A theoretical model of a DNA oligonucleotide duplex featuring A-tracts phased by a full helix turn is developed based on molecular dynamics computer simulation. The extent to which this model agrees with relevant experimental data on axis bending and the relationship of A-tracts to bending and other aspects of helix morphology is investigated. Specifically, a series of nanosecond-level molecula...

This article covers the general behaviour of a straight uniform pipe, with built-in open ends, subject to internal pressure and in plane bending or curvature. It is intended as a summary of the basic equations driving the unintuitive phenomena of bending and instability of pipes under internal pressure. The analysis covers in addition the investigation of opposite pressure stabilisation effects...

STUDY DESIGN A retrospective series of 35 idiopathic scoliosis patients underwent spinal fusion with a segmental thoracic pedicle screw system. OBJECTIVE To evaluate the amount of scoliosis correction with segmental pedicle screw constructs, and assess whether the fulcrum bending radiograph can predict surgical correction. SUMMARY OF BACKGROUND DATA The fulcrum bending radiograph is highly ...

A simulation of the deflection of a single wall nanotube under the manipulation of an atomic force microscope tip revealed the key feature characterizing the deformation at relatively small bending angles to be a reversible transition from sp(2) to sp(3) bonding configurations in the bending region, leading to a 2 orders of magnitude reduction in conductance consistent with our most recent expe...

Hydrostatically pressurized circular rings confined to two dimensions (or cylinders constrained to have only z -independent deformations) undergo Euler-type buckling when the outside pressure exceeds a critical value. We perform a stability analysis of rings with arclength-dependent bending moduli and determine how weakened bending modulus segments affect the buckling critical pressure. Rings w...

Simple, accurate buckling interaction formulae are presented for long orthotropic plates with either simply supported or clamped longitudinal edges and under combined loading that are suitable for design studies. The loads include 1) combined uniaxial compression (or tension) and shear, 2) combined pure inplane bending and 3) shear and combined uniaxial compression (or tension) and pure inplane...

Motivated by recent experiments on bilayer polyhedra composed of amphiphilic molecules, we study the elastic bending energies of bilayer vesicles forming polyhedral shapes. Allowing for segregation of excess amphiphiles along the ridges of polyhedra, we find that bilayer polyhedra can indeed have lower bending energies than spherical bilayer vesicles. However, our analysis also implies that, co...

Heart attack and stroke are often caused by atherosclerotic plaque rupture, which happens without warning most of the time. Magnetic resonance imaging (MRI)-based atherosclerotic plaque models with fluid-structure interactions (FSIs) have been introduced to perform flow and stress/strain analysis and identify possible mechanical and morphological indices for accurate plaque vulnerability assess...

The author's recent investigations on plate theories form the basis to review development of plate theories. In spite of several review articles on plate theories reported in the literature, the present work is essentially due to Jemielita's inspiring article (1993). It is shown that methods of analysis based on vertical displacement as domain variable deal with solution of associated torsion p...

An inverse analyses procedure for determining the mechanical material properties of strain hardening cement-based materials is presented. It allows to determine the uniaxial stressstrain curve up to the material’s localization point on the basis of the results of four-point bending tests. In these tests, the beam curvature is measured and serves as input value for the inverse analysis. An evolu...