2026-02-26
ILNAR NURGALIEV et al.
A multiscale computational investigation integrating density functional theory (DFT) and molecular dynamics (MD) simulations was conducted to elucidate the mechanisms through which sulfur-containing donor molecules stabilize the photoactive α-phase of formamidinium lead iodide (FAPbI3) perovskites. The binding energetics, charge-transfer behavior, and hydrogen-bonding interactions of thiourea (TU), thiosemicarbazide (TSC), thiocyanate (SCN–), and diethyldithiocarbamate (DTC) were systematically analyzed. DFT results revealed pronounced Pb–S coordination and multidentate hydrogenbonding, with binding energies following the trend SCN–>TSC>DTC>TU. Thermodynamic analysis demonstrated that these additives lower the Gibbs free energy difference, thereby stabilizing the black α-phase, with TSC, TU, and to a lesser extent DTC exhibitingthe most pronounced effects. Projected density of statesanalysis confirmed that TU and DTC effectively suppressed trap states near the band edges without introducing midgap defects. MD simulations demonstrated preferential adsorption of all S-donors on FAPbI3 (001) surfaces, forming three to four hydrogen bonds per frame and achieving adsorption energies up to −52 kJ∙mol-1. These findings reveal a direct correlation between coordination strength, electronic coupling, and thermodynamic stabilization, establishing TU, TSC, and DTC as promising additives for improving the phase stability and electronic performance of FAPbI3-based perovskite solar cells.
2026-02-26
AYÇA İRGİT et al.
Abelson-1 (ABL-1) is a nonreceptor tyrosine kinase that plays essential roles in various cellular processes, including proliferation, survival, differentiation and its kinase activity is tightly regulated. The dysregulated ABL-1 kinase activity is linked to disease pathogenesis like Chronic Myeloid Leukemia (CML), where the BCR::ABL-1 fusion oncoprotein drives oncogenic signaling. Due to its central role in CML pathogenesis, understanding the structure of ABL-1 is crucial for the effective management of the disease and drug development studies. This study focuses on optimizing the expression, purification and crystallization of the recombinant human ABL-1 kinase domain for its structural analysis via X-ray crystallography and structure-based drug screening applications. The human ABL-1 kinase domain, fused with a SUMO-tag, was expressed in Escherichia coli Rosetta2 BL21 using the pET28(a)+ expression vector. The ABL-1 aggregates seen under native culture conditions were successfully solubilized by the mild ionic detergent sarkosyl. After obtaining soluble expression of the protein, Ni-NTA affinity chromatography was performed and high yield of purified ABL-1 was obtained. The 6X-His-SUMO-tag of purified ABL1 was cleaved by ULP1 protease. The recombinant ABL-1 was subsequently used in crystallization trials to enlighten structural features of ABL-1 that could guide the development of novel therapeutics and drug screening platforms targeting ABL-1 in CML.
2026-02-26
NALAN TÜRKÖZ KARAKULLUKÇU et al.
This study investigated the influence of synthetic sulfenimides on biodiesel–diesel fuel blends. Three previously synthesized sulfenimide derivatives were structurally characterized using spectroscopic techniques. We evaluated their antioxidant properties through phosphomolybdenum activity and reducing power capacity assays. The tested fuel samples were designated as D100, B10D90, B10D90_AA (ascorbic acid), B10D90_3, B10D90_2, and B10D90_1. The effect of adding 2000 ppm of the additive was measured using an Oxifast instrument following the ASTM D7545 standard, and the results were compared to those of the chemical antioxidant ascorbic acid. Inhibition time values were derived from the oxidation stability results. The starting temperatures for crystallization (Tc) of the mixtures were found using differential scanning calorimetry (DSC), and the measured temperatures were –7.24, –7.64, –7.89, –8.06, –8.39, and –8.52 °C. FT-IR spectra exhibited characteristic absorption bands associated with antioxidant functional groups, which means the sulfenimide compounds were successfully added. The addition of sulfenimides improved the oxidative stability of biodiesel blends. Furthermore, we conducted thermogravimetric analysis (TGA) at multiple heating rates to investigate the thermal decomposition kinetics of the sulfenimides. The activation energies for compounds 1, 2, and 3 were calculated using the Kissinger–Akahira–Sunose (KAS) method and were found to be 125.28, 111.34, and 88.11 kJ mol– ¹, respectively.
2026-02-26
SUSMITA SINGH et al.
Advancements in cost-effective and efficient alternative energy sources are critical for socioeconomic development. In this study, Iron-based metal–organic framework (Fe-MOF) electrocatalyst was fabricated using an Fe salt and ligand. Several surface characterization methods, including Fourier Transform-Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM), and X-ray diffraction (XRD), were used to characterize the electrocatalyst. Additionally, using Chronoamperometry (CA), Electrochemical Impedance Spectroscopy (EIS), Linear Sweep Voltammetry (LSV), and Cyclic Voltammetry (CV), the electrocatalytic behaviour in a cathodic reaction in PEMFCs is investigated. The study showed the material’s exceptional chemical or surface stability, and great surface morphology of the material that facilitated the cathodic reaction. This study reported the development of a Platinum Group Metal (PGM)-free potential electrocatalyst for oxygen reduction reaction at the cathode in Proton Exchange Membrane Fuel Cells (PEMFCs).
2026-02-26
MUSTAFA SOYLAK et al.
Determination of trace cobalt(II) (Co(II)) in real samples remains challenging because of its very low concentration and strong matrix interferences. In this study, a simple and green magnetic solid-phase extraction (mSPE) method was developed for the selective separation and preconcentration of Co(II) ions using a newly designed iron oxide/hexagonal boron nitride (IOhBN) nanocomposite. The material was synthesized through a one-step, surfactant-free coprecipitation process, combining the high surface area, stability, and layered structure of hBN with the magnetic and reactive features of Fe₃O₄ nanoparticles. This hybrid structure provided abundant active sites and rapid magnetic separability, enabling efficient extraction within 5 min using only 15 mg of sorbent. The optimized conditions were pH 7.0, eluent type and volume (3.0 mol L-¹ of HNO₃, 0.5 mL), and total extraction time of 5 min. The method exhibited reliable and environmentally efficient analytical performance with a limit of detection of 0.67 μg L-¹, a relative standard deviation of 4.2%, and an enrichment factor of 20. Validation with certified reference materials (water, BCR 505; onion NCS ZC 73033; spinach leaves, NIST1570a) and successful applications to water and food samples confirmed its reliability. The results demonstrate that the proposed IOhBN-based mSPE method is a novel, rapid, and environmentally sustainable approach for ultra-trace Co determination in complex matrices
2025-12-28
ZARİFE SİBEL ŞAHİN et al.
This study used single-crystal X-ray diffraction, elemental analysis, infrared (IR) spectroscopy, theoretical nuclear magnetic resonance (NMR), and theoretical ultraviolet spectroscopy to characterize 3 newly synthesized crystalline compounds. Additionally, the nonlinear optical, highest occupied molecular orbital energies, lowest occupied molecular orbital energies, band gap, molecular electrostatic potential, and thermodynamic parameters of the 3 crystalline compounds were examined. The strong correlation between experimental IR spectra and theoretical NMR chemical shifts confirmed the accuracy of computational predictions. The molecular formulas of the 3 newly synthesized crystalline compounds, each containing different ligand molecules, were: C8H14O4·2(C6H4N2), C5H7N2·NCS, and Ni(CN)4·2(C5H7N2)·2(H2O) for compounds 1, 2, and 3, respectively. Crystallographic analysis showed that the compounds crystallize in the space groups P1, P21/n and C2/m, respectively. Their molecular packing is stabilized by a network of hydrogen bonds (C–H∙∙∙O, O–H∙∙∙N, N–H∙∙∙N, N–H∙∙∙S, O–H∙∙∙N, and N–H∙∙∙O) and noncovalent interactions (C–H∙∙∙π and π∙∙∙π). Computational studies using Gaussian 03 and CrystalExplorer further elucidated their structural, magnetic, electrooptic, and electrochemical properties.
2025-12-28
VOLKAN DEMİREL et al.
This study investigates the extraction behavior of Y³⁺ ions using a Multi-Dropped Liquid Membrane (MDLM) system that employs di(2-ethylhexyl) phosphoric acid (D₂EHPA) as the carrier ligand. The focus is on the system’s ability to transport ions between aqueous phases selectively. The extracted complex was analyzed spectrophotometrically via ultraviolet–visible (UV–Vis) measurements after complexation with 0.05% Arsenazo III. The aim of this study was to determine the influence of the optimum D₂EHPA carrier concentration, together with the pH and temperature conditions of the donor and acceptor phases, on the system’s extraction performance. Accordingly, a series of extraction experiments was performed at different D₂EHPA concentrations, pH values, and temperatures to assess their combined effects on transport kinetics. The MDLM system achieved a maximum transport efficiency of 99.90% for Y³⁺ ions at a D₂EHPA concentration of 0.0045 mol/L, with a corresponding extraction time of 160 min. The shortest transport time of 120 min was observed at a carrier concentration of 0.0075 mol/L, confirming the strong influence of carrier concentration on extraction kinetics. The calculated low activation energy of 31.446 kJ/mol suggests that the transport of Y³⁺ ions through the MDLM system into the organic phase containing D₂EHPA is diffusion-controlled.
2025-12-28
AYSEL OKTAY et al.
In this work, electrochemical biosensors utilizing tyrosinase (Tyr) for the detection of the nonselective beta-adrenergic agonist isoproterenol (ISO) are presented. Three different configurations for immobilizing Tyr on a graphite electrode (GE) are compared: (1) GE modified with poly(diallyldimethylammonium chloride) (PDADMAC), PDADMAC/Tyr/GE; (2) PDADMAC combined with iridium nanoparticles (IrNPs) in a stepwise preparation, resulting in PDADMAC/IrNPs/Tyr/GE; and (3) a composite of PDADMAC and IrNPs mixed with Tyr at a 1:1 (v:v), forming PDADMAC/(IrNPs-Tyr)/GE. Surface morphology was characterized using scanning electron microscopy (SEM). Cyclic voltammetry (CV) and amperometry were applied to characterize the biosensor’s performance. Within the linear range of 5 μM to 211 μM, the biosensor PDADMAC/Tyr/GE exhibited a limit of detection (LOD) of 1.4 μM and a limit of quantification (LOQ) of 4.1 μM. PDADMAC/IrNPs/Tyr/GE displayed improved sensitivity with an LOD of 0.9 μM and an LOQ of 2.8 μM. The configuration PDADMAC/(IrNPs-Tyr)/GE demonstrated the best performance with an LOD of 0.3 μM and an LOQ of 0.8 μM. The slopes (0.0147 μA/M, 0.0096 μA/M, and 0.0031 μA/M for PDADMAC/(IrNPs-Tyr)/GE, PDADMAC/IrNPs/Tyr/GE, and PDADMAC/Tyr/GE, respectively) of the concentration dependencies for the three sensor modifications (which represent the analytical sensitivity) demonstrate the achieved enhancement of analytical performance by IrNPs. Furthermore, the biosensor’s ability to detect ISO in the presence of potential interferences, such as ascorbic acid, uric acid, and paracetamol, was assessed. Additionally, we demonstrated the biosensor’s potential to detect ISO in diluted spiked human serum samples.
2025-12-28
HALUK ÇETİNOK et al.
Human serum albumin (HSA) is a ubiquitous, multifunctional protein responsible for the systemic distribution of both endogenous metabolites and exogenous pharmaceuticals. Its inherent properties, particularly its ability to seep into tissues and its multiple ligand-binding sites, have rendered HSA an attractive vehicle for nanoparticle-based drug delivery systems, particularly for cancer targeting. In this study, we present high-resolution crystallographic data revealing two distinct dimerization patterns of HSA (Protein Data Bank [PDB] ID: 9V61) obtained under high-concentration crystallization conditions, along with results from dipyridamole docking. Both dimer types demonstrate extensive interface areas and a significant number of electrostatic interactions. Comparative analysis with a previously reported dimer structure (PDB ID: 3JQZ) and other high-interface-area structures (PDB ID: 5Z0B, PDB ID: 8CKS) indicates similarities in contact regions but unique residue-level differences in bonding interactions. Interface surface area distribution and space group histograms further support the rarity and potential physiological relevance of the identified dimer forms. Importantly, these dimer configurations do not disrupt Sudlow’s drug-binding sites, as the dipyridamole docking analysis shows strong affinity for sites I and III without affecting their utility in engineered drug delivery. Our findings open new avenues for structure-based mutagenesis and nanoparticle design strategies centered on HSA dimerization dynamics.