MRFs(Myogenic regulatory factors,MRFs)家族包括肌分化因子Myo D、肌细胞生成素(myogenin)、生肌决定因子Myf5和Myf6,它们参与肌肉发生发育的各个环节。研究采用Real-time PCR方法研究了金定鸭胚胎期13、17、21、25和27日胚龄MRFs家...MRFs(Myogenic regulatory factors,MRFs)家族包括肌分化因子Myo D、肌细胞生成素(myogenin)、生肌决定因子Myf5和Myf6,它们参与肌肉发生发育的各个环节。研究采用Real-time PCR方法研究了金定鸭胚胎期13、17、21、25和27日胚龄MRFs家族基因在骨骼肌中的表达变化,并分析其表达变化与胚重、骨骼肌发育的相关性。金定鸭胚重及骨骼肌重发育模式显示胚重在胚胎期呈持续增加趋势,但胸肌在胚胎中后期显示出较腿肌滞后的增重变化。MRFs家族基因在胚胎期骨骼肌中均能检测到表达,Myo D m RNA在21日胚龄前腿肌中的表达量高于胸肌,而在胚胎发育后期(25及27日胚龄)胸肌中表达量渐渐高于腿肌。胸、腿肌中myogenin m RNA的表达与胚重、胸、腿肌发育重量变化均呈强的负线性相关。上述研究结果首次揭示了鸭胚胎期骨骼肌中MRFs家族基因表达具有显著的时空性,推测Myo D m RNA在胸、腿肌中的表达变化可能与胸、腿肌增重表型差异有关,研究结果为进一步深入研究MRFs家族基因在胚胎期骨骼肌发生过程及其调控机理中的功能提供一定的理论依据。展开更多
The aim of this study is to address the issues associated with traditional magnetorheological fluid(MRF)dampers,such as insufficient damping force after power failure and susceptibility to settlement.In order to achie...The aim of this study is to address the issues associated with traditional magnetorheological fluid(MRF)dampers,such as insufficient damping force after power failure and susceptibility to settlement.In order to achieve this,a bidirectional adjustable MRF damper was designed and developed.Magnetic field simulation analysis was conducted on the damper,along with simulation analysis on its dynamic characteristics.The dynamic characteristics were ultimately validated through experimental testing on the material testing machine,thereby corroborating the theoretical simulation results.Concurrently,this process generated valuable test data for subsequent implementation of the semi-active vibration control system.The simulation and test results demonstrate that the integrated permanent magnet effectively accomplishes bidirectional regulation.The magnetic induction intensity of the damping channel is 0.2 T in the absence of current,increases to 0.5 T when a maximum forward current of 4 A is applied,and becomes 0 T when a maximum reverse current of 3.8 A is applied.When the excitation amplitude is 8 mm and the frequency is 2 Hz,with the applied currents varying,the maximum damping force reaches 8 kN,while the minimum damping force measures at 511 N.Additionally,at zero current,the damping force stands at 2 kN,which aligns closely with simulation results.The present paper can serve as a valuable reference for the design and research of semi-active MRF dampers.展开更多
Myf5是生肌调节因子MRFs家族的重要成员,在肌细胞的增殖和发育过程中发挥着重要的调控作用。通过对心肌组织进行HE染色和免疫组化试验,观察心肌纤维细胞核的大小和数量、肌纤维体积和肌纤维之间的间隙变化,了解心肌组织不同发育阶段的...Myf5是生肌调节因子MRFs家族的重要成员,在肌细胞的增殖和发育过程中发挥着重要的调控作用。通过对心肌组织进行HE染色和免疫组化试验,观察心肌纤维细胞核的大小和数量、肌纤维体积和肌纤维之间的间隙变化,了解心肌组织不同发育阶段的显微结构,对比各组的阳性着色部位和着色程度的变化,从而对Myf5因子在不同发育阶段小鼠心肌组织的表达进行初步定性、定量和定位分析。并通过实时荧光定量PCR技术对小鼠的不同发育阶段中的心肌组织的Myf5基因表达做出准确的定量分析。结果表明,在小鼠心肌组织发育的不同阶段,Myf5均显示阳性,幼年鼠表达量最高;Myf5 m RNA表达量幼年鼠最高,性成熟鼠最低,呈现先降低后缓慢上升的趋势,并且幼年阶段与性成熟、体成熟阶段呈现极显著差异,与老年阶段无明显差异。研究表明,Myf5表达与小鼠心肌组织发育具有相关性,可进一步揭示Myf5在心脏发育的病理状况差异性和调控机制。展开更多
文摘MRFs(Myogenic regulatory factors,MRFs)家族包括肌分化因子Myo D、肌细胞生成素(myogenin)、生肌决定因子Myf5和Myf6,它们参与肌肉发生发育的各个环节。研究采用Real-time PCR方法研究了金定鸭胚胎期13、17、21、25和27日胚龄MRFs家族基因在骨骼肌中的表达变化,并分析其表达变化与胚重、骨骼肌发育的相关性。金定鸭胚重及骨骼肌重发育模式显示胚重在胚胎期呈持续增加趋势,但胸肌在胚胎中后期显示出较腿肌滞后的增重变化。MRFs家族基因在胚胎期骨骼肌中均能检测到表达,Myo D m RNA在21日胚龄前腿肌中的表达量高于胸肌,而在胚胎发育后期(25及27日胚龄)胸肌中表达量渐渐高于腿肌。胸、腿肌中myogenin m RNA的表达与胚重、胸、腿肌发育重量变化均呈强的负线性相关。上述研究结果首次揭示了鸭胚胎期骨骼肌中MRFs家族基因表达具有显著的时空性,推测Myo D m RNA在胸、腿肌中的表达变化可能与胸、腿肌增重表型差异有关,研究结果为进一步深入研究MRFs家族基因在胚胎期骨骼肌发生过程及其调控机理中的功能提供一定的理论依据。
文摘The aim of this study is to address the issues associated with traditional magnetorheological fluid(MRF)dampers,such as insufficient damping force after power failure and susceptibility to settlement.In order to achieve this,a bidirectional adjustable MRF damper was designed and developed.Magnetic field simulation analysis was conducted on the damper,along with simulation analysis on its dynamic characteristics.The dynamic characteristics were ultimately validated through experimental testing on the material testing machine,thereby corroborating the theoretical simulation results.Concurrently,this process generated valuable test data for subsequent implementation of the semi-active vibration control system.The simulation and test results demonstrate that the integrated permanent magnet effectively accomplishes bidirectional regulation.The magnetic induction intensity of the damping channel is 0.2 T in the absence of current,increases to 0.5 T when a maximum forward current of 4 A is applied,and becomes 0 T when a maximum reverse current of 3.8 A is applied.When the excitation amplitude is 8 mm and the frequency is 2 Hz,with the applied currents varying,the maximum damping force reaches 8 kN,while the minimum damping force measures at 511 N.Additionally,at zero current,the damping force stands at 2 kN,which aligns closely with simulation results.The present paper can serve as a valuable reference for the design and research of semi-active MRF dampers.
文摘Myf5是生肌调节因子MRFs家族的重要成员,在肌细胞的增殖和发育过程中发挥着重要的调控作用。通过对心肌组织进行HE染色和免疫组化试验,观察心肌纤维细胞核的大小和数量、肌纤维体积和肌纤维之间的间隙变化,了解心肌组织不同发育阶段的显微结构,对比各组的阳性着色部位和着色程度的变化,从而对Myf5因子在不同发育阶段小鼠心肌组织的表达进行初步定性、定量和定位分析。并通过实时荧光定量PCR技术对小鼠的不同发育阶段中的心肌组织的Myf5基因表达做出准确的定量分析。结果表明,在小鼠心肌组织发育的不同阶段,Myf5均显示阳性,幼年鼠表达量最高;Myf5 m RNA表达量幼年鼠最高,性成熟鼠最低,呈现先降低后缓慢上升的趋势,并且幼年阶段与性成熟、体成熟阶段呈现极显著差异,与老年阶段无明显差异。研究表明,Myf5表达与小鼠心肌组织发育具有相关性,可进一步揭示Myf5在心脏发育的病理状况差异性和调控机制。
