Publications by authors named "POPOV A"

We present here the synthesis and in-depth physicochemical characterization of a double hetero[7]helicene fused with four triazole rings at both helical ends. The comparison of this triazole-fused double helicene with the previously reported all-carbon and thiadiazole-fused analogs revealed the huge impact of the embedded aromatic rings on the photophysical features. The small structural variation of the terminal rings from thiadiazole to triazole caused a dramatic change of the photoluminescence quantum yields (PLQYs) from <1 % to 96 %, while the replacement of the terminal benzene rings with triazole rings induced a tenfold enhancement of the circularly polarized luminescence dissymmetry factor.

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The global spread of the metabolic syndrome, oncological and viral diseases forces researchers to pay increased attention to the secondary metabolites of marine hydrobionts, which often have a high therapeutic potential in the treatment of these pathologies and are effective components of functional food. The flavone luteolin (LT), as one of the most widely distributed and studied plant metabolites, is distinguished by a diverse spectrum of biological activity and a pleiotropic nature of the mechanism of action at the molecular, cellular and organismal levels. However, there is still practically no information on the spectrum of biological activity of its sulfated derivatives, which are widely represented in seagrasses of the genus Zostera.

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Research on the evolution of dog foraging and diet has largely focused on scavenging during their initial domestication and genetic adaptations to starch-rich food environments following the advent of agriculture. The Siberian archaeological record evidences other critical shifts in dog foraging and diet that likely characterize Holocene dogs globally. By the Middle Holocene, body size reconstruction for Siberia dogs indicates that most were far smaller than Pleistocene wolves.

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Multiparticle azimuthal correlations of prompt D^{0} mesons are measured in Pb-Pb collisions at a nucleon-nucleon center-of-mass energy of sqrt[s_{NN}]=5.02  TeV. For the first time, a four-particle cumulant method is used to extract the second Fourier coefficient of the azimuthal distribution (v_{2}) of D^{0} mesons as a function of event centrality and the D^{0} transverse momentum.

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A search for resonances decaying into a W boson and a radion, where the radion decays into two W bosons, is presented. The data analyzed correspond to an integrated luminosity of 138  fb^{-1} recorded in proton-proton collisions with the CMS detector at sqrt[s]=13  TeV. One isolated charged lepton is required, together with missing transverse momentum and one or two massive large-radius jets, containing the decay products of either two or one W bosons, respectively.

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Article Synopsis
  • A search for exclusive two-photon production via photon exchange in proton-proton collisions was conducted using data from the LHC in 2016, focusing on events with intact protons.
  • The analysis aimed to select events with a diphoton invariant mass above 350 GeV, ensuring both protons remained intact to minimize interference from strong interactions.
  • No events meeting the criteria were found, which allowed researchers to set new limits on two anomalous four-photon coupling parameters, revealing |ζ_{1}|<2.9×10^{-13} GeV^{-4} and |ζ_{2}|<6.0×10^{-13} GeV^{-4} at a 95% confidence level.
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Bismuth-based compounds are considered to be the best candidates for computed tomography (CT) imaging of gastrointestinal (GI) tract due to high X-ray absorption. Here, we report the introduction of polymer-coated bismuth oxychloride (BiOCl) nanosheets for highly efficient CT imaging in healthy mice and animal with colitis. We demonstrate simple, low cost and fast aqueous synthesis protocol which provides gram-quantity yield of chemically stable BiOCl nanosheets.

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Fullertubes are tubular fullerenes with nanotube-like middle section and fullerene-like endcaps. To understand how this intermediate form between spherical fullerenes and nanotubes is reflected in the vibrational modes, we performed comprehensive studies of IR and Raman spectra of fullertubes C-, C-, and C-. An excellent agreement between experimental and DFT-computed spectra enabled a detailed vibrational assignment and allowed an analysis of the localization degree of the vibrational modes in different parts of fullertubes.

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The B_{c}^{+} meson is observed for the first time in heavy ion collisions. Data from the CMS detector are used to study the production of the B_{c}^{+} meson in lead-lead (Pb-Pb) and proton-proton (pp) collisions at a center-of-mass energy per nucleon pair of sqrt[s_{NN}]=5.02  TeV, via the B_{c}^{+}→(J/ψ→μ^{+}μ^{-})μ^{+}ν_{μ} decay.

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Background: The potential loss of CD19 during targeted treatment of B cell precursor acute lymphoblastic leukemia (BCP-ALL) can hamper flow cytometric minimal residual disease (MRD) monitoring. In the current study, we present expression data for antigens that are candidates for CD19 substitution: surface CD22, CD24, CD10, and intracellular (i) CD79a.

Methods: Bone marrow samples from 519 consecutive children (below 18 y.

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The authors' aim was to improve the application of copper-catalyzed azide-alkyne cycloaddition in the synthesis of hybrids containing biologically significant nucleobases and L-ascorbic acid scaffolds by introducing an environmentally friendly and waste-free ball mill. Two series of hybrids with a purine, pyrrolo[2,3-]pyrimidine or 5-substituted pyrimidine attached to 2,3-dibenzyl-L-ascorbic acid via a hydroxyethyl- () or ethylidene-1,2,3-triazolyl () bridge were prepared by ball milling and conventional synthesis. The unsaturated 6-chloroadenine L-ascorbic acid derivative can be highlighted as a lead compound and showed strong antiproliferative activity against HepG2 (hepatocellular carcinoma) and SW620 (colorectal adenocarcinoma) cells.

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Realization of stable spin states in surface-supported magnetic molecules is crucial for their applications in molecular spintronics, memory storage or quantum information processing. In this work, we studied the surface magnetism of dimetallo-azafullerene Tb@CN, showing a broad magnetic hysteresis in a bulk form. Surprisingly, monolayers of Tb@CN exhibited a completely different behavior, with the prevalence of a ground state with antiferromagnetic coupling at low magnetic field and a metamagnetic transition in the magnetic field of 2.

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Growing anthropogenic activities are significantly influencing the environment and especially aquatic ecosystems. Therefore, there is an increasing demand to develop techniques for monitoring and assessing freshwater habitat changes so that interventions can prevent irrevocable damage. We explore an approach for screening the temperature-induced stress experienced by aquatic organisms owing to environmental variations.

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The development of effective biomedical technologies using magnetic nanoparticles (MNPs) for the tasks of oncotherapy and nanodiagnostics requires the development and implementation of new methods for the analysis of micro- and nanoscale distributions of MNPs in the volume of cells and tissues. The paper presents a new approach to three-dimensional analysis of MNP distributions - scanning magnetic force nanotomography as applied to the study of tumor tissues. Correlative reconstruction of MNP distributions and nanostructure features of the studied tissues made it possible to quantitatively estimate the parameters of three-dimensional distributions of composite nanoparticles based on silicon and iron oxide obtained by femtosecond laser ablation and injected intravenously and intratumorally into tumor tissue samples of B16/F1 mouse melanoma.

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Article Synopsis
  • High-quality single crystals of the organic semiconductor dibenzopentacene were grown using physical vapor transport, allowing researchers to determine its crystal structure for the first time through X-ray diffraction.
  • Polarization-dependent optical absorption measurements showed significant anisotropy in the crystal plane, with Davydov splitting measured at approximately 110 meV, slightly less than the 120 meV observed in pentacene.
  • Further analysis using electron energy-loss spectroscopy revealed exciton dispersion and showed that dibenzopentacene has smaller electron- and hole-transfer integrals compared to pentacene, indicating complex interactions involving Frenkel and charge-transfer excitons.
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The growing amount of synthetic polymeric materials is a great environmental problem that has to be solved as soon as possible. The main factor aggravating this problem is the abundance of products made from traditional synthetic polymer, such as packaging materials, cases, containers and other equipment with a short period of use, which quickly turns into polymer waste that pollutes the ecosystem for decades. In this paper, we consider the possibility of solving this problem by the development of biodegradable compositions based on polyolefins and elastomers.

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This work is addressing the selective hydrogenation of alkynols over hybrid catalysts containing Pd-nanoparticles, within newly synthesized hyper-cross-linked polystyrenes (HPS). Alkynols containing C, C, and C with a terminal triple bond, which are structural analogues or direct semi-products of fragrant substances and fat-soluble vitamins, have been studied. Selective hydrogenation was carried out in a batch mode (ambient hydrogen pressure, at 90 °C, in toluene solvent), using hybrid Pd catalysts with low metal content (less than 0.

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Aim: The aim of the study was to evaluate the incidence and prognostic impact of central nervous system (CNS) involvement in infants with B-cell precursor acute lymphoblastic leukemia (BCP-ALL), as well as its relation with minimal residual disease (MRD) data.

Methods: A total of 139 consecutive infants with BCP-ALL from the MLL-Baby trial were studied. Cerebrospinal fluid (CSF) samples were investigated by microscopy of cytospin slides.

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Left Ventricular Assist Device (LVAD) is currently implanted not only as a bridge to transplant or recovery but also as destination therapy. One factor, affecting the device performance and treatment adequacy negatively is the development of aortic valve insufficiency (AI) after the implantation. Herein, we introduce a minimally invasive partial sternotomy aortic valve replacement with an expandable bio-prosthesis in a 74-year-old LVAD patient with severe AI.

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We develop a three-dimensional (3D) fully self-consistent model for analysis of an ultrashort THz pulse propagation and amplification in a nonequilibrium plasma channel formed in xenon by a femtosecond UV laser pulse. The model is based on the self-consistent solution of a second order wave equation in the cylindrical geometry and the kinetic Boltzmann equation for the electron velocity distribution function (EVDF) at different points of the spatially inhomogeneous nonequilibrium plasma channel. We analyze the wide range of plasma and seed pulse parameters and reveal the optimal regimes for producing high intensity outgoing THz fields as well as highly unipolar THz pulses within the proposed mechanism.

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The prohibition of antibiotics has led to extensive research and use of phytogenic feed additives. James Barrie Kirkpatrick described four subspecies of eucalyptus (family Myrtaceae), including , in 1974. The maximum concentrations of quercetin-3D-glycoside (1703.

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Biochemical and structural analyses of purified proteins are essential for the understanding of their properties. However, many proteins are unstable and difficult to purify, hindering their characterization. The B2 proteins of the lasso peptide biosynthetic pathways are cysteine proteases that cleave precursor peptides during the maturation process.

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Dysprosium-oxide clusterfullerene DyO@(5)-C is a single-molecule magnet featuring antiferromagnetic superexchange Dy⋯Dy coupling the μ-O bridge, the strongest of its kind among {Dy} complexes with non-radical bridges.

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Using a data sample of proton-proton collisions collected by the CMS experiment at the LHC in 2017 and 2018 with an integrated luminosity of , the and decays are observed with significances exceeding 5 standard deviations. The resulting branching fraction ratios, measured for the first time, correspond to and , where the last uncertainty in the first ratio is related to the uncertainty in the ratio of production cross sections of and mesons, .

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To better understand the genetics of hearing loss, we performed a genome-wide association meta-analysis with 125,749 cases and 469,497 controls across five cohorts. We identified 53/c loci affecting hearing loss risk, including common coding variants in COL9A3 and TMPRSS3. Through exome sequencing of 108,415 cases and 329,581 controls, we observed rare coding associations with 11 Mendelian hearing loss genes, including additive effects in known hearing loss genes GJB2 (Gly12fs; odds ratio [OR] = 1.

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