Search Results (306)

Industrial dyes remain a major source of water pollution and pose environmental and human health risks because of their carcinogenic and mutagenic properties. Of these, Congo Red dye shows high toxicity and stability in aquatic environments; therefore, removing it from water bodies is desirable. Among numerous methods, ultrasound-assisted catalysis for dye degradation remains promising. This work investigates the combined effect of ultrasound and an iron oxide (Fe₂O₃) catalyst for degrading Congo Red (CR) dye (a model industrial dye). The characterization of Fe₂O₃ particles was performed through SEM, XRD, and FTIR analyses. CR degradation was performed at 100–600 W ultrasound power, 0–120 min, and with 5–20% (w/v) Fe₂O₃. The ultrasound-driven CR degradation was compared with and without the Fe₂O₃ catalyst. Using ultrasound alone, maximum CR degradation reached 39.30%, while adding Fe₂O₃ (20% w/v) during ultrasonication enabled 93.20% CR degradation in 120 min. The optimized conditions for maximum CR degradation (93.21%) were 600 W, 30 °C, 120 min, and 20% w/v Fe₂O₃. The enhancement was attributed to acoustic cavitation, heterogeneous bubble nucleation on Fe₂O₃ surfaces, improved mass transfer, Fe³⁺/Fe²⁺ redox cycling, and reactive oxygen species generation. Further, the kinetic analysis indicated that the CR degradation followed a pseudo-second-order kinetic model, showing strong agreement with experimental data (R² = 0.96). A detailed mechanism was proposed involving CR adsorption, azo-bond cleavage, aromatic ring hydroxylation, fragmentation, ring opening, and progressive oxidation into smaller intermediates. Overall, the present study demonstrates that ultrasound combined with Fe₂O₃ effectively enhanced Congo Red removal/decolorization under the investigated laboratory-scale conditions. Full article

The growing demand for sustainable protein ingredients has intensified interest in legumes as strategic raw materials for plant-based food applications. Legume proteins, mainly composed of globulins, albumins, vicilins, and legumins, exhibit relevant nutritional and techno-functional properties, including solubility, emulsification, foaming, gelation, and water- or oil-binding capacity. However, conventional extraction methods, particularly alkaline extraction followed by isoelectric precipitation, often involve extreme pH conditions, high water and chemical consumption, long processing times, and possible losses in protein functionality. Ultrasound-assisted extraction (UAE) has emerged as a promising process intensification strategy for improving protein recovery from legume matrices. Its mechanism is mainly associated with acoustic cavitation, which generates microjets, shear forces, shock waves, and microturbulence, promoting cellular disruption, solvent penetration, and mass-transfer enhancement. In addition to increasing extraction efficiency, UAE can induce controlled structural modifications in proteins, potentially improving solubility, emulsifying activity, foaming behavior, and gelation. Nevertheless, excessive sonication may cause aggregation, oxidation, and functional deterioration. This review discusses the principles, effects, advantages, and limitations of UAE for legume protein extraction, emphasizing its potential for the sustainable production of techno-functional plant-based protein ingredients. Full article

Histotripsy is an emerging nonthermal, nonionizing, and noninvasive focused ultrasound therapy that uses acoustic cavitation to mechanically disrupt targeted tissue. In the liver, histotripsy may offer several advantages over conventional locoregional therapies, including treatment without percutaneous probes, treatment of select tumors near vascular or biliary structures, and potential proposed preclinical immunomodulatory effects. Early clinical studies, such as the THERESA and #HOPE4LIVER trials, have demonstrated high technical success rates and relatively low rates of major complications; however, expanding real-world evidence has identified clinically important complications including vascular injury, portal vein thrombosis, and acute kidney injury. Additional prospective studies are needed to determine long-term local tumor control, survival benefits, optimal patient selection, and the role of histotripsy in combination with systemic therapies and other locoregional treatments. This narrative review summarizes the possible mechanism of action, clinical outcomes, safety profile, patient selection considerations, and future directions of histotripsy for the treatment of primary and metastatic liver tumors. Full article

Introduction: The fetal ganglionic eminence (GE) is a transient brain structure involved in interneuron development; its abnormalities may be associated with malformations of cortical development (MCD). This systematic review evaluated the feasibility and clinical value of transvaginal neurosonography for fetal GE assessment. Material and Methods: PubMed, Scopus, and Web of Science were searched from January 2015 to June 2026. Human in vivo ultrasound studies of the fetal GE were included. Results: Thirteen studies comprising 890 fetuses were included. GE visualization ranged from 71% to 100%, with highest rates using dedicated three-dimensional transvaginal neurosonography at 9–22 weeks. Measurement reproducibility was good to excellent. GE cavitation and enlargement were associated with MCD in selected high-risk cohorts, but reported frequencies varied substantially. Conclusions: Transvaginal neurosonography permits feasible and reproducible visualization of the fetal GE in experienced hands. Small studies, heterogeneous protocols, and limited long-term outcome data preclude routine GE assessment at present. Full article

Per- and polyfluoroalkyl substances (PFASs) are pollutants that have demonstrated a high level of environmental persistence and are very difficult to remediate. Sonochemical processes have shown considerable potential for PFAS destruction, but the relationships between ultrasound operating conditions, cavitation behavior, and reactor performance remain insufficiently understood. Ultrasonic cavitation is a key mechanism in sonochemical processes, yet the coupled effects of ultrasound frequency, cavitation activity, energy efficiency, and bubble characteristics remain insufficiently understood. This study systematically investigated these interactions in an intermediate scale sonochemical reactor operated at 680, 850, and 950 kHz under different power densities. Cavitation was quantified using potassium iodide (KI) dosimetry, while energy transfer and efficiency were evaluated by calorimetric analysis. Bubble size, bubble concentration and zeta potential were measured to characterize cavitation-generated nanobubbles and added argon nanobubbles, and their interfacial properties. The results showed that ultrasound frequency strongly influenced cavitation behavior and energy utilization. The 850 kHz system exhibited the highest cavitation activity, whereas the 950 kHz system showed the highest calorimetric efficiency. Increased power density enhanced cavitation intensity but also increased thermal losses. Higher frequencies produced smaller bubbles, while power density and solution properties had weaker effects on bubble size and surface charge. Zeta potential measurements revealed consistently negative surface charges, with markedly greater negative values in the presence of perfluorooctanoic acid (PFOA) and argon nanobubbles, consistent with possible interfacial association of PFAS rather than direct confirmation of adsorption. Nanobubble concentration and size were also highly dependent on ultrasound and solution properties, with ultrasound promoting nanobubble generation and PFAS contributing to their stability and growth. Overall, the findings demonstrate that cavitation activity, energy efficiency, and bubble interfacial properties are strongly interdependent and primarily governed by ultrasonic frequency. This work provides new insights into sonochemical reactor characterization and optimization and identifies operating conditions that may be beneficial for future PFAS degradation studies and other advanced oxidation processes. Full article

Background/Objectives: The blood–brain barrier (BBB) remains a major obstacle to effective gene therapy for neurological disorders by limiting delivery of viral vectors, nanoparticles, and biologics to the central nervous system. Multiple strategies have been developed to transiently disrupt or bypass the BBB, including focused ultrasound (FUS) with microbubbles, osmotic agents, biochemical modulators, and receptor-mediated transport systems. Among these approaches, FUS-mediated BBB opening has emerged as the most spatially precise and clinically advanced strategy. Methods: This narrative review synthesizes recent preclinical and clinical literature on BBB microdisruption technologies for central nervous system gene therapy, with primary emphasis on FUS combined with microbubbles. We review BBB physiology, gene delivery platforms, the development of FUS technologies, optimization parameters, and translational evidence across neurological diseases from animal models through early-phase human studies. Results: FUS-mediated BBB opening has emerged as the leading method for transient barrier modulation. Preclinical studies in Parkinson’s disease, Alzheimer’s disease, Huntington’s disease, glioblastoma, amyotrophic lateral sclerosis, and lysosomal storage disorders demonstrate enhanced gene delivery, increased transgene expression, and improved functional outcomes. Large-animal studies and early clinical trials indicate that BBB opening is reversible, spatially controlled, and generally well tolerated. Clinical investigations have demonstrated successful delivery of therapeutic agents across neurological indications, with preliminary efficacy signals including improved drug penetration, metabolic changes, and potential survival benefits. Optimization of acoustic parameters, microbubble characteristics, and real-time cavitation monitoring remains critical for maximizing safety and therapeutic efficacy. Conclusions: BBB microdisruption, particularly through FUS with microbubbles, represents a transformative platform for central nervous system gene therapy. Continued research is needed to standardize treatment protocols, characterize long-term safety, and facilitate broader clinical translation. Full article

Mineral-scale deposition remains a persistent flow-assurance and asset-integrity constraint in oil and gas production. Calcium carbonate, calcium sulfate, barium sulfate, iron sulfide, and mixed inorganic scale deposits reduce tubing internal diameter. They also impair near-wellbore permeability, block safety-critical valves, reduce heat-transfer efficiency, and intensify under-deposit corrosion. Conventional management relies on prediction, chemical inhibition, squeeze treatments, acid dissolution, chelation, mechanical scraping, milling, jetting, and operational water management. These methods are indispensable, but each has a restricted operating envelope. Key limitations include mineral selectivity, corrosion risk, environmental discharge, intervention cost, debris generation, and poor effectiveness against chemically resistant sulfate scales, particularly BaSO₄. Ultrasound has therefore attracted interest as a non-chemical technology. Acoustic cavitation, microstreaming, pressure oscillation, mechanical vibration, and micro jetting may suppress nucleation, disturb boundary layers, weaken adhesion, and fragment brittle deposits. This review critically evaluates ultrasound-assisted scale prevention and removal, with emphasis on production tubing and oilfield relevance. Existing studies show credible mechanistic plausibility and promising laboratory performance for CaCO₃, CaSO₄/gypsum, KCl, NaCl, and membrane or heat-transfer fouling systems. It also compares performance metrics, field cases, and technology-readiness barriers. The evidence is less mature for long steel tubulars operating under high-pressure, high-temperature, multiphase production conditions. Current evidence positions ultrasound at technology-readiness level (TRL) 3–4 for CaCO₃ and CaSO₄ systems, where laboratory and bench-scale validation is established, and at TRL 2–3 for BaSO₄, where mechanistic plausibility exists but controlled experimental validation remains absent. The technology is not yet at the pilot–production transition for downhole tubing applications, but it is approaching that threshold for surface process equipment. Its most credible near-term role is as an intensifier paired with low-dose chemical inhibitors, where acoustic boundary-layer disruption can reduce the minimum inhibitory concentration threshold of inhibitors, and with mild chelating agents for early-stage BaSO₄ management, where ultrasound-enhanced mass transfer may accelerate chelant penetration into deposit microstructure. Advancing ultrasound from its current TRL toward field qualification requires targeted BaSO₄ scale validation in steel tubing systems, acoustic field mapping under HPHT multiphase conditions, mass-removal metrics, and a structured pilot programme. Full article

Hard and brittle material components with complex curved surfaces are widely used in critical foundational parts within aerospace, optoelectronics, and other fields. Their machining quality directly determines the performance and reliability of high-end equipment. However, the inherent properties of hard and brittle materials make them prone to surface/subsurface damage during traditional polishing processes, and maintaining the form accuracy of complex curved surfaces is challenging. Although abrasive waterjet polishing enables non-contact flexible processing, its energy efficiency is low. Additionally, although ultrasonic-assisted polishing can improve material removal, its spatial localization is insufficient, limiting energy utilization efficiency. To address these issues, this paper proposes a novel method of focused, ultrasonic, vibration-assisted abrasive waterjet polishing. The influence of the radiation force and cavitation force of the focused ultrasonic field on abrasive particle motion is analyzed, and analytical equations for abrasive particle velocity are established. Subsequently, single-factor and response surface methodologies are employed to systematically evaluate the influence of process parameters on machining quality and efficiency. The material removal process during FUAP involves both plastic shearing/chip formation and localized brittle fracture. Focused ultrasonic assistance promotes micro-cutting and plastic shearing, while localized crushing pits indicate that brittle fracture remains non-negligible. The focused ultrasound superimposes alternating stress onto the impact action, mitigating microscale crushing pit defects during the brittle removal process of monocrystalline silicon. Furthermore, appropriately increasing ultrasonic power, enlarging abrasive particle size, and raising abrasive concentration all contribute to enhanced material removal from monocrystalline silicon. Adjusting the nozzle height to the effective region of the focused ultrasonic energy field promotes material removal via chip formation while avoiding pit defects caused by excessive fracture. These results suggest that focused ultrasonic energy can be effectively integrated into abrasive waterjet polishing to enhance material removal while suppressing brittle surface defects, thereby offering a promising strategy for the ultra-precision finishing of hard and brittle components with complex curved surfaces. Full article

Ultrasound technology has emerged as a promising non-thermal approach for modifying the structural and functional properties of food matrices. However, its impact on starch digestibility remains insufficiently understood, particularly in complex systems such as cereal, legume, and pseudocereal flours. This study evaluated the effect of power ultrasound on the functional properties and in vitro digestibility of durum wheat (DWF), chickpea (CF), and amaranth (AF) flours. Flours were treated using an ultrasonic probe (20 kHz, 60% amplitude) for 10 and 20 min while maintaining the sample temperature at 15 °C. Structural and functional properties were assessed, including color, morphology, water absorption, FT-IR spectra, pasting behavior, thermal properties, and starch fractions. Ultrasound induced structural modifications, including starch granule disruption and increased surface roughness. Lightness increased in DWF, CF, and AF, although the magnitude of the response differed among flour types. Water absorption improved in DWF but decreased in CF and AF. FT-IR spectra suggested molecular rearrangements, while viscoelastic and thermal analyses showed increased viscosity in DWF and CF and reduced viscosity in AF. Ultrasound also modified starch fractions and in vitro starch digestibility in a flour-dependent manner, reflecting the distinct structural responses of cereal, legume, and pseudocereal starches to acoustic cavitation. Overall, ultrasound modified the functionality of flour and starch digestibility in a matrix-dependent manner, supporting its potential as a clean-label technology for tailoring the functional properties of different flour matrices. Full article

Focused ultrasound (FUS) comprises a diverse group of non-invasive, non-ionizing acoustic technologies that have evolved from tools for localized tissue destruction into platforms capable of influencing complex biological processes. In oncology, growing evidence suggests that the effects of focused ultrasound extend beyond direct tumor treatment to include modulation of the tumor microenvironment and anti-tumor immunity. This review examines the major FUS modalities currently under investigation for cancer therapy, including high-intensity focused ultrasound (HIFU), intrinsic threshold histotripsy, boiling histotripsy, shock-scattering histotripsy, and low-intensity focused ultrasound (LIFU), with emphasis on the distinct physical mechanisms that underlie their biological effects. Although these modalities differ in how they interact with tissue, they share the capacity to alter tumor biology through changes in antigen availability, inflammatory signaling, and immune cell activity. These responses have been associated with enhanced immune recognition of tumors, remodeling of immunosuppressive microenvironments, and improved therapeutic responsiveness in preclinical and emerging clinical studies. As interest in focused ultrasound continues to expand, understanding the relationship between modality-specific bioeffects and downstream immune outcomes has become increasingly important. Collectively, the literature highlights focused ultrasound as a versatile therapeutic platform capable of linking precise local intervention with broader biological and immunological consequences, supporting its continued development as both a tumor-directed and immune-modulating strategy in cancer therapy. Full article

Ultrasound-induced cavitation is conventionally described through nonlinear bubble dynamics, acoustic pressure modulation, microbubble oscillation or collapse, local mechanical stress, thermal or chemical activation, and subsequent biological effects. In medical contexts, such cavitation-mediated processes are increasingly relevant to sonoporation, microbubble-enhanced drug delivery, sonodynamic therapy, and histotripsy. However, a compact phenomenological framework linking measurable cavitation dynamics to delayed, channel-specific biological outputs remains useful, particularly when different endpoints such as membrane permeabilization, reactive oxygen species generation, molecular uptake, and tissue fragmentation are considered together. In this work, a phenomenological relational–informational bridge model is proposed, in which therapeutic cavitation is interpreted as biological constraint focusing. The cavitation region and its adjacent biological microenvironment are represented as a localized, acoustically driven subsystem whose effective constraint state changes during bubble or microbubble oscillation and collapse. Bubble oscillation or collapse is represented as a rapid increase in constraint loading and informational action density, whereas medically relevant effects are modeled as relaxation of a transient high-tension state into bioactive output channels, including membrane permeabilization, reactive oxygen species generation, molecular delivery, and mechanical tissue fragmentation. The model couples the bubble or microbubble radius R(t) and collapse or oscillation velocity $\dot{R}\left(t\right)$, obtained experimentally or from Rayleigh–Plesset-type dynamics, to a dimensionless relational constraint parameter λ(t), an informational action density ${\mathcal{S}}_{rel}\left(t\right)$, a stored high-tension reservoir $E_{rel}\left(t\right)$, channel-specific motif populations $N_k\left(t\right)$, and measurable biological outputs $B_k\left(t\right)$. The construction is not intended to replace hydrodynamic, thermodynamic, sonochemical, or biomechanical models; rather, it provides a latent-variable layer that may organize how cavitation loading is converted into endpoint-specific biological responses. The framework yields testable expectations: biological response should correlate not only with acoustic pressure or minimum bubble radius, but also with the rate of constraint loading, reservoir buildup and depletion, relaxation-channel kinetics, and modifiers such as microbubble composition, tissue context, oxygenation, sonosensitizer availability, and molecular cargo. Ultrasound-mediated cavitation is therefore reframed as a bioengineering process in which acoustic exposure, bubble dynamics, transient energy localization, and biological endpoint formation are connected through a testable phenomenological bridge model. Full article

This study aimed to evaluate the efficacy of crude polysaccharide extraction from Thai-cultivated oats (Avena sativa L.) utilizing hot water extraction (HW) and ultrasound-assisted water extraction (UW) methods. Optimal conditions were determined by a response surface methodology (RSM). The influence of solid-to-liquid ratio, temperature or %amplitude, and extraction time on %yield and beta glucan content was investigated. Under optimal conditions, UW produced a superior %yield (82.72 ± 2.19%) and beta glucan content (1.75 ± 0.87 g/100 g extract) compared to HW (41.32 ± 0.98% and 1.25 ± 0.27 g/100 g extract). This finding may occur from acoustic cavitation, which effectively dismantles the cellular wall structure, supported by FTIR analysis finding more distinct β-glycosidic linkage peaks. SEM analyses indicated a greater surface area dispersion and porosity in UW extract relative to HW extract. Analysis of monosaccharide composition supported the properties of both crude extracts, demonstrating glucose as the predominant component. However, the functional and bioactive characterization demonstrated a distinct trade-off between the two extraction methods. HW extract demonstrated superior swelling capacity (6.2 vs. 2.7 g/g at pH 6.5), enhanced antioxidant activity compared to both ABTS (0.67 ± 0.04 vs. 0.58 ± 0.06 μmol TE/g), DPPH (0.53 ± 0.06 vs. 0.35 ± 0.06 μmol TE/g), and FRAP (0.05 ± 0.02 vs. 0.03 ± 0.01 μmol TE/g), total phenolic content (98.33 ± 7.68 vs. 87.79 ± 3.07 mg GAE/g). The crude extracts from the two methods had selective enzyme inhibitory activity, exhibiting considerable inhibition of α-glucosidase and markedly reduced inhibition of α-amylase. UW demonstrated slightly superior inhibitory activity compared to HW for both enzymes. The findings indicate that the determination of crude polysaccharides should principally take into account the purpose of the final product. UW is preferable for optimizing %yield and beta glucan content. Nevertheless, if the emphasis is on functional attributes like water absorption and antioxidant efficacy, HW has advantages that merit a consideration. This research provides a framework for identifying optimal extraction methods aimed at extracting crude polysaccharides from Thai-cultivated oats for use as a functional ingredient in health food products. Full article

Shell-and-tube heat exchangers often operate under harsh conditions that induce fouling, leading to loss of thermal efficiency, production downtime, and increased maintenance costs. Conventional cleaning procedures generally require scheduled or unscheduled shutdowns, with direct operational and financial impacts. In this context, ultrasonic cavitation has been investigated as a strategy for fouling prevention and equipment cleaning, with the potential to reduce cleaning downtime or support in-service mitigation strategies. This work presents the development of an acquisition platform based on a miniaturized, waterproof acoustic probe designed for operation inside 8 mm tubes under cavitating ultrasonic fields, with the goal of experimentally mapping the relative acoustic response amplitude and dominant frequency in U-tube heat exchangers. The system integrates a piezoelectric sensing element embedded in protective encapsulation, signal-conditioning electronics, and a high-sampling-rate acquisition module. Experiments were conducted in a reduced-scale exchanger comprising 90 access ports and measurement depths up to 775 mm, using 28 kHz ultrasonic transducers. The probe successfully captured both the spectral content and the spatial variation of the voltage-based acoustic response along the tube bundle, revealing position-dependent amplitude variations and dominant-frequency measurements concentrated around the imposed excitation frequency. The analysis supported the definition of a reduced set of representative sampling locations, decreasing acquisition time while preserving the main spatial trends relevant to the objectives of this study. The procedures established here provide an experimental basis for future studies on the application of ultrasound to fouling-mitigation strategies in industrial thermal systems. Full article

The pine wood nematode Bursaphelenchus xylophilus (Nickle, 1970) is one of the most damaging pests affecting coniferous forests, prompting the European Union to adopt strict measures to limit its spread. In sawmills, wood is typically heat-treated following the International Standard for Phytosanitary Measures No. 15 (ISPM 15, 2019), which recommends heat treatment or fumigation with methyl bromide or sulfuryl fluoride for wood packaging materials including pallets, crates, and dunnage. To investigate safer and more cost-effective alternatives, this study uses ultrasound technology as a potential control method. Ultrasound, defined as high-frequency sound waves beyond human hearing, generates acoustic cavitation capable of damaging biological tissues. Nematodes were exposed to ultrasound both in vitro and within artificially inoculated green wood blocks (50 × 50 × 50 mm). In vitro tests showed significant reductions in viability at the measured time points (15, 30, 45 min), with complete mortality observed at 45 min. In wood blocks, nematode numbers declined progressively across the measured intervals, with linear regression providing a model-based estimate of complete elimination before approx. 80 min, although this was not experimentally verified. These results demonstrate that the use of ultrasound at 40 kHz reduces nematode survival under both laboratory conditions and wood matrix conditions. Full article

High-frequency ultrasound-assisted activation of peracetic acid (PAA) was investigated as a tunable advanced oxidation process for the removal of organic pollutants from water. Sunset Yellow FCF (SSY), a representative anionic azo dye, was used as a probe contaminant in a 425 kHz sonoreactor to clarify the roles of PAA speciation, acoustic cavitation, dissolved gases, oxidant dose, acoustic power, and initial pH. UV spectroscopic analysis showed that PAA exhibits pH-dependent far-UV absorbance associated with acid-base speciation and peroxide equilibria, while ultrasonication promoted simultaneous PAA activation and H₂O₂ accumulation. Compared with PAA alone and ultrasound alone, the combined US/PAA process markedly enhanced SSY decolorization. Under natural conditions, 5 mg/L SSY and 5 mM PAA were completely decolorized within 210 min, with an initial rate of 0.116 mg/L·min, compared with 0.078 and 0.0086 mg/L·min for ultrasound and PAA alone, respectively. The corresponding synergy ratio and synergy index were 1.5 and 1.34. The process exhibited tunable reaction-pathway control, with two favorable pH windows: a strongly acidic region, where interfacial HO^•-driven sonochemistry and PAA stability are favored, and a mildly alkaline region, where PAA deprotonation promotes peracetate-driven acyl/peroxyl radical-chain propagation. Oxygen saturation improved performance, whereas CO₂ suppressed cavitation-driven activation. Increasing PAA concentration and acoustic power enhanced removal up to practical limits, beyond which radical scavenging and diminishing sonochemical returns became evident. Beyond demonstrating enhanced decolorization, this study distinguishes US/PAA from previously reported UV/PAA, transition-metal/PAA, and ultrasound-only systems by showing how 425 kHz cavitation converts PAA into a tunable hybrid HO^•/acyl–peroxyl radical network. The main contribution is a mechanistic operating map that links PAA speciation, sonochemical peroxide accumulation, dissolved gas chemistry, acoustic power, oxidant dose, and pH to pollutant-removal performance, thereby defining practical windows for sono-activated PAA treatment of anionic dyes and related recalcitrant contaminants. Full article