Explore the vast range of titles available.

Low-intensity focused ultrasound (FUS) has significant potential as a non-invasive brain stimulation modality and novel technique for functional brain mapping, particularly with its advantage of greater spatial selectivity and depth penetration compared to existing non-invasive brain stimulation techniques. As previous studies, primarily carried out in small animals, have demonstrated that sonication parameters affect the stimulation efficiency, further investigation in large animals is necessary to translate this technique into clinical practice. In the present study, we examined the effects of sonication parameters on the transient modification of excitability of cortical and thalamic areas in an ovine model. Guided by anatomical and functional neuroimaging data specific to each animal, 250 kHz FUS was transcranially applied to the primary sensorimotor area associated with the right hind limb and its thalamic projection in sheep (n = 10) across multiple sessions using various combinations of sonication parameters. The degree of effect from FUS was assessed through electrophysiological responses, through analysis of electromyogram and electroencephalographic somatosensory evoked potentials for evaluation of excitatory and suppressive effects, respectively. We found that the modulatory effects were transient and reversible, with specific sonication parameters outperforming others in modulating regional brain activity. Magnetic resonance imaging and histological analysis conducted at different time points after the final sonication session, as well as behavioral observations, showed that repeated exposure to FUS did not damage the underlying brain tissue. Our results suggest that FUS-mediated, non-invasive, region-specific bimodal neuromodulation can be safely achieved in an ovine model, indicating its potential for translation into human studies.

We investigated controlled blood-brain barrier (BBB) disruption using a low-frequency clinical transcranial MRI-guided focused ultrasound (TcMRgFUS) device and evaluated enhanced delivery of irinotecan chemotherapy to the brain and a rat glioma model. Animals received three weekly sessions of FUS, FUS and 10 mg/kg irinotecan, or irinotecan alone. In each session, four volumetric sonications targeted 36 locations in one hemisphere. With feedback control based on recordings of acoustic emissions, 98% of the sonication targets (1045/1071) reached a pre-defined level of acoustic emission, while the probability of wideband emission (a signature for inertial cavitation) was than 1%. BBB disruption, evaluated by mapping the R1 relaxation rate after administration of an MRI contrast agent, was significantly higher in the sonicated hemisphere (P < 0.01). Histological evaluation found minimal tissue effects. Irinotecan concentrations in the brain were significantly higher (P < 0.001) with BBB disruption, but SN-38 was only detected in <50% of the samples and only with an excessive irinotecan dose. Irinotecan with BBB disruption did not impede tumor growth or increase survival. Overall these results demonstrate safe and controlled BBB disruption with a low-frequency clinical TcMRgFUS device. While irinotecan delivery to the brain was not neurotoxic, it did not improve outcomes in the F98 glioma model.

The application of bio-based materials is becoming impellent owing to the increasing demand for alternatives to petroleum-based analogs. In this regard, cellulose nanocrystals (CNCs) with unique properties have received a significant interest, while their hydrophilic character poses a challenge to their commercial applications. Ultrasonication treatment is one of the most commonly used methods to improve CNCs' dispersion in different solvents and polymer matrices. In this work, the effectiveness of ultrasonication treatment in the dispersion of CNCs in a water-soluble polymer (polyvinyl alcohol, PVA) was studied. An aqueous suspension of polyvinyl alcohol and CNCs was prepared using different ultrasonication times and amplitudes. The morphology, particle size and dispersion of CNCs were studied using X-ray diffraction, transmission electron microscopy, and dynamic light scattering. The results indicated that with increase in the sonication amplitude, there was a substantial decrease in nanoparticle length, while long sonication times gently affected the nanoparticle length. Furthermore, improved dispersion was observed in samples prepared using longer sonication time.

This study provides a comprehensive assessment of the effect of direct (probe) and indirect (bath) ultrasound treatments on the physicochemical and structural properties of red bell pepper ( L.) tissue. Ultrasound was applied under controlled conditions to induce structural modification without excessive thermal or mechanical damage. The treated samples were evaluated using chemical (polyphenols, flavonoids, carotenoids, vitamin C, sugars), microbiological (total viable count (TVC) and total yeast and mold count (TYM)), spectroscopic (FTIR, NMR), thermal (TGA), and microscopic (SEM, micro-CT) analyses. Both ultrasound modes affected the tissue, but their effects differed in intensity and character. Direct ultrasound caused stronger cavitation and mechanical stress, resulting in greater cell wall disruption, higher permeability, and enhanced release of bioactive compounds such as polyphenols, vitamin C and antioxidants from the tissue matrix to the surroundings. Indirect ultrasound acted more gently, preserving cellular integrity and sugar profile while moderately increasing antioxidant activity. Cluster and correlation analyses confirmed that ultrasound mode was the main factor differentiating the samples. Short-term direct sonication enhanced the release of antioxidant compounds, whereas prolonged exposure led to their degradation, resulting in an overall decline in antioxidant capacity, and indirect ultrasound better preserved texture and sugar composition. This demonstrates that ultrasound mode and duration can be tailored to balance tissue integrity and enhance bioactive compounds in plant-based materials.

Over 22,000 species of biotically pollinated flowering plants, including some major agricultural crops, depend primarily on bees capable of floral sonication for pollination services. The ability to sonicate (“buzz”) flowers is widespread in bees but not ubiquitous. Despite the prevalence of this pollinator behavior and its importance to natural and agricultural systems, the evolutionary history of floral sonication in bees has not been previously studied. Here, we reconstruct the evolutionary history of floral sonication in bees by generating a time-calibrated phylogeny and reconstructing ancestral states for this pollen extraction behavior. We also test the hypothesis that the ability to sonicate flowers and thereby efficiently access pollen from a diverse assemblage of plant species, led to increased diversification among sonicating bee taxa. We find that floral sonication evolved on average 45 times within bees, possibly first during the Early Cretaceous (100–145 million years ago) in the common ancestor of bees. We find that sonicating lineages are significantly more species rich than nonsonicating sister lineages when comparing sister clades, but a probabilistic structured rate permutation on phylogenies approach failed to support the hypothesis that floral sonication is a key driver of bee diversification. This study provides the evolutionary framework needed to further study how floral sonication by bees may have facilitated the spread and common evolution of angiosperm species with poricidal floral morphology.

Extracellular vesicles (EVs) are nano-sized particles released by various cell types that facilitate intercellular communication by transferring bioactive molecules. Owing to their biocompatibility, EVs are widely used as drug delivery vehicles. However, freezing EVs at – 70 °C can induce aggregation, reducing their effective concentration and drug delivery efficiency. In this study, we evaluated the use of water-bath sonication to disperse aggregated EVs and compared its effectiveness with regular pipetting. Frozen EVs showed reduced total concentration and increased aggregation relative to fresh EVs. Sonication at power level 3 (40 kHz, 100 W) significantly increased EV concentration and reduced aggregation. Unlike pipetting, only sonication effectively dispersed aggregated EVs, though subsequent pipetting caused reaggregation. In vivo, aggregated EVs were detected in the bronchoalveolar lavage fluid of mice treated with frozen EVs, whereas mice receiving sonicated EVs exhibited fewer aggregates and enhanced cellular uptake. Molecular dynamics simulations supported the effectiveness of sonication in dispersing EVs. In conclusion, water-bath sonication is a simple and effective method to restore the functionality of freeze-thawed EVs, improving their intracellular delivery and therapeutic potential.

Boron nitride nanosheets (BNNSs) have gained significant attraction in energy and environment fields because of their two-dimensional (2D) nature, large band gap and high thermal/mechanical performance. However, the current low production efficiency of high-quality BNNSs is still a bottleneck limiting their applications. Herein, based on sonication-assisted liquid-phase exfoliation, we demonstrated a rapid, high-efficient and scalable production strategy of BNNSs and documented the effects of a spectrum of exfoliation factors (e.g., ultrasonic condition, solvent and bulk material feeding) on the yield of BNNSs. A record of yield of 72.5% was achieved while the exfoliated BNNSs have few-layer and defect-free feature. Thanks to the Lewis acid sites of the boron atoms, the BNNSs can interact with the polysulfide anions in liquid electrolyte and also can facilitate the uniform lithium deposition, which finally endow a lithium-sulfur (Li-S) battery with long life. This work provides a facile and rapid strategy for large scale preparation of high-quality BNNSs, also contributes a long-life strategy for dendrite-free Li-S battery, opens new avenues of BNNSs in energy application.

The use of low-frequency (10–60 kHz) ultrasound for enhancement of various biotechnological processes has received increased attention over the last decade as a rapid and reagentless method. Recent breakthroughs in sonochemistry have made the ultrasound irradiation procedure more feasible for a broader range of applications. By varying the sonication parameters, various physical, chemical and biological effects can be achieved that can enhance the target processes in accordance with the applied conditions. However, the conditions that have provided beneficial effects of ultrasound on bioprocesses are case-specific and are therefore not widely available in the literature. This review summarizes the current state of the art in areas where sonochemistry could be successfully combined with biotechnology with the aim of enhancing the efficiency of bioprocesses, including biofuel production, bioprocess monitoring, enzyme biocatalysts, biosensors and biosludge treatment.

Low-intensity, low-frequency ultrasound has shown promise for neuromodulation, particularly for influencing peripheral neural activity. However, the precise parameters required to modulate neuronal activity remain poorly understood, limiting its broader application. Here, we investigated the effects of varying the sonication duration (SD) and duty cycle (DC) on motor neuronal responses in the rat sciatic nerve, with a focus on understanding how cumulative energy exposure influences the activation or suppression of peripheral neural activity during ultrasound neuromodulation. We applied low-intensity, low-frequency ultrasound to the rat sciatic nerve in vivo at different sonication durations and duty cycles. The cumulative energy exposure is calculated as the product of the spatial-peak pulse-average intensity, SD, and DC. Electromyographic (EMG) activity in the gastrocnemius muscle was measured, and the thermal effects were monitored to ensure a non-thermal application. Our findings demonstrate that higher cumulative energy exposure suppresses EMG activity in the gastrocnemius muscle (innervated by the sciatic nerve). However, lower cumulative energy exposure enhances motor stimulation. Notably, the ultrasound-induced EMG changes persisted for 5 min post-sonication – three to five times longer than the application duration – emphasizing the therapeutic potential of ultrasound for precise neural control. Interestingly, our results show a switch from excitation to suppression of electrically evoked EMG activity following ultrasound sonication depending on the acquired cumulative energy. This study establishes a safe parameter space for prolonged neuromodulation, demonstrating its potential for therapeutic applications that can precisely modulate peripheral nervous system activity for treating neuropathies and chronic pain. These findings contribute to the development of ultrasound-based treatments, offering a novel and controllable method for peripheral nerve stimulation.

Graphene nanoplatelets (GNPs) can be produced by exfoliating graphite in solvents via high-power tip sonication. In order to understand the influence of tip sonication parameters on graphite exfoliation to form GNPs, three typical flaked graphite samples were exfoliated into GNPs via tip sonication at power of 60, 100, 200, or 300 W for 10, 30, 60, 90, 120, or 180 min. The concentration of GNP dispersions, the size and defect density of the produced GNPs, and the sedimentation behavior of GNP dispersions produced under various tip sonication parameters were determined. The results indicated that the concentration of the GNP dispersions was proportional to the square root of sonication energy input (the product of sonication power and time). The size and I D / I G values (determined by Raman spectrum) of GNPs produced under various tip sonication powers and times ranged from ~ 1 to ~ 3 μm and ~ 0.1 to ~ 0.3, respectively, which indicated that all the produced GNPs were of high quality. The sedimentation behavior of GNP dispersions showed that the dispersions were favorably stable, and the concentration of each GNP dispersion was ~ 70% of its initial concentration after sedimentation for 96 h. Moreover, the TEM images and electron diffraction patterns were used to confirm that the produced GNPs were few-layer. This study has important implications for selecting the suitable tip sonicating parameters in exfoliating graphite into GNPs.