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Showing papers by "Tokyo University of Science published in 1987"


Journal ArticleDOI
TL;DR: The reactions of Irgasan DP 300 with chlorine in water were investigated by means of gas chromatography (GC) and GC-mass spectrometry to produce dichloro- and trich chloro-2-(2,4-dichlorophenoxy)phenols in chlorine-treated water, followed by the decomposition of these intermediates to chlorophenols.

46 citations



Journal ArticleDOI
TL;DR: Studies were undertaken to elucidate further the mechanism by which emodin was converted into a direct-acting mutagen to Salmonella typhimurium TA1537 by the hepatic microsomes and the reconstituted cytochrome P-450 system.
Abstract: Studies were undertaken to elucidate further the mechanism by which emodin, an anthraquinoid mycotoxin and constituent of rhubarb, was converted into a direct-acting mutagen to Salmonella typhimurium TA1537 by the hepatic microsomes and the reconstituted cytochrome P-450 system. Emodin was activated into a mutagenic principle(s) in the reconstituted cytochrome P-450 system, and its mutagenicity was significantly higher with the fraction II (P-448 type) than the fraction I (P-450 type) derived from the hepatic microsomes of PCB-induced rats. Thin-layer chromatographic analysis revealed that the purified cytochrome II-a (maximal CO-differential spectrum at 448.0 nm and high-spin form) activity converted emodin into 2-hydroxy-emodin, a direct-acting mutagen.

26 citations


Journal ArticleDOI
J. Kobayashi1, T. Horikoshi1, J.-C. Ryu1, F. Tashiro1, K. Ishii1, Y. Ueno1 
TL;DR: Gas-liquid chromatography was used to investigate the hepatic and intestinal metabolism of T-2 toxin, a cytotoxic and immunodepressive trichothecene produced by species of Fusarium, and showed that the rate of the hydroxylation reaction was highest in the liveratic microsomes of guinea-pigs, followed by mice.

25 citations



Journal ArticleDOI
TL;DR: Gas chromatographic analyses of n-hexane extracts demonstrated that chlorine treatment of river-water not only produces, in addition to THMs, new lower-molecular-weight and chromatographiable organic halogen compounds (COX), but also decomposes the original halogenated organics present.

14 citations



Journal ArticleDOI
TL;DR: In this article, superconductivity induced by proximity effect in narrow-gap high-electron-mobility semiconductor InAs and its surface inversion two-dimensional electron gas (2DEG) has been confirmed using Nb-InAs-Nb SNS junctions.
Abstract: Superconductivity induced by proximity effect in narrow-gap high-electron-mobility semiconductor InAs and its surface inversion two-dimensional electron gas(2DEG) has been confirmed using Nb-InAs-Nb SNS junctions. It is found that supercurrent through the junctions is strongly dependent on SN interface properties. Carrier concentration and electrode spacing dependences of critical current Ic are obtained. Coherence lengths in n-InAs and surface inversion layer are discussed on the basis of proximity theory. Supercurrent control is realized using three-terminal device operation in field-effect and quasiparticle-injection modes.

6 citations


Journal ArticleDOI
TL;DR: Water samples collected from the Chao Phraya, Bang Pakong and Tha-Chin rivers and the Upper Gulf of Thailand in the rainy season and dry season in 1983 and 1984 suggest a multiplicity of sources ranging from indigenous biological materials to petroleum activities.

6 citations



Journal ArticleDOI
TL;DR: In this article, a method and apparatus for forming preventive coatings by sputtering are described wherein metal atoms originate in a Penning discharge space and are then guided through a duct in order to reach a tooth and then to form a spot coating on the surface.
Abstract: Dental caries starts locally on a tooth surface; thus, the selective protection by metal films on pits and fissures is simple and effective. The method and apparatus for forming preventive coatings by sputtering are described wherein metal atoms originate in a Penning discharge space and are then guided through a duct in order to reach a tooth and then to form a spot coating on the surface. A compact-size sputtering apparatus for the coating of a gold film on a surface of extracted teeth or glass substrates has been designed and the film-deposition characteristics examined. The typical deposition rate is 1 nm/s for a 6-mm film on a glass substrate. After gold films are coated on extracted teeth, the teeth are immersed in an 0.1 mol lactic acid solution (pH=4.0). The obtained results indicate that a thickness of about 200 nm is necessary and satisfactory for protecting against dental caries in vitro.