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Full-Text Articles in Physics
Simulation Of A Microdosimetry Problem: Behavior Of A Pseudorandom Series At A Low Probability, P. Meyer, J. E. Groetz, Robert Katz, M. Fromm, A. Chambaudet
Simulation Of A Microdosimetry Problem: Behavior Of A Pseudorandom Series At A Low Probability, P. Meyer, J. E. Groetz, Robert Katz, M. Fromm, A. Chambaudet
Robert Katz Publications
The carcinogenic effects for low dose irradiations are not very well known. Estimations usually are made based on the effects observed at high doses that are then extrapolated to low doses. To estimate low dose effects, the ICRP (International Commission on Radiological Protection) uses a linear extrapolation matched with a dose-rate reduction factor equal to two. This proportionality of the effect and dose, even for the lowest doses and dose-rates, leads to two assumptions which must be questioned :
1. the efficiency of DNA repair in cells does not vary with the dose and the dose-rate,
2. when one single …
Calculation Of Heavy Ion Inactivation And Mutation Rates In Radial Dose Model Of Track Structure, Francis A. Cucinotta, John W. Wilson, Mark R. Shavers, Robert Katz
Calculation Of Heavy Ion Inactivation And Mutation Rates In Radial Dose Model Of Track Structure, Francis A. Cucinotta, John W. Wilson, Mark R. Shavers, Robert Katz
Robert Katz Publications
In the track structure model, the inactivation cross section is found by summing an inactivation probability over all impact parameters from the ion to the sensitive sites within the cell nucleus. The inactivation probability is evaluated by using the dose response of the system to gamma rays and the radial dose of the ions and may be equal to unity at small impact parameters. We apply the track structure model to recent data with heavy ion beams irradiating biological samples of E. Coli, Bacillus Subtilis spores, and Chinese hamster (V79) cells. Heavy ions have observed cross sections for inactivation that …
Radial Dose Model Of Ssb, Dsb, Deletions And Comparisons To Montecarlo Track Structure Simulations, Francis A. Cucinotta, H. Nikjoo, J. W. Wilson, Robert Katz, D. T. Goodhead
Radial Dose Model Of Ssb, Dsb, Deletions And Comparisons To Montecarlo Track Structure Simulations, Francis A. Cucinotta, H. Nikjoo, J. W. Wilson, Robert Katz, D. T. Goodhead
Robert Katz Publications
The initial lesions formed in DNA by ionizing radiation include base damage, single strand breaks (SSB), double strand breaks (DSB), DNA cross links, and deletions. Deletions occur through energy deposition and perhaps more importantly through recombination repair of DSB's. Several mechanisms for the formation of DSB's and deletions related to energy deposition can be considered. Track simulation codes have indicated the importance of clusters of ionizations in small volumes similar to the size of a nucleosome. These clusters have been related to several types of damage to DNA, including DSB and deletions resulting from multiple DSB's formed by single electron …