The Role of hOGG1 C1245G Polymorphism in the Susceptibility to Lupus Nephritis and Modulation of the Plasma 8-OHdG in Patients with Systemic Lupus Erythematosus

We investigated whether the C1245G polymorphism of human 8-oxoguanine glycosylase 1 (hOGG1) gene confers the susceptibility to systemic lupus erythematosus (SLE) occurrence of lupus nephritis and affects the plasma level of 8-hydroxy-2''-deoxyguanosine (8-OHdG) in patients with SLE. A total of 45 healthy controls and 85 SLE patients were recruited. The C1245G polymorphism of the hOGG1 gene was determined by direct sequencing. The frequency of occurrence of the hOGG1 1245 GG genotype in SLE patients was 31.8% (27/85), which is lower than that of healthy controls of 53.3% (24/45). Thirty-three (33/85, 38.8%) SLE patients developed lupus nephritis. Significantly, SLE patients harboring the hOGG1 1245 GG genotype had a higher incidence to develop lupus nephritis than did those harboring the hOGG1 1245 CC or CG genotype (15/27, 55.6% vs.18/58, 31.0%, p = 0.031). Divided into subgroups, SLE patients harboring the hOGG1 1245 GG genotype had the highest plasma levels of 8-OHdG among patients with all genotypes, with regard to the coexistence of lupus nephritis (p = 0.020, ANOVA), including those with nephritis harboring the hOGG1 1245 CC or CG genotypes (p = 0.037), those without nephritis harboring the hOGG1 1245 GG genotype (p = 0.050), and those without nephritis harboring the hOGG1 1245 CC or CG genotype (p = 0.054). We conclude that the C1245G polymorphism of hOGG1 may be one of the factors that confer the susceptibility to lupus nephritis and modulate the plasma level of 8-OHdG in patients with SLE.     

Distinct dispersion stability of various TiO2 nanopowders using ammonium polyacrylate as dispersant

The dispersion stabilities of three titania (TiO₂) nanopowders with different particle sizes and surface chemistries in aqueous suspensions containing a common water-based dispersant, ammonium polyacrylate (PAA-NH₄), have been investigated and compared. According to adsorption isotherm and Fourier transform infrared spectroscopy analyses, the adsorption conformations of PAA-NH₄ are distinct for the different TiO₂ nanopowders. In addition, PAA-NH₄ exhibited the greatest adsorption affinity to the larger, hydrophilic TiO₂ nanopowder and the least affinity to smaller, hydrophobic nanopowder. From sedimentation and rheological results, the dispersion stability of the larger, hydrophilic TiO₂ nanopowder was demonstrated to be the greatest. Based on thermodynamic and kinetic calculations for the stabilization energies, the larger, hydrophilic TiO₂ nanopowder was also shown to be the best-stabilized powder, although it settles faster than the smaller, hydrophilic TiO₂ nanopowder; this is due to the greater affection of sedimentation flux on the larger nanopowder. In contrast, the hydrophobic TiO₂ nanopowder formed a gel-like structure in the aqueous suspension when the solid content was greater than 10 wt%, which is attributed to polymer bridging between PAA-NH₄-adsorbed TiO₂ nanoparticles.     

Mixed Broadcast Techniques of Leisure Information in Vehicular Ad-Hoc Networks

Telecommunication Systems - Vehicle-to-vehicle communication and probabilistic broadcast are important means for information dissemination in vehicular ad-hoc networks (VANETs). In contrast to...     

Effect of long-chain branching molar fraction on scratch behavior of polypropylene

Polymers containing a certain amount of long-chain-branching (LCB) structure are expected to possess improved mechanical properties over those of the linear structure counterpart. However, fundamental knowledge on the structure–property relationship in LCB containing polypropylene (PP) is still illusive. In the present study, a set of model PP systems containing an increasing molar fraction of LCB (5–19 mol%) were prepared by reactive extrusion to determine how LCB content may influence the scratch behavior of PP. It is shown that with only 5 mol% of LCB content in PP can improve resistance against scratch-induced fish-scale formation by over 25%. The improvement of scratch resistance is attributed to the increases in entanglement density in LCB-containing PPs, which is evidenced by their creep-recovery behavior. The present study demonstrates that the incorporation of LCB in PP leads to higher viscoelastic recovery and increased tensile strength, which account for the observed improvement in scratch performance. The usefulness of LCB in polymers for improving scratch performance is discussed.