Search Results (11,693)

Cooperative searches by unmanned aerial vehicles (UAVs) have wide applications in urban environments. However, the dense obstacles and limited communication networks in urban settings often lead to repeated searches and inefficient information sharing among UAVs. To address these challenges, this article proposes a novel cooperative strategy named the Asynchronous Collaborative Hybrid Architecture (ACHA), which is tailored for urban flight. Specifically, a digital pheromone mechanism is devised to create artificial potential field to guide UAVs’ search efficiently within local communication constraints. Moreover, UAVs switch between the dual decision mode, namely Chain-Following Mode (CFM) and Tree Expansion Mode (TEM) based on the urban environmental topology. When UAVs arrive at a bifurcation node, the TEM is activated, asynchronously triggering the Collaborative-aware Pruning Search Tree (CPT) algorithm to generate subsequent paths, after which they switch back to CFM. Theoretically, it is demonstrated that the collaborative-aware pruning scheme can avoid the “cooperative benefit trap”, where there is a significant divergence between the actual and predicted cooperative benefits. The simulation results confirm that the proposed method outperforms existing approaches in terms of cooperative search accuracy, collision risk and convergence speed in complex urban search scenarios. Full article

PrFeTiO₃ perovskite composite was synthesized, and its structural, morphological, chemical, and optical properties were comprehensively characterized. X-ray diffraction (XRD) and a selected area electron diffraction (SAED) confirm the formation of an orthorhombic distorted perovskite phase with no secondary impurities. Transmission electron microscope (TEM) observations show aggregated nanocrystalline domains, while EDS mapping reveals homogeneous cation distribution (Pr, Fe, Ti, O), confirming successful incorporation of Fe and Ti into the perovskite lattice. X-ray photoelectron spectroscopy (XPS) analysis identifies Pr³⁺, Fe³⁺, and Ti⁴⁺ as the dominant oxidation states, supporting charge-compensated B-site substitution. Optical analysis reveals a bandgap of ~2.0 eV, significantly narrower than pristine titanates, indicating enhanced visible-light absorption. This multi-modal characterization verifies the successful formation of PrFeTiO₃ and highlights its potential as a visible-light-active photocatalyst. Although PrTiO₃ showed little reactivity to visible light, PrFeTiO₃ showed excellent efficiency in visible light photocatalytic reactions. PrFeTiO₃ showed more than 20 times better performance than PrTiO₃ in the photodegradation of methylene blue in the liquid phase and formaldehyde in the gas phase. Furthermore, PrFeTiO₃ showed more than 95% superior bactericidal activity against the pathogenic bacterium Staphylococcus aureus than PrTiO₃. Its high photocatalytic efficiency can be attributed to its strong photosensitivity to visible light and small band gap energy. Full article

This work investigates the reciprocal adhesion of Polybenzoxazole (PBO) and silicon nitride (SiN) with a focus on the combined effects of surface chemistry and environmental conditions, i.e., temperature (T) and relative humidity (RH). A set of six samples, including standard and silicon-rich SiN substrates treated with oxygen (O₂) or carbon tetrafluoride (CF₄) plasma, was fabricated and characterized by AFM, XPS, and TEM/EDX to quantify surface roughness and interfacial chemical modifications. Adhesion with PBO was then assessed through nanoindentation both in situ, during ambient control, and ex situ, after aging in a climatic chamber. Compared to PBO adhesion with as-deposited standard and silicon-rich SiN, O₂ plasma treatment was shown to improve adhesion by 13% and 24%, respectively, whereas CF₄ plasma treatment was still beneficial but more limited, improving adhesion by 8% for both substrates. The different effects were ascribed to the formation of a surface oxide layer after O₂ plasma, enhancing chemical affinity and substantially equalizing the adhesion on the two SiN substrates, while CF₄ plasma was impacting adhesion by reducing the substrates’ activity and, thus, increasing the efficiency of the PBO curing procedure. Notably, the adhesion loss with increasing dew point of the ambient (dependent on temperature and relative humidity) was observed across all samples regardless of surface treatment, reinforcing the critical role of absorbed moisture on polymeric film adhesion. However, this trend was observed for all samples only for in situ testing, with a loss of 25% in the critical load of delamination for the most critical environment, while ex situ tests showed a marked recovery of adhesion properties, leading to measurements no longer reflecting the actual state of the samples inside the altered environment. The results presented in this paper highlight the effect of substrate preparation on the adhesion of an organic compound and a substantial difference in environmental control methods for adhesion testing, providing an alternative approach to classical aging treatments and subsequent characterization for qualifying polymer/inorganic interfaces exposed to stressful operational conditions. Full article

Post-harvest deterioration in strawberries is an urgent and critical issue that requires significant attention. Glycerol monolaurate (GML), a broad-spectrum food-grade antimicrobial agent, faces limited applicability due to its poor water solubility. In this study, a confined encapsulation strategy was employed to encapsulate GML within hydroxypropyl-γ-cyclodextrin (HPγCD), which improved the physicochemical properties of GML and enhanced its stability in the environment. The fiber morphology was observed through scanning electron microscopy (SEM) and transmission electron microscopy (TEM), confirming the presence of a uniform, non-nodular core–shell structure. The Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) validated the successful encapsulation of GML within the cavity of HPγCD. Thermogravimetric analysis (TGA) demonstrated that the thermal stability of the core–shell system was significantly improved. In vitro release followed first-order kinetics (R² = 0.9842), with 79.5% of GML released over 68 h. The DPPH and ABTS assays demonstrated that PLA/GML-HPγCD NF exhibited sustained radical scavenging activity (p < 0.05, ANOVA). Compared to GML-HPγCD NF, PLA/GML-HPγCD NF exhibited prolonged antibacterial activity against Escherichia coli and superior antifungal efficacy in strawberry preservation. Meanwhile, PLA/GML-HPγCD NF significantly reduced lesion diameter and weight loss while maintaining hardness, total soluble solids, and vitamin C content over 8 days of storage. In conclusion, these characteristics highlighted the potential of P/G-HPγCD NF as a promising active packaging material for extending the shelf life of perishable fruits. Full article

Bovine mastitis threatens the dairy industry with limited effective therapies. The selenoprotein family offers potential anti-inflammatory interventions, yet the role of Selenoprotein F (SELENOF) remains unclear. This study investigated SELENOF in mitochondrial damage and pyroptosis using clinical mammary biopsies and a Staphylococcus aureus-induced Mammary alveolar cell-type T (MAC-T) cell model. Histology, TEM, immunofluorescence, Western blot, qPCR, RNA-seq, and mitochondrial staining (MitoTracker Red and JC-1) were employed. Mastitic mammary tissue exhibited severe architectural disruption, including focal necrosis with coalescing vacuoles of variable size, extensive epithelial denudation, and interstitial thickening with dense inflammatory infiltrates. At the ultrastructural level, mitochondrial swelling, cristae loss, and plasma membrane rupture were evident. Additionally, these tissue specimens exhibited marked upregulation of inflammatory mediator transcripts, notably IL-1β, IL-6, and TNF-α, alongside heightened abundance of pyroptosis-associated proteins including NOD-like receptor family pyrin domain containing 3 (NLRP3), cleaved caspase-1, and GSDMD-N (Gasdermin D N-terminal domain). RNA-seq identified SELENOF as significantly downregulated. The MAC-T model recapitulated the mitochondrial dysfunction, inflammatory response, and pyroptosis observed in mastitic tissue. SELENOF overexpression restored mitochondrial membrane potential, dampened the output of inflammatory signaling molecules, and suppressed NLRP3-mediated pyroptosis via attenuation of caspase-1/GSDMD-N pathway activation. These findings establish SELENOF as a novel target that mitigates bovine mastitis by preserving mitochondrial homeostasis and suppressing NLRP3-mediated pyroptosis. Full article

Increased air pollution and associated disease prognosis are a serious concern in communities across the socioeconomic spectrum. Past studies have shown that a major component of air pollution, fine particulate matter (PM_2.5), is elevated in majority-Black communities in the US to greater levels than those in majority-White communities, which can potentially contribute to higher rates of respiratory health issues. In this study, we address whether PM_2.5 correlates with increased asthma rates in Durham, North Carolina. We selected monitoring sites in different census tracts within the same zip code with disparate levels of asthma to quantify and characterize PM_2.5 levels. We found that South Durham, which has higher asthma hospitalization rates, has higher average PM_2.5 levels (78.49 µg/m³) than North Durham (26.3 µg/m³). We measured the elemental composition of PM samples using transmission electron microscopy–energy dispersive X-ray spectroscopy (TEM-EDX) and found significant differences in the levels of Na, S, Ca, Mg, Fe, and Ti. Our data suggests that these differences in ambient PM_2.5 could contribute to differences in health outcomes in the two areas. We also discuss these differences in the context of social vulnerability within the two study sites and show that the more vulnerable site (South Durham) experiences higher pollution rates. Full article

In the present manuscript, the influence of reaction time on the hexagonal-to-monoclinic phase transition in hydroxyapatite (HAp) nanofibers synthesized via a low-temperature modified hydrothermal method at 100 °C is investigated. The resulting nanofibers were highly crystalline and stoichiometric, with a Ca/P ratio of approximately 1.67. Comprehensive structural and functional characterization, combining X-ray diffraction with Rietveld refinement, Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, transmission electron microscopy (TEM), and resonance-tracking piezoresponse force microscopy (RT-PFM), was employed to elucidate the role of the non-centrosymmetric monoclinic P2₁/b phase in governing HAp’s structural and piezoelectric properties. The analyses indicated a time-dependent phase evolution from hexagonal (P6₃/m) to monoclinic (P2₁/b), with exclusive formation of the hexagonal phase at 6 h and a clearly dominant monoclinic fraction (73.56%) after 24 h. Nanofibers synthesized for 48 h comprised approximately 98% monoclinic HAp and exhibited elongated morphologies with an average length of 354.82 nm and diameter of 45 nm. RT-PFM measurements confirmed a pronounced piezoelectric response associated with the monoclinic phase, yielding an effective piezoelectric coefficient (d_eff) of 19.85 pm/V. In vitro MTT assays demonstrated that the high monoclinic content did not compromise biocompatibility, as cell viability and cytotoxicity met the requirements of ISO 10993 and ASTM F895 standards. These findings offer new insights into how monoclinic ordering governs the piezoelectric behavior of HAp and suggest a promising strategy for enhancing its performance in biomedical applications. Full article

Palm oil is a major agricultural commodity and an important economic driver in Asia. However, the sustainability and productivity of this crop are constantly threatened by a range of pathogenic fungi, especially Ganoderma boninense. Therefore, this study aimed to develop an eco-friendly hexaconazole-loaded nanoemulsion (Hexa-NE) for effective and targeted fungicide delivery while reducing environmental and health impacts. The optimized Hexa-NE formulation was evaluated for particle size, polydispersity index (PDI), zeta potential, pH, viscosity, and morphology using Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM). Fungicide release, stability, and antifungal activity were conducted to assess the overall efficacy and performance of the formulation. The Hexa-NE exhibited particle size of 105.8 nm, a PDI of 0.358, a zeta potential of −53.53 mV. The formulation remained stable over three months of storage. It also demonstrated favourable physicochemical properties including low viscosity (30.24 mPa·s), low surface tension (23.87 mN/m), and suitable pH (6.14) for foliar application. TEM and SEM analyses confirmed spherical droplets and revealed significant hyphal damage to G. boninense. The antifungal test showed a higher inhibition of 97.1% at 0.1 µM of Hexa-NE as compared to hexaconazole solution which only 40% at the same concentration. Release studies exhibited a sustained release of hexaconazole, which may prolonged fungicidal activity. In conclusion, Hexa-NE showed promising laboratory-scale antifungal performance against G. boninense. These findings support its potential for further investigation as a nanoformulated fungicide for future greenhouse and field evaluations. Full article

Polymeric electrolyte membranes based on a low equivalent-weight Aquivion^® commercial dispersion (D72-25BS; EW = 720 g eq⁻¹, Syensqo) were fabricated using a standardized in-house doctor-blade casting technique for application in proton exchange membrane fuel cells (PEMFCs). The low equivalent-weight (EW) Aquivion^® dispersion is a copolymer of tetrafluoroethylene (TFE) and sulfonyl fluoride vinyl ether (SFVE), commonly referred to as a short-side-chain (SSC) ionomer, which exhibits higher ion-exchange capacity (IEC) and proton conductivity than long-side-chain (LSC) perfluorosulfonic membranes. A home-made 30 wt.% Pt/CeO₂ radical scavenger (denoted syn-scavenger) was synthesized via a colloidal method and incorporated into the Aquivion^® membranes to investigate its mitigating effect on chemical degradation induced by peroxide radicals, a role typically associated with Ce-based scavengers. Particularly, the unique aspects of the Pt/CeO₂ scavenger synthesis could be summarized in the following points: (i) the mild aqueous deposition approach enabling highly dispersed Pt species on CeO₂ without the use of organic ligands; and (ii) the tailored redox interaction between Pt and ceria that enhances radical scavenging activity. Two Aquivion^® membranes (denoted Aqu) containing different syn-scavenger loadings (1.0 and 1.5 wt.%) were prepared and compared with a pristine Aquivion^® membrane and a membrane containing commercial CeO₂ (1.0 wt.%). Physicochemical characterization of the scavenger was performed using transmission electron microscopy (TEM), BET surface area analysis, and X-ray diffraction (XRD). The membranes were characterized by micro-Raman spectroscopy, water uptake and hydration number (λ), IEC, and proton conductivity measurements. To assess membrane stability, exsitu chemical oxidative degradation tests were conducted using Fenton’s reagent. Overall, the membrane containing 1.0 wt.% syn-scavenger emerged as the most promising candidate, exhibiting favourable chemical–physical properties and the lowest reductions in IEC and proton conductivity following the degradation test. Full article

To boost the power and conversion efficiency of a polygonal automobile exhaust thermoelectric generator (AETEG), an innovative protrusion-type disturbance is introduced to the original sickle-shaped fins in this work. A coupled multiphysics field model integrating fluid, thermal, and electrical fields was constructed, a net power framework was formulated, and the protrusion structure parameters of protrusion radius and spacing were optimized. At a flow velocity of 40 m/s and an inlet temperature of 600 K, simulation results reveal that increasing the protrusion radius and protrusion spacing effectively improves the heat capture capability and the overall performance of the AETEG system. Simultaneously, the backpressure inside the heat exchanger increases, accompanied by a decline in temperature uniformity at the hot side of the thermoelectric modules (TEMs). Based on the designed multiple performance metrics, the optimal protrusion configuration is finally set as R = 8 mm, D_tg = 8 mm, and D_hf = 5.5 mm. Compared with the original AETEG system with sickle-shaped fins, the optimized protrusion design enhances the TEMs’ average hot-side temperatures by 5.11%, increases the output power by 42.22%, and improves the net power by 76.48%. Additionally, this optimization results in a 13.44% improvement in conversion efficiency and a 40.65% enhancement in net efficiency. Full article

Hematopoietic stem cell transplant (HSCT) is a curative therapy for acute lymphoblastic leukemia (ALL), but its success is limited by chronic graft-versus-host disease (cGvHD) and disease relapse. A central challenge is uncoupling the graft-versus-leukemia (GvL) effect from cGvHD. Early changes in the bone marrow microenvironment following HSCT may offer a predictive window into these divergent outcomes. We conducted a retrospective, single-center, exploratory study on 14 pediatric ALL HSCT patients. Applying single-cell antibody-sequencing (AbSeq) on archived bone marrow aspirates collected 60–100 days post-HSCT, we evaluated immune patterns associated with the development of cGvHD or ALL relapse after day 114. cGvHD after day 114 was associated with upregulation of the endoplasmic reticulum (ER) stress transcription factor XBP1 in transitional B cell and IgM memory B cell populations, a mincle^highPD1⁻ neutrophil population, and exhausted LAG3⁺ effector memory T cells (T_EM). ALL relapse after day 114 was associated with higher CD22, CD24, and ARG1 expression in M(IL-4)-like macrophages and exhausted TIGIT⁺ T_EM. Results from this exploratory study suggest that marrow immune signatures of B cell ER stress preceding later development of cGvHD and macrophage-mediated immune evasion preceding relapse may potentially be early biomarkers for separating GvL from cGvHD in ALL HSCT. Validation with larger cohorts is warranted. Full article

Scanning electron microscopes (SEMs) are crucial for material characterization. They are highly susceptible to vibration from environmental sources, internal components, and other external factors, which can impair measurement accuracy. Traditional solutions are limited in addressing multi-source vibrations: passive isolation struggles with internal vibrations, while image post-processing cannot fundamentally correct large-amplitude deviations in the electron beam. Therefore, this study proposes a hybrid framework that combines real-time active hardware suppression with post-processing to mitigate vibration-induced distortion in SEM images. Using a self-developed external controller and software, the framework extracts periodic vibration features via FFT, quantifies scan line horizontal offset, and implements real-time inverse offset during imaging to suppress dominant-frequency vibration at the source. An adaptive median filtering algorithm is integrated with a Laplacian edge enhancement algorithm to address residual edge burrs, thereby balancing distortion suppression and detail preservation. Experiments at 100 kx magnifications demonstrate notable correction effects: the peak-to-peak value, edge transition width (ETW), and no-reference image quality (NIQE) score are reduced by 39.4%, 91.7%, and 58.9%, respectively. Consistent correction trends are observed at 50 kx, with periodic vibration distortion essentially eliminated across both magnifications. Furthermore, distortion can be regulated through the phase interaction between dwell time and vibration period, making the strategy universally applicable and easy to implement. Without the need for vibration source localization, the framework is compatible with various types of vibration interference. It provides a solution for mitigating vibration impacts in high-magnification, precise characterization of SEMs and offers a reference for anti-vibration optimization of other microscopic techniques, such as transmission electron microscopy (TEM) and atomic force microscopy (AFM). Full article

The CO₂ hydrogenation reaction is a cornerstone reaction in catalytic conversion technologies, with Ru/TiO₂ catalysts being amongst the most active and selective for CH₄ formation. A key factor in the preparation of such catalysts is the choice of chemical precursor for Ru impregnation, as it can substantially influence the physicochemical properties and catalytic performance. In this study, we deliberately employ a simple incipient wetness impregnation method to isolate the effect of the Ru precursor itself, using two different Ru precursors for the synthesis of Ru/TiO₂ catalysts intended for CO₂ hydrogenation and evaluating their properties using analytical techniques such as XRF, XRD, TEM, XPS and H₂-TPR. Our results show that catalysts prepared from ruthenium nitrosyl nitrate solutions display enhanced reducibility and slightly stronger metal–support interactions compared to those prepared from ruthenium chloride solutions. These features enable higher CO₂ conversion and CH₄ selectivity. The results of this work provide grounds for the targeted chemical precursor selection, while clarifying the reason behind the observed effects on catalytic performance. Full article

In this study, an enzyme-free electrochemical sensor based on zinc oxide (ZnO) nanorods synthesized by the thermal decomposition of zinc acetate is presented. The suggested approach ensures simplicity, environmental friendliness, and scalability of the process without the use of an autoclave or high pressure. The morphology and structure of the samples are studied using SEM, TEM, XRD, Raman, FTIR, XPS, PL, and UV-Vis spectroscopy. It is found that heat treatment at 450 °C increases the degree of crystallinity, increases the size of crystallites, and reduces the concentration of surface defects, which leads to improved optical and electrochemical characteristics of the material. Beyond conventional sensitivity metrics, our study demonstrates that the selective detection of ascorbic acid (AA) and uric acid (UA) can be achieved by controlling the applied potential on a single ZnO electrode, an approach that leverages differences in redox energetics and surface interaction dynamics rather than complex surface functionalization. It is shown in this work that the synthesized ZnO samples subjected to heat treatment in air at 450 °C exhibit high sensitivity to ascorbic acid (9951.87 μA·mM⁻¹·cm⁻²; LoD = 1.11 μM) at a potential of 0.2 V and to uric acid (5762.48 μA·mM⁻¹·cm⁻²; LoD = 1.71 μM) in a phosphate buffer solution (pH 7) at a potential of 0.4 V with a linear range of 3 mM, offering a way to create simplified multicomponent electrochemical biosensors based on potential-controlled selectivity. Full article

Systemic lupus erythematosus (SLE) is a severe autoimmune disease that is challenging to treat due to poor understanding of its pathogenesis and etiology. Clearly understanding and dissecting the therapeutic effects of potential treatment in animal models are important. It has been shown that human alpha-1 antitrypsin (hAAT) holds therapeutic potential for the treatment of autoimmune diseases including lupus. However, the mechanism underlying its protective effect requires further investigation. In the present study, we used a chronic graft-versus-host disease-induced lupus mouse model to test the effect of hAAT on lupus development. We performed adoptive transfer of MHC I-aβ mismatched bm12 splenocytes into hAAT transgenic mice and showed that hAAT significantly blocked the production of anti-dsDNA IgG autoantibodies. Mechanistically, hAAT inhibited T cell activation and proliferation, including that of effector memory T (Tem) and T follicular helper (Tfh) cells. In addition, hAAT suppressed germinal center formation and functions. These results advanced the current understanding of hAAT functions and provide a new insight for the treatment of SLE. Full article