骨形成蛋白载体材料研究进展

对于骨形成蛋白(bonemorphogeneticprotein,BMP)性的三载体材料的研究很多,主要包括无机性的、合成的多聚物、天然多聚物和三者的复合物4种,但各有不足之处,许多学者不断对其加以改进,并采用复合技术、理化方法等改善载体的性能,更有利于发挥BMP的诱骨活性。这对于进一步扩展BMP的临床应用范围,确保其安全性问题至关重要。

骨形成蛋白诱导活性材料联合自体骨移植治疗牙周骨下袋缺损的临床疗效研究

目的探讨骨形成蛋白诱导活性材料(OAM)联合自体骨移植治疗牙周骨下袋的缺损临床疗效。方法选取2014年3月-2016年4月海军总医院口腔科收治的牙周骨下袋缺损患者50例为研究对象,患牙56颗。56颗患牙随机分为治疗组与对照组,每组28颗。治疗组患者应用OAM联合自体骨移植结合引导组织再生术(GTR)进行修复,对照组患者单纯应用OAM结合GTR进行修复,对比观察两组牙周在手术前及手术后12、24w的牙周临床附着丧失(CAL)、牙周探诊深度(PPD)、龈沟出血指数(SBI)。结果与手术前比较,治疗组与对照组患者在手术后12、24wCAL均明显减少,且治疗组手术后12w的CAL低于对照组(P<0.05),手术后24w两组CAL比较差异无统计学意义(P>0.05);与手术前比较,治疗组与对照组患牙在术后12、24w的PPD与SBI均明显改善,且治疗组手术后12、24w牙周PPD与SBI明显低于对照组(P<0.05)。结论在GTR手术中应用OAM联合自体骨移植修复牙周骨下袋缺损的临床疗效明显。

冷喷涂固态颗粒沉积中颗粒间结合形成机制研究进展

就目前主流的冷喷涂颗粒结合形成机理进行了系统总结和评述,为冷喷涂沉积体性能的调控和后续研究提供借鉴。分别就经典的颗粒界面绝热剪切失稳结合机理,颗粒界面应力波释放诱导材料射流形成结合机理,以及高速碰撞诱导颗粒表面氧化膜破碎、新鲜金属接触结合机理的基本概念、原理、特点进行了概括总结。通过大量系统文献的调研,指出现有理论目前存在的相悖和不足之处,并简要分析了现有颗粒间结合形成理论对冷喷涂沉积体质量调控方面的指导意义。最后基于现有研究的不足,对冷喷涂颗粒界面结合机制方面的研究进行了展望。

骨形成蛋白修饰后的种植体用于牙列缺损种植治疗中的应用探讨

目的:观察骨形成蛋白修饰后的种植体对牙列缺损种植临床疗效的影响。方法:选择2017年1月-2017年12月笔者医院诊治的139例(共177颗牙)牙列缺损患者为研究对象,按牙列缺损种植术材料应用差异分为两组,合金对照组:共67例,83颗牙,行常规钛合金材料牙列缺损种植术;蛋白观察组:共72例,94颗牙,行骨形成蛋白复合材料饰后的牙列缺损种植术。观察两组的临床主客观疗效指标及不良反应差异。结果:自觉疗效性指标(种植牙美观度、自觉语言功能改善度、自觉咀嚼功能改善度)和客观疗效性指标(牙龈健康指数、龈沟出血指数、牙菌斑沉积指数)比较,蛋白观察组均优于合金对照组(P<0.05);不良反应效率比较,蛋白观察组(5.32%)低于合金对照组(15.66%)(P<0.05);种植牙骨整合系数ISQ比较,蛋白观察组高于合金对照组(P<0.05)。临床整体疗效(有效率)比较,蛋白观察组(93.61%)高于合金对照组(83.13%)(P<0.05)。结论:与常规钛合金材料比较,骨形成蛋白复合材料应用于牙列缺损种植修复的疗效显著,不仅具有较高安全性,而且在提升患者自觉满意度方面效果显著。

高校人事档案整理中具体问题的思考

目前,全国各级单位正按照中组部的通知精神集中开展人事档案专项审核工作,但由于人事档案工作长期以来未得到应有的重视,管理相对落后,给人事档案的整理带来了难度。本文拟从人事档案整理中遇到的具体问题入手,探索人事档案整理中一些共性的问题,从而为人事档案材料形成的规范化、制度化找到一些可供操作的办法,将沉睡的档案变成人事管理工作中的得力助手。

Analysis of bulging process of aluminum alloy by overlapping sheet metal and its formability

The influences of strength coefficient K, work hardening exponent n and thickness t of the overlapping sheet on bulging process are analyzed based on hardening material model. Also, bulging experiments are carried out by taking the aluminum alloy LF21 as formed sheet metal, and selecting overlapping sheet with different thicknesses and material properties, by which accuracy of the above analysis result is verified in the aspects of geometric shape, thickness distribution and limit bulging height. The results show that higher strength coefficient K, larger work hardening exponent n and proper thickness of the overlapping sheet are helpful to improve the formability and forming uniformity of formed sheet metal.

成年狗股骨微波灭活骨缺损模型的建立及其修复

目的 :建立成年狗股骨经微波灭活造成骨缺损的实验动物模型 ,并用复合骨形成蛋白材料修复。方法 :用自制的骨肿瘤微波治疗仪 ,以 1.5kHz、70W功率加热至 5 0℃～ 5 5℃ ,维持 2 0min ,造成狗股骨中段骨缺损 ,术后不同时段观察愈合情况。制备复合骨形成蛋白材料 ,经评价后植入骨缺损处修复并观察结果。结果 :在保持狗股骨连续性的前提下 ,长 2 .5cm、宽 1.0cm的骨缺损 9个月时无愈合倾向。复合骨形成蛋白材料具有成骨诱导活性和生物相容性、有粘合性和可塑型性 ,具备有利于新生血管长入的空间 ,可与宿主骨“生物铆定”。结论 :成年狗股骨微波造成的骨缺损实验模型 ,长 2 .5cm、宽 1.0cm 9个月不能自愈 ,适宜于各种骨修复材料的填充。复合骨形成蛋白材料修复微波灭活骨缺损效果良好 ,可作修复骨缺损的骨替代材料。

Mechanism of anti-arterial thrombosis of Dahuangzhecong Fang screened by Ti-Al intermetallic compound porous material

The mechanism of antithrombotic of Dahuangzhechong Fang separated and purified by Ti-Al intermetallic compound porous material (TAICPM) was researched. Dahuangzhechong Fang, which was isolated and screened by TAICPM, was used to oral rats. At the end of study, their blood and thrombus were collected. The results show that TAICPM with the pore size of 1-5 μm can screen Dahuangzhechong Fang well. Dahuangzhechong Fang can increase 6-keto-PGF1α, lower content of TXD2 and platelet. Dahuangzhechong Fang has good effect to resist arterial thrombosis.

Selective synthesis and shape-dependent photoluminescence properties of (Y_(0.95)Eu_(0.05))_2O_3 submicron spheres and microplates

Red-emission （Y0.95Eu0.05）2O3 submicron spheres and microplates were selectively obtained via hydrothermal precursor synthesis （150 °C, 12 h） followed by calcination at 1000 °C. Characterizations of the products were carried out by combined means of XRD, FT-IR, FE-SEM and PL analysis. The precursors could be modulated from basic-carbonate submicron spheres to normal carbonate microplates by increasing the molar ratio of urea to Y＋Eu from 10 to 40-100. The resultant oxides largely retain their respective precursor morphologies at 1000 °C, but morphology confined crystal growth was observed for the microplates, yielding more enhanced exposure of the （400） facets. Both the （Y0.95Eu0.05）2O3 spheres and microplates exhibit nearly identical positions of the PL bands and similar asymmetry factors of luminescence [I（5D0→7F2）/I（5D0→7F1）, ～11] under 250 nm excitation, but the microplates show a significantly strong red emission at ～613 nm （ ～1.33 times that of the spheres） owing to their larger particle size and denser packing of primary phosphor crystallites.

OAM联合自体骨移植治疗牙周骨下袋缺损临床研究

目的:观察骨形成蛋白诱导活性材料联合自体骨移植治疗牙周骨下袋缺损的临床效果。方法:选取2016年2月~2017年2月我科门诊收治的牙周骨下袋缺损患者64例为研究对象,按照手术方法不同分为对照组和观察组各32例。对照组行自体骨移植联合引导组织再生术治疗,观察组行骨形成蛋白诱导活性材料与自体骨移植联合引导组织再生术治疗。比较两组牙周探诊深度、龈沟出血指数及生活质量评分差异。结果:术后3、6个月,观察组PPD水平低于对照组,P<0.05;术后3、6个月,两组SBI均明显降低,术后组内比较有明显差异P<0.05,但组间术后比较无明显差异,P>0.05;术后6个月,观察组生活质量评分明显高于对照组,P<0.05。结论:骨形成蛋白诱导活性材料与自体骨移植联合引导组织再生术治疗牙周骨下袋缺损,可促进牙周组织修复,改善患者生活质量。

论建设山东半岛蓝色经济区与我国航运业的机遇

建设山东半岛蓝色经济区是包容航运业在内的系统发展战略,规划涉及的各项发展战略目标将推动我国航运业的发展,惠及集装箱运输、干散货及原油运输、港口码头等诸多航运产业领域,为我国航运业创造更多发展机遇,也提出了许多新挑战。

Cu-Al interfacial compounds and formation mechanism of copper cladding aluminum composites

Copper cladding aluminum(CCA)rods with the section dimensions of12mm in diameter and2mm in sheath thickness were fabricated by vertical core-filling continuous casting(VCFC)technology.The kinds and morphology of interfacial intermetallic compounds(IMCs)were investigated by SEM,XRD and TEM.The results showed that the interfacial structure of Cu/Al was mainly composed of layeredγ1(Cu9Al4),cellularθ(CuAl2),andα(Al)+θ(CuAl2)phases.Moreover,residual acicularε2(Cu3Al2+x)phase was observed at the Cu/Al interface.By comparing the driving force of formation forε2(Cu3Al2+x)andγ1(Cu9Al4)phases,the conclusion was drawn that theε2(Cu3Al2+x)formed firstly at the Cu/Al interface.In addition,the interfacial formation mechanism of copper cladding aluminum composites was revealed completely.

Bearing capacity and settlement of strip footing on geosynthetic reinforced clayey slopes

The effect of geosynthetic reinforcing on bearing capacity of a strip footing resting on georeinforced clayey slopes was investigated.The results of a series of numerical study using finite element analyses on strip footing upon both reinforced and unreinforced clayey slopes were presented.The objectives of this work are to:1) determine the influence of reinforcement on the bearing-capacity of the strip footings adjacent slopes,2) suggest an optimum number of reinforcement and 3) survey the effect of friction angle in clayey soils reinforced by geogrids.The investigations were carried out by varying the edge distance of the footing from slope.Also different numbers of geosynthetic layers were applied to obtaining the maximum bearing capacity and minimum settlement.To achieve the third objective,two different friction angles were used.The results show that the load?settlement behavior and ultimate bearing capacity of footing can be considerably improved by the inclusion of reinforcing layer.But using more than one layer reinforcement,the ultimate bearing capacity does not change considerably.It is also shown that for both reinforced and unreinforced slopes,the bearing capacity increases with an increase in edge distance.In addition,as the soil friction angle is increased,the efficiency of reinforcing reduces.

The asymptotic field of a dynamically growing crack in a viscoelastic materia

A mechanical model of a fracturing viscoelastic material was developed to investigate viscous effects in a dynamically growing crack-tip field. It was shown that in the stable creep-growing phase, elastic deformation and viscous deformation are equally dominant in the near-tip field, and stress and strain have the same singularity, namely, （σ-e）∝r^-1/（n-1）. The asymptotic solution of separating variables of stress, stain and displacement in the crack-tip field was obtained by asymptotic analysis, and the resulting numerical value of stress and strain in the crack-tip field was obtained by the shooting method and the boundary condition of a mode I crack. Through numerical calculation, it was shown that the near-tip fields are mainly governed by the creep exponent n and Mach number M. When n →∞, the asymptotic solution of a viscoelastic material can be degenerated into that of Freund＇s elastic-ideally plastic material by analyzing basic equations.

Microstructural and mechanical behavior of blended powder semisolid formed Al7075/B_4C composites under different experimental conditions

This work aimed to fabricate B4C reinforced aluminum matrix composites via blended powder semisolid forming that is an implementation of the benefits of semisolid forming to the powder metallurgy. Al7075 elements were incrementally added to ethanol solution under mechanical mixing. Al7075 constituents and B4C particles were blended in a high energy ball mill. Cold compacted Al7075/B4C blends were pressed at semisolid state. The effects of the size of the matrix（20, 45 and 63 μm）, reinforcing volume fraction（5%, 10% and 20%） and semisolid compaction pressure（50 and 100 MPa） on the morphology, microstructure, density, hardness, compression and bending strength were thoroughly analyzed. Experimental results revealed that the highest microstructural uniformity was achieved when large B4C particles（45 μm） were distributed within the small particles（20 μm） of the matrix phase. Composites with matrix particles larger than reinforcing phase indicated agglomerations in loadings more than 10%（volume fraction）. Agglomerated regions resisted against penetration of the liquid phase to the pores and lowered the density and strength of these composites. Composites with 20 μm Al7075 and 20%（volume fraction） 45 μm B4C powder pressed under 100 MPa exhibited the highest values of hardness（HV 190） and compressive strength（336 MPa）.

Formation mechanism and growth kinetics of TiAl_(3) phase in cold-rolled Ti/Al laminated composites during annealing

Cold-rolled Ti/Al laminated composites were annealed at 525−625℃for 0−128 h,and the interfacial microstructure evolution was investigated.The results indicate that only the TiAl_(3) phase was formed at the Ti/Al interface;most of TiAl_(3) grains were fine equiaxed with average sizes ranging from hundreds of nanometers to several microns and the TiAl_(3) grain size increased with increasing annealing time and/or temperature,but the effect of annealing temperature on the TiAl_(3) grain size was far greater than that of annealing time.The growth of the TiAl_(3) phase consisted of two stages.The initial stage was governed by chemical reaction with a reaction activation energy of 195.75 kJ/mol,and the reaction rate constant of the TiAl_(3) phase was larger as the Ti/Al interface was bonded with fresh surfaces.At the second stage,the growth was governed by diffusion,the diffusion activation energy was 33.69 kJ/mol,and the diffusion growth rate constant of the TiAl_(3) phase was mainly determined by the grain boundary diffusion owing to the smaller TiAl_(3) grain size.

Liquid Flow in Shaped Fiber Bundle

By computation and comparison of the critical spreading coefficient parameter, it was found that shaped fiber bundle is better for wetting. Liquid-air interface tension of liquid arising the shaped fiber bundle body is considered as one critical factor besides liquid viscosity, inertia force and liquid-fiber interface tension. Experimental result simulation demonstrated that the liquid-air interface tension is correlated with the geometric size of the liquid arising in body, Φ0 （x） and which is affected by the cross sectional shape of fiber and the radius of single fiber. The shaped fiber bundle model is/ntroduced to/nvestigate liquid flow in fiber assembly. The model is generated based on a random function for stochastic forming of fibers in bundle and it is necessary to combine this fundamental model with physical explanation for investigation of liquid flow in fiber assembly.

Structure optimization of polymeric Mach-Zehnder rib waveguide

A systematic analysis of the polymeric Mach-Zehnder rib waveguide is presented based on the calculation and optimization. The simulation is carried out with the Effective Index Method (EIM) and two-dimensional (2-D) Finite Difference Beam Propagation Method (FD-BPM). The large refractive index step between the consecutive polymer layers is reduced by using EIM and thus the precision of the calculation is ensured. The important param- eters of the waveguide such as Y-junction angle and the separation gap are discussed and their relationships with the optical power propagation and the loss characteristics are investigated in this paper. The total loss of the opti- mized structure is 0.258 dB.

Study on the Manufacturing Technology of Directly Metal Forming based on Overlay Welding

Rapid prototyping technology can greatly improve the actual processing industrial prototype; this paper introduces the main principle, characteristics and technology of rapid prototype manufacturing. The current rapid prototype manufacturing products and production problems are analyzed. Because of the direct metal forming process have the characteristic of point by point, surfacing with stack molding manufacturing layer by layer, so it is suitable for complex shape parts two-dimensional or three-dimensional functionally gradient materials manufacturing.