Search Results (23,205)

Three cerium-based metal–organic frameworks (MOFs), Ce-BDC, Ce-BDC-NH₂, and Ce-BTC, were used as catalysts for the hydroxylation of several organic compounds, including those not relevant to environmental or biological systems. Structural characteristics were validated by FT-IR spectroscopy, while SEM imaging demonstrated rod-like morphologies of 100–200 nm in width for Ce-BDC-NH₂ and 50–100 nm for Ce-BTC. The optical properties, ascertained using diffuse reflectance spectra and Tauc analysis, revealed bandgaps of 3.0 eV, 2.9 eV, and 3.6 eV for Ce-BDC, Ce-BDC-NH₂, and Ce-BTC, respectively. Catalytic investigations revealed that Ce-MOFs effectively convert phenol into 1,4-dihydroxybenzene with an efficiency of 86–99%, as confirmed by UV–Vis spectroscopy and HPLC analysis using an authentic hydroquinone (1,4-dihydroxybenzene) standard. The Ce-MOFs efficiently oxidize the dyes methylene blue (MB) and Congo red (CR) and also promote the hydroxylation of L-tyrosine, indicating their relevance to biologically significant substrates. The high catalytic performance of Ce-MOF highlights the potential of Ce-based materials for environmental remediation, chemical transformation, and sustainable wastewater treatment. Full article

Hair loss affects over half of adults by age 70 and represents a major determinant of overall hair health, imposing significant psychosocial burden across genders. Nutritional factors play a critical role in follicle biology, yet targeted strategies remain underexplored. This comprehensive review examines five key hair-constituent macromolecules—type I collagen, elastin, keratin, ceramides, and melanin—and their physiological and clinical impacts on hair structure, density, shining, and growth. We conducted a structured literature search in PubMed and Google Scholar through January 2025, selecting in vitro studies, animal experiments, and human clinical trials that evaluated each macromolecule’s effects on follicular function and hair fiber integrity. Type I collagen enhances dermal papilla cell proliferation, upregulates Wnt/β-catenin and growth factors, and improves hair thickness and breakage resistance in randomized controlled trials. Keratin hydrolysates replenish cortical protein, reinforce disulfide cross-links, and reduce telogen shedding, with clinical studies demonstrating 30–50% decreases in hair loss and gains in tensile strength. Oral ceramide formulations restore the cuticular lipid barrier, shift follicles toward anagen, and increase hair density in double-blind trials. Although direct clinical data on melanin supplementation are lacking, ex vivo and animal models confirm its role as a UV-protective pigment, preserving keratin integrity and color fastness. Together, these macromolecules constitute a coherent framework for hair health, and clinical studies increasingly provide evidence that their combined or parallel application can meaningfully enhance hair density, strength, shine, and resilience. Full article

Aquifers are increasingly threatened by the uncontrolled release of non-biodegradable chemicals derived from anthropogenic activities. The development of new remediation strategies has therefore focused on the use of sustainable adsorbent materials, including synthetic organic hydrogels and biochars produced from agricultural residues. In this study, the removal of two organic pollutants, the herbicide Metribuzin (MEB) and Propyl Paraben (PrP), from aqueous environments was investigated using negatively charged hydrogels and biochars derived from lime peel, respectively. Propyl Paraben (PrP) and Metribuzin (MEB) are among the pollutants frequently found in aquatic environments, and the effective and sustainable removal approaches remain under investigation. The hydrogels studied (P(DMAM co-ANax)) were based on sodium methacrylate (ANa) copolymerized with N,N-dimethylacrylamide (DMAM). The adsorption performance of the materials was evaluated through UV-Visible absorption spectrophotometry and High-Performance Liquid Chromatography (HPLC). The results of this study showed that the hydrogel achieved a very high removal efficiency for MEB, which was over 80% for the concentration range studied (max $Q_e$ = 0.386 mg/g). Similar behavior was also recorded for the biochar from lime peel, which achieved almost complete removal of PrP (~100%) at the lowest concentrations of the contaminant (5 mg/L) and maintained high removal rates (78%) at 10 mg/L (max $Q_e$ = 0.187 mg/g). These results demonstrate the potential of both types of materials to efficiently remove the studied contaminants from water, indicating their suitability for environmental remediation applications. This work contributes to the development of cost-effective and eco-friendly adsorbents for the treatment of water pollution caused by emerging organic compounds. Full article

The technological promise of nonlinear optical (NLO) compounds has stimulated intense interest in optoelectronic devices, data storage, photonics, and anticancer therapy. Thiosemicarbazone ruthenium materials are of growing interest because of their tunable ligand framework and coordination sphere, allowing fine control over geometry, electronics, and functional properties. Here, we report an N-substituted salicylaldehyde thiosemicarbazone ligand and a series of octahedral Ru(III) complexes bearing triphenylphosphine or triphenylarsine and halide (Cl, Br) co-ligands. The complexes were characterized by elemental analysis, FT-IR, UV–Vis, EPR, mass spectrometry, and magnetic susceptibility measurements, which together confirm NS-chelation to a low-spin Ru(III) center in a distorted octahedral environment. Their photophysical and NLO responses were assessed by UV–Vis spectroscopy and powder second-harmonic generation measurements (Kurtz–Perry method), revealing promising NLO behavior. In parallel, antioxidant activity and in vitro anticancer effects against HeLa cells were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cytotoxicity assays. These results provide insight into ligand-controlled structure–activity relationships, in which the halide (Cl/Br) and ancillary triarylphosphine co-ligands regulate electronic interactions and lipophilicity and ultimately increase biological performance, underscoring the dual materials and medicinal potential of these Ru(III) complexes. Full article

Glasses with compositions (52.5 − x/2)B₂O₃:(12.5 − x/2)SiO₂:25La₂O₃:5ZnO:5CaO:0.5Eu₂O₃:xWO₃, x = 0, 2.5, 5, 7.5, 10, 20 (mol%) were prepared by conventional melt-quenching method and investigated by X-ray diffraction analysis, DSC analysis, DR-UV-Vis spectroscopy and photoluminescence spectroscopy. Physical parameters like density, molar volume, oxygen molar volume and oxygen packing density were also determined. Their values, as well as DR-UV-Vis spectroscopy results, indicate that the tungstate ions incorporate into the base borosilicate glass as tetrahedral WO₄ and octahedral WO₆ groups. With increasing WO₃ content over 5 mol%, WO₆ units are progressively linked to each other by W-O-W bonds, leading to the formation of a more connected and homogeneous glass network. Glasses are characterized by a high glass transition temperature (over 650 °C) and good thermal stability. The emission intensity of the Eu³⁺ ion increases with the introduction of WO₃ due to the occurrence of non-radiative energy transfer from the tungstate groups to the active ion. The most intense luminescence peak observed at 612 nm suggests that the glasses are potential materials for red emission. Full article

Monitoring peptide and protein self-association is essential for understanding biological function, formulation stability, and aggregation mechanisms. While size-exclusion chromatography (SEC) is routinely used to quantify protein-size variants under native conditions, its hyphenation to high-resolution mass spectrometry (HRMS) for simultaneous structural characterization remains limited. Here, we report the development and validation of a robust SEC-UV/HRMS method optimized for native-like analysis of bovine serum albumin (BSA) monomers and higher-order oligomers using standard-flow electrospray ionization. Systematic evaluation of source parameters, mobile-phase composition, and chromatographic conditions enabled retention of native BSA structure, minimized in-source unfolding, and enhanced MS sensitivity, allowing detection of oligomers up to the heptamer. A short, narrow-bore 200 Å UHPLC SEC separation column was used. Low-flow separations (~0.05 mL/min) enabled efficient ionization and 10 min run times. An accelerated 60 °C stress-testing protocol demonstrated that SEC-MS can semi-quantitatively monitor oligomerization dynamics, complementing UV-based quantification and revealing transient species not resolved by UV alone. The method showed acceptable linearity, precision, and sample stability, and comparison with SEC-RALS/LALS confirmed molecular-weight trends across aggregation states. Overall, the developed SEC-UV/HRMS workflow provides a rapid, sensitive, and widely accessible approach for UV-based quantification of monomer- and HRMS-based characterizing protein aggregation in research and quality control in pharmaceutical laboratories. Full article

Sunscreens are essential for photoprotection, but conventional inorganic UV filters raise concerns regarding marine toxicity. This study investigated hydroxyapatite (HAp) derived from skipjack, tongol, and salmon bone waste as a potential synergistic booster for Tinosorb^® S (TS). HAp powders were prepared via alkaline treatment and calcination at 900 °C. XRD and XRF results confirmed highly crystalline HAp as the dominant phase. While 10% HAp alone provided negligible UV protection, a pronounced synergistic effect was observed in 1:1 hybrid formulations (5% HAp:5% TS), significantly enhancing Sun Protection Factor (SPF) and Ultraviolet A Protection Factor (UVAPF). Notably, particle-size refinement of salmon-derived HAp (SM–HAp) yielded an SPF of approximately 35, comparable to a commercial HAp counterpart. This improvement was suggested to be associated with enhanced dispersion, film uniformity, and particle–matrix interactions, which might contribute to achieving PA++++ protection. All formulations complied with microbiological and heavy metal safety standards. These results indicated that fish bone-derived HAp could potentially serve as a viable and sustainable functional additive derived from marine biowaste for the development of high-performance hybrid sunscreens, promoting biomaterial valorization in the cosmetic industry. Full article

The growing pollution caused by plastics with slow degradation kinetics is demanding the search for biodegradable alternatives. Starch-based films are a promising option, but their practical application may be limited by their potential susceptibility to rapid ultraviolet (UV) exposure degradation. This study evaluates the effect of prolonged UV-C irradiation (254 nm, 168 h) on plasticizer-free films derived from the starch of an Ecuadorian potato Solanum tuberosum (Chola variety). Films formulated at 3% and 5% (w/v) starch were characterized before and after UV exposure. The analysis includes the evaluation of optical, mechanical, and physicochemical properties, along with Fourier Transform Infrared spectroscopy (FTIR) and atomic force microscopy (AFM) for nanoscale surface inspection. UV irradiation increased the opacity of the films but reduced slightly their tensile strength, elongation at break, moisture content, and total soluble matter. In contrast, the elastic modulus remained relatively high. FTIR analysis revealed no significant formation of new functional groups. AFM measurements indicated that irradiation caused only minor nanoscale alterations in the same film regions. These alterations were more pronounced in films with higher starch concentrations. The results demonstrate that UV-C exposure induces minor structural adjustments in plasticizer-free starch films derived from the Chola variety, without compromising their fundamental integrity. Consequently, this work advances the understanding of the environmental stability of these films and supports their potential application as sustainable materials, even in conditions involving UV exposure. Full article

Background/Objectives: Psychological stress triggers excessive melanin deposition via neuroendocrine pathways, yet targeted interventions for stress-induced hyperpigmentation remain limited. Salidroside (SAL) exhibits established depigmenting effects in UV-induced models and possesses neuroprotective properties. This study investigated SAL’s efficacy in psychological stress-induced hyperpigmentation and elucidated its underlying mechanisms. Methods: B16F10 melanocytes, C57BL/6J mice, zebrafish, and human foreskin organ cultures were subjected to stress factor (Substance P/cortisol) or α-MSH/IBMX stimulation to model psychological stress-induced and canonical cAMP-driven hyperpigmentation, respectively. Melanin content, tyrosinase activity, melanosome maturation (transmission electron microscopy/HMB45 staining), and melanogenic protein/mRNA expression were assessed. Drug Affinity Responsive Target Stability (DARTS) assays, molecular docking, and SEC23A siRNA knockdown were employed to identify and validate SAL’s molecular target and downstream signaling pathways. Results: SAL dose-dependently reduced melanin content, tyrosinase activity, and TYR/TRP-1/DCT expression in SP/Cort-stimulated melanocytes, exhibiting greater potency (200 μM) than in IBMX-induced models (400 μM). SAL reversed SP/Cort-induced hyperpigmentation in human skin explants, zebrafish, and C57BL/6J mice, and normalized melanosome number/maturation. DARTS and molecular docking identified SEC23A as a direct SAL-binding target. SP/Cort specifically upregulated SEC23A, which SAL suppressed. SAL concurrently activated the SEC23A-p-ERK-MITF axis and inhibited the NK1R-p38-MITF axis in the stress model. SEC23A knockdown potentiated SAL’s anti-melanogenic effects specifically in SP/Cort-stimulated cells. Conversely, in IBMX-induced models, SEC23A remained unchanged, and SAL acted via PKA/CREB, PI3K/AKT, and Wnt/β-catenin pathways. Conclusions: SEC23A is a novel core target in psychological stress-induced hyperpigmentation. SAL selectively binds SEC23A to inhibit stress-induced melanogenesis via dual ERK and p38 MAPK signaling axes, demonstrating etiological specificity distinct from canonical cAMP pathway inhibition. Full article

Polyvinyl alcohol/carboxymethyl cellulose (PVA/CMC) blend nanocomposites reinforced with plasma-assisted synthesized zinc oxide–gold (ZnO–Au) nanoparticles were prepared via casting at varying nanoparticle concentrations. Structural and interfacial modifications were analyzed using XRD, FTIR, Raman spectroscopy, and XPS. XRD analysis confirmed the nanocomposite crystallinity, showing an average crystallite size of 24.48 nm and a lattice strain of 4.32 × 10⁻³ for the 0.15 wt% ZnO–Au composite. FTIR and Raman spectra revealed band shifts and broadening, indicating strong interactions between ZnO–AuNPs and the polymer matrix. XPS analysis further verified Zn and Au incorporation and changes in C 1s and O 1s intensities, reflecting modified surface chemistry. Optical analysis revealed a reduction in the band gap from 4.60 eV (pure PVA/CMC) to 3.52 eV for the 0.15 wt% ZnO–Au nanocomposite, accompanied by an increase in refractive index from 2.058 to 2.244, along with enhanced UV-shielding the performance due to reduced UV transmittance and increased film opacity. Thermogravimetric analysis demonstrated enhanced thermal stability, while antibacterial tests against E. coli and S. aureus confirmed strong antimicrobial activity. These findings demonstrate that PVA/CMC/ZnO–Au nanocomposites are a promising candidate for antibacterial, UV-blocking, food packaging, and optoelectronic applications. Full article

Cisplatin’s chemotherapy is hindered by drug resistance and toxicity, making copper complexes a potential alternative. A novel copper(II) complex, [CuLBr], was synthesized from a tetradentate vicinal dioxime ligand (H₂L) and characterized. [CuLBr] features a distorted square pyramidal geometry with a CuN₄Br chromophore. DFT calculations showed a narrowed HOMO-LUMO gap and increased electrophilicity, enhancing its chemical reactivity. [CuLBr] exhibited potent biomimetic catalytic activity, functioning as an efficient superoxide dismutase mimic and catalase mimic. Biophysical studies (UV-Vis, fluorescence, and viscosity) demonstrated a strong, spontaneous affinity of [CuLBr] for calf thymus DNA and Human Serum Albumin, suggesting groove-binding and static quenching mechanisms. In vitro assays revealed superior anticancer activity against HepG-2, HCT-116, and MDA-MB-231 cell lines, with greater selectivity than the free ligand and doxorubicin. Molecular docking studies reveal a high binding affinity of [CuLBr] with key proteins, including ferredoxin-1 and VEGF. This may suggest potential dual mechanisms of action, involving the induction of cuproptosis and the inhibition of tumor angiogenesis. These findings position [CuLBr] as an effective multi-metal-based anticancer agent with advantageous selectivity. Full article

Chemical coagulation is a highly important step of the conventional treatment processes, determination of the optimum coagulant dose to meet the demand of particulate materials and natural organic matters (NOMs) in raw water is crucial for good drinking water quality. WTC-Coag is a universal non-site-specific coagulant prediction model using three raw water quality parameters, UV₂₅₄, colour, and turbidity, as model inputs. The empirical model can determine the dose for maximum dissolved organic carbon (DOC) removal to achieve the conditions of enhanced coagulation; it also features an operator-selectable input—% setpoint (as % DOC removal)—to establish a dose for the desirable treated water quality. This hybrid modelling and control approach in practice is extremely useful for operators to be able to optimise the process by balancing between water quality and use of resources (chemical and sludge disposal costs) for sustainable operation. This paper discusses the practicality of this hybrid modelling approach via a long-term evaluation by comparing the plant dose against predicted dose using five years historical operations and water quality data. The assessment covered raw water quality change against treatment performance, predictability, usability and operator behaviour in response to the dose change situation. During the study period, five “black water” events were captured, and the performance of the predictability due to operational changes and operator’s response in these extreme events have been analysed. The comparison between the predicted enhanced dose and the plant dose indicated enhanced coagulation would not be always required. Furthermore, the selection of 50% setpoint from the targeted dose option matched well with the plant dose during which the lower-dose situation would be sufficient, with 90% of the predicted doses within ±10 mg/L of the plant dose and 95% of the predicted doses within ±15 mg/L of the plant dose during the normal period. The use of a correction factor to compensate for the particulate demand due to powdered activated carbon (PAC) dose during “black water” events has shown to be effective. The 50% setpoint matches with the plant alum dose over the entire period after accounting for the PAC dose, with 70% of the predicted doses within ±10 mg/L and 80% within ±15 mg/L of the plant dose. All the coagulation-related prediction functions have been evaluated and confirmed their non-site-specific nature. This study is unique in terms of using real operations data for an extended period to evaluate this novel hybrid modelling concept towards the sustainability goal. Full article

Electrospinning and electrospraying nanotechnologies were used to valorise agro-industrial residues into biohybrid controlled-release polyphenol (CRP) scaffolds. Four polyhydroxybutyrate ± polycaprolactone (PHB±PCL) architectures were fabricated that differed in polymer phase, Klason lignin from hazelnut shell (HS-KL) presence vs. absence, and co-location with grape-pomace polyphenols (GP-PPs), as well as in distribution between fibres and bead-like depots. Scaffolds were characterised using optical microscopy/stereomicroscopy/SEM, FTIR, UV–Vis spectroscopy, and dynamic water contact angle (absorption). GP-PP release was monitored for 14 days at ~25 °C and 37 °C, the latter representing shallow-soil hot-spell conditions in Mediterranean zones. All matrices exhibited multimodal release, with modest initial bursts and three phases (burst, mid, and late tail), analogous to controlled-release fertiliser profiles. At ~25 °C, the PHB/PCL matrix with HS-KL confined to PHB fibres and GP-PP in large PCL beads showed the highest total GP-PP release, whereas the architecture with HS-KL and GP-PP co-located in both PHB and PCL fibres and in PCL depots combined high total release with a smoother, well-metered late phase. At 37 °C, this HS-KL-GP-PP co-located scaffold was the most robust, retaining the highest total and late tail release. These results identify HS-KL-GP-PP co-located PHB/PCL architectures as promising carriers for temperature-resilient delivery of bioactive polyphenols in Mediterranean agrosystems. Full article

While many [FeFe]-hydrogenase biomimetics are effective proton-reduction catalysts, few are active for H₂ oxidation, and examples containing both a pendant amine group, able to act as a proton relay, and a second redox center, both essential features of the enzymes, are rare. Here we report the preparation and oxidation chemistry of two ferrocene-functionalized amino-diphosphines (PCNCP), (CH₂PR₂)₂NCH₂Fc (R = Ph (1), Cy (2)), and their ethylenedithiolate (edt) diiron complexes, [Fe₂(CO)₄(μ-edt){κ²-(R₂PCH₂)₂NCH₂Fc}] (R = Ph (3), Cy (4)). Their crystallographic characterization shows that PCNCP occupies an apical–basal position. CV responses are slightly R-dependent, showing for 3 and 4 in three separate oxidative processes assigned to successive one-electron oxidation of the diiron core (quasireversible), appended Fc (reversible), and the amine–diiron moiety (irreversible), as confirmed by IR and UV–Vis spectroelectrochemical studies supported by Density Functional Theory (DFT) and Time-dependent Density Functional Theory (TDDFT) calculations. The first oxidation results in a structural rearrangement of the Fe(PNP)(CO) unit and the formation of a semi-bridging carbonyl. Slow protonation of 3 with HBF₄∙Et₂O affords the corresponding N-protonated cation in acetone, whilst μ-hydride products dominate for both 3 and 4 in CD₂Cl₂. A preliminary H₂ oxidation study was carried out with 3, and while there was some evidence of activity, it was much lower than reported for alkyl-functionalized PCNPC diiron derivatives. Full article

Antisense oligonucleotides (ASOs) are nucleic acid therapeutics that regulate gene expression through sequence-specific hybridization with target RNA. Under physiological conditions, many target RNAs adopt higher-order structures, which can strongly influence ASO accessibility and binding behavior. Although UV melting analysis is widely used to evaluate the thermal stability of ASO/RNA duplexes, this approach does not adequately account for the structural features of target RNAs. In this study, we investigated the utility of surface plasmon resonance (SPR) analysis as an in vitro method to evaluate ASO binding while considering RNA structural constraints. Multiple ASOs were designed to target PRF84, an 84-nucleotide RNA motif that induces −1 programmed ribosomal frameshifting in HIV-1 gag-pol expression. SPR analyses were performed to compare ASO interactions with complementary RNA fragments and with structurally folded PRF84. The results demonstrated that identical ASOs exhibited distinct binding behaviors depending on whether the target was a complementary RNA or PRF84, indicating that RNA structure significantly affects ASO binding. These findings suggest that SPR analysis enables the evaluation of ASO–RNA interactions taking structure into account, and may be a useful alternative approach to conventional UV melting analysis-based ASO screening. Full article