WEKO3
アイテム
ELUCIDATION OF THE MECHANISMS UNDERLYING ULTRA-HIGH DOSE RATE IRRADIATION
https://repo.qst.go.jp/records/2002565
https://repo.qst.go.jp/records/20025653ddf8017-6115-4267-9db0-5d909362293b
| アイテムタイプ | 会議発表用資料 / Presentation(1) | |||||||
|---|---|---|---|---|---|---|---|---|
| 公開日 | 2025-12-17 | |||||||
| タイトル | ||||||||
| タイトル | ELUCIDATION OF THE MECHANISMS UNDERLYING ULTRA-HIGH DOSE RATE IRRADIATION | |||||||
| 言語 | en | |||||||
| 言語 | ||||||||
| 言語 | eng | |||||||
| 資源タイプ | ||||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_6670 | |||||||
| 資源タイプ | conference poster | |||||||
| 著者 |
楠本 多聞
× 楠本 多聞
|
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| 抄録 | ||||||||
| 内容記述 | Background and AimsIt was indicated that radical-radical interactions between different tracks located at the closest locations, and sudden and local reduction of oxygen concentration were one of the mechanisms of the sparing effects of tissues under UHDR irradiation. To elucidate the mechanisms of biological effects under ultra-high dose rate (UHDR) irradiation, we have addressed radiation chemistry and radiation biology experiments.MethodsTo understand the mechanisms of UHDR irradiation, we evaluated changes in yields of water radiolysis species (i.e., OH radicals, hydrated electrons and hydrogen peroxide), and strand breaks of pBR322 plasmid DNA under clinical energy protons in an average dose rate range from 0.1 to 50 Gy/s. Here, the concentration of OH radical scavenger, Tris-HCl solution, was varied from 10 to 900 mM to investigate the contribution of OH radicals for DNA strand breaks.ResultsPrimary yields of OH radicals and hydrated electrons decrease monotonically with increasing dose rate. In comparison, yields of hydrogen peroxide increase very slightly with dose rate, when we add methanol and sodium nitrate, both of which are scavengers of OH radicals and hydrated electrons, respectively, that decompose hydrogen peroxide formed by water radiolysis. No significant dose rate dependence of DNA single strand breaks is seen at the Tris-HCl concentration of 10 and 100 mM, corresponding the scavenging time scale of 9 and 90 ns. In comparison, a significant reduction is observed at 900 mM (i.e., scavenging time scale of 1 ns).ConclusionsThe present findings implied that radical-radical reactions occurred in the early chemical stage (~ 10 ns) contribute to the reduction of DNA damage, leading the sparing effects of healthy tissues. | |||||||
| 会議概要（会議名, 開催地, 会期, 主催者等） | ||||||||
| 内容記述 | FRPT2025 | |||||||
| 発表年月日 | ||||||||
| 日付 | 2025-12-11 | |||||||
