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S Ohmori

Publications and source records attributed to S Ohmori.

At least 289 records · Page 16Linked to original sources
PubMed1979

[Neutron activation analysis of trace elements in sea water samples (author's transl)].

Analytical values of trace elements in sea water samples have been fluctuated according to the sampling locations, the analytical procedures and so on. It is very important in marine chemistry to elucidate the cause of such concentration variations. This report is the analytical results of the samples obtained in the Pacific Ocean, the Indian Ocean and the Sea of Japan, by means of neutron activation analysis. As the preconcentration, APDC-chelate extraction and freeze-drying were adopted. The specimens obtained by this extraction from 500 or 800 ml samples were irradiated by KUR reactor for 1 min, 1 hr to 10 hrs and the gamma-ray spectrometry with a Ge(Li) detector was used for the determination of V, Mn, Cu, Zn, U, Fe, Co, Ni, Ag, Sb and Au. By about 80 hrs irradiation of the specimens obtained by freeze-drying from 20 ml samples and their gamma-ray spectrometry, Sc, Cr, Fe, Co, Zn, Rb, Sr, Ag, Sb and Cs were determined. The former procedure gives concentrations of elements in species reactable with APDC, but the latter method shows entire concentrations of the elements in the sea water samples. Some considerations on the analytical values and the comparisons of the both methods are described.

Activation Analysis↗
PubMed1976

Effects of glutamic acid relatives on the electrical activity of an identified molluscan giant neurone (Achatina fulica Férussac).

Effects of glutamic acid and its relatives were examined on the electrical activity of two kinds of neurones (the PON, periodically oscillating neurone, and the TAN, tonically autoactive neurone) identified in the suboesophageal ganglia of an African giant snail, Achatina fulica Férussac. L- and D-Glu, L-Asp, Gly and beta-Ala did not show any effect on the two neurones. However, beta-hydroxyglutamic acid (BHGA) showed a remarkable inhibitory effect on the PON. Erythro-L-BHGA had the strongest effect of these stereoisomers, and the critical concentration of this substance to produce the effect was 10(-6)-3 X 10(-5) g/ml (6-18 muM) when administered in the bath application. We confirmed by the microdrop application that erythro-L-BHGA directly hyperpolarized the PON neuromembrane. When the curve of current-voltage relationships (I-V curve) of the PON neuromembrane measured under erythro-L-BHGA at 10(-5) g/ml (61 muM) was superimposed on the curve of the normal state using the firing level as the common standard, these two curves showed concordance in a wide range of membrane polarization level. This concordance implies that the membrane resistance was maintained normally under erythro-L-BHGA at this concentration. A higher concentration of 10(-4) g/ml (0.61 mM) of this substance caused a decrease of PON membrane resistance and a remarkable elevation of its firing level. The TAN was not sensitive to BHGA, but sensitive to GABA and its derivatives.

Amino Acids↗
PubMed1975

Inhibitory effect of beta-hydroxyglutamic acid on a molluscan giant neurone.

We found a spontaneously firing neurone, inhibited by beta-hydroxy(erythro)-L-glutamic acid, identified in the subesophageal ganglia of an African giant snail (Achatina fulica Férussac), although this neurone is not sensitive to L-glutamic acid. We suggest that beta-hydroxy(erythro)-L-glutamic acid may be a putative inhibitory synaptic transmitter of the identified molluscan neurone.

Animals↗
PubMed1975

Biosynthesis of homocysteine sulfinic acid in the vitamin B6-deficient rat.

The formation of L-homocysteine sulfinic acid in the rat was examined in vivo and in vitro. This compound was rarely found, in trace amounts, in the urine and could not be detected in the tissues of various animal species studied. When L-homocysteine or methionine was given orally or intraperitoneally to rats deficient in vitamine B6, the level of homocysteine sulfinic acid in the urine increased and its synthesis could be detected in the liver.

Animals↗