Purpose: To determine the increases in SSB and DSB yields after post gamma-irradiation incubation of plasmid DNA with the Escherichia coli base excision repair endonucleases formamidopyrimidine-DNA N-glycosylase (FPG) and endonuclease III (endo III).
Materials And Methods: Aqueous solutions of plasmid DNA were irradiated with 137Cs gamma-rays in the presence of 10(-4) - 10(-1) mol dm(-3) formate. After irradiation, aliquots were treated with FPG and/or endo III. SSB and DSB yields were then determined using gel electrophoresis.
Results: Both SSB and DSB yields were found to increase after enzyme incubation, with the increase in the DSB yield being approximately equal to the square of the increase in the SSB yield. The correlation between the increases in the SSB and DSB yields was unaffected by the scavenger concentration during irradiation.
Conclusion: Under the conditions used, the majority of DSB appear to be formed from two hydroxyl radical attacks.
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http://dx.doi.org/10.1080/09553000050176234 | DOI Listing |
Radiat Oncol
January 2025
Department of Oncology, First Affiliated Hospital of Gannan Medical University, Ganzhou, China.
Purpose: To determine the dosimetric effects of set-up errors on boost coverage, and compares skin toxicity of sequential and simultaneous boost techniques for left-sided breast cancer.
Materials And Methods: This retrospective study included 23 early-stage breast cancer cases. Single isocenter HFWBI-SIB(s-SIB), single isocenter HFWBI-SB(s-SB) and dual isocenter HFWBI-SB(d-SB) were planing.
Sci Rep
January 2025
Institut für Chemie, Universität Potsdam, 14476, Potsdam, Germany.
The quantification of different structures, isoforms and types of damage in plasmid DNA is of importance for applications in radiation research, DNA based bio-dosimetry, and pharmaceutical applications such as vaccine development. The standard method for quantitative analysis of plasmid DNA damage such as single-strand breaks (SSB), double-strand breaks (DSB) or various types of base-damage is Agarose gel electrophoresis (AGE). Despite being well established, AGE has various drawbacks in terms of time consuming handling and analysis procedures.
View Article and Find Full Text PDFInt J Mol Sci
November 2024
Department of Health Physics and Diagnostic Sciences, University of Nevada Las Vegas, 4505 S. Maryland Parkway, Box 453037, Las Vegas, NV 89154, USA.
Simple and complex clustered DNA damage represent the critical initial damage caused by radiation. In this paper, a multinomial probability model of clustered damage is developed with probabilities dependent on the energy imparted to DNA and surrounding water molecules. The model consists of four probabilities: (A) direct damage of sugar-phosphate moieties leading to SSB, (B) OH radical formation with subsequent SSB and BD formation, (C) direct damage to DNA bases, and (D) energy imparted to histone proteins and other molecules in a volume not leading to SSB or BD.
View Article and Find Full Text PDFIn this Letter, a complex-valued double-sideband 16QAM (CV-DSB-16QAM) signaling scheme is proposed and experimentally demonstrated in a 100-Gb/s intensity modulation/direct detection (IM/DD) interconnection system. Unlike the conventional real-valued double-sideband (DSB) quadrature amplitude modulation (QAM) of relatively lower spectral efficiency (SE) and single-sideband (SSB) QAM relying on sharp-edged optical filtering, the CV-DSB-16QAM signal is generated by combining two independent sideband modulated QPSK signals using a single intensity modulator with an optical filtering-free profile, which also saves one photodiode and one analog-to-digital-converter compared with the twin-SSB scheme. Compared to typical pulse amplitude modulation or SSB schemes, the proposed approach offers a compelling alternative for complex-valued DD systems' evolution, particularly in scenarios with high SE demands and controllable chromatic dispersion.
View Article and Find Full Text PDFSci Rep
December 2024
Faculty of Science, Department of Physics, University of Guilan, Namjoo Avenue, P.O. Box 41635 - 1914, Rasht, 4193833697, Iran.
Charged particle radiation can, directly and indirectly, affect cells by breaking DNA strands. This effect includes DNA single-strand breaks (SSB) and DNA double-strand breaks (DSB), which may cause cell death and mitotic failure. Thus, using short-range charged particles such as Auger electrons (AEs) not only leads to the destruction of the target cell but also prevents the nearby healthy cells from exposing to ionizing radiation.
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