Experimental studies of the thermal regime of the room when using heating ceramic panels

The article presents the results of experimental studies of the parameters of ceramic panels. Experimental measurements of air temperature in a room for which an electric ceramic panel is used as heating devices are given. The automatic system of monitoring of temperature in the room is described. During the experiments it was determined that the surface temperature of the ceramic plate of the heater is higher in the center and decreases when approaching the edges. It is proved that the use of constant surface temperature is acceptable in CFD modeling of a room with ceramic electric heaters. The profile of temperature distribution on height of the room at its heating by means of an electric ceramic heater is resulted in work. The air temperature is relatively evenly distributed over the height of the room. In this study, when entering the quasi-stationary mode, the air temperature in the height of the room varied in the range from 24 to 27˚C, which is slightly higher than the norm for the temperature in domestic premises. In order to save energy in this case it is necessary to reduce the service life of ceramic electric heaters. In the future it is necessary to develop a thermophysical numerical model and verify it with the help of the obtained experimental data. In addition, with the help of the model you can conduct research and determine the optimal location of ceramic electric heaters in the space of the room. Key words: radiation ceramic heater, experimental research, temperature monitoring.

Radioprotective effect of a combination of melatonin and metformin on mice spermatogenesis: A histological study

Background: The spermatogenesis system includes highly radiosensitive cells. Hence, this system is a potential target for toxic effects of ionizing radiation during radiotherapy of abdomen and pelvis cancers, as well as after accidental radiation events. Accordingly, metformin and melatonin are two important radioprotectors that have shown an ability to prevent cell death through neutralization of free radicals and stimulating DNA damage responses. Objective: To evaluate the radioprotective effects of melatonin and metformin on mice spermatogenesis when administered alone or as a combination. Materials and Methods: In this histological Study, 40 (6-8 wk, 30 gr) NMRI mice were divided into 8 groups (n = 5/each) as control, metformin, melatonin, melatonin + metformin, radiation, radiation + melatonin, radiation + metformin, and radiation + melatonin + metformin. 37 days after the irradiation, the testicular tissues were collected for histological evaluation. Results: Single administration of melatonin could ameliorate effectively radiation toxicity in mice testis. Metformin showed radioprotective effects on some parameters such as the numbers of spermatogonia and mature sperms. Interestingly, the melatonin and metformin combination reversed the reduced number of sperms rather than single drug administration. Conclusion: The combination of melatonin with metformin can protect mice spermatogenesis against ionizing radiation more effectively compared to the single forms of these drugs. Key words: Radiation, Testis, Leydig cells, Melatonin, Metformin, Spermatogenesis.

Radiation visualization in radiation oncology

According an implementation in clinic practice new stereotactic and modulated methods, hadrontherapy, which significantly upgrade the precise of dose delivery, the optimization of radiotherapy planning is especially important. In review the role of modern methods of visualization in all stages of radiation therapy – simulation, planning, dose delivery monitoring and assessment therapeutic effect was revealed. The usefulness of wide using of the morphological and functional methods of MRI, PET/CT with metabolic and receptor markers, ultrasonography, which can upgrade precision of a radiation therapy planning and improve a monitoring of therapeutic processes, was showed. Key words: radiation therapy planning, magnetic resonance imaging, positron emission tomography, computed tomography.