[en] The 'impregnation-reduction method' has been investigated as a tool for the preparation of a direct methanol fuel cell (DMFC) anode. In this method, PtRu electrocatalysts were directly bonded onto a polymer electrolyte membrane by the chemical reduction of a mixture of Pt and Ru complexes impregnated in the membrane. The deposited PtRu particles were embedded in the 3-4 μm region of the membrane surface to form a porous and hydrophilic layer. The PtRu layers turned out to be applicable to the DMFC anode, despite their small active surface areas compared to PtRu nanoparticles used in the conventional method. Approximately, 3 mg cm^-2 of the PtRu layer exhibited better catalyst utilization and facilitated the release of evolving CO₂. This preparation technique is attractive for the application of various solid polymer electrolyte materials with low heat-resistance or various shapes, etc

[en] Skin tissues were collected from 8 A-bomb survivors and 4 non-exposed controls. Chromosome analysis among the non-exposed persons revealed normal karyotypes in all sites, including one cicatricial site. Structural chromosome aberrations were observed in 5 exposed persons (19 %, 76 %, 10 %, 5 %, and 2 %, respectively, of analyzable cells), all of whom had presented with acute symptoms after the bombing. In two survivors exposed at 1,250 m and at 1,390 m from ground zero, abnormal clones were detected in the cells from cicatricial site tissues, and in those from normal site tissues as well in one of them. An analysis for phytohemagglutin-stimulated peripheral lymphocytes performed in these survivors revealed chromosome aberrations in 19 % and 12 %, respectively. (Namekawa, K.)

[en] To clarify the effect of atomic bomb exposure on the skin, a cytogenetic study of cultured cells of the skin was performed. In non-exposed controls, only a few chromosomal aberrations were found. On the other hand, in A-bomb survivors, chromosomal aberrations such as translocation, deletion and inversion, which seem to have occurred at A-bomb exposure, were obseved. The percentage of cells with chromosomal aberrations was high among A-bomb survivors proximally exposed. In some of these A-bomb survivors, a clonal formation of cells with the same abnormal karyotype was observed. The above facts may indicate that considerable DNA damage of skin cells could have been induced by A-bomb exposure and that some of these cells formed clones thereafter. Based on these findings, it is deemed necessary to carry out a skin cancer survey on all A-bomb survivors. (author)

[en] Of 20,348 persons included in the extended Life Span Study in Nagasaki, 59 persons were registered as having skin tumors during the years 1955 - 1984. Included in this study were 40 patients with histologically proven skin cancer. Thirty five patients were considered to be exposed to ≥ one cGy. There was statistically significant correlation between the incidence of skin cancer and exposure doses in both men and women (p < 0.01). Overall, the incidence of skin cancer was significantly correlated as well with the distance from the hypocenter; however, this was not significant when restricted to either men or women. Because the incidence of skin cancer has definitively increased since 1955 among A-bomb survivors, follow-up of A-bomb survivors is warranted with respect to atomic bomb-related skin cancer. (Namekawa, K.)

[en] We previously reported that there was a high correlation between the exposure dose and the incidence of skin cancer in A-bomb survivors using the data of the Nagasaki Life Span Study of Radiation Effects Research Foundation and Nagasaki Tumor Registry. In Report 3 of this series, we clarified that the correlation between the exposure distance and the incidence of skin cancer was statistically significant in 140 cases of skin cancer collected from 31 hospitals in Nagasaki City and adjacent districts on the basis of the data of the total 66,276 A-bomb survivors recorded in the Scientific Data Center of Atomic Bomb Disaster, Nagasaki University School of Medicine, and that the correlation was the same even when the cases were divided by sex. In this report, we examined the chronological change of the incidence of skin cancer in Nagasaki A-bomb survivors, using the data of the Scientific Data Center of Atomic Bomb Disaster. It is likely that the incidence of skin cancer in Nagasaki A-bomb survivors has increased after 1962, especially after 1975 in those exposed within 2.5km from the hypocenter compared to those exposed at 3.0km or more. (author)

[en] In Report 1 of this series, we described that, in the cultured cells of skin tissues, chromosomal aberrations seemingly induced by A-bomb exposure were observed in Nagasaki A-bomb survivors, especially in those proximally exposed, and some of these cells with chromosomal aberrations formed clones. Based on these findings, we suspected that the incidence of skin cancer in A-bomb survivors might have increased. In this study, we tried to clarify the incidence of skin cancer among Nagasaki A-bomb survivors using the data of a total of 66,276 A-bomb survivors recorded at the Scientific Data Center of the Atomic Bomb Disaster, Nagasaki University School of Medicine. One hundred and ten cases of skin cancer were collected from the three major hospitals in Nagasaki City and were statistically analyzed in respect to the estimated distance from the hypocenter. The results were as follows: A high correlation was observed between the incidence of skin cancer and exposure distance in the analysis of all 110 cases and of the 50 male cases (p<0.01). However, no such correlation was observed in a separate analysis of the 60 female cases. (author)

[en] We already reported that there was a high correlation between the exposure dose and the incidence of skin cancer in A-bomb survivors using the data of the Nagasaki Life Span Study of Radiation Effects Research Foundation and Nagasaki Tumor Registry. In Report 3 of this series, we confirmed that the correlation between the exposure distance and the incidence of skin cancer was statistically significant. In Report 4, we clarified that the incidence of skin cancer in proximally exposed Nagasaki A-bomb survivors when compared to distally exposed victims appears to be increasing since 1975. In this final report of the series, we examined the characteristics of skin cancer in Nagasaki A-bomb survivors using 140 skin cancer cases collected from 31 hospitals in Nagasaki City and adjacent districts on the basis of the data of a total of 66,276 A-bomb survivors recorded in the Scientific Data Center of Atomic Bomb Disaster, Nagasaki University School of Medicine. Among the various items examined, the only item that showed a statistical significance was the age at exposure in the cases of squamous cell carcinoma, i.e., those exposed within 2.5 km from the hypocenter were significantly younger than those exposed at 3.0 km or more. (author)

[en] In Report 1 of this series, we suspected that the incidence of skin cancer in Nagasaki A-bomb survivors might have increased based on evidence of chromosomal aberrations and clonal formations in cultured skin cells. In Report 2, we described the results of a preliminary study using 110 cases of skin cancer collected from the three major hospitals in Nagasaki City (Nagasaki University Hospital, A-bomb Hospital and Citizens Hospital). In that study a high correlation was observed between the incidence of skin cancer and exposure distance in the analysis of all 110 cases and of the 50 male cases (p<0.01), but no such correlation was noted in a separate analysis of the 60 female cases. In this report, 140 cases of skin cancer collected from 31 hospitals in Nagasaki City and adjacent districts were statistically analyzed in respect to the estimated distance from the hypocenter, using the data of a total of 66,276 A-bomb survivors recorded in the Scientific Data Center of the Atomic Bomb Disaster, Nagasaki University School of Medicine. The results disclosed a high correlation between the incidence of skin cancer and the exposure distance (p<0.01). In addition, this correlation was the same even when the cases were analyzed separately according to sex. (author)

[en] Published in summary form only

[en] The purpose of this study is to build a system for effective dose display immediately after the gastric cancer X-ray screening. The regression equation of effective dose and dose area product (DAP) was introduced from the data of 500 persons including DAP and effective dose calculated using program for X-ray Monte Carlo. The effective dose was 5.39 mSv of median, 1.18 mSv of minimum, and 38.38 mSv of maximum. The regression equation was Y=0.354+0.0003772X (Y: effective dose, mSv, X: DAP, mGy cm2). Using the regression equation, the effective dose can be estimated from DAP and displayed just after the individual screening. 'Effective dose display system' was constructed to display effective dose immediately after gastric cancer X-ray screening. This system is on the way to be reformed by improving the regression equation on larger data. (author)