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海港城工程模板脚手架关键施工技术
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作者 牛潮 黄小逸 《施工技术》 CAS 2019年第16期125-129,共5页
结合中山市小榄海港城商业发展项目,详细介绍了集成附着式升降脚手架技术、组合铝合金模板施工技术、盘销式钢管脚手架技术在该工程中的应用。同时,通过应用铝合金模板与木模板结合施工技术、铝合金模板与升降脚手架穿插施工技术缩短了... 结合中山市小榄海港城商业发展项目,详细介绍了集成附着式升降脚手架技术、组合铝合金模板施工技术、盘销式钢管脚手架技术在该工程中的应用。同时,通过应用铝合金模板与木模板结合施工技术、铝合金模板与升降脚手架穿插施工技术缩短了施工工期并节约了成本,实现了高层建筑脚手架工艺的模块化、工具化和标准化、机械化施工。 展开更多
关键词 脚手架 附着式升降脚手架 铝合金模板 盘销式钢管脚手架 施工技术
Additive manufacturing of bone scaffolds 预览
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作者 Youwen Yang Guoyong Wang +4 位作者 Huixin Liang Chengde Gao Shuping Peng Lida Shen Cijun Shuai 《国际生物打印期刊》 2019年第1期84-108,共25页
Additive manufacturing(AM)can obtain not only customized external shape but also porous internal structure for scaffolds,both of which are of great importance for repairing large segmental bone defects.The scaffold fa... Additive manufacturing(AM)can obtain not only customized external shape but also porous internal structure for scaffolds,both of which are of great importance for repairing large segmental bone defects.The scaffold fabrication process generally involves scaffold design,AM,and post-treatments.Thus,this article firstly reviews the state-of-the-art of scaffold design,including computer-aided design,reverse modeling,topology optimization,and mathematical modeling.In addition,the current characteristics of several typical AM techniques,including selective laser sintering,fused deposition modeling(FDM),and electron beam melting(EBM),especially their advantages and limitations are presented.In particular,selective laser sintering is able to obtain scaffolds with nanoscale grains,due to its high heating rate and a short holding time.However,this character usually results in insufficient densification.FDM can fabricate scaffolds with a relative high accuracy of pore structure but with a relative low mechanical strength.EBM with a high beam-material coupling efficiency can process high melting point metals,but it exhibits a low-resolution and poor surface quality.Furthermore,the common post-treatments,with main focus on heat and surface treatments,which are applied to improve the comprehensive performance are also discussed.Finally,this review also discusses the future directions for AM scaffolds for bone tissue engineering. 展开更多
关键词 Additive manufacturing bone scaffolds scaffolds design post-treatments
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Collagen-chitosan scaffold impregnated with bone marrow mesenchymal stem cells for treatment of traumatic brain injury 预览
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作者 Feng Yan Ming Li +7 位作者 Hong-Qi Zhang Gui-Lin Li Yang Hua Ying Shen Xun-Ming Ji Chuan-Jie Wu Hong An Ming Ren 《中国神经再生研究:英文版》 SCIE CAS CSCD 2019年第10期1780-1786,共7页
Combinations of biomaterials and cells can effectively target delivery of cells or other therapeutic factors to the brain to rebuild damaged nerve pathways after brain injury.Porous collagen-chitosan scaffolds were pr... Combinations of biomaterials and cells can effectively target delivery of cells or other therapeutic factors to the brain to rebuild damaged nerve pathways after brain injury.Porous collagen-chitosan scaffolds were prepared by a freeze-drying method based on brain tissue engineering.The scaffolds were impregnated with rat bone marrow mesenchymal stem cells.A traumatic brain injury rat model was established using the 300 g weight free fall impact method.Bone marrow mesenchymal stem cells/collagen-chitosan scaffolds were implanted into the injured brain.Modified neurological severity scores were used to assess the recovery of neurological function.The Morris water maze was employed to determine spatial learning and memory abilities.Hematoxylin-eosin staining was performed to measure pathological changes in brain tissue.Immunohistochemistry was performed for vascular endothelial growth factor and for 5-bromo-2-deoxyuridine(BrdU)/neuron specific enolase and BrdU/glial fibrillary acidic protein.Our results demonstrated that the transplantation of bone marrow mesenchymal stem cells and collagen-chitosan scaffolds to traumatic brain injury rats remarkably reduced modified neurological severity scores,shortened the average latency of the Morris water maze,increased the number of platform crossings,diminished the degeneration of damaged brain tissue,and increased the positive reaction of vascular endothelial growth factor in the transplantation and surrounding areas.At 14 days after transplantation,increased BrdU/glial fibrillary acidic protein expression and decreased BrdU/neuron specific enolase expression were observed in bone marrow mesenchymal stem cells in the injured area.The therapeutic effect of bone marrow mesenchymal stem cells and collagen-chitosan scaffolds was superior to stereotactic injection of bone marrow mesenchymal stem cells alone.To test the biocompatibility and immunogenicity of bone marrow mesenchymal stem cells and collagen-chitosan scaffolds,immunosuppressive cyclosporine was intravenously inject 展开更多
关键词 nerve REGENERATION STEM CELLS COLLAGEN chitosan scaffolds traumatic BRAIN injury bone MARROW mesenchymal STEM CELLS BRAIN tissue engineering neural REGENERATION
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熔体静电纺丝直写技术在组织工程中的应用进展 预览
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作者 姚子琪 马东明 +4 位作者 雷文龙 焦志伟 李好义 徐小东 张有忱 《化工进展》 EI CAS CSCD 北大核心 2019年第8期3756-3762,共7页
熔体静电纺丝直写技术以其纤维直径、沉积形貌可控性高及无溶剂残留等优势,为高强度复杂形貌可控仿生组织工程(TE)支架的制备提供了巨大的空间,成为近年来的研究热点。本文首先简述了熔体静电纺丝直写技术相对于各类其他TE支架制备方法... 熔体静电纺丝直写技术以其纤维直径、沉积形貌可控性高及无溶剂残留等优势,为高强度复杂形貌可控仿生组织工程(TE)支架的制备提供了巨大的空间,成为近年来的研究热点。本文首先简述了熔体静电纺丝直写技术相对于各类其他TE支架制备方法的优势;其次从工艺调控方面综述了熔体静电纺丝直写技术的工艺研究进展,并总结了实现复杂可控形貌TE支架的调控方法;随后从支架材料、形貌表征和细胞培养效果等方面综述了熔体静电纺丝直写技术的TE应用进展,并概括了该技术制备的TE拓扑结构支架的种类及特点;最后指出熔体静电纺丝直写技术具有广阔的研究前景,且该技术应以制备仿生、材料多样化以及复合支架为研究重点。 展开更多
关键词 熔体静电纺丝 直写技术 纤维 组织工程 支架
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Mechanical properties of AM Ti6Al4V porous scaffolds with various cell structures
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作者 Hua-De Zheng Li-Li Liu +2 位作者 Chun-Lin Deng Zhi-Feng Shi Cheng-Yun Ning 《稀有金属:英文版》 SCIE EI CAS CSCD 2019年第6期561-570,共10页
Porous scaffolds as succedaneum of natural bone were investigated and applied in medical field.In this work, we carried out studies on mechanical properties of solid parts and porous scaffolds obtained by additive man... Porous scaffolds as succedaneum of natural bone were investigated and applied in medical field.In this work, we carried out studies on mechanical properties of solid parts and porous scaffolds obtained by additive manufacturing(AM) technique.It is found that productions of AM process have a higher yield strength and higher microhardness compared to commercial Ti6Al4V.Roughened surface was observed for layer-by-layer process of AM and sticking of powder particles.The machining accuracy is affected by both dimensions and angles.Meanwhile, mechanical properties of porous scaffolds are influenced by machining accuracy and microdefects.In addition, the unit cell structures also impact the mechanical properties of porous scaffolds in terms of elastic modulus, yield strength and failure mode.Overall,considering the mechanical properties and biological properties, scaffolds with cube(CB) crystal cells are the best choice in our study. 展开更多
关键词 TI6AL4V POROUS scaffolds AM MECHANICAL PROPERTY
骨软骨组织工程研究进展
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作者 兰伟伟 陈维毅(综述) 黄棣(审校) 《生物医学工程学杂志》 EI CAS CSCD 北大核心 2019年第3期504-510,共7页
骨软骨损伤是临床上常见的关节疾病。由于骨软骨界面的复杂性和软骨自我修复能力匮乏等因素,针对骨软骨损伤的临床治疗局限性较大。组织工程的提出,为骨软骨损伤同步修复提供了新的治疗方式。本文就骨软骨组织工程的三个方面进行综述介... 骨软骨损伤是临床上常见的关节疾病。由于骨软骨界面的复杂性和软骨自我修复能力匮乏等因素,针对骨软骨损伤的临床治疗局限性较大。组织工程的提出,为骨软骨损伤同步修复提供了新的治疗方式。本文就骨软骨组织工程的三个方面进行综述介绍,它们分别是:种子细胞来源以及培养方式、生长因子的调控以及协同作用、细胞支架的组成类型,文中着重探讨骨软骨修复支架的现状和研究进展,最终期待通过本文综述,可为骨软骨组织工程的进一步发展提供参考。 展开更多
关键词 骨软骨缺损 组织工程 种子细胞 细胞因子 支架
3D生物打印支架的微孔结构与孔隙率的研究进展 预览 被引量:1
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作者 田银平 刘湘宁 +2 位作者 姚洁 谭俊龙 叶辉生 《分子影像学杂志》 2019年第1期81-86,共6页
近年来,3D生物打印受到越来越多研究者的关注,该技术弥补了传统组织工程技术的局限性,它可打印出精准、个性化的支架结构,并可以任意地设计形状、尺寸、孔的结构和孔隙率等。3D生物打印支架在组织工程应用中通常提供结构支撑和适宜的微... 近年来,3D生物打印受到越来越多研究者的关注,该技术弥补了传统组织工程技术的局限性,它可打印出精准、个性化的支架结构,并可以任意地设计形状、尺寸、孔的结构和孔隙率等。3D生物打印支架在组织工程应用中通常提供结构支撑和适宜的微环境以支持细胞行为,而支架的微孔结构及孔隙率对细胞的行为和健康至关重要,所以3D生物打印支架应该是具有高度多孔和互连的孔网络结构,以促进营养运输、废物排泄和细胞生长增殖分化。本文将综述从无生命到有生命的3D生物打印支架材料和打印方式,以及着重介绍支架的微孔结构及孔隙率相关研究。 展开更多
关键词 3D生物打印 支架 微孔结构 孔隙率
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3D打印技术在牙周组织再生支架制备中的应用 预览
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作者 许雄程 钟泉 骆凯 《口腔疾病防治》 2019年第3期189-193,共5页
如何获得理想的牙周组织的再生修复依然是当前牙周炎临床治疗的挑战。3D打印技术是基于计算机辅助设计,经逐层叠加制作特定三维形态的材料,现已应用于牙周组织再生治疗,为实现理想的牙周再生带来希望。本文拟就3D打印技术在牙周组织再... 如何获得理想的牙周组织的再生修复依然是当前牙周炎临床治疗的挑战。3D打印技术是基于计算机辅助设计,经逐层叠加制作特定三维形态的材料,现已应用于牙周组织再生治疗,为实现理想的牙周再生带来希望。本文拟就3D打印技术在牙周组织再生领域中的应用进行综述。文献复习结果表明,3D打印技术可预先通过计算机软件设计三维结构,生产出具有特定三维结构的材料;3D打印技术主要包括选择性激光烧结、选择性激光熔化、挤压成形打印和3D生物打印;当前通过3D打印技术制备的支架材料有陶瓷材料、高分子材料和金属;高分子材料因其可调节性大而被广泛研究,而3D打印的个性化钛网已被应用于临床;利用3D打印技术制备的多相材料在动物试验上已可实现牙周组织再生,但应用于牙周炎患者疗效欠佳。3D打印牙周组织再生复合支架有待于进一步的研究。 展开更多
关键词 牙周炎 3D打印 牙周组织再生 支架材料 选择性激光烧结 选择性激光熔化
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Role and prospects of regenerative biomaterials in the repair of spinal cord injury 预览
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作者 Shuo Liu Yuan-Yuan Xie Bin Wang 《中国神经再生研究:英文版》 SCIE CAS CSCD 2019年第8期1352-1363,共12页
Axonal junction defects and an inhibitory environment after spinal cord injury seriously hinder the regeneration of damaged tissues and neuronal functions. At the site of spinal cord injury, regenerative biomaterials ... Axonal junction defects and an inhibitory environment after spinal cord injury seriously hinder the regeneration of damaged tissues and neuronal functions. At the site of spinal cord injury, regenerative biomaterials can fill cavities, deliver curative drugs, and provide adsorption sites for transplanted or host cells. Some regenerative biomaterials can also inhibit apoptosis, inflammation and glial scar formation, or further promote neurogenesis, axonal growth and angiogenesis. This review summarized a variety of biomaterial scaffolds made of natural, synthetic, and combined materials applied to spinal cord injury repair. Although these biomaterial scaffolds have shown a certain therapeutic effect in spinal cord injury repair, there are still many problems to be resolved, such as product standards and material safety and effectiveness. 展开更多
关键词 nerve REGENERATION spinal cord injury REGENERATIVE BIOMATERIALS scaffolds tissue engineering REGENERATION transplantation combination functional recovery REPAIR strategy MICROENVIRONMENT neural REGENERATION
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援柬埔寨体育场多倾角环柱与双曲环梁支撑体系施工技术
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作者 张志平 郭亮亮 +2 位作者 王群清 曹江 贾红学 《施工技术》 CAS 2019年第15期122-125,共4页
援柬埔寨体育场四周设有多倾角、大截面环柱和双曲环梁,根据结构特点及施工现场实际情况,支撑体系采用'环梁扣件式满堂脚手架+环柱操作架+钢管支撑'的形式。工程实践及有限元分析结果表明,应用该支撑体系可在保证安全的前提下... 援柬埔寨体育场四周设有多倾角、大截面环柱和双曲环梁,根据结构特点及施工现场实际情况,支撑体系采用'环梁扣件式满堂脚手架+环柱操作架+钢管支撑'的形式。工程实践及有限元分析结果表明,应用该支撑体系可在保证安全的前提下加快环梁、环柱施工效率,降低措施费用,提高支撑体系周转率,达到降本增效的目的,实现工程预期目标。 展开更多
关键词 体育场 脚手架 多倾角环柱 双曲环梁 支撑 施工技术
The effect of pore size and porosity of Ti6Al4V scaffolds on MC3T3-E1 cells and tissue in rabbits
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作者 LUAN HuiQin WANG LiTing +4 位作者 REN WeiYan CHU Zhao Wei HUANG YunFei LU ChengLin FAN YuBo 《中国科学:技术科学英文版》 SCIE EI CAS CSCD 2019年第7期1160-1168,共9页
Electron beam melting(EBM) allows the fabrication of specific porous titanium implants, whereas their in vitro and in vivo biological performance should be further investigated. In this study, we examined the porous T... Electron beam melting(EBM) allows the fabrication of specific porous titanium implants, whereas their in vitro and in vivo biological performance should be further investigated. In this study, we examined the porous Ti6 Al4 V scaffolds(low, 334.1 μm pore size with 55.4% porosity;middle, 383.2 μm pore size with 65.2% porosity;and high, 401.6 μm pore size with 78.1%porosity) fabricated through EBM. The structural characterization and mechanical properties of porous Ti6 Al4 V scaffolds were measured through micro-computed tomography(micro-CT), scanning electron microscopy, and a material testing system.MC3 T3-E1 cells were used to assess the proliferation and differentiation of the cells on different scaffolds at day 7 and day 14 based on the expression levels of genes, including alkaline phosphatase, bone morphogenetic protein-2, osteopontin and runtrelated transcription factor-2. Rabbits with distal femoral defects were utilized to evaluate bone ingrowth in the porous titanium.All of the samples were subjected to micro-CT and histological analysis after 12 weeks. Results showed that compressive Young’s modulus of 0.3–1.1 GPa was similar to the trabecular bone. The three types of porous Ti6 Al4 V scaffolds were inclined to promote cell proliferation, whereas cell differentiation and bone ingrowth into the porous scaffolds were biased to the porous titanium with relatively large pores and porosity(middle and high). This study implied that the present porous implant design,which had the combined advantages of different pore sizes and porosity, might be meaningful and promising for trabecular bone defect restoration. 展开更多
关键词 PORE size POROSITY porous titanium alloy scaffolds OSTEOGENESIS bone DEFECT
Assignment of unanchored scaffolds in genome of Brassica napus by RNA-seq analysis in a complete set of Brassica rapa-Brassica oleracea monosomic addition lines 预览
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作者 HUO Dong-ao ZHU Bin +3 位作者 TIAN Gui-fu DU Xu-ye GUO Juan CAI Meng-xian 《农业科学学报:英文版》 SCIE CAS CSCD 2019年第7期1541-1546,共6页
The economically valuable oil crop Brassica napus(AACC,2 n=38),which arose from interspecific hybridization between the diploid ancestors Brassica rapa(AA,2 n=20) and Brassica oleracea(CC,2 n=18),has a complex genome.... The economically valuable oil crop Brassica napus(AACC,2 n=38),which arose from interspecific hybridization between the diploid ancestors Brassica rapa(AA,2 n=20) and Brassica oleracea(CC,2 n=18),has a complex genome.More than 10% of the assembled sequences,most of which belong to the C subgenome,have not been anchored to the corresponding chromosome.Previously,a complete set of monosomic alien addition lines(MAALs,C1–C9) with each of the nine C-subgenome chromosomes added to the extracted A subgenome was obtained from the allotetraploid B.napus donor Oro,after the ancestral B.rapa(RBR Oro) genome was restored.These MAALs effectively reduced the complexity of the B.napus genome.Here,we determined the expression values of genes on unanchored scaffolds in the MAALs and RBR Oro.Then,multiple comparisons of these gene expression values were used to determine the affiliations of the nonanchored scaffolds on which the genes were located.In total,54.68%(44.11 Mb) of the 80.67 Mb of non-anchored scaffolds belonging to the C subgenome were assigned to corresponding C chromosomes.This work highlights the potential value of these MAALs in improving the genome quality of B.napus. 展开更多
关键词 Brassica NAPUS GENOME sequence RNA-SEQ monosomic ALIEN addition lines scaffolds
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脱细胞脂肪组织基质材料研究进展
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作者 郭潇 曾昂 朱琳 《中华整形外科杂志》 CAS CSCD 北大核心 2019年第1期89-92,共4页
细胞外基质在细胞增殖、分化及基因表达等方面发挥重要的调控作用,且与天然组织三维结构相似,被广泛应用于组织工程研究领域。脱细胞脂肪组织基质是脂肪来源的细胞外基质,其来源广泛、获取简单,且具有促脂肪新生和促血管新生作用,可为... 细胞外基质在细胞增殖、分化及基因表达等方面发挥重要的调控作用,且与天然组织三维结构相似,被广泛应用于组织工程研究领域。脱细胞脂肪组织基质是脂肪来源的细胞外基质,其来源广泛、获取简单,且具有促脂肪新生和促血管新生作用,可为脂肪干细胞提供良好的微环境,为软组织缺损