All issues
Volume 58, Issue 4
Displaying 1-3 of 3 articles from this issue
- |<
- <
- 1
- >
- >|
Article
-
Akira YOSHIDA, Hiroshi IMAIZUMI, Takayuki SATO, Naoki KANO2009 Volume 58 Issue 4 Pages 121-128
Published: 2009
Released on J-STAGE: April 28, 2009
JOURNAL OPEN ACCESSTo quantitatively evaluate the influence of tritium (3H or T) on ecosystem, the hydrogen isotope exchange reaction (T-for-H exchange reaction) between each aromatic amino acid (L-tyrosine, L-phenylalanine, or L-2-phenylglycine) and HTO vapor was observed at 50-70°C in the gas-solid system. Applying the A"-McKay plot method to data (obtained in the exchange reaction), the rate constants (k) of functional groups of each aromatic amino acid in this reaction was obtained. Comparing the rate constants, following six matters have been found in the T-for-H exchange reaction. (1) The reactivity of the functional groups in each amino acid increases with increasing temperature. (2) The reactivity of the functional groups of the amino acids (used) increases in the order of L-tyrosine, L-phenylalanine, and L-2-phenylglycine. (3) As to L-tyrosine, (i) the temperature dependence of each functional group increases in the order of COOH group, OH one, and NH2 one, (ii) the reactivity of OH group is 3.8 times greater than that of NH2 one, and (iii) the reactivity of COOH group is 2.0 times greater than NH2 one. (4) As to the influence of the substituent, the reactivity of NH2 group is larger than that of the COOH one. (5) Using the A"-McKay plot method, the reactivity of each functional group in an amino acid can be nondestructively and simultaneously clarified without using masking reagent. (6) The results obtained in this work is useful for preventing T contamination and for evaluating the influence of T on environment.View full abstractDownload PDF (1018K)
Review Article
-
Jun SATO, Yuichi KURIHARA, Masaomi TAKAHASHI2009 Volume 58 Issue 4 Pages 129-143
Published: 2009
Released on J-STAGE: April 28, 2009
JOURNAL OPEN ACCESSRadioactive disequilibria among U-series nuclides are observed in the magmas from volcanoes in the world. Basaltic products from Izu arc volcanoes, including Izu-Oshima and Fuji volcanoes, show 230Th<238U and 226Ra>230Th disequilibria, indicating that the addition of U- and Ra-rich fluid from the subducting slab to the mantle wedge at the magma genesis. The disequilibria of 226Ra>230Th in the erupting magmas suggest that the timescale from magma genesis to the eruption may be less than 8000years.View full abstractDownload PDF (3198K)
Lecture
Serial Review on Clinical PET Tracers
-
Nagara TAMAKI, Keiichiro YOSHINAGA, Chietsugu KATOH2009 Volume 58 Issue 4 Pages 145-151
Published: 2009
Released on J-STAGE: April 28, 2009
JOURNAL OPEN ACCESSPET myocardial perfusion agents include 15O-water, 13N-ammonia, and 82Rb. 15O-water has an advantage for best quantification of myocardial blood flow, whereas 13N-ammonia is suitable for providing high quality myocardial perfusion images with quantitative assessment. On the other hand, since 82Rb is a generator produced perfusion tracer, it has a potential for wide use of PET perfusion study without use of cyclotron. 82Rb PET perfusion study is commonly performed in USA, and will be available in Japan in the near future.View full abstractDownload PDF (2160K)
- |<
- <
- 1
- >
- >|