bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhancement of Crack Resistance of Phthalonitrile-Based Carbon Fiber Reinforced Plastics by Introducing Polyamide Nonwoven Materials
Authors: Kutovaya I. V. , Poliakova D. I. , Erdni-Goryaev E. M. , Lipatov Ya. V. , Afanaseva E. S. , Morozov O. S. , Babkin A. V. , Kepman A. V.
Published: April 2024

The effect of introduction of polyamide nonwoven materials on the thermal and mechanical properties of polymer composite materials based on phthalonitriles and a carbon fabric is studied. It is shown that the addition of 3 wt % of polyamide nonwoven material causes a 44% increase in the specific work of delamination. At room temperature elastic mechanical characteristics, such as compressive strength and compressive modulus, for the composite modified with the nonwoven material increase by 12 and 100%, respectively. According to dynamic mechanical analysis, upon reaching 169°C the melting of polyamide occurs; however, there remains the possibility to use the composites above this temperature, as confirmed by mechanical tests performed at 200°C.
Silicones in Cosmetics
Authors: Ivanova E. V. , Minyaylo E. O. , Temnikov M. N. , Mukhtorov L. G. , Atroshchenko Yu. M.
Published: April 2024

The structural diversity of organosilicon compounds used in decorative and care cosmetic products is studied. The unique physicochemical properties of silicones allowing their application as emollients, moisturizers, emulsifiers, film formers, viscosity regulators, and antistatic and binding agents are described. Mechanisms of action of various structure silicones, due to which organosilicon compounds are advantageously used to impart certain properties to cosmetic products, are demonstrated. A comparative analysis of the efficiency of silicones versus natural compounds serving similar functions in cosmetic products is performed. The issue of silicone safety for human health is considered.
Two-Photon Stereolithography—Optical Nanolithography
Authors: Zhiganshina E. R. , Arsenyev M. V. , Chesnokov S. A.
Published: April 2024

Free-radical photopolymerization has been widely used in additive technologies, in particular, stereolithography using single- and two-photon initiated polymerization. The single-photon stereolithography affords the objects with about 100 μm resolution. The two-photon stereolithography initiated with a femtosecond near-infrared laser can afford arbitrary 3D microstructures with ultrahigh resolution at micro- and nanoscale level (~100 nm). Herein each of the mentioned method and the mechanisms of single- and two-photon excitation are reviewed. The recent results on the components of the photopolymerizable resin as well as the approaches to decrease the size of the elements of objects and accelerate their formation have been generalizated and systematized.
On the Absence of Cyclic Structures in Branched Polystyrenes Synthesized by Living Three-Dimensional Radical Polymerization in the Medium of a Deteriorating Thermodynamic Quality Solvent
Authors: Kurochkin S. A. , Makhonina L. I. , Perepelitsina E. O. , Bubnova M. L. , Berezin M. P. , Grachev V. P.
Published: April 2024

Branched polystyrenes are synthesized by the radical copolymerization of styrene and divinylbenzene with reversible inhibition (in the presence of 2,2,6,6-tetramethylpiperidine-1-oxyl) under deteriorating thermodynamic quality of the solvent. The resulting polymers are studied by size-exclusion chromatography combined with static light scattering, ozonolysis, NMR spectroscopy, and differential scanning calorimetry. The branched polymers synthesized by living radical polymerization are characterized by lower intrinsic viscosity values than their linear analogs. Kuhn–Mark–Houwink parameters for these polymers in a tetrahydrofuran solution (а = 0.29) confirm the nonlinear architecture of macromolecules and a high content of pendant double bonds comparable in the order of magnitude with their theoretical content in the absence of the cyclization reaction indicate their branched structure. The glass transition temperature of the branched polystyrenes is 20–35°С lower than the glass transition temperature of the linear polystyrene.
Features of Methyl Methacrylate Polymerization Mediated by Methylene Blue and Ethyl 2-Bromoisobutyrate under Photoirradiation Conditions
Authors: Lizyakina O. S. , Vaganova L. B. , Grishin D. F.
Published: April 2024

Using methyl methacrylate polymerization as an example, the features of polymer synthesis in the presence of the catalytic system [methylene blue + ethyl 2-bromoisobutyrate] at room temperature under visible light irradiation are investigated. The effect of polymerization conditions, including the light irradiation wavelength and various structure activators, on the monomer conversion and molecular weight characteristics of polymers is estimated. It is shown that polymerization can proceed in the controlled mode under mild temperature conditions according to the atom transfer mechanism (Metal Free Atom Transfer Radical Polymerization) to high conversions at low photocatalyst concentrations.
Polyampholite–Metal Complexes for Catalytic Processes
Authors: Lipin V. A. , Poshvina T. A. , Fedorova K. A. , Fadin A. F. , Maltseva N. V. , Vishnevskaya T. A.
Published: April 2024

Polyampholyte–metal complexes based on polyacrylic acid; the aliphatic diamines ethylenediamine, 1,3-diaminopropane, and 1,4-diaminobutane; and Cu2+ was obtained by reacting aqueous solutions of polyampholytes and CuSO4. Using the method of simultaneous thermal analysis, it was found that the thermal degradation of the complexes occurs in three steps. The activation energy of thermal degradation of the polyampholyte–metal complexes is 22–99 kJ/mol. It was established by X-ray diffraction analysis that the products of thermal degradation of polyampholyte–metal complexes are heterogeneous systems composed of CuO and Cu2O phases, while catalysts based on them are heterogeneous systems consisting of Al2O3 and CuO phases. The size distribution of catalyst pores showed that the volume of pores with a diameter of less than 773 nm was 0.80–0.83 cm3/g, the specific surface area was 349–351 m2/g, and the predominant equivalent pore diameter was 6.2–6.3 nm. The mechanical crushing strength of catalyst pellets was found to be 7.1–7.3 MPa. In the process of CO oxidation to CO2, the catalyst began to exhibit its activity at 180–187°C; the complete conversion of CO in the oxidation reaction was achieved at 280–286°C. The performance of the obtained catalysts was 2.7–2.8 times higher than that of a reference sample.
Special Features of Multiple Luminescence of the Dyad Containing Imidazole and Coumarin Fragments in Photocured Network Acrylate Polymers
Authors: Matveeva I. A. , Shashkova V. T. , Lyubimov A. V. , Lyubimova G. V. , Kol’tsova L. S. , Shienok A. I. , Zaichenko N. L.
Published: April 2024

The conditions to prepare luminescent acrylate polymers containing the organic dyad, molecule of which combines two different emitting fragments, hydroxyl-substituted 2,4,5–triarylimidazole and 8-azomethine-7-hydroxycoumarine moieties, via photocuring have been optimized. The effect of the nature of the photocured network acrylate polymers on luminescent properties of the dyad has been investigated. The prepared aliphatic network polymers have exhibited independent fluorescence of both molecule fragments, dependent on the excitation wavelength. At the same time, the aromatic network polymers and the aliphatic network polymers containing ether links have revealed only the imidazole fragment fluorescence. The fluorescence nature has been stronger dependent on the polymer repeat unit structure and the content of the aromatic fragments in the polymer matrix than on the presence of the hydroxyl groups in the polymer. It has been shown that the emission of the imidazole fragment of the dyad in the aliphatic network polymers depends on the internode distance and conditional polarity of the medium.
Synthesis of Aromatic Polyamidines by the [2+2]-Cycloaddition Reaction
Authors: Mognonov D. M. , Khakhinov V. V. , Tkacheva N. I. , Morozov S. V.
Published: April 2024

Aromatic polyamidines based on 4,4′-diphenylmethane diisocyanate and bisamides have been synthesized and studied. The one-step reaction of bisamides with diazocyanate according to the [2+2]-cycloaddition mechanism includes a concerted process of the formation of two new σ-bonds in the transition state. The formation of polyamidine occurs as a result of decarboxylation, which completes this reaction. Due to the availability of starting compounds, ease of synthesis, good solubility, and high heat resistance and thermal stability of the resulting polymers, there are wide opportunities for producing new materials by conventional industrial processes. Polyamidines have a sufficiently large set of important technological properties, which suggest their greater potential in relation to applied problems. The resulting film materials and glass-reinforced plastics based on polyamidines show high mechanical properties that are not inferior to those of materials made from commercial polyamides and polybenzimidazoles.
High-Performance Catalysts Based on Hybrid Salicylaldarylimine Complexes of Titanium(IV) Dichloride for the Synthesis of Ultrahigh Molecular Weight Polyethylene with Unentangled Macromolecules
Authors: Oleynik I. V. , Shundrina I. K. , Oleynik I. I.
Published: April 2024

The features of ethylene polymerization in the presence of dichloridobis(salicylaldaryliminato)titanium(IV) complexes containing a 4-allyloxy-2,3,5,6-tetrafluorophenylimino group, namely, {2‑[(4-CH2=CH-CH2O)C6F4N=CH]-6-R1-4-R2-C6H2O}2TiCl2 (R1 = t-Bu, CMe2(Ph); R2 = H, Me, OMe, t-Bu, CMe2(Ph), Cl, Br) in the presence of methylalumoxane, have been studied. All the complexes exhibit high catalytic activity (27.8×106 гПЭ∙мольTi‐ 1∙МПаC2H4-1∙ч‐ 1)) in the temperature range of 10‒60°C and form powdered ultrahigh molecular weight polyethylene (UHMWPE) (M = (4.4–16.0) × 106 g/mol) with a low number of intermolecular entanglements. It has been shown that during polymerization, the complexes are immobilized on UHMWPE macromolecules.
Effect of Characteristics of Polymer Microgel Catalysts on the Efficiency of Interfacial Catalysis
Authors: Anakhov M. V. , Gumerov R. A. , Potemkin I. I.
Published: April 2024

Effect of the architecture and composition of a hydrophilic microgel catalyst on the rate of interfacial catalytic reaction proceeding at the water/oil interface and involving reagents dissolved in opposite phases is studied using dissipative particle dynamics simulations. It is shown that a decrease in the crosslinking density of the microgel, the existence of a cavity in its architecture, an increase in its size, the incorporation the hydrophobic comonomers into a macromolecule, and a rise in the degree of solubility of a network macromolecule in oil contribute to acceleration of the catalytic reaction due to increase of the area of the water–oil–microgel contact and growth of the number of contacts between reagents and catalytic groups. However, in the case of amphiphilic microgels and microgels soluble in both phases, the acceleration of the reaction is restrained by a low rate of reagents diffusion and a rapid reduction in the concentration of reagents in the vicinity of catalytic sites.
Polytope 240-Based Rod Structures Made of Tetrahedral Atoms: Comparison with Structures Obtained Using a Modular Design Method
Authors: Zheligovskaya E. A.
Published: April 2024

Some rod structures consisting of tetrahedral atoms and differing in symmetry are considered. The structures are obtained as a stereographic projection of polytope 240 vertices into three-dimensional Euclidean space when the polytope rolls along a straight line belonging to this space. The axes of the rod structures are the projections of great circles of a three-dimensional sphere containing the polytope 240 vertices. It has been shown that the rod structures obtained earlier by modular design are topologically equivalent to those considered in this paper, but they have a changed symmetry. Three possible conformations following from the results of this work are presented for a CnH2n hydrocarbon chain with close packing of atoms, conservation of the tetrahedral coordination of carbon atoms, and noncrystallographic symmetry.
Adsorption of Random Copolymer on a Chemically Heterogeneous Periodic Stripe-Patterned Surface
Authors: Ivanova A. S. , Polotsky A. A.
Published: April 2024

The adsorption of a single random copolymer chain containing correlations in a sequence on the chemically heterogeneous periodic surface with the alternating striped texture is studied theoretically. The problem is solved within the framework of a partially directed walk polymer model in three dimensions using the generating functions approach and the annealed disorder approximation for averaging over the ensemble of random sequences of units in the copolymer. Dependences of the adsorption transition point on the composition of the random copolymer and the degree of correlation in the random sequence of units for various periodic surfaces are presented. It is shown that for compositionally symmetric and weakly symmetric surfaces there is the optimal composition of the random copolymer and the degree of correlation in the sequence of units, at which the inverse temperature corresponding to the adsorption transition point has a local minimum. In the case of the compositionally symmetric surface, the “optimal” random copolymer is also symmetric in composition. For surfaces with a pronounced composition asymmetry the best adsorbent is a homopolymer complementary to sites that prevail on the surface. The degree of asymmetry range, in which the dependence of the inverse transition temperature on the copolymer composition and the correlation parameter exhibits the local minimum, is fairly narrow.
Diblock Copolymer Melt in an Electric Field: Stability of the Homogeneous State in the Random Phase Approximation
Authors: Kriksin Yu. A. , Kudryavtsev Ya. V,
Published: April 2024

The contribution of I.Ya. Erukhimovich (1947–2022) to the creation of the theory of microphase separation in di- and triblock copolymers has been briefly analyzed. His matrix method of calculating correlation functions for multicomponent polymer systems has been applied to find the spinodal of a diblock copolymer melt in a static electric field. It has been strictly shown that for a linear dependence of local dielectric constant of the copolymer on the order parameter the spinodal condition remains the same as in the absence of the electric field. The correction to the critical value of the Flory‒Huggins parameter has been calculated for more general case of the quadratic dependence.
Study of the Effect of Nonselective Organic Solvent Nature on the Self-Organization of Amphiphilic Block Copolymers of D,L-Lactide and Ethylene Oxide in Aqueous Solution
Authors: Kuznetsova E. V. , Shirokova E. M. , Puchkova Yu. A. , Yastremsky E. V. , Chvalun S. N.
Published: April 2024

The self-organization of biocompatible amphiphilic block copolymers of D,L-lactide and ethylene oxide with various hydrophobic poly(D,L-lactide) block length in aqueous media has been investigated. It has been shown that the nature of nonselective organic solvent has a considerable effect on the size, size polydispersity, and morphology of micelles of a block copolymer with a long poly(D,L-lactide) block. To elucidate the dependence of properties of block copolymer micelles on the common organic solvent type (acetone, tetrahydrofuran, N,N-dimethylformamide, and acetonitrile) various parameters of the used solvents have been estimated, and correlation between the Flory–Huggins coefficient and the surface tension between the hydrophobic block and the nonselective organic solvent and the parameters of micellar structures has been found.
Modern Approaches to Obtaining Organofunctional Silsesquioxanes
Authors: Bredov N. S. , Kireev V. V. , Polyakov V. A. , Sokol’skaya I. V. , Esin A. S.
Published: April 2024

Modern research in the field of synthesis of organofunctional oligosilsesquioxanes is considered. Relationships between the composition and structure of oligomeric organosilsesquioxanes and the conditions for their formation during the hydrolytic and acidohydrolytic polycondensation of organotrialkoxysilanes containing various functionalities, such as methacrylic, aminopropyl, carboxyl, and cyclotriphosphazene groups, in organic radicals bonded to silicon atoms are shown. A comparative analysis of approaches to the synthesis of organofunctional incompletely condensed oligosilsesquioxanes has been carried out.
One-Step Synthesis of Monosilicon-Substituted Norbornenes with Siloxane and Aryl Fragments and Their Polymerization
Authors: Guseva M. A. , Lezhnin P. P. , Alentiev D. A. , Zaitsev K. V. , Bermeshev M. V.
Published: April 2024

Three monosilicon-substituted norbornene monomers with phenyl and siloxane groups at the silicon atom are synthesized by the one-step hydrosilylation of 2,5-norbornadiene. The proposed method allows the synthesis of monomers with a higher content of polymerization-reactive exo-isomer in products compared with similar adducts formed by the Diels‒Аlder reaction. The synthesized monomers show high reactivity in both metathesis polymerization and addition polymerization more sensitive to the substituent volume. Using these monomers two series of high molecular weight silicon-substituted polynorbornenes are prepared which are found to be glassy and thermally stable polymers.
Mechanochemical Interaction of Phenylboronic Acid with Polyphenylsilsesquioxane and a Hydroxy(phenyl)siloxane Oligomer
Authors: Libanov V. V. , Kapustina A. A. , Shapkin N. P.
Published: April 2024

The interaction of phenylboronic acid with polyphenylsiloxane and a hydroxy(phenyl)siloxane oligomer has been studied. For the first time, phenylboronic acid was used as a starting material for the production of polyboronphenylsiloxanes under conditions of mechanochemical activation. It has been established that the main side processes induced by activation are abstraction of the phenyl substituent from the boron atom, formation of biphenyl, and trimerization of phenylboronic acid. Since boron compounds (including phenylboronic acid) have biological activity, their introduction into the polymer chain will make it possible to obtain materials with useful properties. For example, boron-containing polymers can be used as coatings to protect against insect vectors of various diseases. The work is fundamental in nature and contributes to revealing and understanding the mechanisms of mechanochemical modification of organosilicon polymers.
Practical Application of Selected Functional Organosilicone Polymers
Authors: Nedel’kin V. I. , Nedel’kin A. V. , Izmailov B. A. , Zachernyuk A. B. , Solov’eva E. N. , Zachernyuk B. A.
Published: April 2024

The available information concerning the preparation and properties of modifying siloxane coatings on the surface of fibrous materials, as well as a number of other functional silicone polymers for hydrophobization of fibers, textiles, leather, building materials, creation of adhesive compositions, and other practically valuable silicone products has been generalized.
Novel Approach to the Synthesis of Bithiophenesilane Dendrimers with Efficient Intramolecular Energy Transfer
Authors: Skorotetskii M. S. , Borshchev O. V. , Kleimyuk E. A. , Svidchenko E. A. , Surin N. M. , Ponomarenko S. A.
Published: April 2024

A synthetic scheme allowing the preparation of nanostructured organosilicon luminophores of branched or dendritic structure with up to 18 bithiophenesilane donor fragments and one central acceptor fragment has been elaborated. This universal scheme has been successfully upscaled to 20 g of the product, and its efficiency has been verified by the synthesis of two earlier unknown bithiophenesilane dendrimers with dense molecular shell and the central acceptor fragment, 1,4-bis(5-phenylthienyl-2-yl)benzene. The synthesis of more branched dendrimers under the Suzuki reaction conditions has led to the formation of the side products with the rupture of the Si–C(thiophene) bond, not typical of the synthesis of analogous compounds with lower branching degree under the same conditions.
Silicone Resin Applications for Heat-Resistant Coatings: A Review
Authors: Hanqi Qian Hanqi Qian , Jiang Bo
Published: April 2024

Silicone resins, which exhibits excellent heat-resistance, chemical stability and adhesion, are indispensable components in high temperature resistance coatings. Herein, we summarize a comprehensive survey of developments on heat-resistant silicone-based coatings. The influence of heat-resistant of modifying silicone resin chain segment, such as main chain modification and side main modification are discussed. Then, the physical and chemical properties of inorganic fillers combined with silicone resins are summarized for the aim of ceramization and further improving the degree of heat-resistant. Finally, the challenges and future opportunities of heat resistance coatings based on silicone resins are considered.
Effects of γ-aminobutyric acid (GABA) intake in combination with exercise on muscle strength in humans with decreased mobility: a randomized, double-blind, placebo-controlled, parallel-group study
Authors: Uehara Eriko , Hokazono Hideki , Tomonaga Akihito , Fukagawa Mitsuhiko
Published: April 2024

Background: Aging-related declines in skeletal muscle mass, muscle strength, and physical function are related to instability, falls, and frailty in older people, resulting in the need for nursing care.
Objective: To investigate the effect of oral γ-aminobutyric acid (GABA) intake and exercise on muscle parameters in healthy subjects whose muscle strength is beginning to decline with age.
Methods: A randomized, double-blind, placebo-controlled, parallel-group comparative study was conducted. Fifty subjects (over 40 years old) were randomly divided into the GABA (100 mg/day) or placebo food intake group. Subjects orally consumed the respective study substance every day for 12 weeks. They performed daily “locomotion training” as devised by the Japanese Orthopedic Society. Muscle mass, fat mass, and knee extension muscle strength were measured.
Results: The two groups had no significant differences in muscle and fat mass. Compared with the placebo food group, the GABA group showed a significant improvement in knee extension muscle strength in the left and right legs at pre-dose Week 0 (at Week 6, p = 0.02). In post hoc subgroup analysis by sex, when compared with the placebo food intake group, the GABA food intake group showed significant improvement in knee extension muscle strength of the right leg at Weeks 6 (p = 0.001) and 12 (p = 0.007), the left leg at Week 6 (p = 0.02), the stronger of the left and right legs at pre-dose Week 0 (at Week 6, p = 0.001), and the weaker of the left and right legs at pre-dose Week 0 (at Week 12, p = 0.013) in males.
Conclusions: These results suggest that GABA intake combined with daily exercise is effective for maintaining knee extension muscle strength, which decreases with age. Furthermore, there were no safety issues with the intake of GABA-containing food during this study.
Trial registration: UMIN-CTR: UMIN000050152.
Keywords: γ-Aminobutyric acid, GABA, Muscle mass, Knee extension muscle strength, Aging
Physical and mechanical properties of meta-halloysite-based geopolymer mortars
Authors: Owsiak Zdzisława , Szczykutowicz Katarzyna
Published: April 2024

Geopolymers are amorphous materials produced by the polymerisation reaction between an aluminosilicate precursor and an alkaline reagent or by activation with phosphoric acid. The aluminosilicate raw material used in the manufacture of geopolymers an be industrial waste, such as fly ash or volcanic ash, blastfurnace slag, or it can be obtained from natural raw materials, such as metakaolin and meta-halloysite. The work aimed to select the composition of an activator for the production of meta-halloysite geopolymers with optimum physico-mechanical properties such as specific and bulk density, porosity, weight, and bulk absorption, as well as flexural and compressive strength. A two-factor experimental design was employed to determine the composition of the alkaline activator for geopolymer mortars, with sodium hydroxide solution molar concentration and sodium silicate to NaOH ratio as variables. Research has shown that increasing the amount of sodium silicate relative to the mass of a 12M NaOH solution in the activator solution improves the compressive strength of geopolymers by 36.8%, while an increase in flexural strength of 14.2% was achieved. As the molar concentration of caustic soda in the activator solution increases from 19.0 to 24.5%, the porosity of geopolymer mortars decreases. The reduction in the ratio of water glass to sodium hydroxide and the reduction in the molar concentration of NaOH increases the mass and volume water absorption of the mortar. Further studies is necessary to determine the optimal mixture of metahalloysite geopolymer, taking into account its functional properties and durability.
About Measuring the Stress Intensity Factor of Cracks in Curved, Brittle Shells
Authors: Sipos Andras A. , Cao Siwen
Published: April 2024

Most techniques of measuring the stress intensity factor (SIF) in the cracking process assume a crack in a planar medium. Currently, there is no effective approach for curved brittle shells, particularly for non-developable cases, i.e., shapes with non-vanishing Gaussian curvature. This paper introduces a novel approach to obtaining material properties related to fracture by experimentally observing weakly curved surfaces. Based on the DIC record of the displacement field around the crack tip, the truncated Williams expansion is fitted to the data adjusted according to the shallow shell equations. The convergence properties of the method are investigated by comparing experimental data of PMMA cylinders to theoretical and numerical predictions. The applicability of the technique to non-developable surfaces is verified. It is demonstrated that robust convergence requires the number of terms in the Williams expansion exceeding 6. For different geometries, the ratio of the data selection radius and the length of the crack should exceed 0.3.
Further development of innovative applications based on the inverse piezoelectric effect
Authors:   SHILAN LIGHTING ELECTRONIC CO., LTD CHINA, JINGTING ZHANG
Published: April 2024

As practice has shown, piezoelectric motors based on the principles of the inverse piezoelectric effect can become the basis for the latest automation systems and precision mechanics, as well as innovative lighting technology; The main interest of developers of our company is the possibility of building on the basis of the inverse piezoelectric effect of systems and configurations related to the systems of precision and small-sized stepper motors As the requirements for accuracy and weight reduction of such engines become stricter, including by reducing overall dimensions, more and more variants and technical solutions based on the complex application of special composite materials are offered as a base material for building elements and structures of such engines. In modern electronic equipment, especially mass-produced, it is extremely important to correctly determine the initial technical requirements for the product, which in the process of production and operation should allow to carry out innovative modification of the product without changing the fundamental basis of its design, circuit solutions and combination of materials and component parts.
Book 4. Building an ecosystem and infrastructure for smart confectionery production
Authors: Shchurenko Anastasiia
Published: April 2024

Innovative transformation of the ecosystem and infrastructure of a smart facility for the production of composite products into a developed combined supersystem with interconnected subsystems of online control in real time
Windows and doorways as part of the smart home ecosystem
Authors: Volkov Artem
Published: April 2024

Sliding and folding doors are a convenient option to close a doorway while maximizing the use of space. But not all accordions are equally reliable. There are many varieties of accordion doors on the market, from inexpensive interior doors to premium folding glass walls.
Book 3. Building an ecosystem and infrastructure for smart confectionery production
Authors: Shchurenko Anastasiia
Published: April 2024

Innovative transformation of the ecosystem and infrastructure of a smart facility for the production of composite products into a developed combined supersystem with interconnected subsystems of online control in real time
Analyzing the Challenges and Threats to the Petroleum Products Market in the Context of National Security
Authors:   Lviv Polytechnic National University, Donets Dmytro M. , Suruzhiu Ivan S. ,   Lviv Polytechnic National University, Pryima Petro B. ,   Lviv Polytechnic National University
Published: April 2024

In this work, based on the analysis of sources of information that are in the public domain, the major threats and challenges to the petroleum products market in the context of national security are identified. The concept of national security, its connection with other types of security and the place of the market of petroleum products in these relations are considered. A model of relations between the petroleum products market in the circle of national security has been built. For the petroleum products market of Ukraine, an analysis of factors that are threats and challenges both common to all countries and specific to Ukraine is carried out. The study identifies the main threats to the petroleum products market in Ukraine, including: the possibility of losing supplies due to the lack of medium-term and long-term contracts; intersection of interests of exporting and importing countries, which is reflected in their use of specific means of solving problems; blockade of ports, destruction of existing petroleum depots; the difficulty of creating a stock of petroleum products due to the vulnerability of warehouses or petroleum depots; problems with own production of petroleum products due to the destruction or damage of existing facilities for production of petroleum products and the vulnerability of places of extraction of raw materials for petroleum products; almost complete dependence on imports; political pressure on the petroleum products market both from exporting countries and domestic political pressure. The challenges to the market include the growth of the logistics leverage, the change in the preferences of buyers from gasoline in favor of diesel fuel and the rupture of previous logistic chains with the need to create new, as well as unplanned changes in transportation due to changes in the situation at the State borders. There is also a growing demand for the use of rail and sea transport for the supply of petroleum products to the markets of Ukraine. In this regard, an additional challenge is to pursue a reasonable pricing policy in these conditions in order to prevent a sharp increase in prices in the petroleum products market.
Correlación entre los resultados radiográficos y funcionales en pacientes adultos con fractura de radio distal tratadas de manera conservadora
Authors: Soriano Márquez Jorge Luis , Chávez Galván Carlos Rubén , Robles García José Antonio , Mazzini Berra Marco Paolo
Published: April 2024

Introducción: Las fracturas de radio distal en los pacientes adultos tienen una incidencia de 190-200/100,000 habitantes, éstas representan entre 26-46% de todas las fracturas observadas en un centro de atención primaria. La reducción anatómica de la fractura de radio distal suele presentar mejores resultados funcionales. Objetivo: Determinar la correlación entre los resultados radiográficos y funcionales de pacientes adultos con fractura de radio distal tratados conservadoramente. Material/Métodos: Se hizo revisión retrospectiva de registros de pacientes con fractura de radio distal tratados conservadoramente entre enero de 2015 y septiembre de 2020. Se realizaron mediciones radiográficas al inicio y al final del tratamiento, posteriormente se evaluaron los resultados funcionales con el cuestionario PRWE por vía telefónica, esto debido a la contingencia por la COVID-19. Para los datos generales de los pacientes se aplicaron medidas de tendencia central (media, mediana, moda) y para la comparación de grupos se utilizó la Prueba de chi-cuadrada, el análisis estadístico se realizó con el software Statistical Package for the Social Sciences (versión 19.0; SPSS, Inc., Chicago, IL, EE. UU.). Resultados: Se incluyó en el presente estudio a un total de 31 pacientes. Durante el seguimiento, 16 de ellos presentaron reducción aceptable y 15 reducción inaceptable. Se compararon los resultados de este grupo de pacientes con los resultados del cuestionario PRWE encontrando una correlación no estadísticamente significativa (p=0.765). Conclusión: No se encontró correlación significativa entre la reducción aceptable según los parámetros radiológicos y el resultado funcional en pacientes mayores de 18 años con fractura de radio distal tratados de forma conservadora.
 
Recepción: 08/09/2022Aprobación: 03/04/2024
Hubo una vez en medicina…Pandemias
Authors: Tello Esparza Adolfo
Published: April 2024

Recepción: 05/08/2023Aprobación: 07/02/2024
Caregiver Mental Health: A Crucial Piece of the Recovery Puzzle
Authors: Karikari Loretta
Published: April 2024

Caregiver Mental Health: A Crucial Piece of the Recovery Puzzle

The role of a caregiver is multifaceted, encompassing physical, emotional, and sometimes financial responsibilities. Caregivers, whether family members or friends, find themselves navigating various emotions, uncertainties, and responsibilities. The stressors of caregiving and the emotional burden erode their own mental well-being, creating a silent crisis that is left out of the caregiver narrative.

Studies reveal that caregivers grapple with anxiety, depression, and burnout. Poor mental health is well documented in the caregiving literature.

One crucial avenue for support lies in psychoeducational programs tailored to caregivers. These initiatives offer practical tools to manage stress, enhance communication, and manage overall mental health. By equipping caregivers with knowledge, we empower them to navigate the challenges with greater understanding and confidence.

Peer support networks represent another vital facet of caregiver well-being. Establishing communities where caregivers can share experiences, exchange coping strategies, and find solace in shared understanding is paramount. Breaking the isolation barrier can significantly alleviate the emotional burden on caregivers, creating a sense of belonging in a community that comprehends their unique struggles.

Yet, the responsibility does not rest solely on caregivers and their communities. Institutions and policymakers must step forward to enact supportive measures. By addressing systemic barriers, we acknowledge the societal responsibility to nurture the mental health of those who selflessly nurture others.

In nurturing the mental health of caregivers, we fortify the backbone of the recovery process, ensuring a more resilient, compassionate, and sustainable path forward.
Who Care for our Caregivers? Building the Evidence For Change
Authors: Bates Lauren
Published: April 2024

Unpaid caregivers are in distress. Almost two thirds (63%) of caregivers are at the breaking point – but feel they have no choice but to continue on (Spotlight Report: 2022). While caregivers find their role meaningful and know that they play a crucial role in sustaining our health, social and long-term care systems, they also feel invisible and unvalued, struggling with only ad hoc support. The Ontario Caregiver Coalition, a grassroots non-profit coalition of caregivers and the organizations that support them, is advocating for recognition and support for the family, friends and neighbours whose unpaid care is the hidden backbone of Ontario’s health system.
NAMI Family-to-Family Program Focuses on Family Caregiver Needs
Authors: Miller Elaine
Published: April 2024

National Alliance on Mental Illness (NAMI) Family-to-Family Program now being offered at Ontario Shores in virtual format, including how and where it was designed, its duration, the class topics, and how it helps family caregivers.  Participant testimonials are shared in the article as well as how to register for the course for those interested in taking it.
Comparative analysis of long-term results of surgical treatment of children with basal encephaloceles
Authors:   FSAI N. N. Burdenko National Medical Research Center of Neurosurgery of the Ministry of Health of Russia, Chernikova N. A. , Satanin L. A. ,   FSAI N. N. Burdenko National Medical Research Center of Neurosurgery of the Ministry of Health of Russia, Shelesko E. V. ,   FSAI N. N. Burdenko National Medical Research Center of Neurosurgery of the Ministry of Health of Russia, Evteev A. A. ,   Lomonosov Moscow State University, Strunina Yu. V. ,   FSAI N. N. Burdenko National Medical Research Center of Neurosurgery of the Ministry of Health of Russia, Sakharov A. V. ,   FSAI N. N. Burdenko National Medical Research Center of Neurosurgery of the Ministry of Health of Russia, Roginskiy V. V. ,   FSBI Central Research Institute of Dentistry and Maxillofacial Surgery of the Ministry of Health of Russia,
Published: April 2024

Basal encephaloceles (skull base hernias) are a rare pathology manifested by prolapse of altered membranes and brain tissue through a bone defect of the skull base. Endoscopic access is safer and is currently used as the method of choice in the treatment of this pathology. Available literature studies do not cover the quality of life of these patients at follow-up. There is a controversy regarding the impact of endoscopic access on the growth centers of the facial skeleton. Material and methods. A retrospective analysis of a series of 100 patients aged 0 to 18 years with basal encephaloceles who underwent surgical treatment at the N. N. Burdenko National Medical Research Center of Neurosurgery from 2005 to 2022 was carried out to determine the effectiveness and safety of the endoscopic method in the treatment of patients with basal encephaloceles and identify factors affecting the quality of life of these patients. Results and conclusions. Endoscopic endonasal access in the treatment of children with basal encephaloceles is effective and safe. Patients have a high quality of life (>85 points) at follow-up. After the operation, there is an improvement in nasal breathing and an increase in the degree of psychomotor development. Patients have a high quality of life (>85 points) at follow-up. A lower quality of life at follow-up was observed in children with delayed psychomotor development before surgery (OR=0.6; p=0.003). The follow-up study of the dynamics of craniometric parameters did not reliably show any disturbances in the growth of the bones of the facial skeleton in patients after endoscopic surgery.
Stroke-associated pneumonia: diagnosis, prevention, and treatment
Authors:   FSBSI Federal Research and Clinical Center of Intensive Care Medicine and Rehabilitology,, Cheboksarov D. V. , Ryzhova O. V. ,   FSBSI Federal Research and Clinical Center of Intensive Care Medicine and Rehabilitology,, Artyukov O. P. ,   FSAEI HE Peoples’ Friendship University of Russia named after Patrice Lumumba of the Ministry of Education and Science of the Russian Federation
Published: April 2024

Relevance. Stroke-associated pneumonia is often caused by aspiration, since the swallowing reflex is reduced or weakened in patients with an acute cerebrovascular accident. To protect the respiratory tract from aspiration, a protective intubation of the trachea is performed. However, this procedure does not provide complete protection against microaspiration. Comprehending the mechanisms and risk factors, as well as attempts to reduce them, contribute to the prevention of stroke-related pneumonia. Materials and methods. The search for Russian publications was carried out in the database on the RSCI website, and foreign publications were searched for in the PubMed and Google Scholar databases in the period from 2000 to 2022. When analyzing the PubMed database, the query «stroke pneumonia» found 6,033 links. We also studied works on the following key words: «acute stroke», «dysphagia», and «stroke-associated pneumonia». Publications describing the clinical picture, diagnosis, and treatment of stroke-associated pneumonia were analyzed. A total of 47 articles were examined. Conclusions. Stroke-associated pneumonia is a serious complication; research on this topic is limited, and the proposed methods of treatment are not definitive and in some cases are conservative. In addition, some of the prevention strategies mentioned in this article need further research to confirm.
Experience in treating hemifacial spasm combined with facial nerve neuropathy. A clinical case report
Authors:   FSAI N. N. Burdenko National Medical Research Center of Neurosurgery of the Ministry of Health of the Russian Federation, Moscow, Russia, Akulov M. A. , Shimanskiy V. N. ,   FSAI N. N. Burdenko National Medical Research Center of Neurosurgery of the Ministry of Health of the Russian Federation, Moscow, Russia, Poshataev V. K. ,   FSAI N. N. Burdenko National Medical Research Center of Neurosurgery of the Ministry of Health of the Russian Federation, Moscow, Russia, Orlova O. R. ,   FSAEI HE I. M Sechenov First Moscow State Medical University of the Ministry of Health of the Russian Federation (Sechenov University), Moscow, Russia, Zakharov V. O. ,   FSAI N. N. Burdenko National Medical Research Center of Neurosurgery of the Ministry of Health of the Russian Federation, Moscow, Russia
Published: April 2024

Hemifacial spasm (HFS) is a spontaneous paroxysmal contraction of the facial muscles caused by the presence of a neurovascular conflict between the root of the facial ner ve and the vessel of the base of the posterior cranial fossa. With prolonged duration, patients may develop facial nerve neuropathy. The aim of this article was to describe the treatment principles for patients with HFS in the presence of facial nerve neuropathy symptoms. The paper presents a clinical case of a female patient who had been experiencing HFS symptoms for a long time, accompanied by symptoms of facial nerve neuropathy (synkinetic movements, facial asymmetry, myokymia, and facial muscle contractions). Despite multiple courses of botulinum toxin therapy (with various preparations), the effectiveness of the treatment decreased. The patient underwent microvascular decompression, after which the HFS symptoms regressed, and the courses of botulinum toxin injections were continued to reduce the symptoms of facial nerve neuropathy. Conclusion: In cases of HFS with accompanying symptoms of facial nerve neuropathy (synkinetic movements, facial asymmetry, myokymia, and facial muscle contractions) of prolonged duration, it is necessary to eliminate the neurovascular conflict first and subsequently treat these symptoms using botulinum toxin type A.
Mathematical modeling of cochlear mechanics
Authors:   Pirogov Russian National Research Medical University, Ivankova A. E. , Trofimova P. P. ,   Pirogov Russian National Research Medical University, Utovka O. V. ,   Pirogov Russian National Research Medical University, Mirzaliev М. М. ,   Pirogov Russian National Research Medical University, Magomedov M. A. ,   Federal State Budgetary Educational Institution of Higher Education «Dagestan State Technical University», Makhachkala, Temirov A. T. ,   Federal State Budgetary Educational Institution of Higher Education «Dagestan State Technical University», Makhachkala
Published: April 2024

The cochlea plays a crucial role in sound perception. It acts as a frequency analyzer and amplifier of lowfrequency sounds. The mechanisms underlying these functions are not fully understood, as its anatomical position as well as its active nonlinear behavior can be altered by invasive observation. The article therefore focuses on improving our understanding of cochlear function by considering different approaches to modeling its mechanics, which is intended to aid in the interpretation of experimental observations. The methodological framework of the article is based on the following set of methods: analysis, synthesis, modeling, and systematization. In the framework of the ongoing research, mathematical modeling of cochlear mechanics is presented, in particular, the general formulation of the state space of the cochlea is outlined. Special attention is paid to the modeling of the auditory nerve synapse and nonlinear damping.
The effect of social media marketing on Instagram towards purchase intention of skincare products among Youth in Klang Valley
Authors: Tauhit Edrina Syamimi , Asmadi Farisha
Published: April 2024

People from different groups of ages use social media as one of the mediums to shop for skincare products especially among youth. There is a growth in product marketing that utilises social media especially on Instagram to get a higher engagement with potential customers in buying skincare products. However, some posts on Instagram that market skincare products are too good to be true resulting in Instagram users to contemplate on whether to purchase the product or just scroll through. This research will be based on the theory of reasoned action and employs a quantitative analysis where questionnaires will be distributed among youth live in Klang Valley. In this study, researchers look at the effects and the factors that contribute towards users’ purchase intention based on social media marketing. There is a positive correlation between social media marketing activities such as sponsored posts, brand pages, and skincare product reviews and the likelihood of consumers paying attention to these posts and making a purchase. The data collected is analysed by using SPSS in doing correlation and regression analysis. The findings indicate that Instagram usage increases the purchase intention among youth due to the enjoyment felt when using Instagram. This is because rewards, absorption and autonomy provide enjoyment towards youth and increase their purchase intention towards skincare products. Future research needs to be done to examine if competition to obtain popular skincare products has the same influence towards purchase intention among youth on Instagram.
Accepting Timor Leste as an ASEAN member: an act of compassion or a geopolitical necessity?
Authors: Azis Aswin Ariyanto , Safira Virda
Published: April 2024

Timor Leste has been accepted “in principle” as the 11th ASEAN country in 2022, after 11 years of waiting.  The 11-year delay is said to be due to skepticism from some Southeast Asian countries, which consider Timor-Leste an “uncertain situation”.  Many domestic issues, influenced by the international context, have added to this situation. These include concerns about the consolidation of democratic state institutions in Timor-Leste, as well as the prospects for its short-term economy and internal security. Existing solely on the decline of the Petroleum Fund, which is expected to disappear within a decade, the country risks falling into a budget abyss.  As the smallest economy in the entire Southeast Asia region, with the second lowest GDP per capita and high poverty and unemployment rates, Timor Leste has a long way to go to catch up with the remaining members of ASEAN.  Despite these economic shortcomings, ASEAN still decided to accept Timor Leste as a new member.  This article aims to explain Timor-Leste's credibility in meeting the political, economic and socio-cultural security criteria of the ASEAN pillars. It tries to explain why ASEAN accepted Timor-Leste. Using qualitative methods, the article shows that ASEAN member states have a real incentive to help Timor catch up with other members to avoid its economic collapse.  However, the growing geopolitical rivalry between China and the US in the region is perhaps the best explanation for ASEAN's eventual desire to accept Timor Leste's membership application.