摘要：The bioinert nature of polyether ether ketone(PEEK)material limits the widespread clinical application of PEEK *** the porous structure is considered to improve osseointegration of PEEK implants,it is hardly used due to its mechanical *** study investigated the combined influence of the porous structure and in vivo mechanical stimulation on implantation safety and bone growth based on finite element analysis of the biomechanical behavior of the implantation *** combined control of pore size and screw preloads allows the porous PEEK implant to achieve good osseointegration while maintaining a relatively high safety level.A pore size of 600μm and a preload of 0.05 N·m are the optimal combination for the long-term stability of the implant,with which the safety factor of the implant is>2,and the predicted percentage of effective bone growth area of the bone-implant interface reaches 97%.For further clinical application,PEEK implants were fabricated with fused filament fabrication(FFF)three-dimensional(3D)printing,and clinical outcomes demonstrated better bone repair efficacy and long-term stability of porous PEEK implants compared to solid PEEK ***,good osteointegration performance of 3D-printed porous PEEK implants was observed,with an average bone volume fraction>40%three months after *** conclusion,3D-printed porous PEEK implants have great potential for clinical application,with validated implantation safety and good osseointegration.

摘要：Tissue-engineered cartilage(TEC)remains a potential alternative for the repair of articular cartilage ***,there has been a significant different between the properties of TEC and those of natural *** have shown that mechanical stimulation such as compressive load can help regulate matrix remodelling in TEC,thus affecting its biomechanical ***,the influences of shear induced from the tissue fluid phase have not been well studied and may play an important role in tissue regeneration especially when integrated with the compressive ***,the aim of this study was to quantitatively investigate the effects of combined loading mechanisms on TEC in vitro.A bespoke biosimulator was built to incorporate the coupled motion of compression,friction and *** specimens,encapsulating freshly isolated rabbit chondrocytes in a hydrogel,were cultured within the biosimulator under various mechanical stimulations for 4 weeks,and the tissue activity,matrix contents and the mechanical properties were *** groups were categorized according to different mechanical stimulation combinations,including strain(5-20%at 5%intervals)and frequency(0.25 Hz,0.5 Hz,1 Hz),and the effects on tissue behaviour were *** the dynamic culture process,a combined load was applied to simulate the combined effects of compression,friction and shear on articular cartilage during human *** results indicated that a larger strain and higher frequency were more favourable for the specimen in terms of the cell proliferation and extracellular matrix ***,the combined mechanical stimulation was more beneficial to matrix remodelling than the single loading ***,the contribution of the combined mechanical stimulation to the engineered cartilaginous tissue matrix was not sufficient to impede biodegradation of the tissue with culture time.

摘要：新工科建设的深入推进,对高等院校工科专业人才培养和课程教学提出了新的挑战。文章围绕智能制造领域的机电一体化系统设计课程,分析了课程教学的现状和存在的问题,探讨了教学模式与方法转变的必要性,总结了多种教学模式改革策略,旨在提升课程教学质量,培养学生的创新能力和实践能力,以适应新形势下工科教育的需求。

摘要：目的以精准降低足底压力为目标,提出一种快捷、低成本的个性化糖尿病足部建模及鞋垫的设计方案。方法通过对标准足骨模型进行缩放的方法,构建患者足部有限元模型,分析足部生物力学,并根据鞋垫模量和足底压力数学映射模型,建立具有梯度模量的个性化鞋垫三维模型。利用3D打印技术进行鞋垫制造,并开展实验验证。结果采用缩放建模方法所建足部模型的有限元预测的相关力学指标与CT重建模型的结果基本接近,最大误差控制在15%以内。与穿戴普通鞋垫相比,使用个性化鞋垫后足底峰值压力有效降低约20%。该简化设计方案的时间和经济成本降低约90%。结论该糖尿病鞋垫设计方案缩短设计周期,其中制备的个性化鞋垫有效精准降低足底压力,降低足部溃疡的风险,为个性化糖尿病鞋垫的推广提供技术基础。

摘要：阐述利用既有线架设二线梁的架设特点、施工方法和工艺,并进行相应的工程造价分析,为我国铁路既有线增建二线的桥梁设计、施工和预算编制提供可借鉴的经验。

摘要：目的 对钛网及3D打印金属椎体替代物力学性能进行研究,为临床中人工椎体选择与结构优化设计提供指导。方法 通过压缩力学测试,对钛网及3D打印多孔型、桁架型与拓扑型椎体替代物的等效力学属性与结构破坏形式进行系统研究。结果 钛网等效弹性模量[(2 908.73±287.39) MPa]仅次于拓扑型椎体替代物,但其结构强度与稳定性较差,等效屈服强度[(46.61±4.85) MPa]高于多孔型椎体替代物,且在压缩中率先屈服;多孔型椎体替代物结构强度[(18.14±0.17)~(25.79±0.40) MPa]不足,难以满足脊柱重建力学要求;桁架型椎体替代物等效弹性模量[(2 477.86±55.19)~(2 620.08±194.36)MPa]与等效屈服强度[(77.61±0.50)~(88.42±1.07) MPa]良好但稳定性不足,在压缩过程中容易出现失稳现象;拓扑型椎体替代物具有最高的等效弹性模量[(3 746.28±183.80) MPa]与等效屈服强度[(177.43±3.82) MPa],可为人工椎体在体服役安全稳定提供更强保障。结论 拓扑优化方法可实现椎体替代物高强度、高稳定性设计,提供更大的设计空间与安全余量,为人工椎体轻量化与新材料设计提供更多可能。

摘要：本文结合某高速铁路特大桥跨越大型河流的主跨(32+48+32)m无砟轨道预应力混凝土双线连续梁工程,介绍了短线法胶结拼装施工方案,并就预拼装方案设计、成桥精度控制及胶结材料与工艺等方面进行分析研究.结果表明短线法胶结拼装施工技术相较于悬臂浇筑法有控制精度高、成桥线型好、能够明显缩短工期等优点,具有良好的应用前景.

摘要：目的针对传统颈椎融合器与患者解剖形貌匹配程度较低的临床问题,建立一款具备高度调节功能且外形与椎体相匹配的颈椎融合器,并对其生物力学性能进行评价。方法按照颈椎前路解压术(anterior cervical discectomy and fusion,ACDF)建立颈椎C4~5节段融合模型,模拟前屈、后伸、左右侧弯、左右旋转不同运动工况,计算融合器与椎体终板的应力。3D打印制备融合器后进行体外力学实验,探究融合器的安全性与稳定性。结果该融合器可保持融合C4~5节段颈椎活动度(range of motion,ROM)为1°~2.8°,降低至自然节段ROM的40%~80%。在体外压缩试验中,融合器屈服载荷为(2721.67±209)N,满足服役状态下生理载荷的最大需求。结论所设计的高度可调融合器显示出较优的生物力学性能,且可以减少手术中的选型步骤。

摘要：随着经济高速发展和城市人口日益增长,地下空间开发与利用呈规模化发展态势,大直径盾构隧道越来越多。盾构管片作为盾构隧道造价主要组成部分,管片定额较市场价高10%~25%,不能反映社会平均水平。为使定额能真实反映社会平均水平,基于技术测定法对管片预制进行实测研究,得出生产单方管片混凝土消耗量,并将测定价与现有定额价、市场价进行对比分析。结果表明:管片测定价与市场价差距基本在5%以内,满足了概算精度要求,建议对市政及铁路行业规范进行修编,使其能客观反映社会平均水平,以指导工程实践。

摘要：对山羊GBD-1进行载体构建,转到毕赤酵母中高效表达并对表达产物的生物学活性进行鉴定,为进一步研究防御素抗菌机理打下基础。根据Gen Bank中山羊β-防御素的CDS区序列,设计含有特殊酶切位点的引物扩增到目的片段,将该片段克隆到真核表达载体p PICZαA中,构建重组表达质粒p PICZαA/GBD-1,电转化到毕赤酵母中进行诱导表达。测序结果表明扩增的目的片段为114 bp,编码38个氨基酸,经Tricine-SDS-PAGE电泳验证在4.3 KD处有目的蛋白;作抑菌实验发现,重组蛋白对大肠杆菌、金黄色葡萄球菌有明显的抑菌效果。山羊防御素成功地在毕赤酵母中诱导表达,为进一步研究GBD-1的蛋白纯化以及抗菌机理打下基础,并为利用基因工程方法生产防御素提供理论依据。