Activation of reparative processes of chronic wounds using photobiomodulation therapy (experimental study).

OBJECTIVE: Aim: The aim of the work was to study the ef f ect of photobiomodulation therapy on the regulation of disorders in the healing of chronic wounds at the remodeling stage using indicators of platelet aggregation activity, reactive oxygen species, platelet-derived growth factor, and interleukin-1ß. PATIENTS AND METHODS: Materials and Methods: The study included 3 groups of Wistar rats: intact animals and animals of the control and experimental groups, for which chronic wounds were simulated. Rats in the experimental group received photobiomodulation therapy once a day for 5 days. Wound defects of animals in the control group were fictitiously irradiated. The levels of reactive oxygen species, platelet-derived growth factor, and interleukin-1ß in the blood serum of animals were studied by enzyme immunoassay. The functional activity of platelets was measured on a computerized platelet aggregation analyzer using the turbidimetric method. Histological studies were carried out. RESULTS: Results: Changes in the expression of the studied indicators were found in the blood serum of animals with chronic wounds when using photobiomodulation therapy: an increase in platelet-derived growth factor concentrations, the levels of reactive oxygen species and interleukin-1ß did not have statistically signif i cant differences compared to the corresponding indicators of animals in the control group. There were no significant differences in the indicators of platelet aggregation activity in the control and experimental groups of animals. CONCLUSION: Conclusions: The findings suggest that photobiomodulation therapy may promote wound healing by increasing platelet-derived growth factor levels. Histological studies have shown that using photobiomodulation therapy helps reduce inflammation and better organization of collagen fibers in animals of the experimental group.

Rationalizing Graphene-ZnO Composites for Gas Sensing via Functionalization with Amines.

The rational design of composites based on graphene/metal oxides is one of the pillars for advancing their application in various practical fields, particularly gas sensing. In this study, a uniform distribution of ZnO nanoparticles (NPs) through the graphene layer was achieved, taking advantage of amine functionalization. The beneficial effect of amine groups on the arrangement of ZnO NPs and the efficiency of their immobilization was revealed by core-level spectroscopy, pointing out strong ionic bonding between the aminated graphene (AmG) and ZnO. The stability of the resulting Am-ZnO nanocomposite was confirmed by demonstrating that its morphology remains unchanged even after prolonged heating up to 350 °C, as observed by electron microscopy. On-chip multisensor arrays composed of both AmG and Am-ZnO were fabricated and thoroughly tested, showing almost tenfold enhancement of the chemiresistive response upon decorating the AmG layer with ZnO nanoparticles, due to the formation of p-n heterojunctions. Operating at room temperature, the fabricated multisensor chips exhibited high robustness and a detection limit of 3.6 ppm and 5.1 ppm for ammonia and ethanol, respectively. Precise identification of the studied analytes was achieved by employing the pattern recognition technique based on linear discriminant analysis to process the acquired multisensor response.

Predictors of fibrogenesis in children with JIA: a single-center pilot study.

BACKGROUND: Patients with rheumatological diseases are at high risk of developing irreversible fibrotic changes, both articular and extra-articular, as a result of tissue damage caused by the chronic phase of persistent inflammation. Thus, our purpose was to study early markers of fibrosis formation in children with juvenile idiopathic arthritis (JIA). METHODS: Seventy patients with juvenile idiopathic arthritis, namely, polyarthritis (64.29%) and oligoarthritis (35.71%) variant JIA (mean age 13.3 years, 64.29% girls, 35.71% boys), were included in this 4-year prospective study. Basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) levels were determined by ELISA kits. RESULTS: We evaluated bFGF (mean: 7478.21 pg/ml; min: 4171.56 pg/ml; max: 18,011.25 pg/ml) and VEGF (mean: 342.47 pg/ml; min: 23.68 pg/ml; max: 2158.91 pg/ml) levels in children with JIA. Children with JIA had a higher VEGF level when JIA onset occurred after 15 years of age and they had a high disease activity; additionally, a higher bFGF level was observed in children older than 14 years and in those with a JIA onset after 15 years of age, the oligoarticular variant, a moderate disease activity and regardless of MTX administration but more often when MTX was administered at a dosage from 10 to 12.5 mg/m2/week. CONCLUSIONS: Laboratory screening of fibrosis formation predictors could help identify patients who may be at greater risk of adverse outcomes. Children with JIA had higher bFGF and VEGF levels when JIA onset occurred after 15 years of age, depending on disease activity.

Revision of the oxygen reduction reaction on N-doped graphenes by grand-canonical DFT.

Nitrogen-doped graphenes were among the first promising metal-free carbon-based catalysts for the oxygen reduction reaction (ORR). However, data on the most efficient catalytic centers and their catalytic mechanisms are still under debate. In this work, we study the associative mechanism of the ORR in an alkaline medium on graphene containing various types of nitrogen doping. The free energy profile of the reaction is constructed using grand-canonical DFT at a constant electrode potential in combination with an implicit electrolyte model. It is shown that the reaction mechanism differs from the generally accepted one and depends on the surface potential and doping type. In particular, as the potential decreases, coupled electron-proton transfer changes to sequential electron and proton transfer, and the potential at which this occurs depends on the doping type. It has been shown that oxygen chemisorption is the limiting step. The electrocatalytic mechanism of the nitrogen dopants involves reducing the oxygen chemisorption energy. Calculations predict that, at different potentials, different types of nitrogen impurities most effectively catalyze the ORR.

Synthesis and Study of Organic Nanostructures Fabricated by Inclusion of 2-Methylbenzimidazole Molecules in Nanotubes of Chrysotile Asbestos, Mesoporous Silica, and Nanopores of Borate Glasses.

New organic nanostructures were synthesized by introducing 2-methylbenzimidazole (MBI) molecules from a melt, gas phase, or alcoholic solution into nanosized voids of borate porous glasses (PG), nanotubes of chrysotile asbestos (ChA), and mesoporous silica (MS). The incorporation of MBI into borate glasses with different pore sizes is accompanied by the appearance of several phases formed by nanocrystallites which have a MBI crystal structure, but somewhat differ in lattice parameters. The size of some crystallites significantly exceeds the size of nanopores, which indicates the presence of long-scale correlations of the crystal structure. The size of MBI nanocrystallites in ChA was close to the diameter of nanotubes (D ~10 nm), which shows the absence of crystal structure correlations. The XRD pattern of mesoporous silica filled by MBI does not exhibit reflections caused by MBI and a presence of MBI was confirmed only by the analysis of correlation function. The incorporation of MBI molecules into matrices is observed through optical IR absorption spectroscopy (FTIR) and photoluminescence. Introducing MBI in ChA and MS is followed by the appearance of bright green photoluminescence, the spectral structure of which is analogous to MBI crystals but slightly shifted in the blue region, probably due to a quantum-size effect. The influence of MBI inclusion in PG and ChA on the permittivity, dielectric losses, conductivity, and parameters of their hopping conductivity is analyzed.

Generating human neural diversity with a multiplexed morphogen screen in organoids.

Morphogens choreograph the generation of remarkable cellular diversity in the developing nervous system. Differentiation of stem cells toward particular neural cell fates in vitro often relies upon combinatorial modulation of these signaling pathways. However, the lack of a systematic approach to understand morphogen-directed differentiation has precluded the generation of many neural cell populations, and knowledge of the general principles of regional specification remain in-complete. Here, we developed an arrayed screen of 14 morphogen modulators in human neural organoids cultured for over 70 days. Leveraging advances in multiplexed RNA sequencing technology and annotated single cell references of the human fetal brain we discovered that this screening approach generated considerable regional and cell type diversity across the neural axis. By deconvoluting morphogen-cell type relationships, we extracted design principles of brain region specification, including critical morphogen timing windows and combinatorics yielding an array of neurons with distinct neuro-transmitter identities. Tuning GABAergic neural subtype diversity unexpectedly led to the derivation of primate-specific interneurons. Taken together, this serves as a platform towards an in vitro morphogen atlas of human neural cell differentiation that will bring insights into human development, evolution, and disease.

Mixture of an ionic liquid and organic solvent at graphene: interface structure and ORR mechanism.

Aprotic lithium-oxygen batteries are attracting the attention of the scientific community due to their outstanding theoretical performance, which, however, still has not been achieved in practice. One of the promising directions for improving the stability of Li-O2 batteries is electrolyte design, which would provide good cyclability, inhibition of parasitic processes, and high energy density. In recent years, there has been progress in the use of ionic liquids in the composition of the electrolyte. The present work reveals possible explanations of the influence of the ionic liquid on the mechanism of the oxygen reduction reaction by the example of a combined electrolyte from an organic solvent DME and an ionic liquid Pyr14TFSI. Molecular dynamics modelling of the interface between a graphene electrode and an organic solvent DME with a variable volume fraction of the ionic liquid shows the influence of the electrolyte structure at the interface to the kinetics on the adsorption and desorption stages of oxygen reduction reaction reactants. The obtained results suggest the promotion of a two-electron oxygen reduction reaction mechanism through the formation of solvated O22-, which may explain the reduced recharge overpotential reported in experiments.

Toward On-Chip Multisensor Arrays for Selective Methanol and Ethanol Detection at Room Temperature: Capitalizing the Graphene Carbonylation.

The artificial olfaction units (or e-noses) capable of room-temperature operation are highly demanded to meet the requests of society in numerous vital applications and developing Internet-of-Things. Derivatized 2D crystals are considered as sensing elements of choice in this regard, unlocking the potential of the advanced e-nose technologies limited by the current semiconductor technologies. Herein, we consider fabrication and gas-sensing properties of On-chip multisensor arrays based on a hole-matrixed carbonylated (C-ny) graphene film with a gradually changed thickness and concentration of ketone groups of up to 12.5 at.%. The enhanced chemiresistive response of C-ny graphene toward methanol and ethanol, of hundred ppm concentration when mixing with air to match permissible exposure OSHA limits, at room-temperature operation is signified. Following thorough characterization via core-level techniques and density functional theory, the predominant role of the C-ny graphene-perforated structure and abundance of ketone groups in advancing the chemiresistive effect is established. Advancing practice applications, selective discrimination of the studied alcohols is approached by linear discriminant analysis employing a multisensor array's vector signal, and the fabricated chip's long-term performance is shown.

Crystal Structure, Raman, FTIR, UV-Vis Absorption, Photoluminescence Spectroscopy, TG-DSC and Dielectric Properties of New Semiorganic Crystals of 2-Methylbenzimidazolium Perchlorate.

Single crystals of 2-methylbenzimidazolium perchlorate were prepared for the first time with a slow evaporation method from an aqueous solution of a mixture of 2-methylbenzimidazole (MBI) crystals and perchloric acid HClO4. The crystal structure was determined by single crystal X-ray diffraction (XRD) and confirmed by XRD of powder. Angle-resolved polarized Raman and Fourier-transform infrared (FTIR) absorption spectra of crystals consist of lines caused by molecular vibrations in MBI molecule and ClO4- tetrahedron in the region ν = 200-3500 cm-1 and lattice vibrations in the region of 0-200 cm-1. Both XRD and Raman spectroscopy show a protonation of MBI molecule in the crystal. An analysis of ultraviolet-visible (UV-Vis) absorption spectra gives an estimation of an optical gap Eg~3.9 eV in the crystals studied. Photoluminescence spectra of MBI-perchlorate crystals consist of a number of overlapping bands with the main maximum at Ephoton ≅ 2.0 eV. Thermogravimetry-differential scanning calorimetry (TG-DSC) revealed the presence of two first-order phase transitions with different temperature hysteresis at temperatures above room temperature. The higher temperature transition corresponds to the melting temperature. Both phase transitions are accompanied by a strong increase in the permittivity and conductivity, especially during melting, which is similar to the effect of an ionic liquid.

Correction: Modulation of the kinetics of outer-sphere electron transfer at graphene by a metal substrate.

Correction for 'Modulation of the kinetics of outer-sphere electron transfer at graphene by a metal substrate' by Sergey V. Pavlov et al., Phys. Chem. Chem. Phys., 2022, 24, 25203-25213, https://doi.org/10.1039/D2CP03771H.

Healing features of experimental injuries of soft tissues that contain foreign bodies in the form of fragments of military personnel uniforms.

INTRODUCTION: The healing of combat wounds can be complicated by the presence of foreign bodies. The present research aimed to study the regeneration of soft tissue injuries complicated by foreign bodies in the form of fragments of military uniforms. METHODS: 60 rats were divided into four groups: intact (Int), control (Con) and two experimental (EG1, EG2). In Con, wounds were sutured without implantation of foreign bodies. A uniform consisting of 100% cotton was used as foreign bodies for EG1 and a uniform consisting of 65% cotton and 35% polyester for EG2. Histological studies were performed according to generally accepted methods. The growth factors wеre determined by ELISA. RESULTS: In EG1, the inflammatory reaction proceeded protractedly, which complicated the development of granulation tissue. In EG2, considering the moderate inflammatory reactions, healing of the wounds became possible. The increase of the growth factors content in Con was maximal at the 15th day: basic fibroblast growth factor (bFGF)-2.2 times and vascular endothelial growth factor (VEGF)-1.6 times (p<0.001). In experimental groups, the bFGF content was maximal at the 60th day and exceeded the normal values by 1.7 times in EG1 and by 2.6 times in EG2 (p<0.001); the level of VEGF was slightly higher than that in healthy animals. CONCLUSIONS: The study showed wound healing in all groups. The repair of injuries in rats of EG1 and EG2 was complicated by the textile implant and took longer. The dynamics of the content of growth factors reflected the impairment of wound healing processes. These violations were more pronounced in the EG1 group.

Modulation of the kinetics of outer-sphere electron transfer at graphene by a metal substrate.

Solid-supported graphene is a typical configuration of electrochemical devices based on single-layer graphene. Therefore, it is necessary to understand the electrochemical features of such heterostructures. In this work, we theoretically investigated the effect of the metal type on the nonadiabatic electron transfer (ET) at the metal-supported graphene using DFT calculations. We considered five metals Au, Ag, Pt, Cu, and Al on which graphene is physically adsorbed. It is shown that all metals catalyze the ET. The electrocatalytic effect increases in the following series Al < Au ≲ Ag ≈ Cu < Pt. The enhanced ET in the presence of the metal substrate is explained by the hybridization of metal and graphene states, due to which the coupling between the reactant in an electrolyte and metal is increased. Metal-dependent electrocatalytic effect is explained both by different densities of states at the Fermi level of the systems and by differences in the behaviour of the tails of hybridized wave functions in the electrolyte region. The shift of the Fermi level with respect to the Dirac point in graphene when charging at the metal/graphene/electrolyte interface does not affect the kinetics due to the small contribution of graphene states to the electron transfer.

Effect of LIBS-Induced Alteration on Subsequent Raman Analysis of Iron Sulfides.

Mineral alteration is a possible side effect of spectroscopic techniques involving laser ablation, such as laser-induced breakdown spectroscopy (LIBS), and is related to the interaction of the generated plasma and ablated material with samples, dust, or ambient atmosphere. Therefore, it is essential to understand these interactions for analytical techniques involving laser ablation, especially for space research. In this combined LIBS-Raman analytical study, pyrite (FeS2) and pyrrhotite (Fe1-x S) samples have been consecutively measured with LIBS and Raman spectroscopy, under three different atmospheric conditions: ∼10-4 mbar (atmosphereless body), ∼7 mbar, and Martian atmospheric composition (Martian surface conditions), and 1 bar and Martian atmospheric composition. Furthermore, a dust layer was simulated using ZnO powder in a separate test and applied to pyrite under Martian atmospheric conditions. In all cases, Raman spectra were obscured after the use of LIBS in the area of and around the formed crater. Additional Raman transitions were detected, associated with sulfur (pyrite, 7.0 mbar and 1.0 bar), polysulfides (all conditions), and magnetite (both minerals, 1.0 bar). Magnetite and polysulfides formed a thin film of up to 350-420 and 70-400 nm in the outer part of the LIBS crater, respectively. The ZnO-dust test led to the removal of the dust layer, with a similar alteration to the nondust pyrite test at 7.0 mbar. The tests indicate that recombination with the CO2-rich atmosphere is significant at least for pressures from 1.0 bar and that plasma-dust interaction is insignificant. The formation of sulfur and polysulfides indicates fractionation and possible loss of volatile elements caused by the heat of the LIBS laser. This should be taken into account when interpreting combined LIBS-Raman analyses of minerals containing volatile elements on planetary surfaces.

Features of cellular and molecular mechanisms of re-gulation of reparative processes in chronic wounds using photobiomodulation therapy.

INTRODUCTION: Treatment of chronic wounds is an urgent worldwide problem for medicine. Among the many efforts in wound healing techniques, photobiomodulation therapy has shown promising results.

The effect of a mixture of an ionic liquid and organic solvent on oxygen reduction reaction kinetics.

Li-O2 batteries attract great attention due to their promising theoretical energy density. One of the main obstacles on the way to achieving high energy density and good cyclability is positive electrode passivation by the Li2O2 discharge product as well as the presence of parasitic reactions that degrade electrode and electrolyte materials. To overcome these issues new electrolytes are being extensively searched for to ensure the bulk-mediated mechanism of the oxygen reduction reaction and inhibition of parasitic reactions. Different additives to organic solvents can significantly change the properties of electrolytes. This work is devoted to the effect of ionic liquids (ILs), which are proposed as an additive to the solvent due to their excellent solvation properties, high stability, low volatility and flammability. Using molecular dynamics simulations we investigate mixtures of the Pyr14TFSI ionic liquid and dimethoxyethane (DME) with different volume fractions of the IL. Our calculations show that the presence of the ionic liquid in the electrolyte stabilises solvation shells around the ions, both involved in the oxygen reduction and parasitic reactions, slowing down the kinetics of Li+ and O2- association. This makes the usage of such mixtures promising for electrolyte design for Li-O2 batteries.

MECHANISMS OF THE FORMATION OF MOTOR-SECRETORY DISORDERS IN PATIENTS WITH GERD WITH CONCOMITANT AIT.

OBJECTIVE: The aim: The aim of this work was to study the effect of thyroid hormones on motor-secretory dysfunction in patients with GERD with concomitant AIT. PATIENTS AND METHODS: Materials and methods: The study involved three groups of patients: with isolated GERD, GERD with AIT at the stage of hypothyroidism and GERD with AIT at the stage of hyperthyroidism. The control group consisted of 15 practically healthy individuals. GERD and AIT were diagnosed on the basis of ICD-10. All patients underwent a comprehensive examination, including ultrasound examination of the motor-evacuation function of the esophagus and stomach. Quality of life of patients was assessed by using the GIQLI questionnaire. RESULTS: Results: The most expressed complaints and low quality of life are observed among patients with combined pathology. The results of pH-metry indicate more severe course of GERD among patients with concomitant AIT. The most pronounced decrease in the tone of the lower esophageal sphincter and increased regurgitation were observed in the second group. CONCLUSION: Conclusions: 1. It was found that more reliable motor-secretory disorders were observed among patients with GERD with concomitant AIT. 2. A close correlation was established between the severity of the clinical picture, the level of increased thyroid hormones and the degree of impairment of motor-secretory disorders among patients with GERD with concomitant AIT; 3. The results obtained indicate that changes in the metabolism of thyroid hormones are one of the factors involved in the mechanisms of GERD formation.

PROGNOSTIC SIGNIFICANCE OF METABOLISM INDICATORS OF CONNECTIVE TISSUE IN PATIENTS WITH UPPER URINARY TRACT OBSTRUCTION.

OBJECTIVE: The aim: The aim of the study was a comparative analysis of indicators characterizing the state of connective tissue in patients with hydronephrosis due to upper urinary tract obstruction, with the presence and absence of recurrence after surgery. PATIENTS AND METHODS: Materials and methods: Levels of free and bound hydroxyproline, as well as the key mediator of fibrogenesis transforming growth factor-ß1 in serum of patients with congenital and acquired obstructions were determined. Ratio peptide-bound and free hydroxyproline were calculated. Groups were divided according to the presence or absence of recurrence of the stricture for a period of 4.5 years after surgery. RESULTS: Results: Imbalance of the destructive and synthetic processes in extracellular matrix of connective tissue that is characterized by a higher content of fractions of hydroxyproline and transforming growth factor-ß1 in the serum were identified. It is shown that the most pronounced changes are observed in patients with relapsing. In patients with a congenital obstruction and a recurrent course of the disease, the highest activation of the collagen metabolism was observed, which was evidenced by the high levels peptide-bound and protein-bound hydroxyproline, relative to these indicators in patients with acquired obstruction (as with the presence and absence of relapses). CONCLUSION: Conclusions: The increase in the ratio of peptide-bound/free hydroxyproline and the level of transforming growth factor-ß1 in the blood of patients with stage II-III hydronephrosis on the 21st day after surgery may be a prognostic marker for the development of disease recurrence.

Manifesting Epoxide and Hydroxyl Groups in XPS Spectra and Valence Band of Graphene Derivatives.

The derivatization of graphene to engineer its band structure is a subject of significant attention nowadays, extending the frames of graphene material applications in the fields of catalysis, sensing, and energy harvesting. Yet, the accurate identification of a certain group and its effect on graphene's electronic structure is an intricate question. Herein, we propose the advanced fingerprinting of the epoxide and hydroxyl groups on the graphene layers via core-level methods and reveal the modification of their valence band (VB) upon the introduction of these oxygen functionalities. The distinctive contribution of epoxide and hydroxyl groups to the C 1s X-ray photoelectron spectra was indicated experimentally, allowing the quantitative characterization of each group, not just their sum. The appearance of a set of localized states in graphene's VB related to the molecular orbitals of the introduced functionalities was signified both experimentally and theoretically. Applying the density functional theory calculations, the impact of the localized states corresponding to the molecular orbitals of the hydroxyl and epoxide groups was decomposed. Altogether, these findings unveiled the particular contribution of the epoxide and hydroxyl groups to the core-level spectra and band structure of graphene derivatives, advancing graphene functionalization as a tool to engineer its physical properties.

The influence of foreign textile bodies from military clothes on the healing process of experimental injuries of soft tissues.

Background: The healing of combat wounds can be complicated by the presence of foreign bodies, including fragments of military clothing. The present work aims to study the morphological features of soft tissue injuries with textile fibers implanted into wounds, personnel military forms during wound healing, in the experiment. Methods: By randomization, 54 rats were divided into 3 groups. Control group animals performed a layer-by-layer incision of soft tissues without implantation of foreign bodies. Animals of the experimental group 1 were made implantation of fibers of a fabric consisting of 100% cotton, and of the experimental group 2-of fibers of a fabric consisting of 65% cotton and 35% polyester. Removal of laboratory animals from the experiment was carried out on the 15th, 30th, and 60th day. Soft tissue samples were histologically examined. Results: The least pronounced inflammation was observed in rats of the control group. Wound healing in the experimental groups was slowed down due to the presence of inflammatory foci. A more pronounced inflammatory reaction was characterized by a group of animals with implanted tissue fibers consisting of 100% cotton. In the group with implanted tissue fibers consisting of 65% cotton and 35% polyester, the inflammatory reactions were less pronounced. Conclusions: The presence of textile foreign bodies hampers the healing process of wounds of soft tissues due to the developing processes of inflammation around foreign bodies. The uniform of servicemen (35% synthetic and 65% natural fiber) is less reactive, leaving a wound as a textile foreign body, and has a less pronounced inflammatory effect, apparently due to the presence of synthetic threads that are more inert compared to fabric containing 100% natural fiber. This confirms the need for thorough debridement of combat wounds during the primary surgical treatment.

Nonmonotonous temperature dependence of Shapiro steps in YBCO grain boundary junctions.

The amplitudes of the first Shapiro steps for an external signal with frequencies of 72 and 265 GHz are measured as function of the temperature from 20 to 80 K for a 6 µm Josephson grain boundary junction fabricated by YBaCuO film deposition on an yttria-stabilized zirconia bicrystal substrate. Non-monotonic dependences of step heights for different external signal frequencies were found in the limit of a weak driving signal, with the maxima occurring at different points as function of the temperature. The step heights are in agreement with the calculations based on the resistively-capacitively shunted junction model and Bessel theory. The emergence of the receiving optima is explained by the mutual influence of the varying critical current and the characteristic frequency.