We developed a composite optical material composed of nanotubes and graphene nanoribbons (GNRs). We found that the macroscopic optical response of the composite is strongly governed by the specific combination of graphene nanoribbons and nanotube hosts, namely metallic and semiconducting single-walled carbon nanotubes (SWCNTs) and multi-walled boron nitride nanotubes (MWBNNTs). Selective synthesis of graphene nanoribbons was achieved using a bottom-up approach based on 4,4 ''-dibromo-p-terphenyl and 10,10 '-dibromo-9,9 '-bianthracene molecular precursors. Specifically, armchair graphene nanoribbons (AGNRs) with widths of 3, 6, 7, and 9 carbon atoms were synthesized on the surface and/or inside the nanotubes. The formation and structure of the GNRs were verified by Raman spectroscopy and high-resolution electron microscopy. The incorporation of AGNRs into nanotube films results in optical media with controllable absorption in the UV-visible spectral range. Moreover, a pronounced modification of the photoluminescence (PL) response of both carbon and boron nitride nanotube films was observed upon the formation of 3-AGNRs and 7-AGNRs within nanotubes. The 3-AGNRs exhibit different PL in carbon and boron nitride nanotubes due to PL quenching and energy transfer. Films and aqueous suspensions of GNRs@NTs show high stability over time as well as under intense ultrasonic treatment. These findings demonstrate that GNRs@NTs can serve as versatile platforms for printed and thin-film technologies in the development of active and passive components for optoelectronic devices.

6- atom-wide armchair graphene nanoribbons (6-AGNRs) are synthesized through two-step process inside a matrix of single-walled carbon nanotubes (SWCNTs) pre-aligned by controlled vacuum filtration method. The typical Raman modes of nanoribbons as radial breathing-like mode at 453 cm-1, edge CH mode at 1245 cm-1 and middle-range mode at 1270 cm-1 appear in the Raman spectra alongside with the modes of carbon nanotubes. Polarized Raman spectra reveal the strong anisotropy of the signal depending on the orientation of the sample, as the alignment of nanoribbons is provided by the alignment of the nanotube host matrix. This result is in agreement with polarized Raman density functional theory (DFT) calculations carried out for the main vibrational modes of the 6-AGNR. The proposed method ensures the alignment of graphene nanoribbons (GNRs) on a macroscale and preserves the anisotropy of their optical properties.

In this study, we demonstrated the remarkable sensitivity to electrochemical local charge of sulfur chains encapsulated in small-diameter single-walled carbon nanotubes (S@SWCNTs). To perform micro- and macro-spectroscopic probing, a transparent electrochemical cell was designed in which the charging electrode is formed based on S@SWCNTs. During a short-term electrochemical charging, significant reversible changes were observed in-situ in both Raman and UV-vis-Nir spectra of S@SWCNTs. The optical response was found to depend on the magnitude and sign of the charge, as well as on the duration of the electrochemical charging process at a given potential. The enhanced Raman modes of sulfur chains exhibited a notable linear shift (up to 10 cm-1) accompanied by a redistribution of their intensities. A correlation is identified of the chronoamperometry curve (charging current versus time) and transformations of the Raman spectrum of single-atom sulfur chains. Atomistic simulations allowed to attribute these changes in the Raman spectrum to the softening of the sulfur bonds upon charging. Our findings revealed that the nanotube inhibits the chemical interactions between encapsulated sulfur and local charge sources, thus rendering S@SWCNTs suitable for repeated utilization in local charge analysis.

A description is given of simulation experiments of the interaction of lunar dust with the surface of solar panels. The experiments are based on the creation of a dust plasma cloud by exposure of a substance simulating lunar dust to the radiation from a powerful pulse gyrotron. This approach has been tested using a lunar regolith simulant. An analysis is presented of the results of precipitation of charged regolith particles on solar panels of various types and variation in their efficiency.

Nanophotothermolysis (NPhT) effect is considered to be an approach for the development of highly selective modalities for anticancer treatment. Herein, we evaluated an antitumor efficacy of NPhT with intravenously injected zinc phthalocyanine particles (ZnPcPs) in murine subcutaneous syngeneic tumor models. In S37 sarcoma-bearing mice a biodistribution of ZnPcPs was studied and the high antitumor efficacy of ZnPcPs-mediated NPhT was shown, including a response of metastatic lesions. The morphological investigation showed the main role of a local NPhT-induced vascular damage in the tumor growth and tumor spread inhibition. Murine tumors of different histological origin were not equally sensitive to the treatment. The results demonstrate a potential of ZnPcPs-mediated NPhT for treatment of surface tumors.

Co-precipitation of biopolymers into calcium carbonate crystals changes their physicochemical and biological properties. This work studies hybrid microcrystals of vaterite obtained in the presence of natural polysaccharides, as carriers for the delivery of proteins and enzymes. Hybrid microcrystals with dextran sulfate, chondroitin sulfate, heparin, fucoidan, and pectin were obtained and compared. The impact of polysaccharides on the morphology (particle diameter, surface area, nanocrystallite and pore size), polysaccharide content and surface charge of hybrid microcrystals was studied. Only microcrystals with fucoidan and heparin exhibited antioxidant activity against •ОН radical. The surface charge and pore size of the hybrid microcrystals affected the sorption of albumin, catalase, chymotrypsin, mucin. A decrease in the catalytic constant and Michaelis constant was observed for catalase sorbed on the hybrid crystals. The biocompatibility of microcrystals depended on the nature of the included polysaccharide: crystals with sulfated polysaccharides increased blood plasma coagulation but not platelet aggregation, and crystals with dextran sulfate had the greatest cytotoxicity against HT-29 cells but not erythrocytes. Hybrid microcrystals with all polysaccharides except chondroitin sulfate reduced erythrocyte lysis in vitro compared with vaterite crystals. The obtained results enable to create novel carriers based on hybrid vaterite crystals with polysaccharides, beneficial for the delivery of protein drugs.

В эксперименте получены плазменно-пылевые облака из вещества метеорита Царев, имитатора лунного реголита LMS-1D и ильменитового концентрата с помощью микроволнового разряда в порошковых средах. Для каждого из образцов зарегистрирована динамика развития разряда и образования плазменно-пылевого облака с последующей релаксацией после окончания микроволнового импульса. По спектрам излучения плазмы и поверхности твердого тела определены температуры газа, электронов и поверхности. Проведенное сравнение фазового и элементного состава исходных образцов и образцов после воздействия плазмы показало, что существенного изменения состава не происходит. Однако результаты сканирующей электронной микроскопии четко указывают на сфероидизацию исходных угловатых частиц и частиц неправильной формы. Также наблюдается появление сферических частиц, размеры которых больше, чем линейные размеры частиц в исходном образце. Полученные результаты указывают на возможность использования таких экспериментов для исследования химических и плазмохимических процессов синтеза и модификации веществ в условиях плазменно-пылевых облаков, встречающихся в космических явлениях.

Ceria-based solid solutions (M0.01Ce0.99O2) with low-content dopants were synthesized by the co-precipitation method, followed by calcination at the temperature of 500 degrees C. The effect of doping on catalytic performance in CO oxidation was investigated, and the catalyst physicochemical properties were studied. The introduction of even a small amount of metal dopants significantly increased the activity of catalysts. Thus, the most active catalysts were systems when doping ceria with metals Cu, Mn, and Co, i.e., with a small ionic radius and having multivalent oxidation states. It is shown that the high activity was a result of the increased interaction of M delta+ with ceria due to facile electron exchange between M delta+ and Ce4+/Ce3+, the redox cycle was one of the key factors in the CO oxidation, as well as well-integrated metal species in ceria lattice, especially in subsurface layer.

The paper reports a possibility of using high-power femtosecond laser pulses for imaging and subsequent study (by means of optical microscopy) of small-scale structural inhomogeneities in synthetic diamond single crystals. The irradiation of diamond by laser pulses in the intense self-focusing mode creates conditions for multiple optical microscopic breakdowns, whose distribution in the diamond bulk reflects spatial oscillations of local breakdown threshold. The breakdown-produced sp2 inclusions form ordered stripe microstructures with a characteristic period of several microns. It is shown that spatial oscillations of breakdown threshold correlate with changes in the local concentration of impurity–vacancy defects NV and SiV.

A high mobility of charge carriers and a low sheet resistance in graphene are the key indicators of its quality and applicability in electronic devices. In turn, the mobility of charge carriers in graphene is determined by graphene film smoothness. The electron scattering on structure defects of graphene film (wrinkles and grain boundaries) strongly affects the charge carrier mobility. In this work a simple and ultrafast approach for synthesis of graphene monolayer with the controllable smoothness and wrinkle density onto a resistively heated copper foil is presented. The method is a cold-wall chemical vapor deposition from methane. The fast synthesis of graphene with a full process cycle of 3 min is demonstrated. The structural defect density of polycrystalline graphene is optimized by appropriate combinations of methane concentration in the chamber and duration of synthesis process. Under the lower concentration of methane with the longer synthesis time the lower defect density in graphene appeared. The increase of process time from 30 s up to 10 min (under the decrease of methane concentration from 4.5 % to 0.36 %, respectively) leads to increase of average distance between wrinkles in graphene film from 6 µm to 35 µm. А charge carrier mobility as high as 2170 cm2V−1s−1 and a sheet resistance as low as 318 Ohm/□ under the lowest wrinkle density are measured for graphene polycrystalline monolayer deposited onto SiO2 substrate.

An original plasma chemical process initiated by microwave discharge in a mixture of metal and dielectric powders was applied to prepare specific materials, which consisted of microsized spherical particles of aluminum oxide covered with silver nanoparticles. The prepared materials are highly uniform in shape, size distribution, and composition. Their cytotoxicity was investigated using the human cell lines MCF7, HEK293T, A549, and VA-13 and the bacterial strains E. coli JW5503 (ΔtolC) and E. coli K12. Their cytotoxicity was found not to exceed the cytotoxicity of the starting materials. Thus, the prepared materials can be considered highly promising for catalysis and biotechnology applications.

Glycans of MVs are proposed to be candidates for mediating targeting specificity or at least promoting it. In contrast to exosomes, glycomic studies of MVs are largely absent. We studied the glycoprofile of endothelial cell-derived MVs using 21 plant lectins, and the results show the dominance of oligolactosamines and their α2-6-sialylated forms as N-glycans and low levels of α2-3-sialylated glycans. The low levels of α2-3-sialosides could not be explained by the action of extracellular glycosidases. Additionally, the level of some Man-containing glycans was also decreased in MVs. Spatial masking as the causative relationship between these low level glycans (as glycosphingolipids) by integral proteins or proteoglycans (thus, their lack of interaction with lectins) seems unlikely. The results suggest that integral proteins do not pass randomly into MVs, but instead only some types, differing in terms of their specific glycosylation, are integrated into MVs.

The article describes simulation experiments of interaction of lunar dust with the surface of solar panels. The experiments are based on the creation of a dusty plasma cloud, when the radiation of a powerful pulsed gyrotron is exposed to a substance that simulates lunar dust. This approach was tested using a lunar regolith simulator. The analysis of the results of deposition of charged regolith particles on solar panels of different types and changes in their efficiency is presented.

An original plasma-chemical facility has been developed at the Prokhorov General Physics Institute of the Russian Academy of Sciences based on the gyrotrons of the thermonuclear complex of the L-2 M/MIG-3 stellarator. The scope of its applications includes the synthesis of powders for new types of catalysts, the formation and doping of ceramics, and other applications. We have previously demonstrated that in specific conditions, chain oscillatory reactions can be initialized in the reactor by powerful microwave pulses of the gyrotron in mixtures of metal and dielectric powders, resulting in the formation of microdispersed materials with controllable physical and chemical properties.In such reactions, initiated in mixtures of Ti and B, BN powders in a series of particle samples with a developed surface have been obtained. The resulting materials have a heterogeneous composition and size distribution controlled by the synthesis conditions. Thus, the obtained structures exhibit repeatable characteristics attractive for numerous applications, from catalytic particle formation and reinforcement additives to biomedical materials. In order to analyze the hazardless of the materials, cytotoxicity tests were necessary.In this work, the methods for such an analysis have been applied. The study of the obtained samples for cytotoxicity against human cells (lines HEK293T, MCF7, A549, VA13) showed toxic effects only at concentrations of tens of mg/L and the absence of detectable toxic effects in bacterial system (E. coli). The low toxicity at the cellular level indicates the potential for the safe use of the proposed microstructures, but requires further testing of safety at the organism level.

In the experiment, plasma–dust clouds were obtained from the substance of the Tsarev meteorite, a simulant of lunar regolith LMS-1D and ilmenite concentrate using a microwave discharge in powder media. For each of the samples, the dynamics of the development of the discharge and the formation of a plasma–dust cloud with subsequent relaxation after the end of the microwave pulse were recorded. From the emission spectra of the plasma and the surface of a solid body, the temperatures of the gas, electrons and surface were determined. A comparison of the phase and elemental composition of the initial samples and samples after exposure to plasma showed that there is no significant change in the composition. However, scanning electron microscopy results clearly indicate spheroidization of the original angular and irregularly shaped particles. The appearance of spherical particles is also observed, the dimensions of which are larger than the linear dimensions of the particles in the original sample. The results obtained indicate the possibility of using such experiments to study chemical and plasma-chemical processes of synthesis and modification of substances under conditions of plasma–dust clouds encountered in space phenomena.

The features of the use of carborane and other hydrogen-containing additives as a catalyst in the synthesis of micro-sized particles in processes initiated by gyrotron radiation in mixtures of boron nitride (BN) powders with a cubic (c) or hexagonal (h) structure and metals are presented [1, 2]. The regimes in which the transition from the cubic phase of boron nitride to the hexagonal phase is possible are described.

Information about experiments on obtaining oxide, nitride, and oxynitride materials in a microdispersed state with a given composition and a complex surface using high-power pulsed gyrotron discharges in mixtures of Al/AlN and Al/Si 3 N 4 powders is presented. The synthesis of nanosized particles (>10 nm) and microparticles (from 1 to 100 μm) with a complex surface is demonstrated. Micrographs of the surface of the obtained particles and their morphological composition are presented. The obtained materials are considered as carriers for catalysts.

We present a description of a plasma-chemical facility designed for synthesis of micro- and nanoparticles using the radiation of a high-power gyrotron. The facility has been developed at the Plasma Physics Division of A.M.Prokhorov General Physics Institute of the Russian Academy of Sciences. The facility includes a plasma-chemical reactor, a gyrotron unit, an in-line calorimeter, a diagnostic system, which ensures video and spectroscopic measurements, balance measurements of the microwave radiation, and thermal imagery measurements, a chemical unit for specimen preparation and analysis of synthesis products, an electronic logging unit, and a specimen labeling system for organization and storage of a large amount of experimental data and specimens.

Nanoscale morphological features of branched processes of glial cells may be of decisive importance for neuron–astrocyte interactions in health and disease. The paper presents the results of a correlation analysis of images of thin processes of astrocytes in nervous tissue of the mouse brain, which were obtained by scanning probe microscopy (SPM) and transmission electron microscopy (TEM) with high spatial resolution. Samples were prepared and imaged using a unique hardware combination of ultramicrotomy and SPM. Astrocyte details with a thickness of several tens of nanometers were identifiable in the images, making it possible to reconstruct the three-dimensional structure of astrocytic processes by integrating a series of sequential images of ultrathin sections of nervous tissue in the future.