21 results match your criteria: "Semenov Federal Research Center for Chemical Physics Russian Academy of Sciences[Affiliation]"

The results of a comprehensive investigation into the structure and properties of nanodiamond soot (NDS), obtained from the detonation of various explosive precursors (trinitrotoluene, a trinitrotoluene/hexogen mixture, and tetryl), are presented. The colloidal behavior of the NDS particles in different liquid media was studied. The results of the scanning electron microscopy, dynamic light scattering, zeta potential measurements, and laser diffraction analysis suggested a similarity in the morphology of the NDS particle aggregates and agglomerates.

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Excessive beta oscillations in the subthalamic nucleus are established as a primary electrophysiological biomarker for motor impairment in Parkinson's disease and are currently used as feedback signals in adaptive deep brain stimulation systems. However, there is still a need for optimization of stimulation parameters and the identification of optimal biomarkers that can accommodate varying patient conditions, such as ON and OFF levodopa medication. The precise boundaries of 'pathological' oscillatory ranges, associated with different aspects of motor impairment, are still not fully clarified.

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Glycerol-(9,10-trioxolane) trioleate (OTOA) is a promising material that combines good plasticizing properties for PLA with profound antimicrobial activity, which makes it suitable for application in state-of-the-art biomedical and packaging materials with added functionality. On the other hand, application of OTOA in PLA-based antibacterial materials is hindered by a lack of knowledge on kinetics of the OTOA release. In this work, the release of glycero-(9,10-trioxolane) trioleate (OTOA) from PLA films with 50% OTOA content was studied during incubation in normal saline solution, and for the first time, the kinetics of OTOA release from PLA film was evaluated.

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Clinical asymmetry in Parkinson's disease is characterized by prevalence of subthalamic pause-burst neurons and alpha-beta oscillations.

Clin Neurophysiol

September 2024

Laboratory of Human Cell Neurophysiology, N.N. Semenov Federal Research Center for Chemical Physics Russian Academy of Sciences, 119991, Kosygina str.4, Moscow, Russian Federation; Moscow Institute of Physics and Technology, 141701, 9 Institutskiy per., Dolgoprudny, Moscow Region, Russian Federation.

Article Synopsis
  • * During surgery, we analyzed neuronal activity and local field potentials, discovering differences in neuron firing patterns between the more affected and less affected sides of the brain.
  • * Our findings suggest that increased pause-burst neurons in the subthalamic nucleus may be linked to Parkinson's disease symptoms, especially in the context of movement issues like bradykinesia and rigidity.
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Copolymers based on vinylidene fluoride are potential materials for ferroelectric memory elements. The trend in studies showing that a decrease in the degree of crystallinity can lead to an unexpected increase in the electric breakdown field is noted. An analysis of the literature data reveals that in fluorine-containing ferroelectric polymers, when using a bipolar triangular field, the hysteresis loop has an unclosed shape, with each subsequent loop being accompanied by a decrease in the dielectric response.

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Significance: Preparation of a recipient cytoplast by oocyte enucleation is an essential task for animal cloning and assisted reproductive technologies in humans. The femtosecond laser is a precise and low-invasive tool for oocyte enucleation, and it should be an appropriate alternative to traditional enucleation by a microneedle aspiration. However, until recently, the laser enucleation was performed only with applying a fluorescent dye.

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Lipids are the most abundant but poorly explored components of the human brain. Here, we present a lipidome map of the human brain comprising 75 regions, including 52 neocortical ones. The lipidome composition varies greatly among the brain regions, affecting 93% of the 419 analyzed lipids.

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Self-assembly of new donor-acceptor systems based on (5,10,15,20-tetraphenylporphinato)manganese(III)/(5,10,15,20-tetra-4-tert-butylphenylporphinato)manganese(III)/(octakis(4-tert-butylphenyl)tetraazaporphinato)manganese(III) acetate ((AcO)MnTPP/(AcO)MnTBPP/(AcO)MnTAP) and 4-(10-phenylanthracen-9-yl)pyridine (PyAn) was studied using fluorescence spectroscopy and mass spectrometry. It was found that the coordination complexes of 1 : 1 composition (dyads) are formed in toluene. The spectral properties, the chemical structures and redox behavior of the dyads were described using H NMR, IR, ESR spectroscopy and cyclic voltammetry, respectively.

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To design high-energy-density materials of a new level, it is necessary to develop methods for the functionalization of energetic scaffolds, which will make it possible to tune their physicochemical and energetic properties. For this reason, we have elaborated an approach for synthesizing a new series of energetic cage compounds with advanced properties by introducing the -cyano group into the polynitro hexaazaisowurtzitane framework. The structures of the obtained substances were fully characterized with a combination of methods, including multinuclear (H, C{H}, N, and N{H}) NMR and IR spectroscopy, high-resolution mass spectrometry, X-ray diffraction analysis, electron microscopy and quantum chemical calculations.

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The product of ozonolysis, glycero-(9,10-trioxolane)-trioleate (ozonide of oleic acid triglyceride, [OTOA]), was incorporated into polylactic acid/polycaprolactone (PLA/PCL) blend films in the amount of 1, 5, 10, 20, 30 and 40% /. The morphological, mechanical, thermal and antibacterial properties of the biodegradable PLA/PCL films after the OTOA addition were studied. According to DSC and XRD data, the degree of crystallinity of the PLA/PCL + OTOA films showed a general decreasing trend with an increase in OTOA content.

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DYT1 dystonia: Neurophysiological properties of the pallidal activity.

Parkinsonism Relat Disord

July 2023

N.N. Semenov Federal Research Center for Chemical Physics Russian Academy of Sciences, Novatorov st. 7A-1, Moscow, Russian Federation; Moscow Institute of Physics and Technology, 9 Institutskiy per., Dolgoprudny, Moscow Region, Russian Federation.

Objectives: The aim of this paper is to find the differences in the physiology of the pallidal neurons in DYT1 and non-DYT1 dystonia.

Methods: We performed microelectrode recording of the single unit activity in both segments of the globus pallidus during stereotactic implantation of electrodes for deep brain stimulation (DBS).

Results: We found a reduced firing rate, reduced burst rate, and increased pause index in both pallidal segments in DYT1.

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The noncovalent interactions of (5,10,15,20-tetra(4-methylphenyl)porphinato)cobalt(II) (CoTTP) with C and 1-N-methyl-2-(pyridin-4-yl)-3,4-fullero[60]pyrrolidine (PyC) were studied in toluene using absorption and fluorescence titration methods. The self-assembly in the 2:1 complexes (the triads) (C)CoTTP and (PyC)CoTTP was established. The bonding constants for (C)CoTTP and (PyC)CoTTP are defined to be (3.

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Background: Mild traumatic brain injury (mTBI) causes a number of molecular and cellular alterations. There is evidence of an imbalance between the main excitatory (glutamate, Glu) and the main inhibitory (gamma-aminobutyric acid [GABA]) neurotransmitters following mTBI. In vivo human GABA-Glu balance studies following mTBI are sparse.

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Recipient cytoplast preparation, commonly performed by DNA aspiration with a needle, inevitably leads to the loss of reprogramming factors. As an alternative to the traditional enucleation technique, femtosecond laser enucleation can eliminate DNA effectively without loss of reprogramming factors and without oocyte puncturing. In this work we have performed oocyte enucleation by destructing the metaphase plate using a 795 nm femtosecond laser.

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A method of treatment of a new coronavirus infection COVID-19 in patients undergoing high flow oxygenation is proposed and technically implemented; the method is based on high-dose inhalation of gaseous nitric oxide (NO) with the patient's spontaneous breathing. The results of the treatment of this disease demonstrating the high efficiency of the new method are presented. A possible mechanism of the blocking effect of high doses of inhaled nitric oxide on the replication of the SARS-CoV-2 virus is discussed; it is based on the formation of dinitrosyl iron complexes in the respiratory tract and lungs of COVID-19 patients with thiol-containing ligands acting as donors of NO and nitrosonium NO cations in a living organism that have a cytotoxic effect on the SARS CoV-2 virus.

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The study was devoted to the creation of transparent electrodes based on highly conductive mesh structures. The analysis and reasonable choice of technological approaches to the production of such materials with a high Q factor (the ratio of transparency and electrical conductivity) were carried out. The developed manufacturing technology consists of the formation of grooves in a transparent substrate by photolithography methods, followed by reactive ion plasma etching and their metallization by chemical deposition using the silver mirror reaction.

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A kinetic model of polyunsaturated fatty acids (PUFAs) radical chain oxidation in micelles is presented, taking into account the diffusion of active intermediates between aqueous and organic phases, and its effect on the detailed mechanism of the process. The model made it possible to indirectly involve the structural changes of micelles and their kinetic characteristics by varying the actual values of the reactions rate constants. The modeling results are in good agreement with experimental data for the oxidation of methyl linoleate and linoleic acid.

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Article Synopsis
  • The study examines how well epoxy oligomer mixes with polysulfone (PSU) and polyethersulfone (PES) using optical interferometry and phase diagrams during the curing process.
  • Researchers analyzed the structural differences and mechanical properties, like tensile strength and crack resistance, of the cured modified systems through scanning electron microscopy and other physical tests.
  • The findings reveal that the initial solubility of the components significantly affects the resulting phase structure and the mechanical properties of the composite, with distinct behaviors related to the upper and lower critical solution temperatures of PSU and PES, respectively.
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A methodology for synthesizing a wide range of dumbbell-shaped, graft and bottlebrush polymers with all-siloxane nature (without carbosilane linkers) is suggested. These macroarchitectures are synthesized from SiOH-containing compounds-silanol (Et SiOH) and siloxanol dendrons of the first and second generations, with various peripheral substituents (Me or Et)-and from linear siloxanes comprising terminal and internal SiH groups by the Piers-Rubinsztajn reaction. Products and key building blocks are obtained in yields up to 95%.

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Ultra-sensitive elements for nanoscale devices capable of detecting single molecules are in demand for many important applications. It is generally accepted that the inevitable stochastic disturbance of a sensing element by its surroundings will limit detection at the molecular level. However, a phenomenon exists (stochastic resonance) in which the environmental noise acts abnormally: it amplifies, rather than distorts, a weak signal.

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Significance: Despite the importance of the cell membrane in regulation of drug activity, the influence of drug treatments on its physical properties is still poorly understood. The combination of fluorescence lifetime imaging microscopy (FLIM) with specific viscosity-sensitive fluorescent molecular rotors allows the quantification of membrane viscosity with high spatiotemporal resolution, down to the individual cell organelles.

Aim: The aim of our work was to analyze microviscosity of the plasma membrane of living cancer cells during chemotherapy with cisplatin using FLIM and correlate the observed changes with lipid composition and cell's response to treatment.

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