28 research outputs found

    Comparative characteristic of Bi- and La- doped (Ca/Sr)MoO4 -based materials with a defect scheelite-type structure

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    CaMoO4- and SrMoO4-based scheelite-type phases are noteworthy functional materials, whose properties strongly correlate with their structure. This work is devoted to La- or Bi-doped scheelite-type molybdates. The purpose of the present study is to quantify the effect of isolated electron pairs of bismuth on the distortion of the structure and related properties. Conventional solid-state technology was used for the synthesis of (Ca/Sr)1–3xLa2xФxMoO4 and Sr1–3xBi2xФxMoO4, (0.025≤ x ≤ 0.275). The structure was investigated by X-ray powder diffraction and Raman spectroscopy. Rates of structure distortion were characterised by the analysis of the autocorrelation function (AAF) of Raman spectra. Energy gaps were calculated by the Kubelka-Munk method. The conductivity was studied with a.c. impedance spectroscopy. For (Ca/Sr)1−3x(Bi/La)2xФxMoO4 series 0.025 ≤ x ≤ 0.15 compositions show a basic defect scheelite structure, while 0.15 x ≤ 0.225 compositions of Bi-doped samples exhibit tetragonal supercells. The chemical compression of unit cell is more evident in the case of Bi-doping, indicating the preferred orientation of the isolated electron pairs. The distortion of MoO4 polyhedra showed by AAF was more significant for Sr1−3xBi2xФxMoO4 than for Sr1−3xLa2xФxMoO4, the Δcorr parameters for Bi-doped compositions were almost double in comparison with La-doped one in the range of 50–600 cm–1 of the Raman shift. The «critical» x = 0.15 point was also clearly indicated by Δcorr parameter. The AAF of the Raman spectra of solid oxides was shown to be a good tool for prediction of properties and points of phase transitions in solid oxides

    Pilot study of transcranial photobiomodulation of lymphatic clearance of beta-amyloid from the mouse brain: breakthrough strategies for non-pharmacologic therapy of Alzheimer's disease

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    In this pilot study, we analyzed effects of transcranial photobiomodulation (tPBM, 1267 nm, 32 J/cm2) on clearance of beta-amyloid (Aβ) from the mouse brain. The immunohistochemical and confocal data clearly demonstrate the significant reduction of deposition of Aβ plaques in mice after tPBM vs. untreated animals. The behavior tests showed that tPBM improved the cognitive, memory and neurological status of mice with Alzheimer’s disease (AD). Using of our original method based on optical coherence tomography (OCT) analysis of clearance of gold nanorods (GNRs) from the brain, we proposed possible mechanism underlying tPBM-stimulating effects on clearance of Aβ via the lymphatic system of the brain and the neck. These results open breakthrough strategies for a non-pharmacological therapy of Alzheimer’s disease and clearly demonstrate that tPBM might be a promising therapeutic target for preventing or delaying Alzheimer’s disease

    A clinical case of post-COVID-19 myoendocarditis and arrhythmic syndrome at the outpatient stage

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    Background: Infection with the SARS-CoV-2 virus entails the development of complications which affect the prognosis of the underlying disease. More than 40% of COVID-19 complications represent diseases of the cardiovascular system, most of which are the rhythm and conduction disturbances. In order to avoid these complications, it is necessary to detect cases of infection in a timely manner at the outpatient stage. Clinical case description: A 40-year-old patient came to the clinic with complaints of interruptions in the heart rhythm that appeared after the coronavirus infection. The laboratory examination (CBC) revealed signs of systemic inflammation (leukocytosis 12.6×109 U/l; erythrocyte sedimentation rate 18 mm/h, C-reactive protein 18 mg/l); the instrumental examination of the heart revealed the rhythm disturbances in the form of frequent ventricular ectopic activity and weakness of the SA node. The patient received propafenone (150 mg, 3 times a day) as a therapy with a positive effect. Against the background of improvement in the patient’s condition and despite the history of myocarditis and a positive result of enzyme immunoassay for antibodies to SARS-CoV-2 (IgG, 10 BAU/ml), the patient was prescribed immunization with the CoviVac vaccine. After the immunization, the condition worsening was observed in the form of an increase in the rhythm disturbances, which required an inpatient treatment. A clinical diagnosis of recurrent ventricular arrhythmia — ventricular extrasystole was established, and the therapy was corrected. The outcome was favorable. Conclusion: Myocarditis is one of the most common complications of SARS-CoV-2 and should be kept in mind at all stages of medical care. This clinical case demonstrates the importance of the correct diagnosis and treatment of post-COVID myocarditis, as well as the need to assess contraindications for SARS-CoV-2 vaccination in patients with cardiac complications

    Outcomes of the multicenter monitoring of the causative agent of invasive listeriosis in the metropolis

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    Introduction. Invasive listeriosis is a rare disease posing a threat to high-risk groups and often leading to a fatal outcome. Its causative agent is Listeria monocytogenes, a ubiquitous saprophyte that has turned into an important foodborne pathogen with the growing industry of semi-cooked and ready-to-eat products. The aim of the study is the characterization of L. monocytogenes isolates in the Moscow region and identification of possible causes of susceptibility to infection Materials and methods. The multicenter monitoring of L. monocytogenes was conducted in the Moscow metropolitan area, using bacteriological and genomic methods for description of the pathogen, medical history collection and detailed analysis of patient case summaries. Results. In the cohorts of patients with perinatal listeriosis (PL) and meningitis-septicemia (MS), invasive listeriosis had a year-round occurrence with slight upswings in MarchApril and JulyNovember. During the COVID-19 pandemic, in the MS group, the minimum age of patients decreased to 31 years and the proportion of deaths increased 1.57-fold compared to 20182019. During the pandemic, an increase in the diversity of L. monocytogenes genotypes was observed, along with changes in the spectrum of pathogen genotypes throughout the pandemic stages. During the monitoring, a total of 73 L. monocytogenes clinical isolates belonging to 24 genotypes were described. Seven genotypes belonged to the first phylogenetic lineage (PLI); 14 genotypes belonged to PLII. The PL cohort had the highest proportion of PLI genotypes (52%). In the MS cohort, the group of men had the widest diversity of genotypes, 6 of which were identical to genotypes of food isolates. In the analysed set of isolates, 12 new profiles of internalin genes were identified and described. The whole genome sequencing detected the presence of plasmids in 9 of 58 genomes of clinical isolates. The comparison of core genomes revealed an epidemic relationship between isolates of the same genotype for ST4, ST21, and ST425. Conclusion. The performed study presents a detailed description of the diversity and virulence of L. monocytogenes circulating in the Moscow metropolitan area, thus providing information for timely diagnosis and treatment of invasive listeriosis

    Effective transcription factor binding site prediction using a combination of optimization, a genetic algorithm and discriminant analysis to capture distant interactions

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    <p>Abstract</p> <p>Background</p> <p>Reliable transcription factor binding site (TFBS) prediction methods are essential for computer annotation of large amount of genome sequence data. However, current methods to predict TFBSs are hampered by the high false-positive rates that occur when only sequence conservation at the core binding-sites is considered.</p> <p>Results</p> <p>To improve this situation, we have quantified the performance of several Position Weight Matrix (PWM) algorithms, using exhaustive approaches to find their optimal length and position. We applied these approaches to bio-medically important TFBSs involved in the regulation of cell growth and proliferation as well as in inflammatory, immune, and antiviral responses (NF-κB, ISGF3, IRF1, STAT1), obesity and lipid metabolism (PPAR, SREBP, HNF4), regulation of the steroidogenic (SF-1) and cell cycle (E2F) genes expression. We have also gained extra specificity using a method, entitled SiteGA, which takes into account structural interactions within TFBS core and flanking regions, using a genetic algorithm (GA) with a discriminant function of locally positioned dinucleotide (LPD) frequencies.</p> <p>To ensure a higher confidence in our approach, we applied resampling-jackknife and bootstrap tests for the comparison, it appears that, optimized PWM and SiteGA have shown similar recognition performances. Then we applied SiteGA and optimized PWMs (both separately and together) to sequences in the Eukaryotic Promoter Database (EPD). The resulting SiteGA recognition models can now be used to search sequences for BSs using the web tool, SiteGA.</p> <p>Analysis of dependencies between close and distant LPDs revealed by SiteGA models has shown that the most significant correlations are between close LPDs, and are generally located in the core (footprint) region. A greater number of less significant correlations are mainly between distant LPDs, which spanned both core and flanking regions. When SiteGA and optimized PWM models were applied together, this substantially reduced false positives at least at higher stringencies.</p> <p>Conclusion</p> <p>Based on this analysis, SiteGA adds substantial specificity even to optimized PWMs and may be considered for large-scale genome analysis. It adds to the range of techniques available for TFBS prediction, and EPD analysis has led to a list of genes which appear to be regulated by the above TFs.</p

    TRAINING TECHNOLOGY TO OVERCOME ADAPTATION BARRIERS

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    The authors dwell on training technology aimed at overcoming adaptation barriers by first-year students. Specially organized training promotes development of educational professional activity, development of students’ self-understanding. The article describes the main barriers arising during the period of adaptation of first-year students to educational professional activity. Among them are: the low level of self-understanding, fear of entry into a new group, unformed professional intentions, the low level of self-checking, lack of skills of constructive interaction. Stages of training adaptation work on overcoming of these barriers are given. The results of assessment the efficiency of the training technology are presented. Students who have completed the course of social and psychological adaptation increase their level of self-understanding, internal motivation to educational professional activity, self-checking, self-control, self-management, constructive interaction. Thus, the adaptation training is an effective technology to overcome the barriers to development of educational professional activity, self-understanding and effective communication by first-year students

    Personal characteristics and environmentally responsible behavior of children of the generation alpha with different leisure orientation

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    The problem of the influence of macrosocial factors that determine the trends of psychological development of entire generations of children is a unique opportunity to highlight the psychological and pedagogical conditions that have remained in the shadow of the general «ensemble» of factors. It was suggested that the specifics of leisure activities of preschool children of the Generation Alpha in the conditions of forced epidemiological self-isolation affects intrapersonal structures, their resource state and it is associated with the dominant system of child-parent relations in the family. The empirical study of the dyad «child of 5-7 years-parent» (N=72 and N=72) was conducted using projective diagnostic methods: children's anxiety was analyzed, self-assessment; blank diagnostic methods for assessing the organization of family leisure and child-parent relations. The study showed the emergence of two new forms of free leisure activities for children: virtual and mixed (virtual activity and traditional communication with peers). The dependence of the level of children's immersion in digital gadgets with an increase of their anxiety and a decrease of self-esteem, difficulties with resource recovery was revealed. It is concluded that in families where children spend virtual leisure time, child-parent relations are characterized by a reduced level of acceptance of the child, the desire for cooperation and symbiosis with him. The results obtained are of interest for solving the problems of designing conditions for the psychological and pedagogical development of children of the Generation Alpha as well as training specialists in the field of child practical psychology
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