Search Results (776)

To improve the visible-light-driven photocatalytic degradation efficiency of g-C₃N₄-based photocatalysts toward organic pollutants, a MoS₂/g-C₃N₄ composite precursor was employed in this work, and the phase composition and defect environment of Mo species were regulated by post-annealing under air and N₂ atmospheres, respectively, thereby constructing Mo-based/g-C₃N₄ (MCN) composites with distinct structural evolution characteristics. The results showed that the photocatalytic activity of the as-sonicated MCN composite toward methylene blue (MB) was only moderately improved, among which the 15% loading sample exhibited the best performance with a degradation efficiency of about 42.0% within 60 min. In contrast, annealing at 400 °C under N₂ resulted in only a slight activity change, whereas the sample treated at 400 °C in air (Air-15% MCN) achieved an MB degradation efficiency of 99.9% within 60 min, together with a much higher pseudo-first-order reaction rate constant than that of the air-treated sample at a lower temperature. XRD, FT-IR and XPS analyses revealed that air annealing induced the conversion of MoS₂ into highly crystalline MoO₃ (or MoO₃₋_x), leading to the formation of a reconstructed MoO₃₋_x/g-C₃N₄ composite interface. Meanwhile, the increased high-binding-energy component in the O 1s spectrum and the EPR signal around g ≈ 2.00 further suggested the presence of more abundant defect-related centers in the air-treated sample. Although Air-15% MCN possessed a lower specific surface area than the untreated and N₂-treated samples, it displayed enhanced visible-light absorption, higher transient photocurrent response, lower interfacial charge-transfer resistance, and accelerated carrier dynamics, indicating that the activity enhancement mainly originated from atmosphere-induced phase transformation, interfacial reconstruction, defect-related active centers, and improved charge separation/transfer, rather than from the surface area effect. Based on the above results, a possible interfacial charge-transfer pathway is tentatively proposed for the g-C₃N₄/MoO₃₋_x interface formed after air treatment, which contributes to the efficient utilization of photogenerated carriers and the rapid degradation of MB. This work demonstrates that atmosphere-induced phase transformation is a simple and effective strategy for regulating the structure and photocatalytic performance of Mo-based/g-C₃N₄ composites, and provides useful guidance for the design of efficient visible-light photocatalysts. Full article

Endoplasmic reticulum (ER) stress and the unfolded protein response (UPR) represent fundamental cellular adaptive mechanisms that maintain protein homeostasis and metabolic balance. Many RNA viruses, particularly flaviviruses such as dengue virus (DENV), Zika virus (ZIKV), West Nile virus (WNV), yellow fever virus (YFV), and Japanese encephalitis virus (JEV), extensively remodel the ER to establish replication compartments and assemble progeny virions. This massive reorganization disrupts ER homeostasis, leading to UPR activation. Emerging evidence reveals that flaviviruses not only trigger but also manipulate the three UPR branches—PERK, IRE1, and ATF6—to optimize viral translation, replication, and egress. In parallel, flavivirus infection profoundly alters host lipid metabolism and promotes dynamic changes in lipid droplets (LDs), key organelles that mediate lipid storage and serve as scaffolds for viral replication and assembly. The UPR intimately connects to LD biogenesis through transcriptional and translational programs mediated by XBP1, ATF4, and ATF6, thereby coupling ER stress responses to lipid remodeling and energy homeostasis. This intricate crosstalk between UPR and LDs creates a metabolic and structural niche favorable for viral replication but detrimental to host cell integrity. This review provides a comprehensive analysis of the molecular mechanisms by which flaviviruses exploit ER stress and the UPR to reprogram lipid metabolism and LD dynamics. We highlight the dual role of UPR signaling in promoting adaptive lipid synthesis and initiating cell death under prolonged stress, discuss recent insights into ER–LD interactions during flavivirus infection, and explore therapeutic opportunities targeting UPR–lipid metabolic pathways as broad-spectrum antiviral strategies. Understanding this interconnected network will advance our knowledge of viral pathogenesis and identify new avenues for host-directed antiviral intervention. Full article

Licania tomentosa leaf extract was used to synthesize zinc oxide nanoparticles (ZnO NPs) which were systematically analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-Visible (UV-Vis) and Fourier transform infrared (FT-IR) spectroscopies and energy-dispersion X-ray spectroscopy (EDS) methods. Based on XRD scans, the green NPs have an average crystallite size of 15.9 nm as estimated using the Scherrer equation and have a roughly spherical shape with an average diameter of 25.15 ± 1.2 nm as calculated from SEM data. As estimated from the Tauc plot based on UV-Vis absorption spectra, ZnO NPs have a small band gap of 3.0 eV. The biosynthesized ZnO NPs were effectively utilized for the photodegradation of methylene blue (MB) and crystal violet (CV) dyes under UV illumination with resulting MB and CV degradation efficiencies of ~94% and ~81% after 60 min and 70 min, with pH = 12 and pH = 10, respectively. Different experimental parameters such as NPs quantity, experimental pH, light intensity and initial concentration of dyes were varied to test the performance of the catalyst. Furthermore, efficient recycling of the catalyst was demonstrated. We also undertook antimicrobial studies of the green ZnO NPs. The ZnO NPs demonstrated broad-spectrum antimicrobial efficacy against Escherichia coli ATCC 35218, Enterococcus faecalis ATCC 29737, Klebsiella pneumoniae ATCC 700603, Pseudomonas aeruginosa ATCC 27853, P. aeruginosa B3, Staphylococcus aureus ATCC 29213, and S. aureus SA01, with the minimum inhibitory concentration (MIC) and the inhibitory concentrations associated with 50% effect (IC50) values ranging from 250 to 2000 µg/mL and 7.74 to 283.14 µg/mL, respectively. The nanoparticles also significantly inhibited biofilm formation by E. faecalis ATCC 29737, P. aeruginosa ATCC 27856, and S. aureus SA03. The antimicrobial efficiency of the ZnO NPs against Escherichia coli ATCC 25922 and Staphylococcus aureus SA03 isolates was also assessed using the disk diffusion assays. Taken together, our results reveal that the biosynthesized ZnO NPs are promising multifunctional materials with potential applications in antimicrobial treatments, biofilm control, and photocatalytic remediation. Full article

Fluoroquinolone antibiotics, like danofloxacin, are considered as crucial veterinary drugs due to their high antibacterial potential, a broad spectrum of activity and good pharmacological properties. However, owing to the widespread use of this group of pharmaceuticals, microbial resistance to them is becoming a serious worldwide concern. In the present study, novel silver and copper complexes of danofloxacin were prepared and characterized using ¹H NMR, ¹⁹F NMR and IR spectroscopy, ESI-MS spectrometry, and elemental analysis. The antimicrobial properties of the obtained complexes were determined against selected bacterial and fungal strains, including yeast and conidia-forming fungi. Additionally, toxicities of danofloxacin metal-based complex solutions were assessed toward eukaryotic cells. The obtained results indicate that silver(I) and copper(II) complexes of danofloxacin exhibit good antimicrobial activity against bacteria that are important from the veterinary point of view, like Listeria monocytogenes or Campylobacter jejuni, in concentrations which are not cytotoxic. The MBC values of metal-based danofloxacin complexes for the mentioned strains were 1.5 times lower than those obtained for danofloxacin. Additionally, the solution of the novel silver–danofloxacin complex was found to have a fungicidal effect against the studied Candida and Aspergillus strains. Full article

Green synthesis is an eco-friendly, simple, and cost-effective process for the synthesis of metal nanoparticles from plant extracts that are rich in bioactive compounds. In the current study, the antioxidant potential and total soluble polyphenol content (TPC) of different parts of Ligusticum mutellina (L.) Crantz were evaluated using DPPH (2,2-diphenyl-1-picrylhydrazyl) and FRAP (ferric reducing antioxidant power) assays, and the results indicated that the seed extract was the most active plant part. HPLC analysis indicated the presence of phenolic compounds such as gallic acid, protocatechuic acid, and catechin, which may contribute to the reduction and stabilization of AgNPs. Silver nanoparticles (AgNPs) were synthesized from the aqueous seed extract of L. mutellina. The formation of nanoparticles was confirmed by UV–Vis spectroscopy, FT-IR analysis, powder X-ray diffraction (PXRD), and transmission electron microscopy (TEM). The UV–Vis spectrum indicated a surface plasmon resonance peak at around 411 nm, and PXRD analysis indicated an average crystallite size of around 13 nm. TEM analysis revealed predominantly spherical nanoparticles with an average size of 25.36 ± 10.76 nm. The synthesized AgNPs exhibited strong antibacterial activity against Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria. Overall, the results demonstrate that L. mutellina seed extract represents an effective natural source of reducing and stabilizing agents for green nanoparticle synthesis and highlight the potential of the obtained AgNPs as environmentally friendly antimicrobial materials. Full article

It is found that the speckle structure of the photoinduced light scattering indicatrix of the LiNbO₃:Y³⁺(0.46 wt%) crystal and its behavior with the time of crystal irradiation with a laser undergo an atypical behavior caused by the features of the dissipation processes of laser-induced defects in the crystal. In the frequency range of 100–4000 cm⁻¹, the Raman spectra of the LiNbO₃:Y³⁺(0.46 wt%) single crystal were recorded upon excitation by visible (532 nm) and near-IR (785 nm) laser radiation. Five second-order Raman scattering lines were detected in the frequency range of 1000–2100 cm⁻¹, with the frequencies of two of them (of about 1790 cm⁻¹ and 1940 cm⁻¹) somewhat exceeding the doubled value of the frequencies of fundamental vibrations of the 4A₁(z)LO (longitudinal optical) and 9E(x,y) symmetry types, which allows us to attribute these lines to the overtones of the fundamental vibrations of 4A₁(z)LO and 9E(x,y). It is found that only one Raman scattering line is observed in the region of stretching vibrations of OH-groups (3200–3800 cm⁻¹). The frequency of this line is found to depend on the scattering geometry, varied within 3431–3438 cm⁻¹, and to be shifted to the low-frequency region by about 30–50 cm⁻¹ relative to the frequencies in the IR absorption spectrum. This finding may be due to the alternative prohibition rule due to the presence of the center of symmetry of the oxygen octahedra O₆ of the crystal structure. Full article

Background and Objectives: Human data on obesity and type 2 diabetes mellitus (T2DM) remain limited and inconsistent, particularly with respect to adiposity-related phenotypes and renal involvement. We aimed to assess PNX-14 across body mass index (BMI) categories and to investigate its associations with BMI, insulin resistance indicators, and proteinuria in adults with T2DM. Materials and Methods: In this prospective cross-sectional study, participants were classified into four groups according to World Health Organization body mass index (BMI) thresholds: 18.5–24.9, 25.0–29.9, 30.0–34.9, and ≥35.0 kg/m². Serum PNX-14 was measured using a human ELISA kit. Group comparisons, trend analysis, false discovery rate-adjusted Spearman correlations, HC3-robust multivariable regression, and parsimonious structural equation modeling were performed. Results: PNX-14 differed significantly across BMI categories and increased monotonically with increasing BMI (p < 0.001 for both the overall comparison and the trend). PNX-14 showed a positive correlation with BMI (ρ = 0.491; qFDR < 0.001), whereas no significant relationship was observed with insulin or HOMA-IR after FDR correction (qFDR = 0.795 for insulin and qFDR = 0.793 for HOMA-IR). In the model adjusted for age, sex, and BMI, higher PNX-14 was independently associated with lower proteinuria (β = −0.326, 95% CI −0.584 to −0.067; p < 0.05), whereas BMI was positively associated with proteinuria (β = 0.407, 95% CI 0.132 to 0.682; p < 0.01). Structural equation modeling supported positive BMI→PNX-14 and BMI → proteinuria paths, a negative PNX-14→proteinuria path, and a non-significant PNX-14→HOMA-IR path. Conclusions: In adults with T2DM, PNX-14 appears to be more consistently related to adiposity than to glycemic or insulin resistance indicators. However, when evaluated together with proteinuria, it may offer a testable framework for phenotyping based on renal involvement within the obesity spectrum. Nevertheless, this approach needs to be validated in studies from different centers and with repeated measurements. Full article

In order to find green fungicides derived from natural products, 22 unreported anethole-based thiazolinone-hydrazone compounds were designed and synthesized, and their structures were characterized by FT-IR, ¹H NMR, ¹³C NMR, and HRMS. At a concentration of 50 mg/L, the preliminary antifungal activity of the target compounds against eight plant pathogens was evaluated. The results showed that 5q (R = m-OH C₆H₄) exhibited the best inhibitory activity against most of the tested plant pathogenic fungi, demonstrating that this compound had certain broad-spectrum antifungal activity. In addition, a reasonable and effective 3D-QSAR model (r² = 0.994, q² = 0.529) was established using the comparative molecular field analysis (CoMFA) method to study the relationship between the structures of the target compounds and their antifungal activity against Physalospora piricola. Meanwhile, the results of electrostatic potential calculation of the compounds indicated that the electronic effect caused by different substituents on the benzene ring might be one of the factors affecting antifungal activity. In addition, frontier molecular orbital calculations implied that the anethole moiety and the thiazolinone-hydrazone-benzene structure in the target compounds might play an important role in antifungal activity. The potential binding mode between the target compound 5q (R = m-OH C₆H₄) and the homology-modeled succinic dehydrogenase was explored by molecular docking. Full article

Thermoplastic starch (TPS) can be a sustainable alternative to petrochemical plastics for flexible packaging, especially in rainforests and tropical regions where native starch sources such as cassava are abundant. However, one problem preventing TPS packaging from widespread use is its susceptibility to moisture. This study evaluated TPS formulations based on Amazonian cassava starch reinforced with plantain leaf fibers, beeswax, and low-density polyethylene (LDPE) particles. The plastic compounds were extruded to obtain pellets and then films at 120–130 °C. The resulting films were then cut and heat-sealed to obtain flexible packaging. Different properties of the TPS packages were evaluated, such as mechanical strength, water vapor transmission (WVTR), color, infrared spectrum (FT-IR), and moisture adsorption. The results showed that the formulation with beeswax (2% w/w), plantain leaves powder (1% w/w), and LDPE powder (2% w/w) had a higher tensile strength (5.99 MPa) and moisture barrier (WVTR = 366.6 g m⁻² d⁻¹) compared to the control formulation only with plasticizers (glycerol and water) but without reinforcements (0.48 MPa and 1486.6 g m⁻² d⁻¹, respectively). Films with only beeswax (4% w/w) and plantain leaves powder (2.5% w/w) had tensile strength = 5.53 MPa and WVTR = 716.8 g m⁻² d⁻¹, with higher moisture adsorption compared to the samples with LDPE. In both cases, homogeneous and heat-sealable bags were obtained. The reinforced TPS films can be used to reduce the environmental impact generated by single-use packaging applications such as food commercialization. Full article

Post-harvest deterioration in strawberries is an urgent and critical issue that requires significant attention. Glycerol monolaurate (GML), a broad-spectrum food-grade antimicrobial agent, faces limited applicability due to its poor water solubility. In this study, a confined encapsulation strategy was employed to encapsulate GML within hydroxypropyl-γ-cyclodextrin (HPγCD), which improved the physicochemical properties of GML and enhanced its stability in the environment. The fiber morphology was observed through scanning electron microscopy (SEM) and transmission electron microscopy (TEM), confirming the presence of a uniform, non-nodular core–shell structure. The Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) validated the successful encapsulation of GML within the cavity of HPγCD. Thermogravimetric analysis (TGA) demonstrated that the thermal stability of the core–shell system was significantly improved. In vitro release followed first-order kinetics (R² = 0.9842), with 79.5% of GML released over 68 h. The DPPH and ABTS assays demonstrated that PLA/GML-HPγCD NF exhibited sustained radical scavenging activity (p < 0.05, ANOVA). Compared to GML-HPγCD NF, PLA/GML-HPγCD NF exhibited prolonged antibacterial activity against Escherichia coli and superior antifungal efficacy in strawberry preservation. Meanwhile, PLA/GML-HPγCD NF significantly reduced lesion diameter and weight loss while maintaining hardness, total soluble solids, and vitamin C content over 8 days of storage. In conclusion, these characteristics highlighted the potential of P/G-HPγCD NF as a promising active packaging material for extending the shelf life of perishable fruits. Full article

The clinical efficacy of chemotherapy against rapidly proliferating cells stimulates both the development of new agents and the reassessment of established drugs. Spectroscopic methods (UV, FT-IR, and ¹H NMR) were applied to characterize prospidium chloride and related substances. The FT-IR spectrum of prospidium chloride, arising from vibrational transitions within the alkyl fragments of the dispirotripiperazinium cation, is reported with band assignments. Electronic transitions between molecular orbitals are analyzed using quantum–mechanical selection rules (Laporte and spin selection rules). The n→σ* transition (ΔS = 0) corresponds to the absorption maximum at λmax = 282 ± 0.40 nm (ε = 3.89 ± 0.08 L·mol⁻¹·cm⁻¹). A ¹H NMR spectrum (700 MHz) was used to assign chemical shifts δ (ppm), J-coupling constants (Hz), and gauche conformational features of prospidium chloride and its dihydroxy and epoxy impurities. Quantitative ¹H NMR (qNMR) was applied to determine the content of the active pharmaceutical ingredient and related substances. The methods provide complementary structural information for the characterization of prospidium chloride. Full article

This paper investigates the different relaxation channels of a single symmetric top NH₃ and a spherical top CH₄ molecule trapped at low temperature in a clathrate hydrate nano-cage in the infrared absorption domain of their vibrational degrees of freedom. The approach utilizes the Born–Oppenheimer approximation and the extended site inclusion model applied to CO₂ in a previous work, which was based on pairwise atom–atom effective interaction potentials. The calculations show that trapping the methane or ammonia molecule is energetically more favorable in a type sI clathrate structure than in an sII one, and entropic considerations show that methane can be released much more easily than ammonia from clathrate hydrate nano-cages. In the small (s) and large (l) nano-cages with the sI structure, the CH₄ molecule exhibits a more or less perturbed rotational motion, while the NH₃ molecule shows a strongly hindered orientational motion that tends to a three-dimension librational motion (oscillation motion) around its orientational equilibrium configuration. The calculated orientational energy level schemes are quite different from those of the molecular free rotation. In the static field inside the cage, degenerate ${\nu }_3$ and ${\nu }_4$ vibrational modes of methane and ammonia molecules are shifted and split. Moreover, for ammonia molecules, the ${\nu }_1$ and ${\nu }_2$ modes are shifted, and the inversion motion is no longer allowed. The non-radiative and radiative relaxation channels of CH₄, NH₃ and CO₂ in clathrate nano-cages are discussed with reference to the matrix isolation spectroscopic results. Upon laser excitation, then, from the energy levels calculated for the different degrees of freedom, NH₃ and CO₂ are expected to fluoresce, while for CH₄, non-radiative relaxation should lead to evaporation at the surface of clathrates. Experimental setups are suggested to localize and study these species underneath ice surfaces on distant planets or planetesimals from mobile detectors such as drones or CubeSats equipped with appropriate laser sources and telescopes with 2D imaging detectors. Full article

Existing super-resolution evaluation systems for fluorescence microscopy images struggle to effectively detect potential artifacts in weak signal reconstruction. This study aims to establish a multi-dimensional evaluation framework that integrates frequency-domain evidence to verify the reliability of super-resolution techniques under low signal-to-noise ratio (SNR) conditions. All ground-truth (HR) images used in this study are experimentally acquired fluorescence microscopy data; the corresponding low-quality inputs are simulated from HR via controlled degradations (e.g., bicubic downsampling and frequency-truncation-based degradation) to enable paired quantitative evaluation. We designed a hierarchical comparative experiment to systematically evaluate the performance differences of CNN (SRCNN/FSRCNN), GAN (Real-ESRGAN), and Transformer (SwinIR) architectures on nucleus and whole-cell structure datasets. This study reveals a significant decoupling between “visual sharpness” and “signal fidelity”: while Real-ESRGAN can generate highly impactful high-frequency textures, its checkerboard effect in the spectrum and random residuals in the error map expose serious “illusion” risks, making it unsuitable for precise quantitative analysis. All ground-truth (HR) images used in this study are experimentally acquired fluorescence microscopy data; the corresponding low-quality inputs are simulated from HR via controlled degradations (e.g., bicubic downsampling and frequency-truncation-based degradation) to enable paired quantitative evaluation. Full article

Infectious pathogens pose serious threats to public health, necessitating the development of more antimicrobials. In this study, oligohydroxybutyrates were obtained through the catalyzed polymerization of β-butyrolactone using N, N-dimethyl-4-aminopyridine (DMAP) and aluminum isopropoxide [Al(OiPr)₃] and applied as sustainable antimicrobial agents. The poly3-hydroxybutyrate (PHB) oligomers exhibited broad-spectrum antibacterial activities against both Gram-negative (E. coli) and Gram-positive (S. aureus) model bacteria. Additionally, PHB oligomers displayed robust (inhibiting rate: >95%) and rapid (action time: <20 min) antiviral activity against three notorious single-stranded RNA viruses, that is, influenza A virus (H1N1 and H3N2) and coronavirus (SARS-CoV-2). In particular, a comprehensive set of advanced experimental characterizations, including FT-IR, ¹H- and ¹³C-NMR, and H-ESI-MS/MS, was applied to analyze their chemical structures. The results confirmed the loss of terminal hydroxyl groups in the PHB intermediate and end products associated with theoretical calculations. These findings will also help provide deep insight into the major chain growth mechanism during the synthesis of PHB. The structural variations, which were treated as unwanted side reactions, were identified as a pivotal factor by deactivating the terminal hydroxy during chain growth. Their effective sterilization properties and degradability endowed the as-prepared PHB oligomers with a promising biomedical potential, including for use as disinfectants, sanitizers, and antiseptics. Full article

Mosquito-borne diseases, including dengue fever, chikungunya, and Zika, continue to pose a substantial global public health challenge. This is largely attributable to the absence of effective vaccines and the expanding distribution of vectors such as Aedes albopictus (Ae. albopictus). Repellents, therefore, remain a critical component of prevention strategies for disease prevention. However, existing formulations have notable limitations. Synthetic repellents such as DEET provide broad-spectrum efficacy but may raise safety concerns, especially at high concentrations. In contrast, botanical repellents, such as citronella and camphor oils, offer more favorable safety profiles but are restricted by short protection durations due to their high volatility. To overcome these drawbacks, this research developed a composite mosquito repellent through the strategic combination of DEET (5–15%), citronella oil (10–20%), and camphor oil (5–15%). This formulation leverages interactions across multiple olfactory pathways to simultaneously enhance efficacy and reduce the DEET concentration. Orthogonal experimental optimization identified an optimized formulation, Mix-3 (consisting of 15% DEET, 15% citronella oil, and 10% camphor oil in 75% ethanol), which achieved a mean complete protection time of 9.45 h. Mix-3 provided longer protection than 7% DEET (mean difference = 5.50 h, p < 0.001), 4.5% IR3535 (2.83 h, p < 0.001), 10% citronella oil (3.58 h, p < 0.001), and 15% DEET (6.50 h, p < 0.001). Catnip oil did not contribute significantly to repellency (p = 0.895). This study demonstrates that the rational combination of synthetic and botanical repellents effectively overcomes the limitations of single-agent formulations, providing a long-lasting and scalable approach for vector control. Full article