Search Results (2,630)

Background/Objectives: Physical activity (PA) and energy intake (EI) are central targets of community initiatives to reduce the prevalence of childhood obesity. The general effects of PA and EI in influencing energy balance and body composition are clear. However, the independent impacts of PA and EI on the adiposity of children growing up amidst westernized lifestyles are inconclusive, as few studies have employed sufficiently robust methodology to provide solid independent associative data. Methods: We carried out a systematic review of the research addressing the independent associations of adiposity with each of PA and EI in free-living town or city-dwelling children and adolescents. Acceptable publications included objective measures of fat mass and PA, best standard practice EI assessments, and appropriate statistical modeling. Results: Of approximately 700 publications explored, only four satisfied all the pre-set methodological standards. All four studies involved predominantly White participants from westernized cities and had the same outcomes. Adiposity was strongly independently and negatively related to PA, but there was no evidence of any independent relationship between adiposity and EI. Potential misreporting was considered, especially under-reporting by participants with greater adiposity, butpost-hoc assessments were unable to find any evidence that this influenced the outcomes. Conclusions: In general, children with higher adiposity consumed no more food and beverage energy than their leaner counterparts, but they were less active. However, despite some support for the validity of the commonly used and validated EI assessments, their subjective nature raises the possibility that inaccuracy masked relationships. Additional well-designed research is needed, and notwithstanding the vital role that sound nutrition plays in the healthy development of our youth, the consistency of outcomes of the well-executed studies in this review suggests that campaigns targeting youth obesity would benefit from strategies focusing strongly on increasing PA. Full article

The increasing amount of carbon dioxide (CO₂) in the atmosphere is the main factor contributing to climate change. Recent studies have determined that simply reducing emissions is insufficient to restore the Earth’s atmospheric system—negative emissions are therefore necessary. Current carbon (i.e., CO₂) capture technologies use thermal or pressure swings. These approaches suffer from low energy efficiency, high cost, and geographic constraints. Electro-swing chemistry-based carbon capture has emerged as a promising potential solution to these challenges. However, strong CO₂-binding sorbents, not susceptible to oxygen interference, remain elusive. In this study, three electron-deficient quinones were designed and tested as CO₂ capture molecular sorbents. Cyclic voltammetry (CV) on these novel quinones reveals that 2,3-dicyano-1,4-benzoquinone (DBQ) has a second reduction potential positive of that of oxygen reduction. Moreover, this sorbent binds to CO₂ with a free energy ΔG_bind of −5.39 kcal/mol when activated by electrochemical reduction. These results suggest that DBQ may be a sorbent candidate that can capture >70% of CO₂ in the current atmosphere using electro-swing chemistry without the interference of oxygen in the air. This novel sorbent can be further developed for large-scale carbon capture and combating global warming and its associated impacts. Full article

This work develops a novel Ni-Co nanoparticles coupled with Ni₃S₂ and Co₉S₈ phases on nickel foam (denoted as Ni-Co NPS@Ni₃S₂/Co₉S₈/NF) hybrid structure material as a bifunctional water electrolysis catalyst. The self-assembly Ni-Co alloy phases enhance electrical conductivity, while the synergistic interactions among the three components (Ni-Co, Ni₃S₂ and Co₉S₈) optimize the lattice parameters and electronic environment for boosting both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). The catalyst achieves low overpotentials of 106 mV for HER and 185 mV for OER at 10 mA·cm⁻² in 1M KOH, along with a very low charge-transfer resistance. Density functional theory (DFT) calculations reveal that the multi-component interaction narrows the band gap and optimizes the hydrogen adsorption free energy (ΔG_H*) as well as the adsorption free energies of OER intermediates (ΔG_OH*). This work identifies the hybrid structure as the key to the enhanced activity and offers a promising strategy for designing efficient nickel–cobalt-based electrocatalysts. Full article

Plant–microbe interactions exert a significant influence on host stress responses; however, the molecular mechanisms underlying these effects remain inadequately understood. In this study, we characterize FaMAN8, an α-mannosidase from Fragaria × ananassa, to explore its role in adaptation to heat waves and water deficit, as well as its modulation by fungal endophytes. Transcriptomic analysis identified FaMAN8 as the sole α-mannosidase isoform highly conserved across reported sequences, with root-specific induction under conditions of heat stress, deficient irrigation, and endophytic colonization. Structural modeling revealed that FaMAN8 exhibits the canonical domain organization of glycoside hydrolase family 38 (GH38) enzymes, featuring a conserved catalytic architecture and metal-binding site. Molecular docking and dynamics simulations with the Man₃GlcNAc₂ ligand indicated a stable binding pocket involving key catalytic residues and strong electrostatic complementarity. MM-GBSA and free energy landscape analyses further supported the thermodynamic stability of the protein–ligand complex. Cavity analysis revealed a larger active site in FaMAN8 compared to its homolog JbMAN, suggesting broader substrate accommodation. Collectively, these findings identify FaMAN8 as a stress-responsive glycosidase potentially involved in glycan remodeling during beneficial root–fungus interactions. This work provides molecular insights into plant–microbe symbiosis and lays the groundwork for microbiome-informed strategies to enhance crop stress resilience. Full article

Driven by 5G/6G and the Internet of Things (IoT), wireless sensor networks (WSNs) are confronted with core challenges such as limited energy constraints, unbalanced resource allocation, and security vulnerabilities. To address these, WSNs are integrated with cognitive radio networks (CRNs) to alleviate spectrum scarcity, and reconfigurable intelligent surfaces (RIS) are adopted to enhance performance, but traditional passive RIS suffers from “double fading” (signal path loss from transmitter to RIS and RIS to receiver), which undermines WSNs’ energy efficiency and the physical layer security (PLS) (e.g., secrecy rate, SR) of primary users (PUs) in CRNs. This study leverages symmetry to develop an active RIS framework for WSN-integrated CRNs, constructing a tripartite collaborative model where symmetric beamforming and resource allocation improve WSN connectivity, reduce energy consumption, and strengthen PLS. Specifically, three symmetry types—resource allocation symmetry, beamforming structure symmetry, and RIS reflection matrix symmetry—are formalized mathematically. These symmetries reduce the degrees of freedom in optimization (e.g., cutting precoding complexity by ~50%) and enhance the directionality of green interference, while ensuring balanced resource use for WSN nodes. The core objective is to minimize total transmit power while satisfying constraints of PU SR, secondary user (SU) quality-of-service (QoS), and PU interference temperature, achieved by converting non-convex SR constraints into solvable second-order cone (SOC) forms and using an alternating optimization algorithm to iteratively refine CBS/PBS precoding matrices and active RIS reflection matrices, with active RIS generating directional “green interference” to suppress eavesdroppers without artificial noise, avoiding redundant energy use. Simulations validate its adaptability to WSN scenarios: 50% lower transmit power than RIS-free schemes (with four CBS antennas), 37.5–40% power savings as active RIS elements increase to 60, and a 40% lower power growth slope in multi-user WSN scenarios, providing a symmetry-aided, low-power solution for secure and efficient WSN-integrated CRNs to advance intelligent WSNs. Full article

Background/Objectives: Testosterone and cortisol are key regulators of metabolic, psychological, and physiological responses to environmental and lifestyle factors. This study aimed to analyze the relationship between free testosterone and cortisol concentrations and dietary patterns, stress levels, sleep quality, physical activity, and body composition in healthy young men (aged 18–35 years). Methods: This study included 40 volunteers who met our inclusion criteria. They underwent anthropometric measurements, body composition analysis, and biochemical determination of serum free testosterone and cortisol concentrations. Additionally, participants completed a set of validated questionnaires: a questionnaire regarding the frequency of consumption of specific foods and stimulants, a 3-day food diary, the PSS-10, the Holmes and Rahe Scale, the PSQI, and the Baecke Physical Activity Questionnaire. Results: Free testosterone concentration in blood was negatively correlated with body fat content and positively correlated with the percentage of energy, protein, fat, sodium, and folic acid requirements. Morning blood cortisol levels negatively correlated with body weight and height. Higher intakes of cholesterol, folic acid, and vitamin A resulted in statistically significant reductions in cortisol levels. A significant correlation was identified between poor sleep quality and low cortisol levels, particularly among men aged < 26 years. A positive correlation was also found between leisure-time physical activity and testosterone levels, particularly in the older group. Furthermore, a higher body weight and greater muscle mass were correlated with lower cortisol levels. Conclusions: These results provide a starting point for further research on neuroendocrine mechanisms in active individuals exposed to environmental stress. Full article

This research assesses the bioenergy potential of date palm branch (DPB) waste, aligning with Saudi Arabia’s Vision 2030 energy and environmental goals. The study uses reaction modeling, thermokinetics, a k-nearest neighbors (KNN) machine learning approach, and techno-economic assessments. Experimental characterizations employing FTIR, SEM, and both proximate and ultimate analysis of pulverized DPB biomass reveal its lignocellulosic nature and compositional characteristics. Thermogravimetric analysis (TGA) of the material, tested between 25 and 1000 °C at heating rates of 7.5 to 60 °C per minute, revealed that the main thermal breakdown occurred from 200 to 530 °C, and was caused by the decomposition of hemicellulose and cellulose. Criado master plot analysis of the material’s thermal decomposition indicated the R3 contracting cylinder model was the most suitable reaction mechanism. The Jander [D3] and Ginstling–Brounshtein [D4] diffusion models were also good fits. The kinetic analysis showed that various model-free approaches, including FWO, KAS, STK, and FR, yielded comparable activation energy values for the hemicellulose and cellulose components, with the results clustering between approximately 98.43 and 109.30 kJ/mol. The application of the KNN machine learning technique in this study yielded accurate predictions ($R^2~0.975$) of the TGA traces following rigorous modeling that involved hyperparameter optimization and testing of the trained model on 20% unseen data. Through a global sensitivity analysis, the degradation temperature for DPB’s thermal devolatilization was identified as the key parameter controlling the pyrolysis process. The techno-economic assessments of the pyrolysis operation indicate that it is a viable, financially rewarding, and environmentally friendly process, offering valuable insights for policymakers, environmental engineers, and energy professionals toward promoting sustainable waste management and a circular economy. Full article

Free trading of distributed energy resources (DERs) is an effective way to enhance local renewable consumption and user-side economic efficiency. Yet unrestricted sharing may threaten operational security. To address this, this paper proposes a voltage-constrained, differentiated resource-sharing framework for active distribution networks (ADNs). The framework maximizes users’ economic benefits and renewable absorption while keeping system voltages within safe limits. A local energy market with prosumers and the distribution network operator (DNO) is established. Prosumers optimize trading decisions considering transaction costs, wheeling charges, and operational costs. Based on this, a generalized Nash bargaining model is developed with two sub-problems: cost optimization under voltage constraints and payment negotiation. The DNO verifies prosumer decisions to ensure system constraints are satisfied. This paper quantifies prosumer heterogeneity by integrating market participation and voltage regulation contributions, and proposes a differentiated bargaining model to improve fairness and efficiency in DER trading. Finally, an ADMM-based distributed algorithm achieves market clearing under AC power flow constraints. Case studies on modified IEEE 33-bus and 123-bus systems validate the method’s effectiveness, the allocation of benefits between producers and consumers is more equitable, and the costs for highly engaged producers and consumers can be reduced by 46.75%. Full article

The development of hydrogen energy is advancing rapidly, while the progress of hydrogen sensors has been relatively lagging behind and cannot meet the stringent performance requirements of hydrogen energy applications. WO₃ has attracted significant attention due to its highly complementary optical and electrical responses to hydrogen. In this study, hydrogen-sensitive WO₃ thin films characterized by vertically aligned crystallites were fabricated by modulating the substrate temperature and oxygen pressure during pulsed laser deposition. Building upon this foundation, a comprehensive investigation into surface modification strategies for enhancing sensitivity was undertaken. The surface modifications encompassed eight distinct metals and four different metal oxides. Among the metal-modified samples, palladium (Pd) Pd exhibited a markedly enhanced electrical response, defined as the ratio of the resistance in hydrogen-free air to that in hydrogen, of 1022, corresponding to ~45 times higher than the value of 22.4 achieved for Pt-modified films and 120 times higher than the value of 8.4 for Au-modified films. In addition, Pd/WO₃ films showed a measurable optical transmittance change of 9.7%, while all other metal-modified samples exhibited negligible optical responses (<1%). This enhancement is attributable to the catalytic and electronic sensitisation effects of Pd. Conversely, metals such as platinum (Pt), gold (Au), and silver (Ag) elicited negligible optical responses, suggesting minimal catalytic activity. The electrical response in these cases was primarily governed by electronic sensitization effects related to the work function of the metal, with higher work function values correlating with more pronounced sensitization. Regarding metal oxide modifications, the sensitization effect was more substantial when the disparity in work function between the oxide and WO₃ was greater, and this enhancement was found to be independent of the charge carrier type of the modifying oxide. These results offer significant insights into the design principles underlying high-performance WO₃-based hydrogen sensors and underscore the pivotal influence of surface modification in governing their sensing characteristics. Full article

The escalating crisis of antibiotic resistance, particularly concerning foodborne pathogens such as Staphylococcus aureus and its biofilm contamination, has emerged as a major global challenge to food safety and public health. Biofilm formation significantly enhances the pathogen’s resistance to environmental stresses and disinfectants, underscoring the urgent need for novel antimicrobial agents. In this study, we isolated Bacillus strain B673 from the saline–alkali environment of Xinjiang, conducted whole-genome sequencing, and applied antiSMASH analysis to identify ribosomally synthesized and post-translationally modified peptide (RiPP) gene clusters. By integrating an LSTM-Attention-BERT deep learning framework, we screened and predicted nine novel antimicrobial peptide sequences. Using a SUMO-tag fusion tandem strategy, we achieved efficient soluble expression in an E. coli system, and the purified products exhibited remarkable inhibitory activity against Staphylococcus aureus (MIC = 3.13 μg/mL), with inhibition zones larger than those of the positive control. Molecular docking and dynamic simulations demonstrated that the peptides can stably bind to MurE, a key enzyme in cell wall synthesis, with negative binding free energy, suggesting an antibacterial mechanism via MurE inhibition. This study provides promising candidate molecules for the development of anti-drug-resistant agents and establishes an integrated research framework for antimicrobial peptides, spanning gene mining, intelligent screening, efficient expression, and mechanistic elucidation. Full article

In this study, a novel activated carbon (AC) (AC-Ba(OH)₂) was synthesized through a three-step process (including hydrothermal carbonization (at 250 °C), alkali activation by Ba(OH)₂, and pyrolysis (at 850 °C)), from Plane tree fruits (PTFs). By using various experimental methods for material characterization, it was established that the resulting material possesses a variety of oxygen functional groups, rich in alkaline earth oxides (BaO/CaO), SiO₂, consisting of graphitized carbon with graphene structures. A detailed kinetic and thermodynamic analysis of AC-Ba(OH)₂ thermal restoring was also carried out. Thermodynamic analysis revealed the existence of a true thermodynamic compensation effect (TCE) during restoration. Restoration was controlled by entropy, where experimental temperatures are above the iso-entropic temperature, i.e., the temperature where contributions of enthalpy and entropy to activation free energy are balanced. Kinetic modeling has shown that restoration allows carbon material to be significantly modified by removing oxygen-containing groups via diffusion, changing active sites on the surface, and preparing material for catalyst support. CaO and SiO₂ act as catalysts, while BaO alters graphene surface properties. Isothermal prediction tests have shown an extremely high long-term stability of modified AC-Ba(OH)₂, supporting an elevated activity, selectivity, and lifetime, as well. The restoring process resulted in an energy consumption of 0.762 kWh, which is equivalent to the reactivation of AC with a lower specific surface area. Manufactured AC and its thermally modified counterpart can be used as both a catalyst support and catalyst for reforming processes, such as methanol synthesis, biogas purification, and dry reforming of methane. Full article

This study reports the design of N- and S-doped ordered mesoporous carbon hollow spheres (OMCHS) as metal-free electrocatalysts for the oxygen reduction reaction (ORR) in alkaline media. Three electrocatalysts were synthesized using molecular precursors: (i) 2-thiophenemethanol (S-OMCHS), (ii) 2-pyridinecarboxaldehyde/2-thiophenemethanol (N1-S-OMCHS), and (iii) pyrrole/2-thiophenemethanol (N2-S-OMCHS). Among them, S-OMCHS exhibited the best activity (E_onset = 0.88 V, E_½ = 0.81 V, n ≈ 3.95), surpassing both co-doped analogs. After conducting an accelerated degradation test (ADT), S-OMCHS and N1-S-OMCHS showed improved catalytic behavior and outstanding long-term stability. Surface analysis confirmed that performance evolution correlates with heteroatom reorganization: S-OMCHS retained and regenerated thiophene-S and C=O/quinone species, while N1-S-OMCHS converted N-quaternary into N-pyridinic/pyrrolic, both enhancing O₂ adsorption and *OOH reduction through synergistic spin–charge coupling. Conversely, oxidation of N and loss of thiophene-S in N2-S-OMCHS led to partial deactivation. These results establish a direct link between surface chemistry evolution and electrocatalytic durability, demonstrating that controlled heteroatom doping stabilizes active sites and sustains the four-electron ORR pathway. The approach provides a rational design framework for next-generation, metal-free carbon electrocatalysts in alkaline fuel cells and energy conversion technologies. Full article

Aluminum/lithium (Al/Li) alloy is a promising energetic material for solid composite propellants. The bonding structure, topological shape, density, cohesive energy, and mechanical and diffusion properties of the Al/Li alloy bulks and oxidation shells are calculated systematically using the large-scale force-field molecular dynamics simulations together with the ab initio quantum chemistry calculations. Theoretical predicted structures and dynamic properties for various crystalline and amorphous reference compounds are compared with the available experimental data to validate the force-field simulations. The dependence of the structures and properties on the Li contents ranging from 2 to 50 wt% is clarified. It is revealed that both Al and Li atoms are resident in the same Al or Li environment in the Al/Li alloys. The presence of the crystalline δ’-Al₃Li and β-AlLi phases in the Al/Li alloys is rationalized in terms of the coordination of Al/Li and the thermodynamic free energy of Li substitution. A homogenous six-coordinated Al/Li alloy could be generated with a Li content of 20 wt%. Young’s moduli of the alloys are improved via the low Li addition due to the anisotropic effect. The Al/Li/O oxidation shell is less dense than the amorphous alumina but the densities of oxides are generally higher than those of the corresponding Al/Li alloys. As the Li content increases, the Al/Li/O oxides form the ordered four-coordinated AlO₄ passages together with the under-coordinated Li-O units, leading to considerably deteriorated mechanical performance and efficient Li diffusion with an activation energy of about 20 kJ/mol. The present work provides a deep understanding of the Al/Li alloys and Al/Li/O oxides in terms of performance and exposure stability. Full article

In the process of decarbonizing electricity generation, renewable energy sources are actively being integrated into traditional power systems. As a result, the inertia of the energy system is reduced, and the speed of transition processes is accelerated. This can lead to instability under small disturbances. This necessitates changing traditional approaches to implementing algorithms for emergency control automation. The paper proposes a methodology to solve the problem of small-signal stability analysis in low-inertia energy systems. The task of the small-signal stability analysis problem is reduced to multi-class classification problems. The proposed methodology can be divided into two main parts: selecting the most informative input features and classifying control actions. The IEEE24 mathematical model of the power system serves as a data source. Measurements from this model are received via phasor measurement units. Among the feature selection algorithms considered, the Random Forest algorithm proved to be the most effective. In terms of efficiency in solving the control action selection problem, the LightGBM algorithm proved dominant. Its accuracy in noise-free data was 98%. With 20 dB of data noise, the algorithm’s accuracy decreased slightly: 97%. The algorithm’s time delay was only 0.07 ms. Full article

Background/Objectives: Dihydroquercetin, known for its broad biological activities, is a key component in dietary supplements and functional foods. This study aims to identify its novel pure solid forms, advancing understanding of its physicochemical properties and polymorphism. Methods: Systematic screening, preparation, and characterization efforts identified five solvates: dihydroquercetin monohydrate (1:1, S1 and S2), sesquihydrate (1:1.5, S3), dihydrate (1:2, S4), and ACN solvate (1:1, S5), along with one solvent-free phase (S6). Results: The crystal structures of the five solvates were successfully elucidated for the first time. A comprehensive suite of techniques, including single-crystal and powder X-ray diffraction, DSC, TG, and FT-IR, were employed to characterize the solvates and polymorphs. Hirshfeld surface analysis, void map analysis, intermolecular energy calculations, and energy framework methods were utilized to investigate the characteristics of the solvates. The crystal transformation relationships among these forms were also explored. Conclusions: Results demonstrate that O···H interactions dominate the intermolecular forces, accounting for over 35% of the total interactions. Full article