The force required to rupture the streptavidin-biotin complex was calculated here by computer simulations. The computed force agrees well with that obtained by recent single molecule atomic force microscope experiments. These simulations suggest a detailed multiple-pathway rupture mechanism involving five major unbinding steps. Binding forces and specificity are attributed to a hydrogen bond ne...

The forced rupture of single chemical bonds in biomolecular compounds (e.g. ligand-receptor systems) as observed in dynamic force spectroscopy experiments is addressed. Under the assumption that the probability of bond rupture depends only on the instantaneously acting force, a data collapse onto a single master curve is predicted. For rupture data obtained experimentally by dynamic AFM force s...

The mechanical properties of potato (Solanum tuberosum L.) in various treatments including: three different varieties (Agria, Satina and Caesar), ten levels of storage time (22 weeks), and three levels of loading direction were presented in this study by conducting 270 uniaxial compression tests. The tests were performed on potato flesh in real conditions of storage. The measurements were done ...

dried figs collected from various exporting companies (2,461 samples) and local stores (219 samples) were analyzed using reverse-phase high-performance liquid chromatography (rp-hplc) to determine and compare the incidence of aflatoxins, the effectiveness of the regulation limits and monitoring system to select non-compliant samples and the mean daily aflatoxin exposures. the incidence rates of...

In this research, two new methods that improve the drawing depth of deep-drawing processes have been introduced. In the first technique, by creating ridges on the punch surface, the stress concentration is decreased on the blank near the punch edge, in turn increasing the drawing depth. The second method is based on the principle of reducing resistant force in the flange area between the die, t...