Application of pulling force, under force-clamp conditions, to kinetochore-microtubule attachments in-vitro revealed a catch-bond-like behavior. In an earlier paper (Sharma et al. Phys. Biol. (2014) the physical origin of this apparently counter-intuitive phenomenon was traced to the nature of the force-dependence of the (de-)polymerization kinetics of the microtubules. In this brief communicat...

The mechanism of action of Sterilox, a non-toxic liquid biocide produced by electrolysis of a dilute saline solution, upon planktonic cells of Escherichia coli JM109 was investigated using protein and nucleic acid analysis. The results revealed total destruction of chromosomal and plasmid DNA, RNA and proteins of E. coli within 5 min of exposure. Our earlier investigation conducted using atomic...

We have imaged adsorbed fluid lipid bilayers by atomic force microscopy. The patches were formed by rupture of phospholipid vesicles onto magnesium fluoride. We show that the membrane patches are fluid but can be stably imaged at scan rates higher than 6 p d s . At lower scan rates the tip penetrates through the layer. The penetrating tip does not destroy the fluid patches, and the previous ima...

Viruses are biological agents with great potential in the field of nanotechnology. Nowadays, their amazing properties are starting to be unveiled using physical techniques like the atomic force microscope. In this study, we have used a Virtual AFM, i.e., a simulator that mimics a typical AFM nanoindentation experiment, to study the mechanical properties of viral shells. In particular, with our ...

Cell migration in morphogenesis and cancer metastasis typically involves interplay between different cell types. We construct and study a minimal, one-dimensional model composed of two different motile cells with each cell represented as an active elastic dimer. The interaction between the two cells via cadherins is modeled as a spring that can rupture beyond a threshold force as it undergoes d...

Triceps tendon injuries are relatively rare and represent less than 1% of all tendon injuries [1-3]. Ruptures typically occur following an eccentric force applied against an actively contracting triceps, but may occur following direct trauma [4-8].Tendon ruptures can occur due to intrinsic or extrinsic factors, and risk rupturing with a rapidly applied force [9-10]. The most common mechanism ty...

We develop and investigate an integral equation connecting the first passage time distribution of a stochastic process in the presence of an absorbing boundary condition and the corresponding Green's function in the absence of the absorbing boundary. Analytical solutions to the integral equations are obtained for three diffusion processes in time-independent potentials which have been previousl...

A laser trap was used to compare the load-dependent binding kinetics between truncated P- and L-selectin to their natural ligand, P-selectin glycoprotein ligand-1 (PSGL-1) over the predicted physiological range of loading rates. Human PSGL-1 was covalently coupled to polystyrene beads. Chimeric selectins were adsorbed to nitrocellulose-coated glass beads on a coverslip. A PSGL-1 bead was held i...

[1] Acoustic emissions and tremor‐like signals are widely recorded in laboratory experiments. We are able to isolate the physical origins of these signals using high resolution nanoseismic analysis. The use of a picometer‐sensitive, wide‐band sensor array permits us to determine force‐time functions and focal mechanisms for discrete events found amid the “noise” of friction, similar to how low ...

The rupture of a liquid film on a solid surface and of a free liquid film have been studied using hydrodynamic stability theory. The films are not thicker than several hundred hgstrom. A sinall perturbation applied to the free interface generates motions in the film, and the assumption is made that the NavierStokes equations can be used to describe them. The difference in forces acting upon an ...