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The long-term stability of well-known TVO sensors before and after gamma irradiation was investigated during almost 17 years. Five of six sensors, calibrated in the temperature range from 3 to 300 K, were selected according to a requirement of their relative accuracy ΔT/T ≤ ± 0.25% at the cryogenic temperature range. Long-term stability measurements made 7.5 years after calibration are in good agreement with this value at 293, 77.3, and 4.2 K. Then these sensors and the sixth sensor, taken as the “worst” one for comparison, were irradiated by the 60Co gamma source at room temperature up to the total dose of about 1 MGy. Noticeable relative temperature shifts (more than ± 0.25%) are revealed for all the sensors after irradiation, and this fact is explained based on the model of structural changes in the volume of the sensitive element. Post-irradiation measurements carried out during 9 years at 293, 77.3, and 4.2 K indicate good stability of the sensors after irradiation.

This paper studies the influence of lattice and shell type architecture on the mechanical properties of biodegradable polymer scaffolds (cellular matrices) designed to create structures for bone tissue engineering. Varying the topology of nodal connections makes it possible to control the relative rigidity of the metamaterial in the range from 0.004 to 0.123. It is shown to be possible to create permeable scaffolds using thermally extruded 3D printing based on polymers of different elasticities—polylactide and polyurethane. The use of “unit cells” of various types allows fabricating structures such as shells based on polylactide with a compressive strength of 1.5 to 19.7 MPa. Shells with a cubic type architecture based on polyurethane can be almost reversibly deformed at values of deformation of more than 50%. The developed approaches for obtaining polymer metamaterials and modifying their surface with calcium phosphate layer using an artificial interstitial fluid can increase the hydrophilicity of materials.

Calcium phosphate powder were synthesized from aqueous solutions of calcium lactate Ca(C3H5O3)2 and ammonium hydrophosphate (NH4)2HPO4 at a Ca/P = 1 molar ratio. According to the XRD data, the phase composition of as-synthesized powder consisted of brushite CaHPO4 ⋅ 2H2O and hydroxyapatite Ca10(PO4)6(OH)2. After heat treatment at 350–600°C, the powder was colored dark brown owing to the destruction of the by-product of the reaction. The composition of the powder heat-treated at 350°C included monetite CaHPO4 and hydroxyapatite Ca10(PO4)6(OH)2, and the powder heat-treated at 600°C consists of hydroxyapatite Ca10(PO4)6(OH)2 and γ-calcium pyrophosphate γ-Ca2P2O7. The phase composition of ceramic obtained from the synthesized powder after sintering at 1100°C consisted of β-calcium pyrophosphate β-Ca2P2O7 and β‑tricalcium phosphate β-Ca3(PO4)2. The colored after the heat treatment in a range of 350–600°C powders can be used as a starting for the molding of porous biocompatible calcium phosphate composite materials with the given geometry of the porous space by stereolithographic printing. The synthesized powder can be recommended for the development of biocompatible and biodegradable both ceramic composite materials and composites with polymer or inorganic matrix for bone implants.

Bone implants capable to create an electrical stimulus for bone tissue regeneration under the influence of an external magnetic field are considered. A promising method for generating local electric fields is the use of magnetoelectric (multiferroic) micro- and nanoparticles, being polarized under the action of an external magnetic field, creating electric fields comparable in amplitude to endogenous ones. Of practical interest are composite magnetoelectric particles consisting of a ferrimagnetic core and a piezoelectric shell brought into close mechanical contact. The paper presents the results of modeling the magnetoelectric effect in a composite particle, fabrication of composite particles with cobalt ferrite as a magnetostrictive core, and considers the issues of the chemical interaction of phases.

The article presents studies carried out on a group of rats in order to determine the influence of the morphological characteristics of animals on the conduct of general inhalation anesthesia. It was found that if the rules for the preparation of animals, dosage of drugs (due to the physiological characteristics of rats), as well as proper care of animals after anesthesia are observed, the risk of complications, up to death, is reduced to a minimum.

The effect of atorvastatin on the immune system and lipid metabolism after 24-week treatment of patients with chronic myocarditis is considered. Statins have been found to improve the clinical course of heart failure with a preserved ejection fraction in patients with myocarditis: they reduce the functional class of heart failure, improve the systolic function of the heart and its arrhythmogenic potential. Despite the large amount of conflicting data in the field of statin use in heart failure, one can think about the possible influence of molecular differences in statins on their pharmacological and pleiotropic effects. In particular, atorvastatin, which has lipophilic properties, is able to penetrate cardiomyocytes in contrast to hydrophilic rosuvastatin, which may partially explain the positive cardiac effects of atorvastatin in patients with heart failure with a preserved ejection fraction. The probable basis for the positive effect of atorvastatin on morphofunctional parameters in heart failure is its positive pleiotropic effects associated with a decrease in рro-inflammatory immune markers and subsequent leveling of negative neurohumoral activation. An additional mechanism that caused the positive effect of atorvastatin on the clinical course of heart failure can be considered a factor of preservation of systolic function of the left ventricle.

The review covers problems related to development and application of a new type of “smart” medical materials, mainly, for regeneration of bone tissue that are capable of creating additional stimuli influencing the regeneration process. Application of ferroelectric and magnetoelastic materials is discussed, including their use as sensors and actuators. Physical and materials science principles of development, along with examples of using composite magnetoelectric materials of the piezoelectric/magnetoelastic type as magnetically controlled scaffolds creating local electric fields, are analyzed.

Technologies for the 3D printing of metallic powders are being increasingly extensively used around the world as alternatives to casting and machining to manufacture components of complex shapes and prototypes. Silicon-alloyed aluminum alloys are the most widely used materials in the selective laser melting technologies, which is caused by the price of these alloys and their high manufacturability for the layer-by-layer fused deposition, owing to their low susceptibility to hot cracking under thermal and shrinkage stresses. High rates of cooling the melt facilitate the formation in the material of ultradispersed silicon-containing phases, which results in increased strength. In the article, exemplified by two cast alloys (AK7ch and AK9ch), the speeds of the process of building up the products by the selective laser melting technology have been determined at a laser-beam power of 300 and 325 W and an energy density within the range 89–32 J/mm3. It is shown that, for the AK9ch alloy, lower porosity values are achieved within the investigated energy density range when compared with the AK7ch alloy and better mechanical properties of the alloy with a higher silicon content are achieved within the range of lower laser-beam energy densities than for the alloy with a lower silicon content. The mechanical properties of the materials produced under the optimal selective laser melting conditions comply with the most stringent requirements for the mechanical characteristics of the castings of the AK7ch alloy upon heat treatment.

Ceramic in the system Ca2P2O7–Ca(PO3)2 was obtained by firing cement stone fabricated from a powder mixture which included β-tricalcium phosphate β-Ca3(PO4)2 and monocalcium phosphate monohydrate Ca(H2PO4)2 ∙ H2O. The molar ratio Ca/P of the initial powder mixtures was set as Ca/P ≤ 1. X-ray phase analysis shows all ceramic samples after firing at 1000°C to include β-calcium pyrophosphate β-Ca2P2O7, and a sample of the ceramic made from a powder mixture with the maximum content of monocalcium phosphate monohydrate Ca(H2PO4)2 ∙ H2O also contained β-calcium polyphosphate β-Ca(PO3)2. The obtained calcium phosphate ceramic with reduced firing temperature can be used to develop a resorbable matrix for tissue engineering structures.

Calcium phosphate ceramics, with the phase composition represented by β-calcium pyrophosphate β-Ca2P2O7, was obtained from a powder mixture of calcium hydroxyapatite Ca10(PO4)6(OH)2, monocalcium phosphate monohydrate Ca(H2PO4)2 · H2O, and sodium hydrogen phosphate Na2HPO4. The powder mixture was preliminarily homogenized in acetone using a planetary mill. This treatment resulted in the chemical reaction between the starting components to form monetite, calcium hydrogen phosphate CaHPO4 (precursor of calcium pyrophosphate Ca2P2O7). According to the XRD data, sodium hydrogen phosphate Na2HPO4 when present in an amount of 5 wt % in the starting mixture had no effect on the phase composition of the powder after homogenization and of the ceramics after annealing. Sodium pyrophosphate Na4P2O7 formed from sodium hydrogen phosphate Na2HPO4 as a result of thermal conversion had a significant effect on sintering mechanism and the microstructure of the ceramics. A ceramics with a low sintering temperature based on β-calcium pyrophosphate β-Ca2P2O7 was obtained for the first time from a powder system, upon preparation of which under mechanical activation conditions homogenization of components and synthesis of the main crystal phase precursor were combined.

The influence of modification of heat-resistant nickel-based alloys on the crystallization kinetics of alloys was established by the methods of thermal analysis. This effect is expressed in the increase in solidus temperature and, as a consequence, narrowing the crystallization range of the alloy, the increase in the growth rate of a solid solution, and change in the temperature of precipitation of eutectic and strengthening phases. As a result, the use of modification with refractory particles makes it possible to exert an additional effect on the structure and properties of nickel-based alloys without additional heat treatment

Double calcium’ammonium pyrophosphate monohydrate Ca(NH4)2P2O7•H2O was synthesized as a result of the interaction of calcium carbonate, an aqueous solution containing pyrophosphoric and lactic acids, and ammonia. The synthesized powder turned black after the thermal treatment in a range of 500—700 °C due to amorphous carbon, which is a product of the destruction of the organic nature components present in the prepared powder. After the thermal treatment at 500 °C, the powder is amorphous to X-rays. The phase composition of the powder after the thermal treatment at 600 °C is presented by β-calcium polyphosphate β-Са(PO3)2, while β-calcium polyphosphate β-Ca(PO3)2 and tromelite Ca4P6О19 are observed after the thermal treatment at 700 °C. The calcium phosphate powder colored due to presence of amorphous carbon can be used as a photocured suspension component that increases the resolution in stereolithographic printing of pre-ceramic semifinished products with a specified geometry of the pore space of calcium phosphate ceramic matrices. The synthesized powder of double calcium’ammonium pyrophosphate monohydrate Ca(NH4)2P2O7•H2O can be applied as a precursor of biocompatible phases for the fabrication of calcium phosphate ceramics used in medicine for the treatment of bone tissue defects.

When mining hard coal the underground method is prevailed. This method provides a higher quality of the mineral. Methane emissions occur in coal mines during the development of gasbearing seams. These emissions are the reason for the formation of an explosive mixture when mixed with mine air, and also contribute to the spontaneous combustion of coal. Methane alarms are used to monitor the mine atmosphere. Thermocatalytic sensor is the main element of such a gas analyzer. The sensor is placed in a breathable housing. This body is called a flame arrester. This article discusses the possibility of replacing the material used for the manufacture of a flame arrester. The basis of the existing material is nickel powder. It is proposed to replace it with a cermet bond. The composition of the ceramic material of the part is developed by the author and presented in the article. Replacement of material will lead to a significant reduction in the cost of the part and simplification of the manufacturing technology

Possible extreme fluctuations of sea level in the area of the Akkuyu nuclear power plant induced by tsunami, wind, waves, and tides are discussed. The probability characteristics of dangerous sea-level rise in the area are estimated using hydrodynamic modeling and historical data.

Ceramic samples based on b-calcium pyrophosphate b-Ca2P2O7 were prepared using firing at 900, 1000, and 1100 oC from powders of g-calcium pyrophosphate g-Ca2P2O7 with preset molar ratios Ca/P=1; 0,975 and 0,95. To prepare powders of g-calcium pyrophosphate g-Ca2P2O7 with preset molar ratio Ca/P=1; 0,975 and 0,95 powder mixtures based on calcium lactate pentahydrate Ca(C3H5O3)2⋅5H2O and, monocalcium phosphate monohydrate Ca(H2PO4)2⋅H2O were treated in an aqua medium in mechanical activation conditions, dried, disaggregated in acetone, and heat-treated at 600 oC. The phase composition of powder mixtures after treatment if planetary mill in aqua medium included both brushite CaHPO4⋅2H2O or monetite CaHPO4, and starting salts. The phase composition of all powder mixtures after disaggregation in acetone in planetary mill included monetite CaHPO4 and starting salts. After heat treatment at 600 oC according to the XRD data phase composition of all powder mixtures was presented by g-calcium pyrophosphate g-Ca2P2O7. The grain size of ceramics increased both with the growth of firing temperature and with decreasing of molar ratio Ca/P of powder mixtures. Calcium polyphosphate (t melt =960–968 oC) formed from monocalcium phosphate monohydrate Ca(H2PO4)2⋅H2O acted like a liquid phase sintering additive. It was confirmed by tests in vitro, that prepared ceramic materials with preset molar ratio Ca/P=1; 0,975 and 0,95 and phase composition presented by b-calcium pyrophosphate b-Ca2P2O7 according to XRD data were biocompatible and could maintain bone cells proliferation.

Powder mixture with given molar ratio Ca/P = 1.67 consisting of brushite (calcium hydrophosphate dihydrate) CaHPO4·2H2O, calcium oxalate monohydrate CaC2O4·H2O in form of whewellite and weddellite and some quantity of quasi-amorphous phase was obtained as a result of the interaction of hydroxyapatite powder Ca10(PO4)6(OH)2 with an aqueous solution of oxalic acid H2C2O4 at a molar ratio of Ca10(PO4)6(OH)2/H2C2O4 = 1:4 under mechanical activation conditions. This powder mixture was used to produce microporous monophase ceramics based on hydroxyapatite Ca10(PO4)6(OH)2 with aperient density of 1.25 g/cm3 after firing at 1200 oC. Microporosity of sintered ceramics was formed due to presence of particles with plate-like morphology, restraining shrinkage during sintering. Microporous ceramics based on hydroxyapatite Ca10(PO4)6(OH)2 with roughness of the surface as a consequence of the created microporosity can be recommended as a biocompatible material for the bone defects treatment and as a substrate for bone cell cultivation.

Due to a significant influence of strontium (Sr) on bone regeneration, Sr substituted beta-tricalcium phosphate (Sr-TCP) cement is prepared and investigated by short- and long-term time-resolved techniques. For short-term investigations, energy-dispersive X-ray diffraction, infrared spectroscopy, and, for the first time, terahertz time-domain spectroscopy techniques are applied. For long-term time-resolved studies, angular dispersive X-ray diffraction, scanning electron microscopy, mechanical tests, and behavior in Ringer solution are carried out. After 45 min of the cement setting, the Sr-TCP phase is no longer detectable. During this time period, an appearance and constant increase of the final brushite phase are registered. The compressive strength of the Sr-TCP cement increases from 4.5 MPa after 2 h of setting and reaches maximum at 13.3 MPa after 21 d. After cement soaking for 21 d in Ringer solution, apatite final product, with an admixture of brushite and TCP phases is detected. The cytotoxicity aspects of the prepared cement are investigated using NCTC 3T3 fibroblast cell line, and the cytocompatibility-by human dental pulp mesenchymal stem cells. The obtained results allow to conclude that the developed Sr-TCP cement is promising for biomedical applications for bone tissue.