RADIOISOTOPES

Approximation Formulas on Buildup Factors as a Function of the Effective Atomic Number, Gamma-Ray Energy and Relaxation Length

Tatsuo HOSHI

1981 Volume 30 Issue 2 Pages 67-72
Published: February 15, 1981
Released on J-STAGE: September 07, 2010

DOIhttps://doi.org/10.3769/radioisotopes.30.2_67

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Approximation formulas on energy, dose and energy absorption buildup factors were constructed to facilitate the computation of the values in a material irradiated with a point isotropic gamma-ray source. The approximation formulas were expressed as a function of the effective atomic number (Z), gamma-ray energy (E) and relaxation length in mean free path (fur), with 15 or 17 coefficients.
The approximate values were compared with the buildup factors reported by Goldstein and Wilkins in the range of Z, E and fir adopted for gamma-ray irradiator design, that is in 7.42≤Z≤26, 0.5≤E (MeV) ≤4 and 0≤μγ≤10. It was shown that the maximum relative errors of the approximation formulas are ±5.20, ±4.3% and ±3.5% for energy, dose and energy absorption buildup factor, respectively.

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Development of Scintillators for α- and β-Rays

—Comparison of relative luminescence efficiencies of scintillation and photoluminescence of various phosphors—

Yasuro ATO, Soji MIYAGAWA

1981 Volume 30 Issue 2 Pages 73-79
Published: February 15, 1981
Released on J-STAGE: September 07, 2010

DOIhttps://doi.org/10.3769/radioisotopes.30.2_73

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Relative scientillation efficiencies of various phosphors such as ZnS, ZnCdS and Zn₂SiO₄ under excitation by a-rays from ²¹⁰Po, β-rays from ⁹⁰Sr-⁹⁰Y were compared with those excited by 365 nm (3650Å) UV light. The influence on the structure, mixture rate, firing atomosphere and firing temperature of phosphors on the efficiency were noted. The results were as follows:
(1) ZnS type phosphors generally showed the highest efficiencies under all types of excitation examined.
(2) Among ZnS: Cu type phosphors, the specimen fired at 1100°C was the most efficient under the three types of excitation.
(3) A highly efficient phosphor in photoluminescence was not always efficient in scintillation.
(4) The addition of a flux was generally effective for scintillation as for photoluminescence.
(5) The phosphors fired in H₂S showed a lower efficiency than those fired in air on N₂ in both scintillation and photoluminescence.

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Labeling Reactions of _L-Lysine and Poly-_L-Lysine with ⁵⁷Co and Their Distribution in Normal and Ehrlich Ascites Tumor-Bearing Mice

Noriko MOTOHASHI, Mineko TERAO, Itsuhiko MORI

1981 Volume 30 Issue 2 Pages 80-85
Published: February 15, 1981
Released on J-STAGE: September 07, 2010

DOIhttps://doi.org/10.3769/radioisotopes.30.2_80

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The labeling reactions of L-lysine and poly-L-lysine (average of molecular weight: 3400 (I), 15000 (II), 25000 (III) and 87000 (IV) ) with⁵⁷Co²⁺ions and the tumor and organ distributions of their complexes were examined. L-Lysine and poly-L-lysine with ⁵⁷Co²⁺ions were incubated for 20 hrs at 30°C in the solution of pH 9.0 and 50 v/v % ethanol solution of pH 10.5, respectively. L-Lysine and poly-L-lysine were labeled with ⁵⁷Co²⁺ions in the radiochemical yields of over 95 and 60-70%, respectively. The radioactive polypeptides were separated from unreacted ⁵⁷Co²⁺ions in the range of pH 8.0 to 8.5 by means of gel filtration on Sephadex G-25 M column (1.5×5.0 cm) .
The radioactive complexes were injected intavenously in mice. L-Lysine complex was excreted rapidly from tumor tissue and various organs. The localization of poly-L-lysine complexes in tumor was higher 3 to 5 times than that of L-lysine complex at 20 hrs after injection. The localization in tumor increased in the order of L-lysine-<II-<I-complex. II-Complex was excreted scarcely from tumor. ⁵⁷Co poly-L-lysine complexes revealed remarkably high localization in liver and spleen. The localization in tumor of those complexes seemed to be related to the molecular weight and the positive charge of lysine.

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Syntheses of Deuterated 3'-Hydroxymethyl-4- (dimethylamino) -azobenzene and Related Compound

Yukio MORI, Toshiro NIWA, Kazumi TOYOSHI

1981 Volume 30 Issue 2 Pages 86-91
Published: February 15, 1981
Released on J-STAGE: September 07, 2010

DOIhttps://doi.org/10.3769/radioisotopes.30.2_86

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3'-Hydroxymethyl-4- (dimethylamino) azobenzene (I), a new potent hepatocarcinogen, and 3, 3'-bis (hydroxymethyl) azobenzene (II) were labeled with multiple-deuterium for the purpose of investigating their metabolisms by the ion cluster technique. I-d₄ was obtained in a 22% yield from benzoic-d₅ acid (99 atom% D) by nitration, catalytic hydrogenation, reduction, and coupling of the diazonium salt with N, N-dimethylaniline and its deuterium content was 99 atom%. On the other hand, II-d₈ was obtained in a 7% yield from 3-nitrobenzoic-d₄ acid by reduction and was 91 atom% D.

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Measurement of Regional Cerebral Blood Flow by ¹³³Xe Inhalation Method

—Experimental system and its evaluation of data analysis by simulation study—

Yuko MIURA, Iwao KANNO, Shuichi MIURA, Takenori HACHIYA, Eiichi HAGAMI ...

1981 Volume 30 Issue 2 Pages 92-98
Published: February 15, 1981
Released on J-STAGE: September 07, 2010

DOIhttps://doi.org/10.3769/radioisotopes.30.2_92

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Noninvasive measurement of regional cerebral blood flow (rCBF) by ¹³³Xe inhalation and simulation studies of the errors in analyzing ¹³³Xe clearance curves were reported. Our system was based on Obrist's 10 minutes desaturation method after 1 minute inhalation of 185-222 MBq (5-6 mCi) /l of ¹³³Xe gas mixed in the air. Clearance curves were simultaneously measured at six location in each hemisphere. End-tidal ¹³³Xe curve used for correction of recirculation was generated from respired air curve. Values for rCBF were calculated by two compartment analysis of the head curves.
We evaluated the experimental errors with computer simulation studies. The synthetic head curves were generated with a three compartmental model representing the fast and slow component in the brain and the extracerebral component. The arterial input function used was the end-tidal curves of a typical control subject. The results of computer simulation studies were obtained as follows: F₁ that is the flow of the fast compartment in brain and adequate reliability; statistical errors for normal value of F₁ (80ml/100 g/min) were 5% at 30 kcpm; the optimum end point of curve-fitting was 10-11 minutes after 1 minute inhalation of ¹³³Xe gas; the error due to remaining activities of repreceding study was 3% at the interval of 25 minutes between inhalation.

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Clinical Significance of RCT in Liver Diseases

Junichi NISHIKAWA, Kikuo MACHIDA, Jun ISHIMARU, Akira TASAKA

1981 Volume 30 Issue 2 Pages 99-103
Published: February 15, 1981
Released on J-STAGE: September 07, 2010

DOIhttps://doi.org/10.3769/radioisotopes.30.2_99

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Radionuclide Computed Tomography (RCT) was performed in 40 cases with various liver diseases. Indication of RCT was determined by the fact that usual liver scintigrams showed or suspected space-occupying lesion. In diffuse hepatocellular disease, RCT added diagnostic informations in 10 out of 17 cases. In these patients, RCT referred decreased uptake area to morphological change such as prominent porta hepatis, widening of both lobes or lateral seg. and medial seg. of the left lobe, and so on. In cases with liver tumor, RCT demonstrated the liver by axial plane, so one could easily or precisely diagnose the location of the mass. RCT performance requires only 30 min. additionally, and no additional injection. We conclude RCT should be performed to the patients whose liver scintigrams show or suspect space-occupying lesion.

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Fallout ²³⁹Pu, ²⁴⁰Pu and ⁹⁰Sr in Surface-air in Ibaraki-prefecture, Japan

Aiji YAMATO

1981 Volume 30 Issue 2 Pages 104-108
Published: February 15, 1981
Released on J-STAGE: September 07, 2010

DOIhttps://doi.org/10.3769/radioisotopes.30.2_104

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Measurements of ^{239, 240}pu and ⁹⁰Sr were performed on air-dust samples collected by means of filtration with cellulose-asbestos filter at Ibaraki prefecture, Japan during 1974 to 1979. The ranges of ^{239, 240}Pu and ⁹⁰Sr content determined in these samples are 0.041-1.9μBq/m³-air (1.1-52 aCi/m³) and 2.3-87 μBq/m³-air (0.062-2.3 fCi/m³) respectively. The activity ratios of ^{239, 240}Pu/⁹⁰Sr are found to be in a range between 0.008 to 0.026 with a mean value of 0.017.
General trend on time variation of the content of ^{239, 240}Pu and ⁹⁰Sr in the surface air was in similar pattern each other. The content of these nuclides increased after the Chinese nuclear test explosions, and also in spring seasons with the exception of a few cases.

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Measurement of Radon in Air by α Track Method

—Enhancement of detection sensitivity using lamp—

Yasuyuki MAKI, Fujio TANAKA

1981 Volume 30 Issue 2 Pages 109-111
Published: February 15, 1981
Released on J-STAGE: July 21, 2010

DOIhttps://doi.org/10.3769/radioisotopes.30.2_109

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Possibility of Thermoluminescence Dating of Pottery and Porcelain

Yasuro ATO, Hideharu MATSUDA, Tatsuro KAWASHIMA, Soji MIYAGAWA, Ryoiti ...

1981 Volume 30 Issue 2 Pages 112-114
Published: February 15, 1981
Released on J-STAGE: July 21, 2010

DOIhttps://doi.org/10.3769/radioisotopes.30.2_112

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Electronics Design for Hybrid Emission Computed Tomography “HEADTOME”

Shuichi MIURA, Iwao KANNO, Yuko MIURA, Kazuo UEMURA

1981 Volume 30 Issue 2 Pages 115-118
Published: February 15, 1981
Released on J-STAGE: July 21, 2010

DOIhttps://doi.org/10.3769/radioisotopes.30.2_115

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Fundamental Study of Tetra bead-125 Kit

Setsuko SATO, Shigeko KURIHARA, Sachiko KOIKE, Kiyoko KUSAKABE, Hirosh ...

1981 Volume 30 Issue 2 Pages 119-121
Published: February 15, 1981
Released on J-STAGE: July 21, 2010

DOIhttps://doi.org/10.3769/radioisotopes.30.2_119

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A Fundamental and Clinical Evaluation of RIA-gnost TSH Kit (Bottle Type)

Tetsuya KAMEI, Toshie YAMAZAKI, Ikuro TATSUNO

1981 Volume 30 Issue 2 Pages 122-124
Published: February 15, 1981
Released on J-STAGE: July 21, 2010

DOIhttps://doi.org/10.3769/radioisotopes.30.2_122

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Radioisotopes Usage in the Studies on Biosynthesis of Plant Reserves at the Ripening Stage

Kunisuke TANAKA, Zenzaburo KASAI

1981 Volume 30 Issue 2 Pages 125-134
Published: February 15, 1981
Released on J-STAGE: July 21, 2010

DOIhttps://doi.org/10.3769/radioisotopes.30.2_125

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[title in Japanese]

1981 Volume 30 Issue 2 Pages A2097-A164
Published: February 15, 1981
Released on J-STAGE: July 21, 2010

DOIhttps://doi.org/10.3769/radioisotopes.30.2_A2097

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