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51.
1.IntroductionAsanewkindofrareearthmolybdenumcathodematerial,MoY2O3isexpectedtosubstituteradioactiveWThO2cathodematerialsinthefuture.Mo4wt%Y2O3allows,relativetoMoLa2O3〔12〕(whichhasbeenwidelystudiedsince1970sinordertosubstituteWThO2cathodemater…  相似文献   
52.
The effect of polyhydric and monohydric alcohols, of phenols, of carboxylic acids and their anions, of halide anions, of alkalimetalions and of some other compounds on the gelatination temperature of potato starch granules in aqueous solutions were studied. Polyhydric alcohols and methanol raise the gelatination temperature, whereas ethanol, propanol, butanol, p-dioxane, carboxylic acids, phenols, urea and hydrogen peroxide cause a decrease in the gelatination temperature. The effect of polyhydric alcohols may be attributed to the lessened tendency of the medium to rupture hydrogen bonds. Carboxylic acids, phenols, urea and hydrogen peroxide may act in a opposite way. The lowering effect of the monohydric alcohols, dioxane, and other non-polar substances may be due to structural and kinetic alterations of the aqueous medium, induced by the non-polar groups. At higher concentrations of ethanol, propanol, p-dioxane, acetic, propionic and butyric acid the gelatination temperature tends to increase. This is to be attributed to the association of solute molecules.  相似文献   
53.
Because starch of low viscosity is important for industrial purposes this research was carried out to study the possibility of producing this sort of starch by treating rice starch with γ-irradiation. Results indicated that when rice starch was modified by γ-irradiation, the reducing power increased and degradation as well as molecular breakdown occured followed by sharp decrease of its viscosity, specific viscosity and intrisinc viscosity. Results showed that starch became more soluble by treating with γ-irradiation and lost its resistance to water as its swelling capacity decreased. All these changes were proportional to the doses of γ-irradiation.  相似文献   
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Peptide DIIADDEPLT (Pep19) has been previously suggested to improve metabolic parameters, without adverse central nervous system effects, in a murine model of diet-induced obesity. Here, we aimed to further evaluate whether Pep19 oral administration has anti-obesogenic effects, in a well-established high-fat diet-induced obesity model. Male Swiss mice, fed either a standard diet (SD) or high-fat diet (HFD), were orally administrated for 30 consecutive days, once a day, with saline vehicle or Pep19 (1 mg/kg). Next, several metabolic, morphological, and behavioral parameters were evaluated. Oral administration of Pep19 attenuated HFD body-weight gain, reduced in approximately 40% the absolute mass of the endocrine pancreas, and improved the relationship between circulating insulin and peripheral insulin sensitivity. Pep19 treatment of HFD-fed mice attenuated liver inflammation, hepatic fat distribution and accumulation, and lowered plasma alanine aminotransferase activity. The inguinal fat depot from the SD group treated with Pep19 showed multilocular brown-fat-like cells and increased mRNA expression of uncoupling protein 1 (UCP1), suggesting browning on inguinal white adipose cells. Morphological analysis of brown adipose tissue (BAT) from HFD mice showed the presence of larger white-like unilocular cells, compared to BAT from SD, Pep19-treated SD or HFD mice. Pep19 treatment produced no alterations in mice behavior. Oral administration of Pep19 ameliorates some metabolic traits altered by diet-induced obesity in a Swiss mice model.  相似文献   
56.
The progeny production and development rates of the nematode Caenorhabditis elegans when treated with deoxynivalenol (DON) were examined. Both purified DON and a crude extract from Fusarium graminearum cultured on rice were tested on C. elegans wild-type (Bristol N2) and a mutant strain (AU1). Significant effects (Tukey-HSD, p<0.05) on brood size and the rate of larval development from egg to adulthood were observed. Both N2 and AU1 strains showed lower rates of development and smaller brood sizes when exposed to purified DON at concentrations of 500 and 1000 μg ml(-1) When they were exposed to crude extract containing 250 μg ml(-1) DON, the inhibition of egg hatching and a greatly reduced development rate were observed. The results suggest that selection of a more sensitive C. elegans mutant strain could be used as a suitable animal model for conducting DON toxicity assays.  相似文献   
57.
The LacLM β-galactosidase of Lactobacillus fermentum K4 is encoded by 2 consecutive genes, lacL (large subunit) and lacM (small subunit), that share 17 overlapping nucleotides. Phylogenetic analysis revealed that this enzyme was closely related to other Lactobacillus β-galactosidases and provided significant insight into its common and distinct characteristics. We cloned both the lacL and lacM genes of L. fermentum K4 and heterologously expressed each in Escherichia coli, although the recombinant enzyme was only functional when both were expressed on the same plasmid. We evaluated the enzymatic properties of this species-specific LacLM β-galactosidase and discovered that it acts as both a hydrolase, bioconverting lactose into glucose and galactose, and a transgalactosylase, generating prebiotic galacto-oligosaccharides (GOS). The recombinant β-galactosidase showed a broad pH optimum and stability around neutral pH. The optimal temperature and Michaelis constant (Km) for the substrates o-nitrophenyl-β-d-galactopyranoside and lactose were, respectively, 40°C and 45 to 50°C and 1.31 mM and 27 mM. The enzyme activity was stimulated by some cations such as Na+, K+, and Mg2+. In addition, activity was also enhanced by ethanol (15%, wt/vol). The transgalactosylation activity of L. fermentum K4 β-galactosidase effectively and rapidly generated GOS, up to 37% of the total sugars from the reaction. Collectively, our results suggested that the β-galactosidase from L. fermentum K4 could be exploited for the formation of GOS.  相似文献   
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59.
Following a linear theory of magneto-thermo-elasticity with thermal relaxation, the propagation of Rayleigh waves in a semi-infinite body permeated by an uniform magnetostatic field parallel to the boundary surface is investigated. It is assumed that the elastic medium under consideration is a homogeneous, isotropic, electrically and thermally conducting one. The roots of the frequency equation are calculated numerically. The approximate solution for small thermoelastic and magnetoelastic coupling is obtained and compared with the exact solution.  相似文献   
60.
Lando M  Shimony Y  Noter Y  Benmair RM  Yogev A 《Applied optics》2000,39(12):1962-1965
Passive Q switching is a preferable choice for switching the Q factor of a solar-pumped laser because it requires neither a driver nor an electrical power supply. The superior thermal characteristics and durability of Cr(4+):YAG single crystals as passive Q switches for lamp and diode-pumped high-power lasers has been demonstrated. Here we report on an average power of 37 W and a switching efficiency of 80% obtained by use of a solar-pumped Nd:YAG laser Q switched by a Cr(4+):YAG saturable absorber. Concentration of the pumping solar energy on the laser crystal was obtained with a three-stage concentrator, composed of 12 heliostats, a three-dimensional compound parabolic concentrator (CPC) and a two-dimensional CPC. The water-cooled passive Q switch also served as the laser rear mirror. Repetition rates of as much as 50 kHz, at pulse durations between 190 and 310 ns (FWHM) were achieved. From the experimental results, the saturated single-pass power absorption of the Cr(4+):YAG device was estimated as 3 ? 1%.  相似文献   
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