Publications by authors named "Dmitry Popov"

In this study, we report an easy approach for the production of aqueous dispersions of C fullerene with good stability. Maleic acid copolymers, poly(styrene--maleic acid) (SM), poly(N-vinyl-2-pyrrolidone--maleic acid) (VM) and poly(ethylene--maleic acid) (EM) were used to stabilize C fullerene molecules in an aqueous environment by forming non-covalent complexes. Polymer conjugates were prepared by mixing a solution of fullerene in N-methylpyrrolidone (NMP) with an aqueous solution of the copolymer, followed by exhaustive dialysis against water.

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Subducting sedimentary layer typically contains water and hydrated clay minerals. The stability of clay minerals under such hydrous subduction environment would therefore constraint the lithology and physical properties of the subducting slab interface. Here we show that pyrophyllite (AlSiO(OH)), one of the representative clay minerals in the alumina-silica-water (AlO-SiO-HO, ASH) system, breakdowns to contain further hydrated minerals, gibbsite (Al(OH)) and diaspore (AlO(OH)), when subducts along a water-saturated cold subduction geotherm.

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Gout is caused by monosodium urate (MSU) crystal deposition within joints. This leads to acute episodes of inflammation ("gout flares") driven by NLRP3 inflammasome activation in macrophages. Gout flares are frequently present during late night/early morning.

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Mechanisms of hexagonal close-packed (HCP) to body-centered cubic (BCC) phase transformation in Mg single crystals are observed using a combination of polychromatic beam Laue diffraction and monochromatic beam powder diffraction techniques under quasi-hydrostatic pressures of up to 58 ± 2 GPa at ambient temperature. Although experiments were performed with both He and Ne pressure media, crystals inevitably undergo plastic deformation upon loading to 40-44 GPa. The plasticity is accommodated by dislocation glide causing local misorientations of up to 1°-2°.

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Absorption of sufficiently energetic X-ray photons by a molecular system results in a cascade of ultrafast electronic relaxation processes which leads to a distortion and dissociation of its molecular structure. Here, we demonstrate that only decomposition of powdered cesium oxalate monohydrate induced by monochromatic X-ray irradiation under high pressure leads to the formation of cesium superoxide. Whereas, for an unhydrated form of cesium oxalate subjected to the same extreme conditions, only degradation of the electron density distribution is observed.

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Background: To determine the predictive value of mid-regional pro-adrenomedullin (MR-proADM) compared to routine clinical and laboratory parameters in patients with COVID-19.

Methods: A total of 135 adult patients hospitalized with COVID-19 were included in a prospective single-centre study. In addition to routine parameters, the levels of MR-proADM in blood plasma were measured on the day of hospitalization.

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High-Pressure Collaborative Access Team (HPCAT) is a synchrotron-based facility located at the Advanced Photon Source (APS). With four online experimental stations and various offline capabilities, HPCAT is focused on providing synchrotron x-ray capabilities for high pressure and temperature research and supporting a broad user community. Overall, the array of online/offline capabilities is described, including some of the recent developments for remote user support and the concomitant impact of the current pandemic.

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High-pressure single-crystal x-ray diffraction is used to experimentally map the electron-density distribution changes in (Fe,Mg)O as ferrous iron undergoes a pressure-induced transition from high- to low-spin states. As the bulk density and elasticity of magnesiowüstite-one of the dominant mineral phases of Earth's mantle-are affected by this electronic transition, our results have applications to geophysics as well as to validating first-principles calculations. The observed changes in diffraction intensities indicate a spin-transition-induced change in orbital occupancies of the Fe ion in general accord with crystal-field theory, illustrating the use of electron density measurements for characterizing high-pressure d-block chemistry and motivating further studies characterizing chemical bonding under pressure.

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A state of the art, custom-built direct-metal deposition (DMD)-based additive manufacturing (AM) system at the University of Michigan was used to manufacture 50Cu-50Fe alloy with tailored properties for use in high strain/deformation environments. Subsequently, we performed preliminary high-pressure compression experiments to investigate the structural stability and deformation of this material. Our work shows that the alpha (BCC) phase of Fe is stable up to ~16 GPa before reversibly transforming to HCP, which is at least a few GPa higher than pure bulk Fe material.

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Crystallographic theory based on energy minimization suggests austenite-twinned martensite interfaces with specific orientation, which are confirmed experimentally for various materials. Pressure-induced phase transformation (PT) from semiconducting Si-I to metallic Si-II, due to very large and anisotropic transformation strain, may challenge this theory. Here, unexpected nanostructure evolution during Si-I → Si-II PT is revealed by combining molecular dynamics (MD), crystallographic theory, generalized for strained crystals, and in situ real-time Laue X-ray diffraction (XRD).

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The blueschist to eclogite transition is one of the major geochemical-metamorphic processes typifying the subduction zone, which releases fluids triggering earthquakes and arc volcanism. Although glaucophane is an index hydrous mineral for the blueschist facies, its stability at mantle depths in diverse subduction regimes of contemporary and early Earth has not been experimentally determined. Here, we show that the maximum depth of glaucophane stability increases with decreasing thermal gradients of the subduction system.

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The bioprinting of heterogeneous organs is a crucial issue. To reach the complexity of such organs, there is a need for highly specialized software that will meet all requirements such as accuracy, complexity, and others. The primary objective of this review is to consider various software tools that are used in bioprinting and to reveal their capabilities.

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An Escherichia coli sequence type 31 isolate co-harbouring mcr-1 and bla genes on the plasmids of Incl2 and IncC groups, respectively, was recovered from a newborn with ventilator-associated pneumonia in Moscow, Russia. The convergence of polymyxin and carbapenem resistance and its expansion beyond Southeast Asia is a serious threat to human health.

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Article Synopsis
  • * Out of 13,595 patients surveyed, 26.14% received antimicrobials, primarily third-generation cephalosporins, and compliance with hospital antibiotic guidelines varied over the three studies, ranging from 66.8% to 74.8%.
  • * The study highlighted issues such as low documentation rates for treatment indications and stop dates, high rates of prolonged perioperative antibiotic use, and insufficient targeted therapy, suggesting a need for tailored antimicrobial stewardship programs in hospitals.
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is an extremely infectious and malignant pathogen among many bacteria species. The aim of this work is to provide a robust classification model that would be able to identify independent of the culture growth stage and the variations in bacteria concentration in suspension and also one that would be able to identify the pathogen among both taxonomically close species of the same genus and taxonomically distant species of different genera, using Fourier transform infrared spectroscopy (FTIR). In total, the spectra of 141 isolates of 17 bacteria have been used.

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Zirconium (Zr) has properties conducive to nuclear applications and exhibits complex behavior at high pressure with respect to the effects of impurities, deviatoric stress, kinetics, and grain growth which makes it scientifically interesting. Here, we present experimental results on the 300 K equation of state of ultra-high purity Zr obtained using the diamond-anvil cell coupled with synchrotron-based x-ray diffraction and electrical resistance measurements. Based on quasi-hydrostatic room-temperature compression in helium to pressure P  =  69.

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We report a synchrotron Laue diffraction study on the microstructure evolution in zirconium (Zr) as it undergoes a pressure-driven structural phase transformation, using a recently developed real time scanning x-ray microscopy technique. Time resolved characterizations of microstructure under high pressure show that Zr exhibits a grain enlargement across the α-Zr to ω-Zr structural phase transition at room-temperature, with nucleation and growth of ω-Zr crystals observed from initially a nano-crystalline aggregate of α-Zr. The observed grain enlargement is unusual since the enlargement processes typically require substantially high temperature to overcome the activation barriers for forming and moving of grain boundaries.

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The 1 : 1 acetylene-benzene cocrystal, CH·CH, was synthesized under pressure in a diamond anvil cell (DAC) and its evolution under pressure was studied with single-crystal X-ray diffraction and Raman spectroscopy. CH·CH is stable up to 30 GPa, nearly 10× the observed polymerization pressure for molecular acetylene to polyacetylene. Upon mild heating at 30 GPa, the cocrystal was observed to undergo an irreversible transition to a mixture of amorphous hydrocarbon and a crystalline phase with similar diffraction to i-carbon, a nanodiamond polymorph currently lacking a definitive structure.

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Vanadium diboride (VB) with an AlB-type structure has been synthesized at 8 GPa and 1700 K in a D-DIA-type multianvil apparatus. The obtained bulk modulus is B = 262(2) GPa with fixed B' = 4.0 for VB via high-pressure X-ray diffraction measurements.

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Background: Wearable assistive devices have demonstrated the potential to improve mobility outcomes for individuals with disabilities, and to augment healthy human performance; however, these benefits depend on how effectively power is transmitted from the device to the human user. Quantifying and understanding this power transmission is challenging due to complex human-device interface dynamics that occur as biological tissues and physical interface materials deform and displace under load, absorbing and returning power.

Methods: Here we introduce a new methodology for quickly estimating interface power dynamics during movement tasks using common motion capture and force measurements, and then apply this method to quantify how a soft robotic ankle exosuit interacts with and transfers power to the human body during walking.

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"Chemical precompression" through introducing impurity atoms into hydrogen has been proposed as a method to facilitate metallization of hydrogen under external pressure. Here we selected Ar(H), a hydrogen-rich compound with molecular hydrogen, to explore the effect of "doping" on the intermolecular interaction of H molecules and metallization at ultrahigh pressure. Ar(H) was studied experimentally by synchrotron X-ray diffraction to 265 GPa, by Raman and optical absorption spectroscopy to 358 GPa, and theoretically using the density-functional theory.

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Introduction: Prediction of complications and mortality after cardiac surgery is an important aspect of timely correction of these conditions. One possibility in this case is the use of biomarkers and some prognostic scores.

Aim Of The Study: To study the prognostic value of presepsin (PSP) as a predictor of postoperative complications development in cardiosurgical patients.

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The monochromator and focusing mirrors of the 16-BM-D beamline, which is dedicated to high-pressure research with micro-X-ray diffraction (micro-XRD) and X-ray absorption near edge structure (XANES) (6-45 keV) spectroscopy, have been recently upgraded. Monochromatic X-rays are selected by a Si (111) double-crystal monochromator operated in an artificial channel-cut mode and focused to 5 μm × 5 μm (FWHM) by table-top Kirkpatrick-Baez type mirrors located near the sample stage. The typical X-ray flux is ∼5 × 10(8) photons/s at 30 keV.

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Aim: To compare a new-generation fecal immunochemical test (FIT) with the leading guaiac-based test in detection of fecal occult blood (FOB) in colonoscopy-referral patients.

Patients And Methods: A cohort of 300 patients referred for colonoscopy was examined by two different tests for FOB: ColonView quick test (CV) (FIT test for haemoglobin (Hb) and haemoglobin/haptoglobin (Hb/Hp) complex) and HemoccultSENSA (HS) (quaiac test for Hb). Three fecal samples were tested and all subjects were examined by diagnostic colonoscopy with biopsy verification.

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