Synthesis of water-dispersible zinc oxide quantum dots with antibacterial activity and low cytotoxicity for cell labeling.

Typical photoluminescent semiconductor nanoparticles, called quantum dots (QDs), have potential applications in biological labeling. When used to label stem cells, QDs may impair the differentiation capacity of the stem cells. In this study, we synthesized zinc oxide (ZnO) QDs in methanol with an average size of ∼2 nm.

Transparent nanocomposites of high refractive index based on epoxy resin and TiO2 nanoparticle.

A stepwise sol-gel method for the synthesis of stable colloidal TiO2 using hydrolysis and condensation reactions of titanium tetraisopropoxide (TTP) was investigated. The surface modification was carried out using 3-glycidoxypropyltrimethoxysilane (GPTMS). The particle size range of the modified TiO2 observed by TEM was 3-8 nm.

Preparation and characterization of the transparent hybrids of silicone epoxy resin and titanium dioxide nanoparticles via sol-gel reactions.

In order to prepare transparent hybrid films of high refractive index, nanoparticles of TiO2 were prepared and dispersed in a silicone epoxy (SE) resin synthesized from diphenyl silane diol and [2-(3,4-epoxycyclohexyl)ethyl] trimethoxysilane by sol-gel reactions. It was found that amorphous TiO2 nanoparticles of about 5 nm modified with hexahydro-4-methyl phthalic anhydride [HMPA] were dispersed in the SE resin without agglomerations. The refractive index of the hybrids increased linearly with increasing the TiO2 contents.

Effects of colloidal nanosilica on the rheological properties of epoxy resins filled with organoclay.

The rheological properties of epoxy resins filled with organoclay and colloidal nanosilica were investigated by employing a parallel plate rheometer in flow mode at 25 degrees C. Shear thickening and shear thinning behaviors were observed in the epoxy resins filled with a mixture of organoclay and colloidal nanosilica. Minima were observed in the relaxation time of the systems consisting of epoxy resins filled with organoclay and colloidal silica as the content of colloidal nanosilica was increased.

A household survey on morbidity and treatment of acute respiratory infections in communities in Vietnam.

Objective: To ascertain the extent of under-utilization and insufficiency or inappropriateness in provision of health services as one of the possible causes of high mortality from pediatric pneumonia in pilot areas in Vietnam.

Method: The household survey on morbidity and treatment of acute respiratory infections, simple cough, and cold and pneumonia, was conducted in two communities with 10% sampling of the child population.

Results: Both under-treatment of "fast breathing", a proxy for pneumonia, and over-treatment of simple cough and cold with antimicrobials by health workers, mothers, and private practitioners were common.