Publications by authors named "Korepanov V"

Aim: Comparative assessment of structural changes in cardiomyocyte mitochondria of the right atrial appendage and the mitochondrial respiratory function in peripheral blood leukocytes in a cohort of patients after acute decompensated heart failure (ADHF) and with stable chronic heart failure of ischemic etiology with reduced ejection fraction (CHFrEF) or moderately reduced ejection fraction (CHFmrEF) of the left ventricle.

Material And Methods: The study analyzed 40 micrographs of right atrial appendage cardiomyocytes obtained from 12 patients with CHFrEF and CHFmrEF. The study protocol was registered on ClinicalTrials.

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Photocatalysis offers a powerful approach for water purification from toxic organics, hydrogen production, biosolids processing, and the conversion of CO into useful products. Further advancements in photocatalytic technologies depend on the development of novel, highly efficient catalysts and optimized synthesis methods. This study aimed to develop a laser synthesis technique for bismuth oxyhalide nanoparticles (NPs) as efficient and multifunctional photocatalysts.

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Background: It has been reported that the mitochondrial respiratory dysfunction (MRD) is important mechanisms affecting the heart failure (HF) pathogenesis. We sought to evaluate the potential role of MRD of peripheral blood mononuclear cells (PBMC) in HF severity prediction in patients with cardioverter-defibrillator implantation indications.

Methods: In this single-center study patients with HF of New York Heart Association (NYHA) I-III functional class (FC) and cardioverter-defibrillator implantation indications underwent transthoracic echocardiography (TTE) and MRD assessment using PBMC.

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The development of chronic heart failure (CHF) was induced in 24-month-old male Wistar rats weighing 550-600 g by 4 subcutaneous injections of isoproterenol hydrochloride (ISO) at a dose of 10 mg/kg with 3-day intervals. The control group received injections of saline. The rats were euthanized 60 days after the last ISO/saline injection.

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We studied the relationship of inotropic responses of the isolated myocardium to stimulation of β-and β-adrenergic receptors (β-AR) with echocardiography parameters in 28 patients with coronary heart disease (CHD). Myocardial fragments (trabeculae of the right atrial appendage) were obtained during coronary artery bypass surgery. The inotropic response of the trabeculae was assessed in an isometric mode.

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Exposure of polytetrafluoroethylene (PTFE) to argon plasma results in chemical modification of the polymer near the surface. Interestingly, PTFE modification can be induced by the sub-band gap ultraviolet (UV) irradiation. In the latter case, the changes in the chemical structure are very subtle, and they are practically invisible to conventional experimental techniques.

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Background And Aims: Cardiopulmonary bypass (CPB) and circulatory arrest (CA) can induce intestinal injury and consequently lead to multiple organ dysfunction. Nitric oxide (NO) has protective effects, but its effect on the intestine has not been studied. The study aimed to investigate intestinal injury variables and prove the intestinal protective effects of exogenous nitric oxide when modelling CPB and CA in an experiment.

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We studied the respiratory activity of mitochondria in peripheral blood leukocytes from 36 patients with coronary heart disease (CHD) and a history of ventricular tachyarrhythmias required cardioverter-defibrillator implantation. The measurements were carried out in incubation buffers with different oxidation substrates (succinate and pyruvate-malate mixture). In pyruvate-malate incubation buffer, oxygen consumption rate and respiratory control coefficients in patients with triggered device did not differ significantly from those in patients without cardioverter-defibrillator triggering.

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Regenerative processes in the liver were studied in 3-month-old (young) and 9-month-old (aged) male Wistar rats on day 1 after 30 and 70% hepatectomy. Regardless of the resected liver volume, shifts in the biochemical parameters of the serum in aged rats were more pronounced than in young animals. After 30% hepatectomy, no age differences in the rate of hepatic regeneration were found, while after 70% liver resection this parameter was higher in young rats.

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Memristors, resistive switching memory devices, play a crucial role in the energy-efficient implementation of artificial intelligence. This study investigates resistive switching behavior in a lateral 2D composite structure composed of bilayer graphene and 2D diamond (diamane) nanostructures formed using electron beam irradiation. The resulting bigraphene/diamane structure exhibits nonlinear charge carrier transport behavior and a significant increase in resistance.

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Thermally stable films were obtained from a water-based polyurethane (PU) dispersion with small (0.1-1.5 wt.

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Baseline estimation in vibrational spectroscopy can be done efficiently with Tikhonov regularization. The state-of-the-art approaches, based on asymmetric weighting, require an additional parameter. Besides λ, the penalty for the second derivative, they introduce the asymmetry parameter that sets different weights for the points above and below the baseline.

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In the presented paper, we studied bilayer CVD graphene transferred to a langasite substrate and irradiated with a focused electron beam through a layer of polymethyl methacrylate (PMMA). Changes in the Raman spectra and an increase in the electrical resistance of bigraphene after irradiation indicate a local phase transition associated with graphene diamondization. The results are explained in the framework of the theory of a chemically induced phase transition of bilayer graphene to diamane, which can be associated with the release of hydrogen and oxygen atoms from PMMA and langasite due to the "knock-on" effect, respectively, upon irradiation of the structure with an electron beam.

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Polyphthalocyanines (PPCs) are a new and promising class of two dimensional materials offering versatile avenues for next generation electronic devices. For organic spintronic devices, PPCs can be engineered to tailor the electric and magnetic properties. In this work, we investigate PPC's monolayers with embedded transition metal atoms (TM = Fe, Ni, Cu), utilizing first principle calculations based on spin-polarized generalized gradient approximation (SGGA).

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β1-adrenergic receptors (β1-AR) directly affect on intracardiac hemodynamic and the ability of the heart to tolerate physical activity by regulating its inotropic and chronotropic functions. Severe hypersympathicotonia, specific to coronary artery disease (CAD) and chronic heart failure (HF), leads to impaired functioning of β1-AR. The aim of this research was to assess the expression level of the β1-AR ADRB1 gene in the myocardium, to evaluate the β-adrenergic reactivity of the membrane (β-ARM) of erythrocytes, and to analyze the association of these parameters with myocardial contractile dysfunction in patients with a myocardial infarction (MI) in the past and without it.

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As we know, defects caused in the synthetic process of metal halide perovskite are the most difficult to overcome, and greatly limit their photoelectric performances. Herein, a post-doped strategy was utilized to achieve an interesting morphology evolution from a standard octahedron to a snowflake-like sheet during the Mn-doped CsNaBiCl process, which realizes the obvious photoluminescence quantum efficiency (PLQY) enhancement of the CsNaBiCl:Mn phosphor. This surprising evolution is ascribed to the morphology collapse and reconstruction induced by Mn exchange.

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The alkaline activation of a carbonized graphene oxide/dextrin mixture yielded a carbon-based nanoscale material (AC-TR) with a unique highly porous structure. The BET-estimated specific surface area of the material is 3167 m/g, which is higher than the specific surface area of a graphene layer. The material has a density of 0.

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The poor water resistance property of a commercial Mn-activated narrow-band red-emitting fluoride phosphor restricts its promising applications in high-performance white LEDs and wide-gamut displays. Herein, we develop a structural rigidity-enhancing strategy using a novel KHF:Mn precursor as a Mn source to construct a proton-containing water-resistant phosphor K(H)TiF:Mn (KHTFM). The parasitic [HMnF] complexes in the interstitial site from the fall off the KHF:Mn are also transferred to the KTiF host by ion exchange to form KHTFM with rigid bonding networks, improving the water resistance and thermostability of the sample.

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We studied respiratory activity and microviscosity of mitochondrial membranes from the left ventricular myocardium of 2-month-old (n=8) and 15-month-old (n=8) rats. The respiratory control (RC) during substrate phosphorylation was calculated as the ratio of oxygen absorption rates in the presence of ADP and after its utilization. In 2-month-old rats, RC was 4.

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A graphene oxide aerogel (GOA) was formed inside a melamine sponge (MS) framework. After reduction with hydrazine at 60 °C, the electrical conductive nitrogen-enriched rGOA-MS composite material with a specific density of 20.1 mg/cm was used to fabricate an electrode, which proved to be a promising electrocatalyst for the oxygen reduction reaction.

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Coupling between vibrational modes is essential for energy transfer and dissipation in condensed matter. For water, different O-H stretch modes are known to be very strongly coupled both within and between water molecules, leading to ultrafast dissipation and delocalization of vibrational energy. In contrast, the information on the vibrational coupling of the H-O-H bending mode of water is lacking, even though the bending mode is an essential intermediate for the energy relaxation pathway from the stretch mode to the heat bath.

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Article Synopsis
  • Tuning crystal phase transformations is essential for developing ideal phosphor polymorphs, which impact their optical properties and stability.
  • The study investigates the phase transformation of Mn-doped KGeF, revealing that introducing HF solution and Si ions can create different KGF forms.
  • Si-doped hexagonal KGF exhibits the best stability and photoluminescence, with phase transformation linked to a precipitation-dissolution balance and ionic exchange mechanisms.
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For nanoscale systems such as nanoparticles and 3D-bonded networks, the range of spatial coherence is well reflected in the Raman spectral pattern. For confined, or localized, phonons, the range of q-points contributing to the spectrum depends on the phonon confinement length, which makes it possible to derive size information from the spectra. In this work, the Raman spectrum of vitreous silica is described as localized phonons of an SiO network.

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We study Raman spectra of ZnO nanoparticles of 5-12 nm size in the whole range of the first-order phonon bands. We apply the 3D phonon confinement model (PCM) for the interpretation of the observed Raman spectra. It is found that PCM is well applicable to the acoustic modes as well as to the optical ones, despite the fact that PCM has been thought not to be suitable for acoustic phonons.

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