Search Results (6,535)

Following the implementation of the Shanghai Clean Air Act, this study investigates the evolution of air pollution in central Shanghai (Putuo District) by analyzing continuous monitoring data (2016–2020) and chemical speciation of particulate matter (2017–2018). The results confirm a transition toward a “low exceedance rate and low background concentration” regime. However, short-term exceedance episodes persist, generally occurring in winter and spring, with significantly amplified diurnal variations on exceedance days. Distinct patterns emerged between PM fractions: PM₁₀ exceedances were characterized by a single morning peak linked to traffic-induced coarse particles, while PM₂.₅ exceedances showed synchronized diurnal peaks with NO₂, suggesting a stronger contribution from vehicle exhaust. Source apportionment revealed that mineral components (21.61%) and organic matter (OM, 21.02%) dominated in PM₁₀, implicating construction and road dust. In contrast, PM_2.5 was primarily composed of OM (26.73%) and secondary inorganic ions (dominated by nitrate), highlighting the greater importance of secondary formation. The findings underscore that sustained PM_2.5 mitigation requires targeted control of gasoline vehicle emissions and gaseous precursors. Full article

Atherosclerosis remains a leading cause of cardiovascular mortality despite advances in pharmacological and interventional therapies. Current treatment approaches face limitations including systemic side effects, inadequate local drug delivery, and restenosis following vascular interventions. Gel-based technologies offer unique advantages through tunable mechanical properties, controlled degradation kinetics, high drug-loading capacity, and potential for stimuli-responsive therapeutic release. This review examines gel platforms across multiple scales and applications in atherosclerosis research and intervention. First, gel-based in vitro models are discussed. These include hydrogel matrices simulating plaque microenvironments, three-dimensional cellular culture platforms, and microfluidic organ-on-chip devices. These devices incorporate physiological flow to investigate disease mechanisms under controlled conditions. Second, therapeutic strategies are addressed through macroscopic gels for localized treatment. These encompass natural polymer-based, synthetic polymer-based, and composite formulations. Applications include stent coatings, adventitial injections, and catheter-delivered depots. Natural polymers often possess intrinsic biological activities including anti-inflammatory and immunomodulatory properties that may contribute to therapeutic effects. Third, nano- and microgels for systemic delivery are examined. These include polymer-based nanogels with stimuli-responsive drug release responding to oxidative stress, pH changes, and enzymatic activity characteristic of atherosclerotic lesions. Inorganic–organic composite nanogels incorporating paramagnetic contrast agents enable theranostic applications by combining therapy with imaging-guided treatment monitoring. Current challenges include manufacturing consistency, mechanical stability under physiological flow, long-term safety assessment, and regulatory pathway definition. Future opportunities are discussed in multi-functional integration, artificial intelligence-guided design, personalized formulations, and biomimetic approaches. Gel technologies demonstrate substantial potential to advance atherosclerosis management through improved spatial and temporal control over therapeutic interventions. Full article

An inorganic–organic hybrid nano-adsorbent was prepared by chemical immobilisation of an organic Schiff base Cu (II) ion receptor, DHB ((E)-N-(1-(2-hydroxy-6-methyl-4-oxo-4H-pyran-3-yl) ethylidene) benzohydrazide), a selective dehydroacetic acid-based chemosensor, onto a mesoporous silica support. In order to prepare the sorbent, the silylating agent was anchored onto the silica. During this procedure, 3-Chloropropyl trimethoxy silane (CPTS) was attached to the surface, increasing hydrophobicity. By immobilising DHB onto the CPTS platform, the silica surface was activated, and as a result the coordination chemistry of the Schiff base generated a hybrid adsorbent with the capability to rapidly sequestrate Cu (II) ions from wastewater, as an answer to combat growing Waste Electrical and Electronic Equipment (WEEE) contamination in water supplies, in the wake of a prolonged consumerism mentality and boom in cryptocurrency mining. The produced hybrid materials were characterised by FTIR, proximate and ultimate analysis, nitrogen physisorption, PXRD, SEM, and TEM. The parameters influencing the removal efficiency of the sorbent, including pH, initial metal ion concentration, contact time, and adsorbent dosage, were optimised to achieve enhanced removal efficiency. Under optimal conditions (pH 7.0, adsorbent dosage 3 mg, contact time of 70 min, and 25 °C), Cu (II) ions were quantitatively sequestered from the sample solution; 93.1% of Cu (II) was removed under these conditions. The adsorption was found to follow pseudo-second-order kinetics, and Langmuir model fitting affirmed the monolayer adsorption. Full article

The Wufeng–Longmaxi (WF–LMX) shale gas reservoirs at depths > 3500 m in the Lu203–Yang101 well block, southern Sichuan Basin, possess great exploration potential, but their reservoir characteristics and high-production mechanisms remain unclear. In this study, we employed multi-scale analyses—including core geochemistry, X-ray diffraction (XRD), scanning electron microscopy (SEM), low-pressure N₂ adsorption, and nuclear magnetic resonance (NMR)—to characterize the macro- and micro-scale characteristics of these deep shales. By comparing with shallower shales in adjacent areas, we investigated differences in pore structure between deep and shallow shales and the main controlling factors for high gas-well productivity. The results show that the Long 11 sub-member shales are rich in organic matter, with total organic carbon (TOC) content decreasing upward. The mineral composition is dominated by quartz (averaging ~51%), which slightly decreases upward, while clay content increases upward. Porosity ranges from 1% to 7%; the Long11-1-3 sublayers average 4–6%, locally >6%. Gas content correlates closely with TOC and porosity, highest in the Long11-1 sublayer (6–10 m³/t) and decreasing upward, and the central part of the study area has higher gas content than adjacent areas. The micro-pore structure exhibits pronounced stratigraphic differences: the WF Formation top and Long11-1 and Long11-3 sublayers are dominated by connected round or bubble-like organic pores (50–100 nm), whereas the Long11-2 and Long11-4 sublayers contain mainly smaller isolated organic pores (5–50 nm). Compared to shallow shales nearby, the deep shales have a slightly lower proportion of organic pores, smaller pore sizes with more isolated pores, inorganic pores of mainly intraparticle types, and more developed microfractures, confirming that greater burial depth leads to a more complex pore structure. Type I high-quality reservoirs are primarily distributed from the top of the WF Formation to the Long11-3 sublayer, with a thickness of 15.6–38.5 m and a continuous thickness of 13–23 m. The Lu206–Yang101 area has the thickest high-quality reservoir, with a cumulative thickness of Type I + II exceeding 60 m. Shale gas-well high productivity is jointly controlled by multiple factors: an oxygen-depleted, stagnant deep-shelf environment, with deposited organic-rich, biogenic siliceous shales providing the material basis for high yields; abnormally high pore-fluid pressure with preserved abundant large organic pores and increased free gas content; and effective multi-stage massive fracturing connecting a greater reservoir volume, which is the key to achieving high gas-well production. This study provides a scientific basis for evaluating deep marine shale gas reservoirs in southern Sichuan and understanding the enrichment patterns for high productivity. Full article

Organic optoelectronic devices receive appreciable attention due to their low cost, ecology, mechanical flexibility, band-gap engineering, brightness, and solution process ability over a broad area. In this study, we designed and studied organic light-emitting diodes (OLEDs) consisting of an assembly of natural dyes, extracted from noble fir leaves (evergreen) and blue hydrangea flowers mixed with poly-methyl methacrylate (PMMA) as light emitters. We experimentally demonstrate the effective conversion of blue light emitted by an inorganic laser/photodiode into longer-wavelength red and green tunable photoluminescence due to the excitation of natural dye–PMMA nanostructures. UV-visible absorption and photoluminescence spectroscopy, ellipsometry, and Fourier transform infrared methods, together with optical microscopy, were performed for confirming and characterizing the properties of light-emitting diodes based on natural dyes. We highlighted the optical and physical properties of two different natural dyes and demonstrated how such characteristics can be exploited to make efficient LED devices. A strong pure red emission with a narrow full-width at half maximum (FWHM) of 23 nm in the noble fir dye–PMMA layer and a green emission with a FWHM of 45 nm in blue hydrangea dye–PMMA layer were observed. It was revealed that adding monolayer MoS₂ to the nanostructures can significantly enhance the photoluminescence of the natural dye due to a strong correlation between the emission bands of the inorganic–organic emitters and back mirror reflection of the excitation blue light from the monolayer. Based on the investigation of two natural dyes, we demonstrated viable pathways for scalable manufacturing of efficient hybrid OLEDs consisting of assembly of natural-dye polymers through low-cost, purely ecological, and convenient processes. Full article

Organic and inorganic peroxides can induce intracellular redox homeostasis. In this study, a γ-cyclodextrin/genistein inclusion complex (γ-CD/GEN) was constructed to systematically elucidate the molecular mechanism by which it catalyzes GPx4-mediated peroxide reduction. The results indicate that the incorporation of γ-CD effectively disrupts the aggregated state of GEN, achieving an encapsulation efficiency (EE) exceeding 40%. Surface-enhanced Raman spectroscopy (SERS) analysis reveals significant differences in the catalytic behavior of γ-CD/GEN toward cumene hydroperoxide (CHP) and hydrogen peroxide (H₂O₂): the reduction efficiency of CHP depends on both the concentration of γ-CD/GEN and GPx4, whereas the reduction of H₂O₂ is primarily regulated by the concentration of γ-CD/GEN. Isotope effect studies demonstrate that the reduction of CHP relies more on radical-initiated reactions, while the reduction of H₂O₂ involves proton transfer, with the differences in reduction rates correlating with their respective redox mechanisms. Molecular docking and molecular dynamics simulations further confirm that γ-CD/GEN can stably bind to the Sec (Cys)-46 site in the active center of GPx4, thereby enhancing its catalytic activity. This study provides a theoretical basis for the development of antioxidant strategies based on the precise regulation of enzyme activity. Full article

Dorsomorphin, a pyrazolo[1,5-a]pyrimidine derivative, inhibits the bone morphogenetic protein (BMP) pathway by targeting the type I BMP receptors active in receptor-like kinases. However, the investigation of its—and its derivatives’—antiproliferative activity towards endothelial and cancer cell lines still requires reinforcement with additional studies. In the presented work, several dorsomorphin derivatives have been efficiently synthesized, based on a previously reported synthetic protocol with minor modifications. The endeavor was reinforced by a molecular docking study on the interactions of the designed derivatives with various protein targets, while the inhibitory effects of the synthesized novel molecules on the proliferation of murine leukemia cells (L1210), human T-lymphocyte cells (CEM), human cervix carcinoma cells (HeLa), and endothelial cells (human dermal microvascular, HMEC-1, and bovine aortic endothelial cells, BAECs) were investigated. Among the compounds tested, diphenol 22, emerged as the most promising bioactive lead since it demonstrated half-maximal inhibitory concentration (IC₅₀) values below 9 μM in all tested lines except HeLa cells. In the same context, the carbamate derivative 6 was determined as a potent inhibitor of endothelial cell proliferation in BAECs at a low micromolar range. In conclusion, the presented work not only reveals promising antiproliferative dorsomorphin derivatives but also sets the basis for further exploitation of dorsomorphin’s bioactive portfolio, based on bioactivity results and molecular modeling calculations. Full article

Improving the thermal utilisation of organic production waste to generate energy is integral to solving one of the most pressing issues of our time: transitioning away from fossil fuels. In this context, the thermal utilisation of organic waste, particularly sewage sludge (SS) and lignin-containing by-products from the biochemical industry, is of considerable scientific and practical interest. This study provides a thorough analysis of the co-combustion processes involving SS, lignin-based pellets and briquettes, and their mixtures with various component ratios. The aim of the work is to evaluate the fuel properties, thermokinetic characteristics, and potential for synergistic interactions during joint fuel combustion, considering the mechanical impact on lignin during granulation. The aim is to optimise conditions for the thermal utilisation of industrial waste. The study employed standard analytical methods: the thermophysical properties of the fuels were determined; morphological analysis of the particle surface was conducted using scanning electron microscopy; and X-ray fluorescence analysis was performed to identify the inorganic oxide phase. It has been established that lignin briquettes have the highest lower heating value, exceeding that of lignin pellets and sewage sludge by 7% and 27%, respectively. Thermogravimetric analysis (TGA) in an oxidising atmosphere (air, heating rate of 10 °C/min) made it possible to determine the following key combustion parameters: the ignition temperature of the coke residue (T_i); the temperature at which oxidation is complete (T_b); the maximum combustion rate (R_max); and the combustion efficiency index (Q). The ignition temperature of the coke residue was 262.1 °C for SS, 291.8 °C for lignin pellets, and 290.0 °C for lignin briquettes. Analysis of co-combustion revealed non-linear behaviour in the thermograms, indicating synergistic effects, which are manifested by a decrease in the maximum combustion rate compared to the additive prediction, particularly in mixtures with a moderate lignin content (25–50%). It was established that the main synergistic interactions between the mixture components occurred during moisture evaporation and the combustion of coke residue. These results are valuable for designing and operating power plants that focus on co-combusting industrial organic waste, and they contribute to the development of thermal utilisation technologies within closed production cycles. Full article

Nitrogen (N) management remains a primary challenge in organic grain systems, particularly in rotations where heavy N-consuming crops, such as corn and wheat, follow one another. Daikon radish (Raphanus sativus L.) is widely adopted for its ability to scavenge residual soil nitrate between cash crops; yet the subsequent availability of scavenged N to the following crop is inconsistent and often negligible. This 4-year field study (2014–2017) at the University of Minnesota Southwest Research and Outreach Center evaluated whether planting daikon radish in polyculture with berseem clover, and either annual oats or winter rye could improve N retention and timed release compared to daikon radish monoculture. Three cover crop treatments were tested across three common organic management systems: no manure with no tillage, manure with tillage, and manure plus shallow tillage incorporation before cover crop seeding. Polycultures, especially those including winter rye, produced significantly more fall biomass (up to 6435 kg ha⁻¹) than daikon radish monoculture (573–1272 kg ha⁻¹). Manure incorporation consistently increased total and daikon radish biomass, as well as the percent living cover. Despite substantial biomass differences, mid-season and fall soil inorganic N, potentially mineralizable N, permanganate-oxidizable C, and enzyme activities showed few consistent treatment effects. Corn grain yield was highest following manure with tillage incorporation but was significantly reduced after the winter rye polyculture in all years, likely due to N immobilization and delayed corn planting caused by late rye termination under wet spring conditions. Results indicate that while polycultures with winter rye maximize biomass and soil cover, they do not reliably enhance N recycling to the subsequent organic corn crop and can reduce yield. Full article

Designing the high-performance polyimides (PIs) for the biomimetic structures, which are used in extreme conditions, remains greatly challenging, due to the conflict between processability and thermal stability. Here, we report a series of silicon–alkyne-functionalized diamine-based polyimides that exhibit remarkable processability and thermal stability. The incorporation of bulky siloxy groups disrupts chain packing and increases free volume, enabling excellent solubility in polar solvents, while the rigid fluorene core enhances chain stiffness. DFT calculations confirm twisted molecular geometries (Si bond angle ≈ 103°, dihedral angle ≈ 89°) which weak π–π stacking, while heterogeneous electrostatic potentials enable favorable noncovalent interactions (e.g., C–F···H–C), promoting solvent diffusion. After thermal curing, the obtained product shows a high decomposition temperature (T_d5% = 560 °C), char yield of 72.0% at 800 °C, and glass transition temperature (T_g) of 354.6 °C. Meanwhile, locally planar fluorene units retain inherent thermal stabilization benefits through constrained rotational mobility. These results demonstrate a spatially decoupled siloxy–alkyne design that synergistically enhances molecular flexibility, disorder, and electronic stability, offering a molecular strategy for tailoring PI-based matrices to meet the demands of emerging biomimetic architectures and other high-performance composites operating under severe thermal loads. Full article

Produced water (PW) generated from oil and gas operations poses a significant environmental challenge due to its high salinity and complex organic–inorganic composition. This study evaluates forward osmosis (FO) as an energy-efficient approach for PW treatment by comparing a commercial cellulose triacetate (CTA) membrane and a fabricated electrospun nanofibrous membrane, both modified with a zwitterionic sulfobetaine methacrylate/polydopamine (SBMA/PDA) coating. Fourier Transform Infrared Spectroscopy (FTIR) spectra verified the successful incorporation of SBMA and PDA through the appearance of characteristic sulfonate, quaternary ammonium, and catechol/amine-related vibrations. Scanning electron microscopy (SEM) imaging revealed the intrinsic dense surface of the CTA membrane and the highly porous nanofibrous architecture of the electrospun membrane, with both materials showing uniform coating coverage after modification. Complementary analyses supported these observations: X-ray Photoelectron Spectroscopy (XPS) confirmed the presence of nitrogen, sulfur, and chlorine containing functionalities associated with the zwitterionic layer; Thermogravimetric Analysis (TGA) demonstrated that surface modification did not compromise the thermal stability of either membrane; and contact-angle measurements showed substantial increases in surface hydrophilicity following modification. Gas chromatography–mass spectrometry (GC–MS) analysis of the Permian Basin PW revealed a chemically complex mixture dominated by light hydrocarbons, alkylated aromatics, and heavy semi-volatile organic compounds. FO experiments using hypersaline PW demonstrated that the fabricated membrane consistently outperformed the commercial membrane under both MgCl₂ and Na₃PO₄ draw conditions, achieving up to ~40% higher initial water flux and total solids rejection as high as ~62% when operated with 2.5 M Na₃PO₄. The improved performance is attributed to the nanofibrous architecture and zwitterionic surface chemistry, which together reduced fouling and reverse solute transport. These findings highlight the potential of engineered zwitterionic nanofibrous membranes as robust alternatives to commercial FO membranes for sustainable produced water treatment. Full article

This work explores a novel and efficient synthetic approach to a new class of boron cluster derivatives via the nucleophilic addition of stabilized phosphorus ylides, Ph₃P=CHR² (R² = COOEt, CN), to a series of nitrilium salts of the closo-decaborate anion, [2-B₁₀H₉NCR¹]⁻ (R¹ = Me, Et, ⁿPr, ⁱPr, Ph). The reaction proceeds regio- and stereospecifically, affording a diverse range of iminoacyl phosphorane derivatives, [2-B₁₀H₉NH=C(R¹)C(PPh₃)R²]⁻, in high isolated yields (up to 95%). The obtained compounds (10 examples) were isolated as tetrabutylammonium or tetraphenylphosphonium salts and thoroughly characterized by multinuclear NMR (¹¹B, ¹H, ¹³C, ³¹P), high-resolution mass spectrometry, and single-crystal X-ray diffraction. The reaction feasibility was found to be strongly influenced by the steric hindrance of the R¹ group. Furthermore, the practical utility of these novel hybrids was demonstrated by employing the [2-B₁₀H₉NH=C(CH₃)C(COOC₂H₅)=PPh₃]⁻ anion as a highly effective membrane-active component in ion-selective electrodes. The developed tetraphenylphosphonium (TPP⁺) sensor exhibited a near-Nernstian response, a low detection limit of 3 × 10⁻⁸ M, and excellent selectivity over a range of common inorganic and organic cations, showcasing the potential of closo-borate-based ionophores in analytical chemistry. Full article

The structural application of Fiber-Reinforced Polymers (FRP) is significantly hindered by their inherent thermal sensitivity. This paper presents a comprehensive review of the fire performance of FRP materials and FRP-concrete systems, spanning from material-scale degradation to structural-scale response. Distinct from previous studies, this review explicitly distinguishes between the fire behavior of internally reinforced FRP-reinforced concrete members and externally applied systems, including Externally Bonded Reinforcement (EBR) and Near-Surface Mounted (NSM) techniques. The thermal and mechanical degradation mechanisms of FRP constituents—specifically reinforcing fibers and polymer matrices—are first analyzed, with a focused discussion on the critical role of the glass transition temperature T_g. A detailed comparative analysis of the pros and cons of organic (epoxy-based) and inorganic (cementitious) binders is provided, elaborating on their respective bonding mechanisms and thermal stability under fire conditions. Furthermore, the effectiveness of various fire-protection strategies, such as external insulation systems, is evaluated. Synthesis of existing research indicates that while insulation thickness remains the dominant factor governing the fire survival time of EBR/NSM systems, the irreversible thermal degradation of polymer matrices poses a primary challenge for the post-fire recovery of FRP-reinforced structures. This review identifies critical research gaps and provides practical insights for the fire-safe design of FRP-concrete composite structures. Full article

Volatile aromatic compounds (BTEX: benzene, toluene, ethylbenzene, and xylenes) are toxic and odor-active volatile organic compounds of environmental and health concern. Conventional biofiltration systems often rely on organic packing materials that deteriorate over time, motivating the evaluation of more durable inorganic alternatives. In this study, andesite, a volcanic rock, was assessed as a packing material in a laboratory-scale biotrickling filter (BTF) for the removal of BTEX from air streams. The reactor was operated under controlled conditions at different empty-bed residence times, and BTEX concentrations were monitored using TD-GC/MS. Removal performance was interpreted in relation to biofilm development, supported by physicochemical characterization of the packing material and contextual microbial analysis of the microbial community structure by amplicon sequencing. The results showed that the andesite-packed BTF achieved high BTEX removal efficiencies after an acclimation period, with stable operation under the tested conditions. Microbial analysis revealed the dominance of bacterial groups commonly associated with aerobic degradation of aromatic hydrocarbons. These findings indicate that andesite can function as a mechanically stable and biologically compatible inorganic support for BTEX treatment in biotrickling filters at the laboratory scale. The study is limited to bench-scale operation and community-level microbial analysis; therefore, further work is required to evaluate long-term performance, scale-up potential, and functional metabolic interactions. Full article

This study investigates the Lower Cretaceous Madongshan Formation in the Liupanshan Basin, a classic saline lacustrine succession, to elucidate the key mechanisms for high-quality source rock development. An integrated approach combining organic geochemistry (Rock-Eval, Gas Chromatography–Mass Spectrometry [GC-MS], δ¹³C) and inorganic elemental geochemistry (X-ray Fluorescence [XRF]) was applied to a well-characterized outcrop section. The results reveal that the Madongshan Formation contains mature, oil-prone source rocks dominated by Type II₁ and II₂ kerogen. Geochemical proxies consistently indicate deposition within an arid to semi-arid climate, which drove the formation of a stratified, saline-to-hypersaline water column with persistent bottom-water anoxia (Pristane/Phytane [Pr/Ph] < 0.5). Isotopic and biomarker data confirm a mixed source input, with an average contribution of approximately 55% from aquatic organisms supplemented by a significant terrestrial influx. Based on these findings, we propose a “Salinity-Driven Preservation” model. This model posits that climate-induced salinity played a critical role in establishing a persistent halocline, leading to an intensely anoxic “preservation factory” at the lake bottom. Current evidence suggests that this exceptional preservation efficiency was a pivotal factor compensating for moderate productivity to control organic matter enrichment. This study provides a robust framework for predicting source rock quality in the Liupanshan Basin and serves as a valuable analogue for other saline lacustrine systems. Full article