Inhibitory effect of chlorophyll c2 from brown algae,Sargassum horneri,on degranulation of RBL-2H3 cells

The anti-allergic effect of alcohol extracts from edible seaweeds was evaluated by the degranulation of a rat basophilic leukemia cell line (RBL-2H3). Extracts prepared from the brown algae Sargassum horneri, Ecklonia cava and Ecklonia kurome, inhibited the degranulation of RBL-2H3 cells, whereas those from green algae and red algae did not. The active substance in S. horneri was purified and identified as chlorophyll c2, a major pigment in brown algae. The purified chlorophyll c2 preparation also suppressed the degranulation of RBL-2H3 cells. In contrast, chlorophyll a and b did not affect cell degranulation. Therefore, chlorophyll c2 from brown algae might be useful for the prevention or mitigation of allergic symptoms.     

Fracture Model of Fine Bulk Powder Structures

ABSTRACT

Using several line powders (particle size 15-65 μ m). the rheological parameters of tensile strength ( σ_f,mb) and plastic deformation coefficient (Y) were experimentally measured at ambient and elevated temperatures. In order to be aeratable. the rheological parameters of a specific powder should satisfy the equation of σ_f,mb = 0.11Y^{0 89.}The formation of agglomerates or dead zones can be predicted. By introducing the “Quasi porous solid body model,” the theoretical derivation of the criterion characteristic curve was accomplished using solid fracture theory.     

Regional instability evaluation of Ringhals unit 1 based on extended frequency domain model

The frequency domain model has been extended for the regional instability evaluation while retaining its practicality and improving the reliability of major influential numerical models. The unified friction and local pressure loss model of the original LAPUR was modified considering the different dynamic characteristic of two pressure loss mechanisms. The detailed ex-core recirculation loop model was implemented and the neutron point kinetics model was also modified to reflect the inter-mode void reactivity interaction. The neutron flux modal analysis code, ACCORD-N, was developed based on the nonlinear iterative nodal method. Efficient schemes were proposed to give the higher mode initial flux guess. The modified code system was verified based on the Ringhals unit 1 stability test data. Extensive studies were performed to identify influential factors in the regional instability. A dependence of the decay ratio was investigated with regard to the sub-criticality of the first azimuthal mode, Nyquist plots and several power shape indices. It seemed reasonable to conclude that the regional instability was strongly influenced by the thermal hydraulic mechanism. Including the simulation results of other reactors, the distance weighted axial power momentum, named the AS-value, gave a good account of both core-wide and regional instability modes.     

Generation of uniform tetrapod-shaped zincoxide nanoparticles by gas-phase reaction with using flow restrictor

Tetrapod-shaped ZnO particles are generated via gas-phase reaction of Zn vapor and oxygen in air, where they undergo homogeneous nucleation from supersaturated ZnO vapor and successive growth by surface reaction. It was found that a simple device for flow restrictor is effective in making ZnO particles of terapod-shape by leaving sufficient amounts of unreacted Zn vapor with the embryos of ZnO. In the absence of the flow restrictor, only spherical particles are formed because the oxidation reaction takes place immediately after mixing and unreacted Zn vapor does not remain for the subsequent crystal growth. The Zn vapor concentration distribution, oxygen concentration distribution, temperature, gas velocity and reaction rate in the reactor were analyzed by using a conventional computational fluid dynamic simulation package. The simulation revealed that the flow restrictor does not enhance mixing between Zn vapor and air but suppresses the mixing and reduces the residence time in the reactor so that sufficient amounts of unreacted Zn vapor remain downstream of the flow restrictor, allowing ZnO particles to grow in tetrapod-shape by abnormal crystal growth.     

YHp as a highly stable,hyper-copy,hyper-expression plasmid constructed using a full 2-μm circle sequence in cir0 strains of Saccharomyces cerevisiae

In the yeast Saccharomyces cerevisiae, the yeast episomal plasmid (YEp), containing a partial sequence from a natural 2-μm plasmid, has been frequently used to induce high levels of gene expression. In this study, we used Japanese sake yeast natural cir⁰ strain as a host for constructing an entire 2-μm plasmid with an expression construct using the three-fragment gap-repair method without Escherichia coli manipulation. The 2-μm plasmid contains two long inverted repeats, which is problematic for the amplification by polymerase chain reaction. Therefore, we amplified it by dividing into two fragments, each containing a single repeat together with an overlapping sequence for homologous recombination. TDH3 promoter-driven yEmRFP (TDH3p-yEmRFP) and the URA3 were used as a reporter gene and a selection marker, respectively, and inserted at the 3′ end of the RAF1 gene on the 2-μm plasmid. The three fragments were combined and used for the transformation of sake yeast cir⁰ ura3^- strain. The resulting transformant colonies showed a red or purple coloration, which was significantly stronger than that of the cells transformed with YEp-TDH3p-yEmRFP. The 2-μm transformants were cultured in YPD medium and observed by fluorescence microscopy. Almost all cells showed strong fluorescence, suggesting that the plasmid was preserved during nonselective culture conditions. The constructed plasmid maintained a high copy state similar to that of the natural 2-μm plasmid, and the red fluorescent protein expression was 54 fold compared with the chromosomal integrant. This vector is named YHp, the Yeast Hyper expression plasmid.     

An Investigation of Microstructure and Phase Transformation Behavior of Cu40Zn-1.0 wt.% Ti Brass Via Powder Metallurgy

The effects of Ti addition on phase transformation, precipitation behavior, and microhardness response of Cu40Zn brass were investigated at elevated heat treatment (HT) temperatures using the powder metallurgy method. The volume fraction of the α phase increased with the elevated temperatures, which showed an equal value as that of the β phase at 400 °C, and reached a maximum value of 55.9% at 500 °C. The solid solubility of Ti in Cu40Zn brass matrix decreased as the HT temperature increased. Supersaturated Ti showed high chemical potential for precipitates' reaction in Cu40Zn brass. Lower HT temperature retained higher Ti solid solubility and fine precipitates. The precipitates presented in form of Cu₂TiZn intermetallic compound, distributing uniformly in brass matrix which suppressed the phase and grain growth. After HT at elevated temperature, the precipitates coalesced, grew coarser, and segregated at the primary particle boundaries. The microhardness of the BS40-1.0Ti compact was primarily not only dependent on the solid solubility of Ti, but also dependent on the phase volume fraction of the α and β phases.     

Moderation of oxonate-induced hyperuricemia in rats via the ingestion of an ethanol-soluble fraction of a shark cartilage proteolytic digest

A shark cartilage proteolytic digest was fractionated by selective extraction with 75% ethanol. Peptides in the digest were recovered in the 75% ethanol-soluble fraction. The ethanol-soluble fraction showed lower viscosity and higher solubility in water than the crude digest. Oxonate-induced hyperuricemia in rat was suppressed by the oral administration of the ethanol-soluble fraction of the digest (1 g/kg body weight/day) for 28 days. Single administration of the ethanol-soluble fraction also reduced blood uric acid level in a dose-dependent manner. Administration of the ethanol-soluble fraction of the digest (1 g/kg body weight/day) significantly increased serum inhibitory activity against xanthine oxidase, whereas the ethanol-soluble fraction had no in vitro xanthine oxidase inhibitory activity. These facts suggest that peptides in the ethanol-soluble fraction might be converted into smaller peptides with xanthine oxidase inhibitory activity during digestion, absorption, and metabolism.     

Load dependence of soft actuators based on polypyrrole tubes

Isotonic load stress dependence of biomimetic soft actuators based on polypyrrole tubes has been studied to elucidate the work behaviour. Polypyrrole (PPy) tubes were electrochemically prepared on gold coated acryl resin in an aqueous solution of pyrrole and dodecylbenzensulfonic acid (DBS). The tubes were operated electrochemically in aqueous 1 M LiCl, and the change of tube length was measured under various load stresses. It was found that with increasing load stresses the response time slowed down and the contraction ratio reduced. Hence, the current decreased and lasted longer, indicating that the tube was sensing the load stress. During contraction of the tube, the conversion efficiency was estimated from the electrical input and mechanical output energies to be 0.12%. The maximum volumetric work was approximately 120 kJ/m³. The results were discussed taking the dynamics of ion migration into consideration.     

Improving antioxidant activity and nutritional components of Philippine salt-fermented shrimp paste through prolonged fermentation

The antioxidant activity and nutritional components of Philippine salt-fermented shrimp paste were improved through prolonged fermentation (90, 180, and 360 days). The antioxidant ability against 1,1-diphenyl-2-picryhydrazyl (DPPH) radical, hydrogen peroxide, and lipid peroxidation increased significantly with prolonged fermentation and were suggested to be related with the Maillard reaction products formed, as measured by the characteristic browning and fluorescent developments. Polyunsaturated fatty acids like eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in the shrimp paste were not substantially damaged for 360 days, while free amino acid content dramatically increased at 90 days. However, excessive fermentation showed slight but significant decrease in free amino acids and increase in ammonia. These results suggest that properly prolonged fermentation would improve antioxidant ability and some nutritional value in the salt-fermented shrimp paste.     

日本の寒地，北海道の稲作限界地帯におけるもち米の精米蛋白質含有率および米粒白度の年次間地域間差異とその発生要因 (日语原文)

北海道では，もち米は最も冷涼な稲作地帯で生産される。その作柄が大きく変動した4カ年の6栽培地域で，年次間では，障害型冷害危険期の気温が高く不稔歩合が低く，また出穂後40日間の日平均積算気温（登熟気温）が高く千粒重が重く多収なほど，低蛋白となり玄米と精米の白度は高くなった。一方，地域間では，これらの関係が概して明確ではなかった。このことは年次間の最小値最大値の差異および変動係数が地域間に比べ，精米蛋白質含有率（蛋白質）では1.0，1.3倍と同じかやや大きく，生育期別気温や生育特性では1.3~8.5倍，米粒の両白度でも1.6~2.6倍と大きいためであった。なお，蛋白質は登熟気温が年次地域込みで849 ℃で最低となる二次回帰を示した。また，年次と地域の各平均値が，障害型冷害危険期の平均気温で低く不稔歩合で高く，千粒重で軽く玄米収量で低く，蛋白質で高く米粒両白度で低く，すなわちそれらが不良なほど，年次では地域間，地域では年次間における変動係数が大きかった。さらに，米粒の両白度はいずれも1 m2の１籾当たりの登熟気温との間に正の相関関係を示し，目標の玄米白度を得るための同1籾当たり登熟気温および目的地域の平年の登熟気温からm2当たりの籾数を求めることにより，目標の玄米白度を得るための施肥窒素量が算定できた。