{"created":"2023-05-15T14:50:43.402947+00:00","id":69357,"links":{},"metadata":{"_buckets":{"deposit":"1d0dcde3-8081-405d-bc9e-bad3b2e22144"},"_deposit":{"created_by":1,"id":"69357","owners":[1],"pid":{"revision_id":0,"type":"depid","value":"69357"},"status":"published"},"_oai":{"id":"oai:repo.qst.go.jp:00069357","sets":["10:28"]},"author_link":["680672","680673"],"item_10005_date_7":{"attribute_name":"発表年月日","attribute_value_mlt":[{"subitem_date_issued_datetime":"2008-06-12","subitem_date_issued_type":"Issued"}]},"item_10005_description_5":{"attribute_name":"抄録","attribute_value_mlt":[{"subitem_description":"It is well known that with increasing particle linear energy transfer (LET) the intra track radical process becomes increasingly important in the heavy particle radiolysis of water. By comparison, the inter track radical process is more dominant in low LET photon radiolysis. Thus, the consecutive molecular recruitment after radiation exposure is different for high LET particle exposure and low LET photon exposure. For this reason we evaluated 1) the generation of hydroxyl radicals (OH) in water by ESR spin trapping method using 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) as a spin trapping agent and 2) the generation of 8-hydroxydeoxyguanosine (8-OHdG) in DNA by HPLC with an electrochemical detector (ECD), to investigate the underlying chemical process leading to molecular cascades.\nIn the present study, pure water containing 200 mM DMPO and pure water containing 1.0 mg/ml salmon sperm DNA were irradiated with heavy-ion beams at dose of 20 Gy and 10 Gy, respectively. To investigate the effect of oxygen on the generation of &#183;OH and 8-OHdG, the samples were irradiated under atmospheric or deaerated conditions. Irradiation using four ion species at five different energies (carbon, 290 MeV/n and 135 MeV/n; neon, 400 MeV/n; silicon, 490 MeV/n; and argon, 500 MeV/n) was carried out at NIRS-HIMAC in Japan. Each type of ion beams was irradiated at three different LET values, using PMMA plates of varying thickness to attenuate the irradiation energy: C (290), 20, 80 keV/um; C (135), 25, 95 keV/um; Ne, 30, 82, 100 keV/um; Si, 80, 300 keV/um; and Ar, 100, 230 keV/um. In order to compare the effects of high-LET heavy-ion irradiation and low-LET photon irradiation, identical samples were also irradiated with x-rays (200 kV, 20 mA; approximately 2 keV/um) under the same conditions.\nFor each type of ion irradiation, the amounts of both OH and 8-OHdG (Fig. 1) formed decreased logarithmically as LET (keV/um) increased. The amount of &#183;OH produced at 90 keV/um, however, still reached approximately 50% of that of x-ray radiolysis, suggesting the importance of indirect effect. The amounts of OH and 8-OHdG formed at each LET value became greater as the atomic number of the irradiating ions increased (C<Ne<Si<Ar). The results obtained for aerated and deaerated samples revealed the same pattern; however, significantly smaller amounts of &#183;OH and 8-OHdG were formed under deaerated conditions. These findings would be meaningful in predicting the biological effect of OH generated by high-LET heavy-ion irradiation under both aerated and deaerated conditions along the projection of beams for cancer therapy.","subitem_description_type":"Abstract"}]},"item_10005_description_6":{"attribute_name":"会議概要（会議名, 開催地, 会期, 主催者等）","attribute_value_mlt":[{"subitem_description":"10th International Workshop on Radiation Damage to DNA","subitem_description_type":"Other"}]},"item_access_right":{"attribute_name":"アクセス権","attribute_value_mlt":[{"subitem_access_right":"metadata only access","subitem_access_right_uri":"http://purl.org/coar/access_right/c_14cb"}]},"item_creator":{"attribute_name":"著者","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"Moritake, Takashi"}],"nameIdentifiers":[{"nameIdentifier":"680672","nameIdentifierScheme":"WEKO"}]},{"creatorNames":[{"creatorName":"盛武 敬","creatorNameLang":"en"}],"nameIdentifiers":[{"nameIdentifier":"680673","nameIdentifierScheme":"WEKO"}]}]},"item_language":{"attribute_name":"言語","attribute_value_mlt":[{"subitem_language":"eng"}]},"item_resource_type":{"attribute_name":"資源タイプ","attribute_value_mlt":[{"resourcetype":"conference object","resourceuri":"http://purl.org/coar/resource_type/c_c94f"}]},"item_title":"Measurement of hydroxyl radicals and 8-hydroxydeoxyguanosine induced by High-LET heavy-ion irradiation","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"Measurement of hydroxyl radicals and 8-hydroxydeoxyguanosine induced by High-LET heavy-ion irradiation"}]},"item_type_id":"10005","owner":"1","path":["28"],"pubdate":{"attribute_name":"公開日","attribute_value":"2008-06-16"},"publish_date":"2008-06-16","publish_status":"0","recid":"69357","relation_version_is_last":true,"title":["Measurement of hydroxyl radicals and 8-hydroxydeoxyguanosine induced by High-LET heavy-ion irradiation"],"weko_creator_id":"1","weko_shared_id":-1},"updated":"2023-05-15T20:15:28.282543+00:00"}