目的采用微焦点断层扫描(Micro-CT)评价超声骨焊接技术应用过程中超声震荡产热作用下PDLLA材料对骨愈合性能的影响。方法选择SPF级雄性新西兰大白兔36只,随机分为超声骨焊接技术辅助PDLLA材料组(A组)、拧入技术辅助PDLLA材料组(B组)、...目的采用微焦点断层扫描(Micro-CT)评价超声骨焊接技术应用过程中超声震荡产热作用下PDLLA材料对骨愈合性能的影响。方法选择SPF级雄性新西兰大白兔36只,随机分为超声骨焊接技术辅助PDLLA材料组(A组)、拧入技术辅助PDLLA材料组(B组)、假手术组(C组)、空白对照组(D组),各9只。于术后4、8、12周取下颌骨标本,周围骨组织进行HE染色,观察各组植入钉周围情况。对术后4、8、12周的下颌骨大体标本拍摄Micro-CT图,使用VG Studio MAX软件进行三维重建,摆正数据样本,即颌骨颊侧造模处为轴向,动态分析植入钉体积、植入钉周围200μm环状区及骨缺损处的植入材料体积数、相对骨体积分数(BV/TV)、骨小梁厚度(Tb.Th)、骨小梁数(Tb.N)、骨小梁间隙(Tb.Sp)等骨愈合相关指标。结果HE染色结果显示,按3个时间可动态观察到A、B、C组骨缺损处骨性骨痂替代纤维性骨痂,形成类骨质,编织骨的过程符合正常骨损伤愈合的过程。Micro-CT结果显示,A、B组术后3个时间点的材料体积比较差异均无统计学意义(P>0.05);在3个时间点,4组植入钉周围200μm环状区中BV/TV、Tb.Th、Tb.N、Tb.Sp比较差异均无统计学意义(P>0.05);在骨缺损处,A、B、C组三个时间点BV/TV、Tb.Th、Tb.N、Tb.Sp比较差异无统计学意义(P>0.05);术后4周,与D组比较,A、B、C组BV/TV、Tb.Th、Tb.N、Tb.Sp差异有统计学意义(P<0.05);与C组比较,A、B组Tb.N差异有统计学意义(P<0.01)。术后8周,与D组比较,A、B、C组BV/TV、Tb.Th、Tb.N、Tb.Sp差异有统计学意义(P<0.05);术后12周,与D组比较,A、B、C组BV/TV、Tb.Th、Tb.Sp差异有统计学意义(P<0.05)。结论超声骨焊接技术其超声震荡产热作用下PDLLA材料对骨愈合性能无不良影响。展开更多
目的 采用定量非对称回波的最小二乘估算法迭代水脂分离序列(iterative decomposition of water and fat with echo asymmetry and least-squares estimation quantitation sequence, IDEAL-IQ)联合计算机显微断层扫描(micro computed t...目的 采用定量非对称回波的最小二乘估算法迭代水脂分离序列(iterative decomposition of water and fat with echo asymmetry and least-squares estimation quantitation sequence, IDEAL-IQ)联合计算机显微断层扫描(micro computed tomography, Micro-CT)技术评估兔1型糖尿病腰椎骨髓脂肪含量和骨小梁微结构相关性。材料与方法 将16只雄性日本大耳白兔随机分为糖尿病组(n=8)和对照组(n=8),糖尿病组采用四氧嘧啶造模。在造模成功后第0、4、8、12、16周通过IDEAL-IQ定量评估兔腰椎骨髓脂肪含量。在第16周采用Micro-CT及组织病理学检查对兔腰椎骨小梁微结构进行定量评估。不同时间点腰椎IDEAL-IQ脂肪分数差异比较采用重复测量方差分析;同一时间点组间脂肪分数、Micro-CT骨小梁形态计量学参数、组织病理学参数差异比较采用独立样t检验或Mann-Whitney U检验;采用Pearson相关系数评估骨髓脂肪分数与骨小梁形态计量学参数、组织病理学参数相关性。结果 糖尿病组骨髓脂肪含量随时间变化呈上升趋势,且差异存在统计学意义(P<0.05),而对照组各时间点脂肪含量差异无统计学意义(P>0.05);糖尿病组与对照组腰椎骨髓脂肪分数在第16周差异有统计学意义(59.987±4.859 vs. 51.015±8.469,P<0.05);第16周糖尿病组骨体积、总表面积、骨表面积、骨表面积总体积比、骨小梁数量均低于对照组,而骨小梁分离度高于对照组,差异有统计学意义(P<0.05);组织病理学结果显示,与对照组相比,第16周糖尿病兔腰椎骨髓脂肪细胞数量(32.875±11.051 vs. 71.667±13.125, P<0.01)增加,而骨小梁数量(11.375±1.506vs.4.333±1.211, P<0.01)与骨小梁面积(0.927±0.071vs.0.312±0.100, P<0.01)明显减少;IDEAL-IQ脂肪分数与组织病理学脂肪细胞计数呈正相关关系(r=0.539 95%CI:0.012~0.832),与骨小梁模式因子、骨小梁结构模型指数、骨小梁分离度呈轻中度正相关关系,与骨矿物质密度、总体积、骨体积、骨体积分数、总表面积、骨表面积、骨表面积体积比、骨表面积总体积比、骨小梁数量呈轻至中度负相关关系。结论 1型糖尿病腰椎骨髓脂肪含量与骨小梁微结构变化存在相关性,IDEAL-IQ联合Micro-CT的多模态定量影像技术有望为1型糖尿病提供全面的骨髓微环境评估策略。展开更多
The mesomechanics of geotechnical materials are closely related to the macromechanical properties,especially the mesoscale evolution of shear bands,which is helpful for understanding the failure mechanism of geotechni...The mesomechanics of geotechnical materials are closely related to the macromechanical properties,especially the mesoscale evolution of shear bands,which is helpful for understanding the failure mechanism of geotechnical materials.However,there is lack of effective quantitative analysis method for the complex evolution mechanism of threedimensional shear bands.In this work,we used X-ray computed tomography(CT)to reconstruct volume images and used the digital volume correlation(DVC)method to calculate the three-dimensional strain fields of granite residual soil samples at different loading stages.The trend of the failure surface of the shear bands was obtained by the planar fitting method,and the connectivity index was constructed according to the projection characteristics of the shear bands on the failure trend surface.The results support the following findings:the connectivity index of the shear band increases rapidly and then slowly with increasing axial strain,which is characterized by a near'S'curve.As the stress reaches the peak value,the connectivity index of the shear bands almost exceeds 0.7.The contribution of the new shear band volume to the connectivity of the shear bands becomes increasingly small with increasing axial loading.Affected by quartz grains and stress at the initial stage,the dip angle gradually and finally approaches the included angle of the maximum shear stress from the discrete state with increasing axial loading.The tendency and dip angle of the resulting shear bands are dynamic,and the tendency slightly deflects with increasing loading.展开更多
文摘目的采用微焦点断层扫描(Micro-CT)评价超声骨焊接技术应用过程中超声震荡产热作用下PDLLA材料对骨愈合性能的影响。方法选择SPF级雄性新西兰大白兔36只,随机分为超声骨焊接技术辅助PDLLA材料组(A组)、拧入技术辅助PDLLA材料组(B组)、假手术组(C组)、空白对照组(D组),各9只。于术后4、8、12周取下颌骨标本,周围骨组织进行HE染色,观察各组植入钉周围情况。对术后4、8、12周的下颌骨大体标本拍摄Micro-CT图,使用VG Studio MAX软件进行三维重建,摆正数据样本,即颌骨颊侧造模处为轴向,动态分析植入钉体积、植入钉周围200μm环状区及骨缺损处的植入材料体积数、相对骨体积分数(BV/TV)、骨小梁厚度(Tb.Th)、骨小梁数(Tb.N)、骨小梁间隙(Tb.Sp)等骨愈合相关指标。结果HE染色结果显示,按3个时间可动态观察到A、B、C组骨缺损处骨性骨痂替代纤维性骨痂,形成类骨质,编织骨的过程符合正常骨损伤愈合的过程。Micro-CT结果显示,A、B组术后3个时间点的材料体积比较差异均无统计学意义(P>0.05);在3个时间点,4组植入钉周围200μm环状区中BV/TV、Tb.Th、Tb.N、Tb.Sp比较差异均无统计学意义(P>0.05);在骨缺损处,A、B、C组三个时间点BV/TV、Tb.Th、Tb.N、Tb.Sp比较差异无统计学意义(P>0.05);术后4周,与D组比较,A、B、C组BV/TV、Tb.Th、Tb.N、Tb.Sp差异有统计学意义(P<0.05);与C组比较,A、B组Tb.N差异有统计学意义(P<0.01)。术后8周,与D组比较,A、B、C组BV/TV、Tb.Th、Tb.N、Tb.Sp差异有统计学意义(P<0.05);术后12周,与D组比较,A、B、C组BV/TV、Tb.Th、Tb.Sp差异有统计学意义(P<0.05)。结论超声骨焊接技术其超声震荡产热作用下PDLLA材料对骨愈合性能无不良影响。
文摘目的 采用定量非对称回波的最小二乘估算法迭代水脂分离序列(iterative decomposition of water and fat with echo asymmetry and least-squares estimation quantitation sequence, IDEAL-IQ)联合计算机显微断层扫描(micro computed tomography, Micro-CT)技术评估兔1型糖尿病腰椎骨髓脂肪含量和骨小梁微结构相关性。材料与方法 将16只雄性日本大耳白兔随机分为糖尿病组(n=8)和对照组(n=8),糖尿病组采用四氧嘧啶造模。在造模成功后第0、4、8、12、16周通过IDEAL-IQ定量评估兔腰椎骨髓脂肪含量。在第16周采用Micro-CT及组织病理学检查对兔腰椎骨小梁微结构进行定量评估。不同时间点腰椎IDEAL-IQ脂肪分数差异比较采用重复测量方差分析;同一时间点组间脂肪分数、Micro-CT骨小梁形态计量学参数、组织病理学参数差异比较采用独立样t检验或Mann-Whitney U检验;采用Pearson相关系数评估骨髓脂肪分数与骨小梁形态计量学参数、组织病理学参数相关性。结果 糖尿病组骨髓脂肪含量随时间变化呈上升趋势,且差异存在统计学意义(P<0.05),而对照组各时间点脂肪含量差异无统计学意义(P>0.05);糖尿病组与对照组腰椎骨髓脂肪分数在第16周差异有统计学意义(59.987±4.859 vs. 51.015±8.469,P<0.05);第16周糖尿病组骨体积、总表面积、骨表面积、骨表面积总体积比、骨小梁数量均低于对照组,而骨小梁分离度高于对照组,差异有统计学意义(P<0.05);组织病理学结果显示,与对照组相比,第16周糖尿病兔腰椎骨髓脂肪细胞数量(32.875±11.051 vs. 71.667±13.125, P<0.01)增加,而骨小梁数量(11.375±1.506vs.4.333±1.211, P<0.01)与骨小梁面积(0.927±0.071vs.0.312±0.100, P<0.01)明显减少;IDEAL-IQ脂肪分数与组织病理学脂肪细胞计数呈正相关关系(r=0.539 95%CI:0.012~0.832),与骨小梁模式因子、骨小梁结构模型指数、骨小梁分离度呈轻中度正相关关系,与骨矿物质密度、总体积、骨体积、骨体积分数、总表面积、骨表面积、骨表面积体积比、骨表面积总体积比、骨小梁数量呈轻至中度负相关关系。结论 1型糖尿病腰椎骨髓脂肪含量与骨小梁微结构变化存在相关性,IDEAL-IQ联合Micro-CT的多模态定量影像技术有望为1型糖尿病提供全面的骨髓微环境评估策略。
基金supported by the Building Fund for the Academic Innovation Team of Shantou University (CN)(NTF21017)the Special Fund for Science and Technology of Guangdong Province in2021 (STKJ2021181)the National Natural Science Foundation of China (Grant nos.12272394)
文摘The mesomechanics of geotechnical materials are closely related to the macromechanical properties,especially the mesoscale evolution of shear bands,which is helpful for understanding the failure mechanism of geotechnical materials.However,there is lack of effective quantitative analysis method for the complex evolution mechanism of threedimensional shear bands.In this work,we used X-ray computed tomography(CT)to reconstruct volume images and used the digital volume correlation(DVC)method to calculate the three-dimensional strain fields of granite residual soil samples at different loading stages.The trend of the failure surface of the shear bands was obtained by the planar fitting method,and the connectivity index was constructed according to the projection characteristics of the shear bands on the failure trend surface.The results support the following findings:the connectivity index of the shear band increases rapidly and then slowly with increasing axial strain,which is characterized by a near'S'curve.As the stress reaches the peak value,the connectivity index of the shear bands almost exceeds 0.7.The contribution of the new shear band volume to the connectivity of the shear bands becomes increasingly small with increasing axial loading.Affected by quartz grains and stress at the initial stage,the dip angle gradually and finally approaches the included angle of the maximum shear stress from the discrete state with increasing axial loading.The tendency and dip angle of the resulting shear bands are dynamic,and the tendency slightly deflects with increasing loading.
