The rupture in metals can occur by cleavage, where all process is controlled stresses, or ductile fracture, which takes into account the damage caused nucleation and growth of voids.The then dependent on stresses strains. Linear Elastic Fracture Mechanics, widely used engineering practice, based assumption that first prevails, occurs only under certain conditions. Consideration second fracture ...

The identification of intermediates and by-products issuing from the oxidative cleavage cycloolefins allows proposing a reaction mechanism.

We have characterized a novel Zn2+-catalyzed cleavage site between nucleotides C3 and U4 in the catalytic core of the hammerhead ribozyme. In contrast to previously described divalent metal-ion-dependent cleavage of RNA, U4 cleavage is only observed in the presence of Zn2+. This new cleavage site has an unusual pH dependence, in that U4 cleavage products are only observed above pH 7.9 and reach...

background: mammalian oocytes are exposed to a mixture of many different growth factors and cytokines which provides an optimized microenvironment for oocyte maturation. in the lack of this natural microenvironment in vitro the quality of oocyte and embryos appears to be suboptimal. objective: this study was undertaken to investigate the effects of egf and lif on in vitro maturation fertilizati...

Background Timing of the first zygotic cleavage is an accurate predictor of embryo quality. Embryos that cleaved early (EC) have been shown to exhibit higher developmental viability compared to those that cleaved at a later period (LC). However, the viability of EC embryos in comparison to LC embryos after vitrification is unknown. The present study aims to investigate the post-vitrification de...

A nonenzymatic digestion technique allows proteins to be well suited for collision-induced dissociation tandem mass spectrometry. This method utilizes microwaves and Dithiothreitol (DTT) to selectively cleave at aspartic acid (D) and disulfide bonds. This microwave digestion technique is reproducible and produces peptides with a shortened sequence length. Insulin I is used in this study to opti...

Infection of cells by many picornaviruses results in the rapid inhibition of cellular protein synthesis due to cleavage of the translation initiation factor eIF4G. The poliovirus (PV) 2A and foot-and-mouth disease virus (FMDV) L proteases are each sufficient to mediate this cleavage, but the cleavage mechanism may be indirect, involving an unidentified cellular protease(s). eIF4G is also target...