157 research outputs found

    Self-induced tunable transparency in layered superconductors

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    We predict a novel nonlinear electromagnetic phenomenon in layered superconducting slabs irradiated from one side by an electromagnetic plane wave. We show that the reflectance and transmittance of the slab can vary over a wide range, from nearly zero to one, when changing the incident wave amplitude. Thus changing the amplitude of the incident wave can induce either the total transmission or reflection of the incident wave. In addition, the dependence of the superconductor transmittance on the incident wave amplitude has an unusual hysteretic behavior with jumps. This remarkable nonlinear effect (self-induced transparency) can be observed even at small amplitudes, when the wave frequency ω\omega is close to the Josephson plasma frequency ωJ\omega_J.Comment: 9 pages, 7 figure

    Methodological Bases of Definitions “Refinancing,” “Recrediting” and Application Practice in Residential Mortgage Lending

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    A mortgage loan is considered as one of the most difficult forms of credit relations, first of all resulting in need to attract long-term financial resources on the basis of its refinancing. The expansion of foreign banks in the domestic credit markets is accompanied by a high rate of growth of credit investments into the economy of the state, and it leads to disruption of “borders” of credit and a negative impact on its development. At the same time, they are responsible for development of advanced technologies in national credit markets to improve the quality of customer service and modern banking products best suited to their needs, which include relending to borrowers. The purpose of this paper is to study the content and methodological foundations of “refinancing” and “relending” definitions, their relationships, and to identify functional orientation of these concepts in development of mortgage lending. The results of the study deepen the theoretical foundations of mortgage, the methodological tools used in practice of mortgage lending in relation to considered definitions, which allows specifying their content and developing ways of improvement. Keywords: Refinancing; liquidity; Interest rate; Relending; Financial and lending practices; Financial and credit instruments. JEL Classifications: G00; G2

    Improved Method for Preparation of 3-(1H-Indol-3-yl)benzofuran-2(3H)-ones

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    3-(1H-Indol-3-yl)benzofuran-2(3H)-ones were efficiently accessed via polyphosphoric acid-mediated condensation of 3-(2-nitrovinyl)-1H-indoles with phenols

    Проявление патогномоничных признаков при моделировании сахарного диабета стрептозотоцином у мышей BALB/c

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    Relevance. Diabetes mellitus is a widespread, socially significant disease. In this regard, it is important to obtain an experimental model that precedes subsequent experiments on pharmacological screening and/or study of the mechanism of action of antidiabetic agents.The aim of this work was a comparative assessment of the manifestation of hyperglycemia, DNA damage, and morphology of internal organs in BALB/c mice in the modeling of diabetes mellitus by a single administration of streptozotocin at a dose of 200 mg/kg and its fractional, five-day administration at a rate of 40 mg/kg per day.Methods. Streptozotocin was used as an inducer of diabetes. The drug was administered to mice once at a dose of 200 mg/kg or 5 times daily at a dose of 40 mg/kg. We monitored hyperglycemia, DNA damage in the cells of the brain, liver, kidneys, pancreas and testes, and also assessed the microscopic picture of individual internal organs, including the pancreas.Results. In both variants of the experiment, the reproduction of pathognomonic signs of diabetes mellitus is traced. They are somewhat more clearly seen in the variant of the experiment with a fractional, five-day administration of streptozotocin in single doses of 40 mg/kg.Актуальность. Сахарный диабет является широко распространённым, социально-значимым заболеванием. В связи с этим важно получить экспериментальную модель, предваряющую последующие эксперименты по фармакологическому скринингу и/или изучению механизма действия антидиабетических средств.Целью настоящей работы явилась сравнительная оценка проявления гипергликемии, повреждений ДНК и морфологии внутренних органов у мышей BALB/c при моделировании сахарного диабета однократным введением стрептозотоцина в дозе 200 мг/кг и его дробным, пятидневным введением из расчёта 40 мг/кг в сутки.Методы. В качестве индуктора диабета применяли стрептозотоцин. Препарат вводили мышам однократно в дозе 200 мг/кг или 5-кратно ежедневно в дозе 40 мг/кг. Осуществляли контроль гипергликемии, повреждённости ДНК в клетках мозга, печени, почек, поджелудочной железы и семенников, а также оценивали микроскопическую картину отдельных внутренних органов, включая поджелудочную железу.Результаты. В обоих вариантах эксперимента прослеживается воспроизведение патогномонических признаков сахарного диабета. Несколько более отчётливо они прослеживаются в варианте эксперимента с дробным, пятидневном введением стрептозотоцина в разовых дозах 40 мг/кг

    Pharmacoinformatic investigation of medicinal plants from East Africa

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    Medicinal plants have widely been used in the traditional treatment of ailments and have been proven effective. Their contribution still holds an important place in modern drug discovery due to their chemical, and biological diversities. However, the poor documentation of traditional medicine, in developing African countries for instance, can lead to the loss of knowledge related to such practices. In this study, we present the Eastern Africa Natural Products Database (EANPDB) containing the structural and bioactivity information of 1870 unique molecules isolated from about 300 source species from the Eastern African region. This represents the largest collection of natural products (NPs) from this geographical region, covering literature data of the period from 1962 to 2019. The computed physicochemical properties and toxicity profiles of each compound have been included. A comparative analysis of some physico-chemical properties like molecular weight, H-bond donor/acceptor, logP(o/w), etc. as well scaffold diversity analysis has been carried out with other published NP databases. EANPDB was combined with the previously published Northern African Natural Products Database (NANPDB), to form a merger African Natural Products Database (ANPDB), containing similar to 6500 unique molecules isolated from about 1000 source species (freely available at http://african-compounds.org). As a case study, latrunculins A and B isolated from the spongeNegombata magnifica(Podospongiidae) with previously reported antitumour activities, were identified via substructure searching as molecules to be explored as putative binders of histone deacetylases (HDACs)

    RKappa: Statistical sampling suite for Kappa models

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    We present RKappa, a framework for the development and analysis of rule-based models within a mature, statistically empowered R environment. The infrastructure allows model editing, modification, parameter sampling, simulation, statistical analysis and visualisation without leaving the R environment. We demonstrate its effectiveness through its application to Global Sensitivity Analysis, exploring it in "parallel" and "concurrent" implementations. The pipeline was designed for high performance computing platforms and aims to facilitate analysis of the behaviour of large-scale systems with limited knowledge of exact mechanisms and respectively sparse availability of parameter values, and is illustrated here with two biological examples. The package is available on github: https://github.com/lptolik/R4KappaComment: Hybrid Systems and Biology 2014, Vienn

    ASASSN-15lh: a superluminous ultraviolet rebrightening observed by Swift and Hubble

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    We present and discuss ultraviolet and optical photometry from the Ultraviolet/Optical Telescope and X-ray limits from the X-Ray Telescope on Swift and imaging polarimetry and ultraviolet/optical spectroscopy with the Hubble Space Telescope of ASASSN-15lh. It has been classified as a hydrogenpoor superluminous supernova (SLSN I) more luminous than any other supernova observed. ASASSN- 15lh is not detected in the X-rays in individual or coadded observations. From the polarimetry we determine that the explosion was only mildly asymmetric. We find the flux of ASASSN-15lh to increase strongly into the ultraviolet, with a ultraviolet luminosity a hundred times greater than the hydrogen-rich, ultraviolet-bright SLSN II SN 2008es. We find objects as bright as ASASSN-15lh are easily detectable beyond redshifts of ∼4 with the single-visit depths planned for the Large Synoptic Survey Telescope. Deep near-infrared surveys could detect such objects past a redshift of ∼20 enabling a probe of the earliest star formation. A late rebrightening – most prominent at shorter wavelengths – is seen about two months after the peak brightness, which is itself as bright as a superluminous supernova. The ultraviolet spectra during the rebrightening are dominated by the continuum without the broad absorption or emission lines seen in SLSNe or tidal disruption events and the early optical spectra of ASASSN-15lh. Our spectra show no strong hydrogen emission, showing only Lyα absorption near the redshift previously found by optical absorption lines of the presumed host. The properties of ASASSN-15lh are extreme when compared to either SLSNe or tidal disruption events

    Rational Diversification of a Promoter Providing Fine-Tuned Expression and Orthogonal Regulation for Synthetic Biology

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    Yeast is an ideal organism for the development and application of synthetic biology, yet there remain relatively few well-characterised biological parts suitable for precise engineering of this chassis. In order to address this current need, we present here a strategy that takes a single biological part, a promoter, and re-engineers it to produce a fine-graded output range promoter library and new regulated promoters desirable for orthogonal synthetic biology applications. A highly constitutive Saccharomyces cerevisiae promoter, PFY1p, was identified by bioinformatic approaches, characterised in vivo and diversified at its core sequence to create a 36-member promoter library. TetR regulation was introduced into PFY1p to create a synthetic inducible promoter (iPFY1p) that functions in an inverter device. Orthogonal and scalable regulation of synthetic promoters was then demonstrated for the first time using customisable Transcription Activator-Like Effectors (TALEs) modified and designed to act as orthogonal repressors for specific PFY1-based promoters. The ability to diversify a promoter at its core sequences and then independently target Transcription Activator-Like Orthogonal Repressors (TALORs) to virtually any of these sequences shows great promise toward the design and construction of future synthetic gene networks that encode complex “multi-wire” logic functions

    Mechanical construction and installation of the ATLAS tile calorimeter

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    This paper summarises the mechanical construction and installation of the Tile Calorimeter for the ATLAS experiment at the Large Hadron Collider in CERN, Switzerland. The Tile Calorimeter is a sampling calorimeter using scintillator as the sensitive detector and steel as the absorber and covers the central region of the ATLAS experiment up to pseudorapidities +/- 1.7. The mechanical construction of the Tile Calorimeter occurred over a period of about 10 years beginning in 1995 with the completion of the Technical Design Report and ending in 2006 with the installation of the final module in the ATLAS cavern. During this period approximately 2600 metric tons of steel were transformed into a laminated structure to form the absorber of the sampling calorimeter. Following instrumentation and testing, which is described elsewhere, the modules were installed in the ATLAS cavern with a remarkable accuracy for a structure of this size and weight

    Comparative constructions of similarity in Northern Samoyedic languages

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    The purpose of this paper is to analyze the suffixes which are used in Northern Samoyedic languages to build comparative constructions of equality. Depending on the language, the suffixes may perform three functions: word-building, form-building, and inflectional. When they mark the noun, they serve as simulative suffixes and are employed to build object comparison. In the inflectional function, these suffixes mark the verb and are a means of constructing situational comparison. In this case, they signal the formation of a special mood termed the Approximative. This paper provides a detailed description of the Approximative from paradigmatic and syntagmatic perspectives
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