Polyimide (PI)-based composites containing single-wall carbon nanohorn aggregate (NH) were fabricated using the spark plasma sintering (SPS) process. For comparison, composites with carbon nanotube (NT) and traditional graphite (Gr) were also fabricated. The NH was produced using CO 2 laser vaporization and a graphite target and the NT was produced by a chemical synthesis method. We evaluated the friction and wear properties of the PI-based composites with a reciprocating friction tester in air using an AISI 304 mating ball. NH drastically decreased the wear of PI-based composites; the specific wear rate of composite with NH of only 5 wt% was of the order of 10 )8 mm 3 /Nm, which was two orders of magnitude less than that of PI alone. The wear reduction ability of NT seemed to be slightly inferior to that of NH, although it was considerably better than that of Gr. NH and NT lowered the friction of composites. The friction coefficient of composite with 10 wt% NH was less than 0.25, although it was slightly higher than that of composite with 10 wt% Gr. There was no clear difference in the friction reduction effect of NH and NT. The further addition of Gr to composites with NH or NT rather deteriorated the antiwear property of composites, although the friction coefficient was slightly reduced. The transferred materials existed on the friction surface of the mating ball, sliding against composites with three types of carbon filler. These transferred materials seemed to correlate with the low friction and wear properties of composites.
We evaluated the immunogenicity and protective activity of plasmid DNA vaccines encoding the influenza virus NP gene (pNP) alone or in combination with the herpes simplex virus type 1 protein 22 gene (pVP22). Optimal immune responses were observed in BALB/c mice immunized with the combination of pVP22 plus pNP, as assessed by enzyme-linked immunosorbent assay (ELISA), enzyme-linked immunospot (ELISPOT) and intracellular cytokine staining (ICCS). These mice also showed maximal resistance following challenge with the A/PR/8/34 (H1N1) and A/Udron/72 (H3N2) strains of influenza virus. The susceptibility of immunized mice to virus infection was significantly increased following depletion of either CD4+ or CD8+ T cells. These results indicate that a plasmid DNA vaccine encoding pVP22 plus NP induces a high level of cross-protective immunity against influenza virus subtypes.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.