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Journal of Radioanalytical and Nuclear Chemistry
Authors: Y. Keheyan, S. Khachatryan, G. Christidis, D. Moraetis, R. Gevorkyan, H. Sarkisyan, H. Yeritsyan, S. Nikoghosyan, A. Hovhannisyan, A. Sahakyan, N. Kekelidze, and L. Akhalbedashvili

Summary  

The sorptive behavior of tritiated water on natural, irradiated, chemically treated and heated at high temperatures Armenian zeolites was studied and their capacity for the separation and enrichment of tritiated water was evaluated. The distribution coefficients from the batch experiments were calculated for different zeolites and vary between 0.23 and 3.01. The influence of temperature, acidity, basicity, specific activity, electron and gamma-irradiation on sorption has been studied.

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Abstract  

Knowledge of the dynamics of HTO in leafy plant–soil system is required to verify models, such as the NORMTRI code, which predict environmental tritium following its release. Tritium concentrations in plants has been evaluated using the code NORMTRI and experimentally by collection of samples of different plants and their soils samples. In the present study, major seasonal crop plants i.e. wheat, mustard, sugar cane, coriander, spinach, potato, were collected beyond Narora Atomic Power Station site boundary and gular, arandi, neem, ashok, amaltas, csuarina leaf samples within NAPS site boundary for analysis of HTO content. Data analysis indicated that HTO in leaf is strongly influenced by atmospheric relative humidity and type of the plant.

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Abstract  

(6-3H)-Thymidine, (5-3H)-methyl-thymidine, and (5-3H)-thymidine were synthesized by the use of tritiated water. The specific activities of the products were 3.3, 3.4 and 3.0 mCi/mM, respectively. These tritiated thymidines are important tracers to study human lymphocytes and human chromosomes.

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Abstract  

The present paper reports the kinetic data on THO/H2O exchange between natural mesolite, its exchanged forms and surrounding water. The release of THO in water as a function of time, temperature and type of cationic forms was investigated. Self-diffusion coefficients and thermodynamic parameters of diffusion are evaluated. The results are compared with those of other zeolites and discussed from the point of view of using mesolite from the Tabas region, as a storage material for tritiated water.

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Abstract  

Inhibiting effect of tea catechins on the lipid peroxidation induced by tritiated water was studied. In our previous reports, it was found that the inhibiting effects of (−)-epigallocatechin gallate (EGCg) was decreased in the concentration range of above 5.0·10−5 M. In this study, the reason of decrease was revealed using fluorescence analysis and electron spin resonance, and its inhibiting mechanism of EGCg was considered. The decrease of the inhibiting effect was mainly attributed to the interaction between lipid membranes and EGCg. EGCg induced aggregation of liposomes with interacting with membranes at its concentration range of above 5.0·10−5 M. Finally, EGCg broke the membrane at its concentration range of above 1.0·10−3M. Furthermore, autoxidation of EGCg did not influence on the inhibiting effects of the lipid peroxidation under these conditions. Thus, inhibiting effect of EGCg was attributed to the amount of EGCg adsorbed on the membranes, but membrane structure was broken by adsorption of large amount of EGCg on the membranes.

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Abstract  

The recovery of humoral immune response has been comparatively studied by a radioimmunoanalysis (RIA) method and by Mancini single immunoradial diffusion method in an experiment consisting in chronic contamination with low doses of tritiated water (HTO) and oral administration of high doses of ascorbic acid on rats as radioprotector. The radioprotective effect of ascorbic acid was found to be dependent both on the radiation dose and the amount of ascorbic acid administered.

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Abstract  

The effects of incorporating tritiated water into a 14C-sampling system in sample preparation and 14C activity measurement by liquid scintillation counting were investigated. Experiments derived the limit of water content in the prepared sample, and also demonstrated that 14C activity can be determined without any interference from 3H contamination for a clear-sample solution. The results enabled us to estimate the permissible relative humidity of air required for accomplishing sample preparation and 14C activity measurement. These showed that for sampling of air with less than the permissible relative humidity, total 14C activity in airborne effluent can be evaluated accurately without dehumidification of air.

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Abstract  

The paper presents the evaluation of the humoral immune response and liver and kidney lipoperoxidation on rats acutely and chronically contaminated with low doses of tritiated water (HTO). The contamination doses for both situations were 0.5 cSv, 5 cSv and 10 cSv. By humoral immune response analysis we mean the measurement, through a radioimmunoanalysis (RIA) method, of the two intrinsic parameters of an antiserum, that is, the mean antibodies concentration and the mean antibodies affinity constant. We followed the liver and kidney lipidic peroxidation through malondialdehyde (MDA) formation assayed by the thiobarbituric acid (TBA) reaction. The humoral immune response and lipoperoxidation have been compared with the response of an uncontaminated group by the Studentt test.

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Abstract  

The aqueous solutions of 5,5-dimethyl-1-pyrroline N-oxide (DMPO) containing various amount of (-)-epigallocatechin gallate (EGCg) were mixed with tritiated water, then frozen and β-ray irradiatedin situ for 90 days at −80°C. ESR spectra were measured as a function of time after melting the sample at room temperature. The intensity of the hydroxyl (OH)_ radical adduct, DMPO-OH, was obtained by the extrapolation to zero time. The ratio of the reaction rate constants of the OH radical with EGCg and DMPO,k EGCg/k DMPO, was obtained kinetically. The result was compared with the case of DNA and EGCg in tritiated water, in order to make clear the mechanism of the protection of DNA from the radiation-induced scission with EGCg.

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Abstract  

Aqueous leaching of tritium from silica gel, loaded by absorption of water vapor, makes part of reactor de-commissioning. It is found to follow the formulation of steady-state diffusion.

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