Improvement of isoamyl acetate productivity in sake yeast by isolating mutants resistant to econazole

Sake yeast strains were improved so as to produce larger amounts of isoamyl acetate than the parental strain by isolating econazole-resistant mutants. Econazole, an imidazole antimycotic, directly interacts with unsaturated fatty acids in the yeast cell membrane, where it also inhibits the synthesis of ergosterol and decreases the ratio of unsaturated to saturated fatty acids. In contrast, alcohol acetyltransferase (AATase), which catalyzes the synthesis of isoamyl acetate, is inhibited by unsaturated fatty acids. Fifty econazole-resistant mutants were isolated from a sake yeast, Kyokai no. 701, several of which produced approximately 1.4 to 2.4 times more isoamyl acetate and an almost equal amount of isoamyl alcohol compared with the parental strain. The AATase activities of the mutants in koji extract were 1.2 to 1.4 times higher, and the unsaturated to saturated fatty acid ratios were lower, than in the parental strain.     

Oxygen Configuration in the Superconductor (Hg0.7Mo0.3)Sr2(Ca1?xRx)Cu2Oz (R = Nd and Pr)

Two series of Hg-based oxides (Hg_0.7Mo_0.3)Sr₂(Ca_1–x R _x )Cu₂O _z (R = Nd and Pr, 0.2 x 0.7) have been synthesized. Electrical-resistivity measurements show that these compounds are superconductors with maximum onset T _c of 107 and 102 K for Nd- and Pr-containing samples, respectively. The neutron powder diffraction experiments on both as-prepared and O₂-annealed samples of R = Nd revealed that the O(3) site at the HgO sheets are fully occupied and shifted towards the Hg/Mo site to form Mo–O bonds.     

Physics-driven Multi Dimensional Keyframe Animation for Artist-directable Interactive Character

Various forms of art and entertainment involve many different characters, and advances in human interfaces have necessitated physical interactions in order to develop an improved sense of reality. In this paper we propose a method for generating the motions of characters using multidimensional keyframe animation in parallel with real-time physical simulation. The method generates characters capable of physical interaction, and also allows animators to use traditional methods for designing character motion. We have implemented the system and confirmed its effectiveness experimentally.     

Reactivity of cyclosiloxane with 3,3,4,4,5,5,6,6,6‐nonafluorohexyl group and its application to fluorosilicone synthesis

The reactivity of cyclosiloxane with 3,3,4,4,5,5,6,6,6‐nonafluorohexyl group and its application to fluorosilicone synthesis were studied. In contrast to the polymerization of the commercially available 1,3,5‐tris(3,3,3‐trifluoropropyl)‐1,3,5‐trimethylcyclotrisiloxane (CF₃–D3), the polymerization of 1,3,5‐tris(3,3,4,4,5,5,6,6,6‐nonafluorohexyl)‐1,3,5‐trimethylcyclotrisiloxane (C₄F₉–D3) with sodium hydroxide yielded 1,3,5,7‐tetrakis(3,3,4,4,5,5,6,6,6‐nonafluorohexyl)‐1,3,5,7‐tetramethylcyclotetrasiloxane {[C₄F₉CH₂CH₂(CH₃)SiO]₄ (C₄F₉–D4)} as the major product, which was the result of the depolymerization by a backbiting mechanism. On the other hand, the polymerization of C₄F₉–D3 with trifluoromethanesulfonic acid yielded a polymer with good reproducibility, although the distribution of molecular weight tended to be bimodal. C₄F₉–D3 was also successfully copolymerized with octamethylcyclotetrasiloxane (D4). The properties of the obtained copolymers changed almost linearly with the amount of [C₄F₉C₂H₄(CH₃)SiO] units, except for the surface tension. The surface tension of the copolymer containing more than 50% [C₄F₉C₂H₄(CH₃)SiO] units by weight was almost as low as that of the homopolymer. When the copolymer containing 50% [C₄F₉C₂H₄(CH₃)SiO] units by weight was examined for an antifoaming agent, it worked as effectively as the homopolymer in the toluene foaming system. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3333–3340, 2001     

Application of numerical modeling of selective NOx reduction by hydrocarbon under diesel transient conditions in consideration of hydrocarbon adsorption and desorption process

A model of NO_x selective reduction by hydrocarbon (HC) was developed, which takes into account the adsorption and desorption of HC. The model was applied for predicting the performance of a De–NO_x catalytic reactor, working under transient conditions such as a legislative driving cycle. Diesel fuel was used as a supplemental reductant.

The behavior of HC and NO_x reactions and HC adsorption and desorption has been simulated successfully by our numerical approach under the transient conditions of the simulated Japanese 10–15 driving cycle. Our model is expected to optimize the design of selective diesel NO_x reduction systems using a diesel fuel as a supplemental reductant.     

Composition Regulation by Flow Copolymerization of Methyl Methacrylate and Glycidyl Methacrylate with Free Radical Method

It is important to match the feeding ratio of comonomers to the composition ratio in the resulting copolymers as closely as possible in industrial production, where the goal is often to produce more a homogeneous composition in copolymers. In this study, a flow copolymerization system with a conventionally initiated free radical method, together with randomly selected polymerization conditions is investigated. It is succeeded in achieving a closer match between the composition ratio and feeding ratio than previously reported in the copolymerization of styrene with methyl methacrylate and of glycidyl methacrylate with methyl methacrylate, which will widen the range of applications, by precisely controlling the mixing and heating in a flow polymerization apparatus. This is confirmed by the fact that the estimated values of reactivity ratios, r₁ and r₂, which are used in the reaction kinetics of copolymerization, are close to 1.