31 research outputs found

    Formation and Characterization of Crystalline Hydroxyapatite Coating with the (002) Texture

    Get PDF
    This study reports the effect of titanium (Ti) microstructure on the mechanical properties and surface wettability of thin (<800 nm) hydroxyapatite (HA) coating deposited via radio-frequency (RF) magnetron sputtering. It was revealed that the sand-blasting (SB) and acid etching (AE) of Ti prior deposition led to a wide range of surface roughness in nano/micro scale. After nanostructured HA coating deposition such physico-mechanical characteristics as nanohardness H, Young's modulus E, H/E ratio and H[3]/E[2] were significantly improved. Moreover, HA coatings exhibited improved wear resistance, lower friction coefficient and ability of the coating to wetting

    The role of retraining technologies of personnel in ensuring financial stability of transport and industrial companies

    Get PDF
    The industry-based companies with state participation operating in the Russian Federation are significant producers of economic growth and core economic entities identifying the Russian labor market growth. In terms of risky business environment, the mechanism for implementing personnel development strategy at transport and industrial companies with state participation in the capital assets, which are based on an innovative personnel training and retraining system, determines the vector of ensuring their financial stability. Considering the latter, the risk management of transport and industrial companies’ personnel development is directly related to the strategy for the intangible assets formation. It also ensures institutionalization of promising systems of human capital management.peer-reviewe

    Glutamate Concentration in the Serum of Patients with Schizophrenia

    Get PDF
    Glutamate is the major neurotransmitter with multiple functions in the central nervous system. Glutamate-mediated excitotoxicity is involved in the pathophysiological processes in schizophrenia. The purpose of this study was to determine the concentration of glutamate in the serum of patients with paranoid schizophrenia compared with healthy individuals, and depending on the duration of the schizophrenic process and leading clinical symptoms. We investigated the level of glutamate in the serum of 158 patients with paranoid schizophrenia and 94 healthy persons. Higher concentrations of glutamate in schizophrenic patients compared with healthy persons have been found. The maximum concentrations of glutamate were detected in patients with disease duration of more than ten years. Glutamate level in the serum does not depend on the prevailing negative or positive clinical symptoms. The increased concentration of glutamate can hypothetically contribute to dopaminergic and glutamatergic imbalance, leading to the development of psychotic symptoms and cognitive dysfunction

    Numerical simulation of the fractures of anisotropic materials characterized by the high degree of anisotropy of elongation at break

    Get PDF
    The failure criteria of anisotropic materials, the criteria being expressed via deformations, are rarely applied in practice, and are usually used for low-ductility materials. Another situation involves the simulation of failures in materials with the high anisotropy of mechanical properties and that suffer elastic-brittle fracture. For such materials the failure criteria are formulated using ultimate strains and strain tensor invariants. For simulating the fractures of materials that are characterized by the anisotropy of strength properties, the failure criteria are applied with the critical values of stresses and strains, as well as their intensities. Using the value of cumulative plastic strain as a failure criterion does reflect the anisotropy of elastic and plastic properties of a material, but it does not reflect that of the strength properties. The application of this method allows accounting the total plastic strain induced by tension and compression in the conditions of the wave strain of targets during their impact loading

    Kinetic non-reversibility of the cracking reactions and its accounting during mathematical modeling of industrial process

    Get PDF
    The paper presents the approach to the catalytic cracking modeling with consideration of the reactions' reversibility/non-reversibility depending on the current concentrations and the cracking temperature. The thermodynamic analysis of the reactions using the quantum-chemical methods allows formulating a hydrocarbons conversion scheme at the thermal equilibrium temperature between the feedstock and the catalyst. The magnitude of the current chemical attraction of reactions is a criterion of thermodynamic non-reversibility of reactions, which is determined at each stage of the calculation. It has been shown that the change in the concentrations of conversion participants and cracking temperature have a significant effect on the catalytic cracking reactions. Thus, the cyclization reactions are non-reversible up to 512.9 °C (A[rij]=6.46 kJ/mol) during the processing of feedstock with saturated hydrocarbons to aromatics ratio is 2.1 and with further temperature increasing the contribution of reverse reactions rises. Also with increasing the saturated hydrocarbons to aromatics ratio from 2.1 to 3.2 in the feedstock, the equilibrium of the reaction shifts to low temperatures from 512.9 to 508.9 °C (A[rij]=6.497 kJ/mol). It is connected with the fact that intensification of the exotermic reactions (alkylation, condensation, coke formation) under certain conditions is possible. It is an important factor in terms of catalyst deactivation and has an effect on the desired product yield

    Genetics of psycho-emotional well-being: genome-wide association study and polygenic risk score analysis

    Get PDF
    BackgroundPsycho-emotional well-being is essential for living a life of satisfaction and fulfillment. However, depression and anxiety have become the leading mental health issues worldwide, according to the World Health Organization. Both disorders have been linked to stress and other psychological factors. Their genetic basis remains understudied.MethodsIn 2020–2021, the psycho-emotional well-being of 30,063 Russians with no known psychiatric history was assessed using the Hospital Anxiety and Depression Scale (HADS) for general mental health and the HADS subscale A (anxiety) for anxiety. Following the original instructions, an anxiety score of ≥11 points was used as the anxiety threshold. A genome-wide association study was performed to find associations between anxiety and HADS/HADS-A scores using linear and logistic regressions based on HADS/HADS-A scores as binary and continuous variables, respectively. In addition, the links between anxiety, sociodemographic factors (such as age, sex, and employment), lifestyle (such as physical activity, sleep duration, and smoking), and markers of caffeine and alcohol metabolism were analyzed. To assess the risk of anxiety, polygenic risk score modeling was carried out using open-access software and principal component analysis (PCA) to simplify the calculations (ROC AUC = 89.4 ± 2.2% on the test set).ResultsThere was a strong positive association between HADS/HADS-A scores and sociodemographic factors and lifestyle. New single-nucleotide polymorphisms (SNPs) with genome-wide significance were discovered, which had not been associated with anxiety or other stress-related conditions but were located in genes previously associated with bipolar disorder, schizophrenia, or emotional instability. The CACNA1C variant rs1205787230 was associated with clinical anxiety (a HADS-A score of ≥11 points). There was an association between anxiety levels (HADS-A scores) and genes involved in the activity of excitatory neurotransmitters: PTPRN2 (rs3857647), DLGAP4 (rs8114927), and STK24 (rs9517326).ConclusionOur results suggest that calcium channels and monoamine neurotransmitters, as well as SNPs in genes directly or indirectly affecting neurogenesis and synaptic functions, may be involved in the development of increased anxiety. The role of some non-genetic factors and the clinical significance of physiological markers such as lifestyle were also demonstrated

    Differential expression of alternatively spliced transcripts related to energy metabolism in colorectal cancer

    Full text link

    Update and guidance on management of myopia. European Society of Ophthalmology in cooperation with International Myopia Institute

    Get PDF
    The prevalence of myopia is increasing extensively worldwide. The number of people with myopia in 2020 is predicted to be 2.6 billion globally, which is expected to rise up to 4.9 billion by 2050, unless preventive actions and interventions are taken. The number of individuals with high myopia is also increasing substantially and pathological myopia is predicted to become the most common cause of irreversible vision impairment and blindness worldwide and also in Europe. These prevalence estimates indicate the importance of reducing the burden of myopia by means of myopia control interventions to prevent myopia onset and to slow down myopia progression. Due to the urgency of the situation, the European Society of Ophthalmology decided to publish this update of the current information and guidance on management of myopia. The pathogenesis and genetics of myopia are also summarized and epidemiology, risk factors, preventive and treatment options are discussed in details
    corecore