Reversible and hierarchical composite gels with CdSe nanocrystals

To synthesize composite solid materials of metal salt and CdSe nanocrystals by a simple one-step method has been described. These solids can form stable gel in some organic solvent, such as benzene, cyclohexane and 1-butanol, especial in n-decane even below 0.1 wt/vol.%. Furthermore, these gels appear strong fluorescence which can be easily adjusted by the gel concentration. Temperature-dependent fluorescence spectra of composite gels suggested that the CdSe NCs aggregate together in gel state which would induce the energy transfer between nanocrystals and these aggregates could be reversibly disintegrated when gel was heated to form sol. TEM observations provided the further evidence of the energy transfer and suggested that the CdSe NCs were enchased regularly not only on the surface of self assembly of metal salt, but also embedded inside of self assembly in composite gel with small size nanocrystals. In contrast, in composite organogel with large nanocrystals they were only enchased on the edge of self assembly.     

A comparative study and phage typing of silage-making Lactobacillus bacteriophages

To investigate basic characteristics of 10 virulent phages active on silage-making lactobacilli, morphological properties, host ranges, protein composition and genome characterization were separated into five groups based on host ranges and basic properties. The seven phages of groups I, II and V were active on Lactobacillus plantarum and Lactobacillus pentosus. Phage phiPY4 (group III) infected both L. casei and Lactobacillus rhamnosus. Phage phiPY5 (group IV) specifically infected Lactobacillus casei. Morphologically, three phages of groups I belonged to the Myoviridae family, while seven other phages of groups II, III and V belonged to the Siphoviridae family. SDS-PAGE profiles, restriction analysis, G + C contents of DNA and Dot blot hybridization revealed a high degree of homology in each group. Clustering derived from host range analysis was closely related to results of DNA and protein analyses. These phages may be applicable to phage typing for silage-making lactobacilli.     

1,5-Anhydro-D-fructose Protects against Rotenone-Induced Neuronal Damage In Vitro through Mitochondrial Biogenesis

Mitochondrial functional abnormalities or quantitative decreases are considered to be one of the most plausible pathogenic mechanisms of Parkinson’s disease (PD). Thus, mitochondrial complex inhibitors are often used for the development of experimental PD. In this study, we used rotenone to create in vitro cell models of PD, then used these models to investigate the effects of 1,5-anhydro-D-fructose (1,5-AF), a monosaccharide with protective effects against a range of cytotoxic substances. Subsequently, we investigated the possible mechanisms of these protective effects in PC12 cells. The protection of 1,5-AF against rotenone-induced cytotoxicity was confirmed by increased cell viability and longer dendritic lengths in PC12 and primary neuronal cells. Furthermore, in rotenone-treated PC12 cells, 1,5-AF upregulated peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α) expression and enhanced its deacetylation, while increasing AMP-activated protein kinase (AMPK) phosphorylation. 1,5-AF treatment also increased mitochondrial activity in these cells. Moreover, PGC-1α silencing inhibited the cytoprotective and mitochondrial biogenic effects of 1,5-AF in PC12 cells. Therefore, 1,5-AF may activate PGC-1α through AMPK activation, thus leading to mitochondrial biogenic and cytoprotective effects. Together, our results suggest that 1,5-AF has therapeutic potential for development as a treatment for PD.     

Bioethanol production from xylose by recombinant Saccharomyces cerevisiae expressing xylose reductase, NADP(+)-dependent xylitol dehydrogenase, and xylulokinase

We constructed a set of recombinant Saccharomyces cerevisiae strains with xylose-fermenting ability. A recombinant S. cerevisiae strain D-XR/ARSdR/XK, in which protein engineered NADP(+)-dependent XDH was expressed, showed 40% increased ethanol production and 23% decrease in xylitol excretion as compared with the reference strain D-XR/XDH/XK expressing the wild-type XDH.     

Shield Tunnel Construction in Centrifuge

A large number of centrifuge model tests for simulating the shield construction process in dry sand was carried out by using a newly developed 100 mm diameter miniature shield tunnel. Different construction processes were modeled by three series of tests. A “buried tube test” was conducted to measure the lining stress under a centrifugal acceleration, a “tail void test” simulated the process of tail void formation only, and a “shield test” dealt with the complete process of shield construction. Lining stresses, transverse and longitudinal surface settlements, and earth pressures around the tunnel were simultaneously measured during advancement of the shield at a centrifugal acceleration of 25g. The lining stress at the crown elevation was well predicted by Terzaghi's loosening earth pressure. From the comparison with the recent field measurements and the comparative results of three series of tests, it was confirmed that the shield construction process was successfully simulated in a centrifuge. An experimental formula for estimating the surface settlement above the shield was deduced by a function of tail void thickness and cover-to-diameter ratio.     

Biodiesel fuel production from plant oil catalyzed by Rhizopus oryzae lipase in a water-containing system without an organic solvent

A new enzymatic method of synthesizing methyl esters from plant oil and methanol in a solvent-free reaction system was developed. It is anticipated that such plant oil methyl esters can be used as a biodiesel fuel in the future. Lipase from Rhizopus oryzae efficiently catalyzed the methanolysis of soybean oil in the presence of 4–30 wt% water in the starting materials; however the lipase was nearly inactive in the absence of water. The methyl ester (ME) content in the reaction mixture reached 80–90 wt% by stepwise additions of methanol to the reaction mixture. The kinetics of the reaction appears to be in accordance with the successive reaction mechanism. That is, the oil is first hydrolyzed to free fatty acids and partial glycerides, and the fatty acids produced are then esterified with methanol. Although R. oryzae lipase is considered to exhibit 1(3)-regiospecificity, a certain amount of 1,3-diglyceride was obtained during the methanolysis and hydrolysis of soybean oil by R. oryzae lipase solution. Therefore, the high ME content in the reaction mixture is probably attributable to the acyl migration from the sn-2 position to the sn-1 or sn-3 position in partial glycerides.     

A study of voltage and reactive power control methods for high‐efficiency operation of distribution networks

Transformers with on‐load tap changer and step voltage regulators are most often used for regulating the distribution network voltage. Their use, however, creates certain problems, namely, the voltage control is in discrete steps and the response time is not satisfactory enough. In addition, the power factor (p.f.) compensation relies on capacitors installed by electricity users which creates additional problems manifesting themselves in unexpected overvoltages during light load and increase of power losses. To solve these problems, the authors have proposed a new voltage and p.f. control system for distribution networks based on sophisticated power electronics technology. This paper describes our study on the operating theory of inverter‐controlled regulators and thyristor‐controlled reactors, which play important roles in this system, and the results of simulation through which the usefulness of these equipment has been ascertained. © 1999 Scripta Technica, Electr Eng Jpn, 130(1): 76–87, 2000     

Solution‐processed organic TFT array for active‐matrix LCDs on a plastic substrate

Abstract— Organic TFTs (OTFTs) have been developed with a novel solution‐processed gate insulator of poly(4‐vinylphenol) (PVP) with the addition of octadecyltrichloro‐silane (OTS) and a solution‐processed organo‐silver electrode/wire to improve the performance of an OTFT and to maked high‐throughput‐manufacturing process possible. Solution‐processed PVP has also employed for a buffer layer on a plastic substrate. The OTFT backplane with these solution‐based organic‐material technologies has been successfully applied to drive a 2.5‐in. QQVGA (160 × 120 pixels) AMLCD with a resolution of 79 dpi.     

NOx removal by a pipe with nozzle-plate electrode coronadischarge system

The effects of additional gas composition on the corona discharge characteristics in a pipe with nozzle electrode system and the NOx removal characteristics for flue gases are experimentally investigated. The additional gas consists of a mixture of Na+O₂+NH₃ and a small amount of Ar or CO₂, and is introduced to the flue gas stream from the pipe electrode through the corona discharging zone at the tip of nozzles. The results show that corona discharge characteristics and modes are significantly influenced by the composition of the additional gas mixture. Both NO_x reduction rate and energy yield of NO_x removal increase with decreasing corona discharge input power. NO reduction rate and energy yield can be optimized by the type of the additional gas mixture and the flow rates     

Disproportionation of triethylsilane over CaY zeolite

The disproportionation of triethylsilane over CaY zeolite was examined using a fixed-bed flow reactor. The reactions at 673–723 K gave diethylsilane and tetraethylsilane, the conversion of triethylsilane being 50%. Practically no hydrocarbons were included in the product. The effects of the degree of Ca²⁺ exchange and the reaction variables on the catalytic performance were examined. This revised version was published online in July 2006 with corrections to the Cover Date.