Hydrogen production by conversion of methane over nickel-supported USY-type zeolite catalysts

Hydrogen production by conversion of methane over Ni-supported zeolite catalysts was investigated, and Ni-supported USY-type zeolite (Si/Al₂ = 14.0, 360) was found to have longer catalytic lifetime than Ni-supported silica (Cab-O-Sil) catalyst, which had been reported to have the longest catalytic lifetime for this reaction.     

Quality control of radioimmunoassay by bivariate analysis

Automatic calculation of control charts for precision and accuracy of radioimmunoassay was reported by Faure, et al. Duplicate control samples independently measured was assumed to have a bivariate normal distribution. In this case they assumed that the correlation coefficient between each value of the pairs of control samples is zero. Our experience using this method revealed that a considerable number of assayed samples distributed outside the calculated control limits in case of "accuracy control". It was considered that this happened because in radioimmunoassay the between-assays precision is usually larger than the within-an-assay precision and there is a significant correlation between values of duplicates. We also found equal probability density did not make a true circle but a long circle. Therefore in the present paper we proposed for control charts of radioimmunoassay an equal probability long circle calculated by bivariate analysis of Mahalanobis' generalized distance. It was found that a Mahalanobis' long circle could explain the density distribution of radioimmunoassay with a reasonable percent of samples outside the calculated control limits. What happened here can be interpreted by a large between-assays variability shown by some commercial kits. This automatic calculation method could be applied not only for quality control but also for evaluation and comparison of radioimmunoassay system or commercial kits. Control survey could also be analyzed by such a method.     

Renal blood volume vs. glomerular filtration rate: evaluation with C15O and 88Ga-ethylenediaminetetraacetic acid (EDTA) study

68Ga-EDTA (ethylenediaminetetraacetic acid) is simply and economically obtained without a cyclotron. We used renal blood volume (RBV) values obtained by C15O studies for blood activity subtraction on renal time activity curves using a positron emission tomography for the determination of the glomerular filtration rate (GFR) by intravenous 68Ga-EDTA administration. Positive correlation was revealed between the GFR and RBV values, where the ratio of blood activity in whole renal activity increased relatively as GFR value decreased. The estimation using a correction equation derived from the correlation curve was possible without a C15O study.     

OBSERVATION OF PHASE TRANSITIONS IN INTACT LEAVES BY INTRINSIC LOW-LEVEL CHEMILUMINESCENCE

The Arrhenius plots of a remnant intrinsic ultraweak light emission from dark-adapted leaves of hibiscus, bean, cucumber, tomato and spinach exhibit strong linear behavior, despite the structural heterogeneity of the intact leaf. Well-defined break points within the temperature range from 8°C to 17°C could be found in these plant species. In the case of hibiscus and cucumber an additional feature of a thermotropic phase change around 20°C and 24°C, respectively, could be detected. However, in the case of spinach, a representative of a chilling resistant plant species, the changes in activation energies obtained were only minor. Isolated chloroplasts of spinach leaves did not show identical thermal behavior of luminescence in comparison with the intact leaf. The activation energies were significantly lower and the transition features were different compared to intact leaves. A possible relationship between the thermal behavior of low-level chemiluminescence and the chilling sensitivity of plants is suggested.     

Determination of the major urinary metabolite of diphenylhydantoin by high-performance liquid chromatography

A method is described for the determination of 5-(p-hydroxyphenyl)-5-phenylhydantoin (p-HPPH), a major urinary metabolite of 5,5-diphenylhydantoin (DPH) in man. The assay involves acid hydrolysis, extraction and high-performance liquid chromatographic analysis using a column comprised of small-particle silica gel. This procedure has been used to determine p-HPPH levels in urine from healthy volunteers who ingested 400 mg of sodium DPH. The p-HPPH concentration was found to range from 10 to 300 μg/ml. The minimum detectable concentration of urinary p-HPPH was 1 μg/ml.     

Transfer of 137Cs and stable Cs in soil-grass-milk pathway in Aomori, Japan

The soil-to-grass transfer factors and grass-to-milk transfer coefficients were determined for ¹³⁷Cs and stable Cs in soil, grass and milk samples collected in Aomori Prefecture, Japan. The concentrations of ¹³⁷Cs in the soil and grass samples collected from 25 sampling sites were 13±12 Bq.kg^-1 and 2.0±2.1 Bq.kg^-1 dry wt., respectively. The geometric mean of soil-to-grass transfer factor of ¹³⁷Cs was 0.13 and its 95% confidence interval was 0.017-0.98. The transfer factor of ¹³⁷Cs was higher than that of stable Cs, and they had a positive correlation. The concentration of K in the soil affected both transfer factors. The concentration of ¹³⁷Cs in milk samples collected from 16 sites was 76±43 mBq.kg^-1 fresh wt. and had a good correlation with that of stable Cs. The geometric mean of grass-to-milk transfer coefficient of ¹³⁷Cs was 0.0027, assuming that a cow's total daily intake was 20 kg of dry grass. The transfer coefficient of ¹³⁷Cs was positively correlated with that of stable Cs.     

Heat capacity measurement of cubic lithium tungsten bronzes from 200 to 800°K

Heat capacities of three cubic lithium tungsten bronze samples (Li_xWO₃) with x values of 0.363, 0.437, and 0.478 were measured from 200 to 800°K. Heat capacities per gram-atom at the same temperature of Li_0.363WO₃ and Li_0.437WO₃ were equal within experimental error and also equal to those of Na_0.485WO₃, Na_0.698WO₃, and Na_0.794WO₃, regardless of the difference of the composition. λ-type heat capacity anomalies were observed around 330, 460, and 590°K in Li_0.363WO₃ and around 330 and 460°K in Li_0.437WO₃ and Li_0.478WO₃, showing the existence of second-order phase transitions. The entropy increments of the transitions were obtained as 1.36, 0.45, and 1.68 J mole^?1 K^?1 for Li_0.363WO₃, 1.09 and 0.59 J mole^?1 K^?1 for Li_0.437WO₃, and 1.42 and 0.50 J mole^?1 K^?1 for Li_0.478WO₃.