Altered Antioxidant-Oxidant Status in the Aqueous Humor and Peripheral Blood of Patients with Retinitis Pigmentosa

Retinitis Pigmentosa is a common form of hereditary retinal degeneration constituting the largest Mendelian genetic cause of blindness in the developed world. It has been widely suggested that oxidative stress possibly contributes to its pathogenesis. We measured the levels of total antioxidant capacity, free nitrotyrosine, thiobarbituric acid reactive substances (TBARS) formation, extracellular superoxide dismutase (SOD3) activity, protein, metabolites of the nitric oxide/cyclic GMP pathway, heme oxygenase-I and inducible nitric oxide synthase expression in aqueous humor or/and peripheral blood from fifty-six patients with retinitis pigmentosa and sixty subjects without systemic or ocular oxidative stress-related disease. Multivariate analysis of covariance revealed that retinitis pigmentosa alters ocular antioxidant defence machinery and the redox status in blood. Patients with retinitis pigmentosa present low total antioxidant capacity including reduced SOD3 activity and protein concentration in aqueous humor. Patients also show reduced SOD3 activity, increased TBARS formation and upregulation of the nitric oxide/cyclic GMP pathway in peripheral blood. Together these findings confirmed the hypothesis that patients with retinitis pigmentosa present reduced ocular antioxidant status. Moreover, these patients show changes in some oxidative-nitrosative markers in the peripheral blood. Further studies are needed to clarify the relationship between these peripheral markers and retinitis pigmentosa

Study of the Nanomechanics of CNTs under Tension by Molecular Dynamics Simulation Using Different Potentials

At four different strain rates, the tensile stress strain relationship of single-walled 12-12 CNT with aspect ratio 9.1 obtained by Rebo potential (Brenner, 1990), Airebo potential (Stuart et al., 2000), and Tersoff potential (Tersoff, 1988) is compared with that of Belytschko et al. (2002) to validate the present model. Five different empirical potentials such as Rebo potential (Brenner, 1990), Rebo potential (Brenner et al., 2002), Inclusion LJ with Rebo potential (Brenner, 1990), Airebo potential (Stuart et al., 2000), and Tersoff potential (Tersoff, 1988) are used to simulate CNT subjected to axial tension differing its geometry at high strain rate. In Rebo potential (Mashreghi and Moshksar, 2010) only bond-order term is used and in Rebo potential (Brenner et al., 2002) torsional term is included with the bond-order term. At high strain rate the obtained stress strain relationships of CNTs subjected to axial tension differing its geometries using five different potentials are compared with the published results and from the comparison of the results, the drawback of the published results and limitations of different potentials are evaluated and the appropriate potential is selected which is the best among all other potentials to study the elastic, elastic-plastic properties of different types of CNTs. The present study will help a new direction to get reliable elastic, elastic-plastic properties of CNTs at different strain rates. Effects of long range Van der Waals interaction and torsion affect the elastic, elastic-plastic properties of CNTs and why these two effects are really needed to consider in bond-order Rebo potential (Brenner, 1990) to get reliable elastic, elastic-plastic properties of CNTs is also discussed. Effects of length-to-diameter ratio, layering of CNTs, and different empirical potentials on the elastic, elastic-plastic properties of CNTs are discussed in graphical and tabular forms with published results as a comparative manner to understand the nanomechanics of CNTs under tension using molecular dynamics simulation.</jats:p

A numerical solution of a one end fixed glass/epoxy plate having a circular cutout subjected to a uniform shear using displacement potential approach

The finite-difference technique based on the displacement potential approach of orthotropic composite materials is extended to solve elastic plane stress problems of orthotropic composite materials with geometric perturbations, such as holes, arbitrary defects, notches, etc. In this analysis, one fixed elastic glass/epoxy plate having an internal hole is considered and a uniform shear load is applied to the opposite end of the supporting edge. Critical sections of the plate are identified with the detailed discussions of the elastic field of the plate. Effects of sizes of the holes of the plate on the elastic field are also discussed with the help of graphical solutions. The reliability of the extended finite-difference technique based on the displacement potential approach of orthotropic composite materials is shown by the comparison of solutions between the FDM and FEM

iFASP: Combining Isobaric Mass Tagging with Filter-Aided Sample Preparation

Careful, clean and controlled preparation of samples for mass spectrometry proteomics is crucial to obtain reproducible and reliable data. This is especially important when carrying out quantitative proteomics by chemical isobaric labeling (aka tandem mass tagging), since the differentially labeled samples are combined quite late during the sample processing. Addressing this need for robust and reliable sample processing for quantitative proteomics, we describe here iFASP, a simple protocol for combining isobaric mass tagging with the recently introduced filter-aided sample preparation (FASP) method. iFASP provides a quick, simple and effective method for obtaining clean samples, ensuring efficient digestion and providing excellent labeling yields for quantitative proteomics experiments. We have carried out our iFASP protocol using several highly complex <i>Xenopus laevis</i> egg and embryo lysates and compared the labeling yields and number of high-confidence peptide identifications to a standard in-solution digestion and labeling protocol. Although the labeling efficiency with both techniques is in the 99+% range, the number of peptides identified with a 1% false discovery rate and the corresponding number of quantified peptide spectral matches are as much as doubled with iFASP compared to the corresponding non-FASP-based method