Photoelectric Fields and Band Gap in Doped Lithium Niobate Crystals

Photorefractive effect was researched and band gap was determined in nominally pure congruent and stoichiometric lithium niobate crystals, and in a series of congruent LiNbO3 crystals doped by Mg, Zn, B, Gd, Y, Er cations, and LiNbO3 single crystals with double doping Mg:Gd, Mg:Fe, Mg:Y, Mg:Ta by photoinduced light scattering and optical spectroscopy methods. Keywords: lithium niobate single crystal, doping, photorefractive effect, photoinduced light scattering, optical spectroscopy, band ga

Role and Place of PET/CT in the Assessment of Skin Melanoma Prevalence

Skin melanoma is potentially the most dangerous form among all tumor skin lesions. According to statistics, melanoma accounts for about 90% of deaths. The cause of high mortality of patients is early metastasis. At the same time, melanoma metastases can be localized in almost all organs and tissues. In addition to local and regional metastasis to the skin, subcutaneous tissue and lymph nodes, metastatic melanoma of distant organs is not uncommon, and this dramatically worsens the prognosis of the disease. High-quality instrumental diagnostics at various stages of patient management (from primary diagnosis to treatment control) allow to reduce mortality and increase the overall survival of patients. Positron emission tomography in combination with computed tomography (PET/CT) has been used in the last decade as a dominant imaging method for initial staging, control of treatment and detection of progression or recurrence of various types of cancer, including melanoma. It is of great practical importance for predicting survival outcomes, assessing the risk of disease progression, as well as the effectiveness of radiation and systemic therapy. It is PET/CT that allows to simultaneously evaluate the condition of all organs and tissues with minimal radiation load being more sensitive and specific imaging method in comparison with ultrasound, CT and magnetic resonance imaging. PET/CT with <sup>18</sup>F-fluorodeoxyglucose is the most effective method for early detection of asymptomatic melanoma recurrence. In addition to accurate setting the tumor process stage, this method is crucial to ensure adequate and effective treatment, which in turn will increase the life expectancy of this category of patients in the near future

Development of beverage recipes with specified bio-corrective properties based on plant raw materials with the ultrasonic extraction method

The development of targeted beverages is a priority for healthy eating. Plant raw materials containing a wide variety of biologically active substances are used for their production. The presence of these ingredients helps to improve many physiological processes in the body, as well as to increase its immune status. The high efficiency of ultrasonic effects on various technological processes was confirmed by numerous studies. Ultrasonic extraction was carried out at t = 20 ? and an ultrasonic wave frequency of 22 kHz. As a result of the research, it was found that the equilibrium state is achieved within 15 minutes with ultrasound exposure. Natural raw materials, their chemical composition and the influence on the human body were studied in the work to develop new beverages recipes. The selected ingredients in a certain quantitative ratio made it possible to obtain beverages with improved bio-corrective properties, which allows satisfying the daily requirement of the human body for biologically active substances. Ultrasonic exposure has a positive effect on the organoleptic characteristics of the beverage and the aftertaste, as proved by the comparative organoleptic evaluation of the samples. The functional properties of the beverages developed were confirmed experimentally. The following was determined in the beverages: macronutrients content, antioxidant activity, vitamin C content, shelf life duration. The ultrasonic extraction method application in the technology of beverages manufacturing allows: to reduce the preparation time by half, to reduce the amount of raw materials by 15%, to increase the content of macronutrients by 45%, to increase the content of vitamin C by 35%, to increase the antioxidant activity by 45-50%, to increase storage stability by 50-60%, to improve organoleptic characteristics. The results obtained prove the intensifying effect of ultrasonic exposure in the production of functional beverages