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Updated: Jun 1, 2026

Method to Measure Tone of Axial and Proximal Muscle
Published on: December 14, 2011
Axial thermal rotation of slender rods
Dichuan Li1, Nikta Fakhri, Matteo Pasquali
1Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005, USA.
Abstract:
Axial rotational diffusion of rodlike polymers is important in processes such as microtubule filament sliding and flagella beating. By imaging the motion of small kinks along the backbone of chains of DNA-linked colloids, we produce a direct and systematic measurement of axial rotational diffusivity of rods both in bulk solution and near a wall. The measured diffusivities decrease linearly with the chain length, irrespective of the distance from a wall, in agreement with slender-body hydrodynamics theory. Moreover, the presence of small kinks does not affect the chain's axial diffusivity. Our system and measurements provide insights into fundamental axial diffusion processes of slender objects, which encompass a wide range of entities including biological filaments and linear polymer chains.
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