25 results match your criteria: "Federal Research Center "Komi Scientific Center"[Affiliation]"

Simulation of reciprocal-space mapping using a new analytical solution of kinematical X-ray diffraction in a crystal.

Acta Crystallogr A Found Adv

January 2025

Institute of Physics and Mathematics, Federal Research Center `Komi Scientific Center, the Ural Branch of the Russian Academy of Sciences', Kommunisticheskaya st. 24, Syktyvkar, 167982, Russian Federation.

Article Synopsis
  • New analytical solutions have been developed to describe how a limited X-ray beam interacts with a thin crystal, specifically aimed at addressing diffraction.
  • This new method streamlines the calculation of reflected X-ray beam angles, making it far less computationally expensive than traditional numerical approaches.
  • The study involved simulating X-ray reciprocal-space mapping for a thin silicon crystal using both the new analytical solutions and established numerical methods, like 2D recurrence relations and Takagi-Taupin equations.
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Isobornyl and Isocamphyl Photostabilizers in Poly(lactic acid)-Based Electrospun Fibers.

Polymers (Basel)

March 2024

Institute of Chemistry, Federal Research Center "Komi Scientific Center", Ural Branch, Russian Academy of Sciences, 48 Pervomayskaya Str.,167982 Syktyvkar, Russia.

In this work, electrospun polylactide fibers with new photostabilizing additives, 4-methyl-2,6-diisobornylphenol (DIBP) and N-isocamphylaniline (NICA), have been tested under the influence of UV-C radiation (254 nm). The changes in the polymers' chemical structure under UV-C radiation were revealed through the increase in absorption in the 3600-3100 cm region in regard to the FTIR spectra. In the samples that were irradiated for 1 h, the stabilizing effect of the photoprotectors became most noticeable as the difference in the content of the hydroxyl groups in stabilized and the pure PLA reached a maximum.

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The body surface potential mapping of the heart during the period of ventricular depolarization and the inotropic function of the ventricles were studied in rats under conditions of a translational model of post-infarction chronic heart failure developed by us. We revealed a statistically significant (p<0.001) correlation between the left-ventricular ejection fraction and the values of the maximum positive and negative extrema of the cardioelectric field on the body surface of rats with post-infarction chronic heart failure caused by anterior transmural myocardial infarction.

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In this study, we described physico-chemical properties of novel nanoformulation of photosensitizer-pyropheophorbide α 17-diethylene glycol ester (XL) (chlorophyll α derivative), revealing insights into antitumor activity and maintaining quality, meeting the pharmaceutical approach of new nanoformulation design. Our formulation, based on poly(lactic-co-glycolic acid) (PLGA) nanoparticles, increased XL solubility and selective tumor-targeted accumulation. In our research, we revealed, for the first time, that XL binding to polyvinyl alcohol (PVA) enhances XL photophysical activity, providing the rationale for PVA application as a stabilizer for nanoformulations.

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The island species-area relationship (ISAR) describes how species richness increases with increasing area of a given island or island-like habitat, such as freshwater lakes. While the ISAR is one of the most common phenomena observed in ecology, there is variation in both the form of the relationship and its underlying mechanisms. We compiled a global data set of benthic macroinvertebrates from 524 shallow freshwater lakes, ranging from 1 to 293,300 ha in area.

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Monoterpene thiols are one of the classes of natural flavors that impart the smell of citrus fruits, grape must and wine, black currants, and guava and are used as flavoring agents in the food and perfume industries. Synthetic monoterpene thiols have found an application in asymmetric synthesis as chiral auxiliaries, derivatizing agents, and ligands for metal complex catalysis and organocatalysts. Since monoterpenes and monoterpenoids are a renewable source, there are emerging trends to use monoterpene thiols as monomers for producing new types of green polymers.

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Histone acetyltransferases of the CBP/p300 family are involved in transcriptional regulation and many biological processes (cell proliferation and differentiation, development, and regulation of the stress response and metabolism). Overexpression and knockdown of the nejire (nej) gene (codes for an ortholog of human CBP/p300 proteins) in various tissues (the fat body, intestine, and nervous system) and at various stages of the life cycle (throughout all developmental stages or in adulthood only) were tested for effect on lifespan in the fruit fly Drosophila melanogaster. The activation of nej exerted a positive or a negative effect on the lifespan, depending on the induction mode and the sex.

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A novel amphiphilic cationic chlorin derivative was investigated as a promising photosensitizer for photodynamic therapy. Two cationic -N(CH) groups on the periphery of the macrocycle provide additional hydrophilization of the molecule and ensure its electrostatic binding to the mitochondrial membranes and bacterial cell walls. The presence of a hydrophobic phytol residue in the same molecule results in its increased affinity towards the phospholipid membranes while decreasing its stability towards aggregation in aqueous media.

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We studied the effect of antioxidants dibornol (2,6-diisobornyl-4-methylphenol) and its derivative (4-hydroxymethyl-2,6-diisobornylphenol), members of the alkylated phenols group, on the redox potential of male germ cells and their morphological and functional state in the rat model of pathospermia. Pharmacological effect was observed in animals treated with dibornol. The studied compounds led to the normalization of the antioxidant-prooxidant balance.

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Copper(ii) complexes with terpene derivatives of ethylenediamine: synthesis, and antibacterial, antifungal and antioxidant activity.

RSC Adv

March 2022

Institute of Chemistry, Komi Scientific Center, Ural Branch of the Russian Academy of Sciences 48, Pervomayskaya St. Syktyvkar 167000 Komi Republic Russian Federation

The synthesis of new chiral copper(ii) complexes with terpene derivatives of ethylenediamine and the results of studying their antibacterial, antifungal and antioxidant activity are discussed. All studied copper complexes (1-4) showed significantly higher antifungal activity against the strains of , and compared to the activity of the clinical antifungal drug amphotericin. High antibacterial activity of copper complexes with terpene derivatives of ethylenediamine was revealed against the (MRSA) strain, which is resistant to the reference antibiotic ciprofloxacin.

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Genetic mechanisms of aging in plants: What can we learn from them?

Ageing Res Rev

May 2022

Department of Forest Genetics and Forest Tree Breeding, Georg-August University of Göttingen, Büsgenweg 2, D-37077 Göttingen, Germany; Center for Integrated Breeding Research (CiBreed), Georg-August University of Göttingen, Albrecht-Thaer-Weg 3, D-37075 Göttingen, Germany; Laboratory of Population Genetics, N. I. Vavilov Institute of General Genetics, Russian Academy of Sciences, 3 Gubkin Street, 119333 Moscow, Russian Federation; Laboratory of Forest Genomics, Genome Research and Education Center, Department of Genomics and Bioinformatics, Siberian Federal University, 660036 Krasnoyarsk, Russian Federation; Scientific and Methodological Center, G. F. Morozov Voronezh State University of Forestry and Technologies, 8 Timiryazeva Street, 394036 Voronezh, Russian Federation. Electronic address:

Plants hold all records in longevity. Their aging is a complex process. In the presented review, we analyzed published data on various aspects of plant aging with focus on any inferences that could shed a light on aging in animals and help to fight it in human.

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Platelet aggregation causes various diseases and therefore challenges the development of novel antiaggregatory drugs. In this study, we report the possible mechanism of platelet aggregation suppression by newly synthesized myrtenol-derived monoterpenoids carrying different heteroatoms (sulphur, oxygen, or nitrogen). Despite all tested compounds suppressed the platelet aggregation in vitro, the most significant effect was observed for the S-containing compounds.

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Synthesis of new coumarin[1,3]oxazine derivatives of 7-hydroxy-6-isobornyl-4-methylcoumarin and their antioxidant activity.

Chem Biol Drug Des

December 2022

Institute of Chemistry, Komi Scientific Center, Ural Branch of the Russian Academy of Sciences, Syktyvkar, Russian Federation.

In this work, we synthesized a series of new 9,10-dihydro-2H,8H-chromeno[8,7e][1,3]oxazine-2-on derivatives which incorporate isobornylcoumarin and 1,3-oxazine moieties. A structure-antioxidant activity relationship was analyzed. A comparative evaluation of their radical scavenging activity, antioxidant and membrane-protective properties was carried out in test with DPPH, as well as on the models of Fe /ascorbate-initiated lipid peroxidation and oxidative hemolysis of mammalian red blood cells.

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X-ray Laue diffraction by sectioned multilayers. I. Pendellösung effect and rocking curves.

J Synchrotron Radiat

September 2021

Institute of Physics and Mathematics, Federal Research Center "Komi Scientific Center", The Ural Branch of the Russian Academy of Sciences, Syktyvkar 167982, Russian Federation.

Using the Takagi-Taupin equations, X-ray Laue dynamical diffraction in flat and wedge multilayers is theoretically considered. Recurrence relations are obtained that describe Laue diffraction in structures that are inhomogeneous in depth. The influence of sectioned depth, imperfections and non-uniform distribution of the multilayer period on the Pendellösung effect and rocking curves is studied.

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X-ray microbeam diffraction in a crystal.

Acta Crystallogr A Found Adv

March 2021

Institute of Physics and Mathematics, Federal Research Center `Komi Scientific Center', the Ural Branch of the Russian Academy of Sciences, Kommunisticheskaya Street 24, Syktyvkar 167982, Russian Federation.

Article Synopsis
  • The study examines how X-ray fields interact with crystals using dynamical scattering techniques, focusing on the differences between geometrical optics and the Fresnel approximation.
  • Results indicate that for broad X-ray beams, the scattering intensity patterns are similar in both approximations, but for narrow exits, edge diffraction effects are crucial.
  • The research includes detailed calculations of reciprocal-space maps and diffraction intensity distributions within the crystal.
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The purpose of work is to determine the ratio of amino acid enantimers in bioapatite of human teeth and the influence of pathological processes in periodontium on the degree of racemization of amino acids. Objects of research - enamel without signs of caries, root dentin of permanent teeth and enamel of human carious milk teeth (=16). Identification and determination of amino acid content in the samples was performed on a GC-17A gas chromatograph (Shimadzu, Chirasil-L-Val capillary column).

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Identification and first insights into the structure of chitin from the endemic freshwater demosponge Ochridaspongia rotunda (Arndt, 1937).

Int J Biol Macromol

November 2020

Institute of Electronics and Sensor Materials, TU Bergakademie Freiberg, Gustav-Zeuner-str. 3, 09599 Freiberg, Germany; Center for Advanced Technology, Adam Mickiewicz University, 61614 Poznan, Poland. Electronic address:

Studies on the identification, properties and function of chitin in sponges (Porifera), which are recognized as the first multicellular organisms on Earth, continue to be of fundamental scientific interest. The occurrence of chitin has so far been reported in 21 marine sponge species and only in two inhabiting fresh water. In this study, we present the discovery of α-chitin in the endemic demosponge Ochridaspongia rotunda, found in Lake Ohrid, which dates from the Tertiary.

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The Forest Observation System, building a global reference dataset for remote sensing of forest biomass.

Sci Data

October 2019

Department Foresterie et Environnement (DFR FOREN), Institut National Polytechnique Félix Houphouët-Boigny, INP-HB, Yamoussoukro, BP 2661, Côte d'Ivoire.

Forest biomass is an essential indicator for monitoring the Earth's ecosystems and climate. It is a critical input to greenhouse gas accounting, estimation of carbon losses and forest degradation, assessment of renewable energy potential, and for developing climate change mitigation policies such as REDD+, among others. Wall-to-wall mapping of aboveground biomass (AGB) is now possible with satellite remote sensing (RS).

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The ability of various pectin polysaccharides to modify the morphological structure of ice during the phase transitions from water to ice was studied. Pectins were isolated from Sosnowsky's hogweed Heracleum sosnowskyi Manden (heracleuman-N6HS), tansy Tanacetum vulgare L. (tanacetan-N7TVF), and Rauwolfia serpentina Benth callus (rauwolfian-N8RS).

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Background: Pectins have a large number of active -OH and -COOH groups (3), suggesting the presence of this group of substances specific cryoprotective effect.

Objective: This research is aimed at studying the ability of pectins (zosteran, apple pectin АU-701, E-440) to change the freezing temperature of glycerol, which can increase the effect in the cryopreservation of nuclear cells.

Methods: Using the cryoscopic method we studied the ability of pectins (zosteran, apple pectin AU-701, E-440) to change the freezing temperature of glycerol.

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A new water-soluble conjugate, consisting of a chlorin-based photosensitizing part, and a 4-arylaminoquinazoline moiety with high potential affinity to an epidermal growth factor receptors (EGFR) and vascular endothelial growth factor receptors (VEGFR), suitable for photodynamic therapy (PDT), was synthesized starting from methylpheophorbide-a in seven steps. An increased accumulation of this compound in A431 cells with high level of EGFR expression, in comparison with CHO and HeLa cells with low EGFR expression was observed. The prepared conjugate exhibits dark and photoinduced cytotoxicity at micromolar concentrations with IC/IC ratio of 11-18.

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Synthesis and membrane-protective activity of novel derivatives of α-mangostin at the C-4 position.

Bioorg Med Chem Lett

February 2015

Institute of Chemistry, Komi Scientific Center, Ural Branch of the Russian Academy of Sciences, 48, Pervomayskaya St., 167982 Syktyvkar, Komi Republic, Russian Federation.

A series of new C-4-derivatives of α-mangostin has been synthesized with the use of Mannich reaction and alkylation with 4-bromomethyl-2,6-dialkylphenols. It has been shown on a model of H2O2-induced erythrocyte hemolysis that the Mannich bases containing morpholinomethyl and piperidinomethyl fragments differ from parent α-mangostin by their high antioxidant and membrane-protective activity.

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NADPH oxidase activation was studied by detecting the reactive oxygen species (ROS) and the dynamics of neutrophil phagocytic activity in blood before freezing and one day after exposure to -20 degrees C in the presence of pectic polysaccharides. Pectins (excluding lemnan) were found to increase the phagocytic activity of neutrophils, promote the formation of ROS in these cells and enhance NADPH oxidase activity in the following order: bergenan, comaruman, lemnan, apiuman, and potamogetonan. Cryoprotective action of lemnan and comaruman was proposed to be related to their unique chemical structures.

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Biological consequences of increased natural radiation background for Microtus oeconomus Pall. populations.

J Environ Radioact

January 2008

Radioecology Department, Institute of Biology, Komi Scientific Center, Ural Division RAS, 28 Kommunisticheskaya ul., Syktyvkar 167982, Komi Republic, Russian Federation.

The results of long-term investigations (1981-1999) on the state of Microtus oeconomus Pall. (tundra vole) population, living under the increased natural radiation background for a long time (for more than 100 generations), are presented. Population density dynamics, morphophysiological parameters, state of the lipid peroxidation regulatory system in different tissues and the cytogenetic effects in bone marrow cells of animals have been analyzed.

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