Published September 8, 2004 | Version v1
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'K' contribution to the biological effect of ionizing radiations

Creators

Description

The aim of this work is to determine the importance of 'K' ionizations on DNA as critical physical events initiating the biological effects of ionizing radiation, in particular in human cells. Ultra-soft X-rays are used as a probe of core ionization events. A decisive test consists in comparing the biological effects at 250 eV and 350 eV (before and after the carbon K - threshold). The results show a sharp increase of the biological efficiency for both cellular inactivation and chromosomal exchange aberration above the carbon K-threshold, correlated with the one of core events occurring in DNA atoms. The heavy ion irradiation displays again the paradoxical behaviour of cellular inactivation cross sections as a function of LET. Finally, the 'K' event contribution to cellular inactivation of usual low LET radiation is estimated to be about 75%. (author)

Abstract (French)

Le but de ce travail est de determiner l'importance des ionisations 'K' sur l'ADN en tant qu'evenements physiques critiques a l'origine des effets biologiques des rayonnements ionisants en particulier dans les cellules humaines. Les rayons X ultra-mous sont utilises comme sonde des evenements d'ionisations de coeur. Un test decisif consiste a comparer les effets biologiques a 250eV et 350eV (avant et apres le seuil K du carbone). Les resultats montrent un fort accroissement de l'efficacite biologique pour l'inactivation cellulaire et la production d'aberrations chromosomiques d'echange au passage du seuil K du carbone, correle avec celui des evenements de coeur produits dans les atomes de l'ADN. L'irradiation en ions lourds a permis de retrouver le comportement paradoxal des sections efficaces d'inactivation cellulaire en fonction du TEL. La contribution des evenements 'K' a l'inactivation cellulaire des rayonnements usuels de bas TEL est estimee a -75%

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Additional details

Additional titles

Original title (French)
Contribution 'K' a l'effet biologique des rayonnements ionisants

Identifiers

URL
http://www.iaea.org/inis/Contacts/;

Publishing Information

Imprint Pagination
185 p.
Report number
FRCEA-TH--2068

INIS

Country of Publication
France
Country of Input or Organization
France
INIS RN
46133714
Subject category
S63: RADIATION, THERMAL, AND OTHER ENVIRONMENTAL POLLUTANT EFFECTS ON LIVING ORGANISMS AND BIOLOGICAL MATERIALS;
Resource subtype / Literary indicator
Thesis
Descriptors DEI
ANIMAL CELLS; BIOLOGICAL EFFECTS; CHROMOSOMAL ABERRATIONS; CROSS SECTIONS; DNA; INACTIVATION; LET; SOFT X RADIATION; SYNCHROTRON RADIATION
Descriptors DEC
BREMSSTRAHLUNG; ELECTROMAGNETIC RADIATION; ENERGY TRANSFER; IONIZING RADIATIONS; MUTATIONS; NUCLEIC ACIDS; ORGANIC COMPOUNDS; RADIATIONS; X RADIATION

Optional Information

Notes
100 refs.; Available from the INIS Liaison Officer for France, see the 'INIS contacts' section of the INIS-NKM website for current contact and E-mail addresses: http://www.iaea.org/inis/Contacts/; Also available from Service Commun de la Documentation de l'UPMC, 4 place Jussieu Boite courrier 192, 75252 PARIS CEDEX 05 (France)