Effects Of Axial Loading And Surface Effect On The Coupling Vibration Of Bioliquid-fillled Nonlocal Microtubules Embedded In The Medium

Microtubules (MTs) are cylindrical protein polymers with a diameterof about25nm, interconnected by cross bridging proteins, whichstructurally and dynamically organize functional activities in living cells,including synaptic regulation inside of the brain's neurons. They are themost prominent feature of the cytoskeleton. Microtubules exist in allmammalian cells, thus the study of microtubules has universality and greatsignificance. This article considers the coupling vibration of a fluid-filledmicrotubule embedded in the elastic medium on the basis of existingdocuments. In this paper, the influent of initial axial loading, the surfaceeffect, the small scale effect, the effects of constrained stiffness ofsurrounding bio-medium, and the influence of bio-liquid density on thecoupling vibration of fluid-filled microtubules are developed. Detailednumerical analyses about the influence of the fluid density, the nonlocalparameter and initial stress on the system's frequency are conducted, andthe comparing results between various conditions are drawn. It is hopedthat the results in the manuscript may provide reference information forbiomedical clinical applications. Erigen's nonlocal elastic theory is utilizedto describe the nano-scale characteristic of the microtubule. And Winkler'smodel is utilized to describe the radial force caused by the surroundingfilament network. Results show that the influence of the additionalparameters on the coupled vibration frequency of bio-liquid-filled MTgradually decreases as the bio-liquid density in microtubule increases. For a nonlocal microtubule embedded in the medium: the influence of surfaceeffect on the microtubule's vibration frequency decreases as the surfaceelasticity modulus increases, and increases as the residual surface tensionincreases; the influence of initial axial loading on the microtubule'svibration frequency increases as the initial axial loading increases.Meanwhile, the influence of surface effect is greater than the initial axialloading. The new investigation results may be used as a useful referencefor the ultrasonic examine of nano-microtubule organization under initialaxial loading and some biomedical clinical applications.