Search Results (97)

This study aims to characterize the seasonal variability and optical properties of aerosols and to investigate their potential sources, transport pathways, and radiative impacts over a rural site in Southeast India. Ground–based MICROTOPS–II Sunphotometer observations during April 2021–December 2023 were integrated with trajectory–based source analysis and OPAC–SBDART radiative–transfer simulations to examine the links between aerosol characteristics, meteorological conditions, source regions, and radiative effects. The annual mean aerosol optical depth at 500 nm (AOD₅₀₀) was found to be 0.56 ± 0.22, peaking during pre–monsoon (0.66 ± 0.19) and winter (0.64 ± 0.23), and lowering during the rainy monsoon (0.49 ± 0.21). Enhanced aerosol loading during the dry seasons was associated with local emissions and long–range continental transport, whereas monsoon conditions favored marine influence, atmospheric ventilation and wet scavenging, as supported by trajectory analyses using potential source contribution function (PSCF) and concentration weighted trajectory (CWT) models. Higher Ångström exponent (AE) values during winter and pre–monsoon (1.30 ± 0.24) indicated dominance of fine–mode continental aerosols, while the lower monsoon values (0.83 ± 0.37) reflected increased contribution of coarse particles. Negative values of spectral curvature further confirmed fine–mode dominance during dry seasons. The estimated precipitable water vapor increased markedly from winter (2.00 ± 0.37 cm) to monsoon (4.35 ± 0.35 cm), likely influencing aerosol optical properties through hygroscopic growth. Meteorological parameters significantly modulated aerosol loading and size distribution across seasons. AOD–AE relationships revealed predominance of fine anthropogenic aerosols in all seasons except monsoon, while aerosol classification indicated substantial fine–mode contributions under turbid atmospheric conditions. OPAC–SBDART simulations estimated significant aerosol–induced surface cooling (−41 to −42 W m⁻²) and atmospheric warming (38–41 W m⁻²) under high aerosol loading conditions, leading to atmospheric heating rates of 1.1–1.2 K day⁻¹. However, lower aerosol loading in monsoon reduced heating rates to 0.3–0.4 K day⁻¹. Current findings highlight the critical role of monsoon flow and meteorological dynamics in regulating aerosol characteristics and regional radiative forcing over Southeast India. Full article

Biochar-supported rare earth oxides are herein assessed as heterogeneous catalysts for the UV-assisted Catalytic Wet Peroxide Oxidation (UV-CWPO) treatment of pharmaceuticals under mild conditions. Catalysts were synthesized by two different pyrolysis methods (activated carbon-assisted oxygen-limited pyrolysis in a muffle furnace, and inert-gas pyrolysis in a tubular furnace under nitrogen flow), and characterized by XRD, SEM, and N₂ adsorption–desorption isotherms. Their performance in assisting 385 nm UVA-LED CWPO treatment of acetaminophen (ACE), diclofenac (DCF), and metamizole (MTZ) was assessed under circumneutral pH conditions. The biochar-supported cerium-loaded catalyst prepared by oxygen-limited pyrolysis reported the highest activity, achieving 80% ACE and 70% DCF removals within 120 min of treatment, whereas MTZ was completely removed in less than 10 min, with only 16% of the removal attributable to adsorption. Superoxide radicals dominated the degradation mechanism, and photogenerated holes and hydroxyl radicals contributed moderately. Catalyst stability (minimal activity loss and negligible cerium leaching) was confirmed over five consecutive reuses. Degradation efficiency decreased ≈12–18% because of radical scavenging losses caused by the content of inorganic ions and organic matter in tap, river, and WWTP effluent waters. Treated effluents addressed lower toxicity than untreated solutions, reinforcing the environmental safety of this treatment strategy. Full article

Earth’s early history provides the only natural record for evaluating how planetary evolution can generate environments capable of initiating life. Here we review early Earth evolution through the lens of urability: the time-dependent capacity of planetary environments to support prebiotic chemistry progressing toward compartmentalized, self-propagating, information-bearing systems. We argue that urability is not a single globally habitable state, but a transient overlap among several coupled dimensions: liquid water availability, permissive temperature, ocean pH and salinity, access to bioessential elements, atmospheric shielding and volatile retention, and exposed or shallow environments that enable concentration, mineral catalysis, and wet–dry cycling. During the Hadean–early Archean transition, these dimensions were shaped by magma-ocean degassing, late accretion history, atmospheric compositional evolution from CO₂-rich to more N₂-dominated states, ferruginous ocean chemistry, tectonic recycling, continental growth, and intermittent land emergence. These processes created tradeoffs: high pCO₂ may have enhanced abiotic nitrogen fixation but imposed hot and acidic conditions, whereas CO₂ drawdown improved climate and ocean pH while weakening some fixed-nitrogen sources; ferruginous chemistry could locally enhance phosphate availability while also promoting nutrient scavenging; and tectonic recycling could stabilize the carbon cycle while generating chemically diverse but spatially intermittent land environments. We therefore frame life’s origin as a planetary timing problem, in which prebiotic opportunities opened and closed as multiple environmental constraints came into and out of overlap. This perspective motivates coupled models that resolve when and where water, temperature, pH, nutrients, energy, atmospheric photochemistry, and exposed land surfaces jointly produced urable environments on Earth and other rocky planets. Full article

Hydrogel bio-adhesives have gained great attention in wound healing and tissue regeneration applications because conventional wound closures are often hindered by insufficient adhesion and poor biocompatibility. Considering that dynamic covalent interactions facilitate robust wet adhesion in hydrogels, we fabricated a Schiff base hydrogel bio-adhesive based on oxidized chondroitin sulfate (OCS) and polyethylenimine (PEI), and employed different degrees of OCS oxidation to regulate the physicochemical properties of the bio-adhesives. In this system, aldehyde groups of OCS react with amino groups of PEI to form covalent imine crosslinks, while physical hydrogen bonds also contribute as supplementary interactions. The fabricated hydrogel bio-adhesives demonstrated a three-dimensional interconnected microstructure and regulated equilibrium swelling ratios. The rheological tests also confirmed the typical viscoelasticity of the hydrogels and their shear-thinning behavior. The obtained hydrogel bio-adhesives demonstrated rapid and autonomous self-healing ability and strong adhesion to the surfaces of various matrices and wet organs, including wood, glass, metal, plastic, rubber, and heart, liver, spleen, stomach, and lung tissue. Furthermore, an ABTS radical scavenging assay confirmed their potent antioxidant activity. The hydrogels possessed effective antibacterial activities against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. The hydrogels exhibited good hemocompatibility, effective intracellular reactive oxygen species (ROS) scavenging activity, favorable cytocompatibility, and promoted cell proliferation. These results confirmed the fabricated hydrogels via Schiff base connections for biomedical applications and provided a facile design for biomedical hydrogel bio-adhesives. Full article

As crucial weather-scale systems widely affecting the global marine-atmospheric boundary layer, cyclones exert a regulatory effect on aerosols in the marine boundary layer through interrelated physical and chemical processes, including dynamic uplift, strong wind forcing, precipitation scavenging, and cloud microphysical interactions. Following an overview of aerosol properties in the marine boundary layer and synoptic cyclone characteristics, this paper reviews the full-process regulation mechanisms and mutual feedback effects of tropical and extratropical cyclones on aerosol generation, long-range transport, and removal, integrating the latest advances in observational, numerical, and theoretical studies. Cyclone-driven aerosol generation has two key pathways: mechanical fragmentation of sea surfaces in cyclones’ strong wind cores, emitting sea salt aerosols of varying particle sizes, and cyclone-induced disturbances triggering photochemical and heterogeneous reactions that accelerate secondary aerosol formation. Cyclone movement, with strong advection and updrafts, enables cross-ocean long-distance transport and upper troposphere injection of aerosols in the marine boundary layer, altering their global distribution. Wet deposition (rainout and washout) is the dominant removal mechanism, eliminating aerosols and mediating the cyclone–aerosol–cloud feedback loop, where aerosols as cloud condensation nuclei or ice nuclei regulate cyclone intensity, precipitation, and cloud cover. Current challenges (e.g., emission quantification uncertainties, incomplete microphysical understanding, model limitations) and prospects (e.g., enhanced long-term observations, improved model parameterization) are discussed. This review provides a scientific basis for aerosol-climate effect studies under extreme weather and references for related fields. Full article

Background/Objectives: Tissue bio-adhesives have gained significant attention as efficient alternatives to conventional wound closures, which are often hindered by insufficient adhesion and poor biocompatibility. Methods: Inspired by nature’s robust wet-adhesion strategies that use dynamic covalent interactions, we have reported a facilely fabricated hydrogel bio-adhesive based on lactobionic acid-conjugated polyethylenimine (LA-PEI) and oxidized dextran (ODex) via Schiff base linkages. Results: The prepared hydrogels exhibited three-dimensional interconnected porous networks, regulated swelling ratios, typical viscoelasticity, shear-thinning behavior, and self-healing ability. Notably, the swelling ratios of the hydrogels depended on composition, and OLP11 displayed the highest swelling ratio of over 1500%. The hydrogel bio-adhesives exhibited strong adhesion to various surfaces, including glass, metal, plastic, rubber, and wood, as well as to different chicken organs, including the heart, liver, spleen, and stomach. Furthermore, the hydrogels exhibited excellent ABTS radical-scavenging activity, effective intracellular reactive oxygen species (ROS) scavenging, and good hemocompatibility, with hemolysis ratios of all hydrogels close to 0%, below the threshold of 5%. After culturing with NIH 3T3 fibroblasts, the hydrogels demonstrated good cytocompatibility and promoted cell proliferation, with cell viabilities on day 3 reaching over 90%. Conclusions: This design yields multifunctional hydrogel bio-adhesives, showing strong promise for wound care and tissue repair applications. Full article

Ribbed Smoked Sheet (RSS) rubber production in southern Thailand relies extensively on rubber-wood combustion, potentially generating substantial emissions of fine particulate matter and polycyclic aromatic hydrocarbons (PAHs). Despite the economic importance of this sector, systematic characterization of biomass-derived PAHs under tropical monsoonal and coastal conditions remains limited. This study investigates the particle size distribution, concentration levels, seasonal variability, and atmospheric dynamics of PAHs associated with RSS production in Chumphon Province, Thailand. Size-segregated particulate matter was collected using an eight-stage Andersen cascade impactor at two contrasting sites during a seven-month monitoring period from March to September 2025, covering the transition from the late dry/summer season to the rainy season in southern Thailand. Fifteen priority PAHs were quantified by high-performance liquid chromatography with fluorescence detection. Results indicate that emissions from rubber-wood combustion inside smokehouses exhibit a unimodal distribution dominated by submicron particles (MMAD = 0.85 µm; GSD = 2.71). Ambient aerosols displayed a bimodal structure, with an accumulation-mode peak (~0.6 µm) associated with combustion processes and a coarse-mode peak (~4 µm) linked to mechanical and marine aerosol sources. Particle-bound PAHs were predominantly associated with fine particles (~0.59 µm), although seasonal hygroscopic growth under high humidity shifted modal diameters toward ~1.8 µm during the rainy season. PAH profiles were dominated by 3–4 ring compounds characteristic of biomass combustion. Total PAH concentrations exhibited a strong positive correlation with monthly RSS production, while precipitation demonstrated an exponential scavenging effect. Monsoonal circulation and sea spray aerosol (SSA) interactions were identified as key regulators of gas–particle partitioning, transport pathways, and removal efficiency. The findings reveal that the coastal atmosphere of southern Thailand functions as a dynamic multiphase system in which emission intensity, hygroscopic particle growth, monsoonal transport, and wet deposition collectively govern PAH behavior. This study provides the first integrated assessment linking rubber-sheet production dynamics to size-resolved PAH distributions under tropical coastal conditions and offers a scientific foundation for emission mitigation strategies in biomass-dependent agro-industrial regions. Full article

In order to screen the ultrafine grinding methods which are conducive to polyphenol release and biological activity, the peach pomace was respectively treated by dry ultrafine grinding and wet ultrafine grinding, and then the polyphenol extraction, component identification and functional activity evaluation were carried out. The results showed that the content and purity of polyphenols increased by 23.3% and 25.6% respectively after wet ultrafine grinding compared with coarse grinding. The results of HPLC-MS identification showed that chlorogenic acid, D-(-)-quinic acid and catechins were the main polyphenols in the dry superfine grinding residue. However, benzoic acid, quercetin-3-β-D-glucoside and rutin were the main components in the wet superfine grinding residue. The results of antioxidant and anti-inflammatory activity evaluation showed that the peach pomace extract obtained by wet ultrafine grinding had better antioxidant activity (DPPH· and ABTS⁺· scavenging rate and total reducing power reached 80.16%, 47.07% and 1.112 respectively) and anti-inflammatory activity. In the study of α-glucosidase inhibitory activity, it was found that the polyphenols prepared by wet ultrafine grinding had higher inhibitory effect on α-glucosidase (80.22%), and based on the enzyme inhibition kinetics, it showed reversible competitive inhibition on α-glucosidase. Finally, in terms of antibacterial activity, the polyphenol extract prepared by wet ultrafine grinding had the strongest inhibitory effect on Staphylococcus aureus, Escherichia coli and Bacillus subtilis, and its minimum inhibitory concentrations were 3.13, 3.13 and 12.50 mg/mL, respectively. In conclusion, wet ultrafine grinding is more conducive to the efficient extraction of active polyphenols from peach pomace and its biological activity. Full article

Given the urgent need to regulate oxidative stress microenvironments in chronic wound healing, hydrogel dressings that simultaneously integrate antioxidant, antibacterial, mechanically adaptive, and biocompatible properties are highly desirable. In this study, a natural polymer-based composite hydrogel dressing loaded with zinc-quercetin nanozyme (Zn-Q) was designed. The gel skeleton was constructed via a dual network of photocrosslinked methacrylated silk fibroin (SilMA) and mercaptolated hyaluronic acid (HA-SH) via thiol-ene click chemistry, with the catalase (CAT)-like Zn-Q nanozyme encapsulated in situ within the network, thereby achieving synergy between chemical crosslinking and dynamic metal-polyphenol coordination. Systematic characterization revealed that Zn-Q nanozyme adopted a stable octahedral coordination configuration, and its continuous porous structure exposed abundant catalytically active sites. The composite hydrogels exhibited a highly interconnected, three-dimensional (3D) porous morphology, with swelling ratios that increased significantly with Zn-Q nanozyme content (up to around 1082%). Rheological and mechanical tests demonstrated that although incorporating the nanozyme reduced the storage modulus, the reversible physical crosslinks formed via hydrogen bonding and coordination interactions endowed the material with excellent tensile toughness and energy-dissipation capacity, exhibiting typical Mullins softening behavior. Functional evaluation showed that Zn-Q nanozyme conferred superior free radical scavenging capability to the hydrogels and exerted dose-dependent inhibition against both Staphylococcus aureus and Escherichia coli. Furthermore, the hydrogels exhibited favorable adhesion to various wet organs and heterogeneous material surfaces, with hemolysis rates below 5% and cell viability exceeding 100% after 3 days of culturing with fibroblasts, confirming their excellent hemocompatibility and cytocompatibility. This study provides an experimental basis for developing a new type of wound repair materials that integrate antioxidant, anti-infective, and mechanically adaptive properties, holding significant application potential in oxidative stress-related tissue repair fields. Full article

Tissue adhesives are gaining increasing attention as efficient alternatives to conventional wound closure methods, yet their clinical translation is often hindered by insufficient wet adhesion and inadequate biocompatibility. Drawing inspiration from nature’s robust wet-adhesion strategies, particularly dynamic covalent interactions and reversible crosslinking, we report a family of bioinspired composite hydrogels fabricated from 4-carboxyphenylboronic acid-grafted polyethylenimine (4-CPBA-PEI) and polyvinyl alcohol (PVA) that serve as versatile bioadhesives. The polyethylenimine with different molecular weights (18,000, 70,000, and 100,000 Da) was used to prepare the 4-CPBA-PEI derivatives via EDC/NHS-mediated amidation. The resulting hydrogels exhibited three-dimensional interconnected porous networks with tunable pore dimensions and equilibrium swelling ratios (ranging from 400% to 700%), closely correlated with the PEI molecular weight. Rheological measurements confirmed typical viscoelasticity, shear-thinning behavior, and outstanding self-healing performance, which are mainly attributed to hydrogen bonds and dynamic borate ester bonds in the network. The hydrogels firmly adhered to the surfaces of diverse matrices, such as glass, rubber, metal, plastic, wood, human skin, and wet mouse organs. Additionally, the obtained hydrogels exhibited high 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical-scavenging activity (>85%), excellent hemocompatibility (hemolysis rate < 0.5%), and potent intracellular reactive oxygen species (ROS) scavenging activity. Cytocompatibility studies using NIH 3T3 fibroblasts demonstrated low cytotoxicity and favorable cytocompatibility. This biomimetic design yields multifunctional hydrogels that integrate tunable physical properties, wet-surface attachment, self-healing, antioxidant activity, and good biocompatibility, suggesting their potential as wound dressing candidates. Full article

Bacterial infections and excessive reactive oxygen species (ROS) severely impede wound healing. However, traditional hydrogels often lack the integrated antibacterial and antioxidant properties required for effective treatment. To overcome these limitations, a natural thioctic acid (TA)-based multifunctional composite hydrogel (PTA-Arg/SAS) was developed. Arginine (Arg) served as a green inducer for the aqueous ring-opening polymerization of TA. Concurrently, salicylic acid-grafted sericin (SAS) was introduced to inhibit poly(thioctic acid) (PTA) depolymerization via the formation of stable sulfur-aryl (S-Ar) bonds. The hydrogel exhibits self-healing capability, injectability, and robust tissue adhesion to porcine skin (1877 Pa dry; 1663 Pa wet). Furthermore, SAS endowed the system with potent antibacterial (99.1% against E. coli, 97% against S. aureus) and antioxidant activities (98.2% ABTS and 72.7% DPPH radical scavenging rates). In vitro evaluations confirmed the viability of L929 cells (>98% over 3 days) and a negligible hemolysis ratio (<5%). Consequently, this study provides a strategy for fabricating next-generation bioactive dressings for complex wound management. Full article

Atmospheric wet deposition represents a major pathway for the transfer of organic micropollutants into terrestrial and aquatic ecosystems. This study investigates the occurrence and spatial distribution of polycyclic aromatic hydrocarbons (PAHs), phthalate esters (PAEs), and BTEX compounds in rainwater across Northern Serbia (Vojvodina region). Rainwater samples were collected during the 2025–2026 heating season at three locations: a petrochemical site in Kikinda, a traffic- and residentially influenced site in Sremska Mitrovica, and an urban background site in Sombor. Total concentrations showed pronounced spatial variability, with the highest ΣBTEX and ΣPAE levels recorded in Kikinda (∑BTEX = 2.818 μg L^∑1; ∑PAE = 0.930 μg L^∑1). Diagnostic ratios identified a dominant petrogenic signature in Kikinda (LMW/HMW > 1), while pyrogenic sources prevailed in Sremska Mitrovica and Sombor ((Fla/Fla + Pyr) > 0.5). BTEX profiles across all sites were characterised by the absence of benzene and elevated toluene and xylene levels (B/T ≈ 0; T/X > 1). Health risk assessment indicated an acceptable but non-negligible carcinogenic risk from PAHs, particularly for children in industrial areas. These findings highlight the role of precipitation as an efficient scavenger of organic pollutants and emphasise the need for integrated atmospheric–hydrological monitoring frameworks in industrialised regions. Full article

Essential oils (EOs) from wild Calamintha nepeta (Portugal) populations collected in Portugal (Évora) were investigated in order to evaluate the impact of Mediterranean seasonal conditions on their phytochemical composition and biological activity. Essential oil GC-FID and GC-MS analyses revealed distinct seasonal chemotypes, with spring samples dominated by isopulegone/pulegone, whereas autumn samples contained higher proportions of isomenthone and menthol. Antioxidant activity was assessed through lipid peroxidation inhibition, DPPH radical scavenging and ferric reducing power assays, while antibacterial activity was evaluated against multidrug-resistant (MDR) clinical isolates. Seasonal differences were reflected in both EO chemical composition and bioactivity. Autumn samples displayed greater antioxidant potential, with Y1A showing the highest inhibition of lipid peroxidation (IC₅₀ = 0.85 mg/mL) and Y2A exhibiting the highest ferric reducing power. Conversely, spring samples were more active against MDR bacteria. Among them, Y1S showed the broadest antimicrobial spectrum, with MIC values ranging from 465 to 1767 μg/mL. The unusually wet spring season coincided with marked isopulegone accumulation (≈50%), while warmer autumn conditions favoured higher levels of isomenthone and menthol in the EOs. These findings highlight the importance of seasonal environmental conditions in determining the phytochemical profile and bioactive potential of C. nepeta EOs, providing valuable insights for their standardisation and valorisation in pharmaceutical, food and conservation-related applications. Full article

Developing hydrogel dressings that simultaneously achieve robust wet tissue adhesion, mechanical stability, antibacterial activity, and oxidative stress regulation remains challenging. In this study, a dual-network poly (thioctic acid)/ammonium glycyrrhizinate (PTA/AG) hydrogel was developed through thermally induced ring-opening polymerization (ROP) of TA and sodium thioctate (TA-Na) to form a primary network, followed by the formation of an AG-driven secondary network during cooling. TA-Na improved the aqueous processability of TA, while the AG secondary network reinforced the stability of the PTA primary network. The resulting hydrogel exhibited a crossover strain of 454% and a wet adhesion strength of up to 16.37 kPa on porcine skin. In addition, the hydrogel showed strong antibacterial activity against S. aureus (>99%), high cytocompatibility (>95% cell viability), and effective free-radical-scavenging activity (>77% scavenging of both DPPH and ABTS radicals). Notably, the hydrogel exhibited effective intracellular antioxidant activity, reducing ROS levels to near those of the control group and increasing SOD activity by approximately 13-fold and the GSH/GSSG ratio by 97.83% relative to the H₂O₂ group. Overall, the PTA/AG hydrogel is a promising candidate for multifunctional wound dressing applications. Full article

This study examines the meteorological and gaseous pollutant drivers of PM_2.5 under mild, moderate, and severe pollution conditions in the Beijing–Tianjin–Hebei region, with the aim of supporting sustainable air quality management. Daily observations from approximately 65 monitoring stations from 1 November 2021 to 31 October 2024 were used, including PM_2.5, four gaseous pollutants (SO₂, NO₂, CO, and O₃), and five meteorological variables: temperature, pressure, relative humidity, precipitation, and wind speed. A CatBoost–SHAP framework was adopted, with CatBoost used for station-level spatial prediction of PM_2.5 and SHAP applied to interpret variable contributions. Based on predefined PM_2.5 thresholds, 425 pollution days were classified into those three pollution-level scenarios. These pollution days occurred mainly in winter and spring, with higher frequencies in Handan, Baoding, and Shijiazhuang, followed by Tianjin and Beijing. The model performed well across the three pollution-level scenarios. The severe-pollution scenario achieved the highest R², indicating a clearer spatial structure under high-PM_2.5 conditions. Although absolute RMSE and MAE increased with pollution severity, their normalized values changed little, suggesting that larger errors mainly reflected stronger spatial heterogeneity at higher PM_2.5 concentrations. SHAP results showed that CO, precipitation, wind speed, and temperature dominated the prediction structure. CO was the most stable and influential predictor, but its importance should be interpreted as an indicator of combustion-related pollution accumulation rather than direct causality. Precipitation represented event-dependent wet scavenging, wind speed reflected dispersion conditions, and temperature captured seasonal and thermal background effects. SHAP dependence analysis further indicated that CO had the clearest direct dependence, whereas wind speed and temperature were more background-dependent, and precipitation acted as an episodic nonlinear regulator. Full article