论文标题
轴突的高visCoalastic 3D响应，轴突在脑白质中反复拉伸负荷
Hyper-viscoelastic 3D response of axons subjected to repeated tensile loads in brain white matter
论文作者
论文摘要
开发了一种新的有限元方法（FEM），以研究在纯粹的非携带运动学边界条件下进行谐波单轴拉伸时，嵌入了额外细胞基质（ECM）的轴突的机械响应。所提出的建模方法结合了超弹性（例如Ogden模型）和时间/频域粘弹性组成型模型，以评估50Hz谐波拉伸下参数变化的少突胶质细胞 - X肌关系的影响。杂化高易度弹性材料（HVE）模型可以分析重复的单轴负载，以在白质中的压力传播和损伤积累中分析。 在拟议的FEM中，通过弹簧式仪表板模型描绘了与轴突的少突胶质细胞连接。这种束缚技术促进了在各个位置的接触定义，参数化连接点和连接轮毂的刚度变化。提出了来自各个位置的轴突的单个少突胶质细胞的本土Fe子模型构型的结果。根平方偏差（RMSD）是在应力 - 应变图之间计算出的，以描绘机械响应的趋势。稳态动态（SSD）模拟显示轴突中的应力松弛。使用Prony系列-HVE模型在重复载荷下逐渐轴突软化。代表性的von-mises应力图表明，起伏的轴突沿曲折路径弯曲应力，表明由于重复菌株而导致损害积累和疲劳失败的敏感性更大。
A novel finite element method (FEM) is developed to study mechanical response of axons embedded in extra cellular matrix (ECM) when subjected to harmonic uniaxial stretch under purely non-affine kinematic boundary conditions. The proposed modeling approach combines hyper-elastic (such as Ogden model) and time/frequency domain viscoelastic constitutive models to evaluate the effect of parametrically varying oligodendrocyte-axon tethering under harmonic stretch at 50Hz. A hybrid hyper-viscoelastic material (HVE) model enabled the analysis of repeated uniaxial load on stress propagation and damage accumulation in white matter. In the proposed FEM, oligodendrocyte connections to axons are depicted via a spring-dashpot model. This tethering technique facilitates contact definition at various locations, parameterizes connection points and varies stiffness of connection hubs. Results from a home-grown FE submodel configuration of a single oligodendrocyte tethered to axons at various locations are presented. Root mean square deviation (RMSD) are computed between stress-strain plots to depict trends in mechanical response. Steady-state dynamic (SSD) simulations show stress relaxation in axons. Gradual axonal softening under repetitive loads is illustrated employing Prony series - HVE models. Representative von-Mises stress plots indicate that undulated axons experience bending stresses along their tortuous path, suggesting greater susceptibility to damage accumulation and fatigue failure due to repeated strains.
