Stage Of Synthesis Research Articles

Room‐temperature mechanochemical synthesis of RE molybdates: Impact of structural similarity and basicity of oxides

AbstractThe feasibility of room‐temperature synthesis of R10Mo2O21 (R = La, Y, Er) molybdates via mechanochemical processing of the 5R2O3+2MoO3 oxide mixtures has been studied using X‐ray powder diffraction (XRD) with Rietveld refinement and electron spin resonance spectroscopy (ESR). In all systems, the initial stage of mechanochemical synthesis is associated with MoO3 dissolution in R2O3 despite the difference in the crystal structure of initial oxides: La2O3 (, no. 164), Er2O3 and Y2O3 (, no. 206). Only for the 5Er2O3 + 2MoO3 system containing magnetic cations, ESR detects A‐type Mo5+ centers, thus enabling to follow the decrease in MoO3 content during room‐temperature mechanochemical synthesis. In the Er‐ and Y‐based systems, the starting oxides and synthesized R10Mo2O21 (R = Y, Er) molybdates have the same bixbyite structure and mechanochemical MoO3 dissolution in these oxides leads to R10Mo2O21 synthesis at room temperature within 80 min. In the La‐based system, MoO3 dissolution leads mainly to mechanochemical synthesis of La10Mo2O21 with the same structure as the starting La2O3 (, no. 164), but the amorphization of La2O3 and formation of basic lanthanum hydroxide during milling also took place. The use of nanosized MoO3 facilitates the slightly formation of La10Mo2O21 (, no. 164), but makes no impact on the synthesis of La10Mo2O21 ( (RI), no. 166).

RIOK2 phosphorylation by RSK promotes synthesis of the human small ribosomal subunit.

Ribosome biogenesis lies at the nexus of various signaling pathways coordinating protein synthesis with cell growth and proliferation. This process is regulated by well-described transcriptional mechanisms, but a growing body of evidence indicates that other levels of regulation exist. Here we show that the Ras/mitogen-activated protein kinase (MAPK) pathway stimulates post-transcriptional stages of human ribosome synthesis. We identify RIOK2, a pre-40S particle assembly factor, as a new target of the MAPK-activated kinase RSK. RIOK2 phosphorylation by RSK stimulates cytoplasmic maturation of late pre-40S particles, which is required for optimal protein synthesis and cell proliferation. RIOK2 phosphorylation facilitates its release from pre-40S particles and its nuclear re-import, prior to completion of small ribosomal subunits. Our results bring a detailed mechanistic link between the Ras/MAPK pathway and the maturation of human pre-40S particles, which opens a hitherto poorly explored area of ribosome biogenesis.

KERUSAKAN LINGKUNGAN AKIBAT PEMBANGUNAN INFRASTRUKTUR

The purpose of making this final work of graphic art is to visualize forms of environmental damage due to infrastructure development with serigraphy techniques and also to create working techniques in graphic arts and to deepen the concept of work. The stages used in this final work are the stages of preparation, elaboration, synthesis, concept realization and completion stages. So that ten works were created that visualize the form of environmental damage due to infrastructure development with the following titles: the first work is "Pencemaran Laut", the second is "Terdesak", the third is "Tak Sesuai Kenyataan", the fourth is "Hilang Asa", the fifth is "Korban Infrastruktur", sixth " Terkikis Habis ", seventh" Dampak Pencemaran Udara ", eighth" Kehilangan Habitat ", ninth" Berangan-angan "and ten" Pemukiman Diatas Banjir ".Kata Kunci: Kerusakan Lingkungan, Infrastruktur, Seni Grafis

BURUNG WALET DALAM KARYA SENI GRAFIS

The making of the final work of graphic art using serigraphy techniques is to visualize the uniqueness of the swallow, including its characters and anatomy. Several stages were taken in carrying out this final work including preparation, elaboration, synthesis, concept realization and completion stages. By carrying out these stages, ten graphic art works visualizing the various uniqueness of the swallow birds, including the titles "Tersesat", "Straight", Doubt "," Group ".Kata Kunci: Burung Walet, Keunikan, Seni Grafis.

Modification of nanoclay with different methods and its application in urea-formaldehyde bonded plywood panels

ABSTRACT The reinforcement of pristine nanoclay (PNC) and modified nanoclay (MNC) in urea-formaldehyde (UF) resins at the alkaline stage of synthesis was investigated in this work. The modification of PNC using copper (II) chloride (CuCl2) as transition metal ions was carried by three different modification methods that were coded as Cu-MNC (25, 36), Cu-MNC (60, 6), and Cu-MNC (80, 3), respectively. The modification of PNC was characterized by X-ray diffraction, showing the increased d-spacing after the modification. The reinforcement of 5 wt% of PNC and Cu-MNC at the alkaline reaction of UF resins that were coded as UF/PNC, UF/MNC (25, 36), UF/MNC (60, 6), and UF/MNC (80, 3). The X-ray diffraction study showed that the addition of PNC and Cu-MNC into the UF resins decreased the crystallinity of resins from 48.1% to 45% for UF/PNC and 25% for all UF/MNC. The curing behavior exhibited that the activation energy of UF resins decreased with addition of PNC and Cu-MNC. The loading of PNC and Cu-MNC into UF resins improved the adhesion and reduced the formaldehyde emission of UF resins in plywood. Statistical analysis suggested that UF/MNC (80, 3) produced plywood with greater adhesion strength and lower formaldehyde emission over other modified resins.

Abstract P-35: Cryo-Electron Tomography of Protein Conjugated Upconverting Nanophosphors

Background: Over the past decades, significant advances have been made in the field of creating nanobioreagents for solving modern medicine problems (Grebenik et al., JBO, 2013). However, the problem of their low accumulation rate in pathological tissue in vivo experiments still remains. First of all, it is associated with the adsorption of blood proteins on the surface of nanobioreagents and the protein layer formation, which significantly changes the surface properties, which leads to their rapid excretion by the reticuloendothelial system. In particular, it is possible to reduce the blood plasma proteins adsorption and increase the time spent in the circulatory system by forming a coating of proteins. Methods: In situ cryоelectron tomography (Cryo-ET) is the only method that allows the experimental observation of protein structures on the nanoparticle’s surface in their natural functional state. The basic principle of the method is to obtain a series of projections of a vitrified sample thin lamella at different tilt angles related to an incident electron beam. Their further processing leads to obtaining the volumetric information about the structure of the sample. The use of a cryo-focused ion beam (Cryo-FIB) in specimen thinning makes it possible to carry out experiments with thin sections of cellular structures and observe the penetration of nanoparticles into the intracellular environment. Results: Upconverting nanophosphors (AN) were used as a nanoplatform for creating a protein coating. To create a protein coating on the AN surface, they were functionalized using an amphiphilic polymer containing carboxyl groups. Then, conjugation with protein molecules from the class of immunoglobulins was carried out by the method of carbodiimide activation. At each stage of synthesis and modification, AN solutions with different size distribution were vitrified for subsequent tomography. After a series of experiments to study the morphology of nanoparticles, an experiment on their successful absorption by cells of the cancer line A549 was carried out. Conclusion: Within this work, a series of in situ Cryo-ET methods were proposed and applied for structural characterization and visualization of the processes of synthesis, modification, and engulfment of nanoparticles into cellular systems. For the first time in its native form, the engulfment of ANF into the internal environment of the A549 cancer line cells was demonstrated.

A multifactorial proteomics approach to sex‐specific effects of diet composition and social environment in an omnivorous insect

AbstractRearing conditions may elicit noticeable plastic responses in life‐history traits of living organisms. Diet composition and the social environment have proven to influence prominent traits such as survival, body size, fecundity, and life span. Nevertheless, the physiological mechanisms underlying such responses are largely unknown. In this study, we investigated changes in the proteome of the house cricketAcheta domesticussubjected to diets of different nutritional composition (i.e., protein to carbohydrates ratio) and two distinct social environments (i.e., solitary or in groups). We measured the relative abundances of 685 proteins identified in whole‐body cricket samples using high‐performance liquid chromatography coupled to tandem mass spectrometry. Differential expression of proteins induced by diet composition and social environment in female and maleA. domesticuswas assessed in a data‐independent proteomics approach. Additionally, we performed a functional analysis of the differentially expressed proteins using comprehensive databases (KEGG and GO). We found that sex alone explained a significant portion (40.87%) of the relative protein abundance variation. Males had a higher representation of proteins involved in metabolic pathways and locomotion. In contrast, females exhibited a higher abundance of proteins related to genetic processes regulation and nutrient catabolism. Moreover, diet composition and social environment induced sex‐specific changes in a smaller set of proteins with particular roles. Females had their protein profile affected by diet composition and social environment. The involved proteins were mainly related to several protein synthesis stages, carbohydrate metabolism, and muscle development. In contrast, males were only affected by diet composition, overexpressing proteins related to hormone production, carbohydrate metabolism, and apparently depositing excess protein in the cuticle when fed with a protein‐rich diet. Evidently, diet had a more substantial influence on the proteome of the cricketA. domesticusthan the social environment, showing that diet composition may exert profound physiological changes in insects in a sex‐specific manner.

Первичная причина развития семядольного бактериоза у сои и других зернобобовых культур

One of the significant reasons for the decrease in the sowing quality of seeds in leguminous crops all over the world is bacterial blight of seeds in the form of necrotic decaying spots on the outer or inner side of the cotyledons. A hypothesis was put forward about the presence of a common primary non-bacterial cause of the development of necrosis on cotyledons, regardless of the species, variety and growing zone. The studies were carried out in 2016– 2020 in V.S. Pustovoit All-Russian Research Institute of Oil Crops, Krasnodar, on seeds of soybeans, common bean, chickpea, white and narrow-leaved lupines. On immature seeds of healthy soybean plants in the phases of full filling and the beginning of physiological maturation, bacterial blight of seeds are never observed. Secondary (rain) moistening of mature seeds leads to the development of cotyledon necrosis and a decrease in their germination in soybeans, common beans, chickpeas, white lupine and narrow-leaved lupine. The physiological reason for the formation of cotyledon necrosis during the secondary moistening of mature seeds is the death of the tissues of the cotyledons, moistened before the stage of nucleic acid synthesis, and unable to return to the dormant stage upon repeated drying. Symptoms of the development of cotyledon necrosis after secondary moistening of mature seeds, and bacterial blight of seeds, are practically identical in all leguminous crops. The common primary cause of the formation of necrotic spots on the surface of the cotyledons, identified as bacterial blight of seeds, regardless of the species of legumes, variety and ecological-geographical zone of cultivation, is the secondary (rain) moisture of seeds that have not yet been harvested in the field of mature plants. Isolation of bacterial pathogens of various species and families in necrotic areas of the cotyledons can be explained by secondary infection of already dead tissues. Therefore, the species composition of bacterial microflora in each case will be determined by its presence in the environment.

Discovery of Novel eEF2K Inhibitors Using HTS Fingerprint Generated from Predicted Profiling of Compound-Protein Interactions.

Background: Eukaryotic elongation factor 2 kinase (eEF2K) regulates the elongation stage of protein synthesis by phosphorylating eEF2, a process related to various diseases including cancer and cardiovascular and neurodegenerative diseases. In this study, we describe the identification of novel eEF2K inhibitors using high-throughput screening fingerprints (HTSFP) generated from predicted profiling of compound-protein interactions (CPIs). Methods: We utilized computationally generated HTSFPs referred to as chemical genomics-based fingerprint (CGBFP). Generally, HTSFPs are generated from multiple biochemical or cell-based assay data. On the other hand, CGBFPs are generated from computational prediction of CPIs using the Chemical Genomics-Based Virtual Screening (CGBVS) method. Therefore, CGBFPs do not have missing information mainly caused by the absence of assay data. Results: Chemogenomics-Based Similarity Profiling (CGBSP) of the screening library (2.6 million compounds) yielded 27 compounds which were evaluated for in vitro eEF2K inhibitory activity. Three compounds with interesting results were identified. Compounds 2 (IC = 11.05 μM) and 4 (IC = 43.54 μM) are thieno[2,3-b]pyridine derivatives that have the same scaffolds with a known eEF2K inhibitor, while compound 13 (IC = 70.13 μM) was a new thiophene-2-amine-type eEF2K inhibitor. Conclusions: CGBSP supplied an efficient strategy in the identification of novel eEF2K inhibitors and provided useful scaffolds for optimization.

Catalytic combustion of volatile organic compounds (VOCs) over structured Co3O4 nano-flowers on silicalite-1/SiC foam catalysts

This work presents a simple method for the preparation of structured Co3O4 supported on silicalite-1/SiC foam catalyst (i.e., [email protected]/SiC), and its application to catalytic combustion of volatile organic compounds (VOCs, isopropanol as the model compound). The growth mechanism of Co3O4 on silicalite-1/SiC catalysts were systematically studied as a function of synthesis time based on comprehensive characterization using N2 adsorption-desorption analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), H2 temperature programmed reduction (H2-TPR) and X-ray photoelectron spectra (XPS). It was found that Co2SiO4 nano-sheets were formed within/on silicalite-1 coating at the initial stage of synthesis, which was further transformed into flower-like Co3O4 nano crystals on the surface of silicalite-1/SiC. The developed structured catalyst, especially the one prepared by the 40 h synthesis, i.e., [email protected]/SiC-40 h, combined high oxygen mobility, Co3+/Co2+ redox couple and improved adsorbed oxygen species, and exhibited excellent performance in complete thermocatalytic combustion of isopropanol.

Analysis on leading-fiber-induced Doppler noise in interferometric FBG sensor arrays using polarization switching and PGC hybrid processing method.

The random disturbance in the leading fiber is considered as a vital noise source in the practical interferometric fiber Bragg grating (FBG) sensor array, which is usually interrogated by periodic laser pulse pair. As the two interrogation laser pluses propagate through the leading fiber in a time-sharing manner, the leading fiber disturbance could cause undesired demodulated phase noises to both the polarization state and the pulse-interval, which are summarized as the polarization fading induced noise and the Doppler noise, respectively. This paper focused on the Doppler noise under the demodulation scheme of polarization switching (PS) and phase generated carrier (PGC) hybrid processing method. A model describing the transformation from arbitrary leading fiber stretching to sensor phase background was presented. The complexity was that the Doppler noise was coupled with the birefringence states, as verified by both simulation and experiment. In response to this issue, a two-stage Doppler noise suppression method was proposed, which is based on the PS and PGC hybrid processing and a reference sensor. A processing procedure was presented where the polarization synthesis must be performed before and the reference sensor was considered. Otherwise, the suppression algorithm will be completely invalid due to the mutual coupling of the Doppler noise and the birefringence. Experimental results showed that only after the first stage of polarization synthesis, identical Doppler noise in the two TDM channels could be obtained, with an amplitude error of 0.02 dB. The second stage involved non-sensitive reference sensor subtraction, which achieved a maximum suppression of about 30 dB, which was the highest to be best of our knowledge. The two-stage Doppler noise suppression method was tested for sinusoidal and wideband leading fiber disturbances, providing a solution for practical interferometric FBG array applications.

Size Analysis Based on Sorption Study Data for Hydroxyapatite Nanoparticles

This work is devoted to the study on the possibility of applying the method of analyzing the particle size of hydroxyapatite at various stages of synthesis. A series of hydroxyapatite powders obtained by chemical deposition using microwave radiation is considered. Determination of the size of hydroxyapatite nanorods is carried out on the basis of data on the density and specific surface area. The specific surface area is analyzed by the sorption method. Determination of the ratio "length / diameter" of nanorods is based on the analysis of images obtained by scanning electron microscopy.

Synthesis of zeolites with hierarchical porous structures using a microwave heating method

Zeolites (ZSM-5) containing mesopores with a diameter of approximately 20 nm were hydrothermally synthesized using a microwave heating method. Microwave heating promoted the generation of zeolite nanocrystals in the initial stage of the hydrothermal synthesis, and then their self-assembly formed mesopores in the interstices. The formation of mesopores in the zeolites was confirmed by carrying out their surface analysis using scanning electron microscopy, pore size distribution measurements by obtaining N2 adsorption–desorption isotherms, and dye adsorption experiments.

Development of e-automated control system friction clutch of the vehicle

Problem. One of the most pressing problems of modern automotive industry is to simplify and facilitate driving. As for such a branch of the automotive industry as military equipment. One of the keys to successful completion of the task by the crew of any combat vehicle is the least possible distraction from the process of driving a vehicle and focus on the task. This is possible if the vehicle is provided with relatively comfortable driving conditions, good dynamic properties and the required minimum of controls. The solution to the issue of facilitating car driving cannot be solved without automation of transmission control. Goal. The aim of the project is to create a prototype of an electronic system of automated control of the friction clutch of a vehicle to increase the reliability and efficiency of special and military vehicles. Methodology. Analytical methods of research, program and full-scale modeling, experimental researches on real object of management are used. Originality. New interrelations between the structural elements of the actuator of the friction clutch are proposed, which allow to ensure the required speed of the actuator of the electropneumatic clutch control drive without losing control accuracy when using two electropneumatic valves. The proposed control algorithm of the actuator allows the use of both normally closed valves without residual pressure in the power cylinder. Practical value. The stages of synthesis of the electronic control system are carried out. The algorithm of operation of the tracking system with the use of PID-regulator and taking into account the features of the actuator is proposed and debugged. A new clutch pedal design with an induction sensor is proposed, which provides high accuracy and speed, and also requires only two wires to connect.

Mechanical Properties and Supramolecular Structure of Oriented Polyimide Films Filled with Carbon Nanofibers

The effect of carbon nanofibers introduced into the polyimide matrix on the mechanical properties of initial nanocomposite films and nanocomposite films oriented by uniaxial drawing at various stages of polyimide synthesis is studied. It is demonstrated that the storage moduli of nanocomposite films are higher compared to initial polyimide films at equal draw ratios. The self-orientation ability of the studied samples drawn at the stage of a prepolymer (poly(amic acid)) during thermal imidization is revealed, and it is shown that this ability increases upon the introduction of carbon nanofibers into the polyimide matrix. It is found that the polyimide films with the highest rigidity of macromolecules among the studied structures exhibit the highest storage moduli owing to their high self-orientation ability. Using X-ray diffraction and electron microscopy, a change in the supramolecular structure of rigid-chain polyimide films upon their orientational drawing at various stages of synthesis is investigated.

Elongation factor eEF2 kinase and autophagy jointly promote survival of cancer cells

Cells within solid tumours can become deprived of nutrients; in order to survive, they need to invoke mechanisms to conserve these resources. Using cancer cells in culture in the absence of key nutrients, we have explored the roles of two potential survival mechanisms, autophagy and elongation factor 2 kinase (eEF2K), which, when activated, inhibits the resource-intensive elongation stage of protein synthesis. Both processes are regulated through the nutrient-sensitive AMP-activated protein kinase and mechanistic target of rapamycin complex 1 signalling pathways. We find that disabling both autophagy and eEF2K strongly compromises the survival of nutrient-deprived lung and breast cancer cells, whereas, for example, knocking out eEF2K alone has little effect. Contrary to some earlier reports, we find no evidence that eEF2K regulates autophagy. Unexpectedly, eEF2K does not facilitate survival of prostate cancer PC3 cells. Thus, eEF2K and autophagy enable survival of certain cell-types in a mutually complementary manner. To explore this further, we generated, by selection, cells which were able to survive nutrient starvation even when autophagy and eEF2K were disabled. Proteome profiling using mass spectrometry revealed that these 'resistant' cells showed lower levels of diverse proteins which are required for energy-consuming processes such as protein and fatty acid synthesis, although different clones of 'resistant cells' appear to adapt in dissimilar ways. Our data provide further information of the ways that human cells cope with nutrient limitation and to understanding of the utility of eEF2K as a potential target in oncology.

Mixed matrix membranes based on NH2-MIL-53 (Al) and 6FDA-ODA polyimide for CO2 separation: Effect of the processing route on improving MOF-polymer interfacial interaction

This work compares the effect of two different fabrication routes on the gas separation performance of mixed matrix membranes (MMM). Flat-sheet symmetric membranes based on 6FDA-ODA as the matrix and 10–20 wt% metal–organic frameworks (MOF) MIL-53 (Al) and NH2-MIL-53 (Al) as fillers were fabricated via two approaches. In approach A, the MOF was incorporated at the early stage of the polyimide synthesis and the 6FDA-ODA polymerization reaction took place in the presence of MOF, while approach B followed the traditional solution mixing technique of MMM preparation. From the samples produced, XRD, N2 adsorption at 77 K, ATR-FTIR, FEG-SEM, TGA-DTG, DMA and density measurements were used to characterize the MOF structure and the membrane properties. Then, single and mixed gas separation performances were evaluated for CO2, CH4 and N2 at 2 and 5.5 bar and 35 °C. As a result of better interfacial interactions between NH2-MIL-53 (Al) and polyimide via hydrogen bonding, the MMM-A series showed excellent dispersion in the polymer matrix compared to MMM-B. At 10 wt% NH2-MIL-53, the membrane prepared by approach A showed 100% improvement in CO2/CH4 mixed gas separation factor (50:50 vol% CO2:CH4 at 35 °C and 5.5 bar) compared to that of neat 6FDA-ODA, which is 27% better than the membrane prepared by approach B. Better interfacial compatibility also improved the thermal and mechanical properties of the MMM, which confirms the efficiency of this approach for the NH2-MIL-53 (Al)/6FDA-ODA system. On the other hand, unfunctionalized MIL-53 (Al) MMM showed no difference between approach A and B in improving the gas separation performance.

Identification of signals as one of the stages of synthesis of the system of automatic stabilization of the height of the fluidized bed in the grain dryer

Drying is one of the most responsible and energy-intensive post-harvest grain pro-cessing operations. The constant rise in heat prices has led to the search for new designs of grain dryers, or improvements to existing ones. Studies of well-known scientists such as Romankov, Rezchikov, Rashkovskaya have proven the potential effectiveness of using a fluid-ized bed for drying grain.The degree to which this drying efficiency approaches the potential is determined by how much the change in the actual humidity of the material during drying approaches the theoretical drying curve at the same resource consumption and the same initial state of the material to be dried.The study of the designs of fluidized bed grain dryers showed that they show irregular fluctuations in the height of the fluidized bed, and, accordingly, the efficiency of energy use for drying. The reason for this phenomenon is related, on the one hand, to random fluctua-tions in the amount of grain in the fluidized bed, and on the other - to the shortcomings of the system of automatic stabilization of its height.Taking into account the provisions of the theory of optimal control indicates that max-imizing the accuracy of stabilization of a given value of the height of the fluidized bed should be achieved by developing an optimal multidimensional stabilization system of the specified height. The basis for solving the first of these is the study of the design of a fluidized bed grain dryer.The decomposition of the grain dryer allows to present it in the form of a set of multidimensional objects with pure delay. The size of this set is determined by the number of cascades, and the dynamic characteristics of its elements depend on the distance of the cascade to the gate.The degree of connections between input-output signals in the form of correlation and cross-correlation functions was studied, and the physical processes occurring in the grain dryer were analyzed. As a result of applying the Blackman-Tukey algorithm to the implemen-tations of the components of the control signal vectors and output signals, estimates of the corresponding correlation functions and spectral densities for all elements of the set of con-trol objects were obtained. The discrete Fourier transform of smoothed estimates of correla-tion and cross-correlation functions allowed us to calculate estimates of the spectral and mutual spectral densities of the respective signals. Approximation of spectral and mutual spectral density estimates by the method of generalized logarithmic frequency characteristics allowed to determine the mathematical description of these signals in the form of spectral density expressions, which will be the basis for the next stage of object identification.

Solgel synthesis of Gd2O3:Nd3+ nanopowders and the study of their luminescent properties

The paper presents the results of the sol-gel synthesis of Gd2O3:Nd3+ nanopowders by the citrate method, as well as the study of their structure and luminescent properties. A technique for using two different organic stabilizers with different thermal stability in sol-gel synthesis has been proposed and tested. The luminescent properties of the obtained Gd2O3:Nd3+ powders have been studied in the ultraviolet and near infrared spectral regions. The citrate sol-gel method was used to synthesize the materials. Aqueous solutions of metal nitrates were used as the main initial components. Citric acid and polyvinylpyrrolidone were used as organic modifying components, playing a double role in the synthesis process, i.e. acting as stabilizers of forming nanoparticles in colloidal solutions and serving as a fuel additive in the process of heat treatment of materials. Infrared spectroscopy and differential thermal and thermogravimetric analyses were used to study the evolution of the structure of materials during synthesis. Crystalline Gd2O3:Nd3+ nanopowders were obtained by a low-temperature sol-gel method using citric acid and polyvinylpyrrolidone as stabilizers. The data of infrared spectroscopy and differential thermal and thermogravimetric analyses show that the formation of Gd2O3:Nd3+ nanoparticles begins at the stage of the crude gel and the evolution process develops during the drying and heat treatment of materials. It is shown that the use of two different organic stabilizers with different thermal stability provides stabilization of the forming Gd2O3:Nd3+ nanoparticles at different stages of synthesis in a wide temperature range. The luminescence spectra are observed in the UV spectral region under excitation of the synthesized nanopowders by radiation with a wavelength of 238 nm. They are determined by electronic transitions in the Gd2O3 crystalline matrix. The synthesized Gd2O3:Nd3+ nanopowders exhibit intense photoluminescence in the UV and near-IR spectral regions. The results can be used in the development of a technology for the synthesis of various composite phosphors, as well as in the creation of luminescent nanopowders for nanothermometry in medicine.

The Exosome-Associated Tetraspanin CD63 Contributes to the Efficient Assembly and Infectivity of the Hepatitis B Virus.

Currently, the hepatocellular trafficking pathways that are used by the hepatitis B virus (HBV) during viral infection and shedding are poorly defined. It is known that the HBV uses late endosomal and multivesicular body (MVB) compartments for assembly and release. The intraluminal vesicles (ILVs) generated within MVBs have also been implicated in the late synthesis stages of a variety of pathogenic viruses. We recently observed that the HBV within infected hepatocytes appears to associate with the tetraspanin protein CD63, known to be a prominent and essential component of ILVs. Immunofluorescence microscopy of HBV‐expressing cells showed that CD63 colocalized with HBV proteins (large hepatitis B surface antigens [LHBs] and hepatitis B core) and labeled an exceptionally large number of secreted extracellular vesicles of uniform size. Small interfering RNA (siRNA)–mediated depletion of CD63 induced a substantial accumulation of intracellular LHBs protein but did not alter the levels of either intracellular or extracellular HBV DNA, nor pregenomic RNA. Consistent with these findings, we found that markedly less LHBs protein was associated with the released HBV particles from CD63 siRNA‐treated cells. Importantly, the HBV viral particles that were shed from CD63‐depleted cells were substantially less infective than those collected from control cells with normal CD63 levels. Conclusion: These findings implicate the tetraspanin protein CD63 as a marker and an important component in the formation and release of infectious HBV particles.