Biomedical subjects

Kazutaka Nagao

Publications and source records attributed to Kazutaka Nagao.

3 recordsLinked to original sources

PubMed2006

Stability of cellular foam generated from amphoteric surfactant aqueous solution.

Experiments were carried out to investigate the stability of cellular foam generated from an amphoteric surfactant aqueous solution in a standard bubble column. A typical growth and collapse process were found, and the cellular foam became stable with increasing pH of the solution under both acidic and basic conditions. The critical film thickness calculated from the thinning equation, the well-known Reynolds equation, was between 100 to 400 nm. Of particular note is that the cellular foam was not observed at pH=7 of the liquid.

Hydrogen-Ion Concentration↗

PubMed2006

Production of sepedonin by Sepedonium chrysospermum NT-1 in submerged culture.

Strains of Sepedonium chrysospermum and the anamorph strain of Hypomyces chrysospermus (congruent with Apiocrea chrysosperma) were isolated and purified from parasitic filamentous fungi on the fruiting bodies of Boletaceae, such as the Gyroponus and Suillus genera in Japan, and identified from formations of conidia and chlamydospores. It is known that these strains produce sepedonin. S. chrysospermum NT-1 strain was selected from these strains and isolated. As the optimum medium (CY-1 medium), 0.1% yeast extract was added to the fruiting-body-forming medium (C medium) of Schizophyllum commune. After 8 days of growth on CY-1 medium, the yield of sepedonin was about 34 mg per 2 g of glucose added. This sepedonin seemed to inhibit the growth of various gram-positive and gram-negative bacteria, yeasts and molds.

Anti-Infective Agents↗

PubMed2003

Enhanced Friedel structure and proton pairing in dense solid hydrogen.

The mechanism of proton pairing in dense solid hydrogen, and its progression with density, are both studied using effective potentials between protons which include electronic response up to quadratic terms. For high pressures nonlinear effects originating with different pairs are crucial in establishing the net attraction within a given pair, and in this picture Friedel oscillations are considerably enhanced by quadratic response, subsequently playing a very important role in the overall pairing. Calculated vibron frequencies also show substantial agreement with experiment, reflecting at the same time significant changes in the physical character of the pairing itself.

Journal Article↗