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31.
Strains of Leuconostoc lactis SHO-47 and Le. lactis SHO-54, producing the clinically useful enzyme NAD-specific 6-phosphoglucanate dehydrogenase, were cultivated with a hydrolyzed birch wood xylan as the unique carbon source to produce D-lactic acid for poly(D-lactic acid). In addition to the strains SHO-47 and SHO-54, Lactococcus lactis IO-1, well known as a good xylose-utilizing lactic acid bacterium, was used as a control to confirm the extent of hemicellulose hydrolysis. The fermentation time for lactic acid of strains SHO-47 and SHO-54 was 12 h, and produced respectively 2.3 and 2.2 g/l lactic acid from 8.5 g/l hydrolyzed xylan, whereas the fermentation time of strain IO-1 was 21 h, and produced 1.3 g/l lactic acid. Xylooligosaccharides from xylobiose to xylohexose were utilized more rapidly than xylose in the cultures of strains SHO-47 and SHO-54. However, xylose concentration increased temporarily and then decreased in the culture of strain IO-1. On the other hand, xylooligosaccharides larger than xyloheptaose were not utilized by these three strains. The xylosidase activities of SHO-47, SHO-54, and IO-1 were induced by xylose or a mixture of xylobiose and xylotriose. The xylosidases of these three strains were localized in their cytoplasm. 相似文献
32.
Miwa N Kashiwagi M Kawamori F Masuda T Sano Y Hiroi M Kurashige H 《Shokuhin eiseigaku zasshi. Journal of the Food Hygienic Society of Japan》2006,47(2):41-45
The incidence and levels of Vibrio parahaemolyticus and thermostable direct hemolysin gene (tdh)-positive organisms in retail seafood were determined. The most probable number-polymerase chain reaction (MPN-PCR) method using a PCR procedure targeting the species-specific thermolabile hemolysin gene (tlh) and tdh was used to determine the levels of V. parahaemolyticus and tdh-positive organisms, respectively. In seafood for raw consumption, V. parahaemolyticus was found in four (13.3%) of 30 fish samples, 11 (55.0%) of 20 crustacean samples, and 29 (96.7%) of 30 mollusc samples. Levels of V. parahaemolyticus were below 10(4) MPN/100 g in all fish and crustacean samples tested. However, they were above 10(4) MPN/100 g in 11 (36.7%) of the 30 mollusc samples. In all seafood for raw consumption, the level of tdh-positive organisms was below the limit of detection (< 30 MPN/100 g). In seafood for cooking, V. parahaemolyticus was found in 15 (75.0%) of 20 fish samples, nine (45.0%) of 20 crustacean sample, and 20 (100%) of 20 mollusc samples. Levels of V. parahaemolyticus were above 10(4) MPN/100 g in only three (15.0%) and one (5.0%) of the 20 fish and 20 crustacean samples, respectively. However, they were above 10(4) MPN/100 g in 18 (90.0%) of the 20 mollusc samples. In seven (35.0%) of the 20 mollusc samples, tdh-positive organisms were found and their levels ranged from 3.6x10 to 1.1 x 103 MPN/100 g. From four of seven tdhpositive samples, tdh-positive V. parahaemolyticus was isolated. 相似文献
33.
Chunlei Wan Yifeng Wang Ning Wang Wataru Norimatsu Michiko Kusunoki Kunihito Koumoto 《Science and Technology of Advanced Materials》2010,11(4)
Thermal conductivity is one of the key parameters in the figure of merit of thermoelectric materials. Over the past decade, most progress in thermoelectric materials has been made by reducing their thermal conductivity while preserving their electrical properties. The phonon scattering mechanisms involved in these strategies are reviewed here and divided into three groups, including (i) disorder or distortion of unit cells, (ii) resonant scattering by localized rattling atoms and (iii) interface scattering. In addition, we propose construction of a ‘natural superlattice’ in thermoelectric materials by intercalating an MX layer into the van der Waals gap of a layered TX2 structure which has a general formula of (MX)1+x(TX2)n (M=Pb, Bi, Sn, Sb or a rare earth element; T=Ti, V, Cr, Nb or Ta; X=S or Se and n=1, 2, 3). We demonstrate that one of the intercalation compounds (SnS)1.2(TiS2)2 has better thermoelectric properties compared with pure TiS2 in the direction parallel to the layers, as the electron mobility is maintained while the phonon transport is significantly suppressed owing to the reduction in the transverse phonon velocities. 相似文献
34.
Kimikazu Sasa Tsutomu Takahashi Yuki Tosaki Yuki Matsushi Keisuke Sueki Michiko Tamari Takahiro Amano Toshiyuki Oki Shozo Mihara Yoshihiro Yamato Yasuo Nagashima Kotaro Bessho Norikazu Kinoshita Hiroshi Matsumura 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2010,268(7-8):871-875
We present the current status and research programs of a multinuclide accelerator mass spectrometry (AMS) system on the 12UD Pelletron tandem accelerator at the University of Tsukuba (Tsukuba AMS system), Japan. A maximum terminal voltage of 12 MV is available for the AMS system. The Tsukuba AMS system can measure environmental levels of long-lived radioisotopes of 14C, 26Al, 36Cl and 129I by employing a molecular pilot beam. Recently, enhancements in AMS techniques and equipment, including sample preparation, the ion source and the data acquisition system, have improved the performance of 36Cl-AMS. The standard deviation of fluctuations is typically ±2%, and the machine background level for the 36Cl/Cl ratio is lower than 1 × 10?15 with a halite sample. We have measured over 500 samples in 1 year, including samples for earth and environmental sciences and nuclear safety research. 相似文献
35.
The substrate specificity of rat brain neurolysin was rapidly modified by semirational mutagenesis coupled with a yeast molecular display system. Neurolysin mainly recognizes substrates with sequential six residues close to the scissile bond in polypeptides, cleaving a peptide bond in the center position of the six residues. To alter the recognition of the P2' amino acid of substrates by neurolysin, six residues of neurolysin, Asp467, Arg470, Glu510, Tyr606, Tyr610 and Tyr611, which might be involved in the formation of the neurolysin S2' subsite, were individually and comprehensively substituted. The protein libraries of mutant neurolysins comprising 120 species were displayed on the yeast cell surface and screening was carried out using two fluorescence-quenching peptides, the matrix metalloproteinase-2/9- (MMPs-2/9-) and MMP-3-specific substrates, which consisted of similar amino acids, except for alanine (for MMPs-2/9) or glutamic acid (for MMP-3) at the P2' amino acid position. Among mutant neurolysins, the Y610L mutant neurolysin exhibited a marked change in substrate specificity. Steady-state kinetic analysis of the purified Y610L mutant neurolysin revealed that the binding efficiency toward the MMP-3-specific substrate was about 3-fold higher than that toward the MMP-2/9-specific substrate. These results indicate that Tyr610 of neurolysin is the important residue to recognize the P2' amino acid of substrates. 相似文献
36.
Naoko Yamaoka Harunori Yoshida Mitsuo Tanabe Michiko Yamashita Takuma Koga 《Building Simulation》2008,1(2):118-128
The heat island effect is an important issue for large cities, especially those located in hot and moist climates. The phenomenon
is more severe in urban canyons because surrounding high-rise buildings allow little ventilation and dissipation of heat caused
by traffic. The primary goal of the present study is to investigate the thermal environment of a major street in Osaka by
intensive measurement during the summer of 2006. Osaka is the second largest city in Japan and suffers from the most severe
heat island effect. In addition, several fundamental renovations and a composite renovation for the improvement of thermal
environment in the urban canyon are proposed, and the efficacies of these measures are verified by computational fluid dynamics
(CFD) simulation. It was found that by modifying the heights of buildings along the street and the ground surface materials
and increasing the quantity of vegetation, the thermal environment can be improved by a 2.0°C. reduction in standard new effective
temperature (SET*) at maximum. 相似文献
37.
Fukunori Izumida Rongbin Ye Koji Ohta Mamoru Baba Michiko Kusunoki 《IEEJ Transactions on Electrical and Electronic Engineering》2012,7(4):436-437
To use carbon nanotubes (CNTs) as anode material for the solid‐state thin‐film Li‐ion rechargeable battery, the tubes are preferred to be aligned perpendicular to a substrate and the CNT thin film to have a smooth surface. Using an Ar‐ion sputtering technique, we carried out the surface modifications of the CNT thin film prepared by the SiC surface decomposition method. In order to evaluate the surface modification, the surface and cross section of the modified CNT film were investigated by field‐emission scanning electron microscopy and atomic force microscopy. © 2012 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. 相似文献
38.
Shionoiri N Sato T Fujimori Y Nakayama T Nemoto M Matsunaga T Tanaka T 《Journal of Bioscience and Bioengineering》2012,113(5):580-586
This study demonstrated the antiviral properties of copper iodide (CuI) nanoparticles against the non-enveloped virus feline calicivirus (FCV) as a surrogate for human norovirus. The effect of CuI nanoparticles on FCV infectivity to Crandell-Rees feline kidney (CRFK) cells was elucidated. The infectivity of FCV to CRFK cells was greatly reduced by 7 orders of magnitude at 1000μgml(-1) CuI nanoparticles. At the conditions, electron spin resonance (ESR) analysis proved hydroxyl radical production in CuI nanoparticle suspension. Furthermore, amino acid oxidation in the viral capsid protein of FCV was determined by nanoflow liquid chromatography-mass spectrometric (nano LC-MS) analysis. The use of CuI nanoparticles showed extremely high antiviral activity against FCV. The high antiviral property of CuI nanoparticles was attributed to Cu(+), followed by ROS generation and subsequent capsid protein oxidation. CuI nanoparticles could be proposed as useful sources of a continuous supply of Cu(+) ions for efficient virus inactivation. Furthermore, this study brings new insights into toxic actions of copper iodide nanoparticles against viruses. 相似文献
39.
Nakai M Ito J Sato K Noguchi J Kaneko H Kashiwazaki N Kikuchi K 《Reproduction (Cambridge, England)》2011,142(2):285-293
In pigs, although ICSI is a feasible fertilization technique, its efficiency is low. In general, injected pig sperm are insufficient to induce oocyte activation and embryonic development. Pretreatments for disrupting sperm membranes have been applied to improve the fertility of ICSI oocytes; however, we hypothesize that such pretreatment(s) may reduce the ability of the sperm to induce oocyte activation. We first evaluated the effects of sperm pretreatments (sonication (SO) to isolate the sperm heads from the tails, Triton X-100 (TX), and three cycles of repeated freezing/thawing (3×-FT) for disrupting sperm membranes) on the rate of pronucleus (PN) formation after ICSI. We found that oocytes injected with control (whole) sperm had higher rates of PN formation than those obtained after subjecting the sperm to SO, TX, and 3×-FT. The amounts of phospholipase Cζ (PLCζ), which is thought to be the oocyte-activating factor in mammalian sperm, in sperm treated by each method was significantly lower than that in whole untreated sperm. Furthermore, using immunofluorescence, it was found that in pig sperm, PLCζ was localized to both the post-acrosomal region and the tail area. Thus we demonstrated for the first time that sperm pretreatment leads to a reduction of oocyte-activating capacity. Our data also show that in addition to its expected localization to the sperm head, PLCζ is also localized in the tail of pig sperm, thus raising the possibility that injection of whole sperm may be required to attain successful activation in pigs. 相似文献
40.
Shohei Ueta Jun AiharaKazuhiro Sawa Atsushi YasudaMasaki Honda Noboru Furihata 《Progress in Nuclear Energy》2011,53(7):788-793
This paper describes experiences and present status of research and development works for the high temperature gas-cooled reactor (HTGR) fuel in Japan. Recently, Very High Temperature Reactor (VHTR) is evaluated highly worldwide, and is a principal candidate for the Generation IV reactor systems. In Japan, HTGR fuel fabrication technologies have been developed through the High Temperature Engineering Test Reactor (HTTR) project in Japan Atomic Energy Agency since 1960’s. In total about 2 tons of uranium of the HTTR fuel has been fabricated successfully and its excellent quality has been confirmed through the long-term high temperature operation. Based on the HTTR fuel technologies, SiC TRISO fuel has been newly developed for burnup extension targeted VHTR. For ZrC-TRISO coated fuel as an advanced fuel designs, R&Ds for fabrication and inspection have been carried out in JAEA. The irradiation with the Japanese uniform stoichiometric ZrC coating has been completed in the cooperation with Oak Ridge National Laboratory of the United States. 相似文献