Linked Life Data

14995058

Source:http://linkedlifedata.com/resource/pubmed/id/14995058

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2004-3-3
pubmed:abstractText
There is a growing interest in the study of interactions of ionizing radiation with condensed matter at the nanometer level. The motivation for this research is the hypothesis that the number of ionizations occurring within short segments of DNA-size subvolumes is a major factor determining the biological effectiveness of ionizing radiation. A novel dosimetry technique, called nanodosimetry, measures the spatial distribution of individual ionizations in an irradiated low-pressure gas model of DNA. The measurement of nanodosimetric event size spectra may enable improved characterization of radiation quality, with applications in proton and charged-particle therapy, radiation protection, and space research. We describe an ion-counting nanodosimeter developed for measuring radiation-induced ionization clusters in small, wall-less low-pressure gas volumes, simulating short DNA segments. It measures individual radiation-induced ions, deposited in 1 Torr propane within a tissue-equivalent cylindrical volume of 2-4 nm diameter and up to 100 nm length. We present first ionization cluster size distributions obtained with 13.6 MeV protons, 4.25 MeV alpha particles and 24.8 MeV carbon nuclei in propane; they correspond to a wide LET range of 4-500 keV/microm. We are currently developing plasmid-based assays to characterize the local clustering of DNA damage with biological methods. First results demonstrate that there is increasing complexity of DNA damage with increasing LET. Systematic comparison of biological and nanodosimetric data will help us to validate biophysical models predicting radiation quality based on nanodosimetric spectra. Possible applications for charged particle radiation therapy planning are discussed.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0158-9938
pubmed:author
pubmed:issnType
Print
pubmed:volume
26
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
149-55
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Ion-counting nanodosimetry: current status and future applications.
pubmed:affiliation
Dept. of Radiation Medicine, Loma Linda University Medical Center, Loma Linda, California 92354, USA. rschulte@dominion.llumc.edu
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Review, Research Support, Non-U.S. Gov't