Carbon nanotube array as a van der Waals two-dimensional hyperbolic material

We use an ab-initio approach to design and study a novel two-dimensional material - a planar array of carbon nanotubes separated by an optimal distance defined by the van der Waals interaction. We show that the energy spectrum for an array of quasi-metallic nanotubes is described by a strongly anisotropic hyperbolic dispersion and formulate a model low-energy Hamiltonian for its semi-analytical treatment. Periodic-potential-induced lifting of the valley degeneracy for an array of zigzag narrow-gap nanotubes leads to the band gap collapse. In contrast, the band gap is opened in an array of gapless armchair tubes. These unusual spectra, marked by pronounced van Hove singularities in the low-energy density of states, open the opportunity for interesting physical effects and prospective optoelectronic applications

Development of a Mathematical Model of Business Process to Optimize the Budget Department’s Work in Machine-building Enterprises

The article covers the highlights in the development of an optimal mathematical model of business process of the budget department’s work in machine-building enterprises. There has been done the analysis of basic problems in the engineering field, arising in the course of economic instability and deterioration of the businessstrategy. The investigation discussed is aimed to improve the competitiveness in the market and optimize the strategy of the organization’s activities as a whole. Special attention is paid to the methods of mathematical modeling of business process on the basis of queuing theory to develop the authoring mathematical model. The developed model would make it possible to evaluate and optimize the performance of the budgetdepartments of engineering enterprises

The effect of hydrogenation on the fracture of Ti₂AlNb-based alloy during ball milling

In this work we have studied the effect of phase composition and microstructure of a rapidly solidified Ti₂AlNb-based alloy containing hydrogen on deformation of the alloy during ball milling and production of a fine-dispersed powder. Hydrogen is introduced into the alloy up to a concentration of 2.0 wt

Compositional variation of thin PZT films near morphotropic phase boundary: experiment and simulation

The work was partly supported by the Ministry for Education and Science (Russian Federation) (Grant No 16.2811.2017/4.6) and RFBR (Grant No 16-02-00632)

Drosophila S2 Cells Are Non-Permissive for Vaccinia Virus DNA Replication Following Entry via Low pH-Dependent Endocytosis and Early Transcription

Vaccinia virus (VACV), a member of the chordopox subfamily of the Poxviridae, abortively infects insect cells. We have investigated VACV infection of Drosophila S2 cells, which are useful for protein expression and genome-wide RNAi screening. Biochemical and electron microscopic analyses indicated that VACV entry into Drosophila S2 cells depended on the VACV multiprotein entry-fusion complex but appeared to occur exclusively by a low pH-dependent endocytic mechanism, in contrast to both neutral and low pH entry pathways used in mammalian cells. Deep RNA sequencing revealed that the entire VACV early transcriptome, comprising 118 open reading frames, was robustly expressed but neither intermediate nor late mRNAs were made. Nor was viral late protein synthesis or inhibition of host protein synthesis detected by pulse-labeling with radioactive amino acids. Some reduction in viral early proteins was noted by Western blotting. Nevertheless, synthesis of the multitude of early proteins needed for intermediate gene expression was demonstrated by transfection of a plasmid containing a reporter gene regulated by an intermediate promoter. In addition, expression of a reporter gene with a late promoter was achieved by cotransfection of intermediate genes encoding the late transcription factors. The requirement for transfection of DNA templates for intermediate and late gene expression indicated a defect in viral genome replication in VACV-infected S2 cells, which was confirmed by direct analysis. Furthermore, VACV-infected S2 cells did not support the replication of a transfected plasmid, which occurs in mammalian cells and is dependent on all known viral replication proteins, indicating a primary restriction of DNA synthesis

Experimental Investigations of Changes in beta-decay rate of Co-60 and Cs-137

Results of simultaneous measurements of beta-decay rate with the aid of Ge(Li)-detectors performed at two laboratories 140km apart (INR RAS, Troitsk, Co-60, and JINR, Dubna, Cs-137) during a period from 15.03.2000 till 10.04.2000, are presented. Regular deviations of the count rate of gamma-quanta following the beta-decay of $\sim$ 0.7% (INR RAS, Co-60) and $\sim$ 0.2% (JINR, Cs-137) from the statistical average, are observed. The analysis of extremum deviations of gamma-quanta count rate shows that the set of directions of tangents to the Earth's parallels of latitude at the extremum points of trajectories of motion in the space of each laboratory clearly forms three separate compact subsets of directions which agree, for two laboratories, to an accuracy of $\pm10^\circ$. This phenomenon is shown not to be explained on the basis of traditional notion. A possible explanation is suggested basing on the hypothesis that there exists a new anisotropic interaction caused by the cosmological vectorial potential \textbf{A}$_{\rm g}$, a new fundamental constant having, according to the experiments carried out, the coordinate of right ascension $\alpha \approx 285^\circ$ in the second equatorial system. This is in agreement with earlier experiments.Comment: 13 pages, LaTeX2e, 4 PS figure

The Membrane Fusion Step of Vaccinia Virus Entry Is Cooperatively Mediated by Multiple Viral Proteins and Host Cell Components

For many viruses, one or two proteins allow cell attachment and entry, which occurs through the plasma membrane or following endocytosis at low pH. In contrast, vaccinia virus (VACV) enters cells by both neutral and low pH routes; four proteins mediate cell attachment and twelve that are associated in a membrane complex and conserved in all poxviruses are dedicated to entry. The aim of the present study was to determine the roles of cellular and viral proteins in initial stages of entry, specifically fusion of the membranes of the mature virion and cell. For analysis of the role of cellular components, we used well characterized inhibitors and measured binding of a recombinant VACV virion containing Gaussia luciferase fused to a core protein; viral and cellular membrane lipid mixing with a self-quenching fluorescent probe in the virion membrane; and core entry with a recombinant VACV expressing firefly luciferase and electron microscopy. We determined that inhibitors of tyrosine protein kinases, dynamin GTPase and actin dynamics had little effect on binding of virions to cells but impaired membrane fusion, whereas partial cholesterol depletion and inhibitors of endosomal acidification and membrane blebbing had a severe effect at the later stage of core entry. To determine the role of viral proteins, virions lacking individual membrane components were purified from cells infected with members of a panel of ten conditional-lethal inducible mutants. Each of the entry protein-deficient virions had severely reduced infectivity and except for A28, L1 and L5 greatly impaired membrane fusion. In addition, a potent neutralizing L1 monoclonal antibody blocked entry at a post-membrane lipid-mixing step. Taken together, these results suggested a 2-step entry model and implicated an unprecedented number of viral proteins and cellular components involved in signaling and actin rearrangement for initiation of virus-cell membrane fusion during poxvirus entry

Multiple Phosphatidylinositol 3-Kinases Regulate Vaccinia Virus Morphogenesis

Poxvirus morphogenesis is a complex process that involves the successive wrapping of the virus in host cell membranes. We screened by plaque assay a focused library of kinase inhibitors for those that caused a reduction in viral growth and identified several compounds that selectively inhibit phosphatidylinositol 3-kinase (PI3K). Previous studies demonstrated that PI3Ks mediate poxviral entry. Using growth curves and electron microscopy in conjunction with inhibitors, we show that that PI3Ks additionally regulate morphogenesis at two distinct steps: immature to mature virion (IMV) transition, and IMV envelopment to form intracellular enveloped virions (IEV). Cells derived from animals lacking the p85 regulatory subunit of Type I PI3Ks (p85α−/−β−/−) presented phenotypes similar to those observed with PI3K inhibitors. In addition, VV appear to redundantly use PI3Ks, as PI3K inhibitors further reduce plaque size and number in p85α−/−β−/− cells. Together, these data provide evidence for a novel regulatory mechanism for virion morphogenesis involving phosphatidylinositol dynamics and may represent a new therapeutic target to contain poxviruses

Широкозахватный опрыскиватель с гибким отводом и летательными аппаратами для обработки посевов риса

The article presents the brief analysis of existing technical determinations for spraying, the surface injection of liquid solutions, in the course of which about 75 percent of pesticides used in agricultural production are injected in order to preserve the crop from pests, diseases and weeds. (Purpose of the study) To develop the wide-coverage sprinkler with extended operational and technological capabilities for the rice sowings. (Materials and methods) It has been established that the main criterion for the up-to-date creation of the technical equipment used for spraying is the reduction of norms of the working fluid consumption and the level of environmental pollution by pesticides and also that the domesticmachines for this use coming to the market have low technical performance indicators and insufficient reliability. (Results and discussions) The design of a new wide-coverage spraying machine with a flexible tap and vehicles for the spraying of rice and with extended operational and technological capabilities, containing two propulsion units (one with a current generator, the other with a solution tank and a pressure pipeline) has been suggested. They are equipped with the frames with tensioners and are kinematically connected to each other by a flexible carcase on which the vehicles and suspended nodes of the mud channel with spraying machines are placed. The spraying of the rice fields by vehicles confirms theexpediency of their application in the rice industry for the ensuring of significant reduction in the crop losses from plant diseases. The production of new chemicals with low consumption rates and enhanced biological activity served as the basis for the development of the proposed design of wide-coverage sprinkler to meet modern requirements for sprayers of this type and intended for the use in medium and large rice farms. (Conclusions) The use of the presented wide-coverage sprinkler will allow farmers to apply intensive technology of rice cultivation on rice farms, and it will significantly increase the effectiveness of protective measures and reduce the consumption rates of chemicals, as well as reduce haul costs and spraying of working liquid solutions. The adoption of new technologies and technical means of plant protection that meetmodern requirements are worthy of continued work on their improvement and, in particular, the creation of new technicalmeans of weed controlПриведен краткий анализ существующих технических решений для поверхностного внесения жидких растворов – опрыскивания, в процессе которого вносится до 75 процентов применяемых в сельскохозяйственном производстве ядохимикатов с целью сохранения урожая от вредителей, болезней и сорной растительности. (Цель исследований) Разработать широкозахватный опрыскиватель для посевов риса с расширенными эксплуатацион-но-технологическими возможностями. (Материалы и методы) Отметили, что основным критерием, отвечающим современным требованиям по созданию технических средств для опрыскивания, служит снижение норм расхода рабочей жидкости и уровня загрязнения окружающей среды ядохимикатами. Показали, что поступающие на рынок отечественные машины данного назначения имеют низкие технико-эксплуатационные показатели и недостаточную надежность. (Результат и обсуждение) Предложили конструкцию нового широкозахватного опрыскивателя для риса с расширенными эксплуатационно-технологическими возможностями, с гибким отводом и летательными аппаратами. В конструкцию включены два движителя (один с генератором тока, другой – с емкостью дляраствора и напорным трубопроводом). Они оснащены рамами с натяжителями и кинематически связаны между собой гибким остовом, на котором размещены летательные аппараты и подвесные узлы растворопровода с распылителями. Подтвердили целесообразность обработки рисовых полей летательными аппаратами для обеспечениясущественного сокращения потерь урожая от заболеваний растений. Предложили конструкцию широкозахватного опрыскивателя, отвечающего современным требованиям к опрыскивателям данного вида и предназначенного для применения в средних и крупных рисоводческих хозяйствах при использовании новых химических веществ с небольшими нормами расхода и усиленной биологической активностью. (Выводы) Провели теоретические расчеты, позволяющие обосновать конструктивно-технологические параметры разрабатываемого широкозахватного опрыскивателя, учитывающие основные факторы, оказывающие влияние на качество процесса опрыскивания. Показали, что использование представленного широкозахватного опрыскивателя позволит в рисоводческих хозяйствах применить интенсивную технологию возделывания риса, что существенно повысит эффективность защитных мероприятий и сократит нормы расхода химикатов, а также снизит затраты на транспортировку и внесение жидких рабочих растворо

Investigation of the unipolar and polarized thin PZT films under variation of lead excess

Целью данной работы является исследование методом атомно-силовой микроскопии естественно униполярных и поляризованных в сильном электрическом поле тонких пленок Pb(Zr,Ti)O3 при варьировании сверх стехиометрического содержания свинца в твердых растворах.The aim of the work is to study the self-poled and polarized thin Pb(Zr,Ti)O3 films under variation of over stoichiometric content lead using piezoelectric force microscopy