Activities in Cu2S-FeS-PbS melts at 1200 °C

The dew-point method was used to determine the vapor pressures of PbS over liquid sulfides of the system Cu₂S-FeS-PbS at 1200 °C. From the PbS activity data, activities of Cu₂S and FeS were evaluated both in binary and ternary melts by Gibbs-Duhem calculations. The systems Cu₂S-PbS and Cu₂S-FeS exhibit negative departures from ideal behavior, while the FeS-PbS melts are ideal solutions at 1200 °C.     

Changes in lipids in liver and serum of rats fed a histidine-excess diet or cholesterol-supplemented diets

The influence of dietary excess (5%) L-histidine on serum and liver lipids was examined in rats. Feeding a histidine-excess diet for 3, 6, 14 or 30 days caused growth retardation, hepatomegaly and decreased liver lipids throughout the period of the experiment. Hypercholesterolemia was observed after feeding a histidine-excess diet for 6 days; then serum cholesterol continuously increased for 30 days. Serum triglyceride on day 30 in rats fed the histidine-excess diet showed a significant decrease compared to rats fed the basal diet. Serum phospholipids of rats fed the histidine-excess diet for 7 or 14 days showed a significant increase compared to rats fed the basal diet. When rats were fed a basal, histidine-excess or cholesterol-supplemented diet (0.5% and 1.0% cholesterol) for 6 days, the distribution of serum high density (HDL), low density (LDL) and very low density lipoprotein cholesterol in rats fed the histidine-excess diet was similar to that of rats fed the basal diet, whereas LDL-cholesterol increased and HDL-cholesterol decreased in rats fed the cholesterol-supplemented diet.     

Enhancing Wear Resistance of 100Cr6 Bearing Steels by New Heat Treatment Method

Metallurgical and Materials Transactions A - The typical final microstructure of bearing steels is composed of coarse carbides in a martensitic matrix due to coarse carbides in the initial...     

Variations of emotional display rules within and across cultures: A comparison between Canada, USA, and Japan.

This study investigates emotional display rules for seven basic emotions. The main goal was to compare emotional display rules of Canadians, US Americans, and Japanese across as well as within cultures regarding the specific emotion, the type of interaction partner, and gender. A total of 835 university students participated in the study. The results indicate that Japanese display rules permit the expression of powerful (anger, contempt, and disgust) significantly less than those of the two North American samples. Japanese also think that they should express positive emotions (happiness, surprise) significantly less than the Canadian sample. Furthermore, Japanese varied the display rules for different interaction partners more than the two North American samples did only for powerful emotions. Gender differences were similar across all three cultural groups. Men expressed powerful emotions more than women and women expressed powerless emotions (sadness, fear) and happiness more than men. Depending on the type of emotion and interaction partner some shared display rules occurred across culture and gender. The implications of these findings are discussed in relation to cultural dimensions and other cultural characteristics. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Ab initio molecular orbital calculations on specific interactions between urokinase-type plasminogen activator and its receptor

Cancer invasions and metastases are controlled by various proteases. In particular, the binding of urokinase-type plasminogen activator (uPA) to the uPA receptor (uPAR) existing on the surface of cancer cell is considered to be a trigger for cancer invasions. In the present study, we determined the structure of uPA and uPAR complex in water and investigated the specific interactions between uPA and uPAR by ab initio molecular orbital (MO) calculations based on fragment MO method. The result indicates that the 20–26 amino acid residues of uPA are important for the binding between uPA and uPAR, and that the electrostatic interactions between the charged amino acid residues existing in both uPA and uPAR have large contribution to the binding. The influence of crystal water molecules existing between uPA and uPAR was also investigated to be significant on the specific interactions between uPA and uPAR. These results are expected to be informative for developing new medicines blocking the binding of uPA and uPAR.     

The effect of a histidine-excess diet on cholesterol synthesis and degradation in rats

Feeding a diet high in excess histidine (5% L-histidine) resulted in hypercholesterolemia and enlargement of the liver in rats. To clarify the mechanism of the hypercho-lesterolemia cholesterol synthesis and degradation were followed. We found that hepatic 3-hydroxy-3-methylglutaryl-coenzyme A reductase activity in histidine-excess diet rats was significantly higher than in rats fed a basal diet. Incorporation of [³H]water into cholesterol of liver slices from rats fed the histidine-excess diet was higher than incorporation into liver slices from rats fed the basal diet (expressed per liver per 100 g body weight).In vivo incorporation of [³H]water into hepatic cholesterol was also higher, but the incorporation into cholesterol of the small intestine was lower in histidine-fed rats than in rats fed the basal diet (expressed per liver per 100 g body weight). Hepatic cholesterol 7α-hydroxylase activity was similar in both groups. The data suggest that the hypercholester-olemia caused by histidine-excess diet appears to be due to the stimulation of cholesterol synthesis in the liver.     

PHOTOCHEMICAL REACTION OF 6H-BENZO[cd]PYREN-6-ONE (NAPHTHANTHRONE)

Fluorescence of naphthanthrone,6H-benzo[cd]pyren-6-one, in degassed organic solution increases on light irradiation, but it stays almost constant in aerated solution. To clarify this phenomenon, the absorption and emission spectra of naphthanthrone were measured in several organic solvents as a function of irradiation time at room temperature and 77 K. The fluorescence enhancement was observed only in solvents containing hydrogen such as ethanol and benzene, but not observed in non-hydrogen-containing solvents. On the basis of the experimental data we proposed the mechanism of the fluorescence enhancement. Naphthanthrone excited to the triplet state on irradiation attracts a near solvent molecule around its carbonyl group to form an association species, which provides strong fluorescence near the wavelength region of the fluorescence of naphthanthrone. The absorption energy and absorptivity calculated for the compound by the ZINDO method were consistent with the experimental results.     

Effect of calcination atmosphere and temperature on γ-Al2O3 supported cobalt Fischer-Tropsch catalysts

The effect of calcination temperature and atmosphere on the properties of γ-Al₂O₃ supported cobalt Fischer-Tropsch catalysts has been investigated. One common precursor for all the catalysts was prepared by incipient wetness impregnation of γ-Al₂O₃ with an aqueous solution of cobalt nitrate hexahydrate. It was subjected to four different calcination atmospheres (air/50% steam: 30 mL/min, air: 30 mL/min, air: 50 mL/min, N₂: 30 mL/min) and eight different calcination temperatures (range: 473–723 K), making the total number of samples 32. Both the post calcination nitrogen content and the cobalt dispersion were measured. The results demonstrated that in order to maximise the cobalt dispersion, it is necessary to use low calcination temperatures and remove the precursor decomposition products (NO, NO₂, H₂O) efficiently. The Fischer-Tropsch synthesis performance of two catalysts calcined at the same temperature, but at different air flow rates was evaluated. No significant effect of the air flow rate was found on the turnover frequency or C₅₊ selectivity, but a high flow rate resulted in 30% higher activity per gram catalyst.     

Uptake of secondary autoxidation products of linoleic acid by the rat

Incorporation of secondary autoxidation products (SP) of linoleic acid into the rat body was investigated. Radioactive SP was administered orally to a group of 5 rats, and excretions of radioactive substances in feces, urine and respiration were measured and compared with excretions from rats fed linoleic acid and its hydroperoxides. The SP-fed group excreted 45% and the other groups about 10% of the administered radioactivity through feces. Urinary excretion accounted for 52% of activity ingested in the SP group and less than 30% in the other groups. The¹⁴CO₂ produced in each group was about 25% of the ingested activity. Incorporation of the radioactive substances of SP into tissues and organs was measured periodically after administration of a single dose. The radioactive substances accumulated in the liver between 12–24 hr after administration and accounted for 2.6% of the total amount given, the highest level of all tissues and organs. This accumulation led to an elevation of serum transaminase activities, an increase in hepatic lipid peroxide, as determined by thiobarbituric acid test, and a slight hypertrophy of liver (1.5-fold). Therefore, absorbed SP appeared to contribute to the deleterious condition of the liver.     

Correlation between kinetics and chemical bonding state of catalyst surface in catalyzed magnesium hydride

We reported on the hydrogen desorption properties, microstructure, kinetics, and chemical bonding state of catalyst surface for composites of MgH₂ and 1 mol% Nb₂O₅ ball-milled for 0.02 h, 0.2 h, 2 h, 20 h under 1 MPa H₂ atmosphere, as well as hand-mixed (HM) one. Hydrogen desorption properties were significantly improved by ball-milling with Nb₂O₅. Then, we estimated by Kissinger Method the activation energy (E_a) of hydrogen desorption reaction that decreased with the increase of ball-milling time. Especially, E_a of the sample ball-milled for 0.2 h was drastically decreased, compared with that of the sample ball-milled for 0.02 h. TEM observations revealed that the distribution of Nb₂O₅ in MgH₂ was gradually improved during ball-milling. On the other hand, we confirmed by XPS that in the sample ball-milled for 0.2 h, Nb₂O_5-x phase(s) existed at least on the surface. It can be suggested that these deoxidized Nb₂O_5-x phases eventually decrease E_a as substantial catalyst rather than Nb₂O₅ itself.