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The aim of the study was to investigate the effect of the addition of graphene oxide (GO) on the rheological and mechanical properties of extruded polyamide 12 (PA12) filaments with high aluminum oxide (Al2O3) content used for 3D printing using the fused filament fabrication (FFF) method. Firstly, Al2O3-based mixtures with 0.10, 0.25 and 0.50 vol.% GO content were prepared. These mixtures were dried and subsequently combined with paraffin wax (PW), stearic acid (SA) and polyamide 12 (PA12) in an organic solvent. After drying in a vacuum oven and sifting, powder compositions of 74 wt.% (Al2O3 + GO)/26 wt.% (PA12 + PW + SA) with different GO content were obtained. All compositions were successfully extruded into filaments for 3D printing. Rheological, microstructural and mechanical studies of the compositions and filaments were carried out. X-ray diffraction phase analysis and Raman spectroscopy were also performed. It was shown that 0.10 and 0.25% vol. GO proved to be a universal additive that resulted in an increase in the rheological and mechanical properties of the highly filled polymer and also improved its 3D printability, which ultimately helped obtain a ceramic product with complex shape using the FFF method.

Changes in the morphology of betulin crystals during heating at selected temperatures corresponding to polymorphic transformations were investigated. It was shown that the prismatic crystals of starting betulin form III were converted into needles at 120 °C after water removal, followed by the III→II polymorphic transformation. During further heating up to 180 °C, the whiskers of betulin form I were grown. Experiments on betulin heating in the presence of dicarboxylic acids, adipic or suberic showed that the morphological changes can serve as a test for the formation of cocrystals. According to morphological changes, the formation of cocrystals of betulin with adipic acid under heating was identified. The interaction of adipic acid vapor with the surface of betulin crystals was suggested. In contrast, morphological changes in the mixture of betulin and suberic acid under heating provided only the evidence of polymorphic transformations of the components. The results on cocrystal formation by heating were compared with the preparation of cocrystals by the liquid-assistance grinding method. Despite the fact that polymorphic forms with a high surface area were formed when betulin was heated, dissolution studies showed that the starting betulin polymorph III exhibited the highest dissolution rate in comparison with betulin polymorphs obtained under heating.

A new method for assessing the quality of fibre coating based on a combination of fluorescence microscopy and electron paramagnetic resonance is presented in this work. An influence of the carboxymethylcellulose/polyvinylamine gel preparation method on the mobility of the spin label was established. The mobility of the spin label changes from 3.5 ns in the case of a polyvinylamine solution to 12.8 ns in the case of a cross-linked gel on the surface of the glass fibre. A qualitative relationship was found between the mobility of the spin label in the gel applied to the glass fibre and the rate of spreading of crude oil over its surface. This method can be used to make membranes for the separation of water-in-oil emulsions.

For the first time, hydroxyquinol and sesamol electrochemical amperometric determination in tahini halva and lokum Turkish delights has been described. The electroanalytical process is given by amavadin-modified conducting polymer, in which both monomer and dopant may be natural compounds. Taking into account the ionic nature of the modifier, even in neutral medium the oscillatory behavior will be more probable in this system than in the simplest cases. Nevertheless, the amavadin-modified conducting polymer may be efficient electrode modifier for hydroxyquinol and sesamol electrochemical determination in Turkish delights like lokum and tahini halva.

The paper analyzes the prospects of using a heat-accumulating material consisting of metallized polyethylene granules. X-ray diffraction analysis has been used to study the influence of the number of heating and cooling cycles of the heat-accumulating material on the change in the degree of crystallinity of polyethylene. It was shown that the proposed heat-accumulating material showed a low resistance and a significant decrease in the degree of crystallinity of polyethylene under the experimental conditions. The crystal structure of polyethylene did not change during cyclic heating and cooling. Grounded on the obtained experimental results, it was determined that a high degree of polyethylene crystallinity is being kept for 200–300 heating-cooling cycles.

Plasmonic sensors have great potential for widespread usage. However, the prohibitive cost of noble metals restrains the wider adoption of these devices. The aim of our study is to develop a cost-effective Al-based alternative to common noble metal-based plasmonic detectors. We considered a structure consisting of an n-type doped Si wafer with a shallow p-n junction and an overlying Al grating with a trapezoidal groove profile. The RCWA (rigorous coupled-wave analysis) method was used to numerically calculate the distribution of absorbed light energy in the plasmonic detector layers and to optimize the grating parameters. Based on the simulation results, experimental samples of plasmonic photodetectors with optimal grating parameters (period—633 nm, relief depth—50 nm, groove filling factor—0.36, and thickness of the intermediate Al layer—14 nm) were manufactured, and their properties were studied. For these samples, we obtained a polarization sensitivity value of Ip/Is = 8, an FWHM of the resonance in the photocurrent spectrum ranging from 50 to 100 nm, a sensitivity at the resonance maximum of Iph = 0.04–0.06 A/W, and an angular half-width of photocurrent resonance of Δθ = 5°, which are comparable to noble metal-based analogs. Our results may be used for creating cost-effective high-sensitivity plasmonic sensors.

The aim of this research was to obtain the grafted copolymer of chitosan with acrylamide using the electron beam irradiation. Radiation dose was varied from 6 to 160 kGy. The highest yield of the product was observed at radiation dose of 12–40 kGy. Further increase in the dose caused a decrease in the product yield as well as its solubility in water. Using gel permeation chromatography, it was confirmed that unreacted chitosan remained in the product. NMR study of the water-soluble part of the product obtained under the doses of 6, 12, and 20 kGy showed that the length of the side chains of grafted acrylamide was about 2 elementary units. Investigation of chitosan solutions by means of dynamic light scattering revealed the presence of chitosan agglomerates in the solution. The possibility of obtaining dense films was demonstrated. Mechanical treatment of the copolymer in the ball mill caused an increase in the solubility of the samples obtained even at radiation doses of 80 and 160 kGy. It was determined by means of chromatographic methods that there were no products with low molecular weight in the ball-milled product, and unreacted chitosan did not undergo mechanocracking during the mechanical treatment.

The development of new and effective antibacterials for pharmaceutical or cosmetic skin care that have a low potential for the emergence and expansion of bacterial resistance is of high demand in scientific and applied research. Great hopes are placed on alternative agents such as bactericidal peptidoglycan hydrolases, depolymerases, etc. Enzybiotic-based preparations are being studied for the treatment of various infections and, among others, can be used as topical formulations and dressings with protein-polysaccharide complexes. Here, we investigate the antibiofilm properties of a novel enzybiotic cocktail of phage endolysin LysSi3 and bacteriocin lysostaphin, formulated in the alginate gel matrix and its ability to control the opportunistic skin-colonizing bacteria Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumoniae, as well as mixed-species biofilms. Our results propose that the application of SiL-gel affects different components of biofilm extracellular polymeric substances, disrupts the matrix, and eliminates the bacteria embedded in it. This composition is highly effective against biofilms composed of Gram-negative and Gram-positive species and does not possess significant cytotoxic effects. Our data form the basis for the development of antibacterial skin care products with a gentle but effective mode of action.

The development of multimodal nano- and micro-structures has become an increasingly popular area of research in recent years. In particular, the combination of two or more desirable properties within a single structure opens multiple opportunities from biomedicine, sensing, and catalysis, to a variety of optical applications. Here, for the first time, we report the synthesis and characterization of multimodal chiroptically active CaCO3 nanocomposites. These composites have been prepared by a modified microemulsion method in the presence of an amino acid (cysteine). Following this, additional modalities have been introduced by loading the composites with luminescent nanoparticles or doping with Eu3+ ions. The luminescent composites have been produced by the incorporation of CuInZnS/ZnS or CdSe@ZnS/ZnS core/shell quantum dots, or via doping with trivalent europium. In this manner, we have produced chiroptically active composites with orange, green, and red luminescence. Overall, this work demonstrates the unique advantage and potential of our approach and new class of chiroptically active CaCO3 nanocomposites, which display tunable functionality to specific requirements via the incorporation of desired ions, nanoparticles, and chirality of the structure.

This work belongs to the development of mechanical force-responsive drug delivery systems based on remote stimulation by an external magnetic field at the first stage, assisting the positioning of a ferrogel-based targeted delivery platform in a fluid flow. Magnetically active biopolymer beads were considered a prototype implant for the needs of replacement therapy and regenerative medicine. Spherical calcium alginate ferrogels (FGs)~2.4 mm in diameter, filled with a 12.6% weight fraction of magnetite particles of 200–300 nm in diameter, were synthesized. A detailed characterization of the physicochemical and magnetic properties of FGs was carried out, as were direct measurements of the field dependence of the attractive force for FG-beads. The hydrodynamic effects of the positioning of FG-beads in a fluid flow by a magnetic field were studied experimentally in a model vessel with a fluid stream. Experimental results were compared with the results of mathematical and computer modeling, showing reasonable agreement. The contributions of the hydrodynamic and magnetic forces acting on the FG-bead in a fluid flow were discussed. Obtained forces for a single ferrogel implant were as high as 0 to 10−4 N for the external field range of 0 to 35 kA/m, perfectly in the range of mechanical force stimuli in biological systems.

Techniques for the formation of thin polymer films based on polymethyl methacrylate and composite coatings with silicon dioxide nanoparticles on glass and silicon substrates have been optimised, and their structural characteristics have been studied by atomic force microscopy. The effect of the introduction of silicon dioxide nanoparticles and their content on the structure and wettability of the formed composite coatings is described. Experimental data are presented which prove that the incorporation of SiO2 nanoparticles into the structure of the polymethyl methacrylate polymer matrix leads to changes in the roughness parameters of the coatings.

The dissolution of bituminous coal at mild temperature was studied using a variety of commercially available coal- and petroleum-derived hydrocarbon fractions, hydrorefined derivatives and blends as solvents. The chemical and molecular composition of the coal, solvents and extracts were characterized by chemical and group analyses, and by IRFT, 1H NMR, GC-MS and liquid chromatography. Low volatile solvents like highly aromatic coal tar (CT), its anthracene fraction (AFCT), petroleum-derived solvent (HGOCC) and binary blends were found to exhibit high performance for coal dissolution into quinoline solubles (to 79‒82%), and the yields of gases being no more than 0.5%. The extracts obtained using CT and AFCT solvents represented pitch-like matter consisting of rarely substituted aromatic molecules with 4‒5 condensed rings. HGOCC extract was much less aromatic, the aromatic rings being highly substituted with fairly large alkyl substituents. The blended solvents yielded more extracts, and their molecular indexes were average between those obtained with each solvent separately. A remarkable finding was that the extracts obtained were characterized by significantly lower content of benzo(a) pyrene (BaP) compared to solvents used, its content further decreased as the time of coal dissolution increased.

Objectives. The objectives of this work are the development of a multi-primer system based on the polymerase chain reaction (PCR) aimed at the simultaneous detection of six bacterial pathogens that cause human pneumonia and the determination of the parameters important for the optimization of this multi-primer system, including solid-phase PCR systems (biological microarrays).Methods. To determine the optimal parameters of the system, PCR methods were used in monoplex and multiplex formats.Results. Primers for Staphylococcus aureus, Pseudomonas aeruginosa, Haemophilus influenza, Legionella pneumophila, Klebsiella pneumoniae, and Streptococcus pneumoniae detection were designed, and the PCR cycling conditions were optimized. The patterns of primer design for solidphase PCR were revealed.Conclusions. The developed prototype of a system specifically identifies six clinically significant bacterial pathogens. It could be expanded for the analysis of viral and fungal pathogens and used in clinical diagnostics. A prototype of a system for pathogenic agent detection in the immobilized phase (biological microarray) was created.

Applications of DNA-containing nanomaterials (DNA-NMs) in science and technology are currently attracting increasing attention in the fields of medicine, environment, engineering, etc. Such objects have become important for various branches of science and industries due to their outstanding characteristics such as small size, high controllability, clustering actions, and strong permeability. For these reasons, DNA-NMs deserve a review with respect to their recent advancements. On the other hand, precise cluster control, targeted drug distribution in vivo, and cellular micro-nano operation remain as problems. This review summarizes the recent progress in DNA-NMs and their crossover and integration into multiple disciplines (including in vivo/in vitro, microcircles excisions, and plasmid oligomers). We hope that this review will motivate relevant practitioners to generate new research perspectives and boost the advancement of nanomanipulation.

Within this work, new aerogels based on graphene oxide are proposed to adsorb salicylic acid (SA) and herbicide 2,4-Dichlorophenoxyacetic acid (2,4-D) from aqueous media. Graphene oxide aerogel (GOA) and reduced graphene oxide aerogel (rGOA) were obtained by freeze-drying processes and then studied by Raman spectroscopy, Fourier-transform infrared spectroscopy (FT-IR), and Brunauer–Emmett–Teller (BET) analysis. The influence of contact time and the concentration of the adsorbates were also assessed. It was found that equilibrium for high adsorption is reached in 150 min. In a single system, the pseudo-first-order, pseudo-second-order kinetic models, Intraparticle diffusion, and Elovich models were used to discuss the detail of the aerogel adsorbing pollutant. Moreover, the Langmuir, Freundlich, and Temkin adsorption models were applied to describe the equilibrium isotherms and calculate the isotherm constants.

The chemical composition, structural and plastometric properties of typical different-ranked coals from Mongolia deposits were studied. The non-isothermal iso-conversion Ozawa-Flynn-Wall method was used to assess kinetic parameters and to differentiate decomposition steps. Key peculiarities of the pyrolysis kinetics of brown and bituminous coals were revealed and discussed in terms of the composition and plastometric properties of coals. Brown coal was shown to undergo three decomposition steps with ever increasing activation energy as temperature increased because of the decomposition of thermally more and more stable molecular fragments. The pyrolysis of bituminous coals occurred in four steps, the activation energy having an extreme mode of temperature dependence. An important new finding was that the temperature range of the second, major pyrolysis step well corresponded to that between the softening and resolidification temperatures according to Gieseler plastometry, so that the decomposition of bituminous coals at the second step proceeded in a fluid-like medium, moreover, with constant activation energy. The yield and composition of the pyrolysis products obtained under isothermal conditions were also characterized depending on coal rank and temperature, and the ways for qualified utiliza tions were offered.

Ni46Mn41In13 (close to 2-1-1 system) Heusler alloy was studied by magnetization measurement dependence on the temperature in magnetic fields of up to 13.5 T. The magnetocaloric effect measured by the direct method in quasi-adiabatic conditions showed a maximum value of ∆Tad = −4.2 K at a temperature T = 212 K in a magnetic field of 10 T in the region of martensitic transformation. The structure of the alloy was studied by transmission electron microscopy (TEM) as a function of the temperature and the thickness of the sample foil. In the temperature range from 353 to 215 K, at least two processes were established. The results of the study indicate that the concentration stratification occurs according to the mechanism of spinodal decomposition (conditionally spinodal decomposition) into nanoscale regions. At a temperature of 215 K and lower, martensitic phase with 14 M modulation is observed in the alloy at thicknesses greater than 50 nm. Some austenite is also observed. In foils with thickness of less than 50 nm in a temperature range from 353 to 100 Km only the initial austenite, which has not transformed, was found.

GYAGG:Tb (Ce) scintillators have been confirmed to be promising sources of light emission when excited by an intense 150 keV electron beam. The saturation of the scintillation yield under such excitation conditions has been studied. To explain the results obtained, a model that considers the Auger quenching mechanism was used. The Ce-doped material did not show saturation, whereas a moderate 30% drop of the yield was measured in the Tb-doped sample at the highest excitation beam intensity ~1 A/cm2. This put forward a way to exploit the Tb-doped scintillator for indirect β-voltaic batteries.

Objectives. This study was aimed at the investigation of the supramolecular systems based on cationic surfactants bearing cyclic head groups (imidazolium and pyrrolidinium) and polyanions (polyacrylic acid (PAA) and human serum albumin (HSA)), and factors governing their structural behavior to create functional nanosystems with controlled properties. Research hypothesis. Mixed PE–surfactant complexes based on oppositely charged species are characterized by multifactor behavior strongly affected by the nature of both components. It was expected that the transition from a single surfactant solution to an admixture with PE might provide synergetic effects on structural characteristics and functional activity. To test this assumption, the concentration thresholds of aggregation, dimensional and charge characteristics, and solubilization capacity of amphiphiles in the presence of PEs have been determined by tensiometry, fluorescence and UV-visible spectroscopy, and dynamic and electrophoretic light scattering. Results. The formation of mixed surfactant–PAA aggregates with a hydrodynamic diameter of 100–180 nm has been shown. Polyanion additives led to a decrease in the critical micelle concentration of surfactants by two orders of magnitude (from 1 mM to 0.01 mM). A gradual increase in the zeta potential of HAS–surfactant systems from negative to positive value indicates that the electrostatic mechanism contributes to the binding of components. Additionally, 3D and conventional fluorescence spectroscopy showed that imidazolium surfactant had little effect on HSA conformation, and component binding occurs due to hydrogen bonding and Van der Waals interactions through the tryptophan amino acid residue of the protein. Surfactant–polyanion nanostructures improve the solubility of lipophilic medicines such as Warfarin, Amphotericin B, and Meloxicam. Perspectives. Surfactant–PE composition demonstrated beneficial solubilization activity and can be recommended for the construction of nanocontainers for hydrophobic drugs, with their efficacy tuned by the variation in surfactant head group and the nature of polyanions.

Nowadays, magnetoelectric nanomaterials are on their way to finding wide applications in biomedicine for various cancer and neurological disease treatment, which is mainly restricted by their relatively high toxicity and complex synthesis. This study for the first time reports novel magnetoelectric nanocomposites of CoxFe3−xO4-BaTiO3 series with tuned magnetic phase structures, which were synthesized via a two-step chemical approach in polyol media. The magnetic CoxFe3−xO4 phases with x = 0.0, 0.5, and 1.0 were obtained by thermal decomposition in triethylene glycol media. The magnetoelectric nanocomposites were synthesized by the decomposition of barium titanate precursors in the presence of a magnetic phase under solvothermal conditions and subsequent annealing at 700 °C. X-ray diffraction revealed the presence of both spinel and perovskite phases after annealing with average crystallite sizes in the range of 9.0–14.5 nm. Transmission electron microscopy data showed two-phase composite nanostructures consisting of ferrites and barium titanate. The presence of interfacial connections between magnetic and ferroelectric phases was confirmed by high-resolution transmission electron microscopy. Magnetization data showed expected ferrimagnetic behavior and σs decrease after the nanocomposite formation. Magnetoelectric coefficient measurements after the annealing showed non-linear change with a maximum of 89 mV/cm*Oe with x = 0.5, 74 mV/cm*Oe with x = 0, and a minimum of 50 mV/cm*Oe with x = 0.0 core composition, that corresponds with the coercive force of the nanocomposites: 240 Oe, 89 Oe and 36 Oe, respectively. The obtained nanocomposites show low toxicity in the whole studied concentration range of 25–400 μg/mL on CT-26 cancer cells. The synthesized nanocomposites show low cytotoxicity and high magnetoelectric effects, therefore they can find wide applications in biomedicine.

The review is devoted to the analysis of the compositional disordering potential of the crystal matrix of a scintillator to improve its scintillation parameters. Technological capabilities to complicate crystal matrices both in anionic and cationic sublattices of a variety of compounds are examined. The effects of the disorder at nano-level on the landscape at the bottom of the conduction band, which is adjacent to the band gap, have been discussed. The ways to control the composition of polycationic compounds when creating precursors, the role of disorder in the anionic sublattice in alkali halide compounds, a positive role of Gd based matrices on scintillation properties, and the control of the heterovalent state of the activator by creation of disorder in silicates have been considered as well. The benefits of introducing a 3D printing method, which is prospective for the engineering and production of scintillators at the nanoscale level, have been manifested.

Wormlike surfactant micelles are widely used in various applications including fracturing technology in oil industry, template synthesis of different nanoobjects, micellar copolymerization of hydrophilic and hydrophobic monomers, and so forth. Most of those applications suggest the solubilization of different additives in the micelles. The present paper is aimed at the comparative study of the effect of the solubilization of hydrophobic (n-decane and 1-phenylhexane) and hydrophilic (N-isopropylacrylamide and acrylamide) substances on the rheological properties and structure of the micelles using several complementary techniques including rheometry, small angle neutron scattering, dynamic light scattering, and diffusion ordered NMR spectroscopy. For these studies, mixed micelles of potassium oleate and n-octyltrimethylammonium bromide containing the excess of either anionic or cationic surfactants were used. It was shown that hydrophobic additives are completely solubilized inside the micelles being localized deep in the core (n-decane, 1-phenylhexane) or near the core/corona interface (1-phenylhexane). At the same time, only a small fraction of hydrophilic additives (14% of N-isopropylacrylamide and 4% of acrylamide) penetrate the micelles being localized at the corona area. Despite different localization of the additives inside the micelles, all of them induce the breaking of wormlike micelles with the formation of either ellipsoidal microemulsion droplets (in the case of hydrophobic additives) or ellipsoidal surfactant micelles (in the case of hydrophilic additives). The breaking of micelles results in the drop of viscosity of the solution up to water value. The main result of this paper consists in the observation of the fact that for all the additives under study, the dependences of the viscosity on the volume fraction of additive lie on the same master curve being shifted along the volume fraction axis by a certain factor depending on the hydrophobicity of the added species. Those data are quite useful for various applications of wormlike surfactant micelles suggesting the solubilization of different additives inside them.

Highly efficient oxidation of isopropylbenzene mediated by the system of NHPI/Fe(acac)3/Phen has been carried out at temperature as low as 60 °C. Significant improvement of catalysis by NHPI was associated with an enhanced oxidizing ability of Fe(III) tandem with Phen, which caused the intense generation of PINO. Furthermore, NMR observations revealed formation of a hydrogen-bonded NHPI-Phen adduct soluble in acetonitrile and isopropylbenzene. Based on this phenomenon, the system was applicable for the oxidation of solvent-free isopropylbenzene. The promise of the system of NHPI/Fe(acac)3/Phen for the selective synthesis of isopropylbenzene hydroperoxide was demonstrated by oxidation at a low content of Fe(acac)3.

A set of novel 2′-deoxyuridine-5′-triphosphate (dUTP) derivatives modified with tyrosine (Tyr) or tryptophan (Trp) aromatic groups (m-dUTP) was tested as bearers of electroactive ‘labels’ for double-stranded DNA (dsDNA) detection as well as proper substrates for use in recombinase polymerase amplification (RPA). The ‘labeled’ dUTP have demonstrated oxidation peaks at 0.50–0.65 V, similar to free Tyr or Trp. Among five m-dUTP tested in this study, merely two nucleotides modified with Tyr aromatic groups revealed good compatibility with RPA. The modified dsDNA amplicons, generated by RPA, have been detected at micromolar concentrations via the oxidation of electroactive ‘labels’, while no signals were registered under the same conditions for the control unmodified dsDNA. Therefore, the developed dUTP derivatives with Tyr aromatic groups appear as promising recombinase substrates for a further elaboration of on-site electrochemical assays for medical, ecological, or agricultural applications.

A classical molecular dynamics (MD) model of fully unconstrained layered double hydroxide (LDH) particles in aqueous NaCl solution was developed to explore the initial stages of the anion exchange process, a key feature of LDHs for their application in different fields. In particular, this study focuses on the active corrosion protection mechanism, where LDHs are able to entrap aggressive species from the solution while releasing fewer corrosive species or even corrosion inhibitors. With this purpose in mind, it was explored the release kinetics of the delivery of nitrate and 2-mercaptobenzothiazole (MBT, a typical corrosion inhibitor) from layered double hydroxide particles triggered by the presence of aggressive chloride anions in solution. It was shown that the delamination of the cationic layers occurs during the anion exchange process, which is especially evident in the case of MBT−.

This paper presents a comprehensive study of the energy structure, optical characteristics, and spectral-kinetic parameters of elementary excitations in a high-purity nanocrystalline cubic Y2O3 film synthesized by reactive magnetron sputtering. The optical transparency gaps for direct and indirect interband transitions were determined and discussed. The dispersion of the refractive index was established based on the analysis of interference effects. It was found that the refractive index of the Y2O3 film synthesized in this study is higher in order of magnitude than that of the films obtained with the help of other technologies. The intrinsic emission of Y2O3 film has been discussed and associated with the triplet–singlet radiative relaxation of self-trapped and bound excitons. We also studied the temperature behavior of the exciton luminescence of Y2O3 for the first time and determined thermal activation barriers. The optical energy and kinetic parameters of cubic Y2O3 films were analyzed in comparison with those of the monoclinic films of yttrium oxide. The main difference between the optical properties of cubic and monoclinic Y2O3 films was established, which allowed for a supposition of their application prospects.

It has been shown that the cultivation of plants under glass coated with nano-sized upconversion luminophores led to an increase in plant productivity and the acceleration of plant adaptation to ultraviolet radiation. In the present work, we examined the effect of upconversion nanopowders with the nominal composition Sr0.955Yb0.020Er0.025F2.045 on plant (Solanum lycopersicum) photochemistry. The composition, structure and size of nanoparticles were tested using X-ray pattern diffraction, scanning electron microscopy, and dynamic light scattering. Nanoparticles are capable of converting infrared radiation into red and green photons. Glasses coated with upconversion luminophores increase the intensity of photosynthetically active radiation and absorb the ultraviolet and far-red radiation. The chlorophyll a fluorescence method showed that plants growing under photoconversion and those growing under common film demonstrate different ability to utilize excitation energy via photosynthesis. It was shown that under ultraviolet and high light conditions, the efficiency of the photochemical reactions, the non-photochemical fluorescence quenching, and the electron transport remained relatively stable in plants growing under photoconversion film in contrast to plants growing under common film. Thus, cultivation of Solanum lycopersicum under photoconversion glasses led to the acceleration in plant growth due to greater efficiency of plant photochemistry under stress conditions.

Owing to a strong photothermal response in the near-IR spectral range and very low toxicity, titanium nitride (TiN) nanoparticles (NPs) synthesized by pulsed laser ablation in liquids (PLAL) present a novel appealing object for photo-induced therapy of cancer, but the properties of these NPs still require detailed investigation. Here, we have elaborated methods of femtosecond laser ablation from the TiN target in a variety of liquid solutions, including acetonitrile, dimethylformamide, acetone, water, and H2O2, to synthesize TiN NPs and clarify the effect of liquid type on the composition and properties of the formed NPs. The ablation in all solvents led to the formation of spherical NPs with a mean size depending on the liquid type, while the composition of the NPs ranged from partly oxidized TiN to almost pure TiO2, which conditioned variations of plasmonic peak in the region of relative tissue transparency (670–700 nm). The degree of NP oxidation depended on the solvent, with much stronger oxidation for NPs prepared in aqueous solutions (especially in H2O2), while the ablation in organic solvents resulted in a partial formation of titanium carbides as by-products. The obtained results contribute to better understanding of the processes in reactive PLAL and can be used to design TiN NPs with desired properties for biomedical applications.

The ability of sixteen wood- and soil-inhabiting basidiomycete strains and four ascomycete strains to degrade the most hazardous, widespread, and persistent pollutants (polycyclic aromatic hydrocarbons, oxyethylated nonylphenol, alkylphenol, anthraquinone-type synthetic dyes, and oil) was found. The disappearance of the pollutants, their main metabolites, and some adaptive properties (activities of ligninolytic enzymes, the production of emulsifying compounds and exopolysaccharides) were evaluated. The toxicity of polycyclic aromatic hydrocarbons decreased during degradation. New data were obtained regarding (1) the dependence of the completeness of polycyclic aromatic hydrocarbon degradation on the composition of the ligninolytic enzyme complex; (2) the degradation of neonol AF9-12 by higher fungi (different accessibilities of the oxyethyl chain and the aromatic ring of the molecules to different fungal genera); and (3) the production of an emulsifying agent in response to the presence in the cultivation medium of hydrophobic pollutants as the common property of wood- and soil-inhabiting basidiomycetes and ascomycetes. Promise for use in mycoremediation was shown in the wood-inhabiting basidiomycetes Pleurotus ostreatus f. Florida, Schizophyllum commune, Trametes versicolor MUT 3403, and Trametes versicolor DSM11372; the litter-decomposing basidiomycete Stropharia rugosoannulata; and the ascomycete Cladosporium herbarum. These fungi degrade a wide range of pollutants without accumulation of toxic metabolites and produce ligninolytic enzymes and emulsifying compounds.

A new original copper nanocomposite based on poly-N-vinylimidazole was synthesized and characterized by a complex of modern physicochemical and biological methods. The low cytotoxicity of the copper nanocomposite in relation to the cultured hepatocyte cells was found. The possibility to involve the copper from the nanocomposite in the functioning of the copper-dependent enzyme systems was evaluated during the incubation of the hepatocyte culture with this nanocomposite introduced to the nutrient medium. The synthesized new water-soluble copper-containing nanocomposite is promising for biotechnological and biomedical research as a new non-toxic hydrophilic preparation that is allowed to regulate the work of key enzymes involved in energy metabolism and antioxidant protection as well as potentially serving as an additional source of copper.

The present paper addresses the problem of identification of microstructural, nanomechanical, and tribological properties of thin films of tantalum (Ta) and its compounds deposited on stainless steel substrates by direct current magnetron sputtering. The compositions of the obtained nanostructured films were determined by energy dispersive spectroscopy. Surface morphology was investigated using atomic force microscopy (AFM). The coatings were found to be homogeneous and have low roughness values (

The changes in the morphology and the electrophysical properties of the Cr/n-Si (111) structure depending on the rapid thermal treatment were considered in this study. The chromium films of about 30 nm thickness were deposited via magnetron sputtering. The rapid thermal treatment was performed by the irradiation of the substrate’s back side with the incoherent light flux of the quartz halogen lamps in nitrogen medium up to 200–550 °C. The surface morphology was investigated, including the grain size, the roughness parameters and the specific surface energy using atomic force microscopy. The resistivity value of the chromium films on silicon was determined by means of the four-probe method. It was established that at the temperatures of the rapid thermal treatment up to 350 °C one can observe re-crystallization of the chromium films with preservation of the fine grain morphology of the surface, accompanied by a reduction in the grain sizes, specific surface energy and the value of specific resistivity. At the temperatures of the rapid thermal treatment from 400 to 550 °C there originates the diffusion synthesis of the chromium disilicide CrSi2 with the wave-like surface morphology, followed by an increase in the grain sizes, roughness parameters, the specific surface energy and the specific resistivity value.

During the COVID-19 pandemic, the development of sensitive and rapid techniques for detection of viruses have become vital. Surface-enhanced Raman scattering (SERS) is an appropriate tool for new techniques due to its high sensitivity. SERS materials modified with short-structured oligonucleotides (DNA aptamers) provide specificity for SERS biosensors. Existing SERS-based aptasensors for rapid virus detection are either inapplicable for quantitative determination or have sophisticated and expensive construction and implementation. In this paper, we provide a SERS-aptasensor based on colloidal solutions which combines rapidity and specificity in quantitative determination of SARS-CoV-2 virus, discriminating it from the other respiratory viruses.

As in any other phase transition, hydrate phase transition kinetics involves an implicit coupling of phase transition thermodynamic control and the associated dynamics of mass and heat transport. This work provides a brief overview of certain selected hydrate film growth models with an emphasis on analyzing the hydrate phase transition dynamics. Our analysis is based on the fundamental properties of hydrate and hydrate/liquid water interfaces derived from molecular modeling. We demonstrate that hydrate phase transitions involving water-dominated phases are characterized by heat transport several orders of magnitude faster than mass transport, strongly suggesting that any hydrate phase transition kinetic models based on heat transport will be entirely incorrect as far as thermodynamics is concerned. We therefore propose that theoretical studies focusing on hydrate nucleation and growth should be based on concepts that incorporate all the relevant transport properties. We also illustrate this point using the example of a fairly simplistic kinetic model, that of classical nucleation theory (CNT), modified to incorporate new models for mass transport across water/hydrate interfaces. A novel and consistent model suitable for the calculation of enthalpies is also discussed and appropriate calculations for pure components and relevant mixtures of carbon dioxide, methane, and nitrogen are demonstrated. This residual thermodynamic model for hydrate is consistent with the free energy model for hydrate and ensures that our revised CNT model is thermodynamically harmonious.

Here we report on the development and investigation of a novel multiplex assay model based on polymer microspheres (PMS) encoded with ternary AIS/ZnS quantum dots (QDs). The system was prepared via layer-by-layer deposition technique. Our studies of Förster resonance energy transfer (FRET) between the QD-encoded microspheres and two different cyanine dyes have demonstrated that the QD photoluminescence (PL) quenching steadily increases with a decrease in the QD-dye distance. We have found that the sensitized dye PL intensity demonstrates a clear maximum at two double layers of polyelectrolytes between QDs and Dye molecules on the polymer microspheres. Time resolved PL measurements have shown that the PL lifetime decreases for the QDs and increases for the dyes due to FRET. The designed system makes it possible to record spectrally different bands of FRET-induced dye luminescence with different decay times and thereby allows for the multiplexing by wavelength and photoluminescence lifetimes of the dyes. We believe that PMS encoded with AIS/ZnS QDs have great potential for the development of new highly selective and sensitive sensor systems for multiplex analysis to detect cell lysates and body fluids’ representative biomarkers.

Ternary quantum dots (QDs) are very promising nanomaterials with a range of potential applications in photovoltaics, light-emitting devices, and biomedicine. Despite quite intensive studies of ternary QDs over the last years, the specific relaxation channels involved in their emission mechanisms are still poorly understood, particularly in the corresponding core-shell nanostructures. In the present work, we have studied the recombination pathways of AgInS2 QDs stabilized with the ZnAgInS alloy layer and the ZnS shell (AIS/ZAIS/ZnS QDs) using time-resolved fluorescence spectroscopy. We have also investigated FRET in complexes of AIS/ZAIS/ZnS QDs and cyanine dyes with the absorption bands overlapping in the different regions of the QD emission spectrum, which allowed us to selectively quench the radiative transitions of the QDs. Our studies have demonstrated that FRET from QDs to dyes results in decreasing of all QD PL decay components with the shortest lifetime decreasing the most and the longest one decreasing the least. This research presents important approaches for the investigation of ternary QD luminescence mechanisms by the selective quenching of recombination pathways. These studies are also essential for potential applications of ternary QDs in photodynamic therapy, multiplex analysis, and time-resolved FRET sensing.

Alteration of the phase composition of a coating and/or its surface topography can be achieved by changing the deposition technology and/or introducing additional elements into the coating. Investigation of the effect of the composition of CrN-based coatings (including AlCrN and CrON) on the microparticle height and volume, as well as the construction of correlations between the friction coefficient at the microscale and the geometry of microparticles, are the goals of this study. We use atomic force microscopy (AFM), which is the most effective method of investigation with nanometer resolution. By revealing the morphology, AFM allows one to determine the diameter of the particles, their heights and volumes and to identify different phases in the studied area by contrasted properties. The evaluation of the distribution of mechanical properties (modulus of elasticity E and microhardness H) on the surfaces of multiphase coatings with microparticles is carried out by using the nanoindentation method. It is found that the roughness decreases with an increase in the Al concentration in AlCrN. For the CrON coatings, the opposite effect is observed. Similar conclusions are valid for the size of the microparticles and their height for both types of coating.

Highly porous nitrogen-doped carbon nanomaterials have distinct advantages in energy storage and conversion technologies. In the present work, hydrothermal treatments in water or ammonia solution were used for modification of mesoporous nitrogen-doped graphitic carbon, synthesized by deposition of acetonitrile vapors on the pyrolysis products of calcium tartrate. Morphology, composition, and textural characteristics of the original and activated materials were studied by transmission electron microscopy, X-ray photoelectron spectroscopy, near-edge X-ray absorption fine structure spectroscopy, infrared spectroscopy, and nitrogen gas adsorption method. Both treatments resulted in a slight increase in specific surface area and volume of micropores and small mesopores due to the etching of carbon surface. Compared to the solely aqueous medium, activation with ammonia led to stronger destruction of the graphitic shells, the formation of larger micropores (1.4 nm vs. 0.6 nm), a higher concentration of carbonyl groups, and the addition of nitrogen-containing groups. The tests of nitrogen-doped carbon materials as electrodes in 1M H2SO4 electrolyte and sodium-ion batteries showed improvement of electrochemical performance after hydrothermal treatments especially when ammonia was used. The activation method developed in this work is hopeful to open up a new route of designing porous nitrogen-doped carbon materials for electrochemical applications.

Nowadays, multiplex analysis is very popular, since it allows to detect a large number of biomarkers simultaneously. Traditional multiplex analysis is usually based on changes of photoluminescence (PL) intensity and/or PL band spectral positions in the presence of analytes. Using PL lifetime as an additional parameter might increase the efficiency of multiplex methods. Quantum dots (QDs) can be used as luminescent markers for multiplex analysis. Ternary in-based QDs are a great alternative to the traditional Cd-based one. Ternary QDs possess all advantages of traditional QDs, including tunable photoluminescence in visible range. At the same time ternary QDs do not have Cd-toxicity, and moreover they possess long spectral dependent lifetimes. This allows the use of ternary QDs as a donor for time-resolved multiplex sensing based on Förster resonance energy transfer (FRET). In the present work, we implemented FRET from AgInS2/ZnS ternary QDs to cyanine dyes absorbing in different spectral regions of QD luminescence with different lifetimes. As the result, FRET-induced luminescence of dyes differed not only in wavelengths but also in lifetimes of luminescence, which can be used for time-resolved multiplex analysis in biology and medicine.

Novel silver/poly-1-vinyl-1,2,4-triazole nanocomposite materials—possessing antimicrobial activity against Gram-positive and Gram-negative bacteria—have been synthesized and characterized in the solid state and aqueous solution by complex of modern physical-chemical and biologic methods. TEM-monitoring has revealed the main stages of microbial cell (E. coli) destruction by novel nanocomposite. The concept of direct polarized destruction of microbes by nanosilver proposed by the authors allows the relationship between physicochemical and antimicrobial properties of novel nanocomposites. At the same time, it was shown that the nanocomposite was nontoxic to the fibroblast cell culture. Thus, the synthesized nanocomposite combining antibacterial activity against Gram-positive and Gram-negative bacteria as well as the absence of toxic effects on mammalian cells is a promising material for the development of catheters, coatings for medical devices.

Chemistry transport models (CTMs) are an indispensable tool for studying and predicting atmospheric and climate effects associated with carbonaceous aerosol from open biomass burning (BB); this type of aerosol is known to contribute significantly to both global radiative forcing and to episodes of air pollution in regions affected by wildfires. Improving model performance requires systematic comparison of simulation results with measurements of BB aerosol and elucidation of possible reasons for discrepancies between them, which, by default, are frequently attributed in the literature to uncertainties in emission data. Based on published laboratory data on the atmospheric evolution of BB aerosol and using the volatility basis set (VBS) framework for organic aerosol modeling, we examined the importance of taking gas-particle partitioning and oxidation of semi-volatile organic compounds (SVOCs) into account in simulations of the mesoscale evolution of smoke plumes from intense wildfires that occurred in western Russia in 2010. Biomass burning emissions of primary aerosol components were constrained with PM10 and CO data from the air pollution monitoring network in the Moscow region. The results of the simulations performed with the CHIMERE CTM were evaluated by considering, in particular, the ratio of smoke-related enhancements in PM10 and CO concentrations (ΔPM10 and ΔCO) measured in Finland (in the city of Kuopio), nearly 1000 km downstream of the fire emission sources. It is found that while the simulations based on a "conventional" approach to BB aerosol modeling (disregarding oxidation of SVOCs and assuming organic aerosol material to be non-volatile) strongly underestimated values of ΔPM10/ΔCO observed in Kuopio (by a factor of 2), employing the "advanced" representation of atmospheric processing of organic aerosol material resulted in bringing the simulations to a much closer agreement with the ground measurements. Furthermore, taking gas-particle partitioning and oxidation of SVOCs into account is found to result in a major improvement of the agreement of simulations and satellite measurements of aerosol optical depth, as well as in considerable changes in predicted aerosol composition and top-down BB aerosol emission estimates derived from AOD measurements.