Ultrasound Intensity Research Articles

Ultrasound-Assisted Extraction of Blackberry Seed Oil: Optimization and Oil Characterization

Ultrasound-assisted extraction (UAE) was applied to extract oil from blackberry (BB) seeds. The effect of UAE conditions on oil recovery and quality was investigated. Favorable experimental conditions (ultrasound intensity (UI), extraction temperature, and time) were investigated using response surface methodology (RSM). A Box-Behnken design was used to predict optimized conditions for BB seed oil extraction. These conditions were as follows: 13.77 W/cm2 UI, 45 °C extraction temperature, and 15 min extraction time. The experimental value obtained for extraction efficiency under optimal conditions was 87 ± 0.34%, in good agreement with the optimized predicted value. UAE does not affect the oil composition and confers higher antioxidant values in BB seed oil in comparison with Soxhlet extraction.

Influence of ultrasound intensities on colour, oxidative stability, and texture of Longissimus lumborum steaks from Nellore cattle

SummaryThis research aimed to evaluate the influence of different high‐intensity ultrasound (HIU) levels (control: 0; low: 276.36; moderate: 422.67; and high: 747.79 W cm−2) and stored in aerobic conditions for 7 days at 4 ± 1 °C on instrumental colour, metmyoglobin reducing activity (MRA), oxidative stability and texture of Longissimus lumborum (LL) from Nellore (Bos indicus) cattle. HIU moderate level samples exhibited higher (P < 0.05) lipid and protein oxidation, whereas high level showed higher MRA than control, low and moderate level counterparts. An increase (P < 0.05) of hue angle, MRA, lipid, and protein oxidation during refrigerated storage. Overall, the HIU levels did not influence pH, colour, texture, lipid, and protein oxidation, whereas HIU high level (HIU‐HL) improved the MRA contributing to beef colour stability.

Technology development for acoustic hemostasis

In trauma cases, the often immediate (and necessary) requirement is to stop uncontrolled bleeding; indeed, in combat, more than 50% of deaths result from exsanguination. With the development of ultrasound image-guided High Intensity Focused Ultrasound (HIFU) devices, “Acoustic Hemostasis” is not only possible but has the ability to terminate uncontrolled bleeding as well as for many applications of considerable benefit to medicine. In this lecture, various technology development devices and methodologies will be described that have the potential for commercial development for a wide variety of medical indications.

Ultrasound multifrequency strategy applied to the estimation of lung surface roughness

There exist lung pathologies (e.g., COPD) characterized by an enlargement of air-spaces. Since air-spaces of different sizes can generate different levels of roughness along the lung surface, estimating the roughness may provide an indirect characterization of the lung state. This study, thus, analyzes the possibility to develop a multi-frequency quantitative approach forthe estimation of lung surface roughness. Specifically, the presented technique focuses on the analysis of ultrasound image intensity variation along the lung surface as a function of frequency. In silico and in vitro results will be presented. First, k-wave was used to study the effect of different levels of lung surface roughness on numerically generated ultrasound images. Data were simulated with center frequencies from 1 to 10 MHz (bandwidth = 0.5 MHz). The same acquisition strategy was then used to acquire data from 3D printed steel models, made to mimic an acoustic interface with high reflection coefficient (similar to air-tissue interfaces) and realized with different levels of roughness. As expected, due to diffuse scattering, the increase of the “air-spaces” diameter is linked to a decrease of the frequency at which a significant drop of intensity was observed. This ultimately provides a way to indirectly estimate lung source roughness.

Structural and functional properties of self-assembled peanut protein nanoparticles prepared by ultrasonic treatment: Effects of ultrasound intensity and protein concentration

Peanut protein isolate (PPI) nanoparticles were prepared by self-assembly under the combined action of ultrasound (US) and protein concentration. The effects of ultrasound intensity (150–500 W) and protein concentration (1–12 %, w/v) on the structural and functional properties of PPI nanoparticles were investigated. Low-intensity US significantly increased the particle size of PPI, but high-intensity US decreased it. The largest PPI nanoparticles were obtained when 10 % PPI was subjected to low-intensity US treatment (200 W for 5 min). These nanoparticles possessed unique structural characteristics, such as the lowest absolute ζ-potential and the highest contents of exposed free sulfhydryl and disulfide bond, which may be responsible for their excellent heat-set gelling properties. The 12 % PPI treated with low- and high-intensity US had the highest emulsifying activity index and emulsifying stability index, respectively. The self-assembled PPI nanoparticles induced by US treatments at high protein concentrations have great potentials for application in the food industry.

Modeling of Ultrasound Stimulation of Adolescent Pancreas for Insulin Release Therapy.

Our previous published studies have focused on safety and effectiveness of using therapeutic ultrasound (TUS) for treatment of type 2 diabetes mellitus (T2DM) in preclinical models. Here we present a set of simulation studies to explore potential ultrasound application schemes that would be feasible in a clinical setting. Using the multiphysics modeling tool OnScale, we created two-dimensional (2D) models of the human abdomen from CT images captured from one normal weight adolescent patient, and one obese adolescent patient. Based on our previous studies, the frequency of our TUS was 1MHz delivered from a planar unfocused transducer. We tested five different insonation angles, as well as four ultrasound intensities combined with four different duty factors and five durations of application to explore how these variables effect the peak pressure and temperature delivered to the pancreas as well as surrounding tissue in the model. We determined that ultrasound applied directly from the anterior of the patient abdomen at 5W/cm2 delivered consistent acoustic pressures to the pancreas at the levels which we have previously found to be effective at inducing an insulin release from preclinical models. Our modeling work indicates that it may be feasible to non-invasively apply TUS in clinical treatment of T2DM.

Viability variation of T-cells under ultrasound exposure according to adhesion condition with bubbles.

Although cellular immunotherapyis expected as a newcancer treatment, its therapeutic efficiency is limited in solid tumors,because most cells return to the bloodstream rather than adhere to the target site. Therefore, we are motivated to develop a technique to concentrate the cells in the blood flowusing active control of bubble-surrounded cells under ultrasound exposure considering both aspects of cell controllability and viability. We prepared a lipid bubble conjugating ligand to adhere to the surface ofthe T-cells. First, we evaluated the cellcontrollability by retaining the cells on a wall of an artificial blood vesselthrough continuous ultrasound exposure.Next, we investigated the cell viability under ultrasound exposure in a suspension with various bubble concentrations. We estimatedthe concentration of bubbles when the adhesion to the cell surface was saturated.Then,we evaluated the cell viability with various conditions of ultrasound exposure and bubble concentrations.However, it was confirmed that cell damage occurred under conditions that achieved proper control of the cells. Therefore, we exposed the cells to burst waves to reducethe applied ultrasound intensity. Consequently, the significant increase in cell viability wasconfirmed to be inversely proportional to the duty ratio. To retain cellson a vessel wall, determining the appropriate ultrasound condition including sound pressure and waveform is importantto maintain cellviability.

The Impact of High-Intensity Ultrasound-Assisted Extraction on the Structural and Functional Properties of Hempseed Protein Isolate (HPI).

Hempseed protein has become a promising candidate as a future alternative protein source due to its high nutritional value. In the current study, hempseed protein isolate (HPI) was obtained using ultrasonic-assisted extraction with the aim to improve the functionality of HPI via protein structure modification. The solubility of HPI could be improved twofold under 20 kHz ultrasound processing compared to conventional alkaline extraction-isoelectric point precipitation. The protein solubility was gradually enhanced as the ultrasonic power improved, whereas excessive ultrasound intensity would cause a decline in protein solubility. Ultrasonic processing was found to have beneficial effects on the other functionalities of the extracted HPI, such as emulsifying and foaming properties. This improvement can be ascribed to the physical effects of acoustic cavitation that changed the secondary and tertiary structures of the protein to enhance surface hydrophobicity and decrease the particle size of the extracted protein aggregates. In addition, more available thiols were observed in US-treated samples, which could be another reason for improved functionality. However, the results of this study also revealed that prolonged high-power ultrasound exposure may eventually have a detrimental impact on HPI functional properties due to protein aggregation. Overall, this study suggests that high intensity ultrasound can enhance the functionality of HPI, which may ultimately improve its value in HPI-based food products.

Application of Response Surface Method in Pulsed Ultrasound-Assisted Extraction of Complex Plant Materials—A Case Study on Cannabis sativa L.

The purpose of this study was to optimize the effect of particle size, time and ultrasonic intensity on the extraction of phenolic compounds and energy efficiency. Sonication was performed with a VC750 Sonics processor at the following amplitudes: 30, 50 and 70%, which corresponds to the ultrasonic intensity, respectively: 1.6; 5.1 and 8.6 W∙cm−2. The frequency of ultrasound was 20 kHz. Extraction was carried out in a 5 s on–10 s off pulse system. The content of polyphenols and their antioxidant activity were assayed by the spectrophotometric method. Response surface methodology (RMS) was used to optimize the investigated variables. On the basis of the developed model, the highest polyphenols yield was obtained under the following extraction conditions (particle size 0.65 mm, extraction time 13.14 min, ultrasound intensity 6.92 W∙cm−2, which resulted in a maximum value of 15.24 mg GAE∙g−1 dry matter of hemp. Taking into account the lowest unit energy consumption, the best conditions were obtained for particle size of approx. 0.5 mm, extraction time 7.7 min, and ultrasound intensity 1.8 W∙cm−2, which resulted in a phenolic yield of 10.14 mg GAE∙g−1 dry matter of hemp. The best agreement between values of optimization variables within investigated criteria was obtained for the variable particle size. The developed models of pulsed ultrasound-assisted extraction can be used for obtaining polyphenols from Cannabis sativa L. at low unit energy consumption.

Comparison of multifidus muscle intramuscular fat by ultrasound echo intensity and fat-water based MR images in individuals with chronic low back pain

PurposeThe aim of this observational cross-sectional study was to examine correlations of intramuscular fat content in lumbar multifidus (LM) by comparing muscle echo intensity (EI) and percent fat signal fraction (%FSF) generated from ultrasound (US) and magnetic resonance (MR) images, respectively. MethodsMRI and US images from 25 participants (16 females, 9 males) selected from a cohort of patients with chronic low back pain (CLBP) were used. Images were acquired bilaterally, at the L4 and L5 levels (e.g., 4 sites). EI measurements were acquired by manually tracing the cross-sectional border of LM. Mean EI of three US images per site were analyzed (e.g., raw EI). A correction factor for subcutaneous fat thickness (SFT) was also calculated and applied (e.g., corrected EI). Corresponding fat and water MR images were used to acquire %FSF measurements. Intra-rater reliability was assessed by intraclass coefficients (ICC). Pearson correlations and simple linear regression were used to assess the relationship between %FSF, raw EI and corrected EI measurements. ResultsThe intra-rater ICCs for all measurements were moderate to excellent. Correlations between %FSF vs. raw EI and corrected EI were moderate to strong (0.40 < r < 0.52) and (0.40 < r < 0.51), respectively. Moderate correlations between SFT and EI were also identified. ConclusionUS is a low-cost, non-invasive, accessible, and reliable method to examine muscle composition, and presents a promising solution for assessing and monitoring the effect of different treatment options for CLBP in clinical settings.

Kinetics of fibrin clots destruction under ultrasonic cavitation

We studied the kinetic features of fibrin clot destruction in vitro under the action of ultrasonic cavitation generated by low-frequency (36 kHz) ultrasound (US) with the intensity I0 of 4.4–51.2 W/cm2, using a flexible waveguide concentrator. It was established that the rate of US destruction of clots immersed in saline at the initial stage of the process is proportional to I0 in the range of 12–51 W/cm2, corresponds to first-order kinetics, and is determined by the erosive processes without the formation of D-dimers and other fibrinolysis products at a minimum contribution of sonochemical reactions. The clot destruction rate is maximum at the initial time moment and decreases with increasing the US exposure duration (by 35 % in 1 min and by 72 % by the end of the second minute at I0 = 51.2 W/cm2). It was shown that in order to increase the completeness of clot destruction at a minimum administered US dose, it is advisable to minimize the US exposure time when using the highest values of the US intensity limited by the level of safe cavitation exposure to the vascular wall, hemostasis, and blood cells.

A chemometric approach to evaluate the effects of probe-type ultrasonication on the enzyme inactivation and quality attributes of fresh amla juice.

The enzymatic browning induced in amla juice due to the high activity of polyphenol oxidase (PPO) and peroxidase (POD) is one of the critical issues faced by the industry. The present study assessed the suitability of non-thermal, high-intensity ultrasound (US) on the inactivation of PPO and POD in fresh Indian Gooseberry juice. Ultrasonic waves, using a 6mm titanium alloy probe were irradiated in the juice at a maximum power of 455W and frequency of 20kHz. The subsequent effects on biochemical attributes were studied using response surface methodology. Inactivation rates of 90.72% and 73.18%, respectively, for PPO and POD enzymes, were observed at the highest US intensity and exposure time. Numerical optimisation using the three-factor, three-level Box-Behnken design suggested that an optimum process at 70% (energy density: 1610 Wcm-2) pulsed at 5s on and 5s off for 7min 30s resulted in PPO and POD inactivation of the order of 76.42% and 64.57% respectively. At these experimental conditions, the optimized levels of biochemical attributes i.e., ascorbic acid (738.50mg/100mL), total phenols (17.10mg/mL), DPPH antioxidant activity (58.47%), tannins (7.11µg/mL), colour change (ΔE=9.04) and flavonoids (6.14mg/mL) were achieved. The overall statistical models were significant for all the responses except for reducing sugars. Furthermore, the approximation equations for individual responses indicated that the goodness of fit was adequate (R2>0.90). The results suggested that ultrasound is a suitable processing technique for amla juice stabilisation compared to thermal treatments that result in the loss of quality.

Investigating the Effect of Ultrasound Intensity on the Magnetic Properties of Magnetite Nanostructures Synthesized by Sonochemical Method

Investigating the Effect of Ultrasound Intensity on the Magnetic Properties of Magnetite Nanostructures Synthesized by Sonochemical Method

Secondary ultrasonic atomisation mechanisms

Liquid atomisation is the basis for various practical applications such as pharmaceuticals, cosmetics, food industry, etc. In this case, the main challenge is the development of high-performance, highly dispersed atomisation systems. Generally, high-throughput atomisation systems form aerosol with large droplet sizes, and high-disperse atomisation systems have low performance. Secondary ultrasonic atomisation can solve this problem by allowing non-contact crushing of already formed aerosol droplets with large droplet sizes by means of a high-intensity ultrasonic field. For this purpose, a pre-generated stream of liquid droplets is directed into a cylindrical region formed by an emitter in which a high-intensity ultrasonic field is generated. Ultrasonic radiator, is a tube of stepped-variable cross-section, providing the formation of bending-diametral or diametral oscillations at a frequency above 20 kHz. At sufficiently high ultrasound intensity, conditions for further crushing of liquid droplets are realised, which leads to the formation of a highly dispersed aerosol. This paper describes the proposed mathematical model of the atomisation process and finds the regularities of the process depending on the determining parameters of the ultrasonic field and physical and chemical properties of the liquid. Two mechanisms of jet destruction are revealed: direct destruction of droplets when they hit the ultrasonic wave front and cavitation mechanism of droplet and jet destruction. The dominant crushing mechanism depends on the problem parameters and, in turn, determines the minimum size of the resulting droplets. The results of this work will help to optimise the secondary ultrasonic atomisation process and improve liquid atomisation technologies in various applications.

Application of Different Stimuli-Responsive Polymeric Micelles for Drug Release

Achieving controlled release of drugs in disease treatment can greatly improve the utilization rate and therapeutic effect of drugs. Therefore, the development of functional materials with controllable drug release has received more and more attention, such as stimuli-responsive polymeric micelles. The so-called stimuli-responsive polymeric micelles are a new type of polymer micelles that can be used to give responses to different stimulus conditions, such as endogenous stimuli (e.g. light, temperature, ultrasound intensity, magnetic field or electric field) and exogenous stimuli (e.g. redox potential, pH, or enzyme concentration). They can exhibit distinctive size and stability with the variations of the endogenous or exogenous environment. Stimuli-responsive polymeric micelles have several desirable biotechnology applications including their potential use as drug delivery vehicles because tumor tissue and normal tissue is different in physical and chemical properties, where they are very sensitive to endogenous or exogenous environmental changes. This research would mainly discuss different stimuli-responsive polymeric micelles for developing a diverse of drug delivery systems, including light and magnetism response, temperature and ultrasound response, redox response, pH response and enzyme response. Some recent advances and future directions would be briefly referred to as well.

Influence of ultrasonic-microwave power on the structure and in vitro digestibility of lotus seed starch-glycerin monostearin complexes after retrogradation

The digestibility of starches with high amylose content can be modulated by the complexation with lipids, which is largely influenced by physical modification methods. In the current work, the impact of ultrasound-microwavre synergistic treatment on the structure and in vitro digestibility of lotus seed starch-glycerin monostearin complexes (LS-GMSc) after retrogradation were investigated. Results showed that 400 W of ultrasound treatment combined with microwave was more conducive to the formation of LS-GMSc, which increased the microcrystalline region and ordering degree of starch. However, excessively high ultrasound intensity weakened V-type diffraction and promoted amylose recrystallization. Investigation of the micromorphology and thermal properties revealed that the existence of V-complexes retarded starch retrogradation, and this effect was significantly enhanced after appropriate ultrasound (400 W) treatment. The digestion showed that 400 W of ultrasound treatment improved the digestive resistance of starch complexes and increased the content of resistant starch. These results are significant to the theoretical foundation and functional application of V-type complexes on anti-gelling and anti-digestion.

Methylene Blue Delivery Mediated by Focused Ultrasound-Induced Blood-Brain Barrier Disruption Reduces Neural Damage and Amyloid-Beta Plaques by AQP-4 Upregulation.

Alzheimer's disease (AD) is the most prevalent neurodegenerative disease worldwide, causing progressive cognitive decline, memory impairment, and neurological deficits. Methylene blue (MB), an antioxidant, has emerged as a potential drug for the treatment of AD owing to its cognitive improvement and neuroprotective functions. Despite the small molecular size of MB, which can cross the BBB, the therapeutic effective dosage using a BBB-permeable delivery system in a specific brain localization remains unclear. In this study, we presented magnetic resonance-guided focused ultrasound (MRgFUS) as a delivery system to enhance BBB permeability for the effective treatment of AD. MRgFUS using two ultrasound intensities (0.25 and 0.32 MPa) was used to intravenously deliver MB to the hippocampal region. Compared with treatment with 0.25 MPa FUS, treatment with 0.32 MPa FUS significantly enhanced MB brain accumulation. Deposition of amyloid-β (Aβ) plaques and neural cell damage was significantly reduced in 0.32 MPa FUS/MB-treated APP/PS1 mice. Furthermore, aquaporin-4 expression increased significantly in the 0.32 MPa FUS and 0.32 MPa FUS/MB groups without glial fibrillary acidic protein activation. The results from this study demonstrate that FUS improved MB delivery to the brain, and FUS/MB combination treatment reduced the number of Aβ plaques. This study revealed the potential of FUS-BBBD as an effective strategy to enhance the efficacy of therapeutic drugs for AD.

Ultrasound-Driven On-Demand Transient Triboelectric Nanogenerator for Subcutaneous Antibacterial Activity.

To prevent surgical site infection (SSI), which significantly increases the rate morbidity and mortality, eliminating microorganisms is prominent. Antimicrobial resistance is identified as a global health challenge. This work proposes a new strategy to eliminate microorganisms of deep tissue through electrical stimulation with an ultrasound (US)-driven implantable, biodegradable, and vibrant triboelectric nanogenerator (IBV-TENG). After a programmed lifetime, the IBV-TENG can be eliminated by provoking the on-demand device dissolution by controlling US intensity with no surgical removal of the device from the body. A voltage of ≈4V and current of ≈22 µA generated from IBV-TENG under ultrasound in vitro, confirming inactivating ≈100% of Staphylococcus aureus and ≈99% of Escherichia coli. Furthermore, ex vivo results show that IBV-TENG implanted under porcine tissue successfully inactivates bacteria. This antibacterial technology is expected to be a countermeasure strategy against SSIs, increasing life expectancy and healthcare quality by preventing microorganisms of deep tissue.

Protein‐Coated Biodegradable Gas‐Stabilizing Nanoparticles for Cancer Therapy and Diagnosis Using Focused Ultrasound

AbstractSurface‐engineered hydrophobic nanoparticles that can stabilize small gas pockets on their surfaces (i.e., gas‐stabilizing nanoparticles, GSNs) have been recently shown to be excellent contrast and cavitation agents for ultrasound theranostics. However, previously developed GSNs are not biodegradable, which limits their clinical translation potential. Here the development of biodegradable GSNs is shown by coating hydrophobically modified mesoporous silica nanoparticles with different protein solutions. It is found that these novel GSNs retain strong cavitation activity while rapidly degrading in simulated body fluid (SBF) or in vivo in days or a few weeks, respectively. Interestingly, GSNs coated with other stabilizing layers, Pluronic F127 polymer or phospholipids, demonstrated significantly slower degradation rates with only partial degradation even after a month of incubation in SBF. Next, it is shown that these biodegradable GSNs can be used to ablate tumor xenografts at lower ultrasound intensities, thus avoiding the side effects of high‐intensity ultrasound. Finally, it is shown that only tumors treated with GSNs and ultrasound can specifically enrich for circulating tumor DNA, which will improve liquid biopsies for understanding tumor heterogeneity and treatment response. Overall, this study details a simple yet effective method for preparing biodegradable GSNs with broad potential for applications in cancer diagnosis and therapy.

Extraordinary Solidification Mechanism of Liquid Alloys Under Acoustic Levitation State.

The acoustic levitation of various materials can be realized by highly intensive ultrasound, which provides a free surface and containerless state for materials processing under space simulation conditions. The nonlinear effects such as acoustic radiation pressure, acoustic streaming, and ultrasonic cavitation open up special access to modulate the fluid dynamics and solidification mechanisms of liquid materials. Here, the physical characteristics of liquid flow, undercooling capability, phase separation, and crystal nucleation and growth within acoustically levitated droplets are explored comprehensively to reveal the extraordinary solidification kinetics of liquid alloys. The sectorial shape oscillations of the 2nd to 10th order modes accompanying internal potential flow are observed for water droplets with modulated ultrasound amplitudes, while the enhanced ultrasound intensity promotes ice nucleation and thus reduces water undercooling. The migration of Sn-rich globules during phase separation of immiscible Al-Cu-Sn alloy is dominated by the droplet deformation and rotation related to acoustic levitation. The high undercooling states of liquid Ag-Cu-Ge and Ni-Sn alloys during acoustic levitation result in the refinement of (Ag) dendrites and the formation of anomalous (Ni+Ni3 Sn) eutectics. The ultrasound-liquid interaction also induces surface waves during the containerless solidification of Ag-Cu and Ni-Sn eutectic alloys.