Three-dimensional heterostructure of metallic nanoparticles and carbon nanotubes as potential nanofiller

The effect of the dimensionality of metallic nanoparticle-and carbon nanotube-based fillers on the mechanical properties of an acrylonitrile butadiene styrene (ABS) polymer matrix was examined. ABS composite films, reinforced with low dimensional metallic nanoparticles (MNPs, 0-D) and carbon nanotubes (CNTs, 1-D) as nanofillers, were fabricated by a combination of wet phase inversion and hot pressing. The tensile strength and elongation of the ABS composite were increased by 39% and 6%, respectively, by adding a mixture of MNPs and CNTs with a total concentration of 2 wt%. However, the tensile strength and elongation of the ABS composite were found to be significantly increased by 62% and 55%, respectively, upon addition of 3-D heterostructures with a total concentration of 2 wt%. The 3-D heterostructures were composed of multiple CNTs grown radially on the surface of MNP cores, resembling a sea urchin. The mechanical properties of the ABS/3-D heterostructured nanofiller composite films were much improved compared to those of an ABS/mixture of 0-D and 1-D nanofillers composite films at various filler concentrations. This suggests that the 3-D heterostructure of the MNPs and CNTs plays a key role as a strong reinforcing agent in supporting the polymer matrix and simultaneously serves as a discrete force-transfer medium to transfer the loaded tension throughout the polymer matrix

Peroxynitrite inhibition of Coxsackievirus infection by prevention of viral RNA entry

Although peroxynitrite is harmful to the host, the beneficial effects of peroxynitrite are less well understood. We explored the role of peroxynitrite in the host immune response to Coxsackievirus infection. Peroxynitrite inhibits viral replication in vitro, in part by inhibiting viral RNA entry into the host cell. Nitrotyrosine, a marker for peroxynitrite production, is colocalized with viral antigens in the hearts of infected mice but not control mice. Nitrotyrosine coprecipitates with the viral polypeptide VP1 as well. Guanidinoethyl disulfide, a scavenger of peroxynitrite, blocks peroxynitrite inhibition of viral replication in vitro and permits an increase in viral replication in vivo. These data suggest that peroxynitrite is an endogenous effector of the immune response to viruses