Most recent dissemination activities:
Modeling secondary particle tracks generated by intermediate- and low-energy protons in water with the Low-Energy Particle Track Simulation code

Using a recent extension of the Low-Energy Particle Track Simulation (LEPTS) Monte Carlo code, we model the slowing-down of heavy charged particles propagating in water, combined with an explicit molecular-level description of radiation effects due to the formation of secondary electrons, their propagation through the medium, and electron-induced molecular dissociations.

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Gold nanoparticles for cancer radiotherapy: a review

Radiotherapy is currently used in around 50% of cancer treatments and relies on the deposition of energy directly into tumour tissue. Although it is generally effective, some of the deposited energy can adversely affect healthy tissue outside the tumour volume, especially in the case of photon radiation (gamma and X-rays). Improved radiotherapy outcomes can be achieved by employing ion beams due to the characteristic energy deposition curve which culminates in a localised, high radiation dose (in form of a Bragg peak).

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Toward the exploration of the NiTi phase diagram with a classical force field

Classical force fields, used for atomistic modeling of metal materials, are typically constructed to match low-temperature properties obtained in experiments or from quantum-level calculations. However, force fields can systematically fail to reproduce further fundamental parameters, such as the melting point. In this work, we present a modified force field for modeling metallic compounds, which has been implemented in the MBN Explorer software package.

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Photoionization of multishell fullerenes studied by ab initio and model approaches

Photoionization of two buckyonions, C60@C240 and C20@C60, is investigated by means of time-dependent density-functional theory (TDDFT). The TDDFT-based photoabsorption spectrum of C60@C240, calculated in a broad photon energy range, resembles the sum of spectra of the two isolated fullerenes, thus illustrating the absence of strong plasmonic coupling between the fullerenes which was proposed earlier.

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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.

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Modeling of nanoparticle coatings for medical applications

Gold nanoparticles (AuNPs) have been shown to possess properties beneficial for the treatment of cancerous tumors by acting as radiosensitizers for both photon and ion radiation. Blood circulation time is usually increased by coating the AuNPs with poly(ethylene glycol) (PEG) ligands. The effectiveness of the PEG coating, however, depends on both the ligand surface density and length of the PEG molecules, making it important to understand the structure of the coating.

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Preclinical evaluation of gold-DTDTPA nanoparticles as theranostic agents in prostate cancer radiotherapy

Aim: Gold nanoparticles have attracted significant interest in cancer diagnosis and treatment. Herein, we evaluated the theranostic potential of dithiolated diethylenetriamine pentaacetic acid (DTDTPA) conjugated AuNPs (Au@DTDTPA) for CT-contrast enhancement and radiosensitization in prostate cancer. Materials & methods: In vitro assays determined Au@DTDTPA uptake, cytotoxicity, radiosensitizing potential and DNA damage profiles.

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Multiscale approach predictions for biological outcomes in ion-beam cancer therapy

Ion-beam therapy provides advances in cancer treatment, offering the possibility of excellent dose localization and thus maximising cell-killing within the tumour. The full potential of such therapy can only be realised if the fundamental mechanisms leading to lethal cell damage under ion irradiation are well understood. The key question is whether it is possible to quantitatively predict macroscopic biological effects caused by ion radiation on the basis of physical and chemical effects related to the ion-medium interactions on a nanometre scale.

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Energy deposited by secondary electrons generated by swift proton beams through polymethylmethacrylate

The ionization yield of ion tracks in polymers and biomolecular systems reaches a maximum, known as the Bragg peak, close to the end of the ion trajectories. Along the path of the ions through the materials, many electrons are generated, which produce a cascade of further ionizations and, consequently, a shower of secondary electrons. Among these, very low energy secondary electrons can produce damage in the biomolecules by dissociative electron attachment.

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Cross sections for ionization of tetrahydrofuran by protons at energies between 300 and 3000 keV

Double-differential cross sections for ionization of tetrahydrofuran by protons with energies from 300 to 3000 keV were measured at the Physikalisch-Technische Bundesanstalt ion accelerator facility. The electrons emitted at angles between 15° and 150° relative to the ion-beam direction were detected with an electrostatic hemispherical electron spectrometer. Single-differential and total ionization cross sections have been derived by integration.

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