A Silver-Based Electrocontact Material Dispersion-Strengthened with Zinc,Tin, and Titanium Oxides

Technical Physics - A new silver-based electrocontact material dispersion-strengthened with nanopowders of zinc, tin, and titanium oxides has been obtained. The microstructure and elemental...     

Catalytic peoperties of palladium. Fixed on poly(m- and p-) hydroxyphenylbenzoxazole-terephthalamides

Conclusion Polymeric chelates of palladium with poly(m- and p-)hydroxyphenylbenzoxazoleterephthalamides as fibers exhibit catalytic activity in the hydrogenation of monoolefins and dienes.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1420–1421, June, 1982.     

Novel cationic amphiphilic derivatives from vernonia oil: synthesis and self-aggregation into bilayer vesicles, nanoparticles, and DNA complexants

Self-assembling nanostructures were prepared from novel cationic amphiphilic compounds synthesized from vernonia oil, a natural epoxydized triglyceride. The presence of a 12,13-epoxy group on the C18 unsaturated fatty acid, vernolic acid, which is the main constituent of vernonia oil, permitted the synthesis of novel amphiphilic derivatives with a hydrogen-bonding hydroxyl and a cationic headgroup moiety on adjacent carbon atoms. The amphiphiles were prepared in a two-stage synthesis that comprised opening of the epoxy groups with a haloacetic acid, followed by quaternization of the halo group with a tertiary amine containing a C12 aliphatic chain. Intact vernonia oil as the starting material gave a triple-headed cationic amphiphile, containing three vernolic acid derived moieties connected through a glycerol backbone. A single-headed amphiphile with two alkyl chains and a single quaternary ammonium headgroup was synthesized from the methyl ester of vernolic acid as the starting material. The triple-headed derivative could form nonencapsulating structures. Cholesterol was required in the formulation (1:1) to make spherical vesicles that could encapsulate a water-soluble marker. The single-headed derivative, however, formed spherical encapsulating vesicles without cholesterol. TEM, NMR, and FT-IR were used to characterize the vesicles, and molecular structure vs morphology relationships were postulated on the basis of these data. The triple-headed amphiphile also formed a DNA complex that was highly resistant to hydrolysis by DNase. This amphiphile-DNA complex was used as vector for gene transfer in cell culture demonstrating efficient DNA transfection.     

Synthese und Eigenschaften der chelatbildenden heterocyclischen Polyamide. Polyamidbenzimidazol

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