BACKGROUND Adhesive systems have enabled clinicians to preserve more tooth structure by changing cavity designs. However, because of the polymerization shrinkage adhesive systems are not capable of totally prohibiting the gap formation between the cavity and restorative material of composite resin leading to colonization of oral microorganisms from saliva. One possible solution for this serious...

J. L. Gao, Y. Zhi, X. F. Ren, Y. H. Liu, College of Material Science and Engineering, Shenyang Ligong University, Shenyang, Liaoning, China. Barium titanate (B aTiO3) nanoparticles were successfully synthesized by using a surfactant-assisted method. The various processing parameters, namely, th e species of surfactant, reaction temperature and micro-emusion concentration had been varied, and th...

Mixed association of calix[4]resorcinarene with ethyl sulfonate groups on the lower rim and dimethylaminomethyl groups on the upper rim (CR) and cationic surfactant 4-aza-1-hexadecyl-azoniabicyclo[2.2.2]octane bromide (DABCO-16) is studied by methods of tensiometry, conductometry, potentiometry and NMR spectroscopy at fixed CR concentration and varied surfactant concentration. Beyond ca. 0.4 mM...

Some N-alkyl pia-hydroxy styryl pyridinium halides, the alkyl moieties being methyl, hexyl and decyl, have been synthesised and the acid dissociation constants of these compounds in aqueous and surfactant solutions have been determined using spectrophotometric method . The alkyl chain does not have any substantial effect on the pKa values in aqueous and cationic surfactant (cetyl trimethylammon...

The effects of surface modifications of multi-walled carbon nanotubes (MWCNTs) on their dispersibility in different solvents and poly (ether ether ketone) (PEEK) have been studied. MWCNTs were treated by mixed acids to obtain acid-functionalized MWCNTs. The acid-functionalized MWCNTs were modified with six different chemical agents separately, 1,6-diaminohexane, hexadecyl trimethyl ammonium bro...

A simple, sensitive and reliable method for the separation, preconcentration and determination of ultra trace amounts of chromium species has been developed. Chromium(VI) in aqueous sample was reacted with 9-phenyl-2,3,7-trihydroxy-6-fluorone to produce a chelate at pH of 5.0 and extracted onto the magnetic nanoparticles coated with the ionic liquid 1-hexadecyl-3methylimidazolium bromide. The t...

Highly ordered Fe-MCM-41 molecular sieve was successfully synthesized by using n-hexadecyl-trimethyl ammonium bromide (CTAB) as the template and the iron ore tailings (IOTs) as the silicon and iron source. X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), diffuse reflectance UV-visible spectroscopy, (29)Si magic-angle spinning (MAS) nuclear magnetic resonance (N...

The metabolic fate of [1-14-C]hexadecylsulphate and hexadecyl[35-S]sulphate, administered intravenously as the sodium and trimethylammonium salt to dogs and orally as the erythromycin salt to dogs, rats and humans, was studied. Studies with rats indicated that the compounds were well absorbed and rapidly excreted in the urine. However, after oral administration of the 14-C-and 35-S-labelled hex...

Several phospholipase A2 (PLA2) activities have been identified in rat lung homogenate and shown to be important in metabolism of lung phospholipids. One PLA2 activity is Ca(2+)-independent, active in vitro at pH 4, and inhibited by a substrate analogue, 1-hexadecyl-3-trifluoroethylglycero-sn-2-phosphomethanol (MJ33). Purification of this rat lung PLA2 by approx. 550-fold was carried out by seq...

Surface strain tuning in a coupled heterostructure efficiently engineers the catalytic performance of heterogeneous catalysts by altering electronic structures and boosting electron transport. Generally, Bi-based are more favorable than ZnO for CO2 electroreduction to formate, but Bi is much costly Zn. Herein, new Bi2O2CO3/ZnO heterojunction catalyst with porous nanoplate morphology synthesized...