Article
Biology
Seiko Hirota, Chryzel Angelica B. Gonzales, Hiroshi Yasuda
Summary: The study found that there is a linear dose response to X-rays and gamma-rays in fingernails, with minimal impact from secondary electrons and little inter-individual variation in sensitivity. Signal intensities fluctuate in measurements depending on the sample, with an average fluctuation corresponding to 1.7 Gy and a standard deviation of 1.3 Gy.
JOURNAL OF RADIATION RESEARCH
(2021)
Article
Multidisciplinary Sciences
Juvinch R. Vicente, Amanda Durkin, Kristina Shrestha, Mihaela Balu
Summary: Melanin plays a significant role in skin homeostasis and protection. The two-photon excited fluorescence lifetime detection method allows for selective and quantitative measurement of melanin. Previous studies lacked consideration of skin heterogeneity due to limited field of view. In this work, a fast large-area multiphoton exoscope was used to evaluate the 3D distribution of epidermal melanin content, improving measurement reliability.
SCIENTIFIC REPORTS
(2022)
Article
Chemistry, Multidisciplinary
Toshinobu Nakajo, Jun Kumagai, Shinpei Kusaka, Akihiro Hori, Yuh Hijikata, Jenny Pirillo, Yunsheng Ma, Ryotaro Matsuda
Summary: Triplet carbenes (TCs) are highly reactive species with unique electronic states, making it challenging to balance reactivity and stability. By confining TCs in the nanospace of a metal-organic framework (MOF), it is possible to enhance their thermal stability while maintaining reactivity, allowing for the stabilization of highly reactive species.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Biochemistry & Molecular Biology
Lionel Mignion, Celine M. Desmet, Evelyne Harkemanne, Isabelle Tromme, Nicolas Joudiou, Mohammad Wehbi, Jean-Francois Baurain, Bernard Gallez
Summary: This study explored the capability of low-frequency Electron Paramagnetic Resonance (EPR) to detect melanin in the human skin. The results showed that EPR could differentiate the EPR signal of melanin between melanoma and benign nevi, providing a new method for the diagnosis of pigmented skin lesions.
FREE RADICAL BIOLOGY AND MEDICINE
(2022)
Article
Chemistry, Inorganic & Nuclear
Molly M. Lockart, Kyle C. Edwards, John B. Vincent, Brad S. Pierce
Summary: The study detected an EPR signal for Mn(III) bound to transferrin, suggesting the six-coordinate nature of the Mn(III) centers in an elongated tetragonal environment. Incorporation of Mn(III) within the Tf active site did not significantly alter the coordination number or active site geometry compared to native Fe(III)(2)-Tf. The parallel mode EPR signal for Mn(III)(2)-Tf could be valuable for future studies on the physiological relevance of Mn(III)(2)-Tf.
Article
Chemistry, Analytical
Hideo Utsumi, Toshiki Masumizu, Ryoma Kobayashi, Tomoko Tahira, Fuminori Hyodo, Tatsuya Shimizu, Tatsuya Naganuma, Kazunori Anzai
Summary: Free radicals are key substances in organisms but can also cause oxidative diseases. Dynamic nuclear polarization- magnetic resonance imaging is a noninvasive imaging method that can be used for in vivo free radical imaging.
ANALYTICAL CHEMISTRY
(2021)
Article
Agricultural Engineering
Dongmei Bi, Mengqian Yin, Fupeng Huang, Jiawen Zhang, Weiming Yi
Summary: The evolution mechanism of EPFRs in three-component pyrolytic carbon was characterized using EPR spectroscopy. The types of EPFRs changed with increasing pyrolysis temperature, shifting from oxygen-containing free radicals to aromatic ring and polymeric aromatic radicals. The interaction between the three components did not significantly affect the concentration of EPFRs. This study provides guidance for the generation and regulation of EPFRs in biochar.
INDUSTRIAL CROPS AND PRODUCTS
(2023)
Article
Chemistry, Inorganic & Nuclear
Anthony J. Campanella, Manh-Thuong Nguyen, Jun Zhang, Thacien Ngendahimana, William E. Antholine, Gareth R. Eaton, Sandra S. Eaton, Vassiliki-Alexandra Glezakou, Joseph M. Zadrozny
Summary: This work investigates how variations in ligand structures affect the EPR spectroscopic properties of five Cr(III) complexes, indicating that the spectral broadening is correlated to rigidity in the inner coordination sphere and reflected in ligand-dependent distribution of Cr-N bond distances.
DALTON TRANSACTIONS
(2021)
Article
Chemistry, Multidisciplinary
Santina S. Cruz, Vadim Tanygin, Benjamin J. Lear
Summary: Using electron spin resonance spectroscopy, it has been demonstrated that morphological asymmetries in small spheroidal metallic nanoparticles significantly affect the electronic behavior of states near the metal's Fermi energy. The study found that morphological effects were more important than size distributions in explaining the asymmetry in electronic behavior, and this was consistent across various particles made from different metals. Additionally, the study also showed that morphological changes can tune the electronic properties of even small particles, as evidenced by the modeling used to explain asymmetries in both electron spin resonance spectra and plasmon spectra.
Article
Materials Science, Multidisciplinary
S. A. Rodriguez, S. S. Gomez, J. Fernandez-Rossier, A. Ferron
Summary: Electron-spin resonance carried out with scanning tunneling microscopes (ESR-STM) is a recently developed experimental technique that is attracting enormous interest on account of its potential to carry out single-spin on-surface resonance with subatomic resolution. In this theoretical study, we investigate the role of tip-adatom interactions in order to optimize spin resonance measurements. We provide guidelines for optimizing the tip-sample distance to cancel the effective magnetic field created by the tip on the surface spin, for reducing the voltage dependence of the surface-spin resonance frequency, and for inferring the detuning angle between the applied field and the tip magnetization.
Article
Physics, Atomic, Molecular & Chemical
Nicolas Tkatchenko, Alexander Romanyukha, Ricardo Reyes, Steven G. Swarts, Didier Gourier, Francois Trompier
Summary: Human nails have been studied for their potential use in dosimetry using EPR signals induced by ionizing radiation. However, no fully validated protocol for retrospective dose measurement has been developed. The complexity of the EPR spectrum and the overlap between radiation-induced signals and background signals pose a major challenge. Detailed characterization of background signals is required to measure the radiation-induced signals accurately.
APPLIED MAGNETIC RESONANCE
(2022)
Article
Chemistry, Multidisciplinary
Muralidharan Shanmugam, Mussa Quareshy, Alexander D. Cameron, Timothy D. H. Bugg, Yin Chen
Summary: The oxidation of quaternary ammonium substrate, carnitine, by non-heme iron-containing Acinetobacter baumannii (Ab) oxygenase CntA/reductase CntB is associated with cardiovascular disease. A study using blue-light activation of NADH coupled with EPR measurements revealed that electron transfer from NADH to the oxidized [2Fe-2S] cluster in AbCntA only occurs in the presence of carnitine. The AbCntA-E205A mutant showed severely affected electron transfer, leading to a significant loss of catalytic activity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Physics, Applied
T. D. Gustafson, N. C. Giles, B. C. Holloway, C. A. Lenyk, J. Jesenovec, J. S. McCloy, M. D. McCluskey, L. E. Halliburton
Summary: In this study, electron paramagnetic resonance (EPR) and optical absorption were used to characterize Cu2+ and Cu3+ ions in Cu-doped beta-Ga2O3. Different EPR spectra and optical absorption bands were observed for Cu2+ and Cu3+ ions. The results showed that Cu2+(A) ions occupy defect-free octahedral Ga sites, while Cu2+(B) ions have adjacent defects, possibly OH- ions, oxygen vacancies, or H- ions trapped within oxygen vacancies. Additionally, exposure of the crystals to 275 nm light at room temperature produced Cu3+ ions and reduced the number of Cu2+(A) and Cu2+(B) ions. Thermal annealing studies showed that Cu3+ ions decay, and Cu2+ ions recover.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Chemistry, Physical
Constantinos Moularas, Pavlos Psathas, Yiannis Deligiannakis
Summary: The study utilizes electron paramagnetic resonance to distinguish the characteristics of photo-generated carriers in 14 nm and 26 nm NaTaO3 particles. The 14 nm particles exhibit higher photoinduced carrier yield, while the 26 nm particles show lower photoinduced carrier yield.
CHEMICAL PHYSICS LETTERS
(2021)
Article
Chemistry, Applied
Biyang Zhu, Dongxiao Sun-Waterhouse, Lijun You
Summary: The UV/H2O2 process is being increasingly used in the degradation of carbohydrates, but the mechanisms involved are still unclear. This study aimed to fill this knowledge gap by investigating the mechanisms and energy consumption in the hydroxyl radical-mediated degradation of xylooligosaccharides (XOSs) in the UV/H2O2 system. The results showed that UV photolysis of H2O2 produced a significant amount of hydroxyl radicals, and the degradation of XOSs followed a pseudo-first-order model. Xylobiose and xylotriose were more susceptible to attack by hydroxyl radicals, and their hydroxyl groups were converted to carbonyl groups and then carboxy groups.
CARBOHYDRATE POLYMERS
(2023)
Article
Nuclear Science & Technology
A. I. Ivannikov, A. M. Khailov, S. P. Orlenko, V. F. Stepanenko, F. Trompier, K. Sh Zhumadilov
Summary: The EPR spectra of alanine dosimeters irradiated by gamma-rays and alpha-particles were analyzed to differentiate their contributions in a mixed radiation field, which may be useful for controlling dose in experiments involving neutron boron capture therapy. Different components were observed for gamma and alpha-irradiated alanine, allowing for discrimination in the mixed radiation field.
RADIATION MEASUREMENTS
(2021)
Article
Physics, Atomic, Molecular & Chemical
Nicolas Tkatchenko, Alexander Romanyukha, Ricardo Reyes, Steven G. Swarts, Didier Gourier, Francois Trompier
Summary: Human nails have been studied for their potential use in dosimetry using EPR signals induced by ionizing radiation. However, no fully validated protocol for retrospective dose measurement has been developed. The complexity of the EPR spectrum and the overlap between radiation-induced signals and background signals pose a major challenge. Detailed characterization of background signals is required to measure the radiation-induced signals accurately.
APPLIED MAGNETIC RESONANCE
(2022)
Editorial Material
Biology
Harold M. Swartz, Ruth C. Wilkins, Elizabeth Ainsbury, Matthias Port, Ann Barry Flood, Francois Trompier, Laurence Roy, Steven G. Swarts
INTERNATIONAL JOURNAL OF RADIATION BIOLOGY
(2022)
Article
Chemistry, Physical
Oswaldo Baffa, Patricia Nicolucci, Marcos Candeias, Francois Trompier, Angela Kinoshita
Summary: This study used alanine/electron spin resonance dosimetry to assess photon doses to electronic equipment and cables at the Angra 1 nuclear power plant in Brazil during an operation cycle. The influence of neutron radiation was also evaluated, and the results showed that alanine dosimetry is capable of operating over a wide dose range. The study suggests that alanine/ESR dosimetry can be used as part of the Environmental Qualification Program of Electrical Equipment in a nuclear power plant.
RADIATION PHYSICS AND CHEMISTRY
(2022)
Article
Geography, Physical
Davinia Moreno, Ana Isabel Ortega, Christophe Falgueres, Qingfeng Shao, Olivier Tombret, Asier Gomez-Olivencia, Arantza Aranburu, Francois Trompier, Jose Maria Bermudez de Castro, Eudald Carbonell, Juan Luis Arsuaga
Summary: The Galeria de las Estatuas is a Mousterian site located in the karstic system of Sierra de Atapuerca, Spain. It has yielded a large number of lithic artefacts, faunal remains, Neanderthal foot phalanx, and mitochondrial and nuclear DNA. With various dating methods, the site has been dated to approximately 45ka cal BP, and the sediment containing Mousterian lithic artefacts, faunal, and human remains is estimated to have been deposited during the second part of MIS5.
QUATERNARY GEOCHRONOLOGY
(2022)
Article
Radiology, Nuclear Medicine & Medical Imaging
A. M. M. Leite, M. Cavallone, M. G. Ronga, F. Trompier, Y. Ristic, A. Patriarca, L. De Marzi
Summary: To assess the suitability of standard clinical dosimeters, the ion collection efficiency of several commercially available air-vented ionization chambers (IC) was evaluated in both conventional and very-high dose rate (VHDR) proton irradiation conditions. The results showed that the ion recombination correction factors for most detectors were below 2% at VHDRs, indicating comparable collection efficiency to conventional dose rates. However, the Nano Razor exhibited higher recombination correction factors at VHDRs, suggesting a reduction in collection efficiency at higher dose rates.
PHYSICA MEDICA-EUROPEAN JOURNAL OF MEDICAL PHYSICS
(2023)
Article
Physiology
Manon Guillou, Bruno L'Homme, Francois Trompier, Gaetan Gruel, Yolanda Prezado, Morgane Dos Santos
Summary: Interventional radiology has become an essential tool for treatment or diagnosis, but the lack of knowledge about the radiobiological consequences of low-energy X-rays used in these practices has led to uncertainties in prognosis. In order to improve radiation protection and predict complications, a new preclinical mouse model was implemented to mimic radiological burn in interventional radiology. Experimental and Monte Carlo simulation methods were used to characterize the dose deposition in different tissues. The results showed the heterogeneity of dose deposition and the influence of tissue density on the characteristics of secondary electrons.
FRONTIERS IN PHYSIOLOGY
(2022)
Article
Physics, Multidisciplinary
Paola Fattibene, Francois Trompier, Celine Bassinet, Bartlomiej Ciesielski, Michael Discher, Jonathan Eakins, Chryzel Angelica B. Gonzales, Christelle Huet, Alexander Romanyukha, Clemens Woda, Malgorzata Juniewicz, Hyoungtaek Kim, Jungil Lee, Agnieszka Marciniak, Sergey Sholom, Hiroshi Yasuda
Summary: This article aims to provide an overview of the questions, challenges, and solutions regarding retrospective dosimetry in acute accidental exposures using physical methods such as electron paramagnetic resonance, thermoluminescence, and optically stimulated luminescence in biological tissues and inert materials. As research on emergency response methods faces increasing difficulties in terms of financial and human resources in many countries, it is crucial to prioritize research and focus on cost-effective paths. The paper intends to stimulate discussion in the scientific community and encourage collaboration among laboratories towards goals that address the real needs in retrospective dosimetry for acute exposures.
Article
Nuclear Science & Technology
Maha Bouhadida, Asmae Mazzi, Mariya Brovchenko, Thibaut Vinchon, Mokhtar Z. Alaya, Wilfried Monange, Francois Trompier
Summary: In this study, artificial neural networks are used to unfold neutron spectra from measured energy-integrated quantities. These spectra are important for calculating absorbed dose and kerma for radiation protection and nuclear safety. The architectures used are inspired by convolutional neural networks, with one architecture using residual transposed convolution blocks and the other being a modified version of the U-net architecture. A large and balanced simulated dataset is used to train the architectures effectively, considering realistic physical constraints. The results demonstrate high accuracy in predicting neutron spectra from thermal to fast spectrum, with dataset processing, attention to performance metrics, and hyperoptimization contributing to the robustness of the architectures.
NUCLEAR ENGINEERING AND TECHNOLOGY
(2023)
Article
Meteorology & Atmospheric Sciences
M. Pallu, S. Celestin, F. Trompier, M. Klerlein
Summary: Terrestrial gamma ray flashes (TGFs) are bursts of high-energy photons produced in thunderstorms, while electrons deliver high doses in a compact area around the TGF source. Previous studies have shown that the photon doses from TGFs are sufficiently low to be negligible for radiation exposure during flights. In this work, the upper bound probability of a commercial flight being hit by the electron beam of a TGF is estimated, and the results suggest that the probability is very low for the total air traffic.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2023)
Review
Biology
Francois Trompier, Larry A. Dewerd, Yannick Poirier, Morgane Dos Santos, Ke Sheng, Keith A. Kunugi, Thomas A. Winters, Andrea L. Dicarlo, Merriline Satyamitra
Summary: The cornerstones of science advancement are rigor, reproducibility, and unbiased reporting in scientific research. For radiation research, it is important to accurately describe experimental details and irradiation protocols for precise and reproducible dosimetry. However, many institutions conducting radiation biology research lack sufficient details in reporting their protocols, hindering balanced review and replication of experiments. To address this, experts have outlined minimum reporting standards for preclinical irradiators and dosimetry.
INTERNATIONAL JOURNAL OF RADIATION BIOLOGY
(2023)
Article
Environmental Sciences
Veronique Menard, Yoann Ristic, Francois Trompier
Summary: This study compared alanine dosimetry with ionisation chamber measurements for whole-body mouse irradiation and found reproducibility issues caused by cable twisting and irradiation of the ionisation chamber connector. Results showed a difference of up to 8.4% between alanine dosimetry and ionisation chamber measurements, and the influence of the number of animals in the sterile box on whole-body dose was found to be less than 2%.
RADIATION PROTECTION DOSIMETRY
(2023)
Editorial Material
Environmental Sciences
Shin Toyoda, Ann B. Flood, Tomisato Miura, Francois Trompier, Ruth Wilkins
RADIATION PROTECTION DOSIMETRY
(2023)
Editorial Material
Biology
Yannick Poirier, Larry A. DeWerd, Francois Trompier, Morgane Dos Santos, Ke Sheng, Keith Kunugi, Merriline M. Satyamitra, Andrea L. DiCarlo, Thomas A. Winters
RADIATION RESEARCH
(2023)
Article
Environmental Sciences
H. M. Swartz, S. G. Swarts, E. Ainsbury, R. C. Wilkins, M. Port, F. Trompier, A. B. Flood, L. Roy
Summary: There are similarities in the responses needed for managing COVID-19 and radiation injuries, as they both involve identifying and dealing with exposed individuals. Biodosimetry plays a crucial role in both situations.