Случай первичной солитарной плазмоцитомы трахеи

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Mechanism of interaction among nanocrystalline carbonate-substituted hydroxyapatite and polar amino-acids for the biomimetic composite technology: Spectroscopic and structural study

This study investigated changes in the interaction of B-type non-stoichiometric nanocrystalline carbonate-substituted hydroxyapatite (nano-CHAP) with polar amino acids (AA) with respect to CHAP-AA linking. Molecular vibrational spectroscopy revealed for the first time that the surface interaction of polar amino acids with defective nano-CHAP is determined not only by the charge state of AA but can be mediated by a foreign ion conjugated with the lateral bonds of amino acids. Understanding this mechanism of CHAP-AA interaction is required for the development of the new generation of dental biomimetic materials based on HAP as well as for their qualitative integration with the amino acid matrix of the dental tissues. © 2020Russian Foundation for Basic Research, RFBR: MK-419.2019.2, 18-29-11008The study was performed under support of Russian Foundation for Basic Research (RFBR) grant №18-29-11008 mk and grant of the President of Russian Federation №MK-419.2019.2

XANES Investigation of the Influence of a Coordinating Atomic Environment in Biomimetic Composite Materials

In our work, the influence of the coordination environment of the Ca atom states in biomimetic mineralizing composite dental materials integrated with dental tissue was investigated. Biomimetic composites as well as natural dental tissue samples were investigated using synchrotron X-ray absorption near edge structure (XANES) spectroscopy. Energy structure studies revealed a number of important features related to the different type of calcium atom environment. the surface of nanocrystalline calcium carbonate-substituted hydroxyapatite (nano-cHAp) crystals in natural enamel and dentin involved in the formation of bonds with the organic matrix is more characterized by the coordination environment of the calcium atom corresponding to its location in the CaI position, i.e. bound through common oxygen atoms with PO4 tetrahedrons. At the same time, on the surface of nano-cHAp crystals in bioinspired dental materials, the calcium atom is more characteristically located in the CaII position, bound to the hydroxyl OH group. The detected features in the coordination atomic environment in nano-cHAp play a fundamental role for engineering a biomimetic dental composite of the natural organomineral interaction in the mineralized tissue. © 2022 The Authors.This work was funded by the grant of Russian Science Foundation, grant number 21-75-10005. The access to scientific equipment and methodology was provided under support of the Ministry of Science and Higher Education of Russia, Agreement N 075-15-2021-1351

The Molecular and Mechanical Characteristics of Biomimetic Composite Dental Materials Composed of Nanocrystalline Hydroxyapatite and Light-Cured Adhesive

The application of biomimetic strategies and nanotechnologies (nanodentology) has led to numerous innovations and provided a considerable impetus by creating a new class of modern adhesion restoration materials, including different nanofillers. An analysis of the molecular properties of biomimetic adhesives was performed in this work to find the optimal composition that provides high polymerisation and mechanical hardness. Nanocrystalline carbonate-substituted calcium hydroxyapatite (nano-cHAp) was used as the filler of the light-cured adhesive Bis-GMA (bisphenol A-glycidyl methacrylate). The characteristics of this substance correspond to the apatite of human enamel and dentin, as well as to the biogenic source of calcium: avian eggshells. The introduction and distribution of nano-cHAp fillers in the adhesive matrix resulted in changes in chemical bonding, which were observed using Fourier transform infrared (FTIR) spectroscopy. As a result of the chemical bonding, the Vickers hardness (VH) and the degree of conversion under photopolymerisation of the nano-cHAp/Bis-GMA adhesive increased for the specified concentration of nanofiller. This result could contribute to the application of the developed biomimetic adhesives and the clinical success of restorations. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.075-15-2021-1351; Russian Science Foundation, RSF: 21-15-00026This work was funded by the grant of the Russian Science Foundation, grant number 21-15-00026. The access to scientific equipment and methodology was provided under the support of the Ministry of Science and Higher Education of Russia, Agreement No. 075-15-2021-1351

HRXRD study of the effect of a nanoporous silicon layer on the epitaxial growth quality of GaN layer on the templates of SiC/por-Si/c-Si

Using High Resolution X-ray Diffraction (HRXRD) diagnostic techniques the influence of the transition layer of nanoporous silicon on the practical implementation and certain features of the epitaxial growth of GaN layers with the use of molecular beam epitaxy were investigated by means of plasma activation of nitrogen (MBE PA) on the templates of SiC/por-Si/c-Si. For the first time it was shown that introducing of the transition layer of nanoporous silicon in the template of SiC/por-Si/c-Si where the layer of 3C-SiC was obtained by substitution of the atoms had a number of indisputable advantages as compared with conventional silicon substrates. Particularly, such an approach, in fact, enabled a 90% reduction in the level of stresses in the crystalline lattice of the epitaxial GaN layer which was synthesized on SiC surface of SiC/por-Si/c-Si template by means of MBE PA technique as well as to decrease some of vertical dislocations within GaN layer. © 2020 The AuthorsRussian Science Foundation, RSFThe work was executed under support of the grant of Russian Science Foundation 19-72-10007 . Access to KNMF equipment was obtained under the grant of the President of the Russian Federation MD-42.2019.2

Effect of Exo/Endogenous Prophylaxis Dentifrice/Drug and Cariogenic Conditions of Patient on Molecular Property of Dental Biofilm: Synchrotron FTIR Spectroscopic Study

(1) Objectives: This study is the first one to investigate the molecular composition of the dental biofilm during the exogenous and endogenous prophylaxis stages (use of dentifrice/drug) of individuals with different cariogenic conditions using molecular spectroscopy methods. (2) Materials and Methods: The study involved 100 participants (50 males and 50 females), aged 18–25 years with different caries conditions. Biofilm samples were collected from the teeth surface of all participants. The molecular composition of biofilms was investigated using synchrotron infrared microspectroscopy. Changes in the molecular composition were studied through calculation and analysis of ratios between organic and mineral components of biofilm samples. (3) Results: Based on the data obtained by synchrotron FTIR, calculations of organic and mineral component ratios, and statistical analysis of the data, we were able to assess changes occurring in the molecular composition of the dental biofilm. Variations in the phosphate/protein/lipid, phosphate/mineral, and phospholipid/lipid ratios and the presence of statistically significant intra-and inter-group differences in these ratios indicate that the mechanisms of ion adsorption, compounds and complexes arriving from oral fluid into dental biofilm during exo/endogenous prophylaxis, differ for patients in norm and caries development. (4) Conclusions: The conformational environment and charge interaction in the microbiota and the electrostatic state of the biofilm protein network in patients with different cariogenic conditions play an important role. (5) Clinical Significance: Understanding the changes that occur in the molecular composition of the dental biofilm in different oral homeostasis conditions will enable successful transition to a personalised approach in dentistry and high-tech healthcare. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.Russian Science Foundation, RSF: 21-15-00026; Ministry of Science and Higher Education of the Russian Federation: N 075-15-2021-1351This work was funded by the grant of Russian Science Foundation, grant number 21-15-00026. The access to scientific equipment and methodology was provided under support of the Ministry of Science and Higher Education of Russia, Agreement N 075-15-2021-1351

Development of a Visualisation Approach for Analysing Incipient and Clinically Unrecorded Enamel Fissure Caries Using Laser-Induced Contrast Imaging, MicroRaman Spectroscopy and Biomimetic Composites: A Pilot Study

This pilot study presents a practical approach to detecting and visualising the initial forms of caries that are not clinically registered. The use of a laser-induced contrast visualisation (LICV) technique was shown to provide detection of the originating caries based on the separation of emissions from sound tissue, areas with destroyed tissue and regions of bacterial invasion. Adding microRaman spectroscopy to the measuring system enables reliable detection of the transformation of the organic–mineral component in the dental tissue and the spread of bacterial microflora in the affected region. Further laboratory and clinical studies of the comprehensive use of LICV and microRaman spectroscopy enable data extension on the application of this approach for accurate determination of the boundaries in the changed dental tissue as a result of initial caries. The obtained data has the potential to develop an effective preventive medical diagnostic approach and as a result, further personalised medical treatment can be specified. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.Russian Science Foundation, RSF: 21-15-00026; Ministry of Science and Higher Education of the Russian Federation: N 075-15-2021-1351Funding: This work was funded by a grant from the Russian Science Foundation, grant number 21-15-00026. The access to scientific equipment and methodology was provided under support from the Ministry of Science and Higher Education of Russia, agreement N 075-15-2021-1351

Raman and XANES Spectroscopic Study of the Influence of Coordination Atomic and Molecular Environments in Biomimetic Composite Materials Integrated with Dental Tissue

In this work, for the first time, the influence of the coordination environment as well as Ca and P atomic states on biomimetic composites integrated with dental tissue was investigated. Bioinspired dental composites were synthesised based on nanocrystalline calcium carbonate-substituted hydroxyap-atite (Formula presented) (nano-cHAp) obtained from a biogenic source and a set of po-lar amino acids that modelled the organic matrix. Biomimetic composites, as well as natural dental tissue samples, were investigated using Raman spectromicroscopy and synchrotron X-ray absorption near edge structure (XANES) spectroscopy. Molecular structure and energy structure studies revealed several important features related to the different calcium atomic environments. It was shown that biomimetic composites created in order to reproduce the physicochemical properties of dental tissue provide good imitation of molecular and electron energetic properties, including the carbonate anion CO32− and the atomic Ca/P ratio in nanocrystals. The features of the molecular structure of biomimetic composites are inherited from the nano-cHAp (to a greater extent) and the amino acid cocktail used for their creation, and are caused by the ratio between the mineral and organic components, which is similar to the composition of natural enamel and dentine. In this case, violation of the nano-cHAp stoichiometry, which is the mineral basis of the natural and bioinspired composites, as well as the inclusion of different molecular groups in the nano-cHAp lattice, do not affect the coordination environment of phosphorus atoms. The differences observed in the molecular and electron energetic structures of the natural enamel and dentine and the imitation of their properties by biomimetic materials are caused by rearrangement in the local environment of the calcium atoms in the HAp crystal lattice. The surface of the nano-cHAp crystals in the natural enamel and dentine involved in the formation of bonds with the organic matrix is character-ised by the coordination environment of the calcium atom, corresponding to its location in the CaI posi-tion—that is, bound through common oxygen atoms with PO4 tetrahedrons. At the same time, on the surface of nano-cHAp crystals in bioinspired dental materials, the calcium atom is characteristically lo-cated in the CaII position, bound to the hydroxyl OH group. The features detected in the atomic and molecular coordination environment in nano-cHAp play a fundamental role in recreating a biomimetic dental composite of the natural organomineral interaction in mineralised tissue and will help to find an optimal way to integrate the dental biocomposite with natural tissue. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.This work was supported by a grant from the Russian Science Foundation, grant number 21-75-10005; The access to scientific equipment and methodology was provided under support of the Ministry of Science and Higher Education of Russia, Agreement N 075-15-2021-1351

Engineering of biomimetic mineralized layer formed on the surface of natural dental enamel

The problem of engineering a biomimetic mineralized layer on the surface of native dental tissue (bio-template) was considered in our work. The formation of the mineralized layer on a biotemplate is achieved with the use of nanocrystalline carbonate-substituted calcium hydroxyapatite (HAp), calcium alkali, and a complex of polyfunctional organic and polar amino acids. By applying the set of structural and spectroscopic methods of analysis we have confirmed the formation of a mineralized biomimetic HAp layer on the surface of bio-template with properties resembling those of natural hard tissue. The thickness of the biomimetic mineralized layer varies from 300 to 500 nm, while the direction of some ncHAp nanocrystals coincides with that of the apatite crystals in the enamel. We also demonstrated that the engineered mineralized HAp layer was characterized by homogeneous micromorphology and enhanced nanohardness in the region of the enamel rods exceeding those of native enamel. The development of a strategy for biomimetic engineering and a technique for enamel surface pre-treatment to enable tissue mineralization has huge potential in dental applications. © 2022 The AuthorsRussian Science Foundation, RSF: 21-75-10005; Ministry of Science and Higher Education of the Russian Federation: N 075-15-2021-1351This work was funded by the Russian Science Foundation , grant number 21-75-10005 ;The access to scientific equipment and methodology was provided under support of the Ministry of Science and Higher Education of Russia, Agreement N 075-15-2021-1351

Bound oxygen influence on the phase composition and electrical properties of semi-insulating silicon films

The purpose of this work is to establish of the bound oxygen effect on the phase composition of the Semi-Insulating Polycrystalline Oxygen-doped Silicon (SIPOS) films by means of three independent methods: X-ray diffraction (XRD), Ultrasoft X-ray Emission Spectroscopy (USXES) and Raman spectroscopy, also on their electrophysical properties, depending on the relative oxygen content in the gas mixture flow (γ=N2O/SiH4) of the plasma reactor during the chemical vapor deposition of submicron SIPOS layers on monocrystalline silicon wafers. The increase in the oxygen content in SIPOS layers from γ=0 to maximum at γ=0.15 leads to the reduction of Si nanocrystals size from ~75 nm to 2–5 nm, submerged in amorphous matrix. Oxygen is contained in the bound form of silicon-oxygen clusters SiOSi3 type in the amorphous silicon matrix without SiO2 formation. These nonlinear qualitative and quantitative changes in the atomic structure of the SIPOS layers under the influence of bound oxygen increase not only the resistivity of the films by two orders of magnitude but also the activation energy of conductivity in comparison with silicon at the temperatures above room temperature. © 2020 Elsevier LtdRussian Foundation for Basic Research, RFBR: 19-42-363013MD-42.2019.2Ministry of Science and Higher Education of the Russian FederationThe reported study was funded by RFBR and Government of Voronezh region according to the research project № 19-42-363013.The part of work was carried out with the support of the Ministry of Science and Higher Education of Russia Federation under the grand No. FZGU-2020-0036 .In part of diagnostics of the structures the work of P.V. Seredin was supported by the RF President's Grants Council (Grant MD-42.2019.2)