ChemistrySelect最新文献

Dy³⁺-activated sodium strontium zinc borate (NSZB:Dy) glasses with composition 20 Na₂O  −  10 SrO  −  9 ZnO  −  (61 − x) B₂O₃ −  x Dy₂O₃ (where x = 0, 0.2, 0.4, 0.6, 0.8, and 1.0 mol%) have been synthesized to explore their physical, structural, and optical attributes. These glasses were prepared using the conventional melt–quenching technique and were characterized through X-ray diffraction (XRD), Fourier transform infrared (FTIR), and UV–visible spectroscopic techniques. Density measurements have been performed using Archimedes principle, and thorough analysis of other physical parameters namely average molecular weight, molar volume, polaron radius, ion concentration, inter-nuclear distance, and optical basicity have also been conducted. X-ray diffraction confirmed the amorphous nature of glasses while FTIR analysis highlighted the presence of various structural groups present in prepared amorphous media. Optical absorption spectra, with wavelengths ranging from 280 to 850 nm, displayed absorption peaks/bands originating from ground state of Dy³⁺. The indirect optical band gap of the glasses was determined using Tauc's plot and was observed to decrease with increasing Dy₂O₃ concentration. The band gap values were used to calculate other optical parameters and were seen to vary with Dy₂O₃ content.

This work presents a novel computational pipeline for designing benzofuran-derived mTOR inhibitors, combining advanced machine learning techniques with molecular modeling approaches. Using a carefully selected set of 52 benzofuran analogs, we established a highly predictive 3D-QSAR model (R² = 0.94, Q² = 0.78) that identified crucial molecular features influencing inhibitory activity. Through systematic virtual screening, compound A7 emerged as the most promising candidate, exhibiting exceptional binding energy (-8.49 kcal/mol) to the mTOR catalytic domain through specific interactions with Val2240 (1.86 Å hydrogen bond) and Tyr2225 (π-stacking). Quantum mechanical analyses uncovered distinctive electronic properties of A7, including a small HOMO-LUMO energy separation (2.0 eV) and favorable charge distribution patterns. Comprehensive pharmacokinetic evaluation revealed optimal drug-like characteristics for A7, with excellent predicted oral bioavailability (96% absorption) and minimal toxicity concerns. Our integrated computational strategy demonstrates the potential of benzofuran derivatives as mTOR-targeted therapeutics while providing a validated protocol for structure-based drug discovery.

The present study was carried out in order to determine the chemical composition of essential oil from Lantana camara (Verbenaceae) collected from El Hamma (Southwest of Setif –Algeria) and to evaluate its insecticidal potential against Culiseta longiareolata (Diptera, Culicidae). The aerial part was hydrodistilled in a Clevenger type apparatus and analyzed by gas chromatography–mass spectrometry. The larvicidal activity against the fourth instar larvae was determined after 24, 48, and 72 h of exposure according to the World Health Organization procedure. The effect of lethal concentration (LC50) was examined on metabolites quantities (carbohydrates, lipids, proteins) at different exposure periods. GC–MS analysis of the L. camara essential oil revealed 71 compounds representing to 99% of the total oil, in 0.10% yield, which the major compounds were caryophyllene (25.16%). The toxicity results showed a highly larvicidal activity with a dose–response relationship, where the LC10, LC25, LC50, and LC90 values at 24 h of exposure were 1.41, 2.87, 6.29, and 27.98 ppm, respectively. The treatment by LC50 induced and a significant impact on the energy reserves, especially on carbohydrates and lipids. Our findings showed that this essential oil has the potential to be used as a mosquito control alternative to chemical insecticides.

Zinc oxide (ZnO) and bismuth tungstate (Bi₂WO₆) are promising semiconductor materials for photocatalytic applications due to their unique optical and electronic properties. However, rapid electron-hole recombination limits their efficiency. This research used solvothermal and hydrothermal methods to prepare Bi₂WO₆-ZnO/graphene oxide (GO) nanocomposites. Characterization confirmed successful heterostructures, with GO improving surface area, charge separation, and visible-light absorption. Under visible light, the Bi₂WO₆-ZnO/GO (3 wt%) photocatalyst removed 87.9% of methylene blue (20 mg L⁻¹, pH 6.07) in 180 min. The composite displayed good reusability, maintaining a degradation efficiency above 69.7% after five cycles. This enhanced performance is attributed to GO's role in reducing electron-hole recombination and providing a large surface area. Scavenger experiments identified hydroxyl radicals (•OH) as the primary reactive species driving MB degradation. The nanocomposites also exhibited strong antimicrobial activity against Escherichia coli under visible light. Notably, GO incorporation resulted in a sixfold enhancement in photocatalytic activity. The reaction rate constant (k) increased significantly from 0.0015 min⁻¹ for the Bi₂WO₆-ZnO (0.3:1) composite to 0.0089 min⁻¹ for the Bi₂WO₆-ZnO (0.3:1)/3GO system. These findings underscore the potential of Bi₂WO₆-ZnO/GO composites for environmental applications, including pollutant degradation and water disinfection, offering a scalable solution for addressing water contamination challenges.

The rise of effective systems of electrochemical energy storage is today a research hotspot in the conditions of transformation of the global energy structure and the large-scale integration of new energy. Solving the problem of poor conductivity and structural stability in current electrode materials, graphene aerogels have appeared as the best materials to solve the existing technological bottlenecks since they bear considerably good electrical conductivity, extremely large specific surface area, and stable structure. The current paper takes a systematic review of the research advances in the study of graphene aerogels and outlines the preparation methods, including in situ assembly, chemical cross-linking, the template method, 3D printing technology, and the sustainable synthesis method of biomass, in which such preparation methodologies can affect material microstructure. It is on this foundation that this research study examines the action mechanisms and applications of these materials in supercapacitors, zinc-air batteries, and lithium-ion batteries. It offers a deep examination of ways of performance optimization through building composite structures that consist of carbonaceous materials, covalent organic frameworks, and metal compounds. Finally, technical challenges are summarized and future trends forecasted to guide the design of novel, efficient energy storage devices.

We propose a variational quantum regression (VQR) algorithm using a hardware-efficient ansatz (HEA) structure. This approach enables the quantum state to directly encode classical tabular data with variational parameters corresponding to real-valued regression coefficients, ensuring high interpretability and efficient optimization without sacrificing expressiveness. By combining a variational quantum circuit with a classical optimizer, our method predicts the ground-state energy of a hydrogen molecule using full configuration interaction (FCI) data. We quantify the expressibility of the VQR HEA circuit via the Kullback–Leibler (KL) divergence D_KL and show the advantages of our R_y − R_x gate sequence in balancing expressibility. Performed for pennylane using an idealized quantum simulator, our 4-qubit, 5-layer HEA-based VQR model achieves an accuracy of ∼0.99, mean squared error (MSE) < 10⁻⁶ Hartree², and mean absolute error (MAE) around 0.1 × 10⁻² Hartree compared to FCI benchmarks. We further demonstrate how qubit number and layer depth influence model accuracy, providing insights for task-specific quantum circuit design. Our results advance practical applications of quantum computing for electronic structure problems by introducing an expressive, interpretable ansatz tailored for high-precision simulations.

Four pyrazole-based ligands (L1–L4) were synthesized in a one-step procedure and evaluated as corrosion inhibitors for mild steel in 1 M HCl and artificial seawater (ASW). In 1 M HCl, electrochemical impedance spectroscopy (EIS) shows that ligand L1 exhibits the highest inhibition efficiency, 94.92% at 300 ppm, whereas L2 and L3 afford only moderate protection, and L4 is the least effective. In ASW, the halogenated ligand L2 displays the best performance, 73% inhibition after five days of immersion; under these conditions, L1 acts as a moderate inhibitor, while L3 and L4 show weak or negligible protection. Gravimetric tests corroborate the EIS findings, with the corrosion rate decreasing from 14.3 to 1.64 mpy at 300 ppm of L1. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) reveal a smooth, pit-free surface in the presence of the inhibitors, accompanied by a significant drop in oxygen content from 52.11% (wt%) to 5.59% (wt%), confirming the formation of a protective film. Density functional theory (DFT) calculations rationalize the experimental trends, indicating that L1 possesses high polarity and can form two Fe–N chelate rings with short Fe–N distances (2.53–2.62 Å), while L2 combines suitable electronic properties and halogen substitution that favour inhibition in ASW.

The synthesis of electroless Ni–P–TiO₂ composite coatings on marine grade AH36 steel was done using plant-extract-derived titanium dioxide nanoparticles in the present work. TiO₂ nanoparticles were synthesized using Indigofera tinctoria extract as an efficient reducing and capping agent by the green method. Anatase, rutile, and amorphous polymorphs were obtained by controlled temperature calcinations and characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD). They were then dispersed in a premixed bath of electroless Ni–P (including sodium hypophosphite, ammonium chloride, and sodium tri-citrate) with the zwitterionic surfactant for enhanced particle dispersion. One hybrid composite and three single-phase TiO₂ composites with different contents were coated at 85°C for 1 h. The coated samples presented a homogeneous structure in sizes of grain with apparent improvement in microhardness and improved corrosion resistance. A higher TiO₂-added composite coating shows well-defined surface features, as well as superior electrochemical performance. Thickness of the coating was correlated with the phase and elemental composition of particles. The Tafel test showed a marked reduction in the corrosion current density and an increase of anti-corrosion for marine environments. It can be presumed that the green synthesis of Ni–P–TiO₂ is a multilayer, promising economical and environment-friendly approach for enhancing the corrosion resistance and durability of AH36 marine steel.

Bacterial infections continue to pose a major global health threat, especially as antimicrobial resistance keeps rising. In this work, we synthesized a series of novel bis-heterocyclic hybrids built around a quinoxaline core. These compounds came together in good yields and were thoroughly characterized using various spectroscopic methods. We tested their antimicrobial activity against a range of bacterial and fungal strains, and overall, they showed moderate inhibition. Compound 11 stood out as the top performer, knocking down Staphylococcus aureus at an MIC of 1.875 mg/mL, though it was less effective against the others (up to 7.5 mg/mL). To make sense of these results, we ran molecular docking studies, which revealed that compound 11 binds well to key bacterial enzymes involved in virulence and cell-wall integrity, like glucose oxidase, flavohemoprotein, and autolysin. Even though the activity is still modest, this quinoxaline-based bis-heterocycle scaffold looks like a solid foundation for tweaking and boosting potency in future rounds of optimization.