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Radiotherapy affects not only malignant, but also a healthy tissue adjacent to tumor by increasing reactive oxygen species generation, with consequent damage to biomolecules, such as the oxidation of membrane lipids, known as lipid peroxidation. The end product of lipid peroxidation is malondialdehyde. Radioprotectors are compounds that could significantly protect normal cells from radiation, without changing the tumor cell radiosensitivity. Synthetic radioprotectors usually have side effects and are toxic. Natural radioprotectors exert protection without adverse effects. In this study, we examined the radioprotective ability of linden honey in rat blood, by detecting alterations in the activities of antioxidant enzymes catalase and glutathione peroxidase and malondialdehyde concentration after the exposure to a therapeutic dose of gamma rays. Sixteen rats were randomly divided into Control and Honey groups. Honey group received honey (1.5 mL(kgd-1)) orally for four weeks, while at the same time Control group were given distilled water. After four weeks, blood was sampled from all animals. Samples were halved, and one series of samples were gamma irradiated (2 Gy). Radiation induced decreased glutathione peroxidase activity and increased malondialdehyde level, while honey treatment attenuated those alterations, keeping glutathione peroxidase and malondialdehyde at physiological levels. These findings confirm radioprotective properties of linden honey.

The aim of the study was to assess Cs+ ions transport phenomena from solidified spent ion exchange resin by mathematical modeling. The experimental results comparison was obtained by Hespe's Standard Leaching Method. For the leaching prediction rate as a function of time, diffusion and semi-empirical models were used. Due to the presence of spent ion exchange resin, the cement matrix absorbed a larger amount of water, swelled, and degraded. This phenomenon caused a significantly lower value of mechanical resistance to pressure. Also, through the increase of bentonite and zeolite content, the cement matrix decreased its mechanical resistance. The retention of cesium ions in the cement matrix was low and they were leached during the early phase of the investigation. The diffusion coefficient, De, decreased by three orders of magnitude with the addition of zeolite and bentonite in the cement matrix. Linear regression of experimental Cs+ leaching results, under static conditions, displayed that the semi-empirical parameter K3 than the absolute values of the parameters K2 and K1. Therefore, the contribution of matrix dissolution to the total radionuclides transport was irrelevant to the prevailing share of diffusion and surface washing processes.

The possibility of retaining Cs+ and Co2+ bound by immobilization processes in the cement matrix is defined as the subject of its investigation: the cement matrix formulation, the water/cement ratio, the amount of waste, and the porosity of such a structure. Implementing the standard leaching method by Hespe the possibility of comparing different authors' results was achieved. Diffusion and semi-empirical model were used to investigate the transport phenomenon in order to predict the leaching level for a long period of time. Leaching of Co2+ and Cs+ ions under dynamic conditions immobilized in the cement matrix dynamic conditions decreases with the increase of the sludge content, regarding porosity increase. The effects of the diffusion and surface washing are equalized, and the contribution of the matrix dissolution to the Cs+ and Co2+ transport in the cement porous media increases, on average, for one order of magnitude. The semi-empirical model gives a better approximation for Co2+ and Cs+ leaching process for the duration of the experiment while both models significantly approximate leaching results in dynamic conditions. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III 43009]

Fluorapatite nanopowders with different amounts of fluoride ions were prepared using the surfactant-assisted microwave method under isothermal conditions. Microwave irradiation was applied for the rapid formation of crystals. A micellar solution of polyoxyethylene (23) lauryl ether was used as a regulator of nucleation and crystal growth. Characterization studies from X-ray diffraction, field-emission scaning electron microscopy and Fourier-transform infrared spectra showed that crystals have an apatite structure and particles of all samples are nano size, with an average length of 50 nm and about 15-25 nm in diameter. Antimicrobial studies have demonstrated that synthesized fluorapatite nanopowders exhibit activity against tested pathogens: Escherichia coli, Staphylococcus aureus and Candida albicans. Activity increased with the amount of fluoride ions. The synthesized fluorapatite nanomaterials are promising as materials in environmental protection and medicine for orthopedics and dental restorations. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III 43009]

Artificially contaminated soil, with mixture of Co(II) and Sr(II) ions in different proportions, was tested. The main aim was to investigate the possibility of ethylenediaminetetraacetic acid (EDTA) utilization in the chemical extraction process as a method for soil remediation in the case of mixed contamination. The efficiency of this process when EDTA of 5×10-4 molL-1 was used was low, while the application of the EDTA solution of the initial concentration 5×10-3 molL-1 or higher showed almost the same efficiency. This suggested that the application of the solution EDTA (5×10-3 molL-1) is optimal from the aspect of cost and degradation of soil properties. Furthermore, process kinetic was fitted using one parameter shrinking core models. Kinetic data modeling showed that the process is complex, demanding multi resistance kinetic model. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III 43009]