@article{oai:repo.qst.go.jp:00042869,
 author = {Kawata, Tetsuya and Durante, Marco and Furusawa, Yoshiya and George, Kerry and Ito, Hisao and Wu, Honglu and A, Cucinotta Francesca and 川田 哲也 and 古澤 佳也 and ジョージ ケリー and 伊東 久夫 and ウー ホングル and クシノッタ フランク},
 journal = {Advances in Space Research},
 month = {},
 note = {We report measurements of initial G2-chromatid breaks in normal human fibroblasts exposed to various types of high-LET particles. Exponentially growing AG 1522 cells were exposed to gamma-rays or heavy ions. Chromosomes were prematurely condensed by calyculin A. Chromatid-type breaks and isochromatid-type breaks were scored separately. The dose response curves for the induction of total chromatid breaks (chromatid-type + isochromatid-type) and chromatid-type breaks were linear for each type of radiation. However, dose response curves for the induction of isochromatid-type breaks were linear for high-LET radiations and linear-quadratic for gamma-rays. Relative biological effectiveness (RBE), calculated from total breaks, showed a LET dependent tendency with a peak at 55 keV/um silicon (2.7) or 80 keV/um carbon (2.7) and then decreased with LET (1.5 at 440 keV/um). RBE for chromatid-type break peaked at 55 keV/um (2.4) then decreased rapidly with LET. The RBE of 440 keV/um iron particles was 0.7. The RBE calculated from induction of isochromatid-type breaks was much higher for high-LET radiations. It is concluded that the increased production of isochromatid-type breaks, induced by the densely ionizing track structure, is a signature of high-LET radiation exposure.},
 pages = {383--391},
 title = {G2-Chromosome Aberarions Induced by High-LET Radiations.},
 volume = {27},
 year = {2001}
}