Search Results (11,996)

Background: Eleutherococcus senticosus (Rupr. et Maxim.) Maxim., widely used in Russian and Chinese traditional medicine for its anti-inflammatory activity, contains bioactive compounds capable of stabilizing epithelial function and reducing inflammation. Despite prior research on its effects in the colon, the impact and mechanism of action of E. senticosus fruit extract on epithelial tissues of the upper digestive and respiratory tract remains unexplored. Objectives: This study aimed to evaluate the influence of E. senticosus fruit extract on the transepithelial electrical potential and resistance in the tracheal and small intestinal epithelium of rabbits. In addition, the chemical composition of the extract was also profiled by the means of UHPLC-DAD-MS. Methods: Tissue segments from the trachea and small intestine of New Zealand white male rabbits were examined using the Ussing chamber technique. Three concentrations of E. senticosus fruit extract (0.001, 0.1, 10 mg/100 mL) were applied, and changes in transepithelial electrical potential (dPD) and resistance (R) were recorded. Chemical analysis of the extract was conducted using UHPLC-DAD-MS. Results: For the first time, we have discovered that the E. senticosus extract increased membrane resistance in tracheal tissue, suggesting enhanced barrier integrity. In contrast, a slight decrease in resistance was observed in small intestinal tissue. UHPLC-DAD-MS confirmed the presence of chlorogenic acid, dicaffeoylquinic acids, quercetin derivatives, and myo-inositol, compounds known for their antioxidant, anti-inflammatory, and membrane-stabilizing effects. Conclusions: The differential response of respiratory and intestinal epithelium to the E. senticosus extract highlights its tissue-specific action and supports its traditional use in the prevention and treatment of diseases characterized by epithelial barrier dysfunction, such as asthma, COPD, and Crohn’s disease. Full article

Photodynamic therapy (PDT) has evolved considerably over the past decades, progressing from first-generation porphyrins to second- and third-generation photosensitizers, including nanocarrier-based systems with improved selectivity and bioavailability. In parallel, matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) has become a gold standard for the characterisation of complex biomolecules, enabling precise determination of molecular mass, purity and stability. This narrative review explores the intersection of these two fields, focusing on how MALDI-TOF MS supports the development, characterisation and clinical application of photosensitizers used in PDT. Literature searches were performed across PubMed, Web of Science, Scopus and Base-search, followed by targeted retrieval of studies on MALDI and PDT applications. Findings indicate that MALDI-TOF MS plays a crucial role at multiple stages: confirming the synthesis and chemical integrity of novel photosensitizers, monitoring their metabolic stability in biological systems and characterising photodegradation products after PDT. Moreover, MALDI imaging mass spectrometry (MALDI-IMS) enables spatial mapping of photosensitizer distribution in tissues, while rapid pathogen identification by MALDI-TOF supports antimicrobial PDT applications. Collectively, the evidence highlights that MALDI-MS is not only a tool for molecular characterisation but also a versatile analytical platform with a direct translational impact on PDT. Its integration with other omics and multimodal imaging approaches is expected to enhance the personalization and clinical effectiveness of photodynamic therapy. Full article

The synthesis of silver nanoparticles (AgNPs) using sustainable and non-toxic methods has become an important research focus due to the limitations of conventional chemical approaches, which often involve hazardous reagents and produce unstable products. In particular, the effects of reaction conditions on the quality and stability of AgNPs obtained via green synthesis remain insufficiently understood. This study addresses this gap by examining the influence of pH and temperature on the synthesis of AgNPs using Rosmarinus officinalis extract as both reducing and stabilizing agents. UV-vis spectroscopy and TEM analysis revealed that optimal conditions for producing uniform, stable, and spherical AgNPs were achieved at pH 8, with a narrow size distribution (~17.5 nm). At extreme pH values (≤3 or ≥13), nanoparticle formation was hindered by aggregation or precipitation, while elevated temperatures mainly accelerated reaction without altering particle morphology. HRTEM and SAED confirmed the crystalline face-centered cubic structure, and colloids synthesized at pH 8 showed excellent stability over 30 days. Overall, the results demonstrate that precise pH control is critical for obtaining high-quality AgNPs via a simple, scalable, and environmentally friendly approach. Their stability and homogeneous size highlight potential applications in biomedicine, food packaging, and sensing, where reproducibility and long-term functionality are essential. Full article

Chitin, one of the most abundant natural polysaccharides, has gained increasing attention for its structural diversity and potential in biomedicine, agriculture, food packaging, and advanced materials. Conventional chitin production from crustacean shell waste faces limitations, including seasonal availability, allergenic protein contamination, heavy metal residues, and environmentally harmful demineralization processes. Chitin from fungi and microalgae provides a sustainable and chemically versatile alternative. Fungal chitin, generally present in the α-polymorph, is embedded in a chitin–glucan–protein matrix that ensures high crystallinity, mechanical stability, and compatibility for biomedical applications. Microalgal β-chitin, particularly from diatoms, is secreted as high-aspect-ratio microrods and nanofibrils with parallel chain packing, providing enhanced reactivity and structural integrity that are highly attractive for functional materials. Recent progress in green extraction technologies, including enzymatic treatments, ionic liquids, and deep eutectic solvents, enables the recovery of chitin with reduced environmental burden while preserving its native morphology. By integrating sustainable sources with environmentally friendly processing methods, fungal and microalgal chitin offer unique structural polymorphs and tunable properties, positioning them as a promising alternative to crustacean-derived chitin. Full article

CO₂ hydrogenation to methanol has attracted considerable attention as a promising catalytic route for both reducing CO₂ emissions and producing valuable chemical intermediates. Among various catalysts, Cu–ZnO-based systems are the most widely studied; however, their performance remains constrained by limited methanol selectivity and stability, highlighting the need for improved catalytic strategies. In this work, liquid metal gallium (Ga) was incorporated into Cu–ZnO catalysts as an additive for CO₂ hydrogenation to methanol. Owing to its high dispersibility and fluidity, Ga helps maintain long-term catalyst stability. We investigated different introduction methods for Ga promoters and found that the physical mixing approach generated the strongest alkaline sites, thereby enhancing CO₂ activation and increasing the CO₂ conversion to methanol. Moreover, this catalyst effectively suppressed carbon deposition, further improving its stability. These findings offer new insights into the use of liquid metal Ga in CO₂ hydrogenation and provide fresh perspectives for the rational design of efficient methanol synthesis catalysts. Full article

The deposition of asphaltenes poses a critical challenge to the petroleum industry, reducing the efficiency of oil wells and, in severe cases, clogging pipelines. Dispersants are widely used to enhance asphaltene stability, but asphaltenes are complex, solubility-defined compounds with variable properties, leading to uncertainties in dispersant microscopic mechanisms, macroscopic effects, and their relationships—requiring further study. This work investigated two anionic dispersants (sodium dodecyl benzene sulfonate (SDBS) and dodecyl benzene sulfonic acid (DBSA)) for dispersing GT asphaltene (GT-ASP, isolated from offshore heavy oil), aiming to improve offshore heavy oil stability. Using an asphaltene–toluene system, it analyzed dispersant effects on GT-ASP stability, particle size, and adsorption and underlying mechanisms. DBSA showed superior performance: at 1000 ppm (w/v), it reduced GT-ASP average particle size from ~160 nm to ~29 nm and increased the onset of the flocculation point (OFP) from 33.5 vol% to 63.0 vol%, driven by chemical adsorption, hydrogen bonding, and π–π conjugation. In contrast, SDBS promoted aggregation: particle size reached 257 nm (1000 ppm (w/v)) and 1271 nm (5000 ppm (w/v)), with OFP at 54.6 vol%, likely due to Na⁺-induced charge neutralization, insufficient steric hindrance, and “micellar bridges” via SDBS self-aggregation. Finally, this study makes a valuable contribution to both the theoretical guidance and the practical application of asphaltene dispersants. Full article

Background: This study aimed to evaluate the impact of different chemical treatments on titanium implant surfaces and their biological compatibility. Methods: Titanium dental implants were immersed in Ringer’s solution, hydrogen peroxide (3%), citric acid (40%), EDTA (40%), or a citric–phosphoric acid mixture. Electrochemical behavior was analyzed using open-circuit potential monitoring and electrochemical impedance spectroscopy over 168 h. Cytocompatibility was assessed by culturing human gingival mesenchymal stem cells (MSCs) directly on treated implants and in conditioned media, followed by viability evaluation through CCK-8 assays. Results: Citric acid and Ringer’s solution preserved passive film stability and supported high MSC viability (>75%) with minimal cytotoxic effects. Hydrogen peroxide and the citric–phosphoric acid mixture caused pronounced surface corrosion, decreased impedance stability, and significantly reduced cell viability (57–65%). EDTA-treated surfaces showed intermediate results, with moderate viability but impaired cell adhesion. Conclusion: The findings highlight the dual influence of chemical decontamination on implant stability and biological response. Citric acid and Ringer’s solution appear to be safer protocols for surface decontamination, whereas hydrogen peroxide and mixed acid treatments should be applied with caution due to their detrimental electrochemical and cytotoxic effects. Full article

Microplastics (<5 mm) and nanoplastics (~100 nm), which are invisible to the naked eye, originate primarily from fragmentation and breakdown larger plastic debris are increasingly pervasive in the environment. Once released, they can disperse widely in the environment, pollute them adversely and ultimately be taken up by living organisms, including humans, through multiple exposure pathways. Their distribution in aquatic systems is influenced by their physiochemical properties including density, hydrophobicity, and chemical stability, along with environmental conditions and biological activities. To better understand the dynamics of micro- and nanoplastics in surface water, this study conducted a comprehensive review of 194 published articles and scientific reports covering marine, freshwater, and wastewater systems. We assessed the abundance, spatial distribution and the factors that govern their behavior in aquatic systems and analyzed the sampling techniques, pretreatment process, and detection and removal techniques to understand the ongoing scenario of these pollutants in surface water and to identify the ecological risks and potential toxicological effects on living biota via direct and indirect exposure pathways. Full article

Potassium–selenium (K-Se) batteries have emerged as a promising energy storage system in view of their high theoretical energy density and low cost. However, their practical application is restricted due to challenges such as polyselenide shuttling, low redox activity, and significant cathode volume expansion during cycling, leading to inferior Coulombic efficiency and a short cycling lifespan. Carbon-based materials, with their superior electronic conductivity, adjustable pore structures, and robust chemical stability, have been extensively studied and employed as cathode materials in K-Se batteries, demonstrating remarkable potential in addressing the above-mentioned issues. Considering the rapidly growing research interest in this topic in recent years, herein, we comprehensively summarize recent advances in the application of carbon-based materials as cathodes in K-Se batteries. First, we introduce the properties, key challenges, and optimization strategies of K-Se batteries, including encapsulating Se within carbon materials, engineering chemisorptive hosts, and electrocatalyzing redox reactions. Furthermore, we discuss the relationship between fabrication strategies, micro/nanostructures, and electrochemical performances. Finally, we propose future prospects for the rational design and application of carbon-based cathodes in K-Se batteries and other alkaline metal–chalcogen batteries. Full article

SPCEs are crucial for electrochemical sensing because of their portability, low cost, disposability, and ease of mass production. This study details their manufacture, surface modifications, electrochemical characterization, and use in chemical and biosensing. SPCEs integrate working, reference, and counter electrodes on PVC or polyester substrates for compact sensor design. Surface modifications, such as plasma treatment (O₂, Ar), nanomaterial addition (AuNPs, GO, CNTs), polymer coatings, and MIPs, enhance performance. These changes improve sensitivity, selectivity, stability, and electron transport. Electrochemical methods such as CV, DPV, SWV, and EIS detect analytes, including biomolecules (glucose, dopamine, and pathogens) and heavy metals (Pb²⁺, As³⁺). Their applications include healthcare diagnostics, environmental monitoring, and food safety. Modified SPCEs enable rapid on-site analysis and offer strong potential to transform our understanding of the physical world. Full article

Nickel oxide (NiO), a wide bandgap p-type semiconductor, has emerged as a promising material for electrochemical sensing owing to its excellent redox properties, chemical stability, and facile synthesis. Its strong electrocatalytic activity enables effective detection of diverse analytes, including glucose, hydrogen peroxide, environmental pollutants, and biomolecules. Advances in nanotechnology have enabled the development of NiO-based nanostructures such as nanoparticles, nanowires, and nanoflakes, which offer enhanced surface area and improved electron transfer. Integration with conductive materials like graphene, carbon nanotubes, and metal–organic frameworks (MOFs) further enhance sensor performance through synergistic effects. Innovations in synthesis techniques, including hydrothermal, sol–gel, and green approaches, have expanded the applicability of NiO in next-generation sensing platforms. This review summarizes recent progress in the structural engineering, composite formation, and electrochemical mechanisms of NiO-based materials for advanced electrochemical sensing applications. Full article

In this study, the chemical solubility (stability) of yttria-partially stabilized zirconia (2.3Y-TZP) dental ceramics, both glazed (Group 2) and non-glazed samples (Group 1), was evaluated using a modified testing protocol based on ISO 6872:2024. Chemical stability was assessed by measuring ion release with inductively coupled plasma mass spectrometry (ICP-MS) and by analyzing phase composition with X-ray diffraction (XRD). While ISO 6872 prescribes chemical stability testing in a 4 wt.% aqueous acetic acid solution at 80 °C for 16 h, the exposure duration in this study was extended to 768 h (32 days) to allow a more accurate determination of long-term solubility behavior. Additionally, the surface roughness parameters (R_a, R_max, R_z, S_a, S_q) were analyzed and evaluated before and after solubility testing. Kinetic analysis revealed that degradation followed a near-parabolic rate law, with power-law exponents of n = 2.261 for Group 1 and n = 1.935 for Group 2. The corresponding dissolution rate constants were 3.85 × 10⁻⁵ µgⁿ·cm⁻²ⁿ·h⁻¹ for Group 1 and 132.3 µgⁿ·cm⁻²ⁿ·h⁻¹ for Group 2. XRD results indicated that the long exposure to acetic acid induced a partial phase transformation of zirconia from the tetragonal to the monoclinic phase. Under prolonged acetic exposure, the glaze layer on 2.3Y-TZP exhibited significantly higher dissolution, whereas the zirconia (polished, unglazed) showed low ion release. The temporal change in the total amount of dissolved ions was statistically analyzed for Group 1 and Group 2. The samples showed a strong correlation, but ANOVA confirmed significant differences between them. Full article

TiO₂ is the most used material for the photocatalytic removal of organic pollutants in aqueous media. TiO₂, specifically its anatase phase, is well-known for its great performance under UV irradiation, high chemical stability, low cost and non-toxicity. Nevertheless, TiO₂ presents two main drawbacks: its limited absorption of the visible spectrum; and its relatively low specific surface area and pore volume. Regarding the latter, several works in the literature have addressed the issue by developing new synthesis approaches in which anatase is dispersed and supported on the surface of porous materials. In the present work, two series of materials have been prepared where anatase has been supported on mesoporous silica (MSTiR%) in situ through a hydrothermal synthesis approach, where, in addition to using tetraethoxysilane (TEOS) as a silicon precursor, three organotriethoxysilanes [RTEOS, where R = methyl (M), propyl (P) or phenyl (Ph)] were used at a RTEOS:TEOS molar percentage of 10 and 30%. The materials were thoroughly characterized by several techniques to determine their morphological, textural, chemical, and UV-vis light absorption properties and then the most promising materials were used as photocatalysts in the photodegradation of the emerging contaminant and antiepileptic carbamazepine (CBZ) under UV irradiation. The materials synthesized using 10% molar percentage of RTEOS (MSTiR10) were able to almost completely degrade (~95%), 1 mg L⁻¹ of CBZ after 1 h of irradiation using a 275 nm LED and 0.5 g L⁻¹ of catalyst dose. Therefore, this new synthesis approach has proven useful to develop photoactive TiO₂ composites with enhanced textural properties. Full article

A rapid targeted screening method for 22 compounds, including flavonoids, glycosides, and phenolics, in Dendrobium officinale was developed using UHPLC–MS/MS, demonstrating good linear correlation coefficients, precision, repeatability, and stability. D. officinale from the Guangnan and Maguan regions can be effectively classified into two distinct categories using PCA. In addition, OPLS-DA discriminant analysis enables clear separation between groups, with samples forming well-defined clusters. The 22 chemical components provide valuable origin-related information for D. officinale. The compounds with VIP values of >1 included eriodictyol, vanillic acid, protocatechuic acid, gentisic acid, and naringenin. The difference in naringenin content between D. officinale from the two production areas was minimal. By contrast, eriodictyol and vanillic acid were relatively abundant in D. officinale from Guangnan, while gentisic acid and protocatechuic acid were more prevalent in D. officinale from Maguan. The pathways with higher Kyoto Encyclopedia of Genes and Genomes enrichment were primarily associated with lipid metabolism and atherosclerosis, fluid shear stress and atherosclerosis, and nonalcoholic fatty liver disease. These findings suggest that D. officinale exhibits promising lipid-balancing properties and potential cardiovascular health benefits. Seven machine learning algorithms—Random Forest, XGBoost, Support Vector Machine, k-Nearest Neighbor, Backpropagation Neural Network, Random Tree, and CatBoost—demonstrated superior accuracy and precision in distinguishing D. officinale from the Guangnan and Maguan regions. The key compounds with higher weights—vanillic acid, chrysoeriol, trigonelline, isoquercitrin, gallic acid, 4-hydroxybenzaldehyde, eriodictyol, sweroside, apigenin, and homoeriodictyol—play a crucial role in model construction and the identification of D. officinale from the Guangnan and Maguan regions. The quantification of 22 compounds using UHPLC–MS/MS, combined with PCA, OPLS-DA, and machine learning, enables effective discrimination of D. officinale from these two Yunnan production areas. Full article

Fucoidan B (FucB) is a sulfated polysaccharide with recognized biological activity. In this study, FucB was chemically modified through redox conjugation with gallic acid (GA) to obtain FucB-GA, aiming to enhance its antioxidant properties. Structural characterization using FTIR, NMR, and electrophoresis confirmed the successful covalent binding of GA to FucB without major structural degradation. The conjugation increased the phenolic content and reduced crystallinity, as shown by XRD and SEM, indicating greater amorphous character, which can favor biological applications. Thermogravimetric analysis demonstrated enhanced thermal stability in FucB-GA. Antioxidant activity was evaluated through various in vitro assays. FucB-GA showed superoxide radical scavenging activity of 91.96%, copper chelating capacity of 43.2%, antioxidant capacity of 37 mg AEE/g, and reducing power of 94.22%, significantly higher results than FucB, while no sample chelated iron. Under the conditions analyzed, gallic acid alone showed minimal or no activity in most assays. These results suggest that conjugation with GA increases the antioxidant potential of FucB, while also improving the activity and bioavailability of GA, likely due to the increase in electron-donating and metal-binding groups. Overall, the study supports the development of FucB-GA as a promising antioxidant compound for pharmaceutical or nutraceutical applications. Full article