[Coloquio de Física 2016-II] «How does radiation cause damage to DNA? Insights from ab initio simulations» (Jorge Kohanoff)
The initial stage of the irradiation process, both via energetic particles or electromagnetic radiation, consists of ionizing the material generating secondary electrons and holes. These species diffuse through the sample experiencing inelastic collisions with the medium until they find an opportunity to react, producing chemical modifications that can lead to various types of damage. In the case of biological matter, damage to the genetic component (DNA) may cause the arrest of the cell cycle. It is linked to diseases like cancer and constitutes the basis for radiotherapies. But materials are subject to ionizing radiation in many other areas, such as radiation detectors, electronic devices in spacecrafts and satellites, structural components in nuclear power plants, and nuclear waste forms encapsulating disposed radioactive fuel and contaminated components. While the type of damage and its consequences depend on the specific material and application, the underlying physics is quite similar, and it is related to the fate of secondary electrons and holes.
We are studying the problem of electron and hole localization and chemical reactivity in a variety of systems using electronic structure calculations and first-principles molecular dynamics simulations (FPMD). Here I will present an assessment of the role of secondary electrons in the microscopic mechanisms that lead to DNA damage in a realistic environment, i.e. in the condensed phase and under thermal fluctuations. I will discuss the emergent picture in which a variety of protection mechanisms, which are not present in gas phase models, influence the feasibility of strand breaks. I will then briefly mention the work we are doing on other systems of interest.
Conferencista: Jorge Kohanoff, Atomistic Simulation Centre, Universidad Queen’s de Belfast, Belfast, Reino Unido
Fecha y hora: viernes 21 de octubre de 2016, 11:00
Lugar: aula 203 (auditorio José Granés) del edificio 405, UN sede Bogotá (ver mapa)
Esta conferencia forma parte del Coloquio de Física UN 2016-II
[Boletín UN Investiga 319, 20 de octubre de 2016]