Deinococcus radiodurans recovering from the effect of acute dose of gamma (gamma) radiation shows a biphasic mechanism of DNA double strands breaks repair that involves an efficient homologous recombination. However, it shows higher sensitivity to near-UV (NUV) than Escherichia coli and lacks RecBC, a DNA strand break (DSB) repair enzyme in some bacteria. Recombinant Deinococcus expressing the recBC genes of E. coli showed nearly three-fold improvements in near-UV tolerance and nearly 2 log cycle reductions in wild type gamma radiation resistance. RecBC over expression effect on radiation response of D. radiodurans was independent of indigenous RecD. Loss of gamma radiation tolerance was attributed to the enhanced rate of in vivo degradation of radiation damaged DNA and delayed kinetics of DSB repair during post-irradiation recovery. RecBC expressing cells of Deinococcus showed wild type response to Far-UV. These results suggest that the overproduction of RecBC competes with the indigenous mechanism of gamma radiation damaged DNA repair while it supports near-UV tolerance in D. radiodurans.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.dnarep.2007.07.007 | DOI Listing |
Sci Rep
January 2025
REQUIMTE, NOVA School of Science and Technology, University New of Lisbon, Caparica, 2829-516, Portugal.
The presented work is dedicated to the detection of hydrogen, using detectors based on a MAPD (Micropixel Avalanche Photodiode) array based on new MAPD-3NM-2 type photodiodes and two different scintillators (LaBr(Ce) and LSO(Ce)). The physical parameters of the MAPD photodiode used in the study and the intrinsic background of the scintillators were investigated. For the 2.
View Article and Find Full Text PDFAppl Radiat Isot
March 2025
Technical Physics Division, Bhabha Atomic Research Centre, Mumbai, India.
This study shows an implementation of neutron-gamma pulse shape discrimination (PSD) using a two-dimensional convolutional neural network. The inputs to the network are snapshots of the unprocessed, digitized signals from a BC501A detector. By exposing a BC501A detector to a Cf-252 source, neutron and gamma signals were collected to create a training dataset.
View Article and Find Full Text PDFPhys Med
January 2025
Department of Radiation Oncology, IRCCS Sacro Cuore Don Calabria Hospital, Via Don A. Sempreboni 5, 37024 Negrar di Valpolicella, VR, Italy; University of Brescia, Brescia, Italy.
Purpose: Adaptive MRgRT by 1.5 T MR-linac requires independent verification of the plan-of-the-day by the primary TPS (Monaco) (M). Here we validated a Monte Carlo-based dose-check including the magnetostatic field, SciMoCa (S).
View Article and Find Full Text PDFJ Environ Radioact
January 2025
Plant Breeding and Genetics Sub-programme, Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture, Vienna International Centre, P.O. Box 100, 1400, Vienna, Austria.
Groundnut (Arachis hypogaea L.) is a popular nutritious food crop in the world. In Namibia, groundnut varieties are limited and characterized by low yields of 0.
View Article and Find Full Text PDFJ Clin Neurosci
January 2025
Department of Neurological Surgery and Rosa Ella Burkhardt Brain Tumor & Neuro-Oncology Center, Cleveland Clinic, Cleveland, OH, USA; Cleveland Clinic Lerner College of Medicine of Case Western Reserve University. Electronic address:
Background And Objective: Radiosurgery can serve as a primary, adjuvant, or salvage treatment modality for cavernous sinus tumors (CST), providing high tumor control. However, particularly with cavernous sinus expansion, there may be insufficient distance from the optic apparatus to perform radiosurgery safely. The internal carotid artery adjacent to the distal dural ring (ICAddr), when enhancing similarly to the CST, can be difficult to delineate, and can lead to over-contouring of target volume near the optic nerve and therefore increasing the risk of radiation-induced optic toxicity.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!