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Identification of a Novel miR-122-5p/CDC25A Axis and Potential Therapeutic Targets for Chronic Myeloid Leukemia
No full textChronic myeloid leukemia (CML) is a myeloproliferative neoplasm characterized by uncontrolled proliferation of myeloid cells. MicroRNAs (miRNAs), small noncoding RNAs, regulate post-transcriptional gene expression by degrading target mRNAs or repressing translation. Dysregulated miRNA expression has been implicated in various malignancies, including CML, where they can function as oncogenes or tumor suppressors. This study aimed to investigate the relationship between miR-122-5p and cell division cycle 25A (CDC25A) in CML and to elucidate the regulatory mechanisms of miR-122-5p. This study integrates bioinformatics analysis with in vitro RT-qPCR validation in K562 chronic myeloid leukemia cells to explore the potential regulatory relationship between miR-122-5p and CDC25A. mRNA expression profiles were retrieved from the GSE100026 dataset in the Gene Expression Omnibus (GEO), and differentially expressed genes were identified using GEO2R. Quantitative real-time PCR (RT-qPCR) was performed to measure miR-122-5p, CDC25A, and cyclin-dependent kinase 4 (CDK4) expression levels. Bioinformatics analyses (miRNeT, miRDIP, TargetScan, BioGPS, GeneMANIA, STRING) were applied to predict molecular interactions and functional pathways. Public RNA-seq datasets and in silico tools were used to prioritize candidates; RT-qPCR in a single CML cell line (K562) provided in vitro expression validation. In K562 cells, miR-122-5p expression was significantly reduced, while CDC25A and CDK4 were markedly upregulated. Bioinformatics tools confirmed CDC25A as a potential miR-122-5p target. Functional enrichment indicated CDC25A involvement in cell cycle regulation and apoptosis. These findings suggest that miR-122-5p functions as a tumor suppressor in CML by targeting CDC25A. Modulating the miR-122-5p/CDC25A axis may provide potential molecular targets for inhibiting CML progression through regulation of cell cycle pathways. Findings are exploratory and based on bioinformatics with limited in vitro expression confirmation; functional studies are required to establish causality
Antimicrobial activity of composite materials from the calcium-phosphate group with chitosan
No full textIn this study, the antimicrobial activity of calcium phosphate-based materials was investigated. The materials that were used were hydroxyapatite (HAp), strontium-doped hydroxyapatite (SrHAp), and octacalcium phosphate (OCP). All samples were synthesized by wet-chemical precipitation, and their characterization was performed using FTIR, SEM, and X-ray diffraction (XRD). In addition, composites of all samples were prepared using commercial low-molecular-weight chitosan (50–190 kDa) with a high degree of deacetylation (75–85%). This work aimed to determine the antimicrobial activity of the individual materials and identify which calcium phosphate materials, in combination with chitosan, exhibit the best antimicrobial activity. Antimicrobial tests were conducted against Salmonella Enteritidis and Candida albicans. The results showed that pure hydroxyapatite exhibited the most potent antimicrobial activity against S. Enteritidis, whereas strontium doping reduced this activity. In contrast, the best activity against C. albicans was observed for OCP, whereas the combination of SrHAp and chitosan showed the weakest effect. The results indicate that chemical modification of hydroxyapatite significantly affects its antimicrobial activity, and that combining it with chitosan can yield composites with excellent antimicrobial properties, making them potential candidates for the development of various biomaterials.Twenty-Third Young Researchers' Conference Materials Science and Engineering, December 3-5, 2025, Belgrade, Serbia
Investigating structural and optical properties of Eu3+-doped MgGd2Zr2O8 for application in optical thermometry
No full textThis study presents the synthesis and characterization of a novel luminescent material, MgGd2Zr2O8 doped with (2, 5, 10, 15, 20, and 25 at%) Eu3+ ions, and explores its potential application in optical thermometry. The samples were synthesized via a simple sol–gel route and subsequently thermally treated for 4 hours at 850 °C. X-ray powder diffraction (XRPD) analysis combined with Rietveld refinement revealed that the obtained samples crystallize in a fluorite-type cubic structure (space group Fm3̅m), exhibiting crystallite sizes of approximately 7 nm and a lattice parameter expansion attributed to Mg²⁺ ions preferentially occupying interstitial or vacant sites. Transmission electron microscopy (TEM) revealed that the material consists of irregularly shaped aggregates formed by the clustering of smaller particles (<100 nm). High-resolution TEM images confirmed the crystalline nature of the sample, with lattice planes consistent with XRPD results and crystallite sizes below 10 nm. Elemental mapping obtained through energy-dispersive spectroscopy (EDS) showed a homogeneous spatial distribution of all constituent elements. Photoluminescence (PL) spectra displayed characteristic Eu³⁺ emission transitions from the ⁵D₀ excited state to the 7FJ (J = 1– 4) levels. The optimal dopant concentration was determined to be 15 at%, beyond which concentration quenching occurred. Temperature-dependent luminescence measurements were performed in the 300–550 K range using the luminescence intensity ratio (LIR) method, based on non-thermally coupled transitions ⁵D₀ → ⁷F₁ and ⁵D₀ → ⁷F₂. The maximum relative sensitivity of 0.3 % K⁻¹ at 550 K was achieved for the LIR592/612 ratio, while the LIR586/612 ratio showed a more moderate, yet stable sensitivity of approximately 0.1 % K⁻¹ at temperatures above 430 K.Twenty-Third Young Researchers' Conference Materials Science and Engineering, December 3-5, 2025, Belgrade, Serbia
Microwave-assisted synthesis of carbon quantum dots for adsorption applications
No full textThe increasing discharge of industrial effluents containing toxic organic dyes (Methylene Blue, Rhodamine B, Rose Bengal, etc.) has become a major environmental concern due to their persistence, stability, and harmful effects on aquatic ecosystems. Developing efficient, low-cost, and sustainable materials for dye removal is therefore of significant importance. Carbon Quantum Dots (CQDs) have attracted attention as a promising class of nanomaterials because of their high surface area, water solubility, tunable photoluminescence, and simple, eco-friendly synthesis routes. In this work, pristine CQDs were synthesised from simple carbon-based precursors (glucose) using a microwave-assisted method which provides rapid and uniform heating of the reaction mixture, enabling homogeneous formation of carbon nanoparticles within minutes. This green, one-step, low-cost, and energy-efficient approach significantly shortens the reaction time, reduces energy consumption, minimizes the formation of by product, and ensures high reproducibility. The resulting quasi-spherical CQDs exhibited uniform particle size distribution and abudant functional groups such as hydroxyl and carboxyl groups, enhancing their surface reactivity. The obtained CQDs exibited significant adsorption performance toward Methylene Blue, achieving 50% removal immediately upon mixing. This rapid and efficient dye adsorption can be attributed to multiple interaction mechanisms, including π-π stacking between aromatic rings, electrostatic attraction between charged sites, and hydrogen bonding with functional groupes on the CQD surface. These findings demonstrate the high potential of pristine CQDs as effective, sustainable, and scalable adsorbents for wastewater treatment applications.Twenty-Third Young Researchers' Conference Materials Science and Engineering, December 3-5, 2025, Belgrade, Serbia
Edge modes in strongly nonlinear saturable SSH photonic lattices: Tracing a bulk-edge correspondence through instabilities and bifurcations
No full textPhotonic lattices with a saturable nonlinear response generally exhibit a second linear regime at high light intensities. Here, we perform a detailed numerical analysis of nonlinear continuations of the topological edge mode of a Su–Schrieffer–Heeger (SSH) chain, following the family of exact nonlinear stationary solutions through instabilities and bifurcations from the low-intensity to the high-intensity linear limit. The properties of the nonlinear edge modes define several regimes corresponding to qualitatively different dynamics for edge excitations. For each of these nonlinear regimes we numerically calculate the evolution of two commonly used indicators of nontrivial bulk topology: the mean field displacement and the Zak phase obtained from projector matrices. Thus, we determine the extent to which one may establish an approximate bulk-edge correspondence, characterized by dynamically stable nonlinear edge modes and well defined approximate Zak phases, in the full nonlinear regime of the saturable lattice. © 2025 The Author
Унапређење пригушних елемената конфузора у циљу повећања хомогености поља брзина димног гаса у попречним пресецима комора ЕФ котла К6 блок А5 ТЕ Колубара
No full textTransportni procesi čvrstih čestica pepela u otpadnom gasu postrojenja za sagorevanje mogu biti prirodni (usled dejstva gravitacione sile) i veštački (usled dejstva centrifugalne i elektrostatičke sile).Broj: TR 16/202
Spin-Lattice Coupling and Multiferroic Modulation in Ho-Doped BiFeO₃: An Experimental and Theoretical Study
No full textBismuth ferrite (BiFeO₃, BFO) is one of the most intensively studied multiferroic materials due to its simultaneous ferroelectric and antiferromagnetic behaviour at room temperature, making it highly promising for a wide range of technological applications, including spintronics, memory devices, and sensor technologies [1-3]. Despite significant research interest, controlled tuning of its electronic and magnetic properties through rare-earth doping remains a fundamental and practical challenge. We systematically investigated the effects of Ho doping on the structural, electronic, and magnetic properties of BFO using a combined experimental and theoretical approach. Nanopowders with the composition Bi₁₋ₓHoₓFeO₃ (x = 0.02, 0.05, and 0.10) were synthesized by hydrothermal synthesis, and their crystal structure was thoroughly analyzed using X-ray diffraction (XRD), revealing phase stability with gradual structural transformations dependent on dopant concentration. Furthermore, bond valence calculations (BVC) identified six energetically favourable structural modifications of the Ho-doped system: a-, b-, g-, R-, T₁-, and T₂-phases. These structural configurations were further examined using advanced computational simulations based on density functional theory (DFT) to evaluate the stability of different magnetic orderings, electronic structures, and the evolution of ferroelectric properties with increasing Ho concentration. The results of our theoretical and experimental investigations reveal a rich spectrum of electronic and magnetic phenomena in Ho-doped BFO, offering new insights into the control of multiferroicity through doping. These findings have significant implications for further research and the development of advanced multiferroic materials with enhanced functional properties, suitable for innovative nanoelectronics and spintronic applications.Advances in Solid State Physics and New Materials - 30 years of the Center for Solid State Physics and New Materials at the Institute of Physics Belgrade, 19 – 23 May 2025, Belgrade, Serbia
A Comparative Study of A2SiF6 (A = Cs, K) Phosphor Host Matrices: Linear Combination of Atomic Orbital Hybrid Density Functional Theory Calculations
No full textCesium hexafluorosilicate (Cs2SiF6, CSF) and potassium hexafluorosilicate (K2SiF6, KSF) compounds are suitable hosts for luminescent impurities. In this work, the results of first-principle calculations of the basic properties of both these compounds are discussed and compared with the available experimental and theoretical data. The simulations were performed using the CRYSTAL23 computer code within the linear combination of atomic orbitals (LCAO) method of the density functional theory (DFT) and the advanced hybrid DFT-HF exchange-correlation B1WC functional. A comparative study of the structural, electronic, and elastic properties of the two materials is presented, along with a study of the dependence of properties on external pressure in the range of 0–20 GPa. In particular, the electronic properties with an emphasis on the effective atomic charges (by means of Mulliken analysis) and the chemical bonding properties (by means of crystal orbital overlap population (COOP) analysis) were addressed, with regards to the pressure effects. The structure of the valence bands at 0 and 20 GPa was compared. The vibrational properties of CSF and KSF were calculated, including the simulation of the one-phonon IR and Raman spectra. The calculated Raman spectra exhibit excellent agreement with the experimental ones. The pressure dependences of sound speeds and the Debye temperature are evaluated
Electrochemical oxidation of bisphenol S with SnO₂-MWCNT electrodes
No full textRhodamine B is a synthetic dye commonly used in the textile and printing industries, recognized as a significant water pollutant. It enters aquatic environments primarily through untreated wastewater, posing serious threats to both environmental ecosystems and human health due to its toxic, carcinogenic, and non-biodegradable properties. The dye's persistence in water can result in harmful effects on ecosystems and contamination of vital water sources, underscoring the urgent need for effective removal methods. Electrochemical degradation has emerged as an eco-friendly technology to tackle this issue, breaking down Rhodamine B into less harmful byproducts and providing a sustainable approach for mitigating its environmental impacts. This study investigates the electrochemical degradation of Rhodamine B using glassy carbon (GC), stainless steel (SS), and nickel (Ni) electrodes in an undivided two-electrode system operating under a galvanostatic regime at a current density of 15 mA cm⁻². The primary goal was to compare the efficiency and kinetics of degradation across different electrode types. Experimental results demonstrated that GC electrodes, followed by SS, exhibited the highest degradation efficiency, with the process adhering to first-order kinetics. These findings highlight the advantages of GC electrodes in terms of speed and efficiency, offering valuable insights for optimizing treatment processes.Proceedings / XVI International Mineral Processing and Recycling Conference, IMPRC, 28 – 30 May 2025, Belgrade, Serbia
Activated Carbons from Apricot Kernel Shells for Wastewater Treatment: Adsorption of Pb2+ and Rhodamine B with Equilibrium, Kinetics, Thermodynamics, and DFT Analysis
No full textApricot kernel shells were evaluated as a sustainable activated carbon precursor for wastewater treatment using experimental and theoretical methods. Two adsorbents were synthesized: physically activated with CO2 (AKS-CO2) and chemically activated with H3PO4 (AKS-H3PO4). Comprehensive materials characterization and adsorption tests using Pb2+ ions and Rhodamine B dye (RhB) as model pollutants revealed that AKS-H3PO4 significantly outperformed its physically activated counterpart. With an exceptionally high specific surface area (1159.4 m2/g) enriched with phosphorus-containing functional groups, the chemically activated carbon demonstrated outstanding removal efficiencies of 85.1% for Pb2+ and 80.3% for RhB. Kinetic studies showed Pb2+ adsorption followed pseudo-second-order kinetics, indicating chemisorption, while RhB adsorption fitted pseudo-first-order kinetics, suggesting intra-particle diffusion control. The thermodynamic analysis confirmed the spontaneity of both processes: Pb2+ adsorption was exothermic under standard conditions with positive isosteric heat at higher concentrations, reinforcing its chemisorption nature, whereas RhB adsorption was endothermic, consistent with physisorption. Density Functional Theory (DFT) calculations further elucidated the mechanisms, revealing that Pb2+ preferentially binds to oxygen-containing functional groups, while RhB interacts through hydrogen bonding and π–π stacking. These findings establish chemically activated apricot kernel shell carbon as a high-performance adsorbent, exhibiting exceptional removal capacity for both ionic and molecular contaminants through distinct adsorption mechanism