73 research outputs found
Multiscale approach to radiation damage induced by ion beams: complex DNA damage and effects of thermal spikes
We present the latest advances of the multiscale approach to radiation damage
caused by irradiation of a tissue with energetic ions and report the most
recent advances in the calculations of complex DNA damage and the effects of
thermal spikes on biomolecules. The multiscale approach aims to quantify the
most important physical, chemical, and biological phenomena taking place during
and following irradiation with ions and provide a better means for
clinically-necessary calculations with adequate accuracy. We suggest a way of
quantifying the complex clustered damage, one of the most important features of
the radiation damage caused by ions. This method can be used for the
calculation of irreparable DNA damage. We include thermal spikes, predicted to
occur in tissue for a short time after ion's passage in the vicinity of the
ions' tracks in our previous work, into modeling of the thermal environment for
molecular dynamics analysis of ubiquitin and discuss the first results of these
simulations.Comment: 14 pages, 3 figures, submitted to EPJ
Molecular dynamics study of accelerated ion-induced shock waves in biological media
We present a molecular dynamics study of the effects of carbon- and iron-ion induced shock waves in DNA duplexes in liquid water. We use the CHARMM force field implemented within the MBN Explorer simulation package to optimize and equilibrate DNA duplexes in liquid water boxes of different sizes and shapes. The translational and vibrational degrees of freedom of water molecules are excited according to the energy deposited by the ions and the subsequent shock waves in liquid water are simulated. The pressure waves generated are studied and compared with an analytical hydrodynamics model which serves as a benchmark for evaluating the suitability of the simulation boxes. The energy deposition in the DNA backbone bonds is also monitored as an estimation of biological damage, something which is not possible with the analytical model
A multi-scale approach to the physics of ion beam cancer therapy
We propose a multi-scale approach to understanding physics related to the
ion/proton-beam cancer therapy and calculation of the probability of the DNA
damage as a result of irradiation of patients with energetic (up to 430 MeV/u)
ions. This approach is inclusive with respect to different scales starting from
the long scale defined by the ion stopping followed by a smaller scale defined
by secondary electrons and radicals ending with the shortest scale defined by
interactions of secondaries with the DNA. We present calculations of the
probabilities of single and double strand breaks of the DNA and suggest a way
of further elaboration of such calculations.Comment: submitted to RADAM2008 proceedings. 8 pages,5 Figures, class files
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