Search Results (1,417)

Remote sensing reflectance (R_rs) in optically complex waters is controlled by the combined effects of phytoplankton, colored dissolved organic matter (CDOM), and suspended mineral particles. In the Baltic Sea, strong CDOM absorption and variable particle loads complicate the interpretation of ocean color signals and the retrieval of biogeochemical properties. In this study, we investigate the individual and combined influence of these optically significant constituents on R_rs using a set of HydroLight radiative transfer simulations representing typical Baltic Sea conditions. A wide range of chlorophyll-a (0.25–10 mg·m⁻³), CDOM absorption (0.5–15 m⁻¹), and particulate inorganic matter (0.04–4 g·m⁻³) was considered. To quantify the influence of each component, a spectral response function was applied, defined as the change in R_rs relative to a normalized perturbation of each input parameter. This approach preserves information about the magnitude of the reflectance signal and allows direct comparison of the impact of different constituents across the visible spectrum. The spectral response analysis reveals that the relative influence of each constituent varies with wavelength and environmental conditions, highlighting the limitations of single-band or ratio-based algorithms in optically complex waters. These findings provide a quantitative framework for interpreting spectral variability of R_rs in the Baltic Sea and other optically complex water basins, support the development of more robust bio-optical algorithms for Case 2 waters. Similar spectral response analysis can be conducted in other water basins in order to quantify combined constituent-specific effects on R_rs. Full article

Utilizing seawater samples collected during the summer of 2025 in the Dingzi Bay region, South Yellow Sea, this study conducted a comprehensive analysis of the contents and concentrations of dissolved gases (N₂, O₂, Ar, CO₂) and hydrocarbon gases (such as methane, ethane, and propane). The findings reveal that the dissolved gases in the study area are predominantly composed of N₂ and O₂, with average proportions of 77.8% and 21.6%, respectively. Notably, significant CO₂ anomalies were detected at certain stations, which may indicate intense organic matter degradation or the introduction of external fluids. Furthermore, wet gas constituents, including propane, butane, and isobutane, were identified in several samples, suggesting potential submarine oil and gas seepage or subsurface thermogenic gas input. Spatial analysis revealed that anomalous points were primarily concentrated at stations CJ01, CJ08, CJ10, and CQ01, with no significant correlation to water depth, suggesting that their distribution may be influenced by local geological structures or bottom currents. This study elucidates the complexity and heterogeneity of dissolved gas composition in the waters of Dingzi Bay, thereby providing a novel scientific foundation for regional carbon cycle research, seabed resource exploration, and marine environmental monitoring. Full article

The aqueous seed extract of Ammodaucus leucotrichus Cosson & Durieu (AL-AE), a Saharan annual herb of the family Apiaceae, was evaluated for the first time as a green corrosion inhibitor for mild steel in 1.0 M hydrochloric acid. GC-MS analysis after acetylation derivatization identified ten constituents representing 99.22% of the total detected area, with 17-pentatriacontene (47.69%), 2,4-di-tert-butylphenol (13.24%), and myo-inositol (8.62%) as the dominant species. Inhibition performance was assessed by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) over 25–100 ppm at 298–328 K. At 100 ppm and 298 K, AL-AE achieved 96.17% by EIS and 97.10% by PDP. Adsorption obeyed the Langmuir model with a standard free energy of adsorption of −38.2 kJ mol⁻¹, consistent with a mixed physisorption–chemisorption mechanism. SEM/EDS confirmed protective film formation, with surface oxygen dropping from 34.9 to 4.1 wt%. Density functional theory (DFT) calculations at the B97-3c/CPCM (water) level in ORCA 6.1 identified 2,4-di-tert-butylphenol as the most reactive constituent, while Fukui index analysis based on Mulliken population analysis located the preferential adsorption sites on each molecule. Full article

Per- and polyfluoroalkyl substances (PFASs) are persistent environmental contaminants whose mobility in soil and groundwater is strongly controlled by adsorption and desorption processes. In saturated clay-rich soils, these processes are complex because PFASs interact with hydrated mineral surfaces, organic matter, metal oxides, exchangeable cations, and pore-water constituents. This review synthesizes the current literature on PFAS adsorption and desorption in saturated soils, with an emphasis on clay mineralogy, mineral–water interfaces, pore-water chemistry, and electrochemical double layer (EDL) effects. PFAS retention is influenced by molecular properties such as chain length, functional head group, and charge state, as well as soil properties such as organic carbon content, clay mineral type, surface charge, cation exchange capacity, and Fe/Al oxide content. Longer-chain PFASs and sulfonate-based compounds generally show stronger retention, while shorter-chain PFASs tend to remain more mobile. This review focuses particularly on how an EDL affects PFAS behavior in saturated clay systems. Unlike dry clay surfaces, saturated clay surfaces are covered by structured water, exchangeable ions, and diffuse counterion layers. These hydrated interfacial conditions influence how closely anionic PFASs can approach negatively charged clay surfaces, how dissolved cations reduce electrostatic repulsion or promote cation-mediated binding, and how effectively short-range interactions such as hydrophobic association, van der Waals forces, hydrogen bonding, and surface association contribute to adsorption. Desorption is also emphasized because adsorption does not necessarily represent permanent immobilization. Changes in pH, ionic strength, cation composition, dissolved organic matter, or competing solutes can weaken retention and promote PFAS release. Overall, PFAS mobility in saturated clay-rich soils should be interpreted as a coupled interfacial process rather than simple partitioning to soil solids. Future work should better connect molecular-scale mechanisms, EDL behavior, adsorption–desorption experiments, and saturated transport studies to improve predictions of PFAS retention and long-term groundwater release. Full article

Characterizing the human health risk posed by constituents in drinking water is often challenging due to a lack of published toxicity values. The PIANO (Paraffin, Isoparaffin, Aromatic, Naphthene, and Olefin) analytical method measures nearly 300 compounds in JP-5 jet fuel, 43 of which have published oral reference doses (RfDs). The remaining compounds are typically assigned surrogate toxicity values. We predict RfDs for 290 PIANO compounds using Quantitative Structure–Activity Relationship (QSAR) models based on stepwise linear regression of 2-dimensional molecular descriptors (MDs) and published toxicity values. Five training groups, created by randomly selecting 80% of the non-PIANO compounds and 50% of the 43 PIANO compounds that have RfDs within a master dataset of 1113 compounds, were used to develop five QSAR models. We used the geometric means of four QSAR model results of sufficient quality to predict RfDs for compounds lacking toxicological information. For compounds with known RfDs, 884 (79%) were within 8-fold of published RfDs, well within the acknowledged uncertainty inherent in published RfDs. Our approach has applicability beyond PIANO compounds and represents a new alternative methodology (NAM) that may be used to reduce uncertainty in human health risk assessment and guide regulatory decisions. Full article

4-Chlorophenoxyacetic acid (4-CPA), a synthetic auxin analog, is employed in agriculture both as a plant growth regulator and as a constituent of herbicide formulations. Consequently, the establishment of simple and rapid detection methods is essential for effective environmental monitoring. This study reports the first development of a homogeneous fluorescence polarization immunoassay (FPIA) for the determination of 4-CPA. The monoclonal antibody (M1), raised against 4-CPA, was evaluated as a recognition element. Furthermore, two fluorescently labeled 4-CPA tracers—with ethylenediamine fluorescein thiocarbamate and aminohexylaminocarbonylfluorescein—were synthesized and purified, and their structures were unequivocally confirmed by high-performance liquid chromatography coupled with high-resolution mass spectrometric detection (HPLC-HRMS). Optimal concentrations of monoclonal antibodies and tracers were established, yielding a limit of detection of 1.2 ng/mL. The assay demonstrated a broad dynamic range of 2.3–300 ng/mL and a rapid analysis time of 15 min. Validation via the standard addition method in authentic open water samples resulted in recovery rates of 98–112%. To address the cross-reactivity with the prevalent herbicide 2,4-dichlorophenoxyacetic acid (2,4-D), two novel strategies were devised and successfully implemented. The first approach involves the concurrent execution of two separate FPIAs—one for 2,4-D and one for 4-CPA—followed by the mathematical resolution of two analyte concentrations from the two measured binding values. The second strategy entails the preliminary selective removal of 2,4-D from sample matrices using affinity chromatography columns with immobilized anti-2,4-D antibodies prior to FPIA for 4-CPA. These proposed methodologies appear highly promising for overcoming the inherent limitations of traditional immunoassays when faced with significant cross-reactivity among structurally analogous compounds. Full article

The rational design of mixed micellar systems has emerged as a cornerstone of modern nanomedicine, offering unprecedented control over the solubility and bioavailability of challenging therapeutic agents. This review provides a comprehensive analysis of the physicochemical principles governing the assembly of amphiphilic drugs and surfactants into synergistic nanostructures. By articulating the transition from traditional guest/host solubilization to “drug-as-component” models, we highlight the critical role of molecular interactions in achieving therapeutic precision. It further outlines the experimental methodologies used to investigate these systems and elucidates how they enhance the solubility, stability, and bioavailability of poorly water-soluble drugs. Special emphasis is placed on the practical applications of synergy in reducing systemic toxicity and optimizing drug release kinetics, providing a roadmap for the development of next-generation nano-pharmaceuticals. The functionality of these systems is significantly influenced by the molecular interactions among their constituents; thus, quantitative analysis of these interactions might enhance the formulation of more effective pharmaceuticals. This review outlines the key physicochemical principles of mixed micelle formation, including thermodynamics and synergistic interactions of amphiphiles, while emphasizing their relevance in current research and practical pharmaceutical applications. Various experimental methods, such as surface tension measurement, conductometric and calorimetric tests, and spectroscopic techniques, are compared in terms of their conditions of application and performance in understanding micelle formation and micelle structure. We clearly point out that the interpretation and evaluation of the properties of colloidal systems containing drug molecules solubilized by mixed micelles and an amphiphilic drug incorporated into micelles must be discussed and evaluated separately. Understanding the limitations and characteristics of the physical/chemical principles applied is essential for the rational design of mixed micelle carriers tailored to specific therapeutic needs. Full article

Tung cake, a by-product of Vernicia fordii oil extraction, is an underutilized biomass residue rich in natural bioactive constituents and therefore shows potential for the development of sustainable protective formulations. In this study, tung cake-derived systems, including the aqueous extract, fermentation broth, and extract–ethanol mixtures with different ethanol volume fractions, were prepared and systematically evaluated as a unified protective system on two representative biological surfaces, namely rubberwood and fresh fruit. For rubberwood, the formulations were assessed in terms of uptake behavior, antifungal efficacy against Aspergillus niger, resistance to moisture swelling, and physicochemical characteristics using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Scanning Electron Microscopy (SEM). For fruit surfaces, preservation performance was evaluated through weight loss, decay rate, and color retention during storage. The results showed that formulation performance depended strongly on the preparation route and extract–ethanol mixture. In rubberwood, the 60–90% mixtures and the extract displayed showed better performance antifungal activity, with the 60%, 80%, and 90% mixtures reaching a control efficacy of 75.00% and the extract achieving 68.75%. The treatments also improved the dimensional stability of wood, and the water-saturated volumetric swelling rate decreased from 8.98% in the control to 5.63% in the extract-treated group. FTIR and XRD analyses indicated that the basic lignocellulosic chemical framework and cellulose-related diffraction features of rubberwood were largely retained after treatment, while treatment-dependent qualitative spectral and apparent diffraction differences were observed. SEM provided more direct evidence of surface-associated covering and reduced fungal attachment. A comparable protective tendency was also observed on fruit surfaces. In oranges, the 80% extract–ethanol mixture showed the most favorable preservation performance under the tested storage conditions, maintaining a decay rate of 0 throughout 10 days of storage, reducing weight loss to 17.76%, and preserving surface color more effectively than the control. Overall, the 80% ethanol mixture achieved the best balance between antimicrobial activity and barrier-related protection across both rubberwood and fruit surfaces. These findings demonstrate that tung cake waste can be converted into a bio-based protective system with potential mold-inhibiting and preservation functions across different biological substrates. Full article

Herpes simplex virus type 1 (HSV-1) remains a significant pathogen, particularly in immunocompromised patients. The emergence of drug-resistant strains necessitates alternative therapeutic agents. Lentinula edodes (LE), Hypsizygus marmoreus, and Pleurotus eryngii are edible mushrooms with recognized medicinal properties. However, their effects on drug-resistant HSV-1 remain unclear. This study characterized metabolites from high-temperature/high-pressure (121 °C) water extracts of fresh and dried fruiting bodies and evaluated anti-HSV-1 activities using in vitro and in silico approaches. Metabolic profiles were analyzed by electrospray ionization–quadrupole time-of-flight mass spectrometry. Antiviral activity against HSV-1 KOS (wild-type) and HSV-1 dxpiii (drug-resistant) strains was assessed by plaque assays and qPCR. Molecular docking and network pharmacology were performed on candidate compounds. LE extract from dried mushroom tended to show the highest levels of selected major bioactive constituents, along with greater antioxidant activities. All extracts significantly inhibited viral infection and gene expression in both strains. LE extract from dried mushroom modulated the expression of NFKB1 and IL6. Molecular docking analysis revealed that eritanidine showed a predicted binding affinity to HSV-1 DNA polymerase (−7.95 kcal/mol). Additionally, eritanidine, 5′-methylthioadenosine, and 3-indoleacrylic acid were predicted to interact with TNF and MAPK1. Several compounds also demonstrated favorable drug-likeness properties. Overall, these mushroom extracts are promising natural sources of antiviral agents against HSV-1, including drug-resistant variants. Full article

Gao-shan-hong-jing-tian (GSHJT) Oral Liquid is a phytochemical-rich preparation derived from Rhodiola, yet its anti-hypoxic active constituents and molecular mechanisms remain poorly understood. This study aimed to identify the key anti-hypoxic phytochemicals in GSHJT Oral Liquid and clarify their mechanisms of action to support its potential use in managing acute mountain sickness (AMS). We first established and validated an HPLC method for quality control, then comprehensively profiled the chemical composition using LC-MS. Network pharmacology and molecular docking were applied to predict the core anti-hypoxic components, candidate targets and signaling pathways. The primary bioactivity was further verified through an in vitro carbonic anhydrase (CA) inhibition assay. A total of 71 constituents were identified, with kaempferol and ellagic acid emerging as the primary anti-hypoxic phytochemicals. These compounds target seven core proteins (SRC, PIK3R1, ESR1, EGFR, PTK2, IGF1R, and LYN) to regulate vascular tone, inflammation, oxidative stress, blood–brain barrier integrity, and cell survival under hypoxic conditions. By modulating pathways such as HIF-1α, PI3K/AKT, FAK/PTK2, SRC, and IGF1R, these phytochemicals ultimately influence the onset and alleviation of AMS. Enzyme inhibition assays demonstrated that kaempferol and ellagic acid inhibited CA with IC₅₀ values of 34.05 μM and 119.1 μM, respectively. Molecular docking further revealed that both compounds suppressed CA activity through a combination of hydrogen bonding and hydrophobic interactions, consistent with a zinc-bound water-anchoring mechanism. This study elucidates the phytochemical basis and molecular mechanism responsible for the anti-hypoxic effects of GSHJT Oral Liquid, providing scientific support for its potential application as a natural, plant-derived intervention for preventing and alleviating acute mountain sickness, providing scientific support for its potential application and offering a reproducible paradigm for the rational development of other Rhodiola-based phytomedicines, though further in vivo validation is required to confirm the anti-hypoxic efficacy. Full article

This study investigates tide–surge nonlinear interactions along the southeastern coast of China (SCC) using Typhoon Winnie as a case study. A coupled tide–surge model is established based on the Finite-Volume Community Ocean Model (FVCOM), incorporating realistic bathymetry, tidal constituents, wind fields, and atmospheric pressure. The results show that tide–surge interactions contribute up to 1.8 m to the total water level, with the most pronounced effects occurring in shallow, high-friction coastal regions such as Hangzhou Bay, the Yangtze River Estuary, and the Jiangsu coast. Sensitivity experiments reveal that the quadratic bottom friction term is the dominant mechanism driving the nonlinear interaction, while the advection term plays a secondary role. The interaction intensity is highly sensitive to water depth and topographic slope; reducing water depth generally intensifies the interaction, though the response is non-monotonic in regions with complex bathymetry such as the radial sand ridge field. The phase and period of astronomical tides also exert significant control. Notably, semi-diurnal constituents (e.g., M₂, S₂) dominate the interaction, accounting for up to 80% of the nonlinear effect, whereas diurnal constituents contribute negligibly (less than 0.1 m). Tide–surge coupling significantly affects both the magnitude and timing of extreme water levels, with enhanced interaction occurring during astronomical low tide at some stations (e.g., Dinghai). These findings underscore the necessity of incorporating tide–surge interactions, particularly with accurate bottom friction and semi-diurnal tidal forcing, into storm surge models for improved forecasting and disaster risk assessment along China’s southeastern coast. Full article

Gold-mine tailings have attracted increasing interest as alternative constituents in cement-based materials, yet their use in structural concrete remains limited by the lack of multivariable approaches capable of capturing the interaction between tailing fractions with different functional roles. In this study, a tailing-derived fine aggregate and a fine tailing sludge from the Cisneros Project (Santo Domingo, Antioquia, Colombia) were jointly incorporated into structural concrete and evaluated through a response surface methodology based on a central composite design. The tailings were characterized by physical, chemical, mineralogical, and morphological analyses, while concrete mixtures proportioned according to ACI 211 were assessed in terms of 28-day compressive strength. The statistical model revealed a significant quadratic response and a strong interaction between both incorporation variables. The most favorable strength region, based solely on 28-day compressive strength, was identified at sludge contents below 20% and tailing aggregate replacement below 90%, with the latter interpreted as a preliminary mechanical threshold rather than as a practical recommendation for field application. Higher incorporation levels led to strength losses associated with the increasing fineness of the system and greater water demand. This study demonstrates that the performance of tailing-modified structural concrete depends on the coordinated dosage of fractions with distinct roles and provides preliminary mechanical incorporation limits based solely on 28-day compressive strength. Since durability and environmental safety tests, including heavy metal/cyanide leaching, permeability, shrinkage, and chemical resistance, were not conducted, these limits should not be interpreted as definitive recommendations for long-term structural application. Full article

The global transition to a diversified renewable energy portfolio requires reliable assessment of predictable marine energy resources. This study develops a high-resolution, three-dimensional Regional Ocean Modeling System (ROMS) to quantitatively evaluate theoretical tidal current energy resources in the Bohai and Yellow Seas. The model, configured with fine-scale bathymetry and forced by harmonic tidal constituents, is validated against tide gauge and Acoustic Doppler Current Profiler (ADCP) observations. Multi-year simulations reveal pronounced spatial heterogeneity in tidal current energy distribution. Rather than treating resource assessment as a single power density mapping exercise, this study combines annual mean theoretical power density, peak theoretical power density, threshold-dependent effective flow duration, effective water depth, current directionality, and vertical velocity structure to characterize resource intensity, temporal persistence, and vertical deployability. The results identify distinct hydrodynamic resource regimes. High theoretical resource intensity is concentrated west of Laotieshan Cape and east of Chengshantou, where cumulative annual effective flow duration exceeds 5000 h and short-term instantaneous theoretical power density can reach approximately 10 kW/m² and 8 kW/m², respectively. These peak values indicate strong local tidal acceleration but should be interpreted together with annual mean power density and effective flow duration. In contrast, the northern Jiangsu coastal area exhibits lower peak intensity but relatively persistent moderate flow conditions. The results provide a hydrodynamic resource basis for preliminary site screening and for guiding subsequent turbine-performance, wake/array, environmental, grid accessibility, and techno-economic assessments. Full article

Bacopa monnieri (BM) is a traditional medicinal herb that has been reported to have neuroprotective and cognitive-enhancing properties. In this study, the antioxidant, safety, and neuroprotective properties of BM extract (BME) were assessed in a lipopolysaccharide (LPS) model of cognitive impairment. Ethanol was used for extraction, after which the ethanolic extract was profiled to characterize total phenolic and flavonoid content and major bioactive constituents. The assessment of antioxidant activity was done through several in vitro tests (DPPH, ABTS, FRAP, NBT, OARC, and metal chelation). Toxicity was assessed in Caenorhabditis elegans using pharyngeal pumping and food clearance tests. For in vivo evaluation, rats were pre-treated with BME, and then LPS was administered, followed by evaluation of cognitive performance by the Morris water maze and Y-maze test. Phytochemical examination revealed the existence of phenolics and flavonoids, as well as bacoside A components. The extract showed good antioxidant activity, mainly via hydrogen atom transfer and single-electron transfer, suggesting effective radical scavenging and reducing ability, but no metal chelating activity was observed. Toxicity tests demonstrated that lower concentrations of the extract were well tolerated, and higher concentrations resulted in temporary inhibition of feeding behavior, indicating mild, dose-dependent effects. In the LPS-induced rat model, the inflammatory challenge produced significant cognitive deficits relative to normal controls, validating the model. Pre-treatment with BME at 70 mg/kg did not produce statistically significant rescue of any behavioral endpoint compared with the LPS-only group, although small-to-medium effect sizes in the protective direction were observed for several measures. Additionally, BME modulated LPS-induced neuroinflammatory responses by reducing cortical IL-1β, TNF-α, iNOS, and COX-2 levels while enhancing hippocampal AChE and PGE2 activity, suggesting region-specific anti-inflammatory and cholinergic regulatory effects. The most robust positive findings of this study are therefore the phytochemical characterization and the in vitro antioxidant profile of this standardized extract, which support its potential as a candidate for further investigation in inflammation-related cognitive impairment; the in vivo findings are preliminary and warrant confirmation in larger-scale, dose-ranging studies. Full article

Background: Nanophyton iliense U.P. Pratov is a Central Asian halophytic plant whose phytochemical composition and suitability for pharmaceutical formulation remain insufficiently explored. This study evaluated the chemical profile, antioxidant activity, preliminary safety, and gel-forming potential of a hydroethanolic extract of N. iliense for topical application. Methods: The extract was characterized by GC–MS and HPLC. Total polyphenol content was determined, antioxidant activity was assessed using FRAP and DPPH assays, and preliminary cytotoxicity was evaluated using the Artemia salina lethality assay. Results: GC–MS and HPLC analyses showed that the extract contained both lipophilic constituents, including terpenoid and phytosterol-related compounds, and phenolic compounds such as catechin, epicatechin, and naringin. The total polyphenol content reached 485.05 mg GAE/L, exceeding the values obtained for the other plant extracts analyzed under the same conditions. The extract showed concentration-dependent antioxidant activity in both FRAP and DPPH assays. In the DPPH assay, radical scavenging activity increased up to 90.06% at 1.0 mg/mL, while FRAP results confirmed a strong reducing capacity. In the Artemia salina assay, no cytotoxic effect was observed at the tested concentrations. To assess pharmaceutical applicability, five gel formulations were prepared and compared. Gel No. 4, containing N. iliense extract, Lecigel, glycerin, Tween 80, benzyl alcohol, and purified water, showed the most suitable organoleptic and technological characteristics, including homogeneity, good spreadability, and absence of greasy residue. Conclusions: The obtained results indicate that N. iliense extract can be incorporated into a semi-solid formulation, while the extract itself demonstrates relevant in vitro antioxidant properties. Full article