Search Results (3,975)

Organic–inorganic hybrid crystalline materials formed in multicomponent aqueous systems are of interest because their phase behavior and physicochemical properties can be controlled by composition and crystallization conditions. In this study, the phase equilibria and crystallization behavior of the ternary aqueous Ca(ClO₃)₂·2CO(NH₂)₂–CH₂ClCOOH·(C₂H₄OH)₃N–H₂O system were investigated over the temperature range of −24 to 60 °C using the visual-polythermal method. Experimental data obtained for the two boundary binary subsystems and eight internal sections were used to construct the polythermal phase diagram. The diagram revealed distinct crystallization fields corresponding to ice, Ca(ClO₃)₂·2CO(NH₂)₂·2H₂O, CH₂ClCOOH·(C₂H₄OH)₃N, and a separate crystallization region associated with a previously unreported crystalline phase with the proposed composition ClCH₂COOH·Ca(ClO₃)₂·(C₂H₄OH)₃N. The solid phase was isolated from its crystallization region, washed with cold distilled water, dried to constant mass, and characterized by complementary Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM–EDS), thermogravimetric analysis, derivative thermogravimetry, and differential scanning calorimetry (TG–DTG–DSC), and powder X-ray diffraction (PXRD). The experimentally determined Ca²⁺ and ClO₃⁻ contents were reasonably consistent with the proposed composition, while FT-IR spectroscopy revealed characteristic chlorate vibrations and changes in the vibrational environment of the organic component. SEM showed predominantly prismatic and plate-like crystalline morphologies, and EDS confirmed the presence of Ca, Cl, O, C, and N. Thermal analysis demonstrated multistage decomposition, with comparatively good thermal stability below approximately 150 °C. PXRD revealed a diffraction fingerprint distinct from those of the starting components and the corresponding physical mixture. Preliminary indexing of 19 principal reflections was consistent with a tetragonal candidate lattice with a = b = 7.7411(5) Å, c = 24.7182(10) Å, V = 1481.2(5) ų, and M₂₀ ≈ 23.0. The crystallographic analysis is considered preliminary because the diffraction profile was reconstructed from the available pattern and was not subjected to complete structure refinement. Overall, the combined phase-equilibrium, compositional, spectroscopic, morphological, thermal, and diffraction data support the isolation of a distinct organic–inorganic crystalline phase with the proposed composition. Full article

Constructing Schottky heterojunctions with plasmonic components offers a promising route to enhance photocatalytic performance, yet the synergistic roles of the Schottky barrier and localized surface plasmon resonance (LSPR) in pollutant degradation remain insufficiently elucidated. Herein, a series of Ti₃C₂/Ag-Ag₂NCN (TAN) composites with varied Ag loadings was prepared via an in situ precipitation–chemical reduction method. The pseudo-first-order rate constant of the TAN-30 heterojunction reached roughly 7.0 times the value of bare Ag₂NCN, while its tetracycline degradation efficiency under visible light reached 87.0% at 240 min. Moreover, the heterojunction exhibited outstanding reusability over five successive runs. Comprehensive characterizations reveal that the Schottky barrier at the Ti₃C₂/Ag₂NCN interface effectively suppresses photogenerated carrier recombination, while the LSPR effect of metallic Ag⁰ broadens the light absorption range and elevates the local surface temperature, synergistically accelerating charge migration. The dominance of h⁺ and •O₂⁻ among the reactive species was established by both radical trapping assays and ESR spectroscopic analysis. This work provides mechanistic insights into LSPR-enhanced Schottky heterojunctions and offers a rational design strategy for MXene-based photocatalysts toward efficient antibiotic wastewater treatment. Full article

17β-Estradiol (E2), a highly bioactive steroid estrogen, poses potential ecological risks even at trace concentrations in aquatic environments. In this study, a nanoconfined Co-based catalyst (Co@C_in) was employed to activate peracetic acid (PAA) for efficient E2 degradation. Microscopic and spectroscopic characterizations indicated that Co-containing species were highly dispersed within the CNT-based architecture, while the graphitic tubular framework was largely preserved. Compared with PAA alone, CNTs, Co@C_in alone, and the externally loaded Co@C_out/PAA system, Co@C_in/PAA exhibited substantially faster E2 degradation. Pseudo-first-order kinetic analysis further demonstrated the enhanced degradation kinetics of the internally confined system. Importantly, ICP analysis showed comparable Co loadings for Co@C_in and Co@C_out, while Co@C_in retained a markedly higher Co-normalized apparent kinetic activity, indicating that its enhanced performance cannot be explained simply by differences in total Co loading. Moreover, Co@C_in exhibited substantially lower Co leaching than Co@C_out and maintained considerable catalytic activity over five consecutive cycles, demonstrating improved stability of the confined Co species. The degradation performance was influenced by initial E2 concentration, catalyst dosage, PAA concentration, and pH, while Cl⁻ and NO₃⁻ showed negligible effects and humic acid and CO₃²⁻ caused only moderate inhibition. Scavenging experiments and controlled TEMP-EPR measurements with appropriate blank and control systems supported a dominant contribution of singlet oxygen (¹O₂), with radical pathways playing only minor roles. The enhanced performance is therefore associated with the nanoconfined reaction environment, which promotes efficient PAA activation while stabilizing the Co species. This work extends nanoconfinement-regulated PAA oxidation to the treatment of the highly bioactive steroid estrogen E2 and provides a quantitative assessment of the activity–stability advantages of internally confined Co species. Full article

Background: Human respiratory exposure to microplastics (MPs) has recently been demonstrated, but their distribution within thoracic tissues and association with lung malignancy remain poorly characterised. We investigated the presence, burden, morphology, and spectroscopic characteristics of MPs in thoracic tissue specimens and their relationship with lung malignancy. Methods: In this prospective observational study, 50 adults undergoing diagnostic thoracic surgical procedures for suspected lung malignancy were enrolled. Lung, pleural, and mediastinal lymph node specimens underwent contamination-controlled processing, microscopy, and representative particle analysis by confocal micro-Raman spectroscopy. Associations between MPs and clinicopathological variables were analysed. Results: Sixty-two morphologically identified microplastic particles were detected in 50 specimens, with MPs detected in 32 patients (64%). Fragments accounted for 97% of particles, with a median burden of one particle per specimen (IQR, 2). MP detection was significantly more frequent in patients with primary lung malignancy than in patients without primary lung malignancy, including those with metastatic malignancy and benign disease (81.8% vs. 50.0%, p = 0.020), who also exhibited a higher tissue MP burden (p = 0.024). Primary lung malignancy remained independently associated with MP detection after adjustment for age and smoking exposure (OR 4.09, 95% CI 1.06–15.79; p = 0.041). Particle morphology varied by biopsy site, with significantly smaller particles identified in mediastinal lymph nodes (p = 0.006). Synthetic anthropogenic spectral signatures were identified in 71% of particles. Conclusions: MPs are frequently present in human thoracic tissues and are associated with primary lung malignancy. Compartment-specific particle characteristics suggest distinct patterns of respiratory MP deposition and retention, supporting multicentre mechanistic studies. Full article

Fluorescent copper nanoclusters are promising functional nanomaterials; however, controlling their redox behavior through ligand engineering remains challenging. Herein, a multifunctional Vitamin B₁-derived fluorescent copper nanohybrid system was synthesized by a simple one-pot method, where Vitamin B₁ served as both a reducing and stabilizing agent. Spectroscopic and structural characterization supported the formation of ligand-stabilized fluorescent ultrasmall copper species exhibiting blue emission at 465 nm with a quantum yield of 5.7%. The B₁-Cu nanohybrid system displayed pronounced environment-dependent dual redox activity. ORAC analysis revealed a Trolox-equivalent antioxidant capacity of 229.2 ± 5.8 µM TE, compared with 28.1 ± 4.3 µM TE for pure Vitamin B₁, while the ABTS assay yielded an IC₅₀ value of 14.4 ± 0.4 µM, representing an approximately fivefold improvement over Vitamin B₁ (73.7 ± 1.9 µM). In addition, the material exhibited pH-dependent peroxidase-like activity, demonstrating its nanozyme functionality. Biological validation in maize protoplasts showed concentration-dependent intracellular ROS regulation, a pronounced hormetic response, and up to 83% higher GFP-mediated transformation efficiency than the untreated control. These findings demonstrate that ligand-directed modulation of fluorescent copper nanoclusters provides an effective strategy for engineering multifunctional redox-active nanohybrid systems for plant biotechnology and other redox-regulated biointerface applications. Full article

1-Deoxynojirimycin (DNJ), a well-characterized α-glucosidase inhibitor, remains an important target for dose-reduction and formulation strategies. In the present study, we evaluated the individual and combined α-glucosidase inhibitory activities of nine dietary flavonoids with DNJ, quantified synergistic effects using the combination index (CI) method, and elucidated the molecular mechanism through integrated enzyme kinetics, multi-spectroscopic techniques and molecular docking. (+)-Catechin exhibited the strongest inhibitory activity (IC₅₀ = 33.7 ± 2.7 μM), and its combination with DNJ produced synergistic inhibition across all doses (CI < 0.7). Kinetic analysis confirmed that DNJ acted as a competitive inhibitor, while (+)-catechin functioned as a non-competitive inhibitor. Fluorescence quenching assays revealed that (+)-catechin pre-incubation increased the binding affinity of DNJ to α-glucosidase by 393%. Circular dichroism spectroscopy showed that (+)-catechin induced a marked β-sheet-to-α-helix conformational conversion, and co-incubation of both inhibitors produced more secondary structural changes than either inhibitor alone. Molecular docking further confirmed their distinct binding sites. These findings demonstrate that (+)-catechin synergistically potentiates DNJ activity through allosteric conformational modulation, providing an experimental basis for optimizing DNJ-containing formulations. Full article

The phase-pure syntheses of Fe(dca)₂ and Fe(dca)₂(NH₃)₂ have enabled comprehensive investigation of their structural and magnetic properties. Fe(dca)₂ crystallizes in the orthorhombic space group Pnnm, with Fe²⁺ ions octahedrally coordinated by six dca ligands, forming a rutile-like 3D network. Temperature-dependent structural analysis reveals minor distortions and a slight unit cell volume contraction (~2.5 ų) from 300 K to 25 K. Fe(dca)₂(NH₃)₂ crystallizes in the monoclinic space group P2₁/c, featuring two axial ammonia ligands and dca-bridged Fe²⁺ ions forming layers. Magnetic susceptibility measurements of Fe(dca)₂ reveal a ferrimagnetic transition at T_C = 19.1 K, confirmed by SQUID data, Mößbauer spectroscopic measurements and low-temperature neutron diffraction. A magnetic hysteresis at 5 K indicates long-range cooperative magnetic ordering. ATR-IR spectroscopic measurements support the structural models and confirm the chemical composition of both compounds. TGA shows the thermal decomposition of Fe(dca)₂. Full article

Ganoderma lucidum is a medicinal mushroom widely recognized as a source of bioactive metabolites, particularly triterpenoids. Although most studies have focused on fruiting bodies and spores, the potential of cultured mycelial biomass as a source of functional secondary metabolites remains less explored. In this study, we isolated and characterized polycarpol from the mycelia of G. lucidum and evaluated its anti-melanogenic activity in B16F10 murine melanoma cells. Dried mycelia obtained after liquid culture were extracted with 70% ethanol, partitioned with ethyl acetate, and purified by repeated chromatographic separation. The isolated compound was identified as polycarpol by LC–ESI–MS, HR-MS/MS, and NMR spectroscopy, together with comparison with previously reported spectroscopic data. The anti-melanogenic activity of polycarpol was evaluated in α-MSH-stimulated B16F10 murine melanoma cells, a commonly used cellular model of melanogenesis. Polycarpol reduced α-melanocyte-stimulating hormone-induced cellular tyrosinase activity and melanin production at concentrations that did not markedly affect cell viability. Notably, 2 μg/mL (4.54 μM) polycarpol showed a melanin-inhibitory effect comparable to that of arbutin. Western blot analysis showed that polycarpol decreased the expression of microphthalmia-associated transcription factor, tyrosinase, and tyrosinase-related protein-1. In addition, polycarpol suppressed CREB phosphorylation and modulated the MAPK signaling pathways. These findings suggest that polycarpol inhibits melanogenesis through regulation of MITF-associated melanogenic signaling. Overall, this study demonstrates that cultured G. lucidum mycelia can produce anti-melanogenic triterpenoids and highlights cultured mycelial biomass as a controllable fungal material for exploring anti-melanogenic triterpenoids, although further optimization is required to improve production efficiency. Full article

The synthetic industry has shortened human lifespans because of environmental contamination. Numerous physicochemical methods can be used to decompose the released organic contaminants, but heterogeneous photocatalysis stands out among them. The creation of a novel sunlight-active heterogeneous photocatalyst, ZVI@MnFe₂O₄/PTh, for possible degradation of RhB dye is discussed in this study. The nanocomposite was fabricated using the hydrothermal method and in situ polymerization of thiophene. The ternary composite photocatalyst (ZVI@MnFe₂O₄/PTh) and photocatalysts (ZVI@MnFe₂O₄ and MnFe₂O₄/PTh) were well characterized in terms of structure (Fourier transform infrared spectroscopy), morphology (scanning electron microscopy), composition (energy-dispersive X-ray), and crystallinity (X-ray diffraction). UV–visible spectroscopic analysis (Tauc plot) was used to determine the energy bandgaps of catalysts. The characterization study supports the successful assembly of ZVI@MnFe₂O₄ nanoparticles and polythiophene. To evaluate the photocatalytic performance, the photocatalytically helped degradation of Rhodamine B dye from wastewater was also investigated over the new catalysts. The designed heterojunction enhances photogenerated charge separation and stimulates the photocatalytic process. The proposed study’s findings demonstrated that the novel composite’s sunlight-active photocatalytic effectiveness (99% in 90 min at pH 4) was enhanced against the degradation of Rhodamine B dye. Different models were utilized to predict the reaction’s kinetics, and RSM was utilized as a statistical technique to examine the individual and then interaction effects of the influencing parameters. The RSM results were supported by the numerical values of the optimized parameters, which were pH = 4, H₂O₂ = 10 mM, and composite dose = 20 mg/50 mL, utilizing a 100 ppm RhB solution. Full article

Aronia melanocarpa contains abundant phenolic compounds, including procyanidins, flavonols, flavan-3-ols, and phenolic acids, but its pronounced astringency limits its broader use in food applications. Catechol and other oxygen-donor motifs in plant phenolics are known to associate with Fe³⁺ and can support metal–phenolic assembly. In this study, ultrasound-assisted cellulase–pectinase extraction was used to recover an A. melanocarpa polyphenol extract, which was subsequently combined with Fe³⁺ to construct a plant-derived hair dye coating on keratin fibers. Under optimized extraction conditions, the total phenolic yield reached 82.315 mg gallic acid equivalents (GAE)/g dry fruit. A limited targeted LC–MS/MS panel was used to evaluate 12 selected non-anthocyanin phenolic analytes, including procyanidin dimers, a flavan-3-ol, flavonols, and phenolic acids; the contribution of the pH-sensitive anthocyanin fraction was not resolved. Among the tested metal ions, Fe³⁺ produced the strongest chromogenic response. The optimized L-cysteine pretreatment–Fe³⁺ mordanting–polyphenol dyeing sequence produced a ΔE* of 55.42. Adsorption experiments empirically described the uptake behavior of the polyphenol extract, whereas complementary surface, spectroscopic, elemental, diffraction, thermal, and wettability analyses were consistent with the presence of a relatively uniform Fe-containing polyphenol coating at the hair fiber interface. Neither the adsorption-model fits nor the individual characterization techniques uniquely resolved the underlying molecular mechanism. Preliminary HET-CAM, single-exposure dermal, and acute eye irritation assessments showed no obvious acute irritation under the tested conditions. An exploratory image-based analysis examined whether standardized hair tress photographs could approximate a predefined colorimetric score. Because only 30 independent original samples were available and no external validation was performed, this analysis was treated solely as a proof of concept. This laboratory proof-of-concept extends established Fe³⁺–polyphenol assembly chemistry to a compositionally complex A. melanocarpa extract for hair fiber coloration. Further work is required to clarify anthocyanin behavior, simplify the sequential protocol, and benchmark its performance against representative commercial hair dyes. Full article

The previously unreported seven-membered-ring benzanilide derivative, 2-([1,1′-biphenyl]-4-yl)-2,3,4,5-tetrahydro-1H-benzo[c]azepin-1-one (1), was synthesized and structurally characterized by spectroscopic methods and single-crystal X-ray diffraction analysis. The crystal structures of 1 and the known six-membered-ring analogue (2) were compared with that of the corresponding five-membered-ring analogue (3). Increasing ring size was found to induce steric distortions around the amide moiety, resulting in systematic changes in the π-conjugation with the adjacent phenyl groups. This study establishes a structural basis for controlling the electronic properties of ring-fixed benzanilides through ring-size engineering. Full article

1-[(4S)-4-benzyl-1,3-oxazolidin-2-one-3-yl]propyltriphenylphosphonium tetrafluoroborate was synthesized in a two-step procedure starting from (4S)-4-benzyl-3-propionyl-1,3-oxazolidin-2-one. In the first step, (4S)-4-benzyl-3-propionyl-1,3-oxazolidin-2-one was treated with DIBAL-H at −78 °C in DCM and then converted to (4S)-4-benzyl-3-(1-trimethylsilyloxy)propyl-1,3-oxazolidin-2-one with TMSOTf at −78 °C in DCM in the presence of pyridine. Next, the silylated intermediate was transformed to the expected 1-[(4S)-4-benzyl-1,3-oxazolidin-2-one-3-yl]propyltriphenylphosphonium tetrafluoroborate by reaction with Ph₃P·HBF₄ at −40 °C in DCM. The structures of the compounds obtained were confirmed by spectroscopic methods (¹H-, ¹³C{¹H}-, ³¹P{¹H}-NMR, IR) and HRMS analysis. Full article

Natural earth pigments are polymineral materials whose present composition may differ from the source because of selection, grinding, heating, mixing, binder incorporation, and later alteration. This study develops a structured method for separating these contributions and for stating which provenance and degradation claims are supported by available evidence. The material is represented by geological, technological, and degradation components linked to elemental, mineralogical, spectroscopic, microscopic, and colour observations. Provenance is expressed as probabilistic compatibility across source levels, whereas degradation assessment ranks classes of environmental exposure rather than reconstructing a unique history. Published data from Roussillon yellow ochres and commercial and historical green earths are re-analysed as proof-of-concept checks, and a literature-based Herculaneum application illustrates degradation reasoning. The ochre analysis shows that mineralogical and colour relations remain directionally stable under robustness checks and that wet sieving can shift measured composition without eliminating family-level compatibility. The green-earth analysis shows that commercial labels and bulk chemistry alone do not reliably establish celadonite–glauconite family membership, whereas structural and vibrational evidence provides stronger discrimination. The Herculaneum case demonstrates how thermal events and subsequent exposure can alter ochre states. The study provides a practical diagnostic sequence and defines the present limits of inference. Full article

With the growing interest in pandan-based products, bitterness and astringency associated with flavonoids may limit their sensory acceptance. This study investigated the interactions and taste-modulating effects of two milk proteins, β-casein (β-CN) and β-lactoglobulin (β-LG), with two representative bitter flavonoids, catechin (C) and naringin (NAR), in aqueous model systems. Fluorescence spectroscopy showed that both flavonoids produced concentration-dependent quenching of the milk proteins. β-CN exhibited more pronounced interaction-related spectroscopic responses than β-LG, which may be associated with its flexible and intrinsically disordered structure. Molecular docking predicted hydrogen-bonding and hydrophobic interactions in all four protein–flavonoid systems, with catechin and naringin interacting mainly with the internal hydrophobic cavity of β-LG and surface-exposed regions of the β-CN model. Circular dichroism and Fourier-transform infrared spectroscopy indicated ligand-dependent structural changes. For β-LG, catechin slightly decreased the estimated antiparallel and total β-sheet fractions, whereas naringin produced a modest increase. For β-CN, catechin produced a more apparent redistribution between the estimated α-helix and β-sheet fractions, while naringin caused comparatively smaller changes. Electronic tongue measurements showed that the addition of the milk proteins reduced the bitterness- and astringency-related sensor responses of catechin and naringin. Under the tested conditions, β-CN produced greater attenuation of these responses than β-LG, while the umami-related response remained comparatively high. These findings support the potential application of milk proteins as taste-modulating components in flavonoid-containing dairy formulations, although validation in real food matrices is required. Full article

Metal-graphitic nanocapsules are an emerging class of metal-graphitic hybrid nanomaterials, typically consisting of a metal core confined within a single- or few-layer graphitic shell. This unique core–shell architecture integrates the tunable physicochemical properties of metal nanomaterials with the chemical stability, Raman activity, fluorescence-quenching capability, and surface functionalization capacity of graphitic materials. In particular, the metal core can provide plasmonic enhancement as well as magnetic or catalytic auxiliary functions, while the chemically protective graphitic shell protects the core from harsh environments and provides intrinsic Raman bands that can serve as internal standards under well-controlled conditions. These features make metal-graphitic nanocapsules highly attractive as robust nanoprobes for molecular spectroscopy-based chemical analysis, biosensing, and targeted diagnosis. In this review, we first summarize the synthesis strategies, formation mechanisms, and key properties of representative metal-graphitic nanocapsules. We then discuss recent advances in their use across representative analytical and biomedical scenarios, with emphasis on the integration of spectroscopic readouts with targeted recognition strategies. Particular attention is given to how the metal core and graphitic shell cooperatively enhance signal generation, molecular enrichment, selective recognition, environmental stability, internal calibration, and reliable in situ diagnosis in real samples and living systems. Finally, we discuss current challenges and future perspectives for developing metal-graphitic nanocapsules as versatile platforms for molecular spectroscopy-based analysis and diagnosis. Full article