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The interaction of heavy charged particles with DNA is of interest for several areas, from hadrontherapy to aero-space industry. In this paper, a TD-DFT study on the interaction of a 4 keV proton with an isolated DNA base pair was carried out. Ehrenfest dynamics was used to study the evolution of the system during and after the proton impact up to about 193 fs. This time was long enough to observe the dissociation of the target, which occurs between 80-100 fs. The effect of base pair linking to the DNA double helix was emulated by fixing the four O3 atoms responsible for the attachment. The base pair tends to dissociate into its main components, namely the phosphate groups, sugars and nitrogenous bases. A central impact with energy transfer of 17.9 eV only produces base damage while keeping the backbone intact. An impact on a phosphate group with energy transfer of about 60 eV leads to backbone break at that site together with base damage, while the opposite backbone site integrity is kept is this situation. As the whole system is perturbed during such a collision, no atom remains passive. These results suggest that base damage accompanies all backbone breaks since hydrogen bonds that keep bases together are much weaker that those between the other components of the DNA.
We employ Real-Time Time-Dependent Density Functional Theory to study hole oscillations within a B-DNA monomer (one base pair) or dimer (two base pairs). Placing the hole initially at any of the bases which make up a base pair, results in THz oscilla
Cytosine methylation has been found to play a crucial role in various biological processes, including a number of human diseases. The detection of this small modification remains challenging. In this work, we computationally explore the possibility o
The photosystem II reaction centre is the photosynthetic complex responsible for oxygen production on Earth. Its water splitting function is particularly favoured by the formation of a stable charge separated state via a pathway that starts at an acc
Ion beam therapy is one of the most progressive methods in cancer treatment. Studies of the water radiolysis process show that the most long-living species that occur in the medium of a biological cell under the action of ionizing irradiation are hyd
The Geant4-DNA project proposes to develop an open-source simulation software based and fully included in the general-purpose Geant4 Monte Carlo simulation toolkit. The main objective of this software is to simulate biological damages induced by ioni