Recent studies have advanced the notion that the axonal organization of neurofilaments (NFs) is based on mutual steric repulsion between the unstructured "sidearm" domains of adjacent NFs. Here, we present experimental evidence that these repulsive forces are modulated by the degree of sidearm phosphorylation. When NFs are sedimented into a gelatinous pellet, pellet volume falls with increasing...

We have developed atomic-scale material models capable of melting, crystallization and amorphization. These models feature molecular dynamics governed by Langevin equations of motion in which particle interact through attractive covalent forces and short-range repulsion forces. Also, we present an interactive virtual visualization tool for the simulation of atomic scale material behavior. An ap...

Polymer coatings are frequently used to provide repulsive forces between surfaces in solution. After 25 years of design and study, a quantitative model to explain and predict repulsion under strong compression is still lacking. Here, we combine experiments, simulations, and theory to study polymer coatings under high loads and demonstrate a validated model for the repulsive forces, proposing th...

We have experimentally investigated the interactions between floating magnetic spheres which are submitted to a vertical magnetic field, ensuring a tunable repulsion, while capillary forces induce attraction. We emphasize the complex arrangements of floating bodies. The equilibrium distance between particles exhibits hysteresis when the applied magnetic field is modified. Irreversible processes...

We have studied molecular interactions in solutions of the protein apoferritin by static and dynamic light scattering. When plotted against the electrolyte concentration, the second osmotic virial coefficient exhibits a minimum. The ascending branch of this dependence is a manifestation of a surprisingly strong repulsion between the molecules at electrolyte concentrations about and above 0.2M, ...

We study the electrostatic interaction between two ionic surfactant layers by performing molecular dynamic simulations of salt-free thin water films coated by surfactants (Newton black films). We find a strong exponentially decaying short-range repulsion not explained by classical Poisson-Boltzmann theory. This electrostatic force is shown to be mainly due to the anomalous dielectric response o...

Due to the breakdown of Derjaguin approximation at the nanoscale level apart from the neglect of the atomic discrete structure, the underestimated number density of atoms, and surface effects, the continuum Hamaker model does not hold to describe interactions between a spherical nanoparticle and a flat surface. In this work, the interaction forces including van der Waals (vdW) attraction, Born ...

Understanding adhesion of micro-particles particularly microcapsules containing a functional active on fabric surface is crucial to effective delivery of the active to the latter. Fabric surface is very rough, and direct measurement of the adhesion of single micro-particles on surfaces with roughnesses greater than the particle diameter can be difficult. In this work cotton films were successfu...

The potential fields method for autonomous robot navigation consists essentially in the assignment of an attractive potential to the goal point and a repulsive potential to each of the obstacles in the environment. Several implementations of potential fields for autonomous robot navigation have been reported. The most simple implementation considers a known environment where fixed potentials ca...