Dataset Information

Soft X-ray and low energy electron-induced damage to DNA under N2 and O2 atmospheres.

ABSTRACT: DNA damage induced by low energy electrons (LEEs) and soft X-rays is measured under dry nitrogen and oxygen at atmospheric pressure and temperature. Five-monolayer plasmid DNA films deposited on tantalum and glass substrates are exposed to Al K(?) X-rays of 1.5 keV in the two different environments. From the damage yields for DNA, G values are extracted for X-rays and LEEs. The G values for LEEs are 3.5 and 3.4 higher than those for X-ray photons under N(2) and O(2) atmospheres, respectively. Because most of the measured damage is in the form of single strand breaks (SSB), this result indicates a much higher effectiveness for LEEs relative to X-rays in causing SSB in both environments. The results indicate that the oxygen fixation mechanism, which is highly effective in increasing radiobiological effectiveness, under aerobic conditions, is operative on the type of damage created at the early stage of DNA radiolysis by LEEs.

SUBMITTER: Alizadeh E

PROVIDER: S-EPMC3846624 | biostudies-literature | 2011 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Soft X-ray and low energy electron-induced damage to DNA under N2 and O2 atmospheres.

Alizadeh Elahe E Cloutier Pierre P Hunting Darel D Sanche Léon L

The journal of physical chemistry. B 20110331 15

DNA damage induced by low energy electrons (LEEs) and soft X-rays is measured under dry nitrogen and oxygen at atmospheric pressure and temperature. Five-monolayer plasmid DNA films deposited on tantalum and glass substrates are exposed to Al K(α) X-rays of 1.5 keV in the two different environments. From the damage yields for DNA, G values are extracted for X-rays and LEEs. The G values for LEEs are 3.5 and 3.4 higher than those for X-ray photons under N(2) and O(2) atmospheres, respectively. Be ...[more]

PMID: 21452797

Similar Datasets

Project description:JUNGFRAU (adJUstiNg Gain detector FoR the Aramis User station) is a two-dimensional hybrid pixel detector for photon science applications at free-electron lasers and synchrotron light sources. The JUNGFRAU?0.4 prototype presented here is specifically geared towards low-noise performance and hence soft X-ray detection. The design, geometry and readout architecture of JUNGFRAU?0.4 correspond to those of other JUNGFRAU pixel detectors, which are charge-integrating detectors with 75?µm × 75?µm pixels. Main characteristics of JUNGFRAU?0.4 are its fixed gain and r.m.s. noise of as low as 27?e(-) electronic noise charge (<100?eV) with no active cooling. The 48 × 48 pixels JUNGFRAU?0.4 prototype can be combined with a charge-sharing suppression mask directly placed on the sensor, which keeps photons from hitting the charge-sharing regions of the pixels. The mask consists of a 150?µm tungsten sheet, in which 28?µm-diameter holes are laser-drilled. The mask is aligned with the pixels. The noise and gain characterization, and single-photon detection as low as 1.2?keV are shown. The performance of JUNGFRAU?0.4 without the mask and also in the charge-sharing suppression configuration (with the mask, with a `software mask' or a `cluster finding' algorithm) is tested, compared and evaluated, in particular with respect to the removal of the charge-sharing contribution in the spectra, the detection efficiency and the photon rate capability. Energy-dispersive and imaging experiments with fluorescence X-ray irradiation from an X-ray tube and a synchrotron light source are successfully demonstrated with an r.m.s. energy resolution of 20% (no mask) and 14% (with the mask) at 1.2?keV and of 5% at 13.3?keV. The performance evaluation of the JUNGFRAU?0.4 prototype suggests that this detection system could be the starting point for a future detector development effort for either applications in the soft X-ray energy regime or for an energy-dispersive detection system.

Dataset Information

Soft X-ray and low energy electron-induced damage to DNA under N2 and O2 atmospheres.

Publications

Soft X-ray and low energy electron-induced damage to DNA under N2 and O2 atmospheres.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure