Observation of CO(2) in Fourier transform infrared spectral measurements of living Acholeplasma laidlawii cells

In monitoring the time course of conformational disorder by Fourier transform infrared spectroscopy for intact Acholeplasma laidlawii cells grown at 37 degrees C on binary fatty acid mixtures containing oleic acid and for cells grown on pure palmitic acid, an absorption band at 2343 cm(-1) was observed. The band intensity was found to increase with time. This band was not observed in the spectra for isolated membranes. It is suggested that the 2343 cm(-1) band is due to CO(2) dissolved in water, most likely produced at the final point of fermentation of amino acid by this microorganism.     

Fundamental study of the influence of pixel size on the quality of scintigrams

The effect of pixel size on image quality was investigated. The image quality was examined by abnormality detection and image preference for clinical images displayed with different pixel sizes. Smaller pixel size was found to be superior to large one in image quality using large field of gamma camera (FWHM 6.42 mm), 1.6mm pixel size (a 256 x 256 matrix) was found to be the best in image quality. Examined image minification effect, 3.2 mm pixel size (image size: 5 cm phi) was found to be superior to 1.6 mm pixel size (image size: 10 cm phi) in image preference and to be almost equal to 1.6 pixel size in abnormality detection.     

Thermal decomposition of acrylamide from polyacrylamide

Ion-attachment mass spectrometry with a temperature-programed direct probe allows the detection of intact pyrolysis products. It, therefore, offers the opportunity to monitor directly thermal byproducts on a real-time basis and potentially to detect thermally unstable products. With this technique, we investigated the thermal decomposition of polyacrylamide (PAA). Pyrolysis of PAA at around 450?°C produces many products (e.g., amides, imides, nitriles, ketones, aldehydes, and acrylamide oligomers). Acrylamide, which is a possible carcinogen, is produced abundantly in various industries, and, therefore, continues to be a cause for concern. We also investigated the kinetics of the thermal decomposition of PAA, and observed that the degradation of acrylamide obeys Arrhenius kinetics, which allowed us to correlate the rate constant with the absolute temperature and the activation energy. The activation energy of thermal decomposition was calculated from selected ion-monitoring curves of acrylamide.     

Reaction of acylsilanes with α-sulfinyl carbanions: regioselective synthesis of silyl enol ethers

The reaction of acylsilanes with α-sulfinyl carbanions such as α-lithioalkyl sulfoxide is described. The reaction proceeds to give silyl enol ethers preferentially through the initial formation of the α-silyl alkoxide intermediates. In particular, the products derived from enolizable acylsilanes were the regio-defined silyl enol ethers that cannot be obtained by usual enolization of the corresponding unsymmetrical ketones with base.     

Double Naphthalene‐Tagged Cyclodextrin‐Peptide Capable of Exhibiting Guest‐Induced Naphthalene Excimer Fluorescence

A cyclodextrin‐peptide hybrid (17NNβ) bearing two naphthalene units in the peptide side chain has been designed and synthesized as a novel chemosensor molecule. Circular dichroism study of the compound revealed that the peptide has α‐helix structure with a helix content of 41%. The peptide revealed both monomer and excimer emission and the intensity of the excimer emission increased while that of the monomer emission decreased upon addition of the guest compound. This behavior was observed for various guest molecules, suggesting that the system can be used for detecting molecules in aqueous solution.