Estimated Inpatient Hospital Stay in Individual Wards: Guidelines on Radiation Safety after Radioiodine Therapy

Radionuclide therapy safety requirements are regulated by the Russian Radiation Safety Standards (RRSS), which state the maximum allowed radionuclide activity in the body and the equivalent dose rate (EDR) of gamma radiation. Therefore, it is necessary to estimate the time of an inpatient hospital stay in specially designed radionuclide therapy wards. The article presents the findings of individual 131I biokinetics studies in 64 patients admitted to radioiodine therapy of thyrotoxicosis and differentiated thyroid cancer. We developed a method to calculate the time interval to reach the EDR of 20μSv/h and the recommended EDR of 3 and 0.3μSv/h for adults and children, respectively. It is based on the measurement of the 131I excretion constant. Keywords: Radioiodine therapy, Radiation safety, Guidelin

EQCM study of redox properties of PEDOT/MnO2 composite films in aqueous electrolytes

Electrochemical behavior of poly-3,4-ethylenedioxythiophene composites with manganese dioxide (PEDOT/MnO2) has been investigated by cyclic voltammetry and electrochemical quartz crystal microbalance at various component ratios and in different electrolyte solutions. The electrochemical formation of PEDOT film on the electrode surface and PEDOT/MnO2 composite film during the electrochemical deposition of manganese dioxide into the polymer matrix was gravimetrically monitored. The mass of manganese dioxide deposited into PEDOT at different time of electrodeposition and apparent molar mass values of species involved into mass transfer during redox cycling of PEDOT/MnO2 composites were evaluated. It was found that during the redox cycling of PEDOT/MnO2 composite films with various MnO2 content, the oppositely directed fluxes of counterions (anions and cations) occur, resulting in a change of the slope of linear parts of the Delta f-E plots with changing the mass fraction of MnO2 in the composite film. Rectangular shape of cyclic voltammograms of PEDOT/MnO2 composites with different loadings of manganese dioxide was observed, which is characteristic of the pseudocapacitive behavior of the composite material. Specific capacity values of PEDOT/MnO2 composites obtained from cyclic voltammograms were about 169 F g(-1). The specific capacity, related to the contribution of manganese dioxide component, was about 240 F g(-1)