In this study, we investigated the antimicrobial properties of graphene nanoribbons (GNRs) synthesized via a bottom-up approach. Due to their tendency to aggregate in aqueous solutions, various surfactants were used as stabilizers. We examined the effects of GNRs in combination with commonly used surfactants—including the cationic CTAB, anionic TWEEN, and non-ionic TRITON—to evaluate their impact on GNR toxicity. A range of GNR-surfactant concentrations was tested against biofilm-forming (Escherichia coli MG1655 and Staphylococcus epidermidis DSM 20044) and non-biofilm-forming (E. coli TOP10 and S. epidermidis BH1) bacterial strains under short-term (acute) and long-term (continuous) exposure conditions. CTAB alone exhibited antibacterial effects, but a synergistic interaction between CTAB and GNRs was observed during continuous exposure, particularly against Gram-positive bacteria. The capability to form biofilms did not significantly contribute to bacterial resistance, except in E. coli MG1655, which survived at the highest concentrations of GNR-CTAB during short-term exposure. In contrast to GNR-CTAB, GNR-TWEEN, and GNR-TRITON suspensions showed no inhibitory effects on bacterial growth and, in some cases, even promoted bacterial growth. Microscopic analysis revealed bacterial cell aggregation exclusively in GNR-CTAB suspensions. These findings highlight the critical role of surfactant selection in modulating GNR toxicity and provide insights into optimizing GNRs as antibacterial agents or minimizing their environmental impact.

The wide practical application of carbon nanomaterials (CNM) is limited by their potential ecological toxicity, various aspects of which remain debatable. This work assesses the effect of graphene oxide (GO) and multi-walled carbon nanotubes (MWCNTs) on the growth, viability, oxidative stress, and content of photosynthetic pigments in the cells of a common microalga of the genus Desmodesmus. The study shows differences in the effects of different carbon nanomaterials at the same concentrations. Thus, GO does not have a negative effect on the viability and cell growth of the microalga Desmodesmus armatus with the exception of an increase in the level of oxidative stress, which ultimately affects growth of the culture. At the same time, when MWCNTs are added at concentrations of 100 and 1000 μg/L, a significant decrease in the growth of the cell number is recorded already on the 7th day of the experiment, with the effect maintained at the end of the experiment (14th day). At the same concentrations, a significantly higher level of oxidative stress is observed on the 14th day of the experiment. The analyzed CNMs do not have a reliable effect on the content of photosynthetic pigments. Thus, in the studied concentrations, GO turns out to be practically safe for the studied microalgae, unlike MWCNTs, which show noticeable toxicity. This can be taken into account in the future when developing practical applications for such CNMs, and can also be used in environmental regulation of their content in the environment.

Currently, the development of technologies to improve the efficiency of existing micropropagation techniques remains relevant. This work contains the results of studying the effects of Ag nanoparticles (NPs) of spherical shape (20–40 nm) and CuO of flocculent morphology (diameter 50 to 200 nm, thickness 10–20 nm) on brittle willow plants and the assessment of their biological effects using the method of clonal micropropagation. At the multiplication stage, Ag and CuO NPs at a concentration of 3 μg/L increase the number of surviving and sterile microclones to 100

Biocarbon materials are attracting increasing interest from researchers due to their excellent sorption properties and environmental friendliness of their production. Having a developed internal surface, nanostructured biocarbon materials demonstrate record sorption characteristics. One of the promising areas of application of such sorbents is plant biotechnology. Thus, an important problem of clonal micropropagation in vitro is the need to remove metabolites toxic to seedlings, primarily phenolic compounds. Biocarbon sorbents, including nanobiochars, have demonstrated high efficiency in the adsorption of such contaminants, including when introduced into nutrient media for plant-tissue culture. Changing the conditions for the synthesis of biocarbon nanomaterials directly affects their sorption characteristics, which opens up opportunities for the targeted production of optimal sorbents for intensifying and reducing the cost of the clonal micropropagation of plants. At the same time, uncertainty remains regarding the sorption and other properties of such promising materials as biographene and its derivatives when introduced as a component into media for plant-tissue culture. The mechanisms of the adsorption of phenolic compounds by carbon nanomaterials are not fully understood. There are concerns about the risks associated with the exposure of plants to nanoparticles and nanomaterials. All these questions require further research.

The study is the first to examine the combined use of blast-furnace sludge as a source of microelements and converter slag as a soil-deoxidizing agent in oat (Avena sativa L.) cultivation in sod-podzolic soils. It has been established that blast-furnace sludge is a highly dispersed waste, which contains about 50% iron, 7% zinc, and a small amount of calcium, silicon, magnesium, aluminum, and sulfur. Hazardous components such as lead, arsenic, etc., are not detected. Converter slag comprises porous granules up to 3 mm in size, consisting mainly of calcium compounds (CaO, Ca(CO)3, CaSiO3, CaFe2O4) and a small amount of Mn, Al, and Mg trace elements. In a laboratory experiment, blast-furnace sludge increased the germination of oats by 5–10%, regardless of the addition of a deoxidizer (slag), but at the same time suppressed the growth of stem length by a maximum of 18% at 1 g∙kg−1. The addition of slag raised substrate pH and increased the index by 8% at a sludge concentration of 0.1 g∙kg−1. Root length in deoxidizer-free variants increased by 50–60% and with the addition of slag by 27–47%. Root dry mass also increased under the addition of sludge by 85–98%; however, the addition of slag reduced the indicator to the control level. In a field experiment with the combined application of waste, an increase in yield by more than 30% was shown. When soil was treated with slag and sludge, the height of plants increased by an average of 18%. It should be noted that the introduction of waste did not affect the quality of the grain. The use of slag increased the lead content in the soil, which is probably due to the sorption properties of calcium compounds in the slag, since lead was not found in the analyzed waste. Presumably, lead is sorbed by slag from the lower soil horizons, concentrating and immobilizing it in the upper layer. This version is supported by the absence of lead accumulation in straw and oat grain. The zinc-containing sludge increased the content of this element by 33% in the soil, as well as by 6% in straw and by 14% in grain. Thus, we found that the studied metallurgical wastes can be used as nutrients for agriculture, both individually and jointly. Overall, the proposed approach will contribute both to reducing the amount of accumulated waste and to improving the efficiency and sustainability of agricultural production and CO2 sequestration. However, the features of the accumulation of heavy metals in soil and plants under the influence of the analyzed types of waste require more in-depth study, including within the framework of long-term field experiments.

The use of zero-valent iron nanoparticles in the remediation of metal-contaminated soils has received considerable attention. Upon introduction into the soil, zero-valent iron particles corrode into iron oxides, known for their high adsorption capacity for potentially toxic metals. While limited research has directly compared zero-valent iron micro- and nanoparticles, it is important to investigate whether particle size contributes to effective soil remediation. This study focuses on elucidating the comparative kinetics of iron corrosion using iron powder and a nano-iron-biochar composite. In a model experiment, these materials were exposed to a cellulose/biochar mixture and peat for five months. Mössbauer spectroscopy, X-ray diffraction, scanning electron microscopy with energy dispersive X-ray spectroscopy, and transmission electron microscopy with electron diffraction were used to analyze the corrosion products. The results show a slow corrosion rate in the nano-iron-biochar composite in cellulose due to the protective effect of biochar on the embedded iron nanoparticles. In addition, iron corrosion in peat was inhibited, likely due to the presence of humic substances. Transmission electron microscopy after five months of corrosion revealed round metal particles encased in a graphite capsule with visible channels. Large dissolved organic matter molecules in the peat likely block these channels, inhibiting metallic iron corrosion. Consequently, the nano-iron-biochar composite emerges as a slow-reacting option for immobilizing soil metals in peat. This study highlights the need for further research involving long-term field experiments.

Using the dynamic mechanical analysis (DMA) method with the application of a harmonic oscillating load, the elastic modulus E' , loss modulus E ", and loss tangent tgδ in the microstructure of beech wood ( Fagus orientalis ) were determined. It was found that in the range of 0.01-66.66 Hz, no frequency dependence of all three studied characteristics was observed within the accuracy of the experiment. At the same time, the dependence of the elastic modulus E' on the static stress was established.

The paper presents the results of scanning of mechanical properties of coniferous (common pine Pinus sylvestris) and deciduous (small-leaved lime Tilia cordata and common oak Quercus robur) trees wood using naation on crosscut face. Manifold increase in microhardness H and Young's modulus E has been observed between early and late wood in every annual growth ring. Significant differences in intraring radial dependencies of H and E have been found among studied species. For all studied species the average values of E and H of early wood in each annual ring are found to be independent from ring width, while such dependence for late wood is weak at most. The ring widths measured by naation coincide with the ones measured by standard optical method within 2-3%. The developed technique and obtained results can be useful 1) to amend the understanding the origins of macromechanical properties of various wood species and their dependence upon microstructural characteristics and growth conditions, 2) to optimize the technologies of growing, reinforcement and subsequent usage of the wood, 3) to develop new independent high resolution methods in dendrochronology. Keywords: naation, nano-/microhardness and Young's modulus scanning, tree annual growth rings, dendrochronology.

Oak is an important tree species, playing a fundamental role in many forest ecosystems. Obtaining high-quality oak planting material is a actual issue in forest biotechnology. The most promising method for this, in vitro micropropagation, faces a number of problems that can be overcome using a nanobiotechnological approach. In our work, we obtained flaky copper oxide nanoparticles with a particle size of 50–200 nm in diameter and a thickness of 10–20 nm, which were used in the WPN medium at a concentration of 0.75, 1.5, 3, 6, and 15 μg L-1 at the stage of introducing the original red oak material into the in vitro tissue culture. The study demonstrated a dose-dependent antimicrobial effect: seedling sterility increased from 80% (+10% to the control) at 1.5 μg L-1 CuO to 100% at doses of 3 μg L-1 and higher. The maximum survival rate was observed at 3 μg L-1 – 43%, which is 23% higher than the control values. At the multiplication stage, nanoparticles significantly increased plant viability – twice as much in the variant with 3 μg L-1 CuO and 1.7 times when using nanoparticles and phytohormones. The combined use of nanoparticles and hormones increased the seedling height by 1.5 times and the number of additional shoots by 3 times. At the rooting stage, CuO nanoparticles did not show any rhizogenesis-stimulating effect. At the same time, phytohormones and nanoparticles stimulated root formation. At the adaptation stage, a fairly low percentage of surviving and adapted plants was observed in the control variant, while the addition of nanoparticles had a positive effect on plant adaptation. The number of surviving seedlings increased by 15%, the number of adapted ones by 10. Thus, our study showed the prospects of using CuO nanoparticles to improve the biotechnology of clonal micropropagation of red oak. In the future, these results can be used in breeding and obtaining high-quality planting material for this species.

Using a small oscillating load (continuous stiffness measurement, CSM), in addition to the main quasi-static load, we determine the hardness, Young’s modulus, storage and loss moduli, mechanical loss coefficient ( tanδ ), and the plasticity characteristics in various components of the nanostructure and microstructure of pine (Pinus sylvestris) and spruce (Picea abies) wood. The contribution of structures of different scales to the ratio of the viscoelastic properties of early and late wood in the composition of one annual ring is determined. The plasticity characteristic δА is determined, and the influence of an additional oscillating load on the dynamic parameters of wood is assessed.

The paper presents the results of mechanical properties scanning by means of naation across the annual growth rings of deciduous trees wood, small-leaved lime (Tilia cordata) and common oak (Quercus robur) in particular. Significant variations in microhardness H and Young's modulus E radial dependencies have been found for any of the studied species. Results can be useful 1) to amend the understanding the nature of macromechanical properties of various wood species and to reveal the details of their formation depending upon microstructural characteristics, 2) to optimize the technologies of growing, reinforcement and subsequent usage of the wood, 3) to develop new independent methods in dendrochronology and dendroclimatology Keywords: nanocomposites, naation, nano-/microhardness and Young's modulus scanning, tree annual growth rings, dendrochronology

The removal of pollutants, including heavy metals, from the aquatic environment is an urgent problem worldwide. Actively developing nanotechnology areas is becoming increasingly important for solving problems in the field of the remediation of aquatic ecosystems. In particular, methods for removing pollutants using nanoparticles (NPs) are proposed, which raises the question of the effect of a combination of NPs and heavy metals on living organisms. In this work, we investigated the role of CuO-NPs in changing the toxicity of Cd and Pb salts, as well as the bioaccumulation of these elements in a culture of the microalga Desmodesmus communis. It was found that CuO-NPs at concentrations of 10, 100, and 1000 µg L−1 had no effect on the viability of microalgae cells. On the 14th day of the experiment, Cd at a concentration of 1 mg L−1 reduced the viability index by 30% and, when combined with CuO-NPs, by 25%, i.e., CuO-NPs slightly reduced the toxic effect of Cd. At the same time, in this experiment, when CuO-NPs and Cd were used together, the level of oxidative stress increased, including on the first day in mixtures with 1 mg L−1 Cd. Under the influence of Pb, the cell viability index decreased by 70% by the end of the experiment, regardless of the metal concentration. The presence of CuO-NPs slightly reduced the toxicity of Pb in terms of viability and reactive oxygen species (ROS). At the same time, unlike Cd, Pb without NPs caused ROS production on the first day, whereas the addition of CuO-NPs completely detoxified Pb at the beginning and had a dose-dependent effect on mixtures at the end of the experiment. Also, the introduction of CuO-NPs slightly reduced the negative effect of Pb on pigment synthesis. As a molecular mechanism of the observed effects, we prioritized the provocation of oxidative stress by nanoparticles and related gene expression and biochemical reactions of algae cells. Analysis of the effect of CuO-NPs on the Cd and Pb content in microalgae cells showed increased accumulation of heavy metals. Thus, when algae were cultured in an environment with Cd and CuO-NPs, the Cd content per cell increased 4.2 times compared to the variant where cells were cultured only with Cd. In the case of Pb, the increase in its content per one cell increased 6.2 times when microalgae were cultured in an environment containing CuO-NPs. Thus, we found that CuO-NPs reduce the toxic effects of Cd and Pb, as well as significantly enhance the bioaccumulation of these toxic elements in the cells of D. communis microalgae. The results obtained can form the basis of technology for the nanobioremediation of aquatic ecosystems from heavy metals using microalgae.

Pyroxene glass-ceramic enamels based on combinations of blast furnace slag and some additives were produced and investigated. The batch compositions and technological regimes of enameling were developed to produce high temperature protective coatings for carbon steel (ASTM 1010/1008). The composition of raw materials was selected to match the values of the thermal expansion coefficients of the glass-ceramic coating (~11∙10−6 K−1) and metal substrate (~12∙10−6 K−1) taking into account the temperatures of fluidization (Tf ~ 800°) and crystallization (Tc = 850−1020 °C) of the corresponding glasses. The covered and thermally treated samples of carbon steel were produced using single-layer enameling technology and investigated to specify structure, phase composition and properties of the coating and coating-steel interface. The obtained coatings were characterized with excellent adhesion to the steel (impact energy ~3 J) and protective properties. The closed porous structure of the coatings promoted low thermal conductivity (~1 W/(m·K)) and high (up to 1000 °C) thermal resistance, whereas the pyroxene-like crystalline phases supported high wear and chemical resistance as well as micro-hardness (~480 MPa) and thermal shock resistance (>30 cycles of 23–700 °C). The obtained cheap coatings and effective protective coatings could be used at the temperatures up to 1100 °C in the corrosive atmosphere and under the action of abrasive particles.

In this work, we present an analysis of the antibacterial activity of TiS3 nanostructures in water and 0.9% NaCl solution suspensions. TiS3 nanoribbons 1–10 µm long, 100–300 nm wide, and less than 100 nm thick were produced by the direct reaction of pure titanium powder with elemental sulphur in a quartz tube sealed under vacuum. For the toxicity test of a bioluminescent strain of E. coli we used concentrations from 1 to 0.0001 g L−1 and also studied fresh suspensions and suspensions left for 24 h. The strongest toxic effect was observed in freshly prepared water solutions where the luminescence of bacteria decreased by more than 75%. When saline solution was substituted for water or when the solutions were stored for 24 h it resulted in a considerable decrease in the TiS3 antibacterial effect. The toxicity of TiS3 in water exceeded the toxicity of the reference TiO2 nanoparticles, though when saline solution was used instead of water the opposite results were observed. In addition, we did not find a relationship between the antibacterial activity of water suspensions of nanoribbons and the stability of their colloidal systems, which indicates an insignificant contribution to the toxicity of aggregation processes. In 0.9% NaCl solution suspensions, toxicity increased in proportion to the increase in the zeta potential. We suppose that the noted specificity of toxicity is associated with the emission of hydrogen sulphide molecules from the surface of nanoribbons, which, depending on the concentration, can either decrease or increase oxidative stress, which is considered the key mechanism of nanomaterial cytotoxicity. However, the exact underlying mechanisms need further investigation. Thus, we have shown an important role of the dispersion medium and the period of storage in the antibacterial activity of TiS3 nanoribbons. Our results could be used in nanotoxicological studies of other two-dimensional nanomaterials, and for the development of novel antibacterial substances and other biomedical applications of this two-dimensional material.

Amino- and carboxyl-functionalized carbon quantum dots (Amino-CQDs) were synthesized through fast and simple microwave treatment of a citric acid, ethylenediamine and ethylenediaminetetraacetic acid (EDTA) mix. The reproducible and stable optical properties from newly synthesized CQD dispersion with a maximum absorbance spectra at 330 nm and the symmetric emission maximum at 470 nm made the Amino-CQDs a promising fluorescence material for analytical applications. The highly aminated and chelate moieties on the CQDs was appropriate for a copper (Cu2+) cation sensor in the linear range from 1 × 10−4 mg/mL to 10 mg/mL with a limit of detection at 0.00036 mg/mL by static fluorescence quenching effects. Furthermore, Amino-CQDs demonstrated stable fluorescence parameters for assays in diluted alkali metal solution (Na+ and K+) and sea water. Finally, a visual sensor, based on Amino-CQDs, was successfully created for the 0.01–100 mg/mL range to produce a colorimetric effect that can be registered by computer vision software (Open CV Python).

The most widespread approach in dendrochronology (wood dating) and dendroclimatology (climate reconstruction) is based on measurement of the width of annual growth rings by analyzing optical images of wood cross sections. This approach is quite efficient and easy to implement but it has inherent drawbacks. Raw data for these techniques originate from the optical properties of the wood surface, which are not directly related to other properties of wood, mechanical properties in particular. This paper describes a new quantitative approach applicable to dendrochronology and dendroclimatology based upon measurement of the micromechanical properties of wood by employing nanoindendation and digital sclerometry. It yields not only the width of annual growth rings and early and late wood layers with an accuracy not inferior to optical methods, but also rich data on the mechanical properties of the wood with a high spatial resolution that could be brought to subcellular scale if necessary. This data can be used for the dendrochronological analysis of archeological finds and the evaluation of climatic parameters during tree growth with a time resolution of up to a month or even better, which is unlike other common methods with a time resolution of one year. Moreover, the detailed continuous profiling of local mechanical properties can form a basis for improving our understanding of the nature and mechanisms of the formation of macromechanical properties important for applications and can clarify the climate factors that have the greatest impact on such properties.

The xerogels based on the aqueous solutions of urea in potassium silicate liquid glass (PSLG) were produced by CO2 bubbling and investigated. The structure and chemical composition of the obtained materials were analyzed. Using the SEM, XRD, IR-FT, DSC, and low energy local EDS analysis, it was recognized that the dried gels (xerogels) contained three forms of urea: oval crystals of regular shape appeared onto the surface of xerogel particles; fibrous crystals were located in the silicate matrix; and molecules/ions were incorporated into the silicate matrix. It was shown that an increase in [(NH2)2CO] in the gel-forming system promoted increased contents in crystalline forms of urea as well as the diameter of the fiber-shaped urea crystals. A rate of the urea release in water from the granulated xerogels containing 5.8, 12.6, and 17.9 wt.% of urea was determined by the photometric method. It was determined that the obtained urea-containing xerogels were characterized with a slow release of urea, which continued up to 120 days, and could be used as controlled release fertilizers containing useful nutrients (N, K).

The paper presents the results of creep measurement in common pine wood at different scales ranging from nano to macro by means of continuous nanoindentation. It is shown that wood structure elements pertaining to different scale levels make different contribution to steady creep rate.

The paper presents the results of creep measurement in common pine wood at different scales ranging from nano to macro by means of continuous naation. It is shown that wood structure elements pertaining to different scale levels make different contribution to steady creep rate. Keywords: naation, wood, creep.