Search Results (613)

X-ray absorption spectroscopy (XAS) and X-ray emission spectroscopy (XES) are analytical techniques enabling precise analysis of the electronic structure and local atomic environment in chemical compounds and materials. Their application spans materials science, chemistry, biology, and environmental sciences, supporting studies on catalytic mechanisms, redox processes, and metal speciation. A key advantage of both techniques is element selectivity, allowing the analysis of specific elements without matrix interference. Their high sensitivity to chemical state and coordination enables determination of oxidation states, electronic configuration, and local geometry. These methods are applicable to solids, liquids, and gases without special sample preparation. Modern XAS and XES studies are typically performed using synchrotron radiation, which provides an intense, monochromatic X-ray source and allows advanced in situ and operando experiments. Sub-techniques such as XANES (X-ray absorption near-edge structure), EXAFS (Extended X-ray Absorption Fine Structure), and RIXS (resonant inelastic X-ray scattering) offer enhanced insights into oxidation states, local structure, and electronic excitations. Despite their broad scientific use, applications in pharmaceutical research remain limited. Nevertheless, recent studies highlight their potential in analyzing crystalline active pharmaceutical ingredients (APIs), drug–biomolecule interactions, and differences in drug activity. This review introduces the fundamental aspects of XAS and XES, with an emphasis on practical considerations for pharmaceutical applications, including experimental design and basic spectral interpretation. Full article

Nanocrystals of Eu-doped GaN powders are produced via pyrolysis of a viscous compound made from europium and gallium nitrates. Furthermore, carbohydrazide is used as a fuel and toluene as a solvent; subsequently, a crucial nitridation process is carried out at 1000 °C for one hour. A slight shift of 0.04 degrees toward larger angles was observed for the X-ray diffraction patterns in the Eu-doped GaN powders regarding the undoped GaN powders, while Raman scattering also displayed a slight shift of 10.03 cm⁻¹ toward lower frequencies regarding the undoped GaN powders for the vibration mode, E₂(H), in both cases indicating the incorporation of europium atoms into the GaN crystal lattice. A scanning electron microscope micrograph demonstrated a surface morphology for the Eu-doped GaN with a shape similar to elongated platelets with a size of 3.77 µm in length. Energy-dispersive spectroscopy and X-ray photoelectron spectroscopy studies demonstrated the europium elemental contribution in the GaN. The X-ray photoelectron spectroscopy spectrum for gallium demonstrated the binding energies for Ga 2P_3/2, Ga 2P_1/2, and Eu 3d_5/2, which could indicate the incorporation of europium into the GaN and the bonding between gallium and europium atoms. The transmission electron microscope micrograph showed the presence of nanocrystals with an average size of 9.03 nm in length. The photoluminescence spectrum showed the main Eu³⁺ transition at 2.02 eV (611.69 nm) for europium emission energy, corresponding to the ⁵D₀ ⟶ ⁷F₂ transition of the f shell, which is known as a laser transition. Full article

We present a novel approach for the synthesis of crystalline zinc oxide (ZnO) nanopowders based on the direct interaction of high-power microwave radiation with a zinc wire in atmospheric air. The process utilizes a localized microwave-induced plasma to rapidly vaporize the metal, followed by oxidation and condensation, resulting in the deposition of ZnO nanostructures on glass substrates. Plasma diagnostics confirmed the generation of a plasma in local thermodynamic equilibrium (LTE), characterized by high electron temperatures. Optical emission spectroscopy highlighted atomic species such as ZnI, ZnII, OI, OII, and NI, as well as molecular species including OH, N₂ and O₂. The spectral fingerprint of N₂ molecules reveals the presence of high energy electrons, while the persistent occurrence of OI and OII emission lines throughout the plasma spectrum reveals that ZnO formation is mainly driven by the continuous dissociation of molecular oxygen. High crystallinity and chemical purity of the synthesized ZnO nanoparticles were confirmed through SEM, TEM, XRD, FTIR, and EDX characterization. The resulting nanorods exhibit a rod-like morphology, with diameters ranging from 12 nm to 63 nm and lengths between 58 nm and 354 nm. This low-cost, high-yield method offers a scalable and efficient route for metal oxide nanomaterial fabrication via direct metal–microwave coupling, providing a promising alternative to conventional physical and chemical synthesis techniques. Full article

Iron deficiency anemia (IDA) remains a global health challenge. This study pioneers the use of humic substances (HS) as natural, biocompatible macroligands to develop safer and more effective nanoferrotherapeutics. We synthesized a series of nanoscale Fe(III) oxyhydroxide complexes stabilized by different HS, employing various solvents (ethanol, isopropanol, and acetone) and precipitation methods to isolate fractions with optimized properties. The nanocomposites were comprehensively characterized using inductively coupled plasma atomic emission spectrometry, total organic carbon analysis, X-ray diffraction, transmission electron microscopy, and Mössbauer spectroscopy. Cytotoxicity and iron bioavailability of all HS-Fe(III) formulations were assessed in Caco-2 intestinal epithelial cells. The type of HS and precipitation conditions significantly influenced the nanocomposites’ properties, yielding spherical nanoparticles (1–2 nm) of ferrihydrite or goethite. Physicochemical analysis confirmed that solvent-driven fractionation effectively tailored the nanocomposites’ size, crystallinity, and elemental composition. All HS-Fe(III) formulations demonstrated exceptional cytocompatibility, starkly contrasting the significant cytotoxicity of the reference drug Ferrum Lek^®. Several complexes, particularly CHSFe-Et67, surpassed Ferrum Lek^® in cellular iron uptake efficiency. We conclude that HS are a highly promising platform for developing effective and safe iron-delivery nanoferrotherapeutics, leveraging their natural polyfunctionality to enhance bioavailability and mitigate toxicity. Full article

Changes in the habitat of wild mallard ducks (Anas platyrhynchos L.) and thus in their diet can result in significant differences in the content of sodium and potassium in their tissues and organs. There is little data in the available literature regarding the qualitative analysis of mallard meat and organs. The aim of the study was to determine the sodium and potassium content in biological material (breast muscle, leg muscles, and liver) from wild mallards and the effect of sex and place of origin (hunting district) on these parameters. Sodium and potassium in the biological material were analyzed by inductively coupled plasma atomic emission spectroscopy (ICP-OES). The sodium and potassium levels in the tissues were shown to be influenced by the sex of the mallards and the site where they were harvested. Sodium content was significantly higher in the liver of male mallards than in females. In most cases, the tissues and organs of mallards harvested in the Siedlce hunting district had higher levels of sodium and potassium, apart from potassium content in the breast muscle. This may indicate greater abundance of these elements in this district. Full article

A para-substituted 1,10-phenanthroline ligand, 2-(4-methylphenoxy)-1,10-phenanthroline (L24), was synthesized and structurally characterized. Complexes with Eu³⁺, Tb³⁺, Sm³⁺, and Dy³⁺ were obtained in a 2:1 ligand-to-metal ratio and analyzed using single-crystal x-ray diffraction, photoluminescence spectroscopy, and TD-DFT calculations. Coordination via the phenanthroline nitrogen atoms, combined with steric asymmetry from the para-methylphenoxy group, induces low-symmetry environments favorable for electric-dipole transitions. Excited-state lifetimes reached 2.12 ms (Eu³⁺) and 1.12 ms (Tb³⁺), with quantum yields of 42% and 68%, respectively. The triplet-state energy of L24 (22,741 cm⁻¹) aligns well with emissive levels of Eu³⁺ and Tb³⁺, consistent with Latva’s criterion. Fluorescence titrations indicated positively cooperative complexation, with association constants ranging from 0.60 to 1.67. Stark splitting and high ⁵D₀ → ⁷F₂/⁷F₁ intensity ratios (R₂ = 6.25) confirm the asymmetric coordination field. The para-methylphenoxy substituent appears sufficient to lower coordination symmetry and strengthen electric-dipole transitions, offering a controlled route to enhance photoluminescence in Eu³⁺ and Tb³⁺ complexes. Full article

Tantalum nitride (TaN) is a typical transition metal nitride characterized by a wide range of tunable resistivity. Low-resistance TaN even exhibits a resistivity similar to that of metals. Given that electrical resistance influences secondary electron emission (SEE) behavior, this study investigates the relationship between TaN film resistivity and SEE characteristics. Five TaN films were deposited by varying the N₂ gas flow rate during sputtering. Morphological analyses revealed that the film thicknesses ranged from approximately 197 to 281 nm. X-ray photoelectron spectroscopy (XPS) results indicated that the Ta:N atomic ratio of the films ranged from approximately 0.53 to 0.87. Furthermore, XPS detected non-adsorbed oxygen on the surfaces of the TaN films, and more detailed XPS analysis revealed the formation of TaON compounds on the surfaces due to oxygen exposure. X-ray diffraction patterns confirmed that the TaN films contained two crystal phases: Ta₂N (002) and TaN (200). Sheet resistivity tests showed that the resistivity of the TaN films ranged from 5.67 × 10⁻³ to 2.43 Ω·cm. Furthermore, the lower the Ta:N atomic ratio was, the lower the electrical resistivity of the films became. SEE coefficient (SEEC) showed a clear positive correlation with the films’ electrical resistivity. Specifically, films with lower resistivity exhibited reduced SEEC values. When the N₂ gas flow rate was 16 sccm (N₂:Ar = 16:0), the film exhibited the smallest SEEC (maximum ~1.88); when the N₂ flow rate was 0 sccm (N₂:Ar = 0:16), the film showed the largest SEEC (maximum ~2.25). This research provides valuable references for expanding the application of TaN films in engineering scenarios involving electrical resistivity adjustment and SEE applications. Full article

In recent years, the generation of circularly polarized attosecond pulses has garnered significant attention due to their potential applications in ultrafast spectroscopy and, notably, in chiral-sensitive molecular detection. The traditional methods for generating such pulses often involve complex laser configurations or specially engineered targets, limiting their experimental feasibility. In this study, we present a streamlined and effective approach to producing circularly polarized attosecond pulses by employing a linearly polarized laser field in conjunction with a stereosymmetric linear molecule, 1-butyne (C₄H₆). The generation of high-order harmonics by this molecular system reveals a distinct plateau in the perpendicular polarization component, which facilitates the generation of isolated attosecond pulses with circular polarization. Through a detailed analysis of the time-dependent charge density dynamics across atomic sites, we identify the atoms primarily responsible for the emission of circularly polarized harmonics in the plane orthogonal to the driving field. Moreover, we explore the role of multi-orbital contributions in shaping the polarization properties of the harmonic spectra. Our findings underscore the importance of molecular symmetry and the electronic structure in tailoring the harmonic polarization, and they demonstrate a viable pathway for using circularly polarized attosecond pulses to probe molecular chirality. This method offers a balance between simplicity and performance, opening new avenues for practical applications in chiral recognition and ultrafast stereochemical analysis. Full article

In this work, ZnO nanorods were grown on vertically aligned and randomly aligned silica nanosprings using the hydrothermal method. The initial step was the deposition of a ZnO seed layer by atomic layer deposition to promote nucleation. For hydrothermal growth, equimolar (0.2 M) solutions of Zinc nitrate hexahydrate and hexamethylene tetraamine prepared in DI water were used. The ZnO NR grown on the VANS were flower-like clusters, while for the RANS, the ZnO NR grew radially outward from the individual nanosprings. The lengths and diameters of ZnO NR grown on VANS and RANS were 175 and 650 nm, and 35 and 250 nm, respectively. Scanning electron microscopy confirmed the formation of ZnO nanorods, while X-ray diffraction and Raman spectroscopy verified that they have a hexagonal wurtzite crystal structure with preferential growth along the c-axis. X-ray photoelectron spectroscopy, in conjunction with in vacuo annealing, was used to examine the surface electronic structure of ZnO nanorods and defect healing. Photoluminescence of the ZnO nanorods indicates high crystal quality, as inferred from the weak defect band relative to strong excitonic band edge emission. Full article

Groundwater quality in arid and semi-arid regions of Morocco is under increasing pressure due to both anthropogenic influences and climatic variability. This study investigates the physicochemical and heavy metal characteristics of groundwater across four Moroccan regions (Tangier-Tetouan-Al Hoceima, Oriental, Souss-Massa, and Marrakech-Safi) known for being argan tree habitats. Thirteen groundwater samples were analyzed for twenty-five parameters, including major ions, nutrients, and trace metals. Elevated levels of ammonium, turbidity, electrical conductivity, and dissolved oxygen were observed in multiple samples, surpassing Moroccan water quality standards and indicating significant quality deterioration. Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) detected arsenic concentrations exceeding permissible limits in sample AW11 alongside widespread lead contamination in most samples except AW5 and AW9. Spatial patterns of contamination were characterized using Principal Component Analysis (PCA), Hierarchical Cluster Analysis (HCA), K-means clustering, and GIS-based Inverse Distance Weighted (IDW) interpolation. These multivariate approaches revealed marked spatial heterogeneity and highlighted the dual influence of geogenic processes and anthropogenic activities on groundwater quality. To assess consumption suitability, a Water Quality Index (WQI) and Human Health Risk Assessment were applied. As a result, 31% of samples were rated “Fair” and 69% as “Good”, but with notable non-carcinogenic risks, particularly to children, attributable to nitrate, lead, and arsenic. The findings underscore the urgent need for systematic groundwater monitoring and management strategies to safeguard water resources in Morocco’s vulnerable dryland ecosystems, particularly in regions where groundwater sustains vital socio-ecological species such as argan forests. Full article

Mining activity in Peru generates environmental liabilities with the potential to release toxic metals into the environment. This study conducted a comprehensive physical, chemical, mineralogical, and toxicological characterization of ten active and inactive tailings samples from the Arequipa region in southern Peru. Particle size distribution analysis, inductively coupled plasma atomic emission spectroscopy (ICP-AES), scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS), and the Toxicity Characteristic Leaching Procedure (TCLP) followed by ICP-MS were employed. The results revealed variable particle size distributions, with the sample of Secocha exhibiting the finest granulometry. Chemically, 8 out of 10 samples exhibited concentrations of at least two metals surpassing the Peruvian Environmental Quality Standards (EQS) for soils with values reaching >6000 mg/kg of arsenic (Paraiso), 193.1 mg/kg of mercury (Mollehuaca), and 2309 mg/kg of zinc (Paraiso). Mineralogical analysis revealed the presence of sulfides such as arsenopyrite, cinnabar, galena, and sphalerite, along with uraninite in the Otapara sample. In the TCLP tests, 5 out of 10 samples released at least two metals exceeding the environmental standards on water quality, with concentrations up to 0.401 mg/L for mercury (Paraiso), 0.590 mg/L for lead (Paraiso), and 9.286 mg/L for zinc (Kiowa Cobre). These results demonstrate elevated levels of Potentially Toxic Elements (PTEs) in both solid and dissolved states, reflecting a critical geochemical risk in the evaluated areas. Full article

Background/Objectives: Airborne viral diseases pose a health risk, due to which there is a growing interest in developing filter materials capable of capturing fine particles containing virions from the air and that also have a virucidal effect. Nanofiber membranes made of poly(vinylidene fluoride) dissolved in N,N-dimethylacetamide and functionalized with copper, silver, and zinc nanoclusters were fabricated via electrospinning. This study aims to evaluate and compare the virucidal effects of nanofibers functionalized with metal nanoclusters against the human influenza A virus A/WSN/1933 (H1N1) and SARS-CoV-2. Methods: A comprehensive characterization of materials, including X-ray diffraction, scanning electron microscopy, microwave plasma atomic emission spectroscopy, thermogravimetric analysis, contact angle measurements, nitrogen sorption analysis, mercury intrusion porosimetry, filtration efficiency, and virucidal tests, was used to understand the interdependence of the materials’ physical characteristics and biological effects, as well as to determine their suitability for application as antiviral materials in air filtration systems. Results: All the filter materials tested demonstrated very high particle filtration efficiency (≥98.0%). The material embedded with copper nanoclusters showed strong virucidal efficacy against the SARS-CoV-2 alpha variant, achieving an approximately 1000-fold reduction in infectious virions within 12 h. The fibrous nanowire polymer functionalized with zinc nanoclusters was the most effective material against the human influenza A virus strain A/WSN/1933 (H1N1). Conclusions: The materials with Cu nanoclusters can be used with high efficiency to passivate and kill the SARS-CoV-2 alpha variant virions, and Zn nanoclusters modified activated porous membranes for killing human influenza A virus A7WSN/1933 (H1N1) virions. Full article

In this work, hybrid membranes were fabricated by depositing polyvinyl chloride (PVC) fibers onto PET track-etched membranes (TeMs) using the electrospinning technique. The resulting structures exhibited enhanced hydrophobicity, with contact angles reaching 155°, making them suitable for applications in both water–oil mixture separation and membrane distillation processes involving low-level liquid radioactive waste (LLLRW), saline solutions, and natural water sources. The use of hybrids of TeMs and nanofiber membranes has significantly increased productivity compared to TeMs only, while maintaining a high degree of purification. Permeate obtained after MD of LLLRW and river water was analyzed by conductometry and the atomic emission spectroscopy (for Sr, Cs, Al, Mo, Co, Sb, Ca, Fe, Mg, K, and Na). The activity of radioisotopes (for ¹²⁴Sb, ⁶⁵Zn, ⁶⁰Co, ⁵⁷Co, ¹³⁷Cs, and ¹³⁴Cs) was evaluated by gamma-ray spectroscopy. In most cases, the degree of rejection was between 95 and 100% with a water flux of up to 17.3 kg/m²·h. These membranes were also tested in the separation of cetane–water emulsion with productivity up to 47.3 L/m²·min at vacuum pressure of 700 mbar and 15.2 L/m²·min at vacuum pressure of 900 mbar. Full article

Osteosarcoma (OSA) is the most common primary bone malignancy in dogs, characterized by aggressive growth and high metastatic potential. Despite advances in treatment, the prognosis for affected animals remains poor, mainly due to metastatic disease. Metastasis is a complex process that involves forming new blood vessels in the primary tumor (angiogenesis), intravasation, the transport of cancer cells to other locations, extravasation, and the growth of cancer cells in the secondary site. Gold nanoparticles (AuNPs), due to their unique physicochemical properties, are considered promising tools in cancer therapy, both as drug delivery systems and potential anti-metastatic agents. Previously, it has been demonstrated that 500 µg/mL glutathione-stabilized gold nanoparticles (Au-GSH NPs) inhibit cancer cell extravasation—one of the steps of the metastatic cascade. This study aimed to evaluate the anti-metastatic properties of Au-GSH NPs through their influence on OSA cell migration, proliferation, and colony formation in vitro, as well as their antiangiogenic properties on the chick embryo chorioallantoic (CAM) model. Additionally, we investigated whether these effects are associated with changes in alpha-2-macroglobulin (A2M) expression, as it was previously demonstrated to play an essential role in the metastatic cascade. Au-GSH NPs significantly inhibited migration and colony formation in canine osteosarcoma cells (from OSCA-8, OSCA-32, and D-17 cell lines) at 200 µg/mL concentrations. Interestingly, at 500 µg/mL, Au-GSH NPs inhibited angiogenesis on the CAM model and cancer cell migration, but fewer colonies were formed. These results may be directly related to the higher efficiency of Au-GSH NPs uptake by OSA cells at the dose of 200 μg/mL than at the dose of 500 μg/mL, as demonstrated using Microwave Plasma Atomic Emission Spectroscopy (MP-AES). Moreover, this is the first study that demonstrates a significant increase in A2M expression in cancer cells after Au-GSH NPs treatment. This study provides new insight into the potential use of Au-GSH NPs as anti-metastatic agents in canine osteosarcoma, indicating that their anti-metastatic properties may be related to A2M. However, further in vitro and in vivo studies are needed to explore the molecular mechanism underlying these effects and to evaluate the clinical relevance of AuNPs in veterinary oncology. Full article

This work presents the synthesis, characterisation, photophysical properties, time-resolved spectroscopic behaviour, and biological evaluation of two structurally distinct heavy-atom-free BODIPY-anthracene dyads (BDP-1) and the newly designed 2,6-bis[1-(tert-butyl) 4-(prop-2-yn-1-yl) piperazine-1,4-dicarboxylate] BODIPY-anthracene (BDP-2), incorporating 2,6-alkynyl-piperazine substituents for potential application in antimicrobial photodynamic therapy. BDP-1 exhibits absorption and emission maxima at 507 nm and 516 nm, respectively, with a Stokes shift of 344 cm⁻¹ in dichloromethane (DCM), characteristic of unsubstituted BODIPYs. In contrast, BDP-2 undergoes a red-shift in the absorption maximum to 552 nm (Stokes shift of 633 cm⁻¹), which is attributed to the extended conjugation from the introduction of the alkyne groups. Time-resolved infrared spectroscopy confirmed efficient spin-orbit charge transfer intersystem crossing, and nanosecond transient absorption studies confirmed the formation of a long-lived triplet state for BDP-2 (up to 138 µs in MeCN). A binding constant (K_b) of 9.6 × 10⁴ M⁻¹ was obtained for BDP-2 when titrated with bovine serum albumin (BSA), which is higher than comparable BODIPY derivatives. BDP-2 displayed improved hemocompatibility compared to BDP-1 (<5% haemolysis of human erythrocytes up to 200 μg·mL⁻¹). Antimicrobial activity of BDP-1 and BDP-2 was most potent when irradiated at 370 nm compared to the other wavelengths employed. However, BDP-2 did not retain the potent (6 log) and rapid (within 15 min) eradication of Staphylococcus aureus achieved by BDP-1 under irradiation at 370 nm. These findings demonstrate the rational design of BDP-2 as a biocompatible, and heavy-atom-free BODIPY offering promise for targeted antimicrobial photodynamic therapeutic applications. Full article