Search Results (2,356)

Background/Objectives: Royal jelly is a biologically active bee product with a complex chemical composition and diverse biological properties. This study aimed to comprehensively characterize the phytochemical composition of royal jelly and evaluate its antioxidant capacity, enzyme-inhibitory abilities, and potential molecular interactions with target enzymes. Methods: The phytochemical profile of royal jelly was characterized using liquid chromatography–tandem mass spectrometry (LC–MS/MS). Total phenolic and flavonoid contents were determined spectrophotometrically. Antioxidant activity was evaluated using DPPH^•, ABTS^•+, and DMPD^•+ scavenging assays, together with Fe³⁺, CUPRAC, and FRAP reducing methods. Enzyme-inhibitory abilities were assessed against human carbonic anhydrase I and II (hCA I and hCA II), acetylcholinesterase (AChE), butyrylcholinesterase (BChE), α-glucosidase, and α-amylase. Molecular docking analyses were subsequently performed to investigate the interactions of major identified compounds with enzyme active sites. Results: LC–MS/MS analysis revealed a diverse profile of phenolic and flavonoids, including quinic acid, caffeic acid, chlorogenic acid, p-coumaric acid, apigenin, luteolin, kaempferol, and amentoflavone. Royal jelly exhibited considerable antioxidant activity, with IC₅₀ values of 29.33, 29.20, and 21.65 μg/mL in the DPPH^•, ABTS^•+, and DMPD^•+ scavenging assays, respectively. It also demonstrated notable reducing capacity in Fe³⁺ reduction (0.702 μg/mL), CUPRAC (1.444 μg/mL), and FRAP (0.964 μg/mL) assays. Significant inhibitory ability was observed against hCA I (1.12 μg/mL), hCA II (1.33 μg/mL), AChE (1.44 μg/mL), BChE (1.52 μg/mL), α-glucosidase (2.04 μg/mL), and α-amylase (2.11 μg/mL). Docking analyses indicated that major constituents, particularly quinic acid, could interact with key catalytic residues through hydrogen bonding and electrostatic interactions. Conclusions: Royal jelly possesses a rich polyphenolic profile accompanied by substantial antioxidant and multi-target enzyme-inhibitory abilities. These findings provide biochemical and molecular evidence supporting the potential of royal jelly as a functional food and nutraceutical ingredient and highlight its value as a source of bioactive compounds for further pharmacological investigation. Full article

Cryogenic liquid-level measurement requires a distinct and repeatable liquid–vapor interface signal. In this study, a commercial coherent optical frequency-domain reflectometry (C-OFDR) instrument is used to interrogate an electrically heated SMF-28 probe. The contributions are an analysis of the heat-transfer-based sensing principle, a bonded probe package, and experimental evaluation of interface stability and repeatability. A separate enameled Ni-Cr wire and the fiber are bonded with thermally conductive adhesive before insertion into a sleeve, providing controlled thermal contact. The interface is located from the maximum magnitude of the axial gradient in the Rayleigh-based temperature-equivalent profile. In liquid nitrogen, an approximately 0.4 m active probe was interrogated through an approximately 63 m passive lead. Ten quasi-static readings yielded a zero-intercept slope of 0.9732, R² = 0.9998, an MAE of 0.251 mm, and a maximum absolute error of 0.630 mm relative to a ruler. The stored coordinate interval was 0.1 mm but is not an absolute-accuracy specification. Tests at 200 Hz and approximately 23.5 Hz, together with ten repeated room-temperature water profiles, showed that the heated interface remained distinguishable and repeatable under the tested conditions. Cryogenic vibration, dynamic response, long-term drift, and qualification for liquid oxygen or liquid hydrogen remain to be evaluated. Full article

To reduce the risk associated with 3-nitropropanoic acid (3-NPA) contamination, an efficient and accurate analytical method for 3-NPA determination in sugarcane samples was established by combining magnetic solid-phase extraction (MSPE) with high-performance liquid chromatography–tandem mass spectrometry (HPLC-MS/MS). Owing to the hydrogen bonding and hydrophobic interactions, the mixed strong cation exchange (MCX) magnetic adsorbent showed effective extraction ability toward 3-NPA. Only 2 mL of organic solvent was consumed during the MSPE procedure, and the operation time was short (5 min). The limits of detection were 0.02 μg kg⁻¹ for sugarcane juice and 0.04 μg kg⁻¹ for sugarcane. The developed method showed satisfactory spiked relative recoveries (96.9–105.4%) and good precision values (RSD 1.4–9.7%). MCX-MSPE cleanup provided partial mitigation of matrix suppression, with the absolute matrix effect value rising from 39.4% to 57.1%. This study provides an efficient analytical alternative for the determination of 3-NPA in sugarcane samples. Full article

Underground hydrogen storage in porous formations requires numerical models able to represent multiphase flow, gas dissolution, diffusion, capillary effects, and gas mixture behaviour under conditions that may involve temperature changes, salinity and deformation. This work presents a general abiotic compositional formulation for hydrogen mass transport in water-wet porous media and its implementation in a new numerical model, X2H+. The formulation describes advective, diffusive and dispersive transport in gas and liquid phases and incorporates non-ideal gas behaviour, hydrogen dissolution in brine, water-vapour equilibrium, salinity-dependent liquid properties, porosity-dependent intrinsic permeability, and porosity-dependent capillary behaviour. The reservoir-scale transport response of X2H+ was numerically qualified against a multi-code benchmark involving hydrogen injection into an initially water-saturated axisymmetric aquifer. The model reproduces the gas-saturation evolution reported for the benchmark, with deviations comparable to those observed among the reference numerical models. The formulation also limits additional material-information demand by evaluating many extended transport terms through transferable equations of state, thermodynamic correlations, and physicochemical relationships rather than through new porous-medium-specific parameters. X2H+ provides a flexible basis for advanced underground hydrogen storage simulations while retaining a manageable material-characterisation requirement. Full article

Liquid organic hydrogen carriers (LOHC) have emerged as a promising technology for the safe, efficient, and reversible storage and transportation of hydrogen, offering a viable pathway toward the development of a hydrogen-based economy. Despite the rapid expansion of this research field, a comprehensive understanding of its scientific evolution, intellectual structure, and emerging research directions remains limited. This study presents a comprehensive bibliometric and thematic analysis of LOHC research based on 1140 publications indexed in the Scopus database between 2007 and 2025. Bibliometric indicators, scientific mapping, Bradford’s and Lotka’s laws, thematic evolution, and strategic thematic mapping were performed using VOSviewer and Bibliometrix/Biblioshiny. The results reveal an exponential increase in scientific production after 2016, reflecting the growing global interest in LOHC technologies. Bradford’s law identified a highly concentrated publication landscape dominated by a small core of specialized journals, whereas Lotka’s law demonstrated that scientific production is driven by a limited group of highly productive authors. Keyword network and thematic evolution analyses show a clear transition from fundamental hydrogen storage concepts toward advanced catalyst development, molecular design, quantum chemical calculations, machine learning, techno-economic assessment, and hydrogen transport applications. Strategic thematic mapping further indicates that computational methodologies and sustainability-oriented analyses are becoming emerging drivers of future research. Overall, this study provides a comprehensive overview of the conceptual, intellectual, and thematic evolution of LOHC research while identifying the principal scientific trends and technological opportunities expected to shape the next generation of hydrogen storage systems. Full article

Hydrogen is expected to play a key role in the transition towards sustainable energy systems, although its storage and transportation remain major barriers to its widespread deployment. Chemical hydrogen carriers, including methanol, liquid organic hydrogen carriers (LOHCs) and ammonia, represent promising solutions because they enable hydrogen storage and transport under practical conditions using current infrastructure. For hydrogen recovery from these chemicals, membrane reactors provide an attractive process-intensification strategy by integrating catalytic reactions and hydrogen separation within a single unit. This configuration enhances hydrogen recovery, shifts the thermodynamic equilibrium towards higher conversions and simultaneously delivers high-purity fuel-cell-grade hydrogen while reducing downstream purification requirements. In this context, the present review critically discusses the current state of the art in membrane reactor technology for hydrogen recovery from the most relevant chemical hydrogen carriers. In this context, catalytic systems, membrane configurations and reactor performance are compared across the most promising carrier alternatives. Finally, the main technological challenges and future opportunities for the industrial implementation of these systems are identified. Full article

Dielectric relaxation of n-propanol and isopropanol was examined by radio-frequency measurements at seven fixed frequencies (0.3–32 MHz) over +20 to −160 °C and by openCOSMO-RS calculations. Apparent characteristic times were assigned from dielectric-loss maxima and analyzed with Arrhenius and Eyring formalisms. Nine temperature scans were available for each sample, obtained with three independent measuring capacitors and three repeat scans per capacitor. Capacitor-specific Arrhenius fits gave apparent activation energies of 21.30 ± 0.16 kJ mol⁻¹ (SD; 95% CI of the mean 20.91–21.69) for n-propanol and 21.99 ± 0.16 kJ mol⁻¹ (95% CI 21.60–22.38) for isopropanol. A conservative Welch comparison of the three independent-capacitor estimates gave ΔE_a = 0.687 kJ mol⁻¹ (95% CI 0.332–1.042, p = 0.0058). Although this sub-kJ difference is statistically distinguishable in the cell-level analysis, it is not considered to have mechanistic significance because systematic temperature uncertainty and unresolved spectral overlap are not included in that comparison. Eyring activation enthalpies are 19.60 ± 0.15 and 20.23 ± 0.15 kJ mol⁻¹ (SD), respectively. Entropy and Gibbs-energy values are reported only as apparent quantities under κ = 1. openCOSMO-RS yields liquid-to-n-hexane infinite-dilution transfer enthalpies of 30.5 and 28.0 kJ mol⁻¹. These transfer quantities include hydrogen bonding and nonspecific solvation, dispersion, and packing contributions and are therefore not identified with hydrogen-bond enthalpies. Literature calorimetry gives lower neat-alcohol hydrogen-bonding enthalpy magnitudes of approximately 17 kJ mol⁻¹. Kirkwood factors above unity indicate strong static orientational correlation. Because the seven-frequency window does not independently resolve the Debye and structural α processes, the kinetic parameters are interpreted as effective descriptors of the dominant dielectric-loss process rather than mode-specific barriers. Full article

Supercritical water gasification (SCWG) is a promising technology for the efficient and potentially lower-pollutant conversion of coal. However, char formation caused by the polycondensation of aromatic structures hinders the popularization and application of this technology. Promoting the depolymerization of aromatic structures is the key to suppressing char formation and achieving efficient coal gasification. Both methanol and potassium carbonate (K₂CO₃) can facilitate the cleavage of aromatic structures. To promote aromatic depolymerization and realize efficient coal gasification, this study systematically investigated the effects of different methanol concentrations and K₂CO₃–methanol coupling systems on the SCWG of Zhundong coal. The results showed that neither methanol alone nor its coupling with K₂CO₃ enhanced the gasification performance of Zhundong coal, as judged by carbon gasification efficiency (CE), hydrogen gasification efficiency (HE), and gas yield, but they altered the distribution of gaseous and liquid products. The co-gasification of methanol and Zhundong coal promoted the generation of CH₄ and C₂H₆ at an appropriate methanol concentration. Specifically, 2.5 wt% methanol accelerated the cleavage of aromatic structures to produce naphthalene and its derivatives, whereas high-concentration methanol mainly promoted the formation of naphthalene and phenolic compounds. In the K₂CO₃–methanol coupling system, K₂CO₃ preferentially catalyzes methanol reforming, thereby weakening the direct catalytic effect of K₂CO₃ on coal gasification. Nevertheless, compared with the theoretical yields calculated assuming no methanol–coal interaction, the CO and CH₄ yields under the condition of 5 wt% methanol coupled with K₂CO₃ reached 2.24-fold and 3.14-fold of the corresponding theoretical values, respectively. Based on the complementary functions of methanol and K₂CO₃, a two-stage regulation strategy was proposed. Specifically, 2.5 wt% methanol was adopted for the aromatic structure pre-cleavage, and 5.0 wt% K₂CO₃ was subsequently added for catalytic gasification. This strategy provided new insights into overcoming the char formation bottleneck during coal SCWG. Full article

Direct coal liquefaction (DCL) is a critical approach to clean and efficient coal utilization. With international energy supplies becoming increasingly unstable due to geopolitical conflicts, the conversion of coal-to-liquid technology plays critical roles in securing energy safety. Inorganic elements in coal are highly variable in content and modes of occurrence. In particular, the modes of occurrence of each element largely determine their migration and transformation behavior during liquefaction, which in turn directly affects products distribution, oil quality, process stability and environmental risks. This paper summarizes the modes of occurrence of major mineral elements (Al, Si, Fe and alkali and alkaline earth metals (AAEMs)) and hazardous trace elements (Hg, As, Pb, Cd and Cr) in low-rank coals, and then discusses their redistribution and speciation evolution during liquefaction. Inorganic elements and minerals exert distinct effects during coal liquefaction. Iron (Fe), cobalt (Co), and nickel (Ni) generally promote hydrogenation and bond cleavage, whereas AAEMs inhibit liquefaction by enhancing radical cross-linking. Pyrite facilitates hydrogen transfer and hydrocracking, while clay minerals may promote condensation and coke formation. For toxic trace elements, mercury (Hg) generally exhibits high volatility and is readily released into the gas phase. Arsenic (As) and cadmium (Cd) show more complex transformation behaviors governed by their associations with sulfides, organic matter, and mineral phases. Lead (Pb) and chromium (Cr) mostly remain in the solid residue due to their low volatility and strong associations with silicates. Overall, this review highlights the importance of the modes of occurrence of inorganic elements in process optimization and environmental risk management in DCL. Full article

Liquid hydrogen offers high gravimetric energy density for low-carbon aviation, but its cryogenic storage imposes stringent geometric, structural, and thermal constraints. This study develops an integrated preliminary design framework for a non-integral liquid-hydrogen tank for a regional aircraft retrofit. Fuel demand for a representative 300-nautical-mile (NM) mission was converted into the required storage volume, followed by parametric geometry definition, material selection, finite-element structural analysis, and steady-state thermal analysis. A circular cylindrical tank with hemispherical heads was selected, providing an internal volume of 4.96 m³, a diameter of 1.56 m, and a total length of 3.12 m. Under an internal pressure of 1 MPa, the symmetric 32-ply T700/epoxy overwrap achieved a minimum ply safety factor of 3.2104. The Al 2219-T87 liner reached a maximum von Mises stress of 306.66 MPa and a minimum safety factor of 1.1837, making it the governing structural component. The predicted heat leak was 14.832 W, corresponding to a boil-off rate of 2.88 kg/day (0.912%/day). The tank mass was 318.9 kg, and the estimated system gravimetric index was 45.2–47.4%. These results support the preliminary feasibility of the proposed configuration and identify liner optimisation and boss-region insulation as priorities for further development. Full article

Pecan (Carya illinoinensis) is an edible nut rich in phytochemicals with potential health-promoting properties; however, the bioactive constituents responsible for its neuroprotective effects remain insufficiently characterized. This study aimed to identify bioactive constituents from pecan through bioactivity-guided fractionation and to evaluate the protective effects of pecan extract and the identified compound against oxidative stress and amyloid beta (Aβ)_1–42-induced cognitive impairment. Pecan ethanolic extract exhibited antioxidant and cytoprotective activities in PC12 cells exposed to hydrogen peroxide-induced oxidative stress. Sequential liquid–liquid fractionation, silica gel open-column chromatography, and preparative thin-layer chromatography, coupled with repeated bioactivity screening, progressively tracked the active fractions and led to the identification of ethyl gallate as a bioactive constituent of pecan extract by high-performance liquid chromatography and gas chromatography–mass spectrometry. The biological relevance of these findings was further evaluated in Aβ_1–42-injected male mice. Dietary administration of pecan extract significantly improved spontaneous alternation performance in the Y-maze test, whereas ethyl gallate improved Y-maze performance and memory retention in the passive avoidance test, without apparent systemic toxicity under the experimental conditions. Although brain malondialdehyde levels showed a numerical decrease following ethyl gallate administration, the differences were not statistically significant. Collectively, these findings demonstrate the bioactivity-guided linkage of ethyl gallate to an active pecan fraction and provide preclinical evidence supporting further investigation of pecan-derived bioactives as food-derived functional ingredients relevant to cognitive health. Full article

Hydrogen storage and transportation technologies based on liquid organic hydrogen carriers (LOHCs) are of high research interest. The next generation of LOHCs with a higher hydrogen capacity and lower dehydrogenation temperature is required, and the decahydroquinoline/quinoline (DHQ/Q) system is among promising LOHCs. The catalysts comprising palladium nanoparticles supported on the synthesized high-surface area materials (CeO₂, CeO₂-ZrO₂ mixed oxide, and Ce_0.75Zr_0.25O₂), as well as reverse CeO₂/Pd/oxide catalysts were tested in solvent-free dehydrogenation of DHQ at a high DHQ:Pd molar ratio, with DHQ being investigated as a hydrogen-storage source. The oxide-supported Pd nanoparticles were synthesized via the deposition–precipitation of Pd poly-hydroxo complexes, while a redox method was used to prepare the reverse catalysts. The highest hydrogen yields of 45% and 55% with the DHQ conversions of 61% and 76% at molar ratios DHQ:Pd of 1000 and 500, respectively, have been reached over the Pd/Ce_0.75Zr_0.25O₂ catalyst at 220 °C, which results in hydrogen production exceeding that of other known catalysts studied in solvent-free DHQ dehydrogenation. The challenges and prospects for further catalyst development are discussed. Full article

Deer Horn Glue is rich in collagen- and tissue-derived proteins, but the link between its experimentally observed proteome, the theoretical peptide sequence space derived from that proteome, and bone-related molecular targets remains poorly defined. This study established a proteomics-guided multiscale computational workflow to prioritize putative receptor activator of nuclear factor-κB ligand (RANKL)-binding peptide candidates generated from proteins identified in one Deer Horn Glue sample. The Deer Horn Glue proteome was characterized by liquid chromatography–tandem mass spectrometry (LC-MS/MS). Experimentally identified proteins were subjected to in silico tryptic digestion and stepwise activity, safety, and physicochemical screening. All 49 retained candidates underwent global and interface-focused docking. Five prioritized peptides were examined by AlphaFold 3, three independently seeded 200 ns molecular dynamics simulations per complex, entropy-omitted molecular mechanics/generalized Born surface area (MM/GBSA) analysis, residue decomposition, and locally relaxed computational alanine substitution analysis. Proteomic analysis retained 707 target protein groups and generated 24,575 nonredundant theoretical peptide sequences. Stepwise screening retained 49 candidates. Global and interface-focused docking rankings showed modest agreement, and the expanded interface analysis identified additional candidates while retaining GASLQDWDFGK as the top-ranked sequence. Across three independent simulations, GASLQDWDFGK showed consistently low peptide root-mean-square deviation (RMSD), whereas HEFSVDMTCEGCSNAVTR formed the largest mean number of interfacial hydrogen bonds. Their entropy-omitted MM/GBSA estimates were generally the most favorable, although the order varied among simulations. Locally relaxed alanine substitutions highlighted reproducible energy-sensitive positions for experimental testing. By linking an experimentally observed Deer Horn Glue proteome to multiscale structural analysis, this workflow provides a traceable and reproducible strategy for prioritizing testable peptide–RANKL interaction hypotheses. The five candidates remain theoretical products of in silico digestion and require targeted detection, direct binding, and functional validation. Full article

Compared to conventional fuels, hydrogen fuel offers advantages such as high specific heat capacity, low boiling point, and zero carbon emissions, demonstrating significant potential for green energy conservation and sustainable development in the aviation field. This paper reviewed the latest advances, technical challenges, research hotspots, and future development directions related to the response and regulation of various components within the hydrogen transportation and thermal management systems for aeroengines, filling a gap in the existing literature. (1) As to the fuel of aeroengines, the heat exchanger efficiency of the heat exchanger employed for intercooling while utilizing hydrogen fuel can reach 10.63 times that of kerosene, and the turbine inlet temperature is significantly reduced under sea-level takeoff conditions. Under high-altitude supersonic flight conditions, its specific fuel consumption is approximately 0.33–0.40 times that of kerosene. However, aeroengines also confront challenges such as the requirement for high-efficiency thermal insulation and the control of cold energy losses. (2) When the pressure regulation accuracy of hydrogen storage containers, hydrogen supply stability, and thermal management coordination are ensured, the fuel weight index can be optimized to 0.62 during hydrogen transportation, significantly reducing the impact of the hydrogen storage system on the payload capacity of aircraft models. Nevertheless, crucial components involved in hydrogen transportation, such as cryogenic liquid hydrogen tanks, are vulnerable to significant temperature fluctuations, which can cause pressure oscillations, response delays, and seal failures, thereby affecting the stability of the hydrogen fuel supply. (3) In the thermal management system of hydrogen-fueled aeroengines, the fuel consumption and transportation cost of the engine compared with the unoptimized baseline system are reduced by 14.54% and 11.74% through regulating important component parameters such as heat exchanger power. However, the thermal management system confronts challenges during the heat exchange among hydrogen fuel, high-temperature airflow, and residual heat, including strong coupling among multiple components and insufficient real-time sensing capability for dynamic thermal loads. Future development should shift from “passive adaptation” to “active regulation and control,” aiming to achieve dynamic decoupling of temperature, pressure, and stress fields under strongly coupled multi-heat source operating conditions, along with coordinated regulation and matching of multi-component dynamic responses. Full article

The development of sustainable and efficient sample-preparation strategies remains a key challenge in analytical workflows for plant-derived bioactive compounds. In this study, choline chloride (ChCl)-based natural deep eutectic solvents (NADES) were systematically investigated as green extraction media and combined with chemical and enzyme assays to identify the bioactive effect of phenolic compounds from Bellevalia dubia, an understudied Mediterranean plant. A design of experiments approach was applied to evaluate the influence of hydrogen bond donors (lactic, malic, and citric acid) and their molar ratios on extraction performance. Among the tested systems, the ChCl–malic acid (MA) mixture at a molar ratio of 1:2.5 (precisely 1:2.47) was identified as the best overall solution according to the desirability approach, which integrated both phytochemical and enzyme-inhibitory responses. This system also showed strong enzyme-inhibitory effects compared to conventional extractants (water and 80% methanol). To identify the extract composition, a suspect screening workflow was applied based on ultra-high-performance liquid chromatography hybrid quadrupole Orbitrap mass spectrometry (UHPLC–q-Orbitrap-MS). Twenty-one compounds were detected and annotated, mainly belonging to the flavonoid class. Principal component analysis (PCA) showed that ChCl-MA extracts were discriminated, particularly at molar ratio 1:2.5, from the rest, indicating a distinct chemical and bioactivity profile. PCA further suggested a possible association of the ChCl-MA 1:2.5 system with vitexin and AChE inhibition, which requires further investigation. Overall, the proposed NADES-based approach offers a tunable, promising, and potentially more sustainable alternative for the extraction of bioactive compounds from plant-based sources. Full article