Ultrasound Intensity Research Articles

Application of Alkaline Deep Eutectic Solvents as a Green Alternative to the Traditional Extractants for the Isolation of Humic Substances.

The presented study focused on the possibility of using alkaline deep eutectic solvents (ADESs) as green extractants for the isolation of humic substances (HSs) from peat and lignite in a process intensified by ultrasound. For this purpose, the extraction procedure was statistically described on the basis of the Box-Behnken design, and the carboxyl group content in the obtained products was optimized due to the ADES composition, ultrasound intensity, and extraction time. For optimal extraction conditions, the experimental carboxyl content in the isolated products was equal to 3.71 and 2.96 mmol g-1 for the HSs extracted from peat and lignite, respectively. These values were similar to the results for the reference samples, which were HSs extracted using 0.1 M NaOH, as well as humic acids and sodium humates purchased from Sigma-Aldrich. The qualitative assessment of the products obtained was based on spectroscopic methods, including FTIR, 1H NMR, and UV-vis. The analyses carried out for the isolated samples revealed the characteristic structures of HSs, including components of aliphatic chains and aromatic core as well as carboxyl, ester, and amino groups. Simultaneously, the results of the spectral ratio of E 280/E 472 showed the significant differences between the relative amount of lignin for the samples tested.

Enhancing efficiency of ultrasound-assisted biodiesel production catalyzed by Eversa® Transform 2.0 at low lipase concentration: Enzyme characterization and process optimization

This study focused on the ultrasound-assisted transesterification of simulated low-quality feedstocks using a low-cost liquid lipase Eversa® Transform 2.0 (ET2). Enzyme characterization was also performed to investigate the effect of ultrasound parameters on enzyme structure. The optimal ultrasound parameters, 40 % amplitude, and 5 % duty cycle effectively enhanced the reaction rate compared to the conventional stirring method while retaining 95 % of the enzyme activity. Analysis of circular dichroism (CD) spectra revealed the preservation of the secondary structure of ET2 under the optimal ultrasound intensities, while fluorescence spectra indicated a slight change in its tertiary structure. The implementation of a two-stage methanol dosing strategy in the ultrasound-assisted reaction effectively mitigated lipase inhibition, yielding a remarkable fatty acid methyl ester (FAME) content of 92.2 % achieved within a 12-h reaction time. Notable, this high FAME content was achieved with only a 4:1 methanol-to-oil molar ratio and a 0.5 wt% enzyme concentration. Under these optimized conditions, the ultrasound-assisted reaction also demonstrated a 15 % improvement in the final FAME content compared to the conventional stirring method. These promising results hold significant potential for advancing the field of biodiesel production via ultrasound technology, contributing substantively to sustainable energy sources.

Synergistic efficacy of ultrasound and ammonium persulfate in inactivating Escherichia coli O157:H7 in buffered peptone water and orange juice

This study investigated the synergistic effects of ammonium persulfate (PS) and ultrasound (US) on the inactivation of Escherichia coli O157:H7 in buffered peptone water (BPW) and orange juice products. A comprehensive assessment of PS concentrations ranging from 1 to 300 mM, considering not only the statistical significance but also the reliability and stability of the experimental outcomes, showed that 150 mM was the optimal PS concentration for the inactivation of E. coli O157:H7. Additionally, US output intensities varying from 30 % to 60 % of the maximum US intensity were evaluated, and 50 % US amplitude was found to be the optimal US condition. A 50 % amplitude setting on the sonicator corresponds to half of its maximum displacement, approximately 60 μm, based on a maximum amplitude of 120 μm. The inactivation level of E. coli O157:H7 was significantly enhanced by the combined treatment of PS and US, compared to each treatment of PS and US alone. In the BPW, a 10-min treatment with the combination of PS and US resulted in a significant synergistic inactivation, achieving up to a log reduction of 3.86 log CFU/mL. Similarly, in orange juice products, a 5-min treatment with the combination of PS and US yielded a significant synergistic inactivation, with a reduction reaching 5.90 log CFU/mL. Although the treatment caused a significant color change in the sample, the visual differences between the treated and non-treated groups were not pronounced. Furthermore, the combined treatment in orange juice demonstrated significantly enhanced antimicrobial efficacy relative to BPW. Despite identical 5-min treatment periods, the application in orange juice resulted in a substantially higher log reduction of E. coli O157:H7, achieving 7.16 log CFU/mL at a reduced PS concentration of 30 mM, whereas the same treatment in BPW yielded only a 2.89 log CFU/mL reduction at a PS concentration of 150 mM, thereby highlighting its significantly superior antimicrobial performance in orange juice. The mechanism underlying microbial inactivation, induced by the combined treatment of PS and US, was identified as significant cell membrane damage. This damage is mediated by sulfate radicals, generated through the sono-activation of persulfate. In addition, the low pH of orange juice, measured at 3.7, is likely to have further deteriorated the E. coli O157:H7 cells compared to BPW (pH 7.2), by disrupting their cell membranes, proton gradients, and energy metabolism. These findings underscore the effectiveness of PS and US integration as a promising approach for non-thermal pasteurization in the food industry. Further research is needed to optimize treatment parameters and fully explore the practical application of this technique in large-scale food processing operations. Sensory evaluation and nutritional assessment are also necessary to address the limitations of PS.

Tumor Targeting with Apatinib-loaded Nanoparticles and Sonodynamic Combined Therapy.

This study implies the enhancement of apatinib killing effect in 4T1 tumor cells through constructing drug-loaded nanoparticles apatinib/Ce6@ZIF- 8@Membranes (aCZM) to enhance tumor therapeutic targeting and reduce toxic side following sonodynamic therapy (SDT). apatinib/Ce6@ZIF-8 (aCZ) were synthesized by in situ encapsulation, and aCZM were constructed by encapsulating the nanoparticles with extracted breast cancer 4T1 cell membranes. aCZM were characterized and tested for the stability by electron microscopy, and the membrane proteins on the nanoparticles' surface were assessed using SDS-PAGE gel electrophoresis. The cell viability of 4T1 cells following treatment with aCZM was tested using cell counting kit-8 (CCK-8). The uptake of nanoparticles was detected by laser confocal microscopy and flow cytometry, and the SDT-mediated production of reactive oxygen species (ROS) was verified by singlet oxygen sensor green (SOSG), electron spin resonance (ESR), and DCFH-DA fluorescent probes. The CCK-8 assay and flow cytometry using Calcein/PI were used to assess the antitumoral effect of aCZM nanoparticles under SDT. The biosafety of aCZM was further verified in vitro and in vivo using the hemolysis assay, routine blood test and H&E staining of vital organs in Balb/c mice. aCZM with an average particle size of about 210.26 nm were successfully synthesized. The results of the SDS-PAGE gel electrophoresis experiment showed that aCZM have a band similar to that of pure cell membrane proteins. The CCK-8 assay demonstrated the absence of effects on cell viability at a low concentration range, and the relative cell survival rate reached more than 95%. Laser confocal microscopy and flow cytometry analysis showed that aCZM treated group has the strongest fluorescence and the highest cellular uptake of nanoparticles. SOSG, ESR, and DCFH-DA fluorescent probes all indicated that the aCZM + SDT treated group has the highest ROS production. The CCK-8 assay also showed that when the ultrasound intensity was fixed at 0.5 W/cm2, the relative cell survival rates in the medium concentration group (10 μg/ml) (5.54 ± 1.26%) and the high concentration group (20 μg/ml) (2.14 ± 1.63%) were significantly lower than those in the low concentration group (5 μg/ml) (53.40 ± 4.25%). Moreover, there was a concentration and intensity dependence associated with the cellkilling effect. The mortality rate of the aCZM in the ultrasound group (44.95 ± 3.03%) was significantly higher than that of the non-ultrasound (17.00 ± 2.26%) group and aCZ + SDT group (24.85 ± 3.08%) (P<0.0001). The live and dead cells' staining (Calcein/PI) also supported this result. Finally, in vitro hemolysis test at 4 and 24 hours showed that the hemolysis rate of the highest concentration group was less than 1%. The blood routine, biochemistry, and H&E staining results of major organs in Balb/c mice undergoing nano-treatments showed no obvious functional abnormalities and tissue damage in 30 days. In this study, a multifunctional bionic drug delivery nanoparticles (aCZM) system with good biosafety and compatibility in response to acoustic dynamics was successfully constructed and characterized. This system enhanced apatinib killing effect on tumor cells and reduced toxic side effects under SDT.

Effects of therapeutic ultrasound in patients with knee osteoarthritis: A systematic review and meta-analysis

BackgroundTherapeutic ultrasound (US) is a treatment for knee osteoarthritis (KOA), but its efficacy and safety are unclear. The objective of this study is to quantify the effect of US on pain relief and function recovery in KOA, and to analyze the US treatment duration and parameters on treatment outcome. MethodsWe searched PubMed, MEDLINE, EMBASE, Google Scholar, Cochrane databases and ClinicalTrials.gov databases up to April 7, 2023. RCTs that compared the efficacy of therapeutic US with the control in KOA were included in the study, and the methodological quality of the trials was assessed using the Cochrane Risk of Bias tool. ResultsTwenty-one RCTs (1315 patients) were included. US had a positive effect on visual analog scale (VAS) (SMD = −0.64, 95 % CI [-0.88, −0.40], I2 = 71 %) and Western Ontario and McMaster Universities (WOMAC) total scale (SMD = −0.45, 95 % CI [-0.69, −0.20]; I2 = 67 %). Pulsed US with an intensity ≤2.5 W/cm2 reduced visual analog scale (VAS), and differed in sessions (24 sessions (SMD = −0.80, 95 % CI [-1.07, −0.53], I2 = 0 %) vs 10 sessions (SMD = −0.71, 95 % CI [-1.09, −0.33], I2 = 68 %)). For pulsed US, a duration of treatment of 4–8 weeks (SMD = −0.69, 95 % CI [-1.13, −0.25], I2 = 73 %) appeared to be superior to ≤4 weeks (SMD = −0.77, 95 % CI [-1.04, −0.49], I2 = 0 %) for reducing visual analog scale (VAS). No US treatment-related adverse events were reported. ConclusionTherapeutic US may be a safe and effective treatment for patients with KOA. The mode, intensity, frequency, and duration of US may affect the effectiveness of pain relief. Pulsed US with an intensity ≤2.5 W/cm2, 24 sessions, and a treatment duration of ≤4 weeks appears to have better pain relief.

Ultrasound enhanced diffusion in hydrogels: An experimental and non-equilibrium molecular dynamics study.

Focused ultrasound has experimentally been found to enhance the diffusion of nanoparticles; our aim with this work is to study this effect closer using both experiments and non-equilibrium molecular dynamics. Measurements from single particle tracking of 40nm polystyrene nanoparticles in an agarose hydrogel with and without focused ultrasound are presented and compared with a previous experimental study using 100nm polystyrene nanoparticles. In both cases, we observed an increase in the mean square displacement during focused ultrasound treatment. We developed a coarse-grained non-equilibrium molecular dynamics model with an implicit solvent to investigate the increase in the mean square displacement and its frequency and amplitude dependencies. This model consists of polymer fibers and two sizes of nanoparticles, and the effect of the focused ultrasound was modeled as an external oscillating force field. A comparison between the simulation and experimental results shows similar mean square displacement trends, suggesting that the particle velocity is a significant contributor to the observed ultrasound-enhanced mean square displacement. The resulting diffusion coefficients from the model are compared to the diffusion equation for a two-time continuous time random walk. The model is found to have the same frequency dependency. At lower particle velocity amplitude values, the model has a quadratic relation with the particle velocity amplitude as described by the two-time continuous time random walk derived diffusion equation, but at higher amplitudes, the model deviates, and its diffusion coefficient reaches the non-hindered diffusion coefficient. This observation suggests that at higher ultrasound intensities in hydrogels, the non-hindered diffusion coefficient can be used.

Research of Acoustic Cavitation: Results, Practical Implementation and Development Prospects

The most significant results of research performed in the Belarusian State University University of Informatics and Radioelectronics, aimed at creating methods and instruments for monitoring cavitation and controlling its activity, are presented. To achieve this goal, it was necessary to clarify the mechanisms and patterns of new and little-studied phenomena: ultrasonic capillary effect, sonoluminescence, cavitation noise and its spectral components and evaluate the possibilities of their use for hardware implementation as cavitation indicators. New cavitation phenomena have been discovered: reverse ultrasonic capillary effect, generation of constant EMF under the influence of alternating pressure of ultrasonic frequency; acoustic clearing of the cavitation area with pulsed modulation of the ultrasonic field, the effect of long-term memory of the cavitation properties of the liquid. Previously unknown patterns have been established: it is shown that the cavitation region goes through four stages of development with increasing ultrasound intensity; a theorem on the maximum cavitation activity was formulated; the spectral characteristics of cavitation noise were established, correlating with the intensity of sonoluminescence. It has been shown that pulsed modulation of the ultrasonic field makes it possible to control the dynamics of the development of the cavitation region and the activity of cavitation. Based on the data obtained, new methods and instruments have been developed to study cavitation and control its activity. In a number of parameters, the created equipment surpasses the best world samples, what is confirmed by deliveries to the Russia, EU countries, China, USA and South Korea.

Muscle Ultrasound Echo Intensity and Fiber Type Composition in Young Females.

Ultrasonography has been extensively used to evaluate skeletal muscle morphology. The echo intensity, i.e., the mean pixel intensity of a specific region of interest in an ultrasound image, may vary among muscles and individuals with several intramuscular parameters presumed to influence it. The purpose of this study was to investigate the correlation between muscle echo intensity and muscle fiber type composition in humans. Thirteen female physical education students (age: 22.3 ± 5.4 years, height: 1.63 ± 0.06 m, body mass: 59.9 ± 7.4 kg) with no history of systematic athletic training participated in the study. Body composition with dual X-ray absorptiometry, leg-press maximum strength (1-RM), echo intensity, and the cross-sectional area (CSA) of the vastus lateralis (VL) muscle according to ultrasonography were measured. Muscle biopsies were harvested from the VL site where the echo intensity was measured. VL echo intensity was not significantly correlated with the percentage of type I muscle fibers or with the percentage area of type I muscle fibers. However, when VL echo intensity was corrected for the subcutaneous fat thickness at the site of the measurement, it was significantly correlated with the percentage of type I muscle fibers (r = 0.801, p < 0.01) and the percentage area of type I muscle fibers (r = 0.852, p < 0.01). These results suggest that the echo intensity of the vastus lateralis muscle corrected for the subcutaneous fat thickness at the measurement site may provide an estimate of the muscle fiber type composition, at least in young moderately trained females.

Echo-intensity characterization at implant sites and novel diagnostic ultrasonographic markers for peri-implantitis.

To apply high-frequency ultrasound (HFUS) echo intensity for characterizing peri-implant tissues at healthy and diseased sites and to investigate the possible ultrasonographic markers of health versus disease. Sixty patients presenting 60 implants diagnosed as healthy (N = 30) and peri-implantitis (N = 30) were assessed with HFUS. HFUS scans were imported into a software where first-order greyscale outcomes [i.e., mean echo intensity (EI)] and second-order greyscale outcomes were assessed. Other ultrasonographic outcomes of interest involved the vertical extension of the hypoechoic supracrestal area (HSA), soft-tissue area (STA) and buccal bone dehiscence (BBD), among others. HFUS EI mean values obtained from peri-implant soft tissue at healthy and diseased sites were 122.9 ± 19.7 and 107.9 ± 24.7 grey levels (GL); p = .02, respectively. All the diseased sites showed the appearance of an HSA that was not present in healthy implants (area under the curve = 1). The proportion of HSA/STA was 37.9% ± 14.8%. Regression analysis showed that EI of the peri-implant soft tissue was significantly different between healthy and peri-implantitis sites (odds ratio 0.97 [95% confidence interval: 0.94-0.99], p = .019). HFUS EI characterization of peri-implant tissues shows a significant difference between healthy and diseased sites. HFUS EI and the presence/absence of an HSA may be valid diagnostic ultrasonographic markers to discriminate peri-implant health status.

β-crosslaps in knee osteoarthritis – assessment and rehabilitation

Abstract: The bone turnover is important for the progression of osteoarthritis. The C-terminal telopeptide of type I collagen, β-CrossLaps (β-CTx) is considered as the first-choice bone resorption markers. Today, the biochemical markers have been associated with pain and disease severity in knee osteoarthritis (KOA) patients. We studied the association between β-CTx and functional status in KOA patients, pre- and postrehabilitation program. The primary goals of our study are both to establish the correlation between the serum level of β-CTx and other parameters of clinical and functional status in KOA patients and to compare the CTX-I values before and after rehabilitation program. We respected the actual international management recommendations for KOA. A total of 130 patients were randomly allocated into two distinct groups: Study Group (SG = 90 patients) performed 10 sessions of complete rehabilitation program (magnetodiaflux, transcutaneous nerve stimulation, ultrasound and low intensity laser treatment, kinetic measures), and Control Group (CG = 40 patients) performed 10 sessions of kinetic program. Both programs were performed daily, 5 days/week, 2 weeks. Evaluation of patients was carried out in two stages - initial (T1) and after 3 months (T2). Comparing the initial values with the final ones for β-CTx, we noticed a high significant difference between initial and final values only in SG patients. For the both T1 and T2 moments, there was no a statistically significant difference between β-CTx values from the two groups. Analyzing the differences between the values of clinical parameters (Six Minutes Walking Test, Timed Up-and-Go test, walk cadence and Symmetry index in walk) obtained between the patients from the two groups, we noticed that, for the T2 moment, there was a statistically significant difference between studied parameters, except walk cadence. In the assessment of global KOA patient status (clinical and functional status in accordance with bone-cartilage interface dynamics), β-CTx has significant value and could be used for monitoring the individualized rehabilitation program.

Experimental and Computational Analysis of High-Intensity Focused Ultrasound Thermal Ablation in Breast Cancer Cells: Monolayers vs. Spheroids.

High-intensity focused ultrasound (HIFU) is a non-invasive therapeutic modality that uses precise acoustic energy to ablate cancerous tissues through coagulative necrosis. In this context, we investigate the efficacy of HIFU ablation in two distinct cellular configurations, namely 2D monolayers and 3D spheroids of epithelial breast cancer cell lines (MDA-MB 231 and MCF7). The primary objective is to compare the response of these two in vitro models to HIFU while measuring their ablation percentages and temperature elevation levels. HIFU was systematically applied to the cell cultures, varying ultrasound intensity and duty cycle during different sonication sessions. The results indicate that the degree of ablation is highly influenced by the duty cycle, with higher duty cycles resulting in greater ablation percentages, while sonication duration has a minimal impact. Numerical simulations validate experimental observations, highlighting a significant disparity in the response of 2D monolayers and 3D spheroids to HIFU treatment. Specifically, tumor spheroids require lower temperature elevations for effective ablation, and their ablation percentage significantly increases with elevated duty cycles. This study contributes to a comprehensive understanding of acoustic energy conversion within the biological system during HIFU treatment for 2D versus 3D ablation targets, holding potential implications for refining and personalizing breast cancer therapeutic strategies.

Multiphysics analysis of a high-intensity ultrasound system applied to a three-layer animal tissue

High-intensity ultrasound systems for medical therapy must be carefully designed, implemented, and applied to avoid tissue damage or injury considering stimulation and relaxation time, frequency, and intensity of ultrasound. Based on these concerns and considering a test three-layer animal tissue consisting of skin, muscle, and bone, we determined the frequency and intensity at which ultrasound effectively stimulates the test animal tissues. In addition, from these ultrasound frequencies and intensities, and taking care the critical temperature recommended to preserve the integrity of the human tissue and avoid any tissue injury, we determine the stimulation and relaxation times. For this purpose, we performed a multiphysics simulation that describes the spatial and temporal dynamics of the thermoacoustic effect of ultrasound applied to test animal tissues. To practically demonstrate this ultrasound behavior, we perform an experimental setup based on an electronic HITU device designed and implemented to freely adjust the ultrasound intensity and frequency, as well as the stimulation time of the test animal tissues. Finally, we conclude that, depending on the test tissue, an ultrasound therapy system should allow the selection of the intensity and frequency of applied ultrasound, as well as the stimulation time to avoid tissue injury, which can be considered by health ministries around the world.

Quadriceps composition and function influence downhill gait biomechanics >1 year following anterior cruciate ligament reconstruction

BackgroundQuadriceps dysfunction is common following anterior cruciate ligament reconstruction and contributes to aberrant gait biomechanics. Changes in quadriceps composition also occur in these patients including greater concentrations of non-contractile tissue. The purpose of this study was to evaluate associations between quadriceps composition, function, and gait biomechanics in individuals with anterior cruciate ligament reconstruction. MethodsForty-eight volunteers with anterior cruciate ligament reconstruction completed gait biomechanics and quadriceps function and composition assessments. Gait biomechanics were sampled during downhill walking (−10° slope) on an instrumented treadmill. Quadriceps function (peak torque and rate of torque development) was assessed via maximal isometric contractions, while composition was evaluated via ultrasound echo intensity. FindingsGreater quadriceps peak torque was associated with a greater peak knee extension moment (r = 0.365, p = 0.015). Greater vastus lateralis echo intensity (i.e. poorer muscle quality) was associated with less knee flexion displacement (r = −0.316, p = 0.032). Greater echo intensity of the vastus lateralis (r = −0.298, p = 0.044) and rectus femoris (r = −0.322, p = 0.029) was associated with a more abducted knee angle at heel strike. Quadriceps peak torque explained 11–16% of the variance in echo intensity. InterpretationBoth quadriceps function and composition influence aberrant gait biomechanics following anterior cruciate ligament reconstruction. Quadriceps composition appears to provide insight into quadriceps dysfunction independent of muscle strength, as they associated with different gait biomechanics outcomes and shared minimal variance. Future research is necessary to determine the influence of changes in quadriceps composition on joint health outcomes.

The impact of ultrasound treatment on glycolytic enzymes when applied to crude extracts from early post-mortem bovine muscle

The rate of pH decline post – mortem and its interaction with temperature influences the final tenderness of meat, and therefore, the manipulation of the rate of pH decline is a strategy of interest in order to obtain consistent high quality meat. Ultrasound is a potential early post - mortem carcass intervention, which may alter the rate of glycolysis based on its ability to alter enzyme activity. In this study, homogenates (prepared from early post-mortem Longissimus thoracis et lumborum muscle) were subjected to different ultrasound intensities (0 %/60 %/100 % amp) and treatment durations (15/ 30 min). The effect of these treatments on the inherent activity of the glycolytic enzymes was investigated using an in vitro glycolytic buffer model system. It was found that ultrasound treatment intensity and duration had a significant interactive effect on the rate of pH decline, and on reducing sugars and lactic acid concentrations, specifically following the 100 % amp ultrasound for 30 min treatment and between 30 and 240 min incubation. No significant differences in pH or metabolites content were observed between treatments after 1440 min of incubation. No effect of ultrasound intensity or treatment duration was observed on the degradation of glycogen. Under the reported conditions of this trial, it can be concluded that the application of ultrasound has limited potential to have an impact on the glycolytic pathways in bovine muscle.

A spatiotemporal deconvolution approach for measurements of therapeutic ultrasound pressures, intensities, and beamwidths

Complete characterization of high intensity focused ultrasound (HIFU) systems includes measurements of transmitted pressure at the focal plane with a hydrophone. However, highly focused, nonlinear HIFU beams can result in considerable spatial averaging artifacts due to finite area of the hydrophone active element. Spatiotemporal deconvolution (STD) can correct for hydrophone spatial averaging (Wear, IEEE Trans. UFFC 69, 1243–1256 (2021)]. The objective of the present work is to extend validation of STD from diagnostic levels (6 MPa) to therapeutic levels (49 MPa). Three HIFU transducers (1.45 MHz F/1, 1.53 MHz F/1.5, and 3.91 MHz F/1) were driven in tone bursts (Agilent HP3314A function generator, ENI 240L amplifier) to generate HIFU fields in a degassed, deionized water tank with focal compressional pressures of 49, 16, and 29 MPa. Fields were measured in focal planes with two hydrophones (Onda HFO 100-μm fiber-optic; Onda HNA-0400 400-μm robust needle). STD reduced inter-hydrophone differences from −18 ± 11% to 0 ± 8% (peak compressional pressure), −8 ± 4% to −5 ± 5% (peak rarefactional pressure), −20% ± 7% to −3 ± 8% (pulse intensity integral), and 21 ± 12% to −2 ± 3% (beam FWHM). STD reduces dependence of measurements on hydrophone active element size. STD reduces reliance on fiber optic hydrophones, which can be expensive, difficult to use, and prone to radiation-force-induced sensor misalignment.

Green Extraction of Oleoresin from Pink Pepper Fruits: Effect of Experimental Conditions and Characterization

This work evaluated the green extraction of oleoresin from pink pepper fruits (ORPPF) using ultrasound-assisted extraction (UAE) and ethanol as a solvent. The effects of temperature, ultrasound power intensity, sample to solvent ratio and time on the global extraction yield (YGE) and phenolic compounds yield (YPC) were evaluated. The oleoresin samples were characterized and its antimicrobial activity determined, and the obtained results were compared to conventional extraction in Soxhlet. From the results it was found that the application of the highest levels of the independent variables favored the extraction process. The maximum values of YGE and YPC were 28.60 wt% and 6.37 mg GAE per g fruit, respectively, obtained at 60 °C, 100% of ultrasound power (165 W), 1:20 g mL−1 (sample:solvent) and 45 min. Under maximized conditions, the ORPPF obtained by UAE showed a content of phenolic compounds and antioxidant activity inferior to soxhlet–ethanol extraction. However, the time and solvent consumption were reduced. Oleic and linoleic acids predominated in the fatty acid composition of ORPPF, in addition to sesquiterpenes and gallic and syringic acids. The ORPPF presented weak antibacterial activity, with minimum inhibitory concentration ranging from 31.25 to 125 mg mL−1.

Enhancing the Gelation Behavior of Transglutaminase-Induced Soy Protein Isolate(SPI) through Ultrasound-Assisted Extraction.

Gelation, as an important functional property of soy protein isolate (SPI), can be improved by some green technologies in food manufacturing, including ultrasound, ultrahigh pressure and microwave treatments. This work investigated the effect of an alkaline solubilisation step in SPI extraction combined with sonication on protein properties. The TGase-induced gel of the modified SPI was prepared to explore the effect of ultrasound on gel properties, including structures, strength, water-holding capacity and rheological properties. Additionally, the differences between traditional ultrasound modification of SPI and current modification methods were analyzed. The results showed that the ultrasonication-assisted extraction method could result in a significant increase in extraction rate from 24.68% to 42.25%. Moreover, ultrasound-assisted modification of SPI gels induced with transglutaminase (TGase) exhibited significant improvement in mechanical properties, such as texture, water-holding capacity and rheological properties, In particular, SPI extracted at 400 W ultrasound intensity for 180 s showed the best overall performance in terms of gel properties. Our method efficiently uniformizes gel structure, enhancing mechanical properties compared to conventional ultrasound methods, which reduced energy consumption and costs. These findings provide insights into the production of high-gelation SPI in food manufacturing.

High-resolution acoustic mapping of tunable gelatin-based phantoms for ultrasound tissue characterization.

Background: The choice of gelatin as the phantom material is underpinned by several key advantages it offers over other materials in the context of ultrasonic applications. Gelatin exhibits spatial and temporal uniformity, which is essential in creating reliable tissue-mimicking phantoms. Its stability ensures that the phantom's properties remain consistent over time, while its flexibility allows for customization to match the acoustic characteristics of specific tissues, in addition to its low levels of ultrasound scattering. These attributes collectively make gelatin a preferred choice for fabricating phantoms in ultrasound-related research. Methods: We developed gelatin-based phantoms with adjustable parameters and conducted high-resolution measurements of ultrasound wave attenuation when interacting with the gelatin phantoms. We utilized a motorized acoustic system designed for 3D acoustic mapping. Mechanical evaluation of phantom elasticity was performed using unconfined compression tests. We particularly examined how varying gelatin concentration influenced ultrasound maximal intensity and subsequent acoustic attenuation across the acoustic profile. To validate our findings, we conducted computational simulations to compare our data with predicted acoustic outcomes. Results: Our results demonstrated high-resolution mapping of ultrasound waves in both gelatin-based phantoms and plain fluid environments. Following an increase in the gelatin concentration, the maximum intensity dropped by 30% and 48% with the 5MHz and 1MHz frequencies respectively, while the attenuation coefficient increased, with 67% more attenuation at the 1MHz frequency recorded at the highest concentration. The size of the focal areas increased systematically as a function of increasing applied voltage and duty cycle yet decreased as a function of increased ultrasonic frequency. Simulation results verified the experimental results with less than 10% deviation. Conclusion: We developed gelatin-based ultrasound phantoms as a reliable and reproducible tool for examining the acoustic and mechanical attenuations taking place as a function of increased tissue elasticity and stiffness. Our experimental measurements and simulations gave insight into the potential use of such phantoms for mimicking soft tissue properties.

Saline extraction assisted by ultrasound: a method to obtain purified phycocyanin

The influence of ultrasound intensity and saline solution concentration (NH4Cl and CaCl2) on phycocyanin extraction from Arthrospira platensis was evaluated. The intensity had a significant effect on phycocyanin content and purity, while the saline solution concentration only had an effect on purity. The optimum extraction condition was obtained at 41% of intensity and 8.5 g.L−1 of CaCl2 solution. In this condition, ultrasound promoted cell disruption efficiently, increasing the extraction yield. The combination of ultrasound with CaCl2 solution reduced the co-extraction of chlorophylls and other proteins, providing more purified extracts. The freezing and thawing method was compared to the best condition obtained, and it showed no significant difference for phycocyanin content but better results for purity. Overall, ultrasound treatment may be considered a promising technology to obtain phycocyanin by the food industry without additional purification techniques due to the reduced extraction time, less use of energy, and easy scale-up.

Continuous Low-Intensity Ultrasound Improves Cartilage Repair in Rabbit Model of Subchondral Injury.

Subchondral drilling (SD), a bone marrow stimulation technique, is used to repair cartilage lesions that lack regenerative potential. Cartilage repair outcomes upon SD are typically fibrocartilaginous in nature with inferior functionality. The lack of cues to foster the chondrogenic differentiation of egressed mesenchymal stromal cells upon SD can be attributed for the poor outcomes. Continuous low-intensity ultrasound (cLIUS) at 3.8 MHz is proposed as a treatment modality for improving cartilage repair outcomes upon marrow stimulation. Bilateral defects were created by SD on the femoral medial condyle of female New Zealand white rabbits (n = 12), and the left joint received cLIUS treatment (3.8 MHz, 3.5 Vpp, 8 min/application/day) and the contralateral right joint served as the control. On day 7 postsurgery, synovial fluid was aspirated, and the cytokine levels were assessed by Quantibody™ assay. Rabbits were euthanized at 8 weeks and outcomes were assessed macroscopically and histologically. Defect areas in the right joints exhibited boundaries, incomplete fill, irregular cartilage surfaces, loss of glycosaminoglycan (GAG), and absence of chondrocytes. In contrast, the repaired defect area in the joints that received cLIUS showed complete fill, positive staining for GAG with rounded chondrocyte morphology, COL2A1 staining, and columnar organization. Synovial fluid collected from cLIUS-treated left knee joints had lower levels of IL1, TNFα, and IFNγ when compared to untreated right knee joints, alluding to the potential of cLIUS to mitigate early inflammation. Further at 8 weeks, left knee joints (n = 12) consistently scored higher on the O'Driscoll scale, with a higher percent hyaline cartilage score. No adverse impact on bone or change in the joint space was noted. Upon a single exposure of cLIUS to TNFα-treated cells, nuclear localization of pNFκB and SOX9 was visualized by double immunofluorescence and the expression of markers associated with the NFκB pathway was assayed by quantitative real-time polymerase chain reaction. cLIUS extends its chondroprotective effects by titrating pNFκB levels, preventing its nuclear translocation, while maintaining the expression of SOX9, the collagen II transcription factor. Our combined results demonstrate that healing of chondral defects treated with marrow stimulation by SD can be accelerated by employing cLIUS regimen that possesses chondroinductive and chondroprotective properties. Impact statement Repair of cartilage represents an unsolved biomedical burden. In vitro, continuous low-intensity ultrasound (cLIUS) has been demonstrated to possess chondroinductive and chondroprotective potential. To our best knowledge, the use of cLIUS to improve cartilage repair outcomes upon marrow stimulation, in vivo, has not been reported and our work reported here fills that gap. Our results demonstrated enhanced cartilage repair outcomes under cLIUS (3.8 MHz) in a rabbit model of subchondral injury by subchondral drilling. Enhanced repair stemmed from mesenchymal stem cell differentiation in vivo and the subsequent synthesis of articular cartilage-specific matrix.