4-carboxy-1,2-cyclohexanedionedioxime complexes of nickel(ii) in alkaline media

The reactions of 4-carboxy-1,2-cyclohexanedionedioxime and nickel(II) were studied in alkaline media. Spectrophotometric studies indicate the presence of a 1:1 complex ion, NiD^-. Magnetic susceptibility measurements on a series of solutions of varying ratios of vic-dioxime and nickel(II) showed that the 1:1 complex ion was diamagnetic and that two paramagnetic complexes, probably NiD₂^4- and NiD₃^7-, are present in solution. The stability constants for the three complexes were calculated from spectrophotometric and magnetic susceptibility data. The log K values were found to be log K₁ = 28.74 ± 0.60, log K₂ = 0.76 ± 0.15, and log K₃ = 3.67 ± 0.73, respectively.     

An improved kinetic determination for creatinine using the Abbott ABA-100

An improved method for the kinetic determination of creatinine on the Abbott ABA-100 is described. By simplex optimization of the picrate and hydroxide reaction concentration a 35% increase in reaction rate, with respect to the Abbott methodology, was obtained. The new method correlated more closely with the Technician AutoAnalyzer Method (N-30) than did the latter method. The percentage CV for the improved method for high and low quality control sera was 2.4 and 3.6%, respectively. The presence of protein in the standards was found to cause a decrease in the reaction rate with respect to aqueous standards.     

The bistable TPID/CHCl3 photoreaction: Numerical simulation and experimental results

Investigation of the photochromic system TPID/CHCl₃ (TPID = triphenylimidazolyl dimer) in a CSTR provided the first example of isothermal photochemical bistability. The reaction mechanism was established and the relevant kinetic and spectroscopic parameters were estimated experimentally. In order to predict the quantitative dynamic behavior of the TPID/CHCl₃ system these parameters were refined numerically using batch reactor data. The adjusted model simulates very accurately bistability either as a function of residence time τ, or as a function of incident photon flux I₀.     

A fast, simple colorimetric determination of total urinary estrogen

An improved method for the kinetic determination of creatinine on the Abbott ABA-100 is described. By simplex optimization of the picrate and hydroxide reaction concentration a 35% increase in reaction rate, with respect to the Abbott methodology, was obtained. The new method correlated more closely with the Technician AutoAnalyzer Method (N-30) than did the latter method. The percentage CV for the improved method for high and low quality control sera was 2.4 and 3.6%, respectively. The presence of protein in the standards was found to cause a decrease in the reaction rate with respect to aqueous standards.     

Use of dyes in solid medium for screening ligninolytic activity of selective actinomycetes

Applied Biochemistry and Biotechnology -     

High-resolution infrared spectrum of carbon suboxide: The ν4 + 2ν70 and ν4 + 3ν71 − ν71 bands

The infrared spectrum of the ν₄ + 2ν₇ progression of C₃O₂ has been recorded with a resolution of about 0.018 cm^?1. Two bands of the progression have been completely analyzed. The band centers obtained in this study establish, when combined with previously published experimental results, than 3ν₇¹ is 97.22 cm^?1 above the ground vibrational state.     

Reactions of azirines with N-bromosuccinimide

Reaction of 2-aryl azirines with N-bromosuccinimide in dioxane or carbon tetrachloride at ?23°, affords α,α'-dibromoketones, dibromoazines, bromopyrazines, 2,5-diarylpyrazines and 3,6-diarylpyrazines.     

[13C]Aminopyrine and [13C]Caffeine Breath Test: Influence of Gender,Cigarette Smoking and Oral Contraceptives Intake

Abstract

The [¹³C]aminopyrine breath test ([¹³C]ABT) measures the global activity of cytochrome P450 in vivo and is a sensitive indicator of liver metabolic dysfunction. The present study aims to determine whether gender and cigarette smoking influence the results of [¹³C]ABT as well as to confirm the effect of oral contraceptive steroids (OCS) intake on this metabolic test. Hundred and ten healthy subjects, including men and women, smoker and non-smoker, women taking OCS or not, were phenotyped for CYP1A2 using the [¹³C]caffeine breath test and underwent a [¹³C]ABT. Both tests showed large inter-individual variations in accordance with that of CYP450 liver content. [¹³C]ABT was sensitive enough to point out a significant induction or inhibition related to cigarette smoking habits or OCS. The combined effect of smoking and OCS resulted in an overall unchanged metabolic activity. Consequently, the impact of the studied conditions on the [¹³C]ABT parameters must be considered by clinicians or clinical investigators.