140 research outputs found

    The microscopic basis for phase-sensitive experiments for determination of the order parameter symmetry in Fe-based superconductors

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    We present a microscopic theory of dc Josephson current, based on the construction of a coherent temperature Green function in the tight-binding approximation, in junctions with multiband superconductors. This theory is applied to the junctions with multiband Fe-based superconductors (FeBS) described by anisotropic s-wave order parameter symmetries, which probably realized in FeBS. We confirm microscopically the previously suggested crucial experiment for determination of the type of the order parameter symmetry in FeBS.Comment: 5 pages, 3 figure

    Anomalous superconducting proximity effect and coherent charge transport in semiconducting thin film with spin-orbit interaction

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    We present a microscopic theory of the superconducting proximity effect in a semiconducting thin film with spin-orbit interaction (NSON_{SO}) in an external magnetic field. We demonstrate that an effective 1D Hamiltonian which describes induced superconductivity in NSON_{SO} in contact with a usual ss-wave superconductor possesses not only spin-singlet induced superconducting order parameter term, as commonly adopted, but spin triplet order parameter term also. Using this new effective Hamiltonian we confirm previous results for a normal current across contacts of NSON_{SO} with a normal metal and for a Josephson current with the same NSON_{SO} with induced superconductivity, obtained previously in the framework of the phenomenological Hamiltonian without spin-triplet terms. However, a calculated current-phase relation across the transparent contact between NSON_{SO} with induced superconductivity in magnetic field and usual ss-wave superconductor differs significantly from previous results. We suggest the experiment which can confirm our theoretical predictions.Comment: 5 pages, 6 figure

    The transformations of thiols and their dimers in the redox-mediated thiol-disulfide exchange reaction

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    A search for new approaches to sulfurous waste utilization is one of the urgent tasks of chemical technology. Thiol-disulfide exchange reaction (TDE) is one of the possible ways to involve technogenic wastes in organic synthesis. Electricity can promote such type of interactions. In this paper, we have studied TDE reactions involving low molecular weight thiols or their dimers under electrochemical conditions. The exchange processes were examined using the model reaction between 1-propanethiol and phenyl disulfide. Electrolysis was performed in the presence of redox mediators such as arylphosphines, substituted amines, o-, p-aminophenols or catechol. These compounds can initiate a TDE process with a formation of unsymmetrical disulfides. 4-Amino-2,6-diphenylphenol was chosen as the most effective redox mediator, which reduces the anodic overvoltage of a thiol oxidation by 1.20 V. The advantage of electrolysis in an undivided cell is the increased yield of target unsymmetrical disulfides due to the possibility of reduction ofhomodimers at the cathode. The involvement of refining waste, such as C3–C4 disulfide oil, in the reaction with substituted thiophenols made it possible to obtain a number of unsymmetrical arylalkyl disulfides with biologically active fragments in a high yield (up to 97%) under indirect electrolysis conditions

    The Josephson current in Fe-based superconducting junctions: theory and experiment

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    We present theory of dc Josephson effect in contacts between Fe-based and spin-singlet ss-wave superconductors. The method is based on the calculation of temperature Green's function in the junction within the tight-binding model. We calculate the phase dependencies of the Josephson current for different orientations of the junction relative to the crystallographic axes of Fe-based superconductor. Further, we consider the dependence of the Josephson current on the thickness of an insulating layer and on temperature. Experimental data for PbIn/Ba1x_{1-x}Kx_{x}(FeAs)2_2 point-contact Josephson junctions are consistent with theoretical predictions for s±s_{\pm} symmetry of an order parameter in this material. The proposed method can be further applied to calculations of the dc Josephson current in contacts with other new unconventional multiorbital superconductors, such as Sr2RuO4Sr_2RuO_4 and superconducting topological insulator CuxBi2Se3Cu_xBi_2Se_3.Comment: 16 pages, 14 figure

    Woodworking facilities: Driving efficiency through Automation applied to major process steps

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    The investment scenario applied to forestry development analyzes the fundamental changes in the production structure, among other things. These changes refer to the priority development of the pulp and paper industry through the chain of large-scale woodworking facilities, where pulp, paper and cardboard manufacturing plants are the key links. Such facilities include sawmilling facilities, wood-processing factories, and timber factories. Those provide a significant economic benefit, so improving them is one of the top priorities. Considering this priority is the purpose of this article. The goal was achieved using common and scientific research methods, including mathematical modeling. Theoretical research resulted in three sets of formulas adapted for evaluating the pulpwood barking from theoretical findings on image recognition. © 2018 Authors

    Combinations of proinflammatory cytokine genes and their interactions in Russian tuberculosis patients in the Chelyabinsk Region

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    Tuberculosis is a widespread infectious disease caused by M. tuberculosis, which is one of the leading causes of death  in the world.  According to numerous literature data,  this is a genetically determined disease, and genetical polymorphism is a mechanism that leads to progression from infection to clinical  manifestation. Susceptibility to infection correlates with different genes at several loci, and each individual gene plays a unique role. It is known, that  the analysis of individual polymorphic variants  of genes does not provide  a sufficiently complete picture of the  mechanisms of formation of a predisposition to multifactorial pathologies, such  as tuberculosis, since  their  development is based  on complex intergenic and  gene-environmental interactions, which  must  be taken  into  account when  predicting the  risk of developing active  forms of the  disease  and  its severity. The concept of the functioning of cytokines as biomarkers of tuberculosis suggests that their products and interactions play an important role in the immunopathogenesis of the disease, because they form a cytokine chain  with  unique  functions, where  the  removal  of any  link in the  chain  disrupts  the  entire  mechanism of the  immuno-inflammatory process.  IL-6, together with  TNFα and  IL-1β, initiate early  pro-inflammatory reactions in  tuberculosis, stimulating local  and  systemic  inflammatory reactions under  participation of all common pro-inflammatory mechanisms with further  transition to activation of acquired immunity. Earlier, we carried  out a set of studies to evaluate  the association of alleles and genotypes  of these cytokine genes with a predisposition/resistance to pulmonary tuberculosis in Russians  of the  Chelyabinsk region.  These  studies have resulted  into assessment of certain distribution patterns of IL-1β, TNFα, IL-6  alleles and their genotypes in pulmonary tuberculosis and its various clinical  forms. The following methods were used: isolation of DNA samples  from whole blood,  genotyping of the studied  gene polymorphisms using PCR  and RFLP techniques. In this study, we analyzed  the intergenic interactions of the genes for the pro-inflammatory cytokines IL-1β, TNFα, IL-6 using the method of reducing multifactor dimension in patients with pulmonary tuberculosis. The program designs optimal models  of combinations for the studied  genes and their  interactions in tuberculosis patients. As a result of this study, a three-locus model  IL-6  (-174)*С – IL-1β (+3953)*Т – IL-1β (+3953)*С was established, which was characterized by 100% reproducibility and prediction accuracy of 72%. Among the analyzed  polymorphisms, the  IL-6  (-174)*C polymorphism possessed  the  highest  predictive potential with 15.27%

    Using Machine Vision to Improve the Efficiency of Lumber Mills

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    This work provides rationale for the implementation of a machine vision-based approach for promoting timber processing efficiency. With efforts to combat the climate change, criteria for the success of wood industries shifted. Now, they need to ensure economic efficiency while taking the reduction in carbon intensity into account. This may be achieved in either of two ways, through the improvement of energy efficiency in production and by minimizing waste. So far, the traditional methods for the improvement of timber processing efficiency became obsolete. Hence, using advances in electronic engineering and machine vision may be viewed as a promising step. © Published under licence by IOP Publishing Ltd

    INTERGENIC INTERACTIONS OF CYTOKINE GENES IL1, IL1RA, IL6, IL10 AND TNFА IN PATIENTS WITH IRRITABLE BOWEL SYNDROME AND ULCERATIVE COLITIS IN RUSSIAN POPULATION OF THE CHELYABINSK REGION

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    Сomplex intergenic interactions should be taken into account when predicting the risk of adverse course in a pathological process. This presumption is at the heart of evolving multifactorial diseases (ulcerative colitis and irritable bowel syndrome). A single genetic polymorphism seems to be a weak risk factor when predicting the disease evolution and it could not be used as a prognostic model for development of multifactorial pathologies, especially in cases of rare alleles. However, it is well known that the combination of unfavorable alleles of several genes with an additive effect is dangerous. Therefore, identification of such polymorphisms is very important.Previously we conducted a test panel, in order to evaluate associations of alleles and genotypes of some cytokine genes (IL1β, TNFα, IL1rа, IL10, IL6) with predisposal, or resistance for ulcerative colitis and irritable bowel syndrome in the Russian Chelyabinsk region. Distribution of alleles and genotypes of these genes have been assessed in irritation bowel disease (IBD) and ulcerative colitis (UC). The following methods were used: isolation of DNA samples from whole blood, genotyping of the studied gene polymorphisms with PCR, RFLP. A comparative analysis of intergenic interactions between the cytokine genes IL1β, TNFα, IL1ra, IL10, IL6 in the IBD and UC patients was carried out by the Multifactor Dimensionality Reduction method. The analysis is based on the use of polymorphic loci of IL1β, TNFα, IL1ra, IL10, IL6 combinations chosen for analysis of intergenic interactions, with respect to the risk for IBS and UC predisposition. As a result of this study, a fourlocus model IL1β(+3953)*Т/TNFα(-308)*A/IL10(-1082)*G/IL6(-174)*G was identified for IBS, which was characterized by 90% repeatability and prediction accuracy of 74.5%. This model of gene interactions between the cytokine IL1β, TNFα, IL1ra, IL10, IL6 genes had the greatest prediction potential (p < 0.001) in IBS, whereas the model for UC was not statistically significant. The following types of genetic interactions were established: synergism between the IL1β(+3953)*Т and TNFα(-308)*A loci, whereas IL6(-174)*G и IL10(-1082)*G, TNFα(-308)*A seem to be in antagonistic relationships. The study made it possible to establish that the -174G/C IL-6 polymorphism may play a central role and provide intergenic interactions with SNPs of IL1β, TNFα, IL10 for predisposal to irritable bowel syndrome in Chelyabinsk Region of Russia

    Saliva versus plasma cytokines as possible predictors of autism severity

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    The autism spectrum disorders (ASD) are now widely accepted as a pervasive, complex, heterogeneous neurodevelopmental disorders with multiple etiologies, subtypes, and developmental trajectories. There are no available and effective biomarkers for them. Immune dysfunction is seen as an important risk factor contributing to the neurodevelopmental deficit in ASD, and is signified, among other things, by an imbalance of cytokines in the brain and on the periphery. In recent years, saliva has been proposed as a biological material for diagnosing ASD, due to the accessibility and non-invasiveness of the method for its production. However, the question of whether salivary cytokine levels may be used as effective early biomarkers for autism requires further research, including saliva versus plasma/serum comparisons.Aim: a comparative analysis of the levels of cytokines: IL-6, IFNγ, TNFα, IL-1β, IL-4, IL-10, in saliva and blood plasma to identify possible markers of ASD and their severity in children.The study included 11 children with typical neurodevelopment (TDC) and 55 children with ASD, among whom 37 children had mild or moderate autism (according to CARS), and 18 children had severe autism. Samples of unstimulated mixed saliva and venous blood were simultaneously collected from all children. Salivary concentrations of cytokines: IL-6, IFNγ, TNFα, IL-1β, IL-4, IL-10 were determined by multiplex Luminex™ analysis. Plasma levels of cytokines were assessed by ELISA. Differences between groups were tested using the Kruskal-Wallis U-test with post-hoc Conover-Inman comparisons, between samples (saliva/ plasma) are using the Wilcoxon signed-rank test. The correlation between the concentrations of cytokines in plasma and saliva was determined using linear regression by the RMA method.In all examined groups, the levels of IL-6, IFNγ and IL-10 in saliva were significantly lower, and TNFα, IL-1β and IL-4 were higher than the corresponding levels of the same cytokines in plasma. Regardless of health/ disease status, no significant correlations were found between salivary and plasma cytokine levels in children. IL-1β levels were significantly lower and IL-10 levels were higher in the saliva of both groups of children with ASD compared with TDC. No significant differences in salivary cytokine concentrations were found between children with mild and severe ASD.Thus, salivary cytokines can be used as markers of ASD in children, but not the severity of the condition. The absence of correlations in the levels of some pro/anti-inflammatory cytokines between saliva and blood plasma may probably indicate a special immunological status of an ecological niche, the oral cavity
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