22 research outputs found

    Analysis of approaches to assessing the actual condition, residual life and reliability of hydraulic turbines

    Get PDF
    In order to increase the resource and reliability of power equipment, reduce downtime and repair costs, modern methods of monitoring and resource diagnostics are used to build an equipment maintenance system based on the actual technical condition of the equipment. The main content of the work performed with different prevention strategies is considered. The current situation with the wear of the main power equipment in the country and the results of research indicate the need to create and develop more advanced methods for assessing the resource of power equipment both in hydropower and in the energy sector as a whole

    Assessment of the level of reliability and safety based on the index of the technical condition of the equipment of energy systems

    Get PDF
    results of evaluation and forecasting of reliability indicators of technological equipment are presented on the basis of a neural network model for calculating fault-free operation indicators taking into account safety indicators of the generating system. In the process of creating a neural network, a topology was developed, a mechanism for training and testing the model was determined. During the study, a sample of input data was created, an algorithm for functioning and data exchange was built. The analysis of statistical data on the joint influence of a number of parameters of technical condition of resource-determining functional units on their index of technical condition, on the general technical condition of the hydraulic unit, which showed that the most confirmed are the joint effect of increasing the pressure difference in the servomotor cavities and increasing the pressure difference in the servomotor cavitation erosion of the blades in the flow part of the hydraulic unit. Multivariate data bases formed by the neural network model, combining the effect of blade turning on the change in the probability of hydraulic power equipment failure, impact of shaft combat on the index of technical condition of the unit “turbine bearing and shaft,” influence of shaft vibration change on index of technical condition of hydraulic power equipment and turbine cover, and taking into account the park life, inter-repair period, accident rate, metal condition should be used to create prognostic models that provide approaches to extending the operable state of elements of hydropower equipment. Obtained results can be used in creation of modern systems of monitoring and diagnostics of power equipment, its separate elements required for collection, storage, archiving of data taking into account actual state of specific element of hydraulic unit for qualitative prediction of indicators of reliability of hydropower equipment in order to increase efficiency of operation of generating and power systems

    Biallelic MFSD2A variants associated with congenital microcephaly, developmental delay, and recognizable neuroimaging features

    Get PDF
    Major Facilitator Superfamily Domain containing 2a (MFSD2A) is an essential endothelial lipid transporter at the blood-brain barrier. Biallelic variants affecting function in MFSD2A cause autosomal recessive primary microcephaly 15 (MCPH15, OMIM# 616486). We sought to expand our knowledge of the phenotypic spectrum of MCPH15 and demonstrate the underlying mechanism of inactivation of the MFSD2A transporter. We carried out detailed analysis of the clinical and neuroradiological features of a series of 27 MCPH15 cases, including eight new individuals from seven unrelated families. Genetic investigation was performed through exome sequencing (ES). Structural insights on the human Mfsd2a model and in-vitro biochemical assays were used to investigate the functional impact of the identified variants. All patients had primary microcephaly and severe developmental delay. Brain MRI showed variable degrees of white matter reduction, ventricular enlargement, callosal hypodysgenesis, and pontine and vermian hypoplasia. ES led to the identification of six novel biallelic MFSD2A variants (NG_053084.1, NM_032793.5: c.556+1G>A, c.748G>T; p.(Val250Phe), c.750_753del; p.(Cys251SerfsTer3), c.977G>A; p.(Arg326His), c.1386_1435del; p.(Gln462HisfsTer17), and c.1478C>T; p.(Pro493Leu)) and two recurrent variants (NM_032793.5: c.593C>T; p.(Thr198Met) and c.476C>T; p.(Thr159Met)). All these variants and the previously reported NM_032793.5: c.490C>A; p.(Pro164Thr) resulted in either reduced MFSD2A expression and/or transport activity. Our study further delineates the phenotypic spectrum of MCPH15, refining its clinical and neuroradiological characterization and supporting that MFSD2A deficiency causes early prenatal brain developmental disruption. We also show that poor MFSD2A expression despite normal transporter activity is a relevant pathomechanism in MCPH15

    Results of implementation of viral hepatitis B elimination program in the North-West Russia

    Get PDF
    Introduction. Vaccination contributed to reduce the incidence of acute hepatitis B in the territories of the North-West Russia. The urgency of this problem remains due to the high incidence of chronic hepatitis B. This accounted for the need to develop a hepatitis B elimination program in the district discussed that was approved in 2013 by the head of the Federal Service for Surveillance on Consumer Rights Protection and Human Wellbeing. Objective is to characterize the results of the program for the elimination of acute hepatitis B virus implemented in the North-Western Federal District. Materials and methods. The 2010–2020 incidence rate of acute and chronic hepatitis B virus (HBV) infection in the regions of the North-West Russia was carried out. To determine HBV genotypes and subgenotypes, 160 blood plasma samples from patients with acute hepatitis B were studied using molecular genetic methods (PCR, sequencing). The prevalence of latent hepatitis B in various population groups was assessed. The 2016–2020 hepatitis B vaccination coverage and relevant serological monitoring in adults was carried out. Results. While implementing the program, it was found that the incidence rate of acute hepatitis B in the district decreased by 4.5-fold, revealing in 2020 no cases of the disease in 5 regions, with incidence rate in the 6 subfederal units being lower than 1.0 per 100,000 population. Moreover, the incidence rate for chronic hepatitis B decreased by 2.6 times. The 2020 vaccination coverage of children under 17 and adults in all territories comprised more than 95% and 90%, respectively. In addition, it was shown the circulation of genotypes D and A of hepatitis B virus is dominated by genotype D (91.8%), subgenotype D2 (47.8%). The prevalence of latent hepatitis B among migrants was 6.5%, pregnant women — 4.9%, hemodialysis patients — 1.7%. Conclusion. Implementation of the program on elimination of acute viral hepatitis B in the territory of the North-West Russia contributed to raise in the vaccination coverage in adult population and lowered incidence rate of acute and chronic HBV infection

    Chronic visceral acid sphingomyelinase deficiency (Niemann-Pick disease type B) in 16 Polish patients: long-term follow-up

    No full text
    Abstract Background Acid sphingomyelinase deficiency (ASMD), due to mutations in the sphingomyelin phosphodiesterase 1 (SMPD1) gene, is divided into infantile neurovisceral ASMD (Niemann-Pick type A), chronic neurovisceral ASMD (intermediate form, Niemann-Pick type A/B) and chronic visceral ASMD (Niemann-Pick type B). We conducted a long-term observational, single-center study including 16 patients with chronic visceral ASMD. Results 12 patients were diagnosed in childhood and 4 others in adulthood, the oldest at the age of 50. The mean time of follow-up was approximately 10 years (range: 6 months – 36 years). Splenomegaly was noted in all patients at diagnosis. Hepatomegaly was observed in 88% of patients. Moderately elevated (several-fold above the upper limit of normal values) serum transaminases were noted in 38% of patients. Cherry-red spots were found in five Gypsy children from one family and also in one adult Polish patient, a heterozygote for p.delR610 mutation. Dyslipidemia was noted in 50% of patients. Interstitial lung disease was diagnosed in 44% of patients. Plasmatic lysosphingomyelin (SPC) was elevated in all the patients except one with p.V36A homozygosity and a very mild phenotype also presenting with elevated plasmatic SPC-509 but normal chitotriosidase activity. The most common variant of SMPD1 gene was p.G166R. We found a previously unreported variant in exon 2 (c.491G > T, p.G164 V) in one patient. Conclusions Chronic visceral ASMD could constitute a slowly progressing disease with a relatively good outcome. The combined measurement of lysosphingomyelin (SPC) and lysospingomyelin-509 (SPC-509) is an essential method for the assessment of ASMD course

    Analysis of approaches to assessing the actual condition, residual life and reliability of hydraulic turbines

    No full text
    In order to increase the resource and reliability of power equipment, reduce downtime and repair costs, modern methods of monitoring and resource diagnostics are used to build an equipment maintenance system based on the actual technical condition of the equipment. The main content of the work performed with different prevention strategies is considered. The current situation with the wear of the main power equipment in the country and the results of research indicate the need to create and develop more advanced methods for assessing the resource of power equipment both in hydropower and in the energy sector as a whole

    Assessment of the level of reliability and safety based on the index of the technical condition of the equipment of energy systems

    No full text
    results of evaluation and forecasting of reliability indicators of technological equipment are presented on the basis of a neural network model for calculating fault-free operation indicators taking into account safety indicators of the generating system. In the process of creating a neural network, a topology was developed, a mechanism for training and testing the model was determined. During the study, a sample of input data was created, an algorithm for functioning and data exchange was built. The analysis of statistical data on the joint influence of a number of parameters of technical condition of resource-determining functional units on their index of technical condition, on the general technical condition of the hydraulic unit, which showed that the most confirmed are the joint effect of increasing the pressure difference in the servomotor cavities and increasing the pressure difference in the servomotor cavitation erosion of the blades in the flow part of the hydraulic unit. Multivariate data bases formed by the neural network model, combining the effect of blade turning on the change in the probability of hydraulic power equipment failure, impact of shaft combat on the index of technical condition of the unit “turbine bearing and shaft,” influence of shaft vibration change on index of technical condition of hydraulic power equipment and turbine cover, and taking into account the park life, inter-repair period, accident rate, metal condition should be used to create prognostic models that provide approaches to extending the operable state of elements of hydropower equipment. Obtained results can be used in creation of modern systems of monitoring and diagnostics of power equipment, its separate elements required for collection, storage, archiving of data taking into account actual state of specific element of hydraulic unit for qualitative prediction of indicators of reliability of hydropower equipment in order to increase efficiency of operation of generating and power systems

    New Acylcarnitine Ratio as a Reliable Indicator of Long-Chain 3-Hydroxyacyl-CoA Dehydrogenase Deficiency

    No full text
    Long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) and mitochondrial trifunctional protein (MTP) deficiencies are rare fatal disorders of fatty acid β-oxidation with no apparent genotype–phenotype correlation. The measurement of acylcarnitines by MS/MS is a current diagnostic workup in these disorders. Nevertheless, false-positive and false-negative results have been reported, highlighting a necessity for more sensitive and specific biomarkers. This study included 54 patients with LCHAD/MTP deficiency that has been confirmed by biochemical and molecular methods. The analysis of acylcarnitines in dried blood spots was performed using ESI-MS/MS. The established “HADHA ratio” = (C16OH + C18OH + C18:1OH)/C0 was significantly elevated in all 54 affected individuals in comparison to the control group. Apart from 54 LCHAD deficiency patients, the “HADHA ratio” was calculated in 19 patients with very-long-chain acyl-CoA dehydrogenase (VLCAD) deficiency. As VLCAD-deficient patients did not show increased “HADHA ratio”, the results emphasized the high specificity of this new ratio. Therefore, the “HADHA ratio” was shown to be instrumental in improving the overall performance of MS/MS-based analysis of acylcarnitine levels in the diagnostics of LCHAD/MTP deficiencies. The ratio was demonstrated to increase the sensitivity and specificity of this method and reduce the chances of false-negative results

    Functional Analysis of the PCCA and PCCB Gene Variants Predicted to Affect Splicing

    No full text
    It is estimated that up to one-third of all variants causing inherited diseases affect splicing; however, their deleterious effects and roles in disease pathogenesis are often not fully characterized. Given their prevalence and the development of various antisense-based splice-modulating approaches, pathogenic splicing variants have become an important object of genomic medicine. To improve the accuracy of variant interpretation in public mutation repositories, we applied the minigene splicing assay to study the effects of 24 variants that were predicted to affect normal splicing in the genes associated with propionic acidemia (PA)—PCCA and PCCB. As a result, 13 variants (including one missense and two synonymous variants) demonstrated a significant alteration of splicing with the predicted deleterious effect at the protein level and were characterized as spliceogenic loss-of-function variants. The analysis of the available data for the studied variants and application of the American College of Medical Genetics and the Association for Molecular Pathology (ACMG/AMP) guidelines allowed us to precisely classify five of the variants and change the pathogenic status of nine. Using the example of the PA genes, we demonstrated the utility of the minigene splicing assay in the fast and effective assessment of the spliceogenic effect for identified variants and highlight the necessity of their standardized classification

    Hyperammonemia in Russia Due to Carbonic Anhydrase VA Deficiency Caused by Homozygous Mutation p.Lys185Lys (c.555G>A) of the <i>CA5A</i> Gene

    No full text
    Hyperammonemia due to carbonic anhydrase VA deficiency (OMIM# 615751) is a rare, life-threatening hereditary disease caused by biallelic mutations in the CA5A gene, presenting as encephalopathic hyperammonemia of unexplained origin during the neonatal period and infancy. Here, we present a detailed description of a 5-year-old patient with the homozygous mutation p.Lys185Lys (c.555G>A) in the CA5A gene. This variant was previously described by van Karnebeek et al. in 2014 in a boy of Russian origin. We found a high frequency of carriers of this mutation in Russia; 1:213, which is 7 times higher than the expected frequency calculated based on data on Western European populations. Thus, targeted testing for the mutation p.Lys185Lys (c.555G>A) in the CA5A gene should be useful for early detection by selective screening in neonatal intensive care units
    corecore