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Surface modification of polylactide films was performed using a dielectric barrier discharge (DBD) with the aim of increasing proliferative activity of human fibroblasts on these films. It has been shown that during the plasma treatment of the polylactide film, nonlinear processes occur depending on the processing time. The effect of the dielectric barrier discharge on the modification of polylactide films was evaluated using IR spectroscopy, AFM, XPS, TSDC, and the wetting angle of the surface. The optimal processing time in DBD of polylactide films is 3 min for this installation, the proliferative activity increases by 10% compared to the original film. This treatment time provides an increased concentration of oxygen-containing groups, optimal relief, and free surface energy of 55 mJ/[m.sup.2] on the surface. Highlights * The biocompatibility of the polylactide film was improved by 10% used DBD. * The optimal processing time of PLA films in DBD is 3 min. * The functionalization of the polylactide surface occurs non-linearly, KEYWORDS cell cultivation, dielectric barrier discharge, plasma, polylactide, surface modification, 1 | INTRODUCTION Poly (lactic acid) or polylactide (PLA) is the most widely researched and used biodegradable and renewable aliphatic polyester. PLA can be used to replace conventional petrochemical-based polymers [...]

Background: Population studies are essential for gathering critical disease prevalence data. Automated pathogenicity assessment tools enhance the capacity to interpret and annotate large amounts of genetic data. In this study, we assessed the prevalence of cancer-associated germline variants in Russia using a semiautomated variant interpretation algorithm. Methods: We examined 74,996 Russian adults (Group 1) and 2,872 long-living individuals aged = 90 years (Group 2) for variants in 28 ACMG-recommended cancer-associated genes in three steps: InterVar annotation; ClinVar interpretation; and a manual review of the prioritized variants based on the available data. Using the data on the place of birth and the region of residence, we determined the geographical distribution of the detected variants and tracked the migration dynamics of their carriers. Results: We report 175 novel del-VUSs. We detected 232 pathogenic variants, 46 likely pathogenic variants, and 216 del-VUSs in Group 1 and 19 pathogenic variants, 2 likely pathogenic variants, and 16 del-VUSs in Group 2. For each detected variant, we provide a description of its functional significance and geographical distribution. Conclusion: The present study offers extensive genetic data on the Russian population, critical for future genetic research and improved primary cancer prevention and genetic screening strategies. The proposed hybrid assessment algorithm streamlines variant prioritization and pathogenicity assessment and offers a reliable and verifiable way of identifying variants of uncertain significance that need to be manually reviewed. [ABSTRACT FROM AUTHOR]

The relevance of the researched problem is caused by the society requirement to form and implement educational and creative potential of a student as a conductor of changes that set a high level of motivational behavior. The aim of this article is to develop a structural model of motivational behavior of students that allow carrying out modeling of specific characteristics and their practical application. The leading approach to the research of this problem is the provision of the theory of self-determination on basic needs that allow considering basics of intrinsic motivation. The results of the research are: the structural model of motivational behavior is considered in the article, the questions are selected and the questionnaire on educational motivation is developed for the poll of students' groups "Economy and Management". The development and approbation of multi-profile software programs are "Students' Questionnaire" to implement on-line poll or interviews with students on academic motivation. The results of the research can be useful for specialized structural divisions of the university, teachers, and also for the students in case of further research of the issues of academic motivation and individual educational paths.

This work is dedicated to the development and investigation of the properties of low‐dielectric‐constant nonwoven materials obtained by electrospinning from a polyimide‐based polymer, PMDA‐ODA, which is composed of pyromellitic dianhydride (PMDA) and 4,4′‐oxydianiline (ODA). The influence of the molar mass of PMDA‐ODA on the structural, mechanical, and dielectric properties of the resulting samples has been investigated. The molar mass of the polyimide has been determined through light scattering and viscosity measurements of polyamic acid solutions. As the molar mass of PMDA‐ODA increases from 13.400 to 49.300 g/mol, the glass transition temperature of the produced nonwoven samples increases, and their tensile mechanical properties are improved. The dielectric constant of PMDA‐ODA nonwoven polyimide materials varies from 1.55 to 1.91 at a temperature of 30°C in a frequency range from 1 Hz to 1 MHz, depending on the molar mass of the polymer used. [ABSTRACT FROM AUTHOR]

This paper provides a study of two bone substitutes: a hybrid porous polymer and an osteoplastic matrix based on a bovine-derived xenograft. Both materials are porous, but their pore characteristics are different. The osteoplastic matrix has pores of 300–600 µm and the hybrid polymer has smaller pores, generally of 6–20 µm, but with some pores up to 100 µm across. SEM data confirmed the porometry results and demonstrated the different structures of the materials. Therefore, both materials were characterized by an interconnected porous structure and provided conditions for the adhesion and vital activity of human ASCs in vitro. In an experimental model of rabbit shin bone defect, it was shown that, during the 6-month observation period, neither of the materials caused negative reactions in the experimental animals. By the end of the observation period, restoration of the defects in animals in both groups was completed, and elements of both materials were preserved in the defect areas. Data from morphological examinations and CT data demonstrated that the rate of rabbit bone tissue regeneration with the hybrid polymer was comparable to that with the osteoplastic matrix. Therefore, the hybrid polymer has good potential for use in further research and improvement in biomedical applications. [ABSTRACT FROM AUTHOR]

In the example of a rat model with chronic hepatoencephalopathy (HE), changes in the organ morphology of rats affect the balance of metabolites of the tricarboxylic acid (TCA) cycle and metabolites of the glutamine–glutamate (Gln-Glu) cycle, namely α-ketoglutarate (αKG) and α-ketoglutaramate (αKGM), as well as the enzymes associated with them, ω-amidase (ωA) and glutamine transaminase (GTK). This model of rats was obtained as a result of 2–22 weeks of consumption by animals of hepatotoxin thioacetamide (TAA) added to drinking water at a concentration of 0.4 g/L. The control (n = 26) and TAA-induced (n = 55) groups of rats consisted of 11 cohorts each. The control cohorts consisted of 2–4 rats, and the TAA-induced cohorts consisted of 4–7 individuals. Every two weeks, samples of blood plasma, liver, kidney, and brain tissues were taken from the next cohort of rats (a total of 320 samples). By the end of the experiment, irreversible morphological changes were observed in the organs of rats: the weight of the animals was reduced up to ~45%, the weight of the kidneys up to 5%, the brain up to ~20%, and the weight of the liver increased up to ~20%. The analysis revealed: (i) a decrease in the activity of ωA and GTK in the tissues of the brain, kidneys, and liver of rats with chronic HE (by ~3, 40, and 65% and ~10, 60, and 70%, respectively); and (ii) the appearance of a significant imbalance in the content of metabolites of the Gln-Glu cycle, αKG, and αKGM. It is indicative that a ~1.5–12-fold increase in the level of αKG in the blood plasma and tissues of the organs of rats with chronic HE was accompanied by a synchronous, ~1.2–2.5-fold decrease in the level of αKGM. The data obtained indicate an essential involvement of the Gln-Glu cycle in the regulation of energy metabolism in rats under conditions of chronic HE. Attention is focused on the significance of the αKG/αKGM ratio, which can act as a potential marker for diagnosing the degree of HE development. [ABSTRACT FROM AUTHOR]

Background: As the field of probiotic research continues to expand, new beneficial strains are being discovered. The Christensenellaceae family and its newly described member, Christensenella minuta, have been shown to offer great health benefits. We aimed to extensively review the existing literature on these microorganisms to highlight the advantages of their use as probiotics and address some of the most challenging aspects of their commercial production and potential solutions. Methods: We applied a simple search algorithm using the key words "Christensenellaceae" and "Christensenella minuta" to find all articles reporting the biotherapeutic effects of these microorganisms. Only articles reporting evidence-based results were reviewed. Results: The review showed that Christensenella minuta has demonstrated numerous beneficial properties and a wider range of uses than previously thought. Moreover, it has been shown to be oxygen-tolerant, which is an immense advantage in the manufacturing and production of Christensenella minuta-based biotherapeutics. The results suggest that Christensenellaceae and Christensenella munita specifically can play a crucial role in maintaining a healthy gut microbiome. Furthermore, Christensenellaceae have been associated with weight management. Preliminary studies suggest that this probiotic strain could have a positive impact on metabolic disorders like diabetes and obesity, as well as inflammatory bowel disease. Conclusion: Christensenellaceae and Christensenella munita specifically offer immense health benefits and could be used in the management and therapy of a wide range of health conditions. In addition to the impressive biotherapeutic effect, Christensenella munita is oxygen-tolerant, which facilitates commercial production and storage. [ABSTRACT FROM AUTHOR]

The article describes modern methods for producing one-, two-, and three-dimensional composite matrices for tissue engineering based on resorbable and non-resorbable polymers. Coagulation method for producing composite fibers based on chitosan and chitin nanofibrils, electrospinning method for composite nanofibers, lyophilization of chitosan solutions and their mixtures with nanoparticles to obtain three-dimensional porous matrices with increased stability of mechanical characteristics in aqueous media. The results of the study of the adhesion and kinetics of proliferation of stem and somatic cells of humans and animals on the developed matrices are presented. In vivo experiments have shown that materials in the form of fibers, films, tubular samples, and sponges can be used as implants for blood vessels, effective wound dressings. The article contains the results of the study of the kinetics of resorption of the studied materials in a living organism.

Heat resistant thermoplastic matrices offer potential advantages over thermoset polymers and represent a promising alternative in advanced composite applications. In the present work, the properties of carbon fiber reinforced plastics (CFRPs) based on the developed semicrystalline polyimide R‐BAPB were studied and compared with those of highly heat‐resistant thermoplastic polymers such as amorphous polyetherimide Ultem‐1000 and semicrystalline polyetherketone PEEK. To obtain CFRP, an approach was used basing on the uniform distribution of polymer powders on continuous carbon fibers by electrostatic spraying followed by their impregnation in heated calenders and hot pressing. The thermal and thermomechanical properties of CFRPs based on mentioned above polymers were studied. The effect of temperature on the mechanical behavior of CFRPs, including flexural properties and interlaminar fracture toughness G1C, was investigated as well. CFRPs based on PEEK and R‐BAPB are found to have the highest thermal stability and heat resistance. The maximum flexural strength, which practically does not change in a wide temperature range from −50 to 180°C, is observed for CFRP based on R‐BAPB polyimide. Among the investigated CFRPs, the highest value of interlaminar fracture toughness is shown by CFRPs based on semicrystalline R‐BAPB. [ABSTRACT FROM AUTHOR]

Porous polymer monoliths with thicknesses of 2 and 4 mm were obtained via polymerization of ethylene glycol dimethacrylate (EGDMA) under the influence visible-light irradiation in the presence of a 70 wt% 1-butanol porogenic agent and o-quinone photoinitiators. The o-quinones used were: 3,5-di-tret-butyl-benzoquinone-1,2 (35Q), 3,6-di-tret-butyl-benzoquinone-1,2 (36Q), camphorquinone (CQ), and 9,10-phenanthrenequinone (PQ). Porous monoliths were also synthesized from the same mixture but using 2,2′-azo-bis(iso-butyronitrile) (AIBN) at 100 °C instead o-quinones. According to the results of scanning electron microscopy, all the resulting samples were conglomerates of spherical, polymeric particles with pores between them. Use of mercury porometry showed that the interconnected pore systems of all the polymers were open. The average pore size, Dmod, in such polymers strongly depended on both the nature of the initiator and the method of initiation of polymerization. For polymers obtained in the presence of AIBN, the Dmod value was as low as 0.8 μm. For polymers obtained via photoinitiation in the presence of 36Q, 35Q, CQ, and PQ, the Dmod values were significantly greater, i.e., 9.9, 6.4, 3.6, and 3.7 μm, respectively. The compressive strength and Young's modulus of the porous monoliths increased symbatically in the series PQ < CQ < 36Q < 35Q < AIBN with decreasing proportions of large pores (over 12 μm) in their polymer structures. The photopolymerization rate of the EGDMA and 1-butanol, 30:70 wt% mixture was maximal for PQ and minimal for 35Q. All polymers tested were non-cytotoxic. Based on the data from MTT testing, it can be noted that the polymers obtained via photoinitiation were characterized by their positive effect on the proliferative activity of human dermal fibroblasts. This makes them promising osteoplastic materials for clinical trials. [ABSTRACT FROM AUTHOR]