Investigation of the Radiation-Induced Signal of Electron Paramagnetic Resonance of Eggshell after Irradiation with Electron Beams

ANRI ◽  
2021 ◽  
Vol 0 (2) ◽  
pp. 75-84
Author(s):  
Anastasia Chumanova ◽  
Ruslan Vazirov ◽  
Sergey Sokovnin ◽  
Ekaterina Agdantseva ◽  
Anton Tsmokalyuk
Keyword(s):  
Comparative Analysis ◽  
Absorbed Dose ◽  
Radiation Processing ◽  
Paramagnetic Resonance ◽  
Radiation Induced ◽  
Epr Signal ◽  
Induced Signal ◽  
Chicken Eggs ◽  
Kinetics Of ◽  
Over Time

Because of the development of radiation processing of food and agricultural products it requires new methods of control over the processing and turnover of products. A promising method for monitoring is EPR spectrometry. This research presents the results of a study of the radiation induced EPR signal in eggshells. The URT-0.5 (0.5 MeV) and UALR-10-10 S2 (10 MeV) accelerators were used for irradiation. It shows the kinetics of radicals over time. The dependences of the EPR signal intensity on the absorbed dose were obtained, and a comparative analysis of the irradiation of chicken eggs with different energies was performed. The kinetics of radicals over time and the dependence of the intensity of the EPR signal on the absorbed dose are shown. A comparative analysis of the irradiation of chicken eggs with different energies is carried out.

scholarly journals Kinetics of increased generation of (.)NO in endotoxaemic rats as measured by EPR.

2003 ◽  
Vol 50 (3) ◽  
pp. 807-813 ◽  
Author(s):  
Przemyslaw M Plonka ◽  
Stefan Chlopicki ◽  
Magdalena Wisniewska ◽  
Beata K Plonka
Keyword(s):  
Hyperfine Splitting ◽  
Spin Trap ◽  
Oxidant Stress ◽  
No Production ◽  
Paramagnetic Resonance ◽  
Epr Signal ◽  
High Level ◽  
Kidney Liver ◽  
Electron Paramagnetic ◽  
Kinetics Of

Ferrous-diethyldithiocarbamate (Fe(DETC)(2)) chelate is a lipophilic spin trap developed for (.)NO detection by electron paramagnetic resonance (EPR) spectroscopy. Using this spin trap we investigated the kinetics of (.)NO production in endotoxaemia in rats induced by lipopolysaccharide (Escherichia coli, 10 mg/kg). The NO-Fe(DETC)(2) complex was found to give a characteristic EPR signal, and the amplitude of the 3rd (high-field) component of its hyperfine splitting was used to monitor the level of (.)NO. We found that in blood, kidney, liver, heart and lung (.)NO production starts to increase as early as 2 h after LPS injection, reaches the maximum 6 h after LPS injection and then returns to basal level within further 12-18 h. Interestingly, in the eye bulb the maximum of (.)NO production was detected 12 h after LPS, and the signal was still pronounced 24 h after LPS. In brief, the highly lipophilic exogenous spin trap, Fe(DETC)(2) is well suited for assessment of (.)NO production in endotoxaemia. We demonstrated that the kinetics of increased production of (.)NO in endotoxaemic organs, with the notable exception of the eye, do not follow the known pattern of NOS-2 induction under those conditions. Accordingly, only in early endotoxaemia a high level of (.)NO is detected, while in late endotoxaemia (.)NO detectability is diminished most probably due to concomitant oxidant stress.

scholarly journals On the Mechanism and Kinetics of Synthesizing Polymer Nanogels by Ionizing Radiation-Induced Intramolecular Crosslinking of Macromolecules

Pharmaceutics ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1765
Author(s):  
Aiysha Ashfaq ◽  
Jung-Chul An ◽  
Piotr Ulański ◽  
Mohamad Al-Sheikhly
Keyword(s):  
Ionizing Radiation ◽  
Absorbed Dose ◽  
Kinetics And Mechanism ◽  
Background Information ◽  
Potential Applications ◽  
Radiation Induced ◽  
Mechanism And Kinetics ◽  
Kinetics Of ◽  
Crosslinking Agents

Nanogels—internally crosslinked macromolecules—have a growing palette of potential applications, including as drug, gene or radioisotope nanocarriers and as in vivo signaling molecules in modern diagnostics and therapy. This has triggered considerable interest in developing new methods for their synthesis. The procedure based on intramolecular crosslinking of polymer radicals generated by pulses of ionizing radiation has many advantages. The substrates needed are usually simple biocompatible polymers and water. This eliminates the use of monomers, chemical crosslinking agents, initiators, surfactants, etc., thus limiting potential problems with the biocompatibility of products. This review summarizes the basics of this method, providing background information on relevant aspects of polymer solution thermodynamics, radiolysis of aqueous solutions, generation and reactions of polymer radicals, and the non-trivial kinetics and mechanism of crosslinking, focusing on the main factors influencing the outcomes of the radiation synthesis of nanogels: molecular weight of the starting polymer, its concentration, irradiation mode, absorbed dose of ionizing radiation and temperature. The most important techniques used to perform the synthesis, to study the kinetics and mechanism of the involved reactions, and to assess the physicochemical properties of the formed nanogels are presented. Two select important cases, the synthesis of nanogels based on polyvinylpyrrolidone (PVP) and/or poly(acrylic acid) (PAA), are discussed in more detail. Examples of recent application studies on radiation-synthesized PVP and PAA nanogels in transporting drugs across the blood–brain barrier and as targeted radioisotope carriers in nanoradiotherapy are briefly described.

Kinetics of Radiation-Induced Graft Copolymerization of Vinylbenzyl Chloride onto Nylon Fibers

2015 ◽  
Vol 719-720 ◽  
pp. 63-66 ◽  
Author(s):  
T.M. Ting ◽  
Mohamed Mahmoud Nasef ◽  
Kamaruddin Hashim
Keyword(s):  
Activation Energy ◽  
Fourier Transform ◽  
Graft Copolymerization ◽  
Monomer Concentration ◽  
Absorbed Dose ◽  
Nylon 6 ◽  
Kinetic Rate ◽  
Radiation Induced ◽  
Ft Ir ◽  
Kinetics Of

The graft copolymerization of vinylbenzyl chloride (VBC) onto nylon-6 fiber was investigated by the pre-irradiation method using electron beam. The effects of grafting parameters, monomer concentration, absorbed dose and reaction temperature were investigated. The empirical kinetic rate equation dGo/dt=k[M]^0.86*[D]^1.06 was used to describe grafting of VBC onto nylon-6. The overall activation energy for graft copolymerization of VBC was found to be 22.6 kJ/mol. The results revealed that the grafting kinetic was controlled by the amounts of trapped radicals and monomer molecules. Fourier transform infrared (FT-IR) was used to provide evidence for the formation of grafted copolymers.

scholarly journals The influence of iron on selected properties of synthetic pheomelanin

2020 ◽  
Vol 78 (2) ◽  
pp. 181-189
Author(s):  
Andrzej Zadlo ◽  
Krystian Mokrzyński ◽  
Shosuke Ito ◽  
Kazumasa Wakamatsu ◽  
Tadeusz Sarna
Keyword(s):  
Metal Ion ◽  
Transition Metal Ions ◽  
Enzymatic Oxidation ◽  
Diethylenetriaminepentaacetic Acid ◽  
Paramagnetic Resonance ◽  
Time Resolved ◽  
Epr Signal ◽  
Electron Paramagnetic ◽  
Kinetics Of ◽  
High Spin Iron

Abstract It is believed that while eumelanin plays photoprotective and antioxidant role in pigmented tissues, pheomelanin being more photoreactive could behave as a phototoxic agent. Although the metal ion-sequestering ability of melanin might be protective, transition metal ions present in natural melanins could affect their physicochemical properties. The aim of this research was to study iron binding by pheomelanin and analyze how such a binding affects selected properties of the melanin. Synthetic pheomelanin (CDM), prepared by enzymatic oxidation of DOPA in the presence of cysteine was analyzed by electron paramagnetic resonance (EPR) spectroscopy, spectrophotometry, chemical analysis, and time-resolved measurements of singlet oxygen phosphorescence. Iron broadened EPR signal of melanin and increased its optical absorption. Iron bound to melanin exhibited EPR signal at g = 4.3, typical for high-spin iron (III). Iron bound to melanin significantly altered the kinetics of melanin photodegradation, which in turn modified the accessibility and stability of the melanin–iron complexes as indicated by the release of iron from melanin induced by diethylenetriaminepentaacetic acid and KCN. Although bound to melanin iron little affects initial stages of photodegradation of CDM, the effect of iron becomes more pronounced at later stages of melanin photolysis.

Changes of Free Radical Content in Exposed to Electrons GUR1020 and GUR1050 Polyethylene Types Intended for Endoprosthesis Acetabular Cups

2013 ◽  
Vol 199 ◽  
pp. 544-549 ◽  
Author(s):  
Piotr Czaja ◽  
Joanna Maszybrocka ◽  
Jacek Michniowski ◽  
Jerzy Cybo ◽  
Adrian Barylski
Keyword(s):  
Free Radical ◽  
Thermal Processing ◽  
Atmospheric Oxygen ◽  
Absorbed Dose ◽  
Peroxyl Radicals ◽  
Characteristic Lines ◽  
Epr Signal ◽  
Radical Content ◽  
Changes Over Time ◽  
Over Time

The paper presents the results of the EPR examination of free radical content in GUR1020 and GUR1050 polyethylenes which were irradiated with an electron beam. Changes in the amount of radicals in the period of 12 months in the UHMWPE cross-linked with a dose of 26-156 kGy were analysed. Spectra registered 90 days after irradiation show a hyperfine structure. An image consisting of 7 characteristic lines is the most similar pattern that can be used to analyse this spectrum. Subsequent measurements (255 and 372 days after irradiation) produce images consisting of one resonance line. Alkyl and allyl radicals generated during the irradiation are the source of the EPR signal. The influence of atmospheric oxygen causes further changes of the radicals mentioned above, which leads to the formation of peroxyl radicals. The content of radicals in the polymer and its changes over time were calculated. The amount of radicals increases as the absorbed dose grows, but decreases over time. Comparative measurements of the material subjected to thermal processing at the temperature of 423 K have shown that in this case, no resonance lines are present, which testifies to the effective elimination of free radicals by means of UHMWPE recrystallisation.

EPR measurement of environmental radiation using human fingernails

2018 ◽  
Vol 106 (8) ◽  
pp. 703-707
Author(s):  
Abbas Noori ◽  
Farhood Ziaie ◽  
M. Mostajab
Keyword(s):  
Radiation Dose ◽  
Chemical Treatment ◽  
Research Work ◽  
Absorbed Dose ◽  
Limiting Factors ◽  
Treatment Procedure ◽  
Response Curves ◽  
Environmental Radiation ◽  
Radiation Induced ◽  
Induced Signal

Abstract In this research work, human fingernails were utilized to estimate the radiation dose using EPR measurements of radiation-induced radicals. The limiting factors in this research were the presence of mechanical induced EPR signals due to the mechanical stress during the preparation of the samples. The mechanically induced signals overlap with the radiation-induced signal, which considerably can overestimate the dose. Thus, different treatment methods of fingernails were used to reduce the mechanical induced signals. The results demonstrate that the mechanical and radiation induced signals have apparently different microwave power saturation behavior. Also, mechanical induced signal shows a fading evolution vs. time and reaches to a constant value. Chemical treatment using the different reagents showed that the minimum mechanical induced signal was obtained using the dithiothreitol reagent. The dose response curves of the treated samples with dithiothreitol for 30 min demonstrated a more linearity, and closer curves in comparison to those treated in 5 min. Therefore, to find out an unknown absorbed dose in a fingernail sample using a calibration curve, it could be recommended to use the mentioned chemical treatment procedure to reduce the uncertainty.

Radiation-induced reactions with cellulose. IV. Electron paramagnetic resonance studies of radical formation

1967 ◽  
Vol 20 (5) ◽  
pp. 911 ◽  
Author(s):  
S Dilli ◽  
IT Ernst ◽  
JL Garnett
Keyword(s):  
Paramagnetic Resonance ◽  
Copper Sulphate Solution ◽  
Factors Affecting ◽  
Radical Decay ◽  
Radical Concentration ◽  
Radiation Induced ◽  
Cellulose Iv ◽  
Electron Paramagnetic ◽  
Kinetics Of ◽  
Significant Concentration

The radiation-induced formation of trapped radicals in cellulose, both in vacuum and air, has been studied by e.p.r, spectroscopy. Factors affecting radical concentration have been examined, including total dose, dose rate, heat, cellulose pretreatment, and kinetics of radical decay. All spectra were asymmetric in shape. Variables affecting line shape have been studied, including oxygen, irradiation conditions such as the presence of water, acetic acid, copper sulphate solution, methanol, ethanol, potassium iodide, and liquid ammonia. The data indicate that the observed cellulose e.p.r, spectrum is composed of an overlapping singlet with a triplet. Studies of radical decay show that a significant concentration of e.p.r. species still remains in irradiated cellulose after 4 years at ambient temperature.

scholarly journals EPR Study of Paramagnetic Defects in Clay Minerals

Mineralogia ◽  
2007 ◽  
Vol 38 (2) ◽  
pp. 125-138
Author(s):  
Joanna Babińska ◽  
Krystyna Dyrek ◽  
Piotr Wyszomirski
Keyword(s):  
Clay Minerals ◽  
Metal Ion ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Resonance Spectroscopy ◽  
Radioactive Elements ◽  
Paramagnetic Resonance ◽  
Radiation Induced ◽  
Epr Signal ◽  
Induced Defects ◽  
Electron Paramagnetic

EPR Study of Paramagnetic Defects in Clay MineralsRadiation induced defects (RID-s) and transition metal ion impurities were revealed by EPR (Electron Paramagnetic Resonance) spectroscopy in kaolinites from a number of Polish deposits. Arelationship between the intensity of the EPR signals of the RID-s and quantity of radioactive elements was defined in these minerals. In one of the deposits of kaolinites (Wyszonowice) the EPR signal intensity depends on grain size. Other clay minerals studied (illites, montmorillonites) only show weak signals of the RID type.

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