Репозиторий Университета

© 2020 Elsevier B.V. For thermoelements operating on the Peltier and Seebeck effects, including multisection ones used at temperatures up to 900 K, the physicochemical principles of creating effective thin-film multilayer contact systems obtained by magnetron ion-plasma sputtering have been developed. The formation of contact systems was carried out on thermoelectric materials based on: Bi2Te3; Sb2Te3; PbTe; GeTe with the increased thermoelectric figure of merit. A structure of contact systems consisting of contact layers providing ohmic contact, adhesion, barrier and interconnection properties of contact systems is proposed and justified. The selection criteria for materials of contact layers are substantiated. For multisection thermoelements operating on the Seebeck effect at temperatures above 500 K, the necessity of introducing diffusion-barrier layers into the structure of contact systems providing reliability and invariability of the properties of contact systems is substantiated. Based on the physicochemical analysis, the thermodynamic and kinetic factors of the stability and degradation of diffusion-barrier layers are determined. The influence of methods for preparing the surface of thermoelectric materials on the adhesion, contact resistance, and thermal stability of contact systems is established. Using Auger electron spectroscopy, the analysis of the causes of thermal stability and degradation of contact systems was carried out. The deposition modes were determined. The effective contact systems were obtained and investigated. The respective systems are based on: Ni; Mo/Ni and Ni/(Ta–W–N)/Ni having the adhesive strength of more than 12 MPa; the contact resistance not exceeding 10−9 Ω m2 and thermal stability at temperatures up to 900 K.

© 2020 Elsevier B.V. For thermoelements operating on the Peltier and Seebeck effects, including multisection ones used at temperatures up to 900 K, the physicochemical principles of creating effective thin-film multilayer contact systems obtained by magnetron ion-plasma sputtering have been developed. The formation of contact systems was carried out on thermoelectric materials based on: Bi2Te3; Sb2Te3; PbTe; GeTe with the increased thermoelectric figure of merit. A structure of contact systems consisting of contact layers providing ohmic contact, adhesion, barrier and interconnection properties of contact systems is proposed and justified. The selection criteria for materials of contact layers are substantiated. For multisection thermoelements operating on the Seebeck effect at temperatures above 500 K, the necessity of introducing diffusion-barrier layers into the structure of contact systems providing reliability and invariability of the properties of contact systems is substantiated. Based on the physicochemical analysis, the thermodynamic and kinetic factors of the stability and degradation of diffusion-barrier layers are determined. The influence of methods for preparing the surface of thermoelectric materials on the adhesion, contact resistance, and thermal stability of contact systems is established. Using Auger electron spectroscopy, the analysis of the causes of thermal stability and degradation of contact systems was carried out. The deposition modes were determined. The effective contact systems were obtained and investigated. The respective systems are based on: Ni; Mo/Ni and Ni/(Ta–W–N)/Ni having the adhesive strength of more than 12 MPa; the contact resistance not exceeding 10−9 Ω m2 and thermal stability at temperatures up to 900 K.

© 2020 The Authors Genome-wide screening approaches identified the cell adhesion molecule Cadherin-13 (CDH13) as a risk factor for neurodevelopmental disorders, nevertheless the contribution of CDH13 to the disease mechanism remains obscure. CDH13 is involved in neurite outgrowth and axon guidance during early brain development and we previously provided evidence that constitutive CDH13 deficiency influences the formation of the raphe serotonin (5-HT) system by modifying neuron-radial glia interaction. Here, we dissect the specific impact of CDH13 on 5-HT system development and function using a 5-HT neuron-specific Cdh13 knockout mouse model (conditional Cdh13 knockout, Cdh13 cKO). Our results show that exclusive inactivation of CDH13 in 5-HT neurons selectively increases 5-HT neuron density in the embryonic dorsal raphe, with persistence into adulthood, and serotonergic innervation of the developing prefrontal cortex. At the behavioral level, adult Cdh13 cKO mice display delayed acquisition of several learning tasks and a subtle impulsive-like phenotype, with decreased latency in a sociability paradigm alongside with deficits in visuospatial memory. Anxiety-related traits were not observed in Cdh13 cKO mice. Our findings further support the critical role of CDH13 in the development of dorsal raphe 5-HT circuitries, a mechanism that may underlie specific clinical features observed in neurodevelopmental disorders.

© 2020 The Authors Genome-wide screening approaches identified the cell adhesion molecule Cadherin-13 (CDH13) as a risk factor for neurodevelopmental disorders, nevertheless the contribution of CDH13 to the disease mechanism remains obscure. CDH13 is involved in neurite outgrowth and axon guidance during early brain development and we previously provided evidence that constitutive CDH13 deficiency influences the formation of the raphe serotonin (5-HT) system by modifying neuron-radial glia interaction. Here, we dissect the specific impact of CDH13 on 5-HT system development and function using a 5-HT neuron-specific Cdh13 knockout mouse model (conditional Cdh13 knockout, Cdh13 cKO). Our results show that exclusive inactivation of CDH13 in 5-HT neurons selectively increases 5-HT neuron density in the embryonic dorsal raphe, with persistence into adulthood, and serotonergic innervation of the developing prefrontal cortex. At the behavioral level, adult Cdh13 cKO mice display delayed acquisition of several learning tasks and a subtle impulsive-like phenotype, with decreased latency in a sociability paradigm alongside with deficits in visuospatial memory. Anxiety-related traits were not observed in Cdh13 cKO mice. Our findings further support the critical role of CDH13 in the development of dorsal raphe 5-HT circuitries, a mechanism that may underlie specific clinical features observed in neurodevelopmental disorders.

© 2020 The Authors Genome-wide screening approaches identified the cell adhesion molecule Cadherin-13 (CDH13) as a risk factor for neurodevelopmental disorders, nevertheless the contribution of CDH13 to the disease mechanism remains obscure. CDH13 is involved in neurite outgrowth and axon guidance during early brain development and we previously provided evidence that constitutive CDH13 deficiency influences the formation of the raphe serotonin (5-HT) system by modifying neuron-radial glia interaction. Here, we dissect the specific impact of CDH13 on 5-HT system development and function using a 5-HT neuron-specific Cdh13 knockout mouse model (conditional Cdh13 knockout, Cdh13 cKO). Our results show that exclusive inactivation of CDH13 in 5-HT neurons selectively increases 5-HT neuron density in the embryonic dorsal raphe, with persistence into adulthood, and serotonergic innervation of the developing prefrontal cortex. At the behavioral level, adult Cdh13 cKO mice display delayed acquisition of several learning tasks and a subtle impulsive-like phenotype, with decreased latency in a sociability paradigm alongside with deficits in visuospatial memory. Anxiety-related traits were not observed in Cdh13 cKO mice. Our findings further support the critical role of CDH13 in the development of dorsal raphe 5-HT circuitries, a mechanism that may underlie specific clinical features observed in neurodevelopmental disorders.

© 2019 Elsevier Ltd Adhesion G protein-coupled receptor L3 (ADGRL3, LPHN3) has putative roles in neuronal migration and synapse function. Various polymorphisms in ADGRL3 have been linked with an increased risk of attention deficit/hyperactivity disorder (ADHD). In this study, we examined the characteristics of Adgrl3-deficient mice in multiple behavioural domains related to ADHD: locomotive activity, impulsivity, gait, visuospatial and recognition memory, sociability, anxiety-like behaviour and aggression. Additionally, we investigated the effect of Adgrl3-depletion at the transcriptomic level by RNA-sequencing three ADHD-relevant brain regions: prefrontal cortex (PFC), hippocampus and striatum. Adgrl3 −/− mice show increased locomotive activity across all tests and subtle gait abnormalities. These mice also show impairments across spatial memory and learning domains, alongside increased levels of impulsivity and sociability with decreased aggression. However, these alterations were absent in Adgrl3 +/− mice. Across all brain regions tested, the numbers of genes found to exhibit differential expression was relatively small, indicating a specific pathway of action, rather than a broad neurobiological perturbation. Gene-set analysis of differential expression in the PFC detected a number of ADHD-relevant pathways including dopaminergic synapses as well as cocaine and amphetamine addiction. The Slc6a3 gene coding for the dopamine transporter was the most dysregulated gene in the PFC. Unexpectedly, several neurohormone/peptides which are typically only expressed in the hypothamalus were found to be dysregulated in the striatum. Our study further validates Adgrl3 constitutive knockout mice as an experimental model of ADHD while providing neuroanatomical targets for future studies involving ADGRL3 modified models. This article is part of the Special Issue entitled ‘Current status of the neurobiology of aggression and impulsivity’.

© 2018 by the authors. Objectives: Resin-modified glass ionomer cements (RMGIC) are considered excellent restorative materials with unique therapeutic and anti-cariogenic activity. However, concerns exist regarding the use of polyacrylic acid as a dentine conditioner as it may influence the bonding performance of RMGIC. The aim of this study was to evaluate the effect of different protocols for cycling mechanical stress on the bond durability and interfacial ultramorphology of a modern RMGIC applied to dentine pre-treated with/without polyacrylic acid conditioner (PAA). Methods: The RMGIC was applied onto human dentine specimens prepared with silicon-carbide (SiC) abrasive paper with or without the use of a PAA conditioner. The specimens were immersed in deionised water for 24 h then divided in 3 groups. The first group was cut into matchsticks (crosssectional area of 0.9 mm2) and tested immediately for microtensile bond strength (MTBS). The second was first subjected to load cycling (250,000 cycles; 3 Hz; 70 N) and then cut into matchsticks and tested for MTBS. The third group was subjected to load cycling (250,000 cycles; 3 Hz; 70 N), cut into matchsticks, and then immersed for 8 months storage in artificial saliva (AS); these were finally tested for MTBS. The results were analysed statistically using two-way ANOVA and the Student- Newman-Keuls test (α = 0.05). Fractographic analysis was performed using FE-SEM, while further RMCGIC-bonded dentine specimens were aged as previously described and used for interfacial ultramorphology characterisation (dye nanoleakage) using confocal microscopy. Results: The RMGIC applied onto dentine that received no pre-treatment (10% PAA gel) showed no significant reduction in MTBS after load cycling followed by 8 months of storage in AS (p > 0.05). The RMGIC- dentine interface created in PAA-conditioned SiC-abraded dentine specimens showed no sign of degradation, but with porosities within the bonding interface both after load cycling and after 8 months of storage in AS. Conversely, the RMGIC-dentine interface of the specimens with no PAA pre-treatment showed no sign of porosity within the interface after any of the aging protocols, although some bonded-dentine interfaces presented cohesive cracks within the cement after prolonged AS storage. However, the specimens of this group showed no significant reduction in bond strength (p < 0.05) after 8 months of storage in AS or load cycling (p > 0.05). After prolonged AS storage, the bond strength value attained in RMGIC-dentine specimens created in PAA pretreated dentine were significantly higher than those observed in the specimens created with no PAA pre-treatment in dentine. Conclusions: PAA conditioning of dentine prior to application of RMGIC induces no substantial effect on the bond strength after short-term storage, but its use may increase the risk of collagen degradation at the bonding interface after prolonged aging. Modern RMGIC applied without PAA dentine pre-treatment may have greater therapeutic synergy with saliva during cycle occlusal load, thereby enhancing the remineralisation and protection of the bonding interface.

© Copyright 2018 Inderscience Enterprises Ltd. This paper is concerned with the studies of a natural nanomaterial which is bacterial cellulose synthesised by Gluconacetobacter hansenii producer strain. It covers different fields of bacterial cellulose use, including medicine. The research has proved that bacterial cellulose matrices with immobilised cells have high potential as immobilisers of cells, including making probiotics of prolonged action. The matrices consisted of bacterial cellulose films were prepared by static cultivation of G. hansenii GH-1/2008 strain in the liquid medium. We have developed methods of washing out end toxins and producer cells of the films in the solutions of sodium bicarbonate, sodium dodecyl sulphate, and sodium hydroxide. The LAL-test has revealed that washing the films with sodium dodecyl sulphate is more efficient. By means of electron scanning and atomic force microscopy (AFM), we have determined that bacterial cellulose matrices have a layered structure, smooth surface, and adhesion of E. coli test strain cells. The adhesive capacity, the energy of adhesion and contact angle is higher for 50 um thick films than for 20 um thick ones. The bacterial cellulose matrices obtained by the biosynthesis of G. hansenii strain can be recommended for the immobilisation of different producer cells.