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19 pages, 2345 KB  
Article
Study on Main Controlling Factors of CO2 Enhanced Gas Recovery and Geological Storage in Tight Gas Reservoirs
by Lili Liu, Jinbu Li, Pengcheng Liu, Zepeng Yang, Bin Fu and Xinwei Liao
Processes 2025, 13(10), 3097; https://doi.org/10.3390/pr13103097 - 27 Sep 2025
Viewed by 279
Abstract
Tight gas reservoirs, as important unconventional natural gas resources, face low recovery rates due to low porosity, low permeability, and strong heterogeneity. CO2 Storage with Enhanced Gas Recovery (CSEGR) technology combines CO2 geological storage with natural gas development, providing both economic [...] Read more.
Tight gas reservoirs, as important unconventional natural gas resources, face low recovery rates due to low porosity, low permeability, and strong heterogeneity. CO2 Storage with Enhanced Gas Recovery (CSEGR) technology combines CO2 geological storage with natural gas development, providing both economic and environmental benefits. However, the main controlling factors and influence mechanisms remain unclear. This study utilized the PR-EOS to investigate CH4, CO2, and natural gas physical properties, established a numerical simulation model considering CO2 dissolution and geochemical reactions, and explored the influence of injection scheme, injection rate, production rate, and shut-in condition on CO2 enhanced recovery and storage effectiveness through orthogonal design. Results show that CO2 exhibits significant differences in compressibility factor, density, and viscosity compared to natural gas, enabling piston-like displacement. Intermittent injection slightly outperforms continuous injection in recovery enhancement, while continuous injection provides greater CO2 storage capacity. The ranking of the significance of different influencing factors for enhanced oil recovery is as follows: injection rate > production rate > injection scheme > shut-in condition. For the effect of geological storage of CO2, it is as follows: injection rate > injection scheme > production rate > shut-in condition. During gas injection, supercritical, ionic, and dissolved CO2 continuously increase while mineral CO2 decreases, with storage mechanisms dominated by structural and residual trapping. The study provides scientific basis for optimizing CO2 flooding strategies in tight gas reservoirs. Full article
(This article belongs to the Section Energy Systems)
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25 pages, 8746 KB  
Article
Synergistic Attraction and Ecological Effects of Multi-Source Physical and Chemical Trapping Methods with Different Mechanism Combinations on Rice Pests
by Wei Zeng, Jianping Peng, Chuanhong Feng, Qinghua Chen and Chunxian Jiang
Insects 2025, 16(10), 1001; https://doi.org/10.3390/insects16101001 - 26 Sep 2025
Viewed by 398
Abstract
Comparative experiments on trapping major rice pests using different methods showed that a light-transmitting three-combination trapping method, using different combinations of color plates + insect sex pheromones + transmitting (shielding) light covers + solar-powered automatic insect-attracting ultraviolet lamps, demonstrated significant positive attraction and [...] Read more.
Comparative experiments on trapping major rice pests using different methods showed that a light-transmitting three-combination trapping method, using different combinations of color plates + insect sex pheromones + transmitting (shielding) light covers + solar-powered automatic insect-attracting ultraviolet lamps, demonstrated significant positive attraction and synergistic effects on the simultaneous capture of multiple pests, including rice Sogatella furcifera, Laodelphax striatellus, Chilo suppressalis, and Sesamia inferens and rice leafhoppers, Sitobion miscanthi, Cnaphalocrocis exigua, Parnara guttata, and Naranga aenescens. In addition, the light-transmitting three-combination trapping method has a low benefit-harm ratio and is not easily disturbed by non-target flies (Muscadomestica). The ultraviolet light and transmitting cover in the device had a negative effect on attracting the Cnaphalocrocis medinalis, resulting in a highly significant or significant decrease in its capture rate. The results also showed that the light-shielding double-combination trapping method, which lacks ultraviolet lamp waves and transmitting covers, had no significant difference in the capture rate and insect benefit-harm ratio of C. medinalis adults compared with the glue-type sex lure method, confirming that C. medinalis has a significant negative tendency characteristic to ultraviolet lamp waves and transmitting covers. Therefore, the light-shielding double-combination trapping method using color plates and insect sex pheromones is recommended for monitoring the weakly phototactic C. medinalis. The light-transmitting three-combination trapping method is preferred for the simultaneous capture of multiple major rice pests besides C. medinalis. This study provides a scientific basis for the rational and effective application of multi-source physical and chemical trapping for monitoring and pest control of major crop pests. Full article
(This article belongs to the Section Insect Pest and Vector Management)
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21 pages, 6518 KB  
Article
Topological Rainbow Trapping in One-Dimensional Magnetoelastic Phononic Crystal Slabs
by Wen Xiao, Fuhao Sui, Jiujiu Chen, Hongbo Huang and Tao Luo
Magnetochemistry 2025, 11(10), 83; https://doi.org/10.3390/magnetochemistry11100083 - 25 Sep 2025
Viewed by 238
Abstract
We design a one-dimensional magnetoelastic phononic crystal slab composed of the smart magnetostrictive material Terfenol-D and pure tungsten. Band inversion and topological phase transitions are achieved by modifying the geometric parameters of the non-magnetic medium within the unit cell. The emergence of topological [...] Read more.
We design a one-dimensional magnetoelastic phononic crystal slab composed of the smart magnetostrictive material Terfenol-D and pure tungsten. Band inversion and topological phase transitions are achieved by modifying the geometric parameters of the non-magnetic medium within the unit cell. The emergence of topological interface states within overlapping bandgaps, exhibiting distinct topological properties, along with their robustness against interfacial structural defects, is confirmed. The coupling effects between adjacent topological interface states in a sandwich-like supercell configuration are investigated, and their tunability under external magnetic fields is demonstrated. A Su-Schrieffer-Heeger (SSH) phononic crystal slab system under gradient magnetic fields is proposed. Critically, and in stark contrast to previous static or structurally graded designs, we achieve reconfigurable rainbow trapping of topological interface states solely by reprogramming the gradient magnetic field, leaving the physical structure entirely unchanged. This highly localized, compact, and broadband-tunable topological rainbow trapping system design holds significant promise for applications in elastic energy harvesting, wave filtering, and multi-frequency signal processing. Full article
(This article belongs to the Special Issue Advances in Low-Dimensional Magnetic Materials)
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17 pages, 11436 KB  
Technical Note
Variation in SCM Supply Effects as Reflected by Coupling Relationship with Pycnocline
by Jie Yang, Yunzhao Han, Meng Hou and Lixing Fang
Remote Sens. 2025, 17(19), 3283; https://doi.org/10.3390/rs17193283 - 24 Sep 2025
Viewed by 176
Abstract
The subsurface chlorophyll maximum (SCM) is widely observed in the ocean and is often associated with phytoplankton biomass, where aggregated phytoplankton leads to increased chlorophyll concentrations in the water column. Pycnocline facilitates biomass accumulation by trapping nutrients and providing favorable physical conditions. However, [...] Read more.
The subsurface chlorophyll maximum (SCM) is widely observed in the ocean and is often associated with phytoplankton biomass, where aggregated phytoplankton leads to increased chlorophyll concentrations in the water column. Pycnocline facilitates biomass accumulation by trapping nutrients and providing favorable physical conditions. However, comprehensive studies remain lacking regarding the coupling mechanism between pycnocline and SCM and the extent to which this relationship affects SCM dynamics through biomass accumulation. To investigate the seasonal coupling between the pycnocline and SCM, we established a linear regression model and quantified their relationship using a coupling coefficient, which describes the seasonal transition of SCM in terms of biomass accumulation. The results were validated using BGC-Argo data. Our findings reveal that SCM and the pycnocline consistently exhibit periodic coupling patterns within seasonal cycles, and in the Indian Ocean and the northwestern Pacific, SCM is predominantly biomass-driven during seasons with strong pycnocline coupling (the coupling coefficient ranges between 0.5 and 0.7). In contrast, this coupling weakens significantly in oligotrophic regions (the coupling coefficient remained below 0.3 in more than half of the months studied), where SCM no longer exhibits a clear overlap with peaks in particulate backscattering (BBP). Full article
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20 pages, 3389 KB  
Article
Analytical Modelling of Water Pipeline Start-Up Processes
by Alberto Patiño-Vanegas, Carlos R. Payares Guevara, Enrique Pereira-Batista, Oscar E. Coronado-Hernández and Vicente S. Fuertes-Miquel
Fluids 2025, 10(9), 242; https://doi.org/10.3390/fluids10090242 - 12 Sep 2025
Viewed by 365
Abstract
The start-up process of water-distribution networks has been extensively investigated in recent years, particularly regarding the pressure surges that may occur during such transient events. In this context, researchers have concentrated on exploring physical formulations capable of describing the behaviour of the two [...] Read more.
The start-up process of water-distribution networks has been extensively investigated in recent years, particularly regarding the pressure surges that may occur during such transient events. In this context, researchers have concentrated on exploring physical formulations capable of describing the behaviour of the two interacting phases—water and air—typically resolved through numerical approaches. This paper presents an analytical solution to the nonlinear mathematical model governing the start-up of water pipelines containing a trapped air pocket. The model adopts the rigid water column approximation for the liquid phase and a polytropic gas law to account for the compressibility of the air. The resulting system can be formulated as a second-order nonlinear differential equation. The analytical approach consists of transforming the governing equation into a first-order linear ordinary differential equation, in which the square of the water front velocity is expressed as a function of the water column length. This transformation yields a closed-form solution expressed as a special integral series. The required integrals are evaluated using binomial expansions and incomplete gamma functions, enabling the derivation of a general solution valid within alternating intervals of monotonic motion. A practical application involving an 800 m pipeline is presented. Furthermore, the proposed solution is validated against experimental measurements, demonstrating the accuracy and effectiveness of the analytical approach in capturing the system’s transient behaviour. Full article
(This article belongs to the Special Issue Fluid Mechanics in Water Distribution Systems)
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21 pages, 859 KB  
Review
Idiopathic Inflammatory Myopathy—Molecular Mechanisms Underlying Its Pathogenesis and Physical Therapy Effects
by Aleksandra Markowska and Beata Tarnacka
Int. J. Mol. Sci. 2025, 26(17), 8369; https://doi.org/10.3390/ijms26178369 - 28 Aug 2025
Viewed by 1149
Abstract
Idiopathic inflammatory myopathies (IIMs) are rare autoimmune disorders characterized by muscle weakness. As currently used immunosuppressive treatment presents several limitations, recent investigations focus on elucidating immune and nonimmune molecular mechanisms underlying its pathogenesis. Mitochondrial dysfunctions, endoplasmic reticulum stress, neutrophil dysregulation, and alterations in [...] Read more.
Idiopathic inflammatory myopathies (IIMs) are rare autoimmune disorders characterized by muscle weakness. As currently used immunosuppressive treatment presents several limitations, recent investigations focus on elucidating immune and nonimmune molecular mechanisms underlying its pathogenesis. Mitochondrial dysfunctions, endoplasmic reticulum stress, neutrophil dysregulation, and alterations in myokines and cell death pathways have been implicated in IIM pathophysiology. In this paper, the newest therapeutic strategies targeting reactive oxygen species overproduction, neutrophil extracellular traps formation, and pyroptotic and necroptotic pathways together with mitochondrial transplantations will be presented, and their safety and efficacy will be discussed. As physical therapy constitutes an essential part of IIM management, an additional focus will be directed towards molecular mechanisms underlying the effects of exercises in myositis treatment. Furthermore, the interplay between immune and nonimmune mechanisms will be analyzed and the translational challenges and limitations of current studies will be investigated. Full article
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20 pages, 8352 KB  
Article
Ecological Pest Control in Alpine Ecosystems: Monitoring Asteraceae Phytophages and Developing Integrated Management Protocols in the Three River Source Region
by Li-Jun Zhang, Yu-Shou Ma, Ying Liu and Jun-Ling Wang
Insects 2025, 16(8), 861; https://doi.org/10.3390/insects16080861 - 19 Aug 2025
Viewed by 845
Abstract
Aster spp., a key grass species for the ecological restoration of alpine degraded grasslands on the Qinghai–Tibet Plateau, often suffers from pest damage during its flowering and seed maturation stages, severely limiting the effectiveness of ecological restoration and the sustainable utilization of germplasm [...] Read more.
Aster spp., a key grass species for the ecological restoration of alpine degraded grasslands on the Qinghai–Tibet Plateau, often suffers from pest damage during its flowering and seed maturation stages, severely limiting the effectiveness of ecological restoration and the sustainable utilization of germplasm resources. This study focused on nine widely distributed species of Aster in the Three River Source Region of Qinghai Province, systematically investigated the structure of arthropod communities and the spatiotemporal dynamics of pests, and developed an integrated pest management (IPM) strategy. Through systematic surveys at multiple sites, a total of 109 arthropod species were identified (57 families of insects, 96 species; 7 families of spiders, 13 species). The Diptera (Tephritidae) and Hemiptera (Miridae) were identified as dominant groups. Tephritis angustipennis was determined to be the key pest, with its population density reaching a peak in mid-to-late August (p < 0.05). Based on the occurrence patterns of the pest, an IPM strategy integrating physical, chemical, and biological control methods was proposed: flower head bagging as a physical barrier significantly reduced plant damage but required balancing the risk of seed sterility. A combination lure (broad-spectrum fruit fly lure + a mixture of sugar and vinegar) showed a significant effect in attracting and killing adult flies. In chemical control, spraying a combination of insecticides (DB: 10% β-Cypermethrin aqueous emulsion (9 mL/acre) + 5% avermectin (20 mL/acre)) during the leaf expansion stage to early flowering stage achieved approximately 80% pest mortality within 24 h; additionally, supplementary spraying of 5% broflanilide (30 mL/acre) during the full flowering stage prolonged the efficacy and delayed the development of insecticide resistance. In terms of natural enemy utilization, Lycosidae and Thomisidae demonstrated significant potential for naturally regulating pest populations. Physiological mechanism studies showed that the difference in responses between plant catalase (CAT) activity and insect glutathione S-transferase (GST) activity was a key factor driving control efficacy (the cumulative explanation rate reached 94%). This IPM strategy, by integrating physical barriers, dynamic trapping, targeted spraying, and natural enemy control, significantly enhances control efficiency and ecological compatibility, providing a theoretical basis and technical paradigm for the ecological restoration of degraded alpine grasslands and the sustainable management of medicinal plants in cold regions. Full article
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64 pages, 7848 KB  
Review
A Reassessment of Sarcopenia from a Redox Perspective as a Basis for Preventive and Therapeutic Interventions
by Alessia Arcaro, Alessio Lepore, Giovanni Paolo Cetrangolo, Gianluca Paventi, Paul Richard Julian Ames and Fabrizio Gentile
Int. J. Mol. Sci. 2025, 26(16), 7787; https://doi.org/10.3390/ijms26167787 - 12 Aug 2025
Viewed by 1018
Abstract
The use of a wide variety of antioxidants has been advocated as a means to prevent, delay the progression of, or counteract the adverse consequences of sarcopenia, such as loss of muscle strength, muscle quantity/quality, and physical performance. However, these proposals do not [...] Read more.
The use of a wide variety of antioxidants has been advocated as a means to prevent, delay the progression of, or counteract the adverse consequences of sarcopenia, such as loss of muscle strength, muscle quantity/quality, and physical performance. However, these proposals do not always appear to be supported in the literature by a thorough understanding of the contribution of redox perturbations to the pathogenesis of sarcopenia, nor of the biochemical properties, mechanism of action, pharmacokinetics, and pharmacodynamics of different antioxidants. This review discusses these aspects, aiming to provide a rationale for the selection and use of antioxidants in sarcopenia. After providing a definition of sarcopenia in the context of frailty, we distinguish between oxidative eustress as a physiological response of muscle cells to mild stimulation, such as moderate exercise, mediating their capacity for adaptation and regeneration, and oxidative distress as a pathophysiological response to muscle cell damage and death. The role of oxidative damage to biological macromolecules, both direct and mediated by advanced lipid peroxidation end products and advanced glycation/glycoxidation end products, is examined in detail. Next, we discuss antioxidant defense mechanisms, both enzymatic and non-enzymatic, including redox-sensitive gene regulatory events presided over by nuclear factor erythroid 2-related factor 2, the master regulator of enzymatic antioxidants. The review then discusses criteria for a rational classification of non-enzymatic antioxidants. This is followed by a review of some of the main radical-trapping antioxidants, both phenolic and non-phenolic, whose characteristics are compared. Full article
(This article belongs to the Section Molecular Biology)
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25 pages, 6742 KB  
Article
Reservoir Computing with a Single Oscillating Gas Bubble: Emphasizing the Chaotic Regime
by Hend Abdel-Ghani, A. H. Abbas and Ivan S. Maksymov
AppliedMath 2025, 5(3), 101; https://doi.org/10.3390/appliedmath5030101 - 7 Aug 2025
Viewed by 603
Abstract
The rising computational and energy demands of artificial intelligence systems urge the exploration of alternative software and hardware solutions that exploit physical effects for computation. According to machine learning theory, a neural network-based computational system must exhibit nonlinearity to effectively model complex patterns [...] Read more.
The rising computational and energy demands of artificial intelligence systems urge the exploration of alternative software and hardware solutions that exploit physical effects for computation. According to machine learning theory, a neural network-based computational system must exhibit nonlinearity to effectively model complex patterns and relationships. This requirement has driven extensive research into various nonlinear physical systems to enhance the performance of neural networks. In this paper, we propose and theoretically validate a reservoir-computing system based on a single bubble trapped within a bulk of liquid. By applying an external acoustic pressure wave to both encode input information and excite the complex nonlinear dynamics, we showcase the ability of this single-bubble reservoir-computing system to forecast a Hénon benchmarking time series and undertake classification tasks with high accuracy. Specifically, we demonstrate that a chaotic physical regime of bubble oscillation—where tiny differences in initial conditions lead to wildly different outcomes, making the system unpredictable despite following clear rules, yet still suitable for accurate computations—proves to be the most effective for such tasks. Full article
(This article belongs to the Topic A Real-World Application of Chaos Theory)
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34 pages, 6142 KB  
Review
Grain Boundary Engineering for High-Mobility Organic Semiconductors
by Zhengran He, Kyeiwaa Asare-Yeboah and Sheng Bi
Electronics 2025, 14(15), 3042; https://doi.org/10.3390/electronics14153042 - 30 Jul 2025
Cited by 1 | Viewed by 747
Abstract
Grain boundaries are among the most influential structural features that control the charge transport in polycrystalline organic semiconductors. Acting as both charge trapping sites and electrostatic barriers, they disrupt molecular packing and introduce energetic disorder, thereby limiting carrier mobility, increasing threshold voltage, and [...] Read more.
Grain boundaries are among the most influential structural features that control the charge transport in polycrystalline organic semiconductors. Acting as both charge trapping sites and electrostatic barriers, they disrupt molecular packing and introduce energetic disorder, thereby limiting carrier mobility, increasing threshold voltage, and degrading the stability of organic thin-film transistors (OTFTs). This review presents a detailed discussion of grain boundary formation, their impact on charge transport, and experimental strategies for engineering their structure and distribution across several high-mobility small-molecule semiconductors, including pentacene, TIPS pentacene, diF-TES-ADT, and rubrene. We explore grain boundary engineering approaches through solvent design, polymer additives, and external alignment methods that modulate crystallization dynamics and domain morphology. Then various case studies are discussed to demonstrate that optimized processing can yield larger, well-aligned grains with reduced boundary effects, leading to great mobility enhancements and improved device stability. By offering insights from structural characterization, device physics, and materials processing, this review outlines key directions for grain boundary control, which is essential for advancing the performance and stability of organic electronic devices. Full article
(This article belongs to the Special Issue Feature Papers in Electronic Materials)
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33 pages, 2684 KB  
Review
Biocompatible Natural Polymer-Based Amorphous Solid Dispersion System Improving Drug Physicochemical Properties, Stability, and Efficacy
by Arif Budiman, Helen Ivana, Kelly Angeline Huang, Stella Aurelia Huang, Mazaya Salwa Nadhira, Agus Rusdin and Diah Lia Aulifa
Polymers 2025, 17(15), 2059; https://doi.org/10.3390/polym17152059 - 28 Jul 2025
Cited by 1 | Viewed by 997
Abstract
Poor aqueous solubility still disqualifies many promising drug candidates at late stages of development. Amorphous solid dispersion (ASD) technology solves this limitation by trapping the active pharmaceutical ingredient (API) in a high-energy, non-crystalline form, yet most marketed ASDs rely on synthetic carriers such [...] Read more.
Poor aqueous solubility still disqualifies many promising drug candidates at late stages of development. Amorphous solid dispersion (ASD) technology solves this limitation by trapping the active pharmaceutical ingredient (API) in a high-energy, non-crystalline form, yet most marketed ASDs rely on synthetic carriers such as polyvinylpyrrolidone (PVP) and hydroxypropyl methylcellulose (HPMC), which raise concerns about long-term biocompatibility, residual solvent load, and sustainability. This study summarizes the emergence of natural polymer-based ASDs (NP-ASDs), along with the bond mechanism reactions through which these natural polymers enhance drug performance. As a result, NP-ASDs exhibit improved physical stability and significantly enhance the dissolution rate of poorly soluble drugs. The structural features of natural polymers play a critical role in stabilizing the amorphous state and modulating drug release profiles. These findings support the growing potential of NP-ASDs as sustainable and biocompatible alternatives to synthetic carriers in pharmaceutical development. Full article
(This article belongs to the Section Biobased and Biodegradable Polymers)
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18 pages, 564 KB  
Article
Electrons in Quantum Dots on Helium: From Charge Qubits to Synthetic Color Centers
by Mark I. Dykman and Johannes Pollanen
Entropy 2025, 27(8), 787; https://doi.org/10.3390/e27080787 - 25 Jul 2025
Viewed by 633
Abstract
Electrons trapped above the surface of helium provide a means to study many-body physics free from the randomness that comes from defects in other condensed-matter systems. Localizing an electron in an electrostatic quantum dot makes its energy spectrum discrete, with controlled level spacing. [...] Read more.
Electrons trapped above the surface of helium provide a means to study many-body physics free from the randomness that comes from defects in other condensed-matter systems. Localizing an electron in an electrostatic quantum dot makes its energy spectrum discrete, with controlled level spacing. The lowest two states can act as charge qubit states. In this paper, we study how the coupling to the quantum field of capillary waves on helium—known as ripplons—affects electron dynamics. As we show, the coupling can be strong. This bounds the parameter range where electron-based charge qubits can be implemented. The constraint is different from the conventional relaxation time constraint. The electron–ripplon system in a dot is similar to a color center formed by an electron defect coupled to phonons in a solid. In contrast to solids, the coupling in the electron on helium system can be varied from strong to weak. This enables a qualitatively new approach to studying color center physics. We analyze the spectroscopy of the pertinent synthetic color centers in a broad range of the coupling strength. Full article
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27 pages, 4412 KB  
Review
Coupling Agents in Acoustofluidics: Mechanisms, Materials, and Applications
by Shenhao Deng, Yiting Yang, Menghui Huang, Cheyu Wang, Enze Guo, Jingui Qian and Joshua E.-Y. Lee
Micromachines 2025, 16(7), 823; https://doi.org/10.3390/mi16070823 - 19 Jul 2025
Viewed by 2913
Abstract
Acoustic coupling agents serve as critical interfacial materials connecting piezoelectric transducers with microfluidic chips in acoustofluidic systems. Their performance directly impacts acoustic wave transmission efficiency, device reusability, and reliability in biomedical applications. Considering the rapidly growing body of research in the field of [...] Read more.
Acoustic coupling agents serve as critical interfacial materials connecting piezoelectric transducers with microfluidic chips in acoustofluidic systems. Their performance directly impacts acoustic wave transmission efficiency, device reusability, and reliability in biomedical applications. Considering the rapidly growing body of research in the field of acoustic microfluidics, this review aims to serve as an all-in-one reference on the role of acoustic coupling agents and relevant considerations pertinent to acoustofluidic devices for anyone working in or seeking to enter the field of disposable acoustofluidic devices. To this end, this review seeks to summarize and categorize key aspects of acoustic couplants in the implementation of acoustofluidic devices by examining their underlying physical mechanisms, material classifications, and core applications of coupling agents in acoustofluidics. Gel-based coupling agents are particularly favored for their long-term stability, high coupling efficiency, and ease of preparation, making them integral to acoustic flow control applications. In practice, coupling agents facilitate microparticle trapping, droplet manipulation, and biosample sorting through acoustic impedance matching and wave mode conversion (e.g., Rayleigh-to-Lamb waves). Their thickness and acoustic properties (sound velocity, attenuation coefficient) further modulate sound field distribution to optimize acoustic radiation forces and thermal effects. However, challenges remain regarding stability (evaporation, thermal degradation) and chip compatibility. Further aspects of research into gel-based agents requiring attention include multilayer coupled designs, dynamic thickness control, and enhancing biocompatibility to advance acoustofluidic technologies in point-of-care diagnostics and high-throughput analysis. Full article
(This article belongs to the Special Issue Recent Development of Micro/Nanofluidic Devices, 2nd Edition)
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22 pages, 10488 KB  
Article
Morphological and Functional Evolution of Amorphous AlN Thin Films Deposited by RF-Magnetron Sputtering
by Maria-Iulia Zai, Ioana Lalau, Marina Manica, Lucia Chiriacescu, Vlad-Andrei Antohe, Cristina C. Gheorghiu, Sorina Iftimie, Ovidiu Toma, Mirela Petruta Suchea and Ștefan Antohe
Surfaces 2025, 8(3), 51; https://doi.org/10.3390/surfaces8030051 - 17 Jul 2025
Viewed by 2789
Abstract
Aluminum nitride (AlN) thin films were deposited on SiO2 substrates by RF-magnetron sputtering at varying powers (110–140 W) and subsequently subjected to thermal annealing at 450 °C under nitrogen atmosphere. A comprehensive multi-technique investigation—including X-ray reflectometry (XRR), X-ray diffraction (XRD), scanning electron [...] Read more.
Aluminum nitride (AlN) thin films were deposited on SiO2 substrates by RF-magnetron sputtering at varying powers (110–140 W) and subsequently subjected to thermal annealing at 450 °C under nitrogen atmosphere. A comprehensive multi-technique investigation—including X-ray reflectometry (XRR), X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), optical profilometry, spectroscopic ellipsometry (SE), and electrical measurements—was performed to explore the physical structure, morphology, and optical and electrical properties of the films. The analysis of the film structure by XRR revealed that increasing sputtering power resulted in thicker, denser AlN layers, while thermal treatment promoted densification by reducing density gradients but also induced surface roughening and the formation of island-like morphologies. Optical studies confirmed excellent transparency (>80% transmittance in the near-infrared region) and demonstrated the tunability of the refractive index with sputtering power, critical for optoelectronic applications. The electrical characterization of Au/AlN/Al sandwich structures revealed a transition from Ohmic to trap-controlled space charge limited current (SCLC) behavior under forward bias—a transport mechanism frequently present in a material with very low mobility, such as AlN—while Schottky conduction dominated under reverse bias. The systematic correlation between deposition parameters, thermal treatment, and the resulting physical properties offers valuable pathways to engineer AlN thin films for next-generation optoelectronic and high-frequency device applications. Full article
(This article belongs to the Special Issue Surface Engineering of Thin Films)
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20 pages, 1893 KB  
Article
Acute Dermatotoxicity of Green-Synthesized Silver Nanoparticles (AgNPs) in Zebrafish Epidermis
by Grace Emily Okuthe and Busiswa Siguba
Toxics 2025, 13(7), 592; https://doi.org/10.3390/toxics13070592 - 15 Jul 2025
Viewed by 591
Abstract
Silver nanoparticles (AgNPs), lauded for their unique antibacterial and physicochemical attributes, are proliferating across industrial sectors, raising concerns about their environmental fate, in aquatic systems. While “green” synthesis offers a sustainable production route with reduced chemical byproducts, the safety of these AgNPs for [...] Read more.
Silver nanoparticles (AgNPs), lauded for their unique antibacterial and physicochemical attributes, are proliferating across industrial sectors, raising concerns about their environmental fate, in aquatic systems. While “green” synthesis offers a sustainable production route with reduced chemical byproducts, the safety of these AgNPs for aquatic fauna remains uncertain due to nanoparticle-specific effects. Conversely, mast cells play crucial roles in fish immunity, orchestrating innate and adaptive immune responses by releasing diverse mediators and recognizing danger signals. Goblet cells are vital for mucosal immunity and engaging in immune surveillance, regulation, and microbiota interactions. The interplay between these two cell types is critical for maintaining mucosal homeostasis, is central to defending against fish diseases and is highly responsive to environmental cues. This study investigates the acute dermatotoxicity of environmentally relevant AgNP concentrations (0, 0.031, 0.250, and 5.000 μg/L) on zebrafish epidermis. A 96 h assay revealed a biphasic response: initial mucin hypersecretion at lower AgNP levels, suggesting an early stress response, followed by a concentration-dependent collapse of mucosal integrity at higher exposures, with mucus degradation and alarm cell depletion. A rapid and generalized increase in epidermal mucus production was observed across all AgNP exposure groups within two hours of exposure. Further mechanistic insights into AgNP-induced toxicity were revealed by concentration-dependent alterations in goblet cell dynamics. Lower AgNP concentrations initially led to an increase in both goblet cell number and size. However, at the highest concentration, this trend reversed, with a significant decrease in goblet cell numbers and size evident between 48 and 96 h post-exposure. The simultaneous presence of neutral and acidic mucins indicates a dynamic epidermal response suggesting a primary physical barrier function, with acidic mucins specifically upregulated early on to enhance mucus viscosity, trap AgNPs, and inhibit pathogen invasion, a clear defense mechanism. The subsequent reduction in mucin-producing cells at higher concentrations signifies a critical breakdown of this protective strategy, leaving the epidermis highly vulnerable to damage and secondary infections. These findings highlight the vulnerability of fish epidermal defenses to AgNP contamination, which can potentially compromise osmoregulation and increase susceptibility to threats. Further mechanistic research is crucial to understand AgNP-induced epithelial damage to guide sustainable nanotechnology. Full article
(This article belongs to the Section Ecotoxicology)
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