布区域减小;相对于无切割模型,切割后的模型内部压力升高,对称切割的模型7压力脉动减小了10%,而非对称切割的模型14压力脉动强度增加了近30%;切割后的模型湍动能分布明显改善,尾缘处湍动能值减小,对称切割的模型7湍动能随时间变化而变化不大,表现更稳定。综合不同切割模型的外特性及稳定性表现可知,将前缘切割为椭圆、尾缘切割为钝形,能有效提升离心泵的性能。

医药企业社会责任履行的影响因素组态与路径研究

以209家进行企业社会责任评分的A股医药上市公司作为研究对象,基于企业内外整合视角,运用模糊集定性比较分析(fsQCA)方法,探究内部驱动因素(财务绩效、技术创新、高管薪酬、内部控制)和外部约束因素(政府干预度、法律环境)的匹配效应对医药企业社会责任履行的复杂影响机制。研究表明,企业内部驱动因素与外部约束因素的不同组合对医药企业社会责任履行起到“殊途同归”的效果;医药企业社会责任高履行路径有5条,分别是高管引领经济驱动型、内控强化经济驱动型、高管引领内控驱动型、法律保护能力驱动型和内控强化压力驱动型;导致医药企业社会责任低履行的路径有1条,且与社会责任高履行的驱动机制存在非对称性。研究结论有助于厘清影响医药企业社会责任履行的多重复杂因素间互动本质,并为医药企业如何采取有效措施更好地履行社会责任带来有益的实践启示。

职业教育数字化转型的影响因素及复杂组态路径分析——基于“资源—动力”模型的混合实证研究

推进数字技术与职业教育深度融合既是深化现代职业教育体系建设的快车道,也是助力新时代职业教育从“大有可为”到“大有作为”的新赛道。研究基于资源基础理论和动力能力理论构建“资源—动力”模型,以我国26所职业院校为案例样本,采用模糊集定性比较分析法(fsQCA),探索性地识别内部资源禀赋和外源性动力对推进职业教育数字化转型的联动效应与适配性选择方案。研究发现:(1)技术资源、组织资源、环境资源、政府支持、学校竞争以及企业需求等单一前因条件均无法独立成为职业院校数字化高水平建设的必要条件;(2)推进职业教育数字化转型的三种驱动模式为资源利用主导型、外部动力主导型、资源—动力耦合主导型。研究为加快职业教育高水平数字化建设提供了理论指导,为各职业院校因校制宜地开辟职业教育高质量发展新局面提供实践启示。

铁磁性构件内外侧缺陷重合度与漏磁场信号的关系

基于漏磁检测原理,利用COMSOL有限元仿真软件模拟了含缺陷小管径薄壁管道的漏磁检测信号特征,研究了管壁内外侧都存在缺陷时漏磁场信号的变化情况;同时,采用局部直流磁化及控制变量的方法研究了管壁内外侧缺陷的漏磁场信号分布。结果表明,管道壁厚在超过6 mm时得到的漏磁场信号切向分量的双波峰间峰值差较小,内外侧缺陷的重合度在小于40%时已不易于判定;当缺陷宽度小于2mm时,漏磁场切向分量分布图中的双波峰间峰值差变化较小,从而无法对内侧缺陷参数进行判定。该结果为研究内外侧缺陷的重合度与漏磁信号之间的关系以及薄壁管道的安全评定提供了一定依据。