Creation of a recombinant Komagataella phaffii strain, a producer of proteinase K from Tritirachium album

The objects of the study were recombinant clones of Komagataella phaffii K51 carrying the heterologous proteinase K (PK-w) gene from Tritirachium album integrated into their genome as well as samples of recombinant proteinase K isolated from these clones. The aims of this work were i) to determine whether it is possible to create recombinant K. phaffii K51 clones overexpressing functionally active proteinase K from T. album and ii) to analyze the enzymatic activity of the resulting recombinant enzyme. The following methods were used: computational analysis of primary structure of the proteinase K gene, molecular biological methods (PCR, electrophoresis of DNA in an agarose gel, electrophoresis of proteins in an SDS polyacrylamide gel under denaturing conditions, spectrophotometry, and quantitative assays of protease activity), and genetic engineering techniques (cloning and selection of genes in bacterial cells Escherichia coli TOP10 and in the methylotrophic yeast K. phaffii K51). The gene encoding natural proteinase K (PK-w) was designed and optimized for expression in K. phaffii K51. The proteinase K gene was synthesized and cloned within the plasmid pPICZα-A vector in E. coli TOP10 cells. The proteinase K gene was inserted into pPICZα-A in such a way that – at a subsequent stage of transfection into yeast cells – it was efficiently expressed under the control of the promoter and terminator of the AOX1 gene, and the product of the exogenous gene contained the signal peptide of the Saccharomyces cerevisiae a-factor to ensure the protein’s secretion into the culture medium. The resultant recombinant plasmid (pPICZα-A/PK-w) was transfected into K. phaffii K51 cells. A recombinant K. phaffii K51 clone was obtained that carried the synthetic proteinase K gene and ensured its effective expression and secretion into the culture medium. An approximate productivity of the yeast recombinant clones for recombinant proteinase K was 25 μg/ mL after 4 days of cultivation. The resulting recombinant protease has a high specific proteolytic activity: ~5000 U/mg.

Evolution of hydraulic fracturing fluid: from guar systems to synthetic gelling polymers

The paper presents the possibilities of optimizing technological approaches for performing hydraulic fracturing operations, taking into account the transition from traditionally used chemical components of the process fluid to synthetic gelling polymers. The proposed option makes it possible to reduce the unit costs of operational activities to increase oil production both for new assets of oil and gas producing companies and for assets at the stage of industrial development. The special emphasis of the proposed technological solutions is correlated with the environmental Agenda for Sustainable Development until 2030, aimed at transforming the production processes of the energy complex to reduce the ecological footprint of enterprises. A complete set of laboratory studies confirms the prospect of industrial application of synthetic polymer systems and the feasibility of replicating this approach. The subsequent stage of scale-up of pilot tests will allow to have a basis for development and implementation of standards in the oil and gas industry. Keywords: oil; well; hydraulic fracturing; chemicals; synthetic gelling polymers.

Singularity Transition in Biosystem with Infinite Number of Conserved Links with Surroundings

Stages of natural evolution such as biogenesis and abiogenesis are the well-recognized terms to characterize the very different phases of life development. Traditionally, an abiogenesis is believed as the early stage of evolution that is mainly the chemistry phase dealing with intercoupling between the complex polymer chains when manifestations of life assumes substantial participation of cooperative effects. It its turn, a biogenesis as the subsequent stage of evolution is the period for prevalence of Darwin’s laws showing, in particular, in battle among separate species in the way of variability-heredity contest. In this article, we discuss possible nature of the transition between above stages as a normal result of progress in an evolutionary system simulated by mathematical model of open system with infinite number of conserved links with system surroundings. It is shown that the biosystem, in transition point experiences the deep reconstruction in existing pattern of energy exchange which leads to emergence of the more complicated and advanced stage of evolution. Our study showed that the found transition point can be considered as a singularity point in system evolution. In its turn, the evolution stages with the dissimilar meaning are the physical placeholders for stage of abiogenesis and biogenesis in natural evolution, correspondingly.

Hemodynamic parameters in the central retinal artery in active retinopathy of prematurity and their relationship with the central retinal vein

Purpose. To analyze the main hemodynamic parameters in the central retinal artery, as well as their relationship with hemodynamic indicators in the central retinal vein, depending on the stage and type of active ROP with the use of color duplex scanning. Material and methods. The 63 premature babies with various stages of active ROP and no signs of ROP were included in the study. The 55 children with active ROP included in the study were distributed according to the stages and type of disease course. All children were at the same gestational age at the time of examination – 37–38 weeks of postmenstrual age or at 6–11 weeks of life. For all these children were performed color duplex scanning of the vessels of the eye and orbit in the modes of color Doppler mapping and pulsed Doppler. Results. The study of the hemodynamic features of the central retinal artery in premature infants with active ROP showed that the progression of the disease was accompanied by a significant increase in blood flow velocity (Vsyst and Vdiast) with each subsequent stage of ROP. A higher index of peripheral vascular resistance is recorded in comparison with the non-progressive favorable type for children with an unfavorable course of the disease.The analysis of the ratio of the maximum blood flow velocities in the central retinal artery and central retinal vein made it possible to determine in which of the vessels the hemodynamic changes are most pronounced, depending on the stage and form of active ROP. Conclusion. Thus, there are statistically significant changes in such large vessels of the retinal bed as the central retinal artery and central retinal vein during active ROP. Color duplex scanning, having a significant diagnostic potential in assessing hemodynamic parameters, made it possible to obtain reliable information about the linear blood flow velocity and the state of peripheral resistance in the central retinal artery and their relationship with the central retinal vein. This information opens up prospects for improving the accuracy of predicting the nature of the course of the disease, especially i n the early stages. Keywords: color duplex scanning, active retinopathy of prematurity, hemodynamic parameters, central retinal artery, central retinal vein

Expanding the Locus of Resistance: Understanding the Co-constitution of Control and Resistance in the Gig Economy

Existing literature examines control and resistance in the context of service organizations that rely on both managers and customers to control workers during the execution of work. Digital platform companies, however, eschew managers in favor of algorithmically mediated customer control—that is, customers rate workers, and algorithms tally and track these ratings to control workers’ future platform-based opportunities. How has this shift in the distribution of control among platforms, customers, and workers affected the relationship between control and resistance? Drawing on workers’ experiences from a comparative ethnography of two of the largest platform companies, we find that platform use of algorithmically mediated customer control has expanded the service encounter such that organizational control and workers’ resistance extend well beyond the execution of work. We find that workers have the most latitude to deploy resistance early in the labor process but must adjust their resistance tactics because their ability to resist decreases in each subsequent stage of the labor process. Our paper, thus, develops understanding of resistance by examining the relationship between control and resistance before, during, and after a task, providing insight into how control and resistance function in the gig economy. We also demonstrate the limitations of platforms’ reliance on algorithmically mediated customer control by illuminating how workers’ everyday interactions with customers can influence and manipulate algorithms in ways that platforms cannot always observe.

The scalable production of high-quality nanographite by organic radical-assisted electrochemical exfoliation.

One of the promising ways to produce graphene is the technology of graphite splitting or exfoliation, both by physical or mechanical and chemical, including electrochemical methods. The product of electro exfoliation is nanographite, which is transformed into multigraphene at the subsequent stage of liquid-phase mechanical and ultrasonic disintegration. This approach demonstrates a successful method of obtaining multigraphene from available graphite raw materials. Since, already at a potential of 1.23V, during the electrolysis of water on a graphite anode, the hydroxyl anion is discharged with the formation of a very active hydroxyl radical oxidizer, it is not surprising that when the graphite electro exfoliation process is overvolted at 10V, graphite oxidation products are formed. In order to control the defectiveness of the graphene lattice by oxidation products, we carried out processes of graphite exfoliation in the presence of both a number of reducing agents ascorbic acid, sodium borohydride, hydrazine hydrate, and in the presence of industrial antioxidants radical traps (2,2,6,6-tetramethylpiperidine-1-il)oxyl (TEMPO), (2,2,6,6-tetramethyl-4 oxo-piperidine-1-yl)oxyl (IPON), a mixture of 5,8,9-bis isomers[(2,2,6,6-tetramethyl - 4 oxo-piperidine-1-yl)]-{5,8,9-[1,1’- bi(cyclopentylidene)]-2,2’,4,4’- tetraene}(YARSIM-0215). It should be noted, that the best result of preventing the oxidation of nanographite in electro exfoliation technology in our studies is the ratio of carbon to oxygen (C/O) about 69.

JUSTIFICATION OF THE EXECUTIVITY OF THE SINGLE-FORMAT TECHNOLOGY OF AUTOMATED PROCESSING OF THE RESULTS OF GEODESIC MEASUREMENTS

The expediency of single-format technology of automated processing of geodetic measurements for the needs of the road construction industry is considered. This technology allows you to perform end-to-end automated processing of geodetic measurements with subsequent automated design and transfer the results of one design phase to the next in a single format and a single design environment. Through single-format automated technology for processing geodetic measurements and development of design solutions is to transfer the results of one stage of data processing or development of design solutions to another in one format and one software package. In the event of any corrections to previous results or the development of new solutions at any stage, all changes should be reflected in all parts of the project. This approach will allow the use of a one-time digitally developed highway project at all subsequent stages in the development of overhaul and reconstruction projects, subject to changes in the digital model of the area. The digital model of the terrain and section of the highway constructed in this way can be constantly adjusted and used at the stages of geodetic surveys, design, construction or repair and maintenance until the next geodetic surveys. End-to-end single-format cycle includes: design, technological design, engineering analysis, control programs. This ensures the integrity of the geometry in the transition to each subsequent stage. Providing end-to-end automated automated processing of geodetic measurement results for road repair or construction design tasks can be done by involving software products such as «CREDO», «Topomatic Robur», «Autodesk Civil 3D» and others. The use of single-format end-to-end automated processing of geodetic measurements with the subsequent construction of a digital terrain model will speed up and facilitate the development of design solutions, improve their quality, which in turn improves the quality of roads and man-made structures.

Thermomechanical Slip in Elastic Contact Between Identical Materials

The contact problem for interaction between an elastic sphere and an elastic half-space is considered taking into account partial thermomechanical frictional slip induced by thermal expansion of the half-space. The elastic constants of the bodies are assumed to be identical. The Amontons–Coulomb law is used to account for friction. The problem is reduced to non-linear boundary integral equations that correspond to the initial stage of mechanical loading and the subsequent stage of thermal loading. The dependences of the contact stress distribution, relative displacements of the contacting surfaces, dimensions of the stick and slip zones on temperature of the half-space are studied numerically. It was revealed that an increase in temperature causes increases in the shear contact stress and the relative shear displacements of the contacting surfaces. The absolute values of the shear contact stress reach their maximum at the boundaries of the stick zones. The greatest value of the moduli of the relative shear displacements are reached at the boundary of the contact region. The stick zone radius decreases monotonically according to a nonlinear law with increasing temperature.

Qualimetric methods of diagnostics of an individual's readiness for further training

В статье представлены критерии когнитивной готовности индивида к дальнейшему обучению. Известно, что в России сложилась система непрерывного образования, и обеспечение преемственности между ступенями – одна из ключевых задач. Также известно, что в современном мире популярна концепция «образования через всю жизнь». Но очевидно, что для конкретного индивида реализация данной концепции возможна лишь в том случае, если он готов к обучению на дальнейшем этапе (последующей ступени). Недостаточная разработанность моделей и методов диагностики готовности индивида к дальнейшему обучению препятствует совершенствованию системы непрерывного образования, обеспечению преемственности между его ступенями. При выделении критериев когнитивной готовности авторы учитывали, что компетенции и личностно-профессиональные качества включают в себя не только соответствующие знания и умения, но также личный опыт соответствующей деятельности. Теоретическая значимость результатов настоящего исследования в том, что они могут быть базой для дальнейшего научного осмысления проблемы становления конкурентоспособной личности в системе непрерывного образования, практическая значимость – в том, что они могут быть использованы в системах психолого-педагогического мониторинга (мониторинга личностно-профессионального развития). Методы исследования: анализ научной литературы и передового педагогического опыта, моделирование, методы квалиметрии, метод экспертных оценок, методы математической статистики, методы теории множеств, методы линейной алгебры, методы инфометрии. Методологические основы исследования: системный, социологический, компетентностный, личностно-ориентированный, деятельностный, квалиметрический и вероятностно-статистический подходы. The article presents the criteria of an individual's cognitive readiness for further education. It is known that Russia has a system of continuing education, and ensuring continuity between the stages is one of the key tasks. It is also known that the concept of “lifelong learning" is popular in the modern world. But it is obvious that for a particular individual, the implementation of this concept is possible only if he is ready to learn at a further stage (subsequent stage). Insufficient development of models and methods for the diagnosis of an individual's readiness for further education hinders the improvement of the system of continuing education, ensuring continuity between its stages. When identifying the criteria of cognitive readiness, the authors took into account that competencies and personal and professional qualities include not only relevant knowledge and skills, but also personal experience of the relevant activity. The theoretical significance of the results of this study is that they can be the basis for further scientific understanding of the problem of becoming a competitive personality in the system of continuing education, the practical significance is that they can be used in systems of psychological and pedagogical monitoring (monitoring of personal and professional development). Research methods: analysis of scientific literature and advanced pedagogical experience, modeling, methods of quantification, method of expert assessments, methods of mathematical statistics, methods of set theory, methods of linear algebra, methods of info-metric. Methodological foundations of the research: systematic, sociological, competence-based, personality-oriented, activity-based, qualimetric and probabilistic-statistical approaches.

Finite element analysis in the modeling of the heart and aorta structures

Rationale: 3D modeling of various anatomical structures has recently become a separate area of topographical, anatomical, and biomechanical studies. Current in vivo visualization methods and quantitative analysis in silico allow to perform the precise modeling of these processes aimed at investigation into the pathophysiology of cardiovascular disorders, risk prediction, planning of surgical interventions and virtual refinement of their separate stages.Aim: To develop tools for elaboration, analysis and validation of personalized models of various structures of the heart and aortal arch taking into account their morphological characteristics.Materials and methods: We used the results of 14 computed tomography studies from randomized patients without any disease or anomaly of the heart, aortic valve and aortal bulb. The analysis and subsequent transformation of the images were done with Vidar DICOM Viewer, SolidWorks 2016, VMTKLab software. For the FSI modeling of the aortic arch based on the results of functional multiaxial computed (MAC) coronarography (a female patient of 55 years) we developed a personalized model of the ascending aorta and aortic arch at the beginning of the systole. Using HyperMesh software (Altair Engineering Inc., USA) we have built a network of finite element of the luminal area, adventitia, and aortic media. To model mechanical properties of the aortic structures we used an anisotropic hyperelastic material model by Holzapfel – Gasser – Ogden. Material modeling, choice of the limiting antecedents, and analysis of fluid-structure interaction were performed with Abaqus CAE 6.14 software (Simulia, Johnston, USA). Adaptive image meshing by Young was used to elaborate the finite element template of the left ventricle. The algorithm was realized within the IDE PyCharm software media in Python 3.7. The algorithm was realized based on the open-source libraries OpenCV, NumPy, Matplotlib, and SciPy.Results: The first stage of the development of the aortic valve model included the design of its virtual 3D template. Thereafter, a cohesive geometric model was elaborated. Subsequent stage of the work included the transformation of the aortic valve geometric model into the parametric one. This was done through the use of the “Equations” tool within the SolidWorks. No problems with geometry of the model during its deformation were identified. Aortic segment modeling was based on the data obtained by functional MAC coronarography. Based on this and on Inobitec Dicom Viewer software, we generated a multiplane reconstruction of the zone of interest including anatomical structure of the heart and aortic valve. With the resulting set of contours, we created a 3D model, which then was converted into a polygonal stereolithographic model. We developed an algorithm for adaptive meshing to elaborate a polygonal template capable of deformation that can be used for registration both with the net methods (B-Spline) and based on the image characteristics (homologous pixels). Conclusion: The resulting parametric 3D model of the aortic valve anatomical structures is capable of adequate transformation of its geometry under external factors. It can be used in simulators of endovascular cardiosurgical procedures.