Application of microalgae hydrolysate as a fermentation medium for microbial production of 2-pyrone 4,6-dicarboxylic acid

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Lipid-Lowering Effect of Eriocitrin, the Main Flavonoid in Lemon Fruit, in Rats on a High-Fat and High-Cholesterol Diet

ABSTRACT:  Eriocitrin (eriodictyol 7- O -β-rutinoside) is the main flavonoid in lemon fruit. In this study, eriocitrin was investigated for its lowering effect on serum and hepatic lipids in high-fat and high-cholesterol fed rats. Rats in the control group ( N = 6) were fed a 20% lard and 1% cholesterol diet for 21 d, and rats in the 0.35% eriocitrin group ( N = 6) and 0.70% eriocitrin group ( N = 6) were fed a diet supplemented with eriocitrin 0.35% and 0.70%, respectively. The content of hepatic total cholesterol and triglyceride in the eriocitrin group was no different from that of the control group. The total cholesterol, VLDL+LDL, triglyceride, and phospholipid in the serum of the 0.35% eriocitrin group showed significantly lower concentrations than the control group ( P < 0.05), although there was no difference in the HDL concentrations among the groups. The lowering effect of eriocitrin for serum total cholesterol was thought to be caused by a decrease in VLDL+LDL. The 0.35% eriocitrin group was shown to have a significant increase in excretion of fecal bile acid ( P < 0.05) and a tendency for enhanced hepatic m-RNA levels of LDL receptor in comparison with the control group.     

Simultaneous determination of five penicillins in muscle,liver and kidney from slaughtered animals using liquid chromatography coupled with electrospray ionization tandem mass spectrometry

A simple and rapid method for the simultaneous determination of five penicillins (ampicillin, penicillin G, penicillin V, oxacillin and cloxacillin) in muscle, liver and kidney tissues using high-performance liquid chromatography-electrospray tandem mass spectrometry (LC-ESI-MS/MS) was developed. Mass spectral acquisition was done in the negative ion mode by applying selected reaction monitoring (SRM). The five penicillins were extracted with water, and the extracted solution was cleaned up on a C18 cartridge. Phenethicillin was added as an internal standard, and the extract was diluted with water for injection into the LC-ESI-MS/MS. The recoveries of the five penicillins were in the range of 77.3-99.8% from muscle, liver and kidney fortified at 10-250 ng/g. The detection limits for ampicillin were 6 ng/g in muscle and kidney and 15 ng/g in liver. For penicillin G and penicillin V, the detection limits were 2 ng/g in muscle and kidney and 5 ng/g in liver. For oxacillin and cloxacillin, the detection limits were 4 ng/g in muscle and kidney and 10 ng/g in liver. Twenty-three muscle, fourteen liver and twenty-two kidney samples from the markets were analyzed by this method. No penicillins were detected in any sample.     

Contamination levels of PCDDs, PCDFs and Co-PCBs in commercial baby foods in Japan

To examine dioxin contamination in commercial baby foods in Japan, congener analyses of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and coplanar polychlorinated biphenyls (Co-PCBs) were performed on 102 varieties of baby foods obtained from supermarkets in 2001-2002. The toxic equivalent quantity (TEQ) levels for dioxins in samples ranged from < 0.001 to 0.135 pg-TEQ/g wet weight when undetected or trace levels of congeners were taken as zero. Among 102 samples tested, 26 samples exceeded 0.010 pg-TEQ/g. The highest TEQ value was for "sardine, vegetables" (0.135 pg-TEQ/g), followed by "Japanese radish (daikon), sardine" (0.080 pg-TEQ/g). Thus, dioxins were detected at low levels in baby foods containing animal products such as fishes and/or dairy products.     

Inter-laboratory validation studies of biological method for determination of streptomycin in royal jelly

Inter-laboratory validation studies were conducted in 6 laboratories to validate the biological method for determination of streptomycin in royal jelly. Streptomycin spiked at the level of 0.2 and 1.0 ppm was analyzed. Mean recoveries were 89 and 96%, reproducibility relative standard deviations (RSD(R)) were 15.0 and 14.0%, HORRAT(R) values were 0.7 and 0.9. Samples containing residues at the levels of 0.25 and 0.80 ppm were analyzed. Mean recoveries were 113 and 99%, RSD(R) were 15.0 and 10.4%, and HORRAT(R) values were 0.8 and 0.6. The determination limit was 0.1 ppm. These results show that this method has good performance.     

Responses of maxillary sensilla styloconica inBombyx mori to glucosides fromOsmunda japonica,a nonhost plant

We isolated glucosides from the royal fern,Osmunda japonica, which elicit a deterrent response in larvae ofBombyx mori. These compounds were absent in taro (Colocasia antiquorum) and castor-oil plant (Ricinus communis) leaves and did not evoke responses of sensory cells in the lateral and medial sensilla styloconica ofSpodoptera litura. This glucoside extract of the royal fern leaves stimulates receptors generally associated with deterrent. It is also possible that this compound may act as a behavioral deterrent, and from actual feeding tests, it is suggested that this compound may prevent feeding in some monophagous insects, such asBombyx mori. The deterrent glucoside possesses a noncyclic aglycon.     

Radical polymerization of (phenylethynyl)styrenes and characterization of poly(phenylethynyl)styrenes as a thermally curable material

Summary The radical polymerizations of 2-, 3-, and 4-(phenylethynyl)styrenes (1a–c) and the copolymerizations of 1a–c (M₁) with styrene (M₂) were carried out using AIBN as the initiator in toluene at 60°C. The number-average molecular weights (M _ns) were extremely low for poly(2-phenylethynylstyrene) (2a) and poly[(phenylethynyl)styrene-co-styrene] (3a), and increased in the order of 2a, 3a << 2b, 3b < 2c, 3c. Monomer reactivity ratios were determined as r ₁= 1.80 and r ₂= 0.51 for 1a, r ₁= 1.72 and r ₂= 0.53 for 1b, and r ₁= 3.17 and r ₂= 0.24 for 1c. Polymers 2a–c and 3a–c underwent an exothermic reaction at elevated temperature to form organic solvent-insoluble polymers. Although the decomposition of 2a was observed from 200°C, 2b and 2c exhibited a high heat-resistance property in both nitrogen and air atmospheres, in particular, 2b showed no significant weight loss below 450°C. Received: 28 January 1998/Accepted: 5 March 1998     

Microstructural Design of Silicon Nitride with Improved Fracture Toughness: II, Effects of Yttria and Alumina Additives

Significant improvements in the fracture resistance of self-reinforced silicon nitride ceramics have been obtained by tailoring the chemistry of the intergranular amorphous phase. First, the overall microstructure of the material was controlled by incorporation of a fixed amount of elongated ß-Si₃N₄ seeds into the starting powder to regulate the size and fraction of the large reinforcing grains. With controlled microstructures, the interfacial debond strength between the reinforcement and the intergranular glass was optimized by varying the yttria-to-alumina ratio in the sintering additives. It was found that the steady-state fracture toughness value of these silicon nitrides increased with the Y:Al ratio of the oxide additives. The increased toughness was accompanied by a steeply rising R -curve and extensive interfacial debonding between the elongated ß-Si₃N₄ grains and the intergranular glassy phase. Microstructural analyses indicate that the different fracture behavior is related to the Al (and O) content in the ß´-SiAlON growth layer formed on the elongated ß-Si₃N₄ grains during densification. The results imply that the interfacial bond strength is a function of the extent of Al and Si bonding with N and O in the adjoining phases with an abrupt structural/chemical interface achieved by reducing the Al concentration in both the intergranular phase and the ß´-SiAlON growth layer. Analytical modeling revealed that the residual thermal expansion mismatch stress is not a dominant influence on the interfacial fracture behavior when a distinct ß´-SiAlON growth layer forms. It is concluded that the fracture resistance of self-reinforced silicon nitrides can be improved by optimizing the sintering additives employed.     

A study on the preparation of supported metal oxide catalysts using JRC-reference catalysts. I. Preparation of a molybdena–alumina catalyst. Part 4. Preparation parameters and impact index

The effects of the volume and pH of the impregnation solution and of the calcination conditions were examined on the physicochemical and catalytic properties of a 13 wt% MoO₃/Al₂O₃ extrudate catalyst. The Al₂O₃ support and drying procedures (static conditions without flowing air) were fixed in the preparations. In the present series of catalysts, the amount of crystalline MoO₃ was marginally small. It was found that the dispersion of Mo oxide species increased as the volume of the impregnation solution increased, gradually approaching a maximum value. The increase in pH (2–8) of the impregnation solution was found to reduce the dispersion of Mo oxide species. The Mo dispersion increased slightly for the impregnation catalysts as the calcination temperature increased (673–873 K), whereas it decreased for the equilibrium adsorption catalysts. The effects of the calcination atmosphere (with or without flowing air, or with flowing humid air) were very small on the dispersion of Mo oxide species under the present preparation conditions. On the other hand, the methanol oxidation activity of MoO₃/Al₂O₃ was sensitive to the preparation parameters examined here. It was demonstrated by means of EPMA and XPS that a considerable migration of Mo took place during the calcination.

In the present study on the preparation of a 13 wt% MoO₃/Al₂O₃ catalyst, an impact index is proposed to measure the magnitude of the effects of the respective parameter(s) on the physicochemical and catalytic properties. With the Mo dispersion, the effects of the preparation parameter decreased in the order, surface area of the support >> drying process > volume of the impregnation solution > pH, calcination temperature and atmosphere. The size of the impact index for the dispersion of Mo sulfide species is 70–75% of that for the Mo oxide species. The HDS activity of the catalyst was less affected by the preparation parameters than the Mo sulfide dispersion. The preparation parameters affected the segregation of Mo on the outer surface of extrudates in a decreasing order: drying process > volume of the impregnation solution > pH, calcination conditions. It was found that the oxidation of methanol was affected most intensely by the drying procedures. The volume of the impregnation solution, calcination conditions and pH of the impregnation solution also strongly affected the oxidation activity. The impact index suggests that the sensitivity to the preparation variables of the physicochemical and catalytic properties of MoO₃/Al₂O₃ decreases in the order, methanol oxidation activity > surface Mo segregation > Mo oxide dispersion > Mo sulfide dispersion > HDS activity.     

Mie scattering from sphere structures in polymer blends

Polymer blends of transparent poly(methyl methacrylate) and polystyrene become opaque due to light scattering at the boundaries of the two polymers. The polymer blend is light brown when it is illuminated by white light. The coloring depends on the spherical domain structures existing in the polymer blend. The coloring was analyzed by using the rigorous Mie theory. The Mie results were compared with the semiempirical results previously reported by the authors. The wavelength dependence of theoretical scattering efficiencies on radii of scattering spheres from 0.05 to 1.2 μm was obtained for polystyrene spheres in poly(methyl methacrylate) matrix, and vice versa. The scattering at the short wavelength region is stronger than at the long wavelength region. The scattering efficiencies become almost constant in the visible wavelength region for sufficiently large spheres.