Mechanical force regulates a broad range of molecular interactions in biology. Three types of counterintuitive mechanical regulation of receptor-ligand dissociation have been described. Catch bonds are strengthened by constant forces, as opposed to slip bonds that are weakened by constant forces. The phenomenon that bonds become stronger with prior application of cyclic forces is termed cyclic ...

Theory is developed to address a significant problem of how two charged dielectric particles interact in the presence of a polarizable medium that is a dilute solution of a strong electrolyte. The electrostatic force is defined by characteristic parameters for the interacting particles (charge, radius, and dielectric constant) and for the medium (permittivity and Debye length), and is expressed...

The influence of the sample size (diameter while keeping the length constant) in equal channel angular pressing (ECAP) of pure aluminum is examined using finite element method (FEM) and experiment. Different sized aluminum rods were processed via ECAP and the effect of sample size on the strain homogeneity, process load, and the ratio of the friction to the total force were evaluated. The resul...

The force field used was MMF94s, without any solvent treatment. A constant dielectric of 1.0 was employed for the electrostatic treatment, whereas the charges were assigned by the force field (Fig. 1). Moreover, an extended non-bonded cut-off was set, for taking into account the best maximum distances over which hydrogen bonding, Van der Waals and electrostatic contributions to the molecular po...

A simple rigid three-site model for methanol compatible with the simple point charge ~SPC! water and the GROMOS96 force field is parametrized and tested. The influence of different force-field parameters, such as the methanol geometry and the charge distribution on several properties calculated by molecular dynamics is investigated. In particular an attempt was made to obtain good agreement wit...

Force probes allow reaction rates to be measured as a function of the restoring force in a molecule that has been stretched or compressed. Unlike strain energy, approaches based on restoring force allow quantitative molecular understanding of phenomena as diverse as translation of microscopic objects by reacting molecules, crack propagation and mechanosensing. Conceptually, localized reactions ...

Abstract To address coupling motion issues and realize large constant force range of microgrippers, we present a serial two-degree-of-freedom compliant microgripper (CCFMG) in this paper. output displacement compact structure, Scott–Russell amplification mechanisms, bridge-type lever mechanisms are combined to compensate stroke piezoelectric actuators. In addition, modules utilized achieve outp...

Molecular dynamics simulations of supercritical electrolyte solutions with three different ion–water models are performed to study the anion–cation potential of mean force of an infinitely dilute aqueous NaCl solution in the vicinity of the solvent’s critical point. The association constant for the ion pair Na/Cl and the constant of equilibrium between the solvent-separated and the contact ion ...

A method is proposed to measure the water permeability of membrane channels by means of molecular dynamics simulations. By applying a constant force to the bulk water molecules and a counter force on the complementary system, a hydrostatic pressure difference across the membrane can be established, producing a net directional water flow. The hydraulic or osmotic permeability can then be determi...