Search Results (88,741)

The aim of this paper is to present a more complete analysis of the theoretical concepts and experimental aspects of the physics of photoproduction interactions involving nuclei. We thus determine the relative contributions of excited nucleon, $p\pi$, and $p\pi \pi$ resonances and $\rho$, $\eta$, $\omega$ and K production, as well as the subsequent decay channels leading to neutrino and $\gamma$-ray production. This treatment is based, in large part, on the most recent and extensive empirical data on particle photoproduction interactions off protons and He nuclei. It is shown that, in astrophysical sources with steep proton energy spectra, the $\Delta$(1232) resonance channel clearly dominates. However, a blend of $N^{*}$ resonances at ∼1400 GeV can contribute as much as 20% to the neutrino flux. It is further found that $\gamma$–He interactions produce approximately 10% of astrophysical pions, as compared with $\gamma p$ interactions. Full article

Background/Objectives: In severe peripheral artery disease (PAD) with limb ischemia, hypercholesterolemia (HC) is associated with impaired neovascularization. Extracellular vesicles (EVs) are present within ischemic muscles, and they contain microRNAs (miRs) involved in several biological functions, including angiogenesis and neovascularization. Methods: We used a mouse model of PAD and compared the response to hindlimb ischemia in hypercholesterolemic ApoE^−/− vs. normocholesterolemic mice. Next-generation sequencing (NGS) was used to perform full miR expression profiling in ischemic skeletal muscles and in EVs of varying sizes—large EVs (lEVs) and small EVs (sEVs)—within these muscles. Results: We identified several miRs with potential pro-angiogenic effects (angiomiRs) that are reduced by HC in lEVs (Let-7b-5p, miR-151-3p, Let-7c-5p) or sEVs (miR-21a-5p, miR-196b-5p, miR-340-5p). As proof of principle, we showed that the overexpression of Let-7b-5p in lEVs, or miR-21a-5p in sEVs, can significantly increase the angiogenic capacity of these EVs in vitro. HC also impaired the enrichment of specific angiomiRs in lEVs (miR-100-5p), sEVs (miR-142a-3p), or in both lEVs and sEVs (miR-146b-5p). In silico approaches, including the prediction of miR targets, pathway unions, and gene unions, identified the resulting predictive effects of HC-modulated miRs in EVs on processes with key roles in the modulation of angiogenesis and neovascularization, such as the regulation of the actin cytoskeleton and focal adhesion and the HIF-1, MAPK, AMPK, and PI3K-Akt signaling pathways. Conclusions: Our results constitute an important first step towards the identification of specific miRs that could be targeted to improve EV angiogenic function in hypercholesterolemic conditions and reduce tissue ischemia in patients with severe PAD. Full article

The advent of electric propulsion for new aircraft designs necessitates the optimization of propeller aerodynamic performance and the reduction of acoustic signatures. Variable-pitch propellers present a promising solution, offering the flexibility to adjust blade angles in response to different flight conditions. The study investigates the performance of blade pitch configurations tailored to specific flight conditions. Rather than a dynamic pitch change, the research evaluates discrete pitch settings coupled with corresponding advance ratios to identify optimal operating points. Findings show that increasing collective pitch in response to a higher advance ratio (forward flight) successfully maintains aerodynamic efficiency and thrust, with an expected increase in torque. While this adjustment leads to an anticipated rise in noise due to higher aerodynamic loading, results reveal that a collective pitch increment of $+5°$ actively suppresses broadband noise at frequencies above 2 kHz. Analysis of the flow field and surface pressure fluctuations indicates this suppression is directly attributed to the mitigation of outboard propeller stall. Ultimately, this work demonstrates the feasibility of using collective pitch adjustments not only to enhance flight performance but also to actively control and suppress components of the propeller noise signature, such as the broadband noise. Full article

Oxalic acid serves as an environmentally benign leaching agent, exhibiting strong reducing and complexing capabilities. In the oxalic acid leachate derived from vanadium-bearing shale, aluminum ions are present as major impurities. Achieving efficient and deep separation of vanadium from aluminum remains a key technical challenge. This study investigates the selective separation of vanadium and aluminum from oxalic acid leaching solutions using solvent extraction with Aliquat 336, supported by density functional theory (DFT) calculations. Experimental results demonstrate that, under optimized conditions, Aliquat 336 enables effective separation of vanadium from aluminum. DFT analysis elucidates the molecular-level interaction mechanism, revealing that the binding affinity of Aliquat 336 for [VO(C₂O₄)₂]²⁻ (ΔG = −287.96 kJ/mol) is significantly stronger than for [Al(C₂O₄)₂]⁻ (ΔG = −186.68 kJ/mol). These results provide a solid thermodynamic basis for the observed selectivity and establish a robust theoretical framework for developing high-efficiency separation processes. This work thus clarifies, for the first time, the mechanistic foundation of vanadium–aluminum separation in oxalic acid systems. Full article

2-({3-[2-(1-cyclohexen-1-yl)ethyl]-6,7-dimethoxy-4-oxo-3,4-dihydro-2-quinazolinyl}sulfanyl)-N-(4-ethylphenyl)butanamide (K284-6111; K284), the representative CHI3L1 inhibitor, has interesting biological activities, including anti-cancer and anti-inflammatory effects on neuroinflammation. Following our hit-to-lead program, we report the most active novel derivative, named CBJL-025, 2-((6,7-dimethoxy-4-oxo-3-(4-(trifluoromethyl)phenethyl)-3,4-dihydroquinazolin-2-yl)thio)-N-(4-ethylphenyl)butanamide. The title compound, CBJL-025, was successfully synthesized by S-alkylation of the p-trifluoromethyl phenethyl group possessing quinazoline and the corresponding bromide. The structure of CBJL-025 was confirmed by ¹H and ¹³C nuclear magnetic resonance (NMR) and high-resolution mass spectrometry (HRMS). Full article

Industrial-grade printed circuit boards (PCBs) exhibit high structural order and inherent geometric symmetry, where minute surface defects essentially constitute symmetry-breaking anomalies that disrupt topological integrity. Detecting these anomalies is quite challenging due to issues like scale variation and low contrast. Therefore, this paper proposes a symmetry-aware object detection framework, DAS-YOLO, based on an improved YOLOv11. The U-shaped adaptive feature extraction module (Def-UAD) reconstructs the C3K2 unit, overcoming the geometric limitations of standard convolutions through a deformation adaptation mechanism. This significantly enhances feature extraction capabilities for irregular defect topologies. A semantic-aware module (SADRM) is introduced at the backbone and neck regions. The lightweight and efficient ESSAttn improves the distinguishability of small or weak targets. At the same time, to address information asymmetry between deep and shallow features, an iterative attention feature fusion module (IAFF) is designed. By dynamically weighting and calibrating feature biases, it achieves structured coordination and balanced multi-scale representation. To evaluate the validity of the proposed method, we carried out comprehensive experiments using publicly accessible datasets focused on PCB defects. The results show that the Recall, mAP@50, and mAP@50-95 of DAS-YOLO reached 82.60%, 89.50%, and 46.60%, respectively, which are 3.7%, 1.8%, and 2.9% higher than those of the baseline model, YOLOv11n. Comparisons with mainstream detectors such as GD-YOLO and SRN further demonstrate a significant advantage in detection accuracy. These results confirm that the proposed framework offers a solution that strikes a balance between accuracy and practicality in addressing the key challenges in PCB surface defect detection. Full article

The present study evaluates the impact of cavitation on the performance of the chemical refining of rapeseed oils and the enzymatic interesterification of fat blends using a powerful UP400S ultrasonicator (400 W, 20 kHz). Ultrasound-assisted alkali neutralization achieved efficiency comparable to that of the conventional 60 min process in only 7 min, with similar refining losses (5.04–6.80 wt.%), although slightly higher lipid peroxidation was observed. Performing the ultrasound cavitation under a protective nitrogen atmosphere minimized the formation of lipid peroxides and their breakdown products (i.e., hexanal, nonanal), partially protected tocopherols, and improved oxidative stability (IP at 120 °C = 3.9–4.4 h). Ultrasound-assisted enzymatic interesterification (EIE) of palm kernel fat and a palm stearin blend catalyzed by immobilized lipases (Lipozyme TL IM, Lipozyme RM IM, Novozyme 435) was carried out for the first time. Cavitation accelerated triacylglycerol rearrangement, reduced reaction time from 6 h (9.0·10⁻³ to 1.6·10⁻² min⁻¹) to only 1 h (5.5·10⁻² to 1.2·10⁻¹ min⁻¹), and significantly affected melting point stabilization and solid fat content profile. In summary, ultrasound cavitation substantially enhanced mass transfer and reaction kinetics, demonstrating strong potential for process intensification in the edible oil industry. Further optimization of reaction conditions is required before large-scale industrial implementation. Full article

Traditional polysaccharide extraction suffers from low efficiency and high energy consumption, while deep eutectic solvents (DESs) are promising sustainable solvents. This study used DES ChCl-LA (1:2) with ultrasonic assistance to extract polysaccharides from red alga A.taxiformis. Optimized via single-factor experiments and response surface methodology (350 W, 1:30 g/mL, 75 °C), the yield reached 11.28% ± 0.50% (1.5 times higher than that obtained by water extraction). Structural characterization revealed that the DES extract was an acidic polysaccharide, mainly composed of galactose (89.2%), glucose (4.9%), xylose (4.9%), and glucuronic acid (1.0%), with a weight-average molecular weight of 99.88 kDa. Density functional theory and molecular dynamics simulations showed that ChCl-LA enhanced galactose solubility via stronger hydrogen bonding (−25.33 vs. −5.06 kcal/mol for water). Notably, the immunological activity of the DES-extracted polysaccharide was significantly compromised compared to the water-extracted counterpart (p < 0.05). At a concentration of 0.25 mg/mL, the water-extracted polysaccharide-treated group exhibited a 33.98% higher neutral red phagocytosis rate in macrophages, a nitric oxide (NO) secretion level of 34.14 μmol/L (94.98% higher) compared with the DES-extracted polysaccharide group, as well as significantly higher secretion levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). The observed disparity in bioactivity is likely due to the distinct chemical profiles resulting from the two extraction methods, including the significantly reduced molecular weight and potential alterations of sulfation degree, monosaccharide composition, and protein content in the DES-extracted polysaccharide. This mechanistic perspective is supported by the relevant literature on the structure–activity relationships of polysaccharides. This study demonstrates the potential of ChCl-LA and elucidates the complex effects of extraction methods on polysaccharide’s structure and function, thereby informing the high-value utilization of A. taxiformis in functional foods. Full article

Power supply for traction substations (TSs) of AC railways has traditionally been provided by 110–220 kV overhead transmission lines (OHL). These OHLs can be damaged during strong winds and ice formation. Furthermore, these lines generate significant electromagnetic fields (EMFs), which adversely affect maintenance personnel, the public, and the environment. Mitigating the resulting damages requires the establishment of protection zones, necessitating significant land allocation. Enhancing the reliability of power supply to traction substations and reducing EMF levels can be achieved through the use of gas-insulated lines (GIL), whose application in the power industry of many countries is continuously increasing. The aim of the research presented in this article was to develop computer models for determining the EMF of a GIL supplying a group of traction substations, taking into account actual traction loads characterized by non-sinusoidal waveforms and asymmetry. To solve this problem, an approach implemented in the Fazonord AC-DC software package, based on the use of phase coordinates, was applied. This allowed for the correct accounting of the skin effect and proximity effect in the massive current-carrying parts of the GIL, as well as the influence of asymmetry and harmonic distortions. The simulation results showed that the use of GIL brings the voltage unbalance factors at the 110 kV busbars of the traction substations within the permissible range, with the maximum values of these coefficients not exceeding 2%. The results of the harmonic distortion assessment demonstrated a significant reduction in harmonic distortion factors in the 110 kV network for the GIL compared to the OHL. The performed electromagnetic field calculations confirmed that the GIL generates magnetic field strengths one order of magnitude lower than those of the OHL. The obtained results lead to the conclusion that the use of gas-insulated lines for powering traction substations is highly effective, ensuring increased reliability, improved power quality, and a reduced negative impact of EMF on personnel, the public, the environment, and electronic equipment. Full article

This study aims to evaluate the robustness of the well proved Aungier meanline model, originally developed for air and steam turbines, on Organic Rankine Cycles (ORC) turbines. More specifically, the study focuses on two pure-impulse axial turbines with partial admission and using various working fluids, including zeotropic mixtures. To this end, a three-part numerical model was developed to adapt this type of meanline model to a prediction-oriented methodology rather than a design-oriented one. Using inlet and outlet pressures, inlet temperature, and rotational speed as inputs, the model provides the resulting mass flow rate through the turbine as well as its performance characteristics. The model predictions are compared against an extensive experimental dataset comprising more than 300 operating points obtained with three pure fluids—R1233zd(E), NOVEC™ 649, and HFE7000—and three zeotropic mixtures. The model demonstrates good predictive accuracy over a wide range of operating conditions, including very low velocity ratios corresponding to severe off-design operation. Specifically, the mass flow rate is predicted with a Mean Absolute Percentage Error (MAPE) ranging from 1.23% to 3.31%, depending on the working fluid. Furthermore, over an experimental specific work range of 5 to 15 kJ/kg, the predicted numerical work exhibits a MAPE of 7.04% for 102 experimental points corresponding to the main dataset (R1233zd(E)). Finally, the total-to-total efficiency is predicted within ±4 efficiency points, showing a very good trend over a velocity ratio range from 0.06 to 0.36. Full article

Background: This study is part of the HEAL ITALIA partnership, funded by the National Recovery and Resilience Plan (PNRR) and the European Union. Heart failure (HF) is a serious health problem, with a reduced density of the β1-adrenergic receptor (β1-AR) in the myocardium as a hallmark. It is unclear whether this downregulation causes dysfunction or represents an epiphenomenon. Recent evidence implicates oxidative stress and mitochondrial signaling, particularly through the 18 kDa translocator protein (TSPO), in the regulation of the β1-AR, with possible modulation by estrogen. Objectives: To determine (1) the role of β1-AR desensitization in the onset and development of HF; (2) whether monocytes can represent a suitable ex vivo model for sex-oriented mechanistic studies in the cardiac field; (3) whether monocytes isolated from peripheral blood of patients can represent a diagnostic and/or therapy response biomarker by monitoring β1-AR density; (4) whether and how the mitochondrial receptor TSPO is involved in the β1-AR dysregulation observed in HF; and (5) whether the mechanisms linked to the onset of HF are regulated in a sex-specific manner through the effect of estrogen and/or the X chromosome on the expression of specific microRNAs. Methods: Using an integrated in vitro-ex vivo-in vivo methodological approach, we will evaluate the density of β1/β2-AR receptors, the downstream signaling (GRK2/β-arrestin), mitochondrial and redox parameters, and miRNA profiles in human monocytes and cardiomyocytes, and in mouse hearts after HF following pressure overload. Conclusions: The goal is to better understand the mechanisms underlying β1-AR desensitization, verify monocytes as peripheral markers of disease progression and response to therapy, and provide potentially useful information for the development of gender-specific therapies for heart failure. Full article

As distribution networks become increasingly intelligent, primary–secondary integrated distribution switches are replacing the traditional electromagnetic type. However, the high degree of integration intensifies inherent electromagnetic compatibility (EMC) challenges. This paper presents a field-circuit hybrid full-wave model to investigate switch characteristics during lightning strikes. A 3D full-wave model of the switch and a distributed parameter circuit model of the connecting lines are coupled via a network parameter matrix. This approach comprehensively accounts for the impacts of transmission lines and structural components on electromagnetic disturbances. Simulation and experimental results reveal that lightning strikes induce high-frequency damped oscillatory waves, primarily caused by traveling wave reflections along overhead lines. The characteristic frequency of disturbance is inversely proportional to the transmission line length. Additionally, internal components significantly influence this frequency; specifically, a larger voltage dividing capacitance in the voltage transformer results in a lower frequency. Model validation was performed using a 20 m transmission line setup. A 75 kV standard lightning impulse was injected into Phase B. At a distance of 500 mm from the voltage transformer, the measured radiated electric field amplitude was 14.12 kV/m (deviation < 5%), and the characteristic frequency was 1.11 MHz (deviation < 20%). These findings offer vital guidance for the lightning protection and EMC design of primary–secondary integrated distribution switches. Full article

Unmanned aerial vehicles open new possibilities for developing technologies that support more sustainable and efficient agriculture. This paper presents a non-invasive method for repelling rodents from crop fields using ultrasound. The proposed system is implemented as a spherical-cap ultrasound loudspeaker array consisting of eight transducers, mounted on a drone that overflies the field while emitting sound in the 20–70 kHz range. The hardware design includes both the loudspeaker array and a custom printed circuit board hosting power amplifiers and a signal generator tailored to drive multiple ultrasonic transducers. In parallel, a genetic algorithm is used to compute flight paths that maximize coverage and increase the probability of driving rodents away from the protected area. As part of the validation phase, artificial intelligence models for rodent detection using a thermal camera are developed to provide quantitative feedback on system performance. The complete prototype is evaluated through a series of experiments conducted both in controlled laboratory conditions and in the field. Field trials highlight which parts of the concept are already effective and identify open challenges that need to be addressed in future work to move from a research prototype toward a deployable product. Full article

This paper presents the results of modeling the DC and dynamic characteristics of an alkaline electrolyzer. A model of such an electrolyzer is proposed as a subcircuit for the SPICE software. This model describes DC and dynamic current–voltage characteristics of the electrolyzer, taking into account the effect of solution concentration on the electrolyzer internal resistance and electrolyte capacitance, as well as the resistance and inductance of the leads. Using this model, one can calculate the voltage and current waveforms across the electrolyzer, as well as the gas flow rate produced by the electrolyzer. The correctness of the developed model was experimentally verified by powering the electrolyzer using a DC source and by powering the device using a voltage source, generating a rectangular pulse train with an adjustable frequency and duty cycle. The measurement system is described, and the obtained calculation and measurement results are presented and discussed. It was shown that the obtained calculation results differed minimally from the measurement results across a wide range of frequencies (from 0 to 50 kHz), duty cycles (from 0.3 to 0.7) of the supply voltage, and concentrations of the electrolyte (from 0.1 to 10%). The mean square error, normalized to peak measured values of each considered quantity, does not exceed 4%. Full article

To clarify the phylogenetic relationship between Abutilon theophrasti M. and other Malvaceae plants, the chloroplast genome of A. theophrasti was assembled, annotated, and analyzed. The complete chloroplast genome was sequenced using the Illumina NovaSeq 6000 platform. Bioinformatics methods were employed to systematically analyze its genomic structure, repetitive sequences, nucleic acid diversity, and codon preference. Additionally, a phylogenetic tree was constructed by integrating chloroplast genomic sequences from other Malvaceae species. The results showed that the chloroplast genome of A. theophrasti was 160,440 bp in length with a GC content of 36.89%, exhibiting a typical tetrad structure. A total of 130 coding genes were annotated, including 85 mRNA genes, 37 tRNA genes, and 8 rRNA genes, with no pseudogenes detected. Codon preference analysis indicates that leucine (Leu) is the most frequently used amino acid. There are 31 codons with a relative synonymous codon usage (RSCU) value greater than 1, most of which end with A or U. The genome contains 61 scattered repeat sequences and 288 simple repeat sequences (SSR). Ka/Ks analysis revealed that the overall chloroplast genes of A. theophrasti undergo purifying selection, while genes such as psbK and rps12 are subjected to positive selection, which may be associated with adaptive evolution. Phylogenetically, A. theophrasti is most closely related to its congener A. indicum, followed by a clade comprising M. cathayensis and Malva crispa of the genus Malva. This study enhances the understanding of the phylogenetic relationship of A. theophrasti and provides a theoretical basis for the genetic improvement and breeding strategies of A. theophrasti and other Malvaceae plants. Full article