In modern conditions, nanomaterials, especially nanoparticles of metals and nonmetals, are increasingly used in various industries. Due to their unique properties, in particular, the ability of nanoparticles to exhibit an enzyme-like effect they are widely used in biology, medicine, biotechnology, the food industry and agriculture. Important advantages of nanoparticles are their size, which enables specific properties to be present: their large surface area, the ability to transfer molecules and the ability to protect them from degradation and release over a long time, the location of action and the specificity of interaction with biological structures. Nanoparticles play a special role in the processes of neutralizing the active forms of oxygen. It has been established that a number of nanoparticles, in particular, Fe, Mn, Zn, Ce, Si and Se oxides, have an enzyme-like activity mimicking that of some enzymes. By changing the degree of oxidation, these particles can regenerate and continuously catalyze the reaction of neutralizing superoxide anion radicals, thus fulfilling the function of SOD and being the first link in protecting tissues and cells from oxidative stress in physiological and pathological conditions. It is proved that nanoparticles Mn3O4, Fe3O4, Co3O4, CeO2, LaCoO3 and other elements can effectively dispose of hydrogen peroxide and other peroxides, showing catalase-like and peroxidase-like activity. Nanozymes are characterized that exhibit the activity of oxidases, peroxidases and phosphatase. The prospect of using mimetics for complex in vitro analyzes of high-sensitivity biomarker disease detection is shown. The possibility of effective multi-use of nanoparticles as antioxidants is indicated. There are good prospects for further research on properties and the use of polyfunctional particles that are easily synthesized, reliable and inexpensive. More work is needed to determine the interaction of enzymomimetics with biological molecules such as proteins, carbohydrates and lipids, and also to take into account the peculiarities of their metabolism, clearance, degradation, biocompatibility and side effects, since individual nanoparticles have the potential to be deposited in separate organs.

Досліджено вплив термічної й термомеханічної обробки на оборотне формовідновлення при теплозмінах циліндричних пружин стискання з ефектом пам’яті форми в інтервалі температур мартенситного перетворення. Визначено залежності та встановлено режими попередньої термообробки та подальшого термосилового циклування для отримання оптимальних функціональних характеристик пружинних силових елементів.

We studied the intensity of lipid peroxidation (LPO) and the status of antioxidant system in blood of 6-60 months ostriches. We proved that specific functioning of the antioxidant system and the accumulation of lipid peroxidation intermediates characterized each period of ostrich life cycle. Thus, the period of puberty was accompanied by intensification of lipid peroxidation in ostrich blood serum and this was confirmed by a significant increase in the amount of TBA-reactive substances. This could be the consequence of the insufficient activity of enzymes of the antioxidant system (catalase, glutathione-S-transferase, glutathione reductase). The egg-laying peak was characterized by the increased body metabolism, which caused the activation of free-radical oxidation. The concentration of lipid hydroperoxides and diene conjugates increased and the TBA-reactive substances did not change significantly. Antioxidant protection of the blood during this period was mainly caused by the significant concentration of ceruloplasmin and reduced glutathione due to the increased activity of glutathione reductase. We supposed that the period of puberty and intensive period of egg laying in ostriches should be referred as the periods of stress of metabolic processes with increased intensity of lipid oxidation, associated with the certain changes in ostrich physiological and functional state.

This study presents a phenomenological model for predicting the thermomechanical behaviour of spring-type actuators made of shape memory alloys (SMAs). The model incorporates the kinetics of martensite–austenite phase transitions as a function of temperature and applied stress. The primary innovation is the inclusion of a scalar internal variable that represents the evolution of the phase transformation within a phenomenological macroscopic model. This approach enables the deformation–force–temperature behaviour of SMA-based spring elements under cyclic loading to be accurately described. A set of constitutive equations was derived to describe reversible and residual strains, along with transformation start and finish conditions. Model parameters were calibrated using experimental data from VSP-1 and TN-1K SMA springs that were subjected to thermal cycling. The validation results show a high correlation between the theoretical predictions and the experimental data, with deviation margins of less than 6.5%. The model was then applied to designing and analysing thermosensitive actuator mechanisms for temperature control systems. This yielded accurate deformation–force characteristics, demonstrating low inertia and high repeatability. This approach enables the efficient prediction and improvement of the performance of SMA-based spring elements in actuators, making it relevant for adaptive systems in marine and aerospace applications.

One of the pressing problems of modern biochemistry is the problem of adaptation of animal organism to the environment and the formation of an adaptive reaction to the negative impact of production stress factors. Among such adaptive mechanisms for rabbits in the conditions of intensive rabbit meat management is the development of oxidative stress, which causes the accumulation of reactive oxygen species in the body and the development of reactive oxygen pathology. An important role in the mechanism of adaptation of the body belongs to lipids, because they are a structural component of cell membranes and act as energy and signal systems in cells. Peroxide oxidation of lipids is a compensatory reaction that ensures the functioning of the organism for changes in the environment. The content of total lipids and peroxide oxidation products of lipids, as well as the activity of enzymes of the antioxidant defense system in rabbits from birth to 90 days of age was investigated. It has been established that the content of total lipids in brain tissues increases throughout the period of postnatal ontogenesis due to the peculiarities of the functional and metabolic activity of brain cells. The content of common lipids is closely related to the processes of lipid peroxide oxidation and the activity of enzymes of antioxidant defense. The growth in concentration of peroxide oxidation products is accompanied by a decrease in the content of total lipids in the rabbit tissues. Reduced content of TBARSproducts in rabbit brain tissue from birth to 90-day age was noted. A moderate (r = 0.66) correlation between the content of lipid conjugated dienes and lipid hydroperoxides, as well as the strong correlation (r = -0.77) between the contents of lipid conjugated dienes and TBARS-products has been established. In the heart of rabbits a reversible moderate (r = -0.62) correlation between the content of lipid conjugated dienes and lipid hydroperoxides has been revealed. Key words: rabbits, development, lipid peroxidation, brain, heart, longest muscle of the back.