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  • Author or Editor: H Kataoka x
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Abstract  

Boron and carbon on the surface of silicon wafers in ordinary atmospheres were measured by activation with the10B(d,n)11C and12Cd(d,n)13N reaction, respectively. Two sample plates in intimate contact were bombarded by deuterons, and the11C or13N formed at the inside surfaces were measured after chemical separation. From 1.2·1013 to 8.4·1013 atoms/cm2 of boron and from 2.4·1014 to 6.1·1015 atoms/cm2 of carbon were found ,and the sensitivity was extended down to 5·1012 and 3·1012 atoms/cm2 for boron and carbon, respectively.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: E. Yunoki, T. Kataoka, K. Michihiro, H. Sugiyama, M. Shimizu and T. Mori

Abstract  

The distribution of226Ra and238U in various soils has been studied. Supposing that radioactive equilibrium were in existence, the average activities of226Ra and238U would show a nearly 11 correlation. As weathering affects radioactive equilibrium in surface soil, radioactive equilibrium was not in existence. Therefore, four kinds of soil were selected from different weathering conditions, viz. river bed soil, paddy field soil, field soil and uncropped soil. The226Ra/238U ratio of various soils lies in the range of 1.63 to 2.41. The activity concentrations of226Ra were greater than238U in various soils. The ratio226Ra/238U can be shown to be a quantitative index of weathering. Phosphatic manure contains238U and its daughter isotopes in concentrations far exceeding the average abundance in the earth's crust. But the cultivated soils (paddy field soil, field soil) are not affected by fertilizers in Kamisaibara.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: E. Yunoki, T. Kataoka, K. Michihiro, H. Sugiyama, M. Shimizu and T. Mori

Abstract  

The238U and226Ra contents of small-volume aerosols are determined by a chemical analysis technique. Mean activity concentrations of238U and226Ra in aerosols over approximately ten years are 0.29·10–5 and 0.93·10–5 Bq/m3, respectively. The yearly variation of238U and226Ra in aerosols is small. The concentrations of226Ra are always larger than those of238U in the same sampling time. The correlation of238U and226Ra cannot be recogonized (r=0.18). The concentrations of summer samples are greater than those of winter samples for238U. One of the causes of seasonal difference may be due to the fact that the components of aerosols are different according to soil size, soil components, weathering states, etc.

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Abstract  

Distributions of238U and226Ra in agricultural samples and cultivated soils have been studied over ten years. The crops are rice, spinach and Chinese cabbage. Two investigated areas have been selected (35° 18 N, 113° 35 E). The agricultural samples and soils were collected annually from May 1982 through October 1991. The activity concentrations of226Ra in agricultural samples are greater than those of238U. The transfer factors of238U,226Ra are from 0.06·10–3 to 1.2·10–3. The226Ra/238U ratios for three agricultural samples have their characteristic values.

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This study examined the aging effect on disuse muscle atrophy prevention using heat stress. Wistar rats aged 7 and 60 weeks were divided into three groups as follows: control, immobilized (Im), and immobilized and heat stressed (ImH). Heat stress was given by immersing the hindlimbs in hot water (42 °C) for 60 min, once in every 3 days and the gastrocnemius (GAS) and soleus (SOL) muscles were extracted after 14 days. Muscle-fiber types were classified using ATPase staining. Heat shock protein 70 (HSP70) was assessed through Western blotting. In GAS muscle of both groups and SOL muscle of 7-week-old rats, the fiber diameter of each muscle type in the ImH group significantly increased compared with that in the Im group. However, this could not be observed in the SOL muscle of the 60-week-old rats. The increased percentage of type-I fibers and variability of types I and II muscle-fiber diameter were evident in the SOL muscle of the 60-week rats. HSP70 was significantly elevated in the ImH group compared with in the Im group in both muscle types of both age groups. Thus, effectiveness of heat stress in the prevention of disuse muscle atrophy appears unsatisfactory in aging muscle fibers.

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