97 research outputs found

    Synthesis of stable sols based on titanium dioxide, silicon and metal ion for use in photocatalysis

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    The paper presents the study of physicochemical processes occurring during the preparation of film-forming solutions, as well as the effect of the component composition on the stability of film-forming solutions over time. Compositions of stable film-forming solutions of TBT, TBT-TEOS, TBT-TEOS-AgNO3 suitable for the formation of thin-film coatings have been developed, and the time periods of stability of rheological properties have been determined. It was found that the addition of tetrabutoxytitanium after the establishment of chemical equilibrium in the solution increases the stability of the film-forming solutions. Optimization of the method of solutions preparation for obtaining films with reproducible physicochemical properties has been carried out

    Prediction of Anisotropic Single-Dirac-Cones in Bi1x{}_{1-x}Sbx{}_{x} Thin Films

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    The electronic band structures of Bi1x{}_{1-x}Sbx{}_{x} thin films can be varied as a function of temperature, pressure, stoichiometry, film thickness and growth orientation. We here show how different anisotropic single-Dirac-cones can be constructed in a Bi1x{}_{1-x}Sbx{}_{x} thin film for different applications or research purposes. For predicting anisotropic single-Dirac-cones, we have developed an iterative-two-dimensional-two-band model to get a consistent inverse-effective-mass-tensor and band-gap, which can be used in a general two-dimensional system that has a non-parabolic dispersion relation as in a Bi1x{}_{1-x}Sbx{}_{x} thin film system

    Transverse-momentum-dependent Multiplicities of Charged Hadrons in Muon-Deuteron Deep Inelastic Scattering

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    A semi-inclusive measurement of charged hadron multiplicities in deep inelastic muon scattering off an isoscalar target was performed using data collected by the COMPASS Collaboration at CERN. The following kinematic domain is covered by the data: photon virtuality Q2>1Q^{2}>1 (GeV/cc)2^2, invariant mass of the hadronic system W>5W > 5 GeV/c2c^2, Bjorken scaling variable in the range 0.003<x<0.40.003 < x < 0.4, fraction of the virtual photon energy carried by the hadron in the range 0.2<z<0.80.2 < z < 0.8, square of the hadron transverse momentum with respect to the virtual photon direction in the range 0.02 (GeV/c)2<PhT2<3c)^2 < P_{\rm{hT}}^{2} < 3 (GeV/cc)2^2. The multiplicities are presented as a function of PhT2P_{\rm{hT}}^{2} in three-dimensional bins of xx, Q2Q^2, zz and compared to previous semi-inclusive measurements. We explore the small-PhT2P_{\rm{hT}}^{2} region, i.e. PhT2<1P_{\rm{hT}}^{2} < 1 (GeV/cc)2^2, where hadron transverse momenta are expected to arise from non-perturbative effects, and also the domain of larger PhT2P_{\rm{hT}}^{2}, where contributions from higher-order perturbative QCD are expected to dominate. The multiplicities are fitted using a single-exponential function at small PhT2P_{\rm{hT}}^{2} to study the dependence of the average transverse momentum PhT2\langle P_{\rm{hT}}^{2}\rangle on xx, Q2Q^2 and zz. The power-law behaviour of the multiplicities at large PhT2P_{\rm{hT}}^{2} is investigated using various functional forms. The fits describe the data reasonably well over the full measured range.Comment: 28 pages, 20 figure

    Инвазивный микоз с поражением центральной нервной системы, обусловленный редкими дрожжевыми грибами Malassezia spp., у пациентов с острым лейкозом: описание клинических случаев и обзор литературы

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    Malassezia spp. is a commensal yeast that represents normal microflora in humans and some animals. However, Malassezia spp. can cause life-threatening invasive mycosis. Evidence on Malassezia spp. infections is limited mostly to a case reports describing disease in newborns and premature infants, because lipid infusions (total parenteral nutrition) given through central venous catheter is a major risk factor. Here, we report two cases of CNS infection caused by Malassezia species in non-neonates with acute leukemia.Malassezia spp. — дрожжевые грибы, которые представлены в составе нормальной микрофлоры кожи человека и как симбионт препятствуют развитию инфекций, обусловленных опасными патогенами. Однако Malassezia spp. также может стать причиной тяжелого инвазивного микоза и привести к летальному исходу. Данные литературы ограничены, представлены преимущественно публикациями об инфекциях у новорожденных и недоношенных детей, что, в первую очередь, связывают с известным фактором риска — применение парентерального питания, включающего в себя жировую эмульсию, с использованием центрального венозного катетера. Мы представляем клинические случаи инфекции центральной нервной системы, обусловленной редкими возбудителями, дрожжевыми грибами рода Malassezia, у детей с острым лейкозом

    Using Shifts in Amino Acid Frequency and Substitution Rate to Identify Latent Structural Characters in Base-Excision Repair Enzymes

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    Protein evolution includes the birth and death of structural motifs. For example, a zinc finger or a salt bridge may be present in some, but not all, members of a protein family. We propose that such transitions are manifest in sequence phylogenies as concerted shifts in substitution rates of amino acids that are neighbors in a representative structure. First, we identified rate shifts in a quartet from the Fpg/Nei family of base excision repair enzymes using a method developed by Xun Gu and coworkers. We found the shifts to be spatially correlated, more precisely, associated with a flexible loop involved in bacterial Fpg substrate specificity. Consistent with our result, sequences and structures provide convincing evidence that this loop plays a very different role in other family members. Second, then, we developed a method for identifying latent protein structural characters (LSC) given a set of homologous sequences based on Gu's method and proximity in a high-resolution structure. Third, we identified LSC and assigned states of LSC to clades within the Fpg/Nei family of base excision repair enzymes. We describe seven LSC; an accompanying Proteopedia page (http://proteopedia.org/wiki/index.php/Fpg_Nei_Protein_Family) describes these in greater detail and facilitates 3D viewing. The LSC we found provided a surprisingly complete picture of the interaction of the protein with the DNA capturing familiar examples, such as a Zn finger, as well as more subtle interactions. Their preponderance is consistent with an important role as phylogenetic characters. Phylogenetic inference based on LSC provided convincing evidence of independent losses of Zn fingers. Structural motifs may serve as important phylogenetic characters and modeling transitions involving structural motifs may provide a much deeper understanding of protein evolution

    Corrigendum to "Transverse extension of partons in the proton probed in the sea-quark range by measuring the DVCS cross section" [Phys. Lett. B 793 (2019) 188]

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    Light isovector resonances in π-p →π-π-π+p at 190 GeV/c

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    We have performed the most comprehensive resonance-model fit of π-π-π+ states using the results of our previously published partial-wave analysis (PWA) of a large data set of diffractive-dissociation events from the reaction π-+p→π-π-π++precoil with a 190 GeV/c pion beam. The PWA results, which were obtained in 100 bins of three-pion mass, 0.5<2.5 GeV/c2, and simultaneously in 11 bins of the reduced four-momentum transfer squared, 0.1<1.0 (GeV/c)2, are subjected to a resonance-model fit using Breit-Wigner amplitudes to simultaneously describe a subset of 14 selected waves using 11 isovector light-meson states with JPC=0-+, 1++, 2++, 2-+, 4++, and spin-exotic 1-+ quantum numbers. The model contains the well-known resonances π(1800), a1(1260), a2(1320), π2(1670), π2(1880), and a4(2040). In addition, it includes the disputed π1(1600), the excited states a1(1640), a2(1700), and π2(2005), as well as the resonancelike a1(1420). We measure the resonance parameters mass and width of these objects by combining the information from the PWA results obtained in the 11 t′ bins. We extract the relative branching fractions of the ρ(770)π and f2(1270)π decays of a2(1320) and a4(2040), where the former one is measured for the first time. In a novel approach, we extract the t′ dependence of the intensity of the resonances and of their phases. The t′ dependence of the intensities of most resonances differs distinctly from the t′ dependence of the nonresonant components. For the first time, we determine the t′ dependence of the phases of the production amplitudes and confirm that the production mechanism of the Pomeron exchange is common to all resonances. We have performed extensive systematic studies on the model dependence and correlations of the measured physical parameters

    Инвазивный аспергиллез, обусловленный Aspergillus non-fumigatus, у взрослых пациентов после аллогенной трансплантации гемопоэтических стволовых клеток

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       Objective. To study the features of invasive aspergillosis (IA) due to A. non-fumigatus versus A. fumigatus in adult (≥ 18 years) recipients of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in 2016-2021.   Materials and methods. The study included 33 patients with IA caused by A. non-fumigatus (n = 20) and A. fumigatus (n = 13). A comparative analysis of cases of IA, the results of therapy and outcomes in patients after allo-HSCT in the RM Gorbacheva Research Institute was performed. Diagnostic criteria EORTC / MSGERC 2020 were used.   Results. Invasive aspergillosis caused by A. non-fumigatus made up the majority (60.6 %) of IA cases with an identified pathogen registered in patients after allo-HSCT in the period from 2016 to 2021. The main etiological agents in the A. non-fumigatus group were A. niger in 13 (65 %) patients, A. flavus – in 4 (20 %). The median day of diagnosis of A. non-fumigatus IAwas + 110 days (17–2093), for A. fumigatus it was + 46 days (2–866) (p = 0.171). Overall 12-week survival was 55 % and 59.2 % in the A. non-fumigatus and A. fumigatus groups, respectively (p = 0.617). The majority of patients in both the A. fumigatus (n = 10, 77 %) and A. non-fumigatus (n = 16, 80 %) groups received voriconazole as initial antifungal therapy. Second-linetherapy was required in 2 (10 %) patients with A. non-fumigatus IA: liposomal amphotericin B and echinocandins with or with-out posaconazole, and 2 (15 %) patients in the A. fumigatus group: liposomal amphotericin B and voriconazole in combination with echinocandins. A comparative analysis showed that in patients from the two groups, none of the assessed signs (gender, age, underlying disease, disease status at the time of transplantation, time from diagnosis to allo-HSCT, source of hematopoietic stem cells, conditioning regimen, donor type, antifungal prophylaxis, cytomegalovirus reactivation, severe acute and chronic graft-versus-host disease) did not differ significantly.   Conclusions. A. niger is the main causative agent of IA caused by A. non-fumigatus. Patients characteristics, their treatment and outcomes did not differ significantly between the A. non-fumigatus and A. fumigatus groups.   Цель: изучить особенности инвазивного аспергиллеза, обусловленного A. не-fumigatus в сравнении с A. fumigatus, у взрослых (≥ 18 лет) реципиентов аллогенной трансплантации гемопоэтических стволовыхклеток в 2016–2021 гг.   Материалы и методы. В исследование включили 33 пациента с инвазивным аспергиллезом, обусловленным A. не-fumigatus (n=20) и A. fumigatus (n=13), после аллогенной трасплантации гемопоэтических клеток, выполненной в клинике Научно-исследовательского института детской онкологии, гематологии и трансплантологии им. Р. М. Горбачевой. Использовали диагностические критерии EORTC / MSGERC, 2020.   Результаты. Обусловленный A. не-fumigatus инвазивный аспергиллез составил большую часть (60,6 %) случаев инвазивного аспергиллеза с идентифицированным возбудителем у пациентов после алло-трансплантации гемопоэтических стволовых клеток в 2016–2021 гг. В группе A. не-fumigatus основными возбудителями были A. niger (13, 65 %) и A. flavus (4, 20 %). Сравнительный анализ показал, что в группах сравнения ни один из оцениваемых признаков (пол, возраст, диагноз, статус заболевания на момент трансплантации, время от постановки диагноза до аллотрансплантации гемопоэтических стволовых клеток, источник гемопоэтических стволовых клеток, режим кондиционирования, тип донора, противогрибковая профилактика, реактивация цитомегаловируса, тяжелая острая и хроническая реакция трансплантат против хозяина) достоверно не различались. Медиана срока постановки диагноза A. не-fumigatus инвазивного аспергиллеза составила 110 дней (17 – 2093) после алло-трансплантации гемопоэтических стволовых клеток, A. fumigatus инвазивного аспергиллеза – 46 дней (2 – 866) (p = 0,171). Большинство пациентов с A. fumigatus инвазивным аспергиллезом (n = 10, 77 %) и A. не-fumigatus инвазивным аспергиллезом (n = 16, 80 %) в качестве стартовой противогрибковой терапии получали вориконазол. Терапия второй линии потребовалась 2 (10 %) пациентам с A. не-fumigatus инвазивным аспергиллезом (липосомальный амфотерицин В, эхинокандины и позаконазол) и 2 (15 %) пациентам с А. fumigatus инвазивным аспергиллезом (липосомальный амфотерицин В, вориконазол в комбинации с эхинокандином). Общая выживаемость пациентов с A. неfumigatus инвазивным аспергиллезом в течение 12 недель составила 55 %, A. fumigatus инвазивным асппергиллезом – 59,2 % (p = 0,617).   Выводы. A. niger – основной возбудитель инвазивного аспергиллеза, обусловленного A. non-fumigatus. Характеристики пациентов, их лечение и исходы достоверно не различались между группами A. не-fumigatus и A. fumigatus

    A framework for the development of a global standardised marine taxon reference image database (SMarTaR-ID) to support image-based analyses

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    Video and image data are regularly used in the field of benthic ecology to document biodiversity. However, their use is subject to a number of challenges, principally the identification of taxa within the images without associated physical specimens. The challenge of applying traditional taxonomic keys to the identification of fauna from images has led to the development of personal, group, or institution level reference image catalogues of operational taxonomic units (OTUs) or morphospecies. Lack of standardisation among these reference catalogues has led to problems with observer bias and the inability to combine datasets across studies. In addition, lack of a common reference standard is stifling efforts in the application of artificial intelligence to taxon identification. Using the North Atlantic deep sea as a case study, we propose a database structure to facilitate standardisation of morphospecies image catalogues between research groups and support future use in multiple front-end applications. We also propose a framework for coordination of international efforts to develop reference guides for the identification of marine species from images. The proposed structure maps to the Darwin Core standard to allow integration with existing databases. We suggest a management framework where high-level taxonomic groups are curated by a regional team, consisting of both end users and taxonomic experts. We identify a mechanism by which overall quality of data within a common reference guide could be raised over the next decade. Finally, we discuss the role of a common reference standard in advancing marine ecology and supporting sustainable use of this ecosystem
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