1
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Tran HN, Archer J, Baldacchino G, Brown JMC, Chappuis F, Cirrone GAP, Desorgher L, Dominguez N, Fattori S, Guatelli S, Ivantchenko V, Méndez JR, Nieminen P, Perrot Y, Sakata D, Santin G, Shin WG, Villagrasa C, Zein S, Incerti S. Review of chemical models and applications in Geant4-DNA: Report from the ESA BioRad III Project. Med Phys 2024. [PMID: 38889367 DOI: 10.1002/mp.17256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 05/17/2024] [Accepted: 05/25/2024] [Indexed: 06/20/2024] Open
Abstract
A chemistry module has been implemented in Geant4-DNA since Geant4 version 10.1 to simulate the radiolysis of water after irradiation. It has been used in a number of applications, including the calculation of G-values and early DNA damage, allowing the comparison with experimental data. Since the first version, numerous modifications have been made to the module to improve the computational efficiency and extend the simulation to homogeneous kinetics in bulk solution. With these new developments, new applications have been proposed and released as Geant4 examples, showing how to use chemical processes and models. This work reviews the models implemented and application developments for modeling water radiolysis in Geant4-DNA as reported in the ESA BioRad III Project.
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Affiliation(s)
| | - Jay Archer
- Centre For Medical and Radiation Physics, University of Wollongong, Wollongong, New South Wales, Australia
| | - Gérard Baldacchino
- Université Paris-Saclay, CEA, LIDYL, Gif-sur-Yvette, France
- CY Cergy Paris Université, CEA, LIDYL, Gif-sur-Yvette, France
| | - Jeremy M C Brown
- Optical Sciences Centre, Department of Physics and Astronomy, School of Science, Swinburne University of Technology, Melbourne, Australia
| | - Flore Chappuis
- Institute of Radiation Physics (IRA), Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Giuseppe Antonio Pablo Cirrone
- Istituto Nazionale di Fisica Nucleare (INFN), Laboratori Nazionali del Sud (LNS), Catania, Italy
- Centro Siciliano di Fisica Nucleare e Struttura della Materia, Catania, Italy
| | - Laurent Desorgher
- Institute of Radiation Physics (IRA), Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Naoki Dominguez
- Department of Radiation Oncology, University of California San Francisco, San Francisco, California, USA
| | - Serena Fattori
- Istituto Nazionale di Fisica Nucleare (INFN), Laboratori Nazionali del Sud (LNS), Catania, Italy
| | - Susanna Guatelli
- Centre For Medical and Radiation Physics, University of Wollongong, Wollongong, New South Wales, Australia
| | | | - José-Ramos Méndez
- Department of Radiation Oncology, University of California San Francisco, San Francisco, California, USA
| | | | - Yann Perrot
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Fontenay-aux-Roses, France
| | - Dousatsu Sakata
- Centre For Medical and Radiation Physics, University of Wollongong, Wollongong, New South Wales, Australia
- Division of Health Sciences, Osaka University, Osaka, Japan
- School of Physics, University of Bristol, Bristol, UK
| | | | - Wook-Geun Shin
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, Massachusetts, USA
| | - Carmen Villagrasa
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Fontenay-aux-Roses, France
| | - Sara Zein
- Univ. Bordeaux, CNRS, LP2I, UMR 5797, Gradignan, France
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Ameixa J, Bald I. Unraveling the Complexity of DNA Radiation Damage Using DNA Nanotechnology. Acc Chem Res 2024; 57:1608-1619. [PMID: 38780304 PMCID: PMC11154965 DOI: 10.1021/acs.accounts.4c00121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 05/05/2024] [Accepted: 05/09/2024] [Indexed: 05/25/2024]
Abstract
Radiation cancer therapies use different ionizing radiation qualities that damage DNA molecules in tumor cells by a yet not completely understood plethora of mechanisms and processes. While the direct action of the radiation is significant, the byproducts of the water radiolysis, mainly secondary low-energy electrons (LEEs, <20 eV) and reactive oxygen species (ROS), can also efficiently cause DNA damage, in terms of DNA strand breakage or DNA interstrand cross-linking. As a result, these types of DNA damage evolve into mutations hindering DNA replication, leading to cancer cell death. Concomitant chemo-radiotherapy explores the addition of radiosensitizing therapeutics commonly targeting DNA, such as platinum derivatives and halogenated nucleosides, to enhance the harmful effects of ionizing radiation on the DNA molecule. Further complicating the landscape of DNA damage are secondary structures such as G-quadruplexes occurring in telomeric DNA. These structures protect DNA from radiation damage, rendering them as promising targets for new and more selective cancer radiation treatments, rather than targeting linear DNA. However, despite extensive research, there is no single paradigm approach to understanding the mysterious way in which ionizing radiation causes DNA damage. This is due to the multidisciplinary nature of the field of research, which deals with multiple levels of biological organization, from the molecular building blocks of life toward cells and organisms, as well as with complex multiscale radiation-induced effects. Also, intrinsic DNA features, such as DNA topology and specific oligonucleotide sequences, strongly influence its response to damage from ionizing radiation. In this Account, we present our studies focused on the absolute quantification of photon- and low-energy electron-induced DNA damage in strategically selected target DNA sequences. Our methodology involves using DNA origami nanostructures, specifically the Rothemund triangle, as a platform to expose DNA sequences to either low-energy electrons or vacuum-ultraviolet (VUV, <15 eV) photons and subsequent atomic force microscopy (AFM) analysis. Through this approach, the effects of the DNA sequence, incorporation of halogenated radiosensitizers, DNA topology, and the radiation quality on radiation-induced DNA strand breakage have been systematically assessed and correlated with fundamental photon- and electron-driven mechanisms underlying DNA radiation damage. At lower energies, these mechanisms include dissociative electron attachment (DEA), where electrons attach to DNA molecules causing strand breaks, and dissociative photoexcitation of DNA. Additionally, further dissociative processes such as photoionization and electron impact contribute to the complex cascade of DNA damage events induced by ionizing radiation. We expect that emerging DNA origami-based approaches will lead to a paradigm shift in research fields associated with DNA damage and suggest future directions, which can foster the development of technological applications in nanomedicine, e.g., optimized cancer treatments or the molecular design of optimized radiosensitizing therapeutics.
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Affiliation(s)
- João Ameixa
- Institute
of Chemistry, Hybrid Nanostructures, University
of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany
- Centre
of Physics and Technological Research (CEFITEC), Department of Physics,
NOVA School of Science and Technology, University
NOVA of Lisbon, Campus de Caparica 2829-516, Portugal
| | - Ilko Bald
- Institute
of Chemistry, Hybrid Nanostructures, University
of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany
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3
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Bian J, Duran J, Shin WG, Ramos-Méndez J, Sankey JC, Childress L, Seuntjens J, Enger SA. GEANT4-DNA simulation of temperature-dependent and pH-dependent yields of chemical radiolytic species. Phys Med Biol 2023; 68:124002. [PMID: 37230081 DOI: 10.1088/1361-6560/acd90d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 05/25/2023] [Indexed: 05/27/2023]
Abstract
Objective.GEANT4-DNA can simulate radiation chemical yield (G-value) for radiolytic species such as the hydrated electron (eaq-) with the independent reaction times (IRT) method, however, only at room temperature and neutral pH. This work aims to modify the GEANT4-DNA source code to enable the calculation ofG-values for radiolytic species at different temperatures and pH values.Approach.In the GEANT4-DNA source code, values of chemical parameters such as reaction rate constant, diffusion coefficient, Onsager radius, and water density were replaced by corresponding temperature-dependent polynomials. The initial concentration of hydrogen ion (H+)/hydronium ion (H3O+) was scaled for a desired pH using the relationship pH = -log10[H+]. To validate our modifications, two sets of simulations were performed. (A) A water cube with 1.0 km sides and a pH of 7 was irradiated with an isotropic electron source of 1 MeV. The end time was 1μs. The temperatures varied from 25 °C to 150 °C. (B) The same setup as (A) was used, however, the temperature was set to 25 °C while the pH varied from 5 to 9. The results were compared with published experimental and simulated work.Main results.The IRT method in GEANT4-DNA was successfully modified to simulateG-values for radiolytic species at different temperatures and pH values. Our temperature-dependent results agreed with experimental data within 0.64%-9.79%, and with simulated data within 3.52%-12.47%. The pH-dependent results agreed well with experimental data within 0.52% to 3.19% except at a pH of 5 (15.99%) and with simulated data within 4.40%-5.53%. The uncertainties were below ±0.20%. Overall our results agreed better with experimental than simulation data.Significance.Modifications in the GEANT4-DNA code enabled the calculation ofG-values for radiolytic species at different temperatures and pH values.
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Affiliation(s)
- Jingyi Bian
- Medical Physics Unit, Department of Oncology, Faculty of Medicine, McGill University, Montreal, Quebec, Canada
| | - Juan Duran
- Medical Physics Unit, Department of Oncology, Faculty of Medicine, McGill University, Montreal, Quebec, Canada
| | - Wook-Geun Shin
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA-02114, United States of America
| | - Jose Ramos-Méndez
- Department of Radiation Oncology, University of California San Francisco, CA, United States of America
| | - Jack C Sankey
- Department of Physics, McGill University, Montreal, Quebec, Canada
| | - Lilian Childress
- Department of Physics, McGill University, Montreal, Quebec, Canada
| | - Jan Seuntjens
- Medical Physics Unit, Department of Oncology, Faculty of Medicine, McGill University, Montreal, Quebec, Canada
- Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada
| | - Shirin A Enger
- Medical Physics Unit, Department of Oncology, Faculty of Medicine, McGill University, Montreal, Quebec, Canada
- Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, Canada
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Hu A, Qiu R, Wu Z, Zhang H, Li J. CPU-GPU coupling independent reaction times method in NASIC and application in water radiolysis by FLASH irradiation. Biomed Phys Eng Express 2022; 8. [DOI: 10.1088/2057-1976/ac52d9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 02/08/2022] [Indexed: 11/11/2022]
Abstract
Abstract
The mechanism of the FLASH effect remains unclear and could be revealed by studying chemical reactions during irradiation. Monte Carlo simulation of the radiolytic species is an effective tool to analyze chemical reactions, but the simulation is limited by computing costs of the step-by-step simulation of radiolytic species, especially when considering beam with complex time structure. The complexity of the time structure of beams from accelerators in FLASH radiotherapy requires a high-performance Monte Carlo code. In this work, we develop a CPU-GPU coupling accelerating code with the independent reaction times (IRT) method to extend the chemical module of our nanodosimetry Monte Carlo code NASIC. Every chemical molecule in the microenvironment contains time information to consider the reactions from different tracks and simulate beams with complex time structures. Performance test shows that our code significantly improved the computing efficiency of the chemical module by four orders of magnitude. Then the code is used to study the oxygen depletion hypothesis in FLASH radiotherapy for different conditions by setting different parameters. The transient oxygen consumption rate values in the water are calculated when the pulses width ranges from 2 ps to 2 μs, the total dose ranges from 0.5 Gy to 100 Gy and the initial oxygen concentration ranges from 0.1% to 21%. The time evolution curves are simulated to study the effect of the time structure of an electron linear accelerator. Results show that the total dose in several microseconds is a better indicator reflecting the radiolytic oxygen consumption rate than the dose rate. The initial oxygen greatly affects the oxygen consumption rate because of the reaction competition. The diffusion of oxygen determined by the physiological parameters is the key factor affecting oxygen depletion during the radiation using electron linear accelerators. Our code provides an efficient tool for simulating water radiolysis in different conditions
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5
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Smith M, Pimblott SM, LaVerne JA. Hydroxyl radical yields in the heavy ion radiolysis of water. Radiat Phys Chem Oxf Engl 1993 2021. [DOI: 10.1016/j.radphyschem.2021.109629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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6
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Prasselsperger A, Coughlan M, Breslin N, Yeung M, Arthur C, Donnelly H, White S, Afshari M, Speicher M, Yang R, Villagomez-Bernabe B, Currell FJ, Schreiber J, Dromey B. Real-Time Electron Solvation Induced by Bursts of Laser-Accelerated Protons in Liquid Water. PHYSICAL REVIEW LETTERS 2021; 127:186001. [PMID: 34767414 DOI: 10.1103/physrevlett.127.186001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 09/24/2021] [Indexed: 06/13/2023]
Abstract
Understanding the mechanisms of proton energy deposition in matter and subsequent damage formation is fundamental to radiation science. Here we exploit the picosecond (10^{-12} s) resolution of laser-driven accelerators to track ultrafast solvation dynamics for electrons due to proton radiolysis in liquid water (H_{2}O). Comparing these results with modeling that assumes initial conditions similar to those found in photolysis reveals that solvation time due to protons is extended by >20 ps. Supported by magnetohydrodynamic theory this indicates a highly dynamic phase in the immediate aftermath of the proton interaction that is not accounted for in current models.
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Affiliation(s)
- A Prasselsperger
- Fakultät für Physik, Ludwig-Maximilians-Universität München, 85748 Garching, Germany
- Centre for Plasma Physics, School of Mathematics and Physics, Queens University Belfast, Belfast BT7 1NN, United Kingdom
| | - M Coughlan
- Centre for Plasma Physics, School of Mathematics and Physics, Queens University Belfast, Belfast BT7 1NN, United Kingdom
| | - N Breslin
- Centre for Plasma Physics, School of Mathematics and Physics, Queens University Belfast, Belfast BT7 1NN, United Kingdom
| | - M Yeung
- Centre for Plasma Physics, School of Mathematics and Physics, Queens University Belfast, Belfast BT7 1NN, United Kingdom
| | - C Arthur
- Centre for Plasma Physics, School of Mathematics and Physics, Queens University Belfast, Belfast BT7 1NN, United Kingdom
| | - H Donnelly
- Centre for Plasma Physics, School of Mathematics and Physics, Queens University Belfast, Belfast BT7 1NN, United Kingdom
| | - S White
- Centre for Plasma Physics, School of Mathematics and Physics, Queens University Belfast, Belfast BT7 1NN, United Kingdom
| | - M Afshari
- Centre for Plasma Physics, School of Mathematics and Physics, Queens University Belfast, Belfast BT7 1NN, United Kingdom
| | - M Speicher
- Fakultät für Physik, Ludwig-Maximilians-Universität München, 85748 Garching, Germany
| | - R Yang
- Fakultät für Physik, Ludwig-Maximilians-Universität München, 85748 Garching, Germany
| | - B Villagomez-Bernabe
- The Dalton Cumbria Facility and the School of Chemistry, The University of Manchester, Oxford Rd, Manchester M13 9PL, United Kingdom
| | - F J Currell
- The Dalton Cumbria Facility and the School of Chemistry, The University of Manchester, Oxford Rd, Manchester M13 9PL, United Kingdom
| | - J Schreiber
- Fakultät für Physik, Ludwig-Maximilians-Universität München, 85748 Garching, Germany
| | - B Dromey
- Centre for Plasma Physics, School of Mathematics and Physics, Queens University Belfast, Belfast BT7 1NN, United Kingdom
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A self-referenced in-situ arrival time monitor for X-ray free-electron lasers. Sci Rep 2021; 11:3562. [PMID: 33574378 PMCID: PMC7878505 DOI: 10.1038/s41598-021-82597-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Accepted: 01/21/2021] [Indexed: 11/30/2022] Open
Abstract
We present a novel, highly versatile, and self-referenced arrival time monitor for measuring the femtosecond time delay between a hard X-ray pulse from a free-electron laser and an optical laser pulse, measured directly on the same sample used for pump-probe experiments. Two chirped and picosecond long optical supercontinuum pulses traverse the sample with a mutually fixed time delay of 970 fs, while a femtosecond X-ray pulse arrives at an instant in between both pulses. Behind the sample the supercontinuum pulses are temporally overlapped to yield near-perfect destructive interference in the absence of the X-ray pulse. Stimulation of the sample with an X-ray pulse delivers non-zero contributions at certain optical wavelengths, which serve as a measure of the relative arrival time of the X-ray pulse with an accuracy of better than 25 fs. We find an excellent agreement of our monitor with the existing timing diagnostics at the SACLA XFEL with a Pearson correlation value of 0.98. We demonstrate a high sensitivity to measure X-ray pulses with pulse energies as low as 30 \documentclass[12pt]{minimal}
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\begin{document}$$\upmu $$\end{document}μJ. Using a free-flowing liquid jet as interaction sample ensures the full replacement of the sample volume for each X-ray/optical event, thus enabling its utility even at MHz repetition rate XFEL sources.
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8
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Abstract
Historically, the field of radiation chemistry began shortly after the discovery of radioactivity, and its development has been closely related to discoveries in other related fields such as radiation and nuclear physics. Radiolysis of water and radiation chemistry have been very important in elucidating how radiation affects living matter and how it induces DNA damage. Nowadays, we recognize the importance of chemistry to understanding the effects of radiation on cells; however, it took several decades to obtain this insight, and much is still unknown. The radiolysis of water and aqueous solutions have been the subject of much experimental and theoretical research for many decades. One important concept closely related to radiation chemistry is radiation track structure. Track structure results from early physical and physicochemical events that lead to a highly non-homogenous distribution of radiolytic species. Because ionizing radiation creates unstable species that are distributed non-homogenously, the use of conventional reaction kinetics methods does not describe this chemistry well. In recent years, several methods have been developed for simulating radiation chemistry. In this review, we give a brief history of the field and the development of the simulation codes. We review the current methods used to simulate radiolysis of water and radiation chemistry, and we describe several radiation chemistry codes and their applications.
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Affiliation(s)
- Ianik Plante
- KBR, 2400 NASA Parkway, Houston, TX 77058, United States of America
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9
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Ramos-Méndez J, Shin WG, Karamitros M, Domínguez-Kondo J, Tran NH, Incerti S, Villagrasa C, Perrot Y, Štěpán V, Okada S, Moreno-Barbosa E, Faddegon B. Independent reaction times method in Geant4-DNA: Implementation and performance. Med Phys 2020; 47:5919-5930. [PMID: 32970844 DOI: 10.1002/mp.14490] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 09/07/2020] [Accepted: 09/13/2020] [Indexed: 11/10/2022] Open
Abstract
PURPOSE The simulation of individual particle tracks and the chemical stage following water radiolysis in biological tissue is an effective means of improving our knowledge of the physico-chemical contribution to the biological effect of ionizing radiation. However, the step-by-step simulation of the reaction kinetics of radiolytic species is the most time-consuming task in Monte Carlo track-structure simulations, with long simulation times that are an impediment to research. In this work, we present the implementation of the independent reaction times (IRT) method in Geant4-DNA Monte Carlo toolkit to improve the computational efficiency of calculating G-values, defined as the number of chemical species created or lost per 100 eV of deposited energy. METHODS The computational efficiency of IRT, as implemented, is compared to that from available Geant4-DNA step-by-step simulations for electrons, protons and alpha particles covering a wide range of linear energy transfer (LET). The accuracy of both methods is verified using published measured data from fast electron irradiations for • OH and e aq - for time-dependent G-values. For IRT, simulations in the presence of scavengers irradiated by cobalt-60 γ-ray and 2 MeV protons are compared with measured data for different scavenging capacities. In addition, a qualitative assessment comparing measured LET-dependent G-values with Geant4-DNA calculations in pure liquid water is presented. RESULTS The IRT improved the computational efficiency by three orders of magnitude relative to the step-by-step method while differences in G-values by 3.9% at 1 μs were found. At 7 ps, • OH and e aq - yields calculated with IRT differed from recent published measured data by 5% ± 4% and 2% ± 4%, respectively. At 1 μs, differences were 9% ± 5% and 6% ± 7% for • OH and e aq - , respectively. Uncertainties are one standard deviation. Finally, G-values at different scavenging capacities and LET-dependent G-values reproduced the behavior of measurements for all radiation qualities. CONCLUSION The comprehensive validation of the Geant4-DNA capabilities to accurately simulate the chemistry following water radiolysis is an ongoing work. The implementation presented in this work is a necessary step to facilitate performing such a task.
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Affiliation(s)
- José Ramos-Méndez
- Department of Radiation Oncology, University of California San Francisco, San Francisco, CA, 94115, USA
| | - Wook-Geun Shin
- Centre d'Études Nucléaires de Bordeaux Gradignan, Université de Bordeaux, CNRS/IN2P3, UMR5797, Gradignan, 33175, France.,Department of Radiation Convergence Engineering, Yonsei University, Wonju, 26493, Korea
| | - Mathieu Karamitros
- Radiation Laboratory, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Jorge Domínguez-Kondo
- Facultad de Ciencias Físico Matemáticas, Benemérita Universidad Autónoma de Puebla, Puebla PUE, 72000, Mexico
| | - Ngoc Hoang Tran
- Centre d'Études Nucléaires de Bordeaux Gradignan, Université de Bordeaux, CNRS/IN2P3, UMR5797, Gradignan, 33175, France
| | - Sebastien Incerti
- Centre d'Études Nucléaires de Bordeaux Gradignan, Université de Bordeaux, CNRS/IN2P3, UMR5797, Gradignan, 33175, France
| | - Carmen Villagrasa
- Institut de Radioprotection et de Sûreté Nucléaire, IRSN, BP17, Fontenay-aux-Roses, 92262, France
| | - Yann Perrot
- Institut de Radioprotection et de Sûreté Nucléaire, IRSN, BP17, Fontenay-aux-Roses, 92262, France
| | - Václav Štěpán
- Department of Radiation Dosimetry, Nuclear Physics Institute of the CAS, Prague, Czech Republic
| | - Shogo Okada
- KEK, 1-1, Oho, Tsukuba, Ibaraki, 305-0801, Japan
| | - Eduardo Moreno-Barbosa
- Facultad de Ciencias Físico Matemáticas, Benemérita Universidad Autónoma de Puebla, Puebla PUE, 72000, Mexico
| | - Bruce Faddegon
- Department of Radiation Oncology, University of California San Francisco, San Francisco, CA, 94115, USA
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10
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Ramos-Méndez J, Domínguez-Kondo N, Schuemann J, McNamara A, Moreno-Barbosa E, Faddegon B. LET-Dependent Intertrack Yields in Proton Irradiation at Ultra-High Dose Rates Relevant for FLASH Therapy. Radiat Res 2020; 194:351-362. [PMID: 32857855 PMCID: PMC7644138 DOI: 10.1667/rade-20-00084.1] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 07/13/2020] [Indexed: 01/01/2023]
Abstract
FLASH radiotherapy delivers a high dose (≥10 Gy) at a high rate (≥40 Gy/s). In this way, particles are delivered in pulses as short as a few nanoseconds. At that rate, intertrack reactions between chemical species produced within the same pulse may affect the heterogeneous chemistry stage of water radiolysis. This stochastic process suits the capabilities of the Monte Carlo method, which can model intertrack effects to aid in radiobiology research, including the design and interpretation of experiments. In this work, the TOPAS-nBio Monte Carlo track-structure code was expanded to allow simulations of intertrack effects in the chemical stage of water radiolysis. Simulation of the behavior of radiolytic yields over a long period of time (up to 50 s) was verified by simulating radiolysis in a Fricke dosimeter irradiated by 60Co γ rays. In addition, LET-dependent G values of protons delivered in single squared pulses of widths, 1 ns, 1 µs and 10 µs, were obtained and compared to simulations using no intertrack considerations. The Fricke simulation for the calculated G value of Fe3+ ion at 50 s was within 0.4% of the accepted value from ICRU Report 34. For LET-dependent G values at the end of the chemical stage, intertrack effects were significant at LET values below 2 keV/µm. Above 2 keV/µm the reaction kinetics remained limited locally within each track and thus, effects of intertrack reactions remained low. Therefore, when track structure simulations are used to investigate the biological damage of FLASH irradiation, these intertrack reactions should be considered. The TOPAS-nBio framework with the expansion to intertrack chemistry simulation provides a useful tool to assist in this task.
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Affiliation(s)
- J. Ramos-Méndez
- Department of Radiation Oncology, University of California San Francisco, San Francisco, California
| | - N. Domínguez-Kondo
- Facultad de Ciencias Físico-Matemáticas, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico
| | - J. Schuemann
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - A. McNamara
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - E. Moreno-Barbosa
- Facultad de Ciencias Físico-Matemáticas, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico
| | - Bruce Faddegon
- Department of Radiation Oncology, University of California San Francisco, San Francisco, California
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11
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Delgado HE, Elg DT, Bartels DM, Rumbach P, Go DB. Chemical Analysis of Secondary Electron Emission from a Water Cathode at the Interface with a Nonthermal Plasma. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:1156-1164. [PMID: 31995383 DOI: 10.1021/acs.langmuir.9b03654] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
When a nonthermal plasma and a liquid form part of the same circuit, the liquid may function as a cathode, in which case electrons are emitted from the liquid into the gas to sustain the plasma. As opposed to solid electrodes, the mechanism of this emission has not been established for a liquid, even though various theories have attempted to explain it via chemical processes in the liquid phase. In this work, we tested the effects of the interfacial chemistry on electron emission from water, including the role of pH as well as the hydroxyl radical, the hydrogen atom, the solvated electron, and the presolvated electron; it was found that none of these species are critical to sustain the plasma. We propose an emission mechanism where electrons, generated from ionized water molecules in the uppermost monolayers of solution, are emitted into the plasma directly from the conduction band of the water.
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Affiliation(s)
- Hernan E Delgado
- Department of Chemical and Biomolecular Engineering , University of Notre Dame , Notre Dame , Indiana 46556 , United States
| | - Daniel T Elg
- Department of Engineering , University of Southern Indiana , Evansville , Indiana 47712 , United States
| | - David M Bartels
- Radiation Laboratory and Department of Chemistry and Biochemistry, Notre Dame Radiation Laboratory , University of Notre Dame , Notre Dame , Indiana 46556 , United States
| | - Paul Rumbach
- Department of Aerospace and Mechanical Engineering , University of Notre Dame , Notre Dame , Indiana 46556 , United States
| | - David B Go
- Department of Chemical and Biomolecular Engineering , University of Notre Dame , Notre Dame , Indiana 46556 , United States
- Department of Aerospace and Mechanical Engineering , University of Notre Dame , Notre Dame , Indiana 46556 , United States
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12
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Šefl M, Pachnerová Brabcová K, Štěpán V. Dosimetry as a Catch in Radiobiology Experiments. Radiat Res 2018; 190:404-411. [PMID: 30016217 DOI: 10.1667/rr15020.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Experimental radiobiological studies in which the effects of ionizing radiation on a biological model are examined often highlight the biological aspects while missing detailed descriptions of the geometry, sample and dosimetric methods used. Such omissions can hinder the reproducibility and comparability of the experimental data. An application based on the Geant4 simulation toolkit was developed to design experiments using a biological solution placed in a microtube. The application was used to demonstrate the influence of the type of microtube, sample volume and energy of a proton source on the dose distribution across the sample, and on the mean dose in the whole sample. The results shown here are for samples represented by liquid water in the 0.4-, 1.5- and 2.0-ml microtubes irradiated with 20, 30 and 100 MeV proton beams. The results of this work demonstrate that the mean dose and homogeneity of the dose distribution within the sample strongly depend on all three parameters. Furthermore, this work shows how the dose uncertainty propagates into the scored primary DNA damages in plasmid DNA studies using agarose gel electrophoresis. This application is provided freely to assist users in verifying their experimental setup prior to the experiment.
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Affiliation(s)
- Martin Šefl
- a Nuclear Physics Institute of the Czech Academy of Sciences, Prague, Czech Republic.,b Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague, Prague, Czech Republic
| | | | - Václav Štěpán
- a Nuclear Physics Institute of the Czech Academy of Sciences, Prague, Czech Republic
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Boscolo D, Krämer M, Durante M, Fuss M, Scifoni E. TRAX-CHEM: A pre-chemical and chemical stage extension of the particle track structure code TRAX in water targets. Chem Phys Lett 2018. [DOI: 10.1016/j.cplett.2018.02.051] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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14
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15
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Horne GP, Pimblott SM, LaVerne JA. Inhibition of Radiolytic Molecular Hydrogen Formation by Quenching of Excited State Water. J Phys Chem B 2017; 121:5385-5390. [PMID: 28492328 DOI: 10.1021/acs.jpcb.7b02775] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Comparison of experimental measurements of the yield of molecular hydrogen produced in the gamma radiolysis of water and aqueous nitrate solutions with predictions of a Monte Carlo track chemistry model shows that the nitrate anion scavenging of the hydrated electron, its precursor, and hydrogen atom cannot account for the observed decrease in the yield at high nitrate anion concentrations. Inclusion of the quenching of excited states of water (formed by either direct excitation or reaction of the water radical cation with the precursor to the hydrated electron) by the nitrate anion into the reaction scheme provides excellent agreement between the stochastic calculations and experiment demonstrating the existence of this short-lived species and its importance in water radiolysis. Energy transfer from the excited states of water to the nitrate anion producing an excited state provides an additional pathway for the production of nitrogen containing products not accounted for in traditional radiation chemistry scenarios. Such reactions are of central importance in predicting the behavior of liquors common in the reprocessing of spent nuclear fuel and the storage of highly radioactive liquid waste prior to vitrification.
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Affiliation(s)
- Gregory P Horne
- California State University at Long Beach , Long Beach, California 90804, United States.,Radiation Laboratory, University of Notre Dame , Notre Dame, Indiana 46556, United States
| | - Simon M Pimblott
- Dalton Cumbrian Facility, The University of Manchester , Westlakes Science and Technology Park, Cumbria CA24 3HA, U.K.,School of Chemistry, The University of Manchester , Oxford Road, Manchester M13 9PL, U.K
| | - Jay A LaVerne
- Radiation Laboratory, University of Notre Dame , Notre Dame, Indiana 46556, United States.,Department of Physics, University of Notre Dame , Notre Dame, Indiana 46556, United States
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16
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Gu Y, Dong W, Luo C, Liu T. Efficient Reductive Decomposition of Perfluorooctanesulfonate in a High Photon Flux UV/Sulfite System. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:10554-10561. [PMID: 27607769 DOI: 10.1021/acs.est.6b03261] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Hydrated electron (eaq-) induced reduction techniques are promising for decomposing recalcitrant organic pollutants. However, its vigorous reactivity with copresent scavenging species and the difficulty in minimizing the competitive reactions make the proportion of eaq- participating in pollutant decomposition low, reflecting by slow decomposition kinetics. In this study, a high photon flux UV/sulfite system was employed to promote eaq- production. Its feasibility in enhancing a notorious recalcitrant pollutant, PFOS, decomposition was investigated. The effective photon flux utilized for producing eaq- was 9.93 × 10-8 einstein/cm2·s. At initial solution pH 9.2, with DO about 5 mg/L, and at around 25 °C, 98% PFOS was decomposed within 30 min from its initial concentration of 32 μM. The kobs of PFOS decomposition was 0.118 min-1 (7.08 h-1), and about 8-400 folds faster than those obtained in other reductive approaches. In this system, PFOS decomposition showed can tolerate copresent 7 mg N/L of NO3-. Suggested by molecular orbitals and thermodynamic analyses, the mechanisms responsible for PFOS decomposition involve defluorination, desulfonation, and centermost C-C bond scission. By demonstrating a more practical relevant treatment process, the outcomes of this study would be helpful for facilitating future applications of eaq- induced reduction techniques for efficient recalcitrant pollutants decomposition.
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Affiliation(s)
- Yurong Gu
- Harbin Institute of Technology Shenzhen Graduate School, Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control, Shenzhen 518055, P. R. China
| | - Wenyi Dong
- Harbin Institute of Technology Shenzhen Graduate School, Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control, Shenzhen 518055, P. R. China
| | - Cheng Luo
- Harbin Institute of Technology Shenzhen Graduate School, Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control, Shenzhen 518055, P. R. China
| | - Tongzhou Liu
- Harbin Institute of Technology Shenzhen Graduate School, Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control, Shenzhen 518055, P. R. China
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Butarbutar SL, Meesungnoen J, Guzonas DA, Stuart CR, Jay-Gerin JP. Modeling the Radiolysis of Supercritical Water by Fast Neutrons: Density Dependence of the Yields of Primary Species at 400°C. Radiat Res 2014; 182:695-704. [DOI: 10.1667/rr13715.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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18
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Differences in fundamental reaction mechanisms between high and low-LET in recent advancements and applications of ionizing radiation. Radiat Phys Chem Oxf Engl 1993 2014. [DOI: 10.1016/j.radphyschem.2014.05.032] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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19
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Dynamics of low-energy electrons in liquid water with consideration of Coulomb interaction with positively charged water molecules induced by electron collision. Radiat Phys Chem Oxf Engl 1993 2014. [DOI: 10.1016/j.radphyschem.2014.04.017] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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20
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Balcerzyk A, Baldacchino G. Implementation of laser induced fluorescence in a pulse radiolysis experiment – a new way to analyze resazurin-like reduction mechanisms. Analyst 2014; 139:1707-12. [DOI: 10.1039/c3an02000b] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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21
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Friedland W, Dingfelder M, Kundrát P, Jacob P. Track structures, DNA targets and radiation effects in the biophysical Monte Carlo simulation code PARTRAC. Mutat Res 2011; 711:28-40. [PMID: 21281649 DOI: 10.1016/j.mrfmmm.2011.01.003] [Citation(s) in RCA: 236] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2010] [Revised: 01/18/2011] [Accepted: 01/22/2011] [Indexed: 01/08/2023]
Abstract
This review describes the PARTRAC suite of comprehensive Monte Carlo simulation tools for calculations of track structures of a variety of ionizing radiation qualities and their biological effects. A multi-scale target model characterizes essential structures of the whole genomic DNA within human fibroblasts and lymphocytes in atomic resolution. Calculation methods and essential results are recapitulated regarding the physical, physico-chemical and chemical stage of track structure development of radiation damage induction. Recent model extension towards DNA repair processes extends the time dimension by about 12 orders of magnitude and paves the way for superior predictions of radiation risks.
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Affiliation(s)
- Werner Friedland
- Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Radiation Protection, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany.
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Tsoi M, Do TT, Tang V, Aguilera JA, Perry CC, Milligan JR. Characterization of condensed plasmid DNA models for studying the direct effect of ionizing radiation. Biophys Chem 2010; 147:104-10. [PMID: 20096988 DOI: 10.1016/j.bpc.2009.12.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2009] [Revised: 12/19/2009] [Accepted: 12/19/2009] [Indexed: 10/20/2022]
Abstract
We have examined the changes in physical properties of aqueous solutions of the plasmid pUC18 that take place on the addition of the cationic oligopeptide penta-arginine. An increase in sedimentation rate and static light scattering, and changes in the nucleic acid CD spectrum all suggest that this ligand acts to condense the plasmid. Dynamic light scattering suggests the hydrodynamic radii of the condensate particles are a few micrometers, ca. 50-fold larger than that of the monomeric plasmid. Condensation of the plasmid also produces a ca. 100-fold decrease in the strand break yield produced by gamma irradiation. This extensive protection against reactive intermediates in the bulk of the solution implies that condensed plasmid DNA may offer a model system with which to study the direct effect of ionizing radiation (ionization of the DNA itself). The use of peptide ligands as condensing agents in this application is attractive because the derivatives of several amino acids (particularly tryptophan and tyrosine) have been shown to modify the radiation chemistry of DNA extensively.
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Affiliation(s)
- Mandi Tsoi
- Department of Radiology, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0610, USA
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Meesungnoen J, Jay-Gerin JP. High-LET ion radiolysis of water: oxygen production in tracks. Radiat Res 2009; 171:379-86. [PMID: 19267566 DOI: 10.1667/rr1468.1] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
It is known that molecular oxygen is a product of the radiolysis of water with high-linear energy transfer (LET) radiation, a result that is of particular significance in radiobiology and of practical relevance in radiotherapy. In fact, it has been suggested that the radiolytic formation of an oxygenated microenvironment around the tracks of high-LET heavy ions is an important factor in their enhanced biological efficiency in the sense that this may be due to an "oxygen effect" by O(2) produced by these ions in situ. Using Monte Carlo track simulations of pure, deaerated water radiolysis by 4.8 MeV (4)He(2+) (LET approximately 94 keV/microm) and 24 MeV (12)C(6+) (LET approximately 490 keV/microm) ions, including the mechanism of multiple ionization of water, we have calculated the yields and concentrations of O(2) in the tracks of these irradiating ions as a function of time between approximately 10(-12) and 10(-5) s at 25 and 37 degrees C. The track oxygen concentrations obtained compare very well with O(2) concentrations estimated from the "effective" amounts of oxygen that are needed to produce the observed reduction in oxygen enhancement ratio (OER) with LET (assuming this decrease is attributable to the sole radiolytic formation of O(2) in the tracks). For example, for 24 MeV (12)C(6+) ions, the initial track concentration of O(2) is estimated to be more than three orders of magnitude higher than the oxygen levels present in normally oxygenated and hypoxic tumor regions as well as in normal human cells. Such results, which largely plead in favor of the "oxygen in the heavy-ion track" hypothesis, could explain at least in part the greater efficiency of high-LET radiation for cell inactivation (at equal radiation dose).
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Affiliation(s)
- Jintana Meesungnoen
- Département de Médecine Nucléaire et de Radiobiologie, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke (Québec) J1H 5N4, Canada
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Atinault E, De Waele V, Fattahi M, LaVerne JA, Pimblott SM, Mostafavi M. Aqueous solution of UCl6(2-) in O2 saturated acidic medium: an efficient system to scavenge all primary radicals in spurs produced by irradiation. J Phys Chem A 2009; 113:949-51. [PMID: 19159206 DOI: 10.1021/jp810579x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Absorbance measurements find the yield of the oxidation of U(IV) to be (8.75 +/- 0.05) x 10(-7) mol J(-1) in the (60)Co gamma radiolysis of aqueous solutions containing 4.4 x 10(-3) mol L(-1) U(IV) in the presence of O(2) saturated 2 mol L(-1) Cl(-) at pH = 0. This high value of oxidation yield suggests that all primary radicals formed by water decomposition are scavenged in these solutions. Simulations using a nonhomogeneous stochastic kinetic track model agree with the experimental results and are used to explain the mechanism for scavenging radicals and oxidation of U(IV).
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Yamashita S, Katsumura Y, Lin M, Muroya Y, Miyazaki T, Murakami T, Meesungnoen J, Jay-Gerin JP. Water Radiolysis with Heavy Ions of Energies up to 28 GeV. 3. Measurement ofG(MV·+) in Deaerated Methyl Viologen Solutions Containing Various Concentrations of Sodium Formate and Monte Carlo Simulation. Radiat Res 2008; 170:521-33. [DOI: 10.1667/rr1203.1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Yamashita S, Katsumura Y, Lin M, Muroya Y, Maeyama T, Murakami T. Water radiolysis with heavy ions of energies up to 28GeV—2: Extension of primary yield measurements to very high LET values. Radiat Phys Chem Oxf Engl 1993 2008. [DOI: 10.1016/j.radphyschem.2008.05.037] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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28
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Yamashita S, Katsumura Y, Lin M, Muroya Y, Miyazaki T, Murakami T. Water radiolysis with heavy ions of energies up to 28GeV. Radiat Phys Chem Oxf Engl 1993 2008. [DOI: 10.1016/j.radphyschem.2007.07.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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30
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Edwards EJ, Wilson PPH, Anderson MH, Mezyk SP, Pimblott SM, Bartels DM. An apparatus for the study of high temperature water radiolysis in a nuclear reactor: calibration of dose in a mixed neutron/gamma radiation field. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2007; 78:124101. [PMID: 18163737 DOI: 10.1063/1.2814167] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The cooling water of nuclear reactors undergoes radiolytic decomposition induced by gamma, fast electron, and neutron radiation in the core. To model the process, recombination reaction rates and radiolytic yields for the water radical fragments need to be measured at high temperature and pressure. Yields for the action of neutron radiation are particularly hard to determine independently because of the beta/gamma field also present in any reactor. In this paper we report the design of an apparatus intended to measure neutron radiolysis yields as a function of temperature and pressure. A new methodology for separation of neutron and beta/gamma radiolysis yields in a mixed radiation field is proposed and demonstrated.
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Affiliation(s)
- Eric J Edwards
- Department of Engineering Physics, University of Wisconsin-Madison, 1500 Engineering Drive, Madison, Wisconsin 53706, USA
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31
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Janik D, Janik I, Bartels DM. Neutron and β/γ Radiolysis of Water up to Supercritical Conditions. 1. β/γ Yields for H2, H• Atom, and Hydrated Electron. J Phys Chem A 2007; 111:7777-86. [PMID: 17645317 DOI: 10.1021/jp071751r] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Yields for H2, H(.) atom, and hydrated electron production in beta/gamma radiolysis of water have been measured from room temperature up to 400 degrees C on a 250 bar isobar, and also as a function of pressure (density) at 380 and 400 degrees C. Radiolysis was carried out using a beam of 2-3 MeV electrons from a van de Graaff accelerator, and detection was by mass spectrometer analysis of gases sparged from the irradiated water. N2O was used as a specific scavenger for hydrated electrons giving N2 as product. Ethanol-d(6) was used to scavenge H(.) atoms, giving HD as a stable product. It is found that the hydrated electron yield decreases and the H(.) atom yield increases dramatically at lower densities in supercritical water, and the overall escape yield increases. The yield of molecular H2 increases with temperature and does not tend toward zero at low density, indicating that it is formed promptly rather than in spur recombination. A minimum in both the radical and H2 yields is observed around 0.4 kg/dm(3) density in supercritical water.
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Affiliation(s)
- Dorota Janik
- Radiation Laboratory, University of Notre Dame, Notre Dame, Indiana 46556, USA
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Saeki A, Kozawa T, Ohnishi Y, Tagawa S. Reactivity between Biphenyl and Precursor of Solvated Electrons in Tetrahydrofuran Measured by Picosecond Pulse Radiolysis in Near-Ultraviolet, Visible, and Infrared. J Phys Chem A 2007; 111:1229-35. [PMID: 17256922 DOI: 10.1021/jp067520m] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The initial decrease of solvated electrons in tetrahydrofuran (THF) upon addition of biphenyl was investigated by picosecond pulse radiolysis. Transient absorption spectra derived from the biphenyl radical anion (centered at 408 and 655 nm) and solvated electrons of THF (infrared) were successfully measured in the wavelength region from 400 to 900 nm by the extension of a femtosecond continuum probe light to near-ultraviolet using a second harmonic generation of Ti:sapphire laser and a CaF2 plate. From the analysis of kinetic traces at 1300 nm considering the overlap of primary solvated electrons and partial biphenyl radical anion, C37, which is defined by the solute concentration to reduce the initial yield of solvated electrons to 1/e, was found to be 87 +/- 3 mM. The rate constant of solvated electrons with biphenyl was determined as 5.8 +/- 0.3 x 10(10) M(-1) s(-1). We demonstrate that the kinetic traces at both 408 nm mainly due to biphenyl radical anion and 1300 nm mainly due to solvated electrons are reproduced with high accuracy and consistency by a simple kinetic analysis. Much higher concentrations of biphenyl (up to 2 M) were examined, showing further increase of the initial yield of biphenyl radical anion accompanying a fast decay component. This observation is discussed in terms of geminate ion recombination, scavenging, delayed geminate ion recombination, and direct ionization of biphenyl at high concentration.
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Affiliation(s)
- Akinori Saeki
- The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan.
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