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Miloš Lokajíček

Publications and source records attributed to Miloš Lokajíček.

4 recordsLinked to original sources
arXiv2006

Mechanism of cell inactivation by different ions: Damage induction probabilities per single tracks

Biological effects of proton and light ion irradiations have been studied in detail by analyzing published cell survival data with the help of the probabilistic two-stage radiobiological model. Probabilities of single ion tracks to induce lesions of different severity have been assessed in dependence on their linear energy transfer (LET). The results are presented and their interpretation in terms of $Z_{eff}^2/β^2$ (the effective charge over velocity squared) is discussed.

physics.bio-ph↗
arXiv2005

Detailed analysis of the response of different cell lines to carbon irradiation

Published survival data for Chinese hamster ovarian cells CHO-K1 and their radiosensitive mutant xrs5 after irradiation by carbon ions of energies from 2.4 to 266.4 MeV/u have been analyzed using the probabilistic two-stage radiobiological model, which enables to represent the interplay of damage induction and repair processes. The results give support for the hypothesis that the differences in radiation sensitivity of diverse cell lines are given primarily by their different repair capabilities, and indicate the need for explicitly representing the outcome of repair processes in radiobiological models and treatment planning approaches in radiotherapy.

physics.bio-ph↗
arXiv2004

Probabilistic two-stage model of cell inactivation by ionizing particles

Model of biological effects of ionizing particles, especially of protons and other ions, is proposed. The model is based on distinguishing the single-particle and collective effects of the underlying radiobiological mechanism. The probabilities of individual particles to form severe damages to DNA, their synergetic or saturation combinations, and the effect of cellular repair system are taken into account. The model enables to describe linear, parabolic and more complex curves, including those exhibiting low-dose hypersensitivity phenomena, in a systematic way. Global shape as well as detailed structure of survival curves might be represented, which is crucial if different fractionation schemes in radiotherapy should be assessed precisely. Experimental cell-survival data for inactivation of V79 cells by low-energy protons have been analyzed and corresponding detailed characteristics of the inactivation mechanism have been derived for this case.

physics.bio-ph↗