Bacterial isolates from the samples of Orostachys spinosa (L.) growing in the Baikal region were identified and studied. A total of 16 strains with different morphotypes were obtained, and their generic affiliation was determined by 16S rRNA sequencing. The antagonistic activity was confirmed for most strains belonging to the genus Bacillus. The most pronounced antagonism was exhibited by the strains 117B1–117B5, 117BA, and 117BE, which suggests their possible use as biological control agents against fungal phytopathogens. The ability to synthesize bacterial auxins was expressed in all the studied strains, but at a comparatively low level. The ability to fix atmospheric nitrogen under aerobic conditions was revealed in 14 of the 16 strains. The ability to mobilize phosphorus from calcium salt of phytic acid was found in 11 strains. The highest phosphorus mobilizing activity was observed in representatives of the genus Pseudomonas, particularly in the strains 117B7, 117B9, 117BB, and 117BD. Representatives of the genus Bacillus (the strains 117B1, 117B3, 117B4, 117B5, 117B8, and 117BE) had strong cellulase activity. The greatest ability to degrade cellulose was demonstrated by the strain Bacillus sp. 117BA. The findings indicate that the strains Bacillus sp. 117BA and 117BE and Pseudomonas sp. 117BB and 117BD are promising candidates for the development of new biopreparations.
The radioprotective effects of copper chlorophyllin, riboxin, indralin, and the combined use of glutathione and ascorbic acid were compared in male ICR (CD-1) mice exposed to five daily irradiations at doses of 1.4 or 2.5 Gy, with all compounds administered on the days of irradiation. The radioprotective efficacy was assessed three days following the final exposure using hematological parameters, thymus and spleen weights, number of nucleated cells in the bone marrow of the femur, and content of thiobarbituric acid reactive substances (TBARS) in the liver. Riboxin, administered at 200 µg/g after each irradiation, showed contradictory effects in the TBARS test, increasing oxidative stress at 1.4 Gy and suppressing it at 2.5 Gy. Copper chlorophyllin was as efficient in inhibiting the metabolism of lipid radiotoxins as classical antioxidants, glutathione and ascorbic acid. In certain cases, the compounds exhibited an ability to somewhat alleviate radiation-induced pancytopenia. Indralin, an emergency radioprotector, had no consistent radioprotective superiority across the assessed physiological parameters of mice under fractionated irradiation. The ambiguity of the observed effects highlights the need for further comprehensive research to clarify the influence of the analyzed compounds on the course of radiation sickness under various experimental conditions.
Haloxylon aphyllum (Minkw.) Iljin is a shrub or small tree commonly used in agroforestry and desertification control in arid territories of southern Russia. To date, adaptive reactions at the physiological and biochemical level, particularly those associated with the photosynthetic apparatus and the content of metabolites in green shoots, and their relation to antioxidant properties remain poorly studied. Analysis of the genetic structure of various populations using DNA markers is also of considerable interest. In this study, the content of chlorophylls, carotenoids, and phenolic antioxidants in the green shoots of H. aphyllum was assessed, and the most informative ISSR primers were identified to examine the genetic structure of H. aphyllum populations. The experiments were conducted in 2024 with H. aphyllum samples collected in the Kharabalinsky district of the Astrakhan region. The ISSR primers UBC809, UBC810, UBC811, UBC818, UBC826, UBC834, UBC840, UBC846, UBC855, UBC860, UBC887, and UBC890 were found to be suitable for ISSR analysis of the genetic diversity of H. aphyllum populations. The original data on the content of photosynthetic pigments and metabolites with antioxidant properties in the green shoots of H. aphyllum were presented.
A comparative analysis was carried out to explore the co-expression networks of the SLC34A2 gene, which encodes the sodium-dependent phosphate transporter NaPi2b, with glycosyl-and sulfotransferase genes and the interaction between the products of these genes in ovarian normal and tumor cells in order to identify proteins responsible for aberrant glycosylation of the NaPi2b transporter in malignant cell transformation. Data on the expression of 214 glycosyl-and sulfotransferase genes and the SLC34A2 gene in ovarian normal and tumor cells were obtained from the E-MTAB-3732 dataset (ArrayExpress, n = 579), and data on 7025 protein-protein interactions were sourced from open-access databases. The networks constructed using the collected data revealed differences in the patterns of gene co-expression and the interaction of their products. The cophenetic correlation coefficient of the networks in ovarian normal and tumor cells was 0.17. The key genes B3GNT2, GCNT1, ST3GAL1, and ST6GAL1 were found to be part of the largest module together with SLC34A2 in the network of gene co-expression and protein-protein interactions in ovarian tumor cells. The results suggest that the expression and interaction profiles of ST6GAL1, B3GNT2, GCNT1, and ST3GAL1 gene products may be associated with abnormal glycosylation of NaPi2b in ovarian tumor cells. Further research on these proteins will foster a better understanding of the role of glycosylation in conformational changes of the large extracellular domain of the NaPi2b transporter and may contribute to the development of anti-tumor drugs targeting the potential tumor-specific MX35 epitope of the NaPi2b transporter.
The physical characteristics of three peanut (Arachis hypogaea L.) varieties grown in Vietnam differed significantly. The RP seeds had the highest moisture level (3.9 % RP, 2.9 % SP, 3.7 % BP). The SP variety showed the highest mass per 1000 seeds (474 g RP, 599 g SP, and 541 g BP). The bulk and particle densities of all the varieties ranged from 0.633 to 0.664 g/cm3 and from 1.10 to 1.14 g/cm3, respectively. The RP seeds were relatively larger based on their length (18.2 mm), width (9.0 mm), and thickness (8.7 mm). In terms of sphericity (0.62 RP, 0.62 SP, and 0.65 BP), the BP seeds were rounder in shape. The angle of repose was higher in the SP seeds (28 degrees RP, 28.1 degrees SP, 20 degrees BP). The BP seeds had higher static friction coefficient values (0.37 RP, 0.35 SP, 0.40 BP). These findings highlight the need to adapt standard peanut cultivation, processing, storage, and transportation methods to each peanut variety in order to increase the efficiency of local and global peanut-based production and reduce its potential losses.
The biological effects of low concentrations of Bisphenol A, a known inducer of oxidative stress, were evaluated in an in vitro experiment using & Ncy;& iecy;pG2 cells. With this aim, & Ncy;& iecy;pG2 cells were exposed to 0.10, 0.25, 0.50, and 1.0 mu M Bisphenol A for 48 and 72 h and then studied for their viability (via MTT assay) and oxidative stress based on the content of protein and non-protein SH groups, the protein carbonyl content, and the expression of the transcription factor NRF2 and the antiapoptotic protein BCL-2. The levels of NRF2 and BCL-2 remained unchanged after 48 h of exposure but increased following 72 h of incubation. This increase was accompanied by a rise in the concentration of thiol groups and the stabilization of the protein carbonyl content, suggesting the formation of a molecular mechanism protecting & Ncy;& iecy;pG2 cells from the xenobiotic action. The findings demonstrate that low concentrations of Bisphenol A have no pronounced effect on the viability of & Ncy;& iecy;pG2 cell line.
The molecular mobility of ibuprofen and ketoprofen, two active ingredients of nonsteroidal anti-inflammatory drugs, was examined. All calculations were performed by the DFT method in the isolated molecule approximation using the BP86 functional in combination with the def2-SVP basis set. The potential energy surface profiles for rotation around the C–C bond in key structural fragments of ibuprofen and ketoprofen were obtained. For both compounds, the preferred conformers and intramolecular rotation barriers were determined. The most stable conformers showed a good agreement between the experimental and calculated parameters of the molecular geometry. Linear correlations were observed between the experimental Raman spectra of ibuprofen and ketoprofen and the harmonic vibrational frequencies of their most stable conformers calculated at the BP86/def2-SVP level of theory, suggesting that this approach may be useful for further investigation of the structure and properties of ibuprofen and ketoprofen.
Rhizobacteria synthesizing indole-3-acetic acid (IAA) are often used to stimulate plant growth. To enhance IAA production by the rhizospheric bacterium Pseudomonas baetica MGMM504 during the growth on a tryptophan medium, a plasmid encoding naphthalene 1,2-dioxygenase synthesis genes (EC 1.14.12.12) was introduced. The expression of naphthalene 1,2-dioxygenase genes increased IAA synthesis in P. baetica MGMM504(pJeM2:nahA) by 40 % compared with the control. At the same time, P. putida PCL1760(pJeM2:nahA) showed no significant increase in IAA synthesis compared with PCL1760(pJeM2), which produced only trace amounts of IAA. The tests on wheat revealed a higher plant growth stimulating activity of P. baetica MGMM504(pJeM2:nahA), increasing the root length and germination of wheat seedlings by 45 % and 15 %, respectively, compared with P. baetica MGMM504(pJeM2). Neither variant of P. putida PCL1760 exhibited a phytostimulatory effect. The findings suggest that naphthalene 1,2-dioxygenase promotes the formation of an intermediate, which in itself is not a phytostimulator, but can be converted into one if a specialized IAA synthesis system is present in the strain.
The protection and sustainable use of groundwater resources require continuous monitoring and forecasting of both natural and anthropogenic pollutants accumulated in them. However, due to a lack of analytical data, a reliable assessment of these and other trends in the development of indicators necessary for making appropriate management decisions remains a great challenge. Even in a megalopolis such as Moscow, time series of data from available observation wells are limited to 10-20 members, which underscores the inefficiency of traditional statistical research methods. To solve the above problem, this article proposes an expert statistical exploratory data analysis (EDA) approach based on graphical visualization of statistical results and, compared to traditional methods, less dependent on the amount of experimental data. Using data obtained from the observation wells of the Teplostanskaya Upland in the Southwest Administrative District of Moscow during 2018-2023, statistical heterogeneity was established in the time series of groundwater composition and properties, eliminating randomness in the formation ofdata and indicating the presence ofhidden patterns in theirchange, mutually consistent variability was detected among certain pairs of groundwater pollutants, the possibility of identifying the origin (natural or anthropogenic) of individual groundwater components was demonstrated, and the feasibility of reducing the number of variables in a set of controlled indicators through the application of principal component analysis (PCA), accounting for 72 % of the variance in the problem under consideration, was shown. Since all measurements were carried out using a set of spatially separated wells, the experimental data were studied by common panel analysis method.
The adverse effects ofpolychlorinated biphenyls (PCBs) on human and animal health pose a significant concern. However, to date, most studies have considered the risks of environmental contamination by highly chlorinated biphenyls. This study, on the contrary, focuses on the impact of dichlorinated biphenyl (PCB 8) and its bacterial transformation products on the immune system. PCB 8 was found to suppress antibody formation without affecting cell-mediated immunity responses. The degradation of PCB 8 by Rhodococcus opacus FG1 reduced its impairment of humoral immunity. The bacterial transformation by Rhodococcus opacus FG1(VKMAc-3030) enzymes induced a 16.9-fold decrease in the PCB 8 concentration over 14 days. Concurrently, 2-chlorobenzoic acid (2-CBA) and 4-chlorobenzoic acid (4-CBA) accumulated in the medium. The assessment of the immune parameters following the exposure to 2-CBA and 4-CBA revealed no negative changes. The data from the health risk assessment demonstrated that, despite the observed decrease in the PCB 8 concentration during biotransformation, the non-carcinogenic risk remained high for both children and adults, whereas the carcinogenic risk declined to acceptable and safe levels for children and adults, respectively, by day 14. The calculated non-carcinogenic risk values from the resulting CBAs were not associated with health hazards.
The introduction of hybrid nanocomposites with graphene particles in which surfaces are modified by nano-dispersed SiO2 significantly improves the thermal stability of siloxane materials. By carbonizing rice husk using a tailored method of self-propagating high-temperature synthesis, a hybrid nanocomposite, low-layer graphene/SiO2, was obtained. Upon the incorporation of carbonized starch and carbonized rice husk into rubber mixtures based on polydimethylsiloxane, the vulcanization proceeded at an increased rate with a longer induction period. The resulting experimental mixtures were used to produce rubber samples subjected to physical and mechanical testing before and after thermal aging for 72 h at 250 degrees C in order to determine their elastic and strength characteristics. Overall, the outcomes of these tests confirm the effectiveness of the synthesized additives as thermal stabilizers for siloxane rubbers.
Collagen–pectin–methyl methacrylate copolymers were synthesized in an acetic acid dispersion in the presence of a triethylboron amine complex. The synthesis temperature was found to have little effect on the copolymer composition, while its morphology changed significantly. By using the amine complex in combination with p-quinone during the synthesis of collagen–pectin–methyl methacrylate copolymers, it was possible to vary the copolymer composition, the molecular weight of grafted polymethyl methacrylate, and the resulting morphology depending on the structure of the p-quinone used. Hydrogels based on the synthesized copolymers were formed in the presence of glutaric aldehyde. Their moisture-absorbing properties and stability in buffer solutions make them promising base materials for regenerative medicine. The absence of cytotoxicity and the stimulatory effect of the obtained materials on the growth of human dermal fibroblasts were demonstrated by the MTT assay. The analysis of biocidal activity indicates that collagen–pectin–methyl methacrylate hydrogels have a clear potential as fungusresistant bactericidal materials.
The geometry and structure of hollow fiber membranes fabricated from polysulfone by the dry-wet phase inversion method were studied with the help of scanning electron microscopy. Various amine hardeners and difunctional polyetheramines were analyzed as potential components of sealing compounds. The fabricated hollow fiber membranes were sealed in model membrane modules using epoxy sealing compounds with different hardeners. The applicability of these materials was assessed based on the presence of defects when gases were supplied under pressure at the contact point between the membrane and the epoxy. The use of polyetheramine as an amine hardener for the epoxy systems caused no defects at the point of contact between the hollow fiber membranes and the epoxy compound, even when pressures up to 0.5 atm were applied. This ensures high selectivity values for the He/N2 gas pair in the resulting membrane modules.
Polyethylene terephthalate (PET) film has good dielectric properties but high radiation-induced conductivity, which can be reduced by doping commercially available electrical insulation films with small electron-trapping molecules. This study investigates the doping process of PET-CE capacitor film (State Standard 24234-80) using fluorenone-based dopants, such as 2,7-dinitro-9-fluorenone (DNF) and 2,5,7-trinitro-9-fluorenone (TNF), and focusing on the role of the solvent (ethylene glycol and benzyl alcohol). The optimal doping temperature range was selected to be between the glass transition temperature of the doping polymer (88 degrees & Scy; for PET, lower limit) and the boiling point of the solvent (upper limit). The appropriate solvent and dopant solution concentrations were determined. Based on the experimental results, ethylene glycol and benzyl alcohol were selected as solvents for TNF and DNF, respectively. The following solvent selection criteria for doping systems were established: high boiling point, high dopant solubility, and low affinity for the polymer matrix.
The effect of treatment of polyphenylene sulfone (PPSU) and polysulfone (PSU) hollow fiber membranes with superheated water steam under autoclaving conditions for 270 h was investigated for the first time. The resistance of these membranes to repeated steam sterilization, a key parameter for their application in the purification of media that may contain pathogenic organisms, was evaluated. PPSU membranes were found to exhibit high thermal stability and resistance to hydrolysis and retain their functional characteristics after multiple sterilization cycles. The obtained data underscore the potential of PPSU as a promising material for creating durable and reliable hollow fiber membranes to carry out processes that necessitate the use of repeated sterilization.
The effect of adding 1,4-dioxane to casting solutions based on poly(acrylonitrile-co-methyl acrylate) (poly(AN-co-MA)) using solvents such as dimethyl sulfoxide (DMSO) and N-methylpyrrolidone (NMP) was investigated. The introduction of the soft precipitant altered the rheological properties of the studied solutions: it reduced viscosity in the poly(AN-co-MA)/NMP system and caused an opposite change in the poly(AN-co-MA)/DMSO system. A direct correlation was established between the solution viscosity and the deposition rate during membrane formation via phase inversion. The incorporation of 1,4-dioxane enabled controlled modification of the membrane morphology and filtration performance by reducing the average pore size. The reduction in the average pore size was more pronounced in the membranes with NMP than in the membranes with DMSO (up to 11.8 nm and 19.1 nm, respectively). During the filtration of crude oil and 100 g/L oil solution in toluene, the rejection of asphaltenes by the membranes of both types was over 98 %. These findings confirm the potential of 1,4-dioxane in the development of membranes with tailored properties for application in the petrochemical industry.
This article examines the effect of few-layer graphene (FLG) at different compositions on the strength, wear resistance, and thermal conductivity of epoxy resin. The FLG composition was varied using ammonium nitrate and potassium nitrate as synthesis precursors. The incorporation of FLG enhanced the compressive strength and wear resistance of epoxy resin. Increasing the number of heteroatoms in the FLG structure had little influence on the compressive strength of epoxy resin but improved its wear resistance.
This article introduces an innovative method for quantifying the degree of composition homogeneity in copolymers using mathematical modeling techniques. Applicable to copolymers for which the mechanism of microstructure formation can described in terms of the Markov chains, the method consists in obtaining a set of shares of unit sequences of a given length from a high-resolution NMR spectrum (set A) and then finding, through mathematical modeling of the Markov matrix, transient probabilities in order to build a model of a polymer chain containing such a set of shares of unit sequences (set B) that matches, as close as possible, set A. The dispersion resulting from the comparison of sets A and B is proposed as a quantitative criterion for the degree of composition homogeneity.
The process of benzoxazine resin curing in the presence of various catalysts was investigated. The catalytic activities were compared to identify the catalyst that most effectively reduced the benzoxazine curing temperature. The effect of the catalyst content on the curing of benzoxazine was assessed. The activation energies for the curing process were determined. The curing kinetics parameters were calculated from differential scanning calorimetry (DSC) data using Thermokinetics3 software. The possibility to control the temperature front and conversion of the binder through layer-by-layer changing of its composition (by varying the content of the catalyst in the benzoxazine system) across the thickness of the product, and thus altering the binder reactivity, was demonstrated. Based on the results obtained, a single-stage curing mode of benzoxazine binder that shortens the curing cycle through composite molding under dynamic heating conditions was singled out.
The temperature dependences of the diffusion, solubility, and permeability coefficients for ladder-like polyphenylsilsesquioxane (L-PPSQ) samples with molecular weights of 400, 600, and 1000 kDa were analyzed. A comparison, in terms of the gas transport parameters and temperature coefficients, with other silicon-containing polymers revealed that L-PPSQ is most similar to glassy polyvinyltrimethylsilane (PVTMS) rather than to polydimethylsiloxane (PDMS), which is structurally related to it. The heat of sorption values obtained for the studied samples using the temperature dependences are consistent with those from the literature for polytrimethylsilylpropyne (PTMSP), while their diffusion activation energies are more in agreement with PDMS and PVTMS, which may indicate the presence of enclosed free volume elements in L-PPSQ, comparable in size to the ones in PTMSP. The observed tendency of the permeability coefficient to increase with temperature confirms the dominant contribution of the diffusion component of permeability in L-PPSQ. The molecular weight of L-PPSQ was found to have no influence on its gas transport properties in the range of 400-1000 kDa. Therefore, the production of asymmetric and composite membranes is limited solely by the mechanical properties and solubility of L-PPSQ with different molecular weights.
