scholarly journals Advances in EPR Dosimetry in Terms of Retrospective Determination of Absorbed Dose in Radiation Accidents

2018 ◽  
Vol 41 (1) ◽  
pp. 11-21 ◽  
Author(s):  
Tomasz Kubiak
Keyword(s):  
Tooth Enamel ◽  
Absorbed Dose ◽  
In Vivo Dosimetry ◽  
Paramagnetic Resonance ◽  
Radiation Accidents ◽  
X Band ◽  
Cumulative Radiation Dose ◽  
The Moment

AbstractThe electron paramagnetic resonance measurements of dosimetric signals originating from radicals generated under the influence of ionizing radiation allow to determine the dose absorbed by the casualties of radiation accidents. The study material can consist of victim’s teeth, bones or nails. Also human hair and mineral glass from personal electronic devices, that people had in the moment of accident, are considered to be useful in dosimetry. Although X-band (9.4 GHz) spectrometers predominate, Q-band devices (34 GHz) enable to increase the sensitivity of measurements and reduce the size of specimens, whereas L-band machines (1.1 GHz) are suitable for in vivo dosimetry. The EPR tooth enamel dosimetry has been used many times to assess the cumulative radiation dose and health risk in people living in areas contaminated due to the radiation accidents and to determine the unknown absorbed doses in patients after the overexposures during radiotherapy treatment.

Quality assurance in radiotherapy by in vivo dosimetry. 2. Determination of the target absorbed dose

1990 ◽  
Vol 19 (1) ◽  
pp. 73-87 ◽  
Author(s):  
G. Leunens ◽  
J. Van Dam ◽  
A. Dutreix ◽  
E. van der Schueren
Keyword(s):  
Quality Assurance ◽  
Absorbed Dose ◽  
In Vivo Dosimetry

Systematic in vivo dosimetry for quality assurance using diodes 2: Assessing radiotherapy techniques and developing an appropriate action protocol

2004 ◽  
Vol 4 (4) ◽  
pp. 143-154 ◽  
Author(s):  
R. Appleyard ◽  
K. Ball ◽  
F. E. Hughes ◽  
W. Kilby ◽  
R. Nicholls ◽  
...  
Keyword(s):  
Head And Neck ◽  
In Vivo Dosimetry ◽  
Entrance Dose ◽  
Treatment Category ◽  
P Type ◽  
Dose Measurements ◽  
Action Levels

Purpose: Having previously reviewed the implementation of systematic in vivo dosimetry at the Norfolk and Norwich Hospital this paper examines the results of entrance dose measurements for specific sites/techniques and determines whether different action/alert protocols are required for these different categories.Methods and materials: Entrance dose measurements using p-type diodes were analysed for the following treatment categories: Breast, head and neck in beam direction shell, abdomino-pelvic and intrathoracic. A 4% tolerance was applied.Results: Mean deviations from expected dose and proportion of measurements exceeding tolerance were: Breast: +1.15%±3.04% (1SD), 238/1073≥4%; Head and neck: +0.35%±2.20% (1SD), 21/326≥4%; Abdomino-pelvic: +0.52%±2.75% (1SD), 93/712≥4%; Intrathoracic: −0.01%±2.75% (1SD), 22/119≥4%. Significant improvements in results for breast patients were noted following the introduction of a commercial breast board. The results for abdomino-pelvic patients confirmed a substantial variation in diode response under short FSD, wedged fields at 16MV (that had not been corrected for). The statistical uncertainty in dose measurement for each treatment category was calculated in order to assist determination of appropriate tolerance levels.Conclusions: A blanket tolerance of 4% was generally too low given the extent of measurement uncertainty. The relatively high number of readings outside tolerance where identification of errors was difficult/impossible resulted in inconsistent application of the action protocol. Some widening of tolerances is likely to improve quality of procedure and treatment. Appropriate action levels are recommended for each treatment category.

scholarly journals Resolved Hyperfine at L-band for High-Spin CoEDTA, A Model for Co Sites in Proteins

2019 ◽  
Vol 20 (10) ◽  
pp. 2385
Author(s):  
William E. Antholine
Keyword(s):  
Accurate Determination ◽  
Cobalt Complex ◽  
Low Frequency ◽  
Paramagnetic Resonance ◽  
X Band ◽  
Epr Parameters ◽  
L Band ◽  
Band Spectra

Low-frequency electron paramagnetic resonance (EPR) spectra were obtained for the Co complex of ethylene diamine tetraacetic acid (CoEDTA). It was found that the cobalt hyperfine at geff-mid is better resolved at a low frequency, L-band (1.37 GHz), and not resolved at X-band (9.631 GHz), which is the conventional frequency used for most spectra for metal complexes. Resolved cobalt hyperfine lines lead to additional EPR parameters like A-mid for cobalt and a more-accurate determination of g-mid. Resolved hyperfine lines in the L-band, but not the S-band, spectra were obtained at a concentration of 1 mM. Knowing these additional EPR parameters provides a means to better determine the electron density in the ground state orbital for each cobalt complex, as well as to determine differences upon a change of ligation. If zinc sites can be replaced by cobalt, the cobalt spectra for these sites will enhance the characterization of the zinc sites.

scholarly journals Determination of the Antioxidant Status of the Skin by In Vivo-Electron Paramagnetic Resonance (EPR) Spectroscopy

Cosmetics ◽  
2015 ◽  
Vol 2 (3) ◽  
pp. 286-301 ◽  
Author(s):  
Silke Lohan ◽  
Anna-Christina Lauer ◽  
Sophia Arndt ◽  
Annette Friedrich ◽  
Kathrin Tscherch ◽  
...  
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Epr Spectroscopy ◽  
Antioxidant Status ◽  
Paramagnetic Resonance ◽  
Electron Paramagnetic

scholarly journals STUDY OF REMINERALIZING ACTIVITY OF DOSAGE FORMS FOR TREATMENT OF INITIAL ENAMEL CARIES

2018 ◽  
Vol 6 (4) ◽  
pp. 380-388
Author(s):  
A. L. Golovanenko ◽  
E. V. Tretyakova ◽  
E. S. Patlusova ◽  
I. V. Alekseeva ◽  
E. S. Berezina ◽  
...  
Keyword(s):  
Tooth Enamel ◽  
Dosage Forms ◽  
Gelling Agent ◽  
Enamel Caries ◽  
Method Of Determination ◽  
Enamel Structure ◽  
Calcium And Phosphorus

One of the most promising areas of dental caries prophylaxis is remineralizing therapy aimed at normalizing the mineral composition of tooth enamel. As a result of a set of scientific, experimental and clinical studies, gels and drug films for the treatment of enamel caries have been developed.The aimof this work is to study remineralizing activity of dosage forms for the treatment of initial enamel caries.Materials and methods.As active pharmaceutical substances in dosage forms, calcium chloride (FS 42-0006-5675-04 P.003964.01), potassium phosphate disubstituted (FS 42-1297-79), sodium fluoride (PS.2.2.0013.15), auxiliary substances – gelling agent sodium-carboxymethylcellulose (sodium-CMC) C75 (TU 6-55-39-90), plasticizer glycerin (PS.2.2.0006.15), purified water (PS.2.2.0020.15) – have been used. Remineralizing activity was studied by the method of determination of calcium and phosphorus in the enamel ash in vitro. The study of remineralizing activity was carried out by the method of determination of calcium and phosphorus in the enamel ash in vitro. Quantitative determination of calcium was carried out by reverse complexometric titration, and the one of phosphorus was carried out by photoelectrocolorimetry. The electro-metric study of the enamel electrical conductivity was also carried out in vivo with the help of the Dentest device (Geosoft).Results and discussion. The method of determination of calcium and phosphorus in the enamel ash in vitro is based on tooth ashing and the subsequent determination of calcium and phosphorus in it by chemical and instrumental methods. Basing on the results obtained, it has been established that gel and drug films used for enamel caries treatment significantly increase the content of calcium and phosphorus in tooth enamel. The conducted electrometric study confirmed the increase in the hardness of the enamel structure due to its remineralization after the use of drug films.Conclusion. As a result of the studies conducted in vivo and in vitro, it has been established that the developed dosage forms have a remineralizing effect and can be recommended for increasing the effectiveness of prevention and treatment of the initial enamel caries.

scholarly journals Developments in Biodosimetry Methods for Triage With a Focus on X-band Electron Paramagnetic Resonance In Vivo Fingernail Dosimetry

2018 ◽  
Vol 115 (1) ◽  
pp. 140-150 ◽  
Author(s):  
Steven G. Swarts ◽  
Jason W. Sidabras ◽  
Oleg Grinberg ◽  
Dmitriy S. Tipikin ◽  
Maciej M. Kmiec ◽  
...  
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Paramagnetic Resonance ◽  
Band Electron ◽  
X Band ◽  
Electron Paramagnetic ◽  
Fingernail Dosimetry

scholarly journals X-Band Rapid-Scan Electron Paramagnetic Resonance of Radiation-Induced Defects in Tooth Enamel

2015 ◽  
Vol 184 (2) ◽  
pp. 175 ◽  
Author(s):  
Zhelin Yu ◽  
Alexander Romanyukha ◽  
Sandra S. Eaton ◽  
Gareth R. Eaton
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Tooth Enamel ◽  
Paramagnetic Resonance ◽  
Rapid Scan ◽  
X Band ◽  
Radiation Induced ◽  
Induced Defects ◽  
Electron Paramagnetic
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