Improvement of protective oxide layers formed by high-frequency plasma electrolytic oxidation on Mg-RE alloy with LPSO-phase

Oxide layers on Mg97Y2Zn1 magnesium alloy with strengthening LPSO-phase were formed by plasma electrolytic oxidation (PEO) in bipolar mode with frequency variation of forming current pulses (50 and 500 Hz) and addition of sodium aluminate or sodium silicate to alkali phosphate fluoride electrolyte. Microstructure, chemical and phase composition, corrosion and mechanical properties of the oxide layers formed were investigated. With increasing current frequency for both electrolytes, an increase in homogeneity of the oxide layers structure and a decrease in their porosity and fracturing at constant thickness were recorded. The oxide layers formed at 500 Hz even with some decrease in hardness have better adhesive strength and 2 orders of magnitude higher short-term corrosion resistance values. PEO of Mg-alloy with LPSO-phase in the electrolyte with addition of sodium aluminate in combination with increased pulse frequency (500 Hz) allows forming the best-quality uniform oxide layer with high hardness, adhesive strength and corrosion resistance properties. The use of electrolyte with addition of sodium silicate reduced the adhesive strength by 1.5 times and brought down the long-term corrosion resistance of oxide layers by an order of magnitude, as compared with the electrolyte with sodium aluminate. The reason for a significant improvement in the complex of protective properties of the oxide layers with an increase in the current pulse frequency is supposed to be a decrease in the power and duration of individual microarc discharges with simultaneous increase in their number per unit oxidized area

A community resource for paired genomic and metabolomic data mining

Genomics and metabolomics are widely used to explore specialized metabolite diversity. The Paired Omics Data Platform is a community initiative to systematically document links between metabolome and (meta)genome data, aiding identification of natural product biosynthetic origins and metabolite structures.Peer reviewe

AI is a viable alternative to high throughput screening: a 318-target study

: High throughput screening (HTS) is routinely used to identify bioactive small molecules. This requires physical compounds, which limits coverage of accessible chemical space. Computational approaches combined with vast on-demand chemical libraries can access far greater chemical space, provided that the predictive accuracy is sufficient to identify useful molecules. Through the largest and most diverse virtual HTS campaign reported to date, comprising 318 individual projects, we demonstrate that our AtomNet® convolutional neural network successfully finds novel hits across every major therapeutic area and protein class. We address historical limitations of computational screening by demonstrating success for target proteins without known binders, high-quality X-ray crystal structures, or manual cherry-picking of compounds. We show that the molecules selected by the AtomNet® model are novel drug-like scaffolds rather than minor modifications to known bioactive compounds. Our empirical results suggest that computational methods can substantially replace HTS as the first step of small-molecule drug discovery

Electrophysiological and Structural Remodeling in Heart Failure Modulate Arrhythmogenesis. 1D Simulation Study

Background: Heart failure is a final common pathway or descriptor for various cardiac pathologies. It is associated with sudden cardiac death, which is frequently caused by ventricular arrhythmias. Electrophysiological remodeling, intercellular uncoupling, fibrosis and autonomic imbalance have been identified as major arrhythmogenic factors in heart failure etiology and progression. Objective: In this study we investigate in silico the role of electrophysiological and structural heart failure remodeling on the modulation of key elements of the arrhythmogenic substrate, i.e., electrophysiological gradients and abnormal impulse propagation. Methods: Two different mathematical models of the human ventricular action potential were used to formulate models of the failing ventricular myocyte. This provided the basis for simulations of the electrical activity within a transmural ventricular strand. Our main goal was to elucidate the roles of electrophysiological and structural remodeling in setting the stage for malignant life-threatening arrhythmias. Results: Simulation results illustrate how the presence of M cells and heterogeneous electrophysiological remodeling in the human failing ventricle modulate the dispersion of action potential duration and repolarization time. Specifically, selective heterogeneous remodeling of expression levels for the Na+ /Ca2+ exchanger and SERCA pump decrease these heterogeneities. In contrast, fibroblast proliferation and cellular uncoupling both strongly increase repolarization heterogeneities. Conduction velocity and the safety factor for conduction are also reduced by the progressive structural remodeling during heart failure. Conclusion: An extensive literature now establishes that in human ventricle, as heart failure progresses, gradients for repolarization are changed significantly by protein specific electrophysiological remodeling (either homogeneous or heterogeneous). Our simulations illustrate and provide new insights into this. Furthermore, enhanced fibrosis in failing hearts, as well as reduced intercellular coupling, combine to increase electrophysiological gradients and reduce electrical propagation. In combination these changes set the stage for arrhythmias.This work was partially supported by (i) the "VI Plan Nacional de Investigacion Cientifica, Desarrollo e Innovacion Tecnologica" from the Ministerio de Economia y Competitividad of Spain (grant number TIN2012-37546-C03-01) and the European Commission (European Regional Development Funds - ERDF - FEDER), (ii) the Direccion General de Politica Cientifica de la Generalitat Valenciana (grant number GV/2013/119), and (iii) Programa Prometeo (PROMETEO/2012/030) de la Conselleria d'Educacio Formacio I Ocupacio, Generalitat Valenciana. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Gómez García, JF.; Cardona, K.; Romero Pérez, L.; Ferrero De Loma-Osorio, JM.; Trénor Gomis, BA. (2014). Electrophysiological and Structural Remodeling in Heart Failure Modulate Arrhythmogenesis. 1D Simulation Study. PLoS ONE. 9(9). https://doi.org/10.1371/journal.pone.0106602S9

EXPERIMENTAL INVESTIGATION OF THERMAL CONVECTION IN MIXTURES UNDER CONDITIONS OF THE GRAVITATION SEPARATION

The thermal convection of liquid binary mixtures and magnetic colloids under conditions, when there is a concentration gradient in a liquid at the same time with a temperature gradient and the mechanism of the support of this gradient exists due to the gravitation sedimentation of brown magnetic particles, their units or macroscopic heterogeneities of concentration, has been investigated in the paper. Temperature dields have been measured. The concentration distribution in magnetic liquids has been investigated. Speeds of convection flows have been measured. The theoretical analysis has been held. The influence of gravitation gradients of concentration on convection flows under conditions of the side and lower heating has been detected and investigated for the first time. The oscillatory instability and oscillatory regimes of convection near the crisis of the stable equilibrium have been investigatedAvailable from VNTIC / VNTIC - Scientific & Technical Information Centre of RussiaSIGLERURussian Federatio

“Geography of Human Perspectives” Program as an Educational and Methodological Complex for Spatial Self-determination

The relevance of the issue. Today, special attention is paid to new literacy and skills of the 21st century as those define individual and activity-based acquisition of knowledge. Within the framework of new types of outcomes it is necessary to change not only the techniques and methods of teaching, but also to update the content, forms of learners’ work, to change the types and nature of tasks that are stated in the syllabus of educational disciplines. The example of implementation of the program "Geography of Human Perspectives" as an elective course demonstrates the experience of a comprehensive revision of approaches to teaching economic geography. This paper presents some results of approbation of this program, which highlight the pros and cons of this kind of modernization of the educational process. The purpose of the study: to identify the structural and content elements of the elective educational program "Geography of Human Perspectives", which can be used to support the self-determination and development of high school students’ interests. The dominant methodology / approach: ascertaining experiment accompanied by specially organized diagnostic procedures. Results: identification of successful methods of organizing educational activities, which are based on the individual interests of students; establishment of a mechanism for presenting the subject "geography" as a means of self-determination for high school students. Practical significance: this paper will serve as basis for elaboration of recommendations for the development of elective courses and programs of supplementary education for children

On thermodiffusion influence on the dopant distribution during the freezing of binary liquid column

The relevance of the study is caused by the necessity of the extension of fundamental experimental and theoretical research in the field of macroscopic hydrodynamic phenomena in multicomponent liquid molecular mixtures. The results can be used in chemical technologies; they can change our point of view on the processes of deep waste water reclamation and safe utilization of geological resources. The main aim is to investigate the phenomenon of liquid molecular mixtures separation in thin channels by means of thermodiffusion over the self-cooling procedure; to compare different mechanisms of transfer - convection of short duration, diffusion and thermodiffusion - on the process of the components redistribution in the thin columns filled with a water-salt solution. The undertaken investigation has been executed to explain the origination of appreciable vertical stratification of different components of the mixture that gives significant variability of water salinity along the channel height. The methods used in the study: to fulfill the plan of our research the experimental and theoretical methods had been used that simulated physical processes under consideration: experimental data on concentration measurement which were taken during the freezing of the samples had been compared with the results of direct numerical modeling received by the finite difference method. The measurement of temperature fields was realized with the help of thermocouple technique. Numerical procedure was based on the full equations system of thermohaline convection. The results. The authors have shown that thermal convection, diffusion and strong positive thermodiffusion typical for the water-salt solutions can lead to the evident longitudinal division on components in the thin vertical channels filled with liquid mixtures over the selfcooling process and following freezing. The explanation of the strong longitudinal division in the liquid mixtures is based on the joint effect of two different physical mechanisms. There are thermodiffusion displacement of the admixture to the boundary layers of the channel and the large-scale axial convective flow. The similar phenomena could take place in artificial hydrological systems, natural geological processes and technological applications

On thermodiffusion influence on the dopant distribution during the freezing of binary liquid column

The relevance of the study is caused by the necessity of the extension of fundamental experimental and theoretical research in the field of macroscopic hydrodynamic phenomena in multicomponent liquid molecular mixtures. The results can be used in chemical technologies; they can change our point of view on the processes of deep waste water reclamation and safe utilization of geological resources. The main aim is to investigate the phenomenon of liquid molecular mixtures separation in thin channels by means of thermodiffusion over the self-cooling procedure; to compare different mechanisms of transfer - convection of short duration, diffusion and thermodiffusion - on the process of the components redistribution in the thin columns filled with a water-salt solution. The undertaken investigation has been executed to explain the origination of appreciable vertical stratification of different components of the mixture that gives significant variability of water salinity along the channel height. The methods used in the study: to fulfill the plan of our research the experimental and theoretical methods had been used that simulated physical processes under consideration: experimental data on concentration measurement which were taken during the freezing of the samples had been compared with the results of direct numerical modeling received by the finite difference method. The measurement of temperature fields was realized with the help of thermocouple technique. Numerical procedure was based on the full equations system of thermohaline convection. The results. The authors have shown that thermal convection, diffusion and strong positive thermodiffusion typical for the water-salt solutions can lead to the evident longitudinal division on components in the thin vertical channels filled with liquid mixtures over the selfcooling process and following freezing. The explanation of the strong longitudinal division in the liquid mixtures is based on the joint effect of two different physical mechanisms. There are thermodiffusion displacement of the admixture to the boundary layers of the channel and the large-scale axial convective flow. The similar phenomena could take place in artificial hydrological systems, natural geological processes and technological applications

Selection, Characterization, and Application of ssDNA Aptamer against Furaneol

Furaneol is an aroma compound which occurs naturally in foods and is used as an artificial flavor. Detection of furaneol is required in food science and food processing industry. Capture- Systematic Evolution of Ligands by EXponential enrichment (SELEX) protocol was applied for the isolation of an aptamer binding to furaneol, a small volatile organic substance contributing to the flavor of various products. Thirteen cycles of selection were performed. The resulting DNA pool was cloned, using blunt-end cloning, and ninety-six plasmids were sequenced and analyzed. Eight oligonucleotides were selected as aptamer candidates and screened for the ability to bind to furaneol, using three different methods—magnetic-beads associated elution assay, SYBR Green I assay, and exonuclease protection assay. One of the candidates was further characterized as an aptamer. The apparent equilibrium constant was determined to be (1.1 ± 0.4) µM, by the fluorescent method. The reported aptamer was applied for development of the ion-sensitive field-effect transistor (ISFET)-based biosensor, for the analysis of furaneol, in the concentration range of 0.1⁻10 µM

Clinical-functional and morphological parameters of purulonecrotic foci healing in diabetic foot syndrome using programmable sanitation technologies

Diabetes mellitus is currently characterised by a high progressive prevalence of patients. The purpose of this study is to evaluate the clinical, functional, and morphological parameters of purulonecrotic foci healing in diabetic foot syndrome (DFS) using programmable sanitation technologies. The patients were randomised into two groups. In the comparison group (n=51), patients received conventional local treatment after surgery. In the main group (n=55), after surgical treatment, the wound was sutured, and in the postsurgical period, programmable sanitation was conducted using the AMP-01 device. The cytological smears of the main group identified a higher rate of cellular reactions in the wound. There was a 1.3-fold reduction in the duration of hospitalisation, the number of purulent complications was significantly less (p=0.014). It was possible to preserve the supporting function of the foot in patients of the main group in a larger percentage of cases (p=0.023). There was a statistically significant increase in the frequency of high amputations in the comparison group (p=0.026). As a result, the effectiveness of the use of programmable sanitation technologies for purulent lesions of the diabetic foot has been proven