Dynamic force spectroscopy (DFS) makes it possible to investigate specific interactions between two molecules such as ligand-receptor pairs at the single-molecule level. In the DFS method based on the Bell-Evans model, the unbinding force applied to a molecular bond is increased at a constant rate, and the force required to rupture the molecular bond is measured. By analyzing the relationship b...

Type IV pili play an important role in bacterial adhesion, motility, and biofilm formation. Here we present high-resolution atomic force microscopy (AFM) images of type IV pili from Pseudomonas aeruginosa bacteria. An individual pilus ranges in length from 0.5 to 7 microm and has a diameter from 4 to 6 nm, although often, pili bundles in which the individual filaments differed in both length an...

Background: A traumatic diaphragm rupture presents a unique obstacle to a minimally invasive surgical approach; most repairs are performed during an emergency laparotomy. Diaphragm injuries are diagnosed in the acute phase of blunt-force trauma in only 10% of cases, and a high index of suspicion must be maintained to avoid strangulation of the abdominal organs that have herniated into the thora...

The prevalence of Achilles tendon (AT) injury is high in various sports, and AT rupture patients have been reported to have a 200-fold risk of sustaining a contralateral rupture. Tendon adaptation to different exercise modes is not fully understood. The present study investigated the structural properties of the AT in male elite athletes that subject their AT to different exercise modes as well...

A new cohesive zone model is developed in order to study the mechanisms of adhesive and cohesive failures of soft rubbery materials. The fracture energy is estimated here using a strategy similar to that of Lake and Thomas (LT) by considering the dissipation of stored elastic energy followed by the extension and relaxation of polymer chains. The current model, however, departs from that of LT i...

I n addition to labor force and capital, energy plays a significant role in the production of commodities and services. Energy is the driving force of production activities. Therefore, it is an essential ingredient of growth and development. Results obtained from this paper show that the growth of oil products consumption has a positive effect on economic development via two channels: Firstly,...

The objective of this study was to investigate the swelling characteristics of various swellable polymers in swelling layers that induce the rupturing of an outer polymer coating in pulsatile drug delivery systems (DDS). An apparatus was designed to measure simultaneously the swelling energy/force and water uptake of discs, made of polymers. The swelling energy of several excipients decreased i...

Kinetic partitioning is predicted to be a general mechanism for proteins to fold into their well defined native three-dimensional structure from unfolded states following multiple folding pathways. However, experimental evidence supporting this mechanism is still limited. By using single-molecule atomic force microscopy, here we report experimental evidence supporting the kinetic partitioning m...