Actin-binding proteins sensitively mediate actin bundle stiffness

Surface as a carrier of information about the tribological process

The mechanisms of force generation and transference via microfilament networks are crucial to the understandings of mechanobiology of cellular processes in living cells. However, there exists an enormous challenge for all-atom physics simulation of real size microfilament networks due to scale limitation of molecular simulation techniques. Following biophysical investigations of constitutive relations between adjacent globular actin monomers on filamentous actin, a hierarchical multiscale model was developed to investigate the biomechanical properties of microfilament networks. This model was validated by previous experimental studies of axial tension and transverse vibration of single F-actin. The biomechanics of microfilament networks can be investigated at the scale of real eukaryotic cell size (10 μm). This multiscale approach provides a powerful modeling tool which can contribute to the understandings of actin-related cellular processes in living cells.

Hierarchical multiscale model for biomechanics analysis of microfilament networks

This paper presents a concurrent multiscale study for the deformation mechanism of mono-crystalline copper under dynamic uniaxial tension. The multiscale simulation is based on the coupled meshless and molecular dynamic (MD) method. Using it, the size of computational model can be extended to a large dimension (in micrometer) with an atomistic resolution. The pure MD simulation is difficult to reach this microscopic dimension because the number of atoms will be too large. In this study, it has been revealed that the deformation behavior and mechanism of the copper is sensitive to its size, geometry, and loading strain rate. In addition, the Young's modulus is found to be independent of the cross-sectional size and the strain rate range considered in this study. On the other hand, the yield stress decreases with specimen length and increases with the loading strain rate.

A multiscale deformation analysis for mono-crystalline copper under dynamic uniaxial tension

The mechanical properties of microfilament networks are systematically summarized at different special scales in this paper. We have presented the mechanical models of single microfilaments and microfilament networks at microscale. By adopting a coarse-grained simulation strategy, the mechanical stability of microfilaments related cellular structures are analysed. Structural analysis is conducted to microfilament networks to understand the stress relaxation under compression. The nanoscale molecular mechanisms of the microfilaments deformation is also summarized from the viewpoint of molecular dynamics simulation. This paper provides the fundaments of multiscale modelling framework for the mechanical behaviours simulation of hierarchical microfilament networks.

Mechanics of microfilaments networks : a cross-scales study

A theoretical model is developed for the analysis of piston secondary motion. Based on this model, the slap force of a specific L6 diesel engine was compared when considering different boundary conditions, such as lubricating oil on cylinder liner, surface roughness, deformation of cylinder liner and piston skirt. It is concluded that it is necessary to consider the secondary motion of piston in the analysis of the inner excitation for an internal combustion engine. A more comprehensive consideration of the boundary condition (i.e., more close to the actual condition) will lead to a smaller maximum slap force, and among all boundary conditions considered in this paper, the structural deformation of the piston skirt and cylinder liner is the most influential factor. The theoretical model developed and findings obtained in this study will benefit the future analysis and design of advanced internal combustion engine structures.

Bao Cheng Zhang

Papers

Mechanics of microfilaments networks : a cross-scales study

Impact of the Piston Secondary Motion on its Slap Force

Mechanics of microfilaments networks: A cross-scales study