2025-12-27
M.M. Burkitbayev, U.Zh. Dzhusipbekov, G.O. Nurgalieva, Z.K. Bayakhmetova, D. Duisenbai, Sh.N. Nazarkulova, I.V. Matveyeva, Ye.Yu. Yarovaya
Humic substances (HS) possess significant physiological activity and play a crucial role in enhancing soil properties and plant productivity. This study is devoted to the determination of the content of natural radionuclides in humate-containing samples obtained from natural raw materials of Kazakhstan. Five samples, including both solid and liquid fertilizers, were prepared and analyzed. Key parameters such as elemental composition, content of carboxyl and phenolic groups, and the yield of free humic acids were determined. The concentrations of uranium-238, uranium-234, thorium-232, thorium-230, thorium-228, polonium-210, and lead-210 isotopes were measured using alpha-spectrometric and alpha-beta radiometric methods. Results indicated that the liquid fertilizer exhibited the lowest radionuclide activities, while the solid samples showed varying levels of radioactive isotopes, with the highest activity recorded in sample A2. Nonetheless, the specific activities of all measured radionuclides complied with the national radiation safety standards (SanPiN 2.6.1.2523-09), confirming the fertilizers' safety for agricultural use. This work highlights the importance of radiation monitoring in fertilizers and the potential of humate-containing materials as environmentally friendly agricultural enhancers. The findings contribute to the development of sustainable agricultural practices through the safe utilization of natural organomineral fertilizers derived from local raw materials. Keywords: Humic substances, natural radionuclide, fertilizers, uranium series, activity concentration
2025-12-27
T.V. Polyudova, T.A. Akentieva, M.V. Antipeva, A.L. Esaev, L.P. Yunnikova
This study investigated the biological activity of tropylated aniline 4-(7-cyclohepta-1,3,5-trienyl)aniline and its derivatives belonging to the group of secondary aromatic amines – N -2-hydroxyphenylmethyl-4 1 -(7-cyclohepta-1,3,5-trienyl)aniline and the group of azomethines – N -2-hydroxyphenylmethylene-4 1 -(7-cyclohepta-1,3,5-trienyl)aniline. Tropylated aniline was synthesized by mixing tropyllium tetrafluoroborate and aniline in ethanol. N -2-hydroxyphenylmethyl-4 1 -(7-cyclohepta-1,3,5-trienyl)aniline and N -2-hydroxyphenylmethylene-4 1 -(7-cyclohepta-1,3,5-trienyl)aniline were obtained via a one-pot multicomponent synthesis. Tropylated aniline and its derivatives showed no toxic effects on Galleria mellonella larvae upon invasive administration of 10 µL solutions at a concentration of 1 mg/mL (10 µg/larva). In vitro experiments demonstrated that Gram-negative bacteria and Gram-positive bacteria with hydrophilic cell walls exhibit low susceptibility to tropylated aniline and are resistant to its derivatives. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the studied compounds were determined. The MBC/MIC ratio for all susceptible bacteria was ≤4, indicating their bactericidal activity. A dependence of bacterial susceptibility to tropylated aniline and its derivatives on the level of bacterial cell hydrophobicity was demonstrated. High susceptibility to the studied compounds was revealed in mycomembrane bacteria of the Mycobacterium genus, whose cell walls contain mycolic acids and exhibit a high level of hydrophobicity. The obtained compounds are of practical relevance as potential anti-tuberculosis agents. Key words: antibacterial activity, hydrophobicity, tropylidene cycle, mycomembrane, toxicity, Galleria mellonella
2025-12-27
N. Popov, V. Barabanov, S. Shalgimbayeva, D. Batayeva, A. Zhumanova, A. Muratkyzy, B. Abdullayeva
The article presents information on hydrobiological monitoring in the Ural–Caspian Basin, including phytoplankton, zooplankton, and benthic communities in the Ural–Caspian Basin. The annual dynamics of hydrobiont biomass density have been established, showing seasonal variations with the highest values in summer and the lowest in winter. The qualitative and quantitative composition of aquatic organisms was studied depending on the discharge volume and flow levels of the Ural (Zhaiyk) River. In high-water years, the biomass of phytoplankton and the abundance of zooplankton increased by 1.4 and 2.2 times, respectively. In recent years, an increase in the biomass of gelatinous zooplankton has been observed. Among them, the comb jelly Mnemiopsis is spreading particularly actively, successfully colonizing shallow, low-salinity areas of the sea. This species is a major consumer of zooplankton, which negatively affects the food base of planktivorous fish and the juveniles of all ichthyofauna species in the Caspian Sea. An analysis was also conducted on the feeding preferences of anadromous, marine, semi-anadromous, and freshwater species inhabiting the Caspian Sea. Keywords: forage base, abundance, biomass, ichthyofauna, fish diet.
2025-12-27
F.A. Amirli, R.F. Khankishiyeva, A.F. Mammadova, S.T. Bayramova, G.G. Azizova, K.B. Iravanlı
In this study, binary blends based on ethylene–propylene–diene rubber (EPDM) and polyamide-6 (PA6) were systematically prepared with varying PA6 contents ranging from 10 to 40 phr. Dicumyl peroxide (DCP) was employed as a reactive compatibilizer in order to promote chemical linkages between the elastomeric and thermoplastic components and thereby enhance interfacial adhesion. The blending process was carried out in a Banbury internal mixer under controlled temperature and shear conditions, ensuring homogeneous distribution of the polyamide phase within the EPDM matrix, and the obtained compounds were subsequently compression molded to produce uniform test specimens. The effect of increasing PA6 concentration on the physicomechanical, thermal, and morphological characteristics of the blends was extensively investigated. Tensile testing demonstrated that the incorporation of higher amounts of PA6 significantly increased tensile strength, modulus, and Shore hardness, which can be attributed to the reinforcing action of the rigid polyamide domains and the formation of peroxide-induced covalent interfacial linkages. Thermal gravimetric analysis further revealed an improvement in thermal stability with rising PA6 content, while differential scanning calorimetry and dynamic mechanical analysis indicated a gradual upward shift in storage modulus and in the glass transition behavior, consistent with the contribution of the stiff thermoplastic phase. On the other hand, elongation at break and overall elasticity decreased as the PA6 fraction was raised, reflecting the stiffer and less deformable nature of the dispersed polyamide particles. Scanning electron microscopy (SEM) images confirmed that optimal phase dispersion and strong interfacial adhesion were obtained in blends containing approximately 20–30 phr PA6 together with 1.0–1.2 phr DCP. These particular formulations offered the best balance between mechanical strength, flexibility, and heat resistance. Overall, the results demonstrate that peroxide-compatibilized EPDM/PA6 blends possess tunable and application-oriented properties suitable for engineering uses where both mechanical robustness and thermal durability are simultaneously required. Keywords: EPDM, PA6, reactive compatibilization, dicumyl peroxide, mechanical properties, thermal stability, morphology.
2025-12-27
G. Bayandy, N. Baltakhozha, K. Yerkinova, K. Nurpeis, G. Sailauova, I. Smekenov, A. Bissenbaev
Rabies remains a serious global public health concern. The envelope glycoprotein of the rabies virus (RABV-G) is the principal viral antigen and harbors critical neutralizing epitopes, making it a promising target for subunit vaccine development and diagnostic applications. Nevertheless, the efficient production of recombinant RABV-G with preserved antigenic and immunogenic properties remains technically demanding. In this work, we developed an optimized strategy for the expression and purification of recombinant RABV-G and assessed its antigenicity and immunogenicity. The rabies virus glycoprotein ectodomain (rRABV-GE) was successfully expressed in Escherichia coli Rosetta2(DE3)pLysS and purified in a biologically relevant form. The rRABV-GE gene was codon-optimized and cloned into the pET-28c(+) expression vector, resulting in recombinant protein expression largely in an insoluble state. Consequently, the protein was subjected to refolding and purification procedures. To improve protein solubility, hydrophobic loop regions were substituted with flexible linker sequences. Protein purification was performed under denaturing conditions using urea, followed by affinity chromatography. The identity and antigenicity of the purified protein were confirmed by Western blot analysis and indirect enzyme-linked immunosorbent assay (ELISA). ELISA testing was performed using rabbit sera collected from animals immunized with the commercial Purified Vero Cell Rabies Vaccine (RHABDOVAC-1). Collectively, these findings indicate that the optimized bacterial expression platform enables the production of biologically relevant rRABV-GE and provides a cost-effective approach for the development of rabies subunit vaccines and diagnostic reagents. In summary, the recombinant rRABV-G protein produced in this study appears to be a suitable diagnostic antigen for ELISA-based and other rabies virus immunodiagnostic uses. Keywords: Rabies virus, glycoprotein ectodomain, antibody, ELISA, Rosetta2(DE3)pLysS, vaccine.
2025-12-27
N. Zhumasheva, E. Nurgaziyeva
Over the past ten years, lithium-ion batteries (LIBs) have become indispensable for powering wearable technology, smart electronics, and electric cars. However, the use of extremely flammable and volatile liquid electrolytes in typical Li-ion rechargeable batteries raises serious safety issues and prevents future advancements in energy density and dependability. Solid electrolytes have been suggested as viable solutions to these problems. In particular, polymer-based solid electrolytes combine high ionic conductivity with advantages such as low flammability, mechanical flexibility, thermal stability, and improved safety. This review highlights recent advances in solid polymer electrolytes for LIBs, with a focus on their fabrication strategies, structural designs, ionic conductivities, and electrochemical/mechanical stabilities. Keywords: Lithium-ion batteries, Solid polymer electrolytes, Ionic conductivity, Safety, Electrochemical stability, Fabrication strategies.
2025-12-27
T. Maryyam, S. Rahayu, D. Sukmawati, A.H. Anvar, H.A. Shakir, M. Khan, J. Ul-Haq, M. Irfan
Cellulase refers to a group of enzymes that can break down cellulose, the most widespread organic polymer on Earth. It is one of the most important industrial enzymes due to its application in the production of valuable products such as biofuels, papers and textiles. Many microorganisms naturally produce cellulase, including Bacillus species. This study presents detailed bibliometric analysis of Bacillus cellulase. The core objective of this study is to provide global research trends related to Bacillus cellulase. It highlights leading authors, institutions, countries and sources that have major contributions in this area of research. The Scopus Dataset of 2212 documents was included for analysis. VOSviewer and Biblioshiny software were employed for bibliometric analysis and visualization. The most prolific author was Zhang Y with highest number of publications (45) and citations. China ranked first among top contributing countries, followed by India with second position. This study will help researchers in understanding global research trends on Bacillus cellulase. Keywords: Bacillus , cellulase, Bibliometric study, VOSviewer, Biblioshiny.
2025-12-27
S. Bayazit
The present study focuses on the molecular docking and interaction analysis of the Kazcaine (1-(2-ethoxyethyl)-4-ethynyl-4-benzoyloxypiperidine) derivative KazMeI with the α-glucosidase enzyme (PDB ID: 5NN4), the principal therapeutic target in the treatment of type 2 diabetes mellitus. For crystal structure modeling of human lysosomal acid-alpha-glucosidase, GAA/N-acetyl-cysteine complex was utilized. The ligand structure was designed in ChemDraw, geometry-optimized using a Python-based MM2 molecular mechanics force field, and converted to PDBQT format in AutoDockTools v1.5.6. The protein structure was prepared by removing water molecules, adding polar hydrogens, and centering the docking grid at coordinates (–6.152, –33.636, 91.204 Å). Docking simulations performed in AutoDock4.2 using the Lamarckian Genetic Algorithm produced ten conformations with highly consistent binding orientations. The lowest binding free energy (ΔG) was –7.00 kcal/mol, corresponding to an inhibition constant (Ki) of 7.37 μM, indicating moderate yet biologically relevant affinity. Interaction analysis revealed that KazMeI forms hydrophobic and π–π stacking contacts with Leu286, Pro285, Leu291, and Trp613, and hydrogen bonding with Ser601 and Thr286, while the quaternary ammonium group interacts electrostatically with Arg600. These results confirm the predicted antidiabetic potential of the patented derivative KazMeI compound (Utility Model Patent No. 9796, Kazakhstan, 2024) and support its further development as a lead α-glucosidase inhibitor. Keywords: Autodock, Pymol, ChemDraw, molecular docking, α-glucosidase, Kazcaine derivative, antidiabetic agents