814 research outputs found

    Using the mineral component of building refuse in heavy metals sorption from their mixture

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    The sorption properties of the sand-breakstone mixture based on the mineral component of building refuse of the 0-10 mm fraction with respect to Pb2+, Zn2+, Cu2+, Ni2+, Cd2+ and Hg2+ ions were studied using atomic absorption spectroscopy. The mechanisms of accumulation of heavy metal ions on the surface of the mixture particles are described. It was found that after washing the contaminated material distilled water, the residual concentration of metals in the filtrate does not exceed the established sanitary and hygienic standards. The practical value of the work lies in the possibility of applying the results in reclamation of technogenic formations or production of materials for the technical stage of reclamation using technogenic soils

    Clinical and anatomical traits of orthopaedic traumatic and maxillofacial osteomyelitis: a systematic review

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    Background. Chronic osteomyelitis requires a multidisciplinary approach. The main contributors are physicians of two specialties, orthopaedic trauma and maxillofacial surgeons, depending on the pathology’s localisation. Each specialty often relies on its own research and experience, whereas a cross-disciplinary assessment of same pathology allows a broader perspective of the problem.Objectives. A comparative survey of orthopaedic trauma and maxillofacial evidence on the aetiology, pathogenesis and treatment of osteomyelitis for effective sharing and leveraging of practices.Methods. The review generalizes relevant publications on the etiopathogenesis and treatment of osteomyelitis of various location in different patient profiles indexed in the PubMed, Science-Direct and eLIBRARY databases from January 2014 till June 2020. The keyword queries were: osteomyelitis jaws [остеомиелит челюстей], osteomyelitis mandible maxilla, osteomyelitis lower limb [остеомиелит нижних конечностей], osteomyelitis microbiology antibiotic therapy [остеомиелит микрофлора]. We conducted historical and bibliometric analyses of domestic and foreign scientific archives on general and special issues in anatomy, aetiology, pathogenesis and treatment of chronic osteomyelitis of various location.Results. The working ability and social adaptation are recovered in chronic osteomyelitis patients via a multicomponent process, which includes conservative therapy, surgical treatment and rehabilitation measures.Conclusion. Main aetiological and pathogenetic traits of chronic osteomyelitis of various location can be used to lay out interdisciplinary tactics in purulent necrotic surgery utilising various materials and methods for function restore

    Broadband spectroscopy of astrophysical ice analogues: II. Optical constants of CO and CO2_2 ices in the terahertz and infrared ranges

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    Context: Broadband optical constants of astrophysical ice analogues in the infrared (IR) and terahertz (THz) ranges are required for modeling the dust continuum emission and radiative transfer in dense and cold regions, where thick icy mantles are formed on the surface of dust grains. Aims: In this paper, the THz time-domain spectroscopy (TDS) and the Fourier-transform IR spectroscopy (FTIR) are combined to study optical constants of CO and CO2_2 ices in the broad THz-IR spectral range. Methods: The measured ices are grown at cryogenic temperatures by gas deposition on a cold Si window. A method to quantify the broadband THz-IR optical constants of ices is developed based on the direct reconstruction of the complex refractive index of ices in the THz range from the TDS data, and the use of the Kramers-Kronig relation in the IR range for the reconstruction from the FTIR data. Uncertainties of the Kramers-Kronig relation are eliminated by merging the THz and IR spectra. The reconstructed THz-IR response is then analyzed using classical models of complex dielectric permittivity. Results: The complex refractive index of CO and CO2_2 ices deposited at the temperature of 2828 K is obtained in the range of 0.3--12.0 THz. Based on the measured dielectric constants, opacities of the astrophysical dust with CO and CO2_2 icy mantles are computed. Conclusions: The developed method can be used for a model-independent reconstruction of optical constants of various astrophysical ice analogs in a broad THz-IR range. Such data can provide important benchmarks to interpret the broadband observations from the existing and future ground-based facilities and space telescopes. The reported results will be useful to model sources that show a drastic molecular freeze-out, such as central regions of prestellar cores and mid-planes of protoplanetary disks, as well as CO and CO2_2 snow lines in disks.Comment: Accepted for publication in A&A, 9 pages, 7 figure

    A Discrete Version of the Inverse Scattering Problem and the J-matrix Method

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    The problem of the Hamiltonian matrix in the oscillator and Laguerre basis construction from the S-matrix is treated in the context of the algebraic analogue of the Marchenko method.Comment: 11 pages. The Laguerre basis case is adde

    Inverse scattering J-matrix approach to nucleon-nucleus scattering and the shell model

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    The JJ-matrix inverse scattering approach can be used as an alternative to a conventional RR-matrix in analyzing scattering phase shifts and extracting resonance energies and widths from experimental data. A great advantage of the JJ-matrix is that it provides eigenstates directly related to the ones obtained in the shell model in a given model space and with a given value of the oscillator spacing Ω\hbar\Omega. This relationship is of a particular interest in the cases when a many-body system does not have a resonant state or the resonance is broad and its energy can differ significantly from the shell model eigenstate. We discuss the JJ-matrix inverse scattering technique, extend it for the case of charged colliding particles and apply it to the analysis of nαn\alpha and pαp\alpha scattering. The results are compared with the No-core Shell Model calculations of 5^5He and 5^5Li.Comment: Some text is added following suggestions of a journal refere

    OBTAINING CHIMERIC VARIANTS HBcAg EXPOSING HIV-1 MPER FRAGMENTS

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    The HIV-1 epidemic is one of the most acute global health problems. For several reasons, an effective vaccine against this infection has not yet been created. Currently, an important direction in the development of a vaccine against HIV / AID S is the design of immunogens that would be able to induce antibodies that neutralize a high diversity of HIV-1 strains (bNAbs). One approach to creating such immunogens is the construction of chimeric virus-like particles (VLPs) exposing epitopes recognized by bNAbs. The aim of the study was to obtain and characterize chimeric VLPs based on HBcAg, exposing epitopes recognized by bNAbs 2F5 and 4E10. Material and methods. The producing strains of  chimeric HBcAg variants were obtained by transforming E. coli BL21 cells with recombinant plasmids carrying the HBcAg genes and containing insertions encoding bNAbs epitopes 2F5 and 4E10. Purification of recombinant proteins was performed using gel filtration on a sepharose CL-6B column. The ability of recombinant HBcAg to form virus-like particles was assessed using electron microscopy. Analysis of the antigenic properties of epitopes in the composition of chimeric variants of HBcAg was performed using immunoblotting. Results. A modified nucleotide sequence of the HBcAg gene was obtained, which included the introduction of unique restriction sites flanking the region of the main antigenic determinant of the core. Based on this genetic construct, three recombinant plasmids encoding chimeric HBcAg variants, including epitopes of bNAbs 2F5 and 4E10, were obtained. Using immunoblotting, it was found that epitopes recognized by bNAbs retain their antigenic properties after insertion into the HBcAg

    Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

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    The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal
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