Torsional restraints on DNA change in time and space during the life of the cell and are an integral part of processes such as gene expression, DNA repair and packaging. The mechanical behavior of DNA under torsional stress has been studied on a mesoscopic scale, but little is known concerning its response at the level of individual base pairs and the effects of base pair composition. To answer...

It is well known that transcription can induce torsional stress in DNA, affecting the activity of nearby genes or even inducing structural transitions in the DNA duplex. It has long been assumed that the generation of significant torsional stress requires the DNA to be anchored, forming a limited topological domain, because otherwise it would spin almost freely about its axis. Previous estimate...

This article demonstrates a new approach for nonlinear finite element analysis. The methodology is very suitable and gives very accurate results in linear as well as in nonlinear range of the material behavior. Proposed methodology can be regarded as stress based finite element analysis as it is required to define the stress distribution within the structural body with structural idealization a...

DNA torsional stress is generated by virtually all biomolecular processes involving the double helix, in particular transcription where a significant level of stress propagates over several kilobases. If another promoter is located in this range, this stress may strongly modify its opening properties, and hence facilitate or hinder its transcription. This mechanism implies that transcribed gene...

The sequence dependence of the conformational distribution of DNA under various levels of torsional stress is an important unsolved problem. Combining theory and coarse-grained simulations shows that the DNA sequence and a structural correlation due to topology constraints of a circle are the main factors that dictate the 3D structure of a 336 bp DNA minicircle under torsional stress. We found ...

the finite element method is employed for the flexural-torsional linear buckling analysis of beams of arbitrarily shaped composite cross-section taking into account generalized warping (shear lag effects due to both flexure and torsion). the contacting materials, that constitute the composite cross section, may include a finite number of holes. a compressive axial load is applied to the beam. the...

The study of surface waves in a layered media has their viable application in geophysical prospecting. This paper presents an analytical study on the dispersion of torsional surface wave in a pre-stressed heterogeneous layer sandwiched between a pre-stressed anisotropic porous semi-infinite medium and gravitating anisotropic porous half-space. The non-homogeneity within the intermediate layer a...

The finite element method is employed for the flexural-torsional linear buckling analysis of beams of arbitrarily shaped composite cross-section taking into account generalized warping (shear lag effects due to both flexure and torsion). The contacting materials, that constitute the composite cross section, may include a finite number of holes. A compressive axial load is applied to the beam. The...

INTRODUCTION: Intervertebral disc experiences large complex deformations including compression, rotation, and bending under daily activity. For example, twisting while carrying a weight, loads the disc under axial compression and axial rotation. Previous work showed that the rate of degeneration and disc injury is higher for in workers that experience repetitive twisting and lifting [1]. Disc d...

fabrication, characterization and application of micro-/nano-rods/wires are among the hottest topics in materials science and applied physics. micro-/nano-rod-based structures and devices are developed for a wide-ranging use in various fields of micro-/nanoscience (e.g. biology, electronics, medicine, optics, optoelectronics, photonics and sensors). it is well known that the structure and prope...