DNA experiences torsional stress resulting from the activities of motor enzymes and bound proteins. The mechanisms by which this torsional stress is dissipated to maintain DNA structural integrity are not fully known. Here, we show that a Holliday junction can limit torsion by coupling rotation to translocation and torque to force. The torque required to mechanically migrate through individual ...

We study two systems of nonlinearly coupled ordinary di erential equations that govern the vertical and torsional motions of a cross section of a suspension bridge. We observe numerically that the structure of the set of periodic solutions changes considerably when we smooth the nonlinear terms. The smoothed nonlinearities describe the force that we wish to model more realistically and the resu...

Resonance Raman spectra of individual strained ultralong single-wall carbon nanotubes (SWNTs) are studied. Torsional and uniaxial strains are introduced by atomic force microscopy manipulation. Torsional strain strongly affects the Raman spectra, inducing a large downshift in the E2 symmetry mode in the G+ band, but a slight upshift for the rest of the G modes and also an upshift in the radial ...

INTRODUCTION The purpose of this study was to compare the torsion and bending properties of OneShape (OS; Micro Mega, Besançon, France) and WaveOne (WO; Dentsply Maillefer, Ballaigues, Switzerland) single-file systems. METHODS The torsional strength of OS size #25, 0.06 taper and WO primary size #25, 0.08 taper was measured by using a torsiometer after fixing the apical 5 mm of the instrument...

The Casimir force between uncharged metallic surfaces originates from quantum-mechanical zero-point fluctuations of the electromagnetic field. We demonstrate that this quantum electrodynamical effect has a profound influence on the oscillatory behavior of microstructures when surfaces are in close proximity (< or =100 nm). Frequency shifts, hysteretic behavior, and bistability caused by the Cas...

The MD simulations have been performed using the OPLS force-field [1]. The toluene and phosphine molecules have been treated as fully rigid bodies, whereas the borane molecule has been also parametrized for pyramidalization and aryl torsions. The functional form of the force-field consists of harmonic terms for bond stretching and angle bending, Fourier series for torsional energetics, and Coul...

Abstract The torsional vibration of marine propulsion shafting has been studied for more than a century. With abundant research achievements and experiences, a systematic approach of vibration calculation has been put forward for ship industrial applications. However, literature review indicates that when processing the gear transmission in the shaft line, the meshing motion has been treated as...

We are developing a new method using ultrasonic longitudinal and torsional vibration of a hollow-type stepped horn for hole machining. We foresee that the equipment can be simplified and miniaturized. In this paper, ultrasonic vibration sources of a hollow-type stepped horn without a diagonal slits vibration converter and with a diagonal slits vibration converter are used. The longitudinal and ...

Explicit-solvent molecular dynamics simulations (50 ns, 300 K) of the eight reducing glucose disaccharides (kojibiose, sophorose, nigerose, laminarabiose, maltose, cellobiose, isomaltose, and gentiobiose) have been carried out using the GROMOS 45A4 force field (including a recently reoptimized carbohydrate parameter set), to investigate and compare their conformational preferences, intramolecul...