Monolayers of transition metal dichalcogenides (TMDCs) demonstrate plenty of unique properties due to the band structure. Symmetry breaking brings second-order susceptibility to meaningful values resulting in the enhancement of corresponding nonlinear effects. Cooling the TMDC films to cryogenic temperatures leads to the emergence of two distinct photoluminescence peaks caused by the exciton and trion formation.
View Article and Find Full Text PDFNanostructures proved to be versatile platforms to control the electromagnetic field at subwavelength scale. Indeed, high-quality-factors nanocavities have been used to boost and control nonlinear frequency generation by increasing the light-matter interaction. However, nonlinear processes are triggered by high-intensities, which are provided by ultrashort laser pulses with large bandwidth, which cannot be fully exploited in such devices.
View Article and Find Full Text PDFThe effect of a natural polysaccharide (hyaluronic acid (HA)) on the photocatalytic activity of methylene blue (MB) was studied both under model conditions (a tryptophan photooxidation reaction in water) and with in vitro experiments on and bacterial cultures. It was shown spectrophotometrically that, in the presence of HA, an increase in the optical density of the absorption bands λ = 665 nm and 620 nm-which correspond to the monomeric and dimeric forms of the dye, respectively-was observed in the EAS of the dye, while the ratio of the optical density of these bands remained practically unchanged. When adding HA to MB, the intensity of singlet oxygen O photoluminescence and the degree of fluorescence polarization of MB increase.
View Article and Find Full Text PDFPreviously, we described the mechanisms of development of autoimmune encephalomyelitis (EAE) in 3-month-old C57BL/6, Th, and 2D2 mice. The faster and more profound spontaneous development of EAE with the achievement of deeper pathology occurs in hybrid 2D2/Th mice. Here, the cellular and immunological analysis of EAE development in 2D2/Th mice was carried out.
View Article and Find Full Text PDFCystic fibrosis (CF) is a hereditary disease characterized by the progression of respiratory disorders, especially in adult patients. The purpose of the study was to identify volatile organic compounds (VOCs) as predictors of respiratory dysfunction, chronic respiratory infections of , , , and VOCs associated with severe genotype and highly effective modulator treatment (HEMT). Exhaled breath samples from 102 adults with CF were analyzed using PTR-TOF-MS, obtained during a forced expiratory maneuver and normal quiet breathing.
View Article and Find Full Text PDFBackground: Proton-transfer reaction time-of-flight mass spectrometry (PTR-TOF-MS) is a promising tool for a rapid online determination of exhaled volatile organic compounds (eVOCs) profiles in patients with cystic fibrosis (CF).
Objective: To detect VOC breath signatures specific to adult patients with CF compared with controls using PTR-TOF-MS.
Methods: 102 CF patients (54 M/48, mean age 25.
In this article, the specific features of competitive ionic and molecular transport in nanocomposite systems based on network membranes synthesized by radical polymerization of polyethylene glycol diacrylate in the presence of LiBF, 1-ethyl-3-methylimidazolium tetrafluoroborate, ethylene carbonate (EC), and TiO nanopowder (d~21 nm) were studied for H, Li, B, C, and F nuclei using NMR. The membranes obtained were studied through electrochemical impedance, IR-Fourier spectroscopy, DSC, and TGA. The ionic conductivity of the membranes was up to 4.
View Article and Find Full Text PDFThe hydration of ions and charge groups controls electro mass transfer through ion exchange systems. The self-diffusion and local mobility of water molecules as well as lithium cations in poly (4-styrenesulfonic acid) and its lithium, sodium and cesium salts were investigated for the first time using pulsed-field gradient NMR (PFG NMR) and NMR relaxation techniques. The temperature dependences of the water molecule and Li cation self-diffusion coefficients exhibited increasing self-diffusion activation energy in temperature regions below 0 °C, which is not due to the freezing of parts of the water.
View Article and Find Full Text PDFElementary processes of electro mass transfer in the nanocomposite polymer electrolyte system by pulse field gradient, spin echo NMR spectroscopy and the high-resolution NMR method together with electrochemical impedance spectroscopy are examined. The new nanocomposite polymer gel electrolytes consisted of polyethylene glycol diacrylate (PEGDA), salt LiBF and 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIBF) and SiO nanoparticles. Kinetics of the PEGDA matrix formation was studied by isothermal calorimetry.
View Article and Find Full Text PDFThe interconnection of ionogenic channel structure, cation hydration, water and ionic translational mobility was revealed in Nafion and MSC membranes based on polyethylene and grafted sulfonated polystyrene. A local mobility of Li, Na and Cs cations and water molecules was estimated via the H, Li, Na and Cs spin relaxation technique. The calculated cation and water molecule self-diffusion coefficients were compared with experimental values measured using pulsed field gradient NMR.
View Article and Find Full Text PDFThe effect of the composition of liquid electrolytes in the bulk and at the interface with the LiFePO cathode on the operation of a solid-state lithium battery with a nanocomposite polymer gel electrolyte based on polyethylene glycol diacrylate and SiO was studied. The self-diffusion coefficients on the 7Li, 1H, and 19F nuclei in electrolytes based on LiBF and LiTFSI salts in solvents (gamma-butyrolactone, dioxolane, dimethoxyethane) were measured by nuclear magnetic resonance (NMR) with a magnetic field gradient. Four compositions of the complex electrolyte system were studied by high-resolution NMR.
View Article and Find Full Text PDFThe influence of chitosan (CS) and amphiphilic polymers (AP: pluronic F108 and polyvinylpyrrolidone (PVP)) on the photocatalytic activity of rose bengal (RB) in a model reaction of tryptophan photo-oxidation in phosphate-buffered saline (PBS) was studied. It was shown that in the presence of CS, the effective rate constant of tryptophan photo-oxidation catalyzed by RB in PBS solution decreases by a factor of two. This is due to the ionic interaction of the RB with the chitosan.
View Article and Find Full Text PDFGyrate chorioretinal atrophy (GCA) is a rare hereditary disease with certain complications; one extremely rare complication of GCA is foveoschisis. For the first time in Russian ophthalmology, a 10-year-old female child has been described to have genetically verified GCA associated with the gene in combination with ornithinemia and foveoschisis. The diagnosis was made on the basis of fundus examination, perimetry data, autofluorescence, optical coherence tomography, fluorescence angiography, electroretinography, mass spectrometry with confirmation by molecular genetic research.
View Article and Find Full Text PDFNMR is the method of choice for molecular and ionic structures and dynamics investigations. The present review is devoted to solvation and mobilities in solid electrolytes, such as ion-exchange membranes and composite materials, based on cesium acid sulfates and phosphates. The applications of high-resolution NMR, solid-state NMR, NMR relaxation, and pulsed field gradient H, Li, C, F, Na, P, and Cs NMR techniques are discussed.
View Article and Find Full Text PDFThis review is devoted to different types of novel polymer electrolytes for lithium power sources developed during the last decade. In the first part, the compositions and conductivity of various polymer electrolytes are considered. The second part contains NMR applications to the ion transport mechanism.
View Article and Find Full Text PDFBackground: Non-alcoholic steatohepatitis (NASH) is an inflammatory subtype of non-alcoholic fatty liver disease (NAFLD) and recent non-invasive test, MACK-3, demonstrated good diagnostic characteristics for fibrosis in several studies. The aim of our study was to assess the liver state using the non-invasive MACK-3 Test, and its link with liver fibrosis stage, inflammatory activity, steatosis, and metabolic markers in NAFLD patients with hypertension (HT).
Methods: Thirty adult NAFLD patients with HT, aged 30 to 60 years (mean age 46.
Here we report a reaction of the fullerene derivatives CArCl, which enables the substitution of Cl with thiophene residues and the formation of the novel family of -symmetrical C fullerene derivatives with six functional addends CArTh. The discovered reaction provided a straightforward approach to the synthesis of previously inaccessible multifunctional water-soluble fullerene derivatives, including the compounds with antiviral activity against human immunodeficiency and influenza viruses.
View Article and Find Full Text PDFThe results of NMR, and especially pulsed field gradient NMR (PFG NMR) investigations, are summarized. Pulsed field gradient NMR technique makes it possible to investigate directly the partial self-diffusion processes in spatial scales from tenth micron to millimeters. Modern NMR spectrometer diffusive units enable to measure self-diffusion coefficients from 10 m/s to 10 m/s in different materials on H, H, Li, C, F, Na, P, Cs nuclei.
View Article and Find Full Text PDFCystic fibrosis (CF) is the most common monogenic autosomal recessive disease, associated with pathogenic variants in the CFTR gene. The splicing variant c.3140-16T>A (3272-16T>A) has been described previously and, according to the Russian CF Patients Registry, occurs with a frequency of 0.
View Article and Find Full Text PDFCyclic oxoammonium salts and DMSO are known as important reagents for their diverse and unique reactivity. In the present work, we have studied the reaction of six- and five-membered oxoammonium salts with DMSO. The reaction includes ∼100% selective transfer of the O atom from the >N═O group to the S atom of DMSO and structural rearrangement of the remaining cationic framework, leading to the formation of hydrolytically unstable iminium salts.
View Article and Find Full Text PDFThe main particularities of sulfonate groups hydration, water molecule, and alkaline metal cation translation mobility were revealed by nuclear magnetic resonance (NMR) and ionic conductivity measurements techniques in cation-exchange membranes MSC based on cross-linked sulfonated polystyrene (PS) grafted on polyethylene with ion-exchange capacity of 2.5 mg-eq/g. Alkaline metal cation hydration numbers (h) calculated from temperature dependences of H chemical shift of water molecule for membranes equilibrated with water vapor at RH = 95% are 5, 6, and 4 for Li, Na, and Cs ions, respectively.
View Article and Find Full Text PDFRecently developed non-functional derivatives of polymethylsilsesquioxane (PMSSO) dendrimers of the first to fifth generation were characterized by 1H, 13C and 29Si NMR spectroscopy. The self-diffusion and NMR relaxation of PMSSO dendrimers in dilute solutions of toluene and melts were investigated in a wide temperature range (-50-80 °C). The hydrodynamic radii of dendrimers were determined from the self-diffusion coefficients measured in diluted solutions according to the Stokes-Einstein equation.
View Article and Find Full Text PDFPurpose: To assess the changes in photoreceptor retinal layers and the choroid in comparison with bioelectrical activity of the macula in patients with retinitis pigmentosa (RP).
Material And Methods: The study included 10 patients (20 phakic eyes) with RP. Mean age was 27±18.
We have synthesized a series of water-soluble polycarboxylic derivatives of [60]fullerene with a gradually changed polarity by combining three to five polar (ionic) malonate addends with two to zero hydrophobic dichlorobenzene units and explored their antiviral activity. It has been shown that decreasing the number of the ionogenic carboxylic groups in the molecules enhanced their antiviral activity against HIV-1 and suppressed their action against HIV-2. The obtained results implied that the charged states and hydrophobicity of the water-soluble polycarboxylic fullerene derivatives affect significantly their biological properties.
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