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Significant evidence suggests that misfolded alpha‐synuclein (aSyn), a major component of Lewy bodies, propagates in a prion‐like manner contributing to disease progression in Parkinson's disease (PD) and other synucleinopathies. In fact, timed inoculation of M83 hemizygous mice with recombinant human aSyn preformed fibrils (PFF) has shown symptomatic deficits after substantial spreading of pathogenic alpha‐synuclein, as detected by markers for the phosphorylation of S129 of aSyn. However, whether accumulated toxicity impact human‐relevant cognitive and structural neuroanatomical measures is not fully understood. Here we performed a single unilateral striatal PFF injection in M83 hemizygous mice, and using two assays with translational potential, ex vivo magnetic resonance imaging (MRI) and touchscreen testing, we examined the combined neuroanatomical and behavioral impact of aSyn propagation. In PFF‐injected mice, we observed widespread atrophy in bilateral regions that project to or receive input from the injection site using MRI. We also identified early deficits in reversal learning prior to the emergence of motor symptoms. Our findings highlight a network of regions with related cellular correlates of pathology that follow the progression of aSyn spreading, and that affect brain areas relevant for reversal learning. Our experiments suggest that M83 hemizygous mice injected with human PFF provides a model to understand how misfolded aSyn affects human‐relevant pre‐clinical measures and suggest that these pre‐clinical biomarkers could be used to detect early toxicity of aSyn and provide better translational measures between mice and human disease. [ABSTRACT FROM AUTHOR]

Due to their unique physical properties, magnetic fluids are promising for use in bearings, seals, sliding guides, and other devices of modern technology. Some restrictions on their use are imposed by the tendency of magnetic fluids to lose colloidal stability and structure formation in strong magnetic fields. Increasing the stability of a colloid by reducing the size of the dispersed particles of the magnetic fluid is limited by the Heisenberg uncertainty relation, on the condition of maintaining their ferromagnetic state. The search for ways to reduce internal friction in technical devices with magnetic fluids having a highly developed thixotropic nanostructure is important from a practical point of view. Using a device, simulating the operation of a magnetohydrostatic bearing, the rheological characteristics of a fluid nanostructured by a magnetic field, which is a colloidal system with a dispersed phase of magnetite particles (10 vol.%) and a dispersion medium of silicon organic fluid PESV-2, were studied. The dynamic viscosity of the magnetic fluid was about 0.05 Pa.s at 20°C. It has been established that the process of structuring a magnetic fluid in an external field can last hundreds of hours and depends mainly on the viscosity of the dispersion medium and the concentration of magnetite. It has been revealed that the motion of a cylinder with a terminal velocity begins only at shear stresses exceeding the limiting static stress and proceeds at a constant velocity. The breakdown of the structure begins after the shear stress exceeds the critical value. The critical stress is introduced to compare the strength of the structure of different fluids. The value of the critical stress was determined with an accuracy of up to 50 Pa by analyzing the curves of the change in the sliding speed with time. It has been established that the temperature dependence of the critical shear stress is very sharp and close to exponential.

The technology of microarc oxidation of valve metals is one of the promising methods for engineering the working surface of friction units of modern technology. As a result of the versatility of the technology, it is possible to obtain composite ceramic coatings and materials of various types. Their properties are set by the electrical modes of material formation, the chemical composition of the electrolyte, and the possible further modification of the ceramic matrix with micro- and nanosized tribofillers. Based on the practical results of their research in the field of creating coatings of various types by microarc oxidation, an analysis is given of the main areas of application of microplasma electrolytic oxidation technology, their advantages over other methods of surface modification, structure and properties of the materials obtained. It is possible to distinguish the modification of the friction surface of a part by the method of microplasma electrolytic oxidation in order to increase its hardness and wear resistance. Good results were obtained in increasing the wear resistance of the hardened working surface of the spinning machine parts, the number of equipment repairs was reduced by more than 20 times. The use of microarc oxidation is promising for the preparation of composite coatings, which are a ceramic matrix in which solid lubricating dispersed particles are embedded. The technology of forming a matrix on aluminum, modified with dispersed magnetite, graphite and molybdenum disulfide, has been developed. According to the results of comparative tribotechnical tests, it was found that the intensity of linear wear of the material filled with MoS2 is 3 times, and Fe3O4 - 1.6 times lower than that of the coatings without filler. Based on the technology of microplasma electrolytic oxidation, an original technology has been developed for obtaining mineral-ceramic material, which is a matrix of aluminum oxide and dispersed diamond inclusions. Abrasive wheels made from this material have a consistently high volumetric cutting ability, 1.5-3.5 times higher than the traditional analogues and are characterized by high diamond retention. The possibilities of microplasma oxidation have not yet been fully explored, the most promising direction being the creation of nanostructured coatings for a specific technological task.

The practical interest in passive magnetic bearings is due to the fact that they are not subject to wear and have insignificant dissipative energy losses. However, when the magnets are heated during operation, a reversible and irreversible decrease in the residual magnetization occurs and, consequently, the force of interaction between them changes. The thermal properties of passive magnetic bearings are adversely affected by the large demagnetizing fields from the coupled magnets. To predict the performance of passive magnetic bearings with regard to external temperature, an assessment of temperature changes in the bearing capacity of bearings with optimally shaped magnets is necessary. The optimum magnets were considered to be those with sizes, whose interaction force, reduced to a single volume of magnetic material, was the maximum. A magnetic system of two cylindrical magnets with equal radii and heights located coaxially or with some radial displacement was considered. The studies were carried out on cylindrical magnets made of SmCo5 alloy, capable of maintaining magnetically hard properties at temperatures up to 250°C. It was confirmed that irreversible changes in the magnetic force for bearings with optimally sized magnets are close to each other. The destabilizing (radial) magnetic force at small radial displacements of one of the magnets also irreversibly decreased. A temperature of 250°C defines the upper limit of the temperature range for the normal operation of magnetic bearings with SmCo5 magnets. It was found that as a result of the action of a demagnetizing field on magnets during heating, they develop a significant inhomogeneity of magnetization over the volume. After demagnetization of the magnets kept at a temperature of 260 °C, the force of their interaction reaches only 85 - 90% of the original, which is associated with microstructural changes in the magnets. Theoretically and experimentally, the numerical values of the temperature coefficients of changes in the bearing capacity and stiffness of bearings are determined.

The paper presents the results of theoretical and experimental studies of the magnetic properties of magnetic lubricating oils. It shows oil magnetization curves in the initial state and after tests in the boundary friction mode. Oil properties were measured by an original magnetometer with Hall sensors. It has been established that triboeffects change oil composition and structure and decrease its magnetization. The results will help determine the optimal operating conditions of magnetic oils while maintaining their magnetic and lubricating properties.

The article is devoted to the scientific approach with the help of computer-aided design tools for modeling the processes of interaction of tillage tools with soil. The article has an applied character, which is expressed in the fact that the method of computer-aided design in Mathcad using software CAD COMPASS 3D has been used. The analyses of expressions in the form of three-dimensional graphs are widely presented and their detailed review is given, which can be used to perform the improvement of the design of units that perform the main treatment of the soil with a turnover of a layer. As a result of the work done, there was obtained a combined plowshare with additional flat-cutting working bodies, there was made a matrix of experiment planning, there was obtained a graph of the dependence of the width grip of the flat-cutting razor on the speed of the arable unit. There were substantiated the factors of influence on performance as a result of using the planning of the two-factor experiment due to the orthogonal plan, there were determined the optimal settings of the operation modes of the plowshare.