In order to measure accurately the ultrasonic speeds in liquids under pressure, a new experimental apparatus was constructed employing a sing-around method. The ultrasonic speeds in benzene and ...toluene were measured at temperatures of 293.15, 298.15 and 303.15K, and pressures up to 160MPa. By measuring the pressure variations of ultrasonic speeds in benzene, the reliability of apparatus was confirmed to be better than ±3msec-1. From the experimental results of the pressure dependence of ultrasonic speeds, the densities under high pressure were calculated. The calculation method was improved in part from that published previously. The densities thus obtained agreed well with the experimental values reported in the literature within approximately 0.2 per cent over the range of pressure up to 160MPa, and the improved calculation method of density was found to be good, especially in higher pressure region.
By pico- and nanosecond spectroscopy methods, the transient absorption spectra and lifetimes of the triplet states of 2,4,6-triisopropylbenzophenones, the 1,4-biradicals and the dienols were ...measured. The decays of the T′←T1 absorptions were accompanied by the rate matching increase in the absorptions -of the biradicals.
The effect of various proteases (trypsin, chymotrypsin, subtilisin, protease 401, and thermolysin) on the mitochondrial isoenzyme (m-AST) and cytoplasmic isoenzyme (c-AST) of human and swine ...aspartate aminotransferase (AST;EC 2.6.1.1) was evaluated. All procedures including the reaction with proteases and the subsequent determination of the AST activity were carried out in an automatic analyzer. The mammalian c-AST was efficiently inactivated by chymotrypsin, subtilisin and protease 401 while m-AST activity decreased very slowly with these proteases. Thermolysin and trypsin showed much less effect on c-AST activity. Especially, chymotrypsin at concentrations of 0.5-1.0 g/L inactivated human c-AST almost completely but showed no detectable inactivating effect on m-AST. Thus chymotrypsin appears to be the most suitable protease for the differential determination of AST isoenzymes in human serum. Further studies on the effects of proteases with AST from other species showed that Escherichia coli AST resembled mammalian m-AST while Pseudomonas AST resembled c-AST.
The transient absorption spectra of the title compounds in solutions at room temperature have been measured on the picosecond time scale. For 9‐acetylanthracene and acridine there were measurable ...changes of the spectral shapes in the first picosecond region, while no spectral change was observed for benzophenone.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
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