The Pd(II) complexes Pd(Cp)(L)
BF
were synthesized via the reaction of cationic acetylacetonate complexes with cyclopentadiene in the presence of BF
∙OEt
(
= 2,
= 1: L = PPh
(
), P(
-Tol)
,
(
...-methoxyphenyl)phosphine (TOMPP),
-2-furylphosphine,
-2-thienylphosphine;
= 1,
= 1: L = dppf, dppp (
), dppb (
), 1,5-bis(diphenylphosphino)pentane;
= 1,
= 2 or 3: 1,6-bis(diphenylphosphino)hexane). Complexes
-
were characterized using X-ray diffractometry. The inspection of the crystal structures of the complexes enabled the recognition of (Cp
)⋯(Ph-group) and (Cp
)⋯(CH
-group) interactions, which are of C-H…π nature. The presence of these interactions was confirmed theoretically via DFT calculations using QTAIM analysis. The intermolecular interactions in the X-ray structures are non-covalent in origin with an estimated energy of 0.3-1.6 kcal/mol. The cationic palladium catalyst precursors with monophosphines were found to be active catalysts for the telomerization of 1,3-butadiene with methanol (
up to 2.4∙10
mol 1,3-butadiene per mol Pd with chemoselectivity of 82%). Complex Pd(Cp)(TOMPP)
BF
was found to be an efficient catalyst for the polymerization of phenylacetylene (PA) (catalyst activities up to 8.9 × 10
g
·(mol
·h)
were observed).
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Two series of the ferrite-based materials have been synthesized for an oxygen evolution reaction (OER) activity screening. Series 1 includes different types of the ferrites: S-type (BaFe2O4), R-type ...(BaFe4Ti2O11), M-type (BaFe12O19) and tetravalent substituted M-type (BaFe11TiO19, BaFe10Ti2O19). Series 2 consists of a divalent substituted M-type ferrites (BaFe11·9Co0·1O18.95, BaFe11·9Ni0·1O18.95, BaFe11·9Zn0·1O18.96). The thermodynamic and electrokinetic approaches have been used to evaluate the best catalyst from both series of samples. According to the thermodynamics BaFe11·9Ni0·1O18.95 is the most preferable, while according to the kinetics BaFe10Ti2O19 has the best Tafel slope.
•The electrocatalytic activity of different types of hexaferrites has been studied for the first time.•Hexagonal ferrites showed excellent oxygen and hydrogen evolution reaction processes.•It has been found that BaFe11·9Ni0·1O18.95 demonstrates the lowest overpotential in comparison with other.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
First results on
-dependence measurements in inclusive
meson production in
interactions (
, Al, Cu, Sn, and W) are presented at
GeV/
c
. The ratios of the differential cross sections of four of these ...nuclei to the differential cross section on aluminum were measured and the dependence of these cross sections on the atomic of the nucleus was studied. The measurements were carried out in the kinematic region of the Feynman variable
and transverse momentum
GeV/
c
.
mesons were detected in the decay mode
at the SPASCHARM experimental setup using negative charged beams at beamline 14 of the U-70 accelerator complex.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
In this work, a new hybridization of superconducting and ferromagnetic orders is demonstrated, promising for magnonics. By measuring the ferromagnetic and spin wave resonance absorption spectra of a ...magnetostatically coupled permalloy/niobium bilayer at different temperatures, magnetostatic spin wave resonances with unconventional dispersion are observed. The mechanism behind the modified dispersion, confirmed with micromagnetic simulations, implies screening of the alternating magnetostatic stray fields of precessing magnetic moments in the ferromagnetic layer by the superconducting surface in the Meissner state.
Magnetization dynamics is considered in a ferromagnetic film coupled inductively to a superconducting plane. As demonstrated, superconductivity promotes magnetostatic surface spin wave resonances with unconventional dispersion modified due to interaction of a spin wave with its mirrored image induced by the superconducting Meissner screening currents. The phenomenon offers application of superconductor/ferromagnet hybrid structures in magnonics.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Protein aggregation causes α-synuclein to switch from its physiological role to a pathological toxic gain of function. Under physiological conditions, monomeric α-synuclein improves ATP synthase ...efficiency. Here, we report that aggregation of monomers generates beta sheet-rich oligomers that localise to the mitochondria in close proximity to several mitochondrial proteins including ATP synthase. Oligomeric α-synuclein impairs complex I-dependent respiration. Oligomers induce selective oxidation of the ATP synthase beta subunit and mitochondrial lipid peroxidation. These oxidation events increase the probability of permeability transition pore (PTP) opening, triggering mitochondrial swelling, and ultimately cell death. Notably, inhibition of oligomer-induced oxidation prevents the pathological induction of PTP. Inducible pluripotent stem cells (iPSC)-derived neurons bearing SNCA triplication, generate α-synuclein aggregates that interact with the ATP synthase and induce PTP opening, leading to neuronal death. This study shows how the transition of α-synuclein from its monomeric to oligomeric structure alters its functional consequences in Parkinson's disease.
In the present paper, the kinetics of the water extraction of bitumen from tar sand and crude oil or residual fuel oil from model contaminated soils under the effect of ultrasound is studied. The ...influence of process temperature, ultrasound power, the nature, and properties of the components of heterogeneous mixtures being separated, and the concentration of added alkaline reagents on the rate and degree of oil recovery is investigated. A functional form of the dependencies of separation efficiency on the mean size of solid particles and the temperature of a working medium is found. Optimum concentrations of reagents in the process solution are determined. It is shown that the spent solution of sodium silicate can be multiply used for separation, its reuse even speeding up the yield of oil in the initial period. Taking into account obtained results, a multipurpose pilot plant with a flow-type reactor for ultrasonic extraction of petroleum and its products from contaminated soils was manufactured and tested. During tests, the purification of sandy soil contaminated with residual fuel oil was carried out which verified the results of laboratory studies.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Aggregation of the misfolded proteins β-amyloid, tau, huntingtin, and α-synuclein is one of the most important steps in the pathology underlying a wide spectrum of neurodegenerative disorders, ...including the two most common ones—Alzheimer’s and Parkinson’s disease. Activity and toxicity of these proteins depends on the stage and form of aggregates. Excessive production of free radicals, including reactive oxygen species which lead to oxidative stress, is proven to be involved in the mechanism of pathology in most of neurodegenerative disorders. Both reactive oxygen species and misfolded proteins play a physiological role in the brain, and only deregulation in redox state and aggregation of the proteins leads to pathology. Here, we review the role of misfolded proteins in the activation of ROS production from various sources in neurons and glia. We discuss if free radicals can influence structural changes of the key toxic intermediates and describe the putative mechanisms by which oxidative stress and oligomers may cause neuronal death.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Abstract
Eukaryotic chromosomes are spatially segregated into topologically associating domains (TADs). Some TADs are attached to the nuclear lamina (NL) through lamina-associated domains (LADs). ...Here, we identified LADs and TADs at two stages of Drosophila spermatogenesis – in bamΔ86 mutant testes which is the commonly used model of spermatogonia (SpG) and in larval testes mainly filled with spermatocytes (SpCs). We found that initiation of SpC-specific transcription correlates with promoters’ detachment from the NL and with local spatial insulation of adjacent regions. However, this insulation does not result in the partitioning of inactive TADs into sub-TADs. We also revealed an increased contact frequency between SpC-specific genes in SpCs implying their de novo gathering into transcription factories. In addition, we uncovered the specific X chromosome organization in the male germline. In SpG and SpCs, a single X chromosome is stronger associated with the NL than autosomes. Nevertheless, active chromatin regions in the X chromosome interact with each other more frequently than in autosomes. Moreover, despite the absence of dosage compensation complex in the male germline, randomly inserted SpG-specific reporter is expressed higher in the X chromosome than in autosomes, thus evidencing that non-canonical dosage compensation operates in SpG.
Graphical Abstract
Graphical Abstract
•1. Start of SpC-specific transcription correlates with detachment from the nuclear lamina and with spatial insulation. •2. SpC-specific genes are associated in transcription factories upon activation. •3. Non-canonical dosage compensation mechanism operates in the male germline.
Protein aggregation and abnormal lipid homeostasis are both implicated in neurodegeneration through unknown mechanisms. Here we demonstrate that aggregate-membrane interaction is critical to induce a ...form of cell death called ferroptosis. Importantly, the aggregate-membrane interaction that drives ferroptosis depends both on the conformational structure of the aggregate, as well as the oxidation state of the lipid membrane. We generated human stem cell-derived models of synucleinopathy, characterized by the intracellular formation of α-synuclein aggregates that bind to membranes. In human iPSC-derived neurons with SNCA triplication, physiological concentrations of glutamate and dopamine induce abnormal calcium signaling owing to the incorporation of excess α-synuclein oligomers into membranes, leading to altered membrane conductance and abnormal calcium influx. α-synuclein oligomers further induce lipid peroxidation. Targeted inhibition of lipid peroxidation prevents the aggregate-membrane interaction, abolishes aberrant calcium fluxes, and restores physiological calcium signaling. Inhibition of lipid peroxidation, and reduction of iron-dependent accumulation of free radicals, further prevents oligomer-induced toxicity in human neurons. In summary, we report that peroxidation of polyunsaturated fatty acids underlies the incorporation of β-sheet-rich aggregates into the membranes, and that additionally induces neuronal death. This suggests a role for ferroptosis in Parkinson's disease, and highlights a new mechanism by which lipid peroxidation causes cell death.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The work is devoted to the transverse polarization (
) of
-hyperons and corresponding antihyperons produced in meson–proton and meson–nuclear interactions in inclusive reactions. The currently ...available experimental data are compared with calculations based on the chromomagnetic polarization of quark (CPQ) model. The main features of the CPQ model are the prediction of hyperon polarization oscillations depending on the Feynman variable
in the case of a sufficiently strong chomomagnetic field and resonant dependence of the polarization on the c.m. energy (
) for some reactions. Calculations based on the CPQ model were performed for still unexplored kinematic regions and various targets and can be tested in the SPASCHARM experiment at the NRC ‘‘Kurchatov Institute’’—IHEP.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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