Duration Of Ultrasound Exposure Research Articles

Quantitative evaluation of anti-biofilm cavitation activity seeded from microbubbles or protein cavitation nuclei by passive acoustic mapping

Bacterial biofilms represent a major challenge for effective antibiotic therapy as they confer physical and functional changes that protect bacteria from their surrounding environment. In this work, focused ultrasound in combination with cavitation nuclei was used to disrupt biofilms of Staphylococcus aureus and Pseudomonas aeruginosa, both of which are on the World Health Organization's priority list for new antimicrobial research. 
Approach: Single species biofilms were exposed to ultrasound (0.5 MHz centre frequency, 0.5-1.5 MPa peak rarefactional pressure, 200 cycle pulses, 5 Hz repetition frequency, 30 s duration), in the presence of two different types of cavitation nuclei. Quantitative passive acoustic mapping (PAM) was used to monitor cavitation emissions during treatment using a calibrated linear array. 
Main Results: It was observed that the cumulative energy of acoustic emissions during treatment was positively correlated with biofilm disruption, with differences between bacterial species attributed to differences in biofilm morphology. PCaN provided increased biofilm reduction compared to microbubbles due in large part to their persistence over the duration of ultrasound exposure. There was also good correlation between the spatial distribution of cavitation as characterized by PAM and the extent of biofilm disruption observed with microscopy. 
Significance: Collectively, the results from this work indicate the potential broad applicability of cavitation for eliminating biofilms of priority pathogens and the opportunity presented by Passive Acoustic Mapping for real-time monitoring of antimicrobial processes.

Effect of ultrasound on mass transfer during vacuum impregnation and selected quality parameters of products: A case study of carrots

Many unit operations in the food industry are diffusional driven. These processes are usually very slow and difficult to handle for specific groups of raw materials. Vacuum impregnation (VI) is one example. Impregnating low-porous or densely-structured materials is problematic and often requires low pressure, which can negatively affect product quality and be expensive in energy consumption. This research aimed to evaluate ultrasound (US) as a factor in intensifying mass transfer and enhancing its effectiveness in the VI process. Experiments on impregnation enhanced with ultrasound applied at different stages of the process were carried out. Carrot, a difficult-to-process raw material, was impregnated with ascorbic acid as a mass transfer marker. The process’s effectiveness and selected quality parameters were then analyzed. Ultrasound was found to have a positive influence on mass transfer during VI. The effects of ultrasound enhancement were different for particular processes, and depended on the stage of the application and duration of US exposure. The greatest increase in the tissue’s ascorbic acid content (60% compared to the non-ultrasound-assisted process) was observed when ultrasound was applied continuously throughout the process. Applying ultrasound only during the relaxation (at atmospheric pressure) or aeration periods resulted in a similar effect – c.a. 20% increase in the marker’s content. The smallest increase (10%) was observed when ultrasound was applied only during the vacuum period. Applying US did not result in any unfavorable color change. In most cases, pH decreased, which is favorable for the semi-product’s stability. The carotenoid and phenolic compounds’ content did not decrease. The results unequivocally indicate that ultrasound has great potential for use as a mass transfer accelerator in the VI process for low porosity materials. The effectiveness of the US is influenced not only by pressure but also by exposure duration. The synergistic effect observed using ultrasound-enhanced impregnation throughout the process confirmed this hypothesis.

Oxidative homeostasis in germinating pea seeds (isum sativum) depending on ultrasonic exposure duration

The effects of ultrasonic exposure durations (5, 10 and 20 min) with intensity of 25 kW/m2 and the frequency of 26.1 kHz on the extent of lipid peroxidation, oxidative modification of proteins, the activity of cysteine proteinases, and gene expression in germinating pea seeds were studied. It has been shown that the intensity in the area that had seeds planted (just over the central ultrasound generator) was rather uniformly distributed, but at the same time gave rise to diffuse reflection. A range of tendencies in changes of the indicators under study were seen after ultrasound exposure. The level of malonic dialdehyde increased with increasing duration of ultrasound exposure. This study revealed the increased amount of oxidized proteins in germinating pea seeds after a 10 min-exposure to ultrasound, and a decrease in the level of oxidative modification of proteins present in seeds subjected to ultrasound for a period of 20 min. The activity of cysteine proteinases was higher in pea seeds after a 5-min exposure to ultrasound, but the amount of mRNA transcripts increased in all experimental samples.

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.

Extending the Shelf Life of Fresh Khalal Barhi Dates via an Optimized Postharvest Ultrasonic Treatment.

The Barhi date is a high-quality date cultivar whose fruits (dates) are plucked and eaten fresh when they reach the Khalal maturity stage due to their sweetness, crispiness, and yellow skin color. After harvesting, Khalal Barhi fruits rapidly matured to the Rutab stage, where their tissues become soft and their skin color browner. This results in a decrease in their market value and customer demand. This study aims at investigating the effectiveness of the postharvest ultrasonic treatment in conserving the physical, microbial, and nutritional quality of Barhi fruits and extending their shelf life. To achieve the goals of the present work, the response surface methodology (RSM) was used for the optimization of the ultrasonic intensity (50, 100, 150, and 200 W/cm2) and application time (5, 10, 15, and 20 min) to preserve the Barhi dates high quality features for varied storage temperatures (1, 5, 15, and 25 °C) and duration (1, 6, 16, and 21 days). In RSM, a four-factors-mixed-levels central composite rotatable design (CCRD) was applied to optimize the ultrasound treatment and storage environments for better-quality physical [total soluble solids (TSS), firmness, and total color changes (ΔE)], microbial [total viable count (TVC)], nutritional [total phenolic content (TPC), DPPH antiradical activity, glucose, and fructose] features of Barhi dates. The outcomes showed that ultrasound intensity and its application time, storage temperature, and storage period influence the physical, microbial, and nutritional quality attributes in different magnitudes. The ideal settings for lessening the changes in the physical attributes, eliminating the microbial growth, and improving the nutritional quality attributes were 140 W/cm2, 5.2 min, 20.9 °C, and 21 days for ultrasound intensity, ultrasound exposure duration, storage temperature, and storage duration, respectively. In conclusion, this study proved the potential application of ultrasound for persevering the excellence aspects of Barhi dates and identified the ideal ultrasound environments for maintaining the physical, microbial, and nutritional quality features of Barhi dates during extended storing.

Effects of intermittent duration of ultrasound exposure on temperature rise and behavior of cavitation bubbles in bubble-enhanced ultrasonic heating

Effects of intermittent duration of ultrasound exposure on temperature rise and behavior of cavitation bubbles in bubble-enhanced ultrasonic heating

How to Interpret the Ultrasound Output Display Standard for Diagnostic Ultrasound Devices: Version 3.

How to Interpret the Ultrasound Output Display Standard for Diagnostic Ultrasound Devices: Version 3.

2P5-15 Effect of Intermittent Duration of Ultrasound Exposure on Bubble Behavior and Temperature Rise in Bubble-Enhanced Ultrasonic Heating

2P5-15 Effect of Intermittent Duration of Ultrasound Exposure on Bubble Behavior and Temperature Rise in Bubble-Enhanced Ultrasonic Heating

Влияние длительности ультразвукового воздействия на состояние микроциркуляторного русла и системы гемостаза у крыс

Влияние длительности ультразвукового воздействия на состояние микроциркуляторного русла и системы гемостаза у крыс

Association of Prenatal Ultrasonography and Autism Spectrum Disorder

The prevalence of autism spectrum disorder (ASD) has been increasing rapidly, with current estimates of 1 in 68 children affected. Simultaneously, use of prenatal ultrasonography has increased substantially, with limited investigation into its safety and effects on brain development. Animal studies have demonstrated that prenatal ultrasonography can adversely affect neuronal migration. To quantify prenatal ultrasound exposure by the frequency, timing, duration, and strength of ultrasonographic scans in children with later ASD, developmental delay, and typical development. This case-control study included 107 patients with ASD, 104 control individuals with developmental delay, and 209 controls with typical development. Participants were identified from medical records based on prenatal care and delivery at Boston Medical Center, a diverse, academic, safety-net medical center, from July 1, 2006, through December 31, 2014, with a gestational age at birth of at least 37 weeks. Data were analyzed from May 1, 2015, through November 30, 2017. Ultrasonographic exposure was quantified by the number and timing of scans, duration of exposure, mean strength (depth, frame rate, mechanical index, and thermal index), and time of Doppler and 3- and 4-dimensional imaging. Among participants with ASD and controls with developmental delay and typical development, ultrasound exposure was quantified and compared per trimester and for the entire pregnancy, with adjustment for infant sex, gestational age at birth, and maternal age. A total of 420 participants were included in the study (328 boys [78.1%] and 92 girls [21.9%]; mean age as of January 1, 2016, 6.6 years; 95% CI, 6.5-6.8 years). The ASD group received a mean of 5.9 scans (95% CI, 5.2-6.6), which was not significantly different from the 6.1 scans (95% CI, 5.4-6.8) in the developmental delay group or the 6.3 scans (95% CI, 5.8-6.8) in the typical development group. Compared with the typical development group, the ASD group had shorter duration of ultrasound exposure during the first (290.4 seconds [95% CI, 212.8-368.0 seconds] vs 406.4 seconds [95% CI, 349.5-463.3 seconds]) and second (1687.6 seconds [95% CI, 1493.8-1881.4 seconds] vs 2011.0 seconds [95% CI, 1868.9-2153.1 seconds]) trimesters but no difference in the number of scans. The ASD group had greater mean depth of ultrasonographic penetration than the developmental delay group in the first trimester (12.5 cm [95% CI, 12.0-13.0 cm] vs 11.6 cm [95% CI, 11.1-12.1 cm]). The ASD group had greater mean depth than the typical development group during the first (12.5 cm [95% CI, 12.0-13.0 cm] vs 11.6 cm [95% CI, 11.3-12.0 cm]) and the second (12.9 cm [95% CI, 12.6-13.3 cm] vs 12.5 cm [95% CI, 12.2-12.7 cm]) trimesters. This study found significantly greater mean depth of ultrasonographic penetration in the ASD group compared with the developmental delay group in the first trimester and compared with the typical development group in the first and second trimesters. Further research is needed to determine whether other variables of ultrasound exposure also have adverse effects on the developing fetus.

EFFECTS OF ULTRASOUND ON ARTEMIA CYST INCUBATION

The present work aims to test the bioeffects of ultrasounds on cyst formation in the crustacean Artemia salina. It is designed to identify which durations of ultrasonic exposure are capable of influencing hatching rates. The transducers used in the experiment were operated at resonant (0.23[Formula: see text]MHz and 4.7[Formula: see text]MHz) and non-resonant (0.5[Formula: see text]MHz and 1[Formula: see text]MHz) frequencies and the intensities of 3.25[Formula: see text]mW/cm2 and 13.63[Formula: see text]mW/cm2. The Rayleigh–Plesset theoretical framework was used to calculate the dynamics of shell-encapsulated cysts. The duration of ultrasound exposure was approximately 2[Formula: see text]min every 2[Formula: see text]h, repeated 6 times in the culture range of 1–15[Formula: see text]h. The results demonstrate that irradiation at an intensity of 13.63[Formula: see text]mW/cm2 and a driving frequency of 0.23[Formula: see text]MHz increased the number of hatched larvae by approximately 31.7%, compared with unexposed control samples. In conclusion, the theoretical model provided a useful means of predicting the most efficient frequency of sonication.

Determination of Soft Tissue Breakpoint Based on Its Temperature Enhancement Pattern: In Vivo and In Vitro Experiments.

The breakpoint of fresh commercial meats and in vivo mice has been assessed using tissue temperature enhancement pattern. A 1cm length and 0.1cm diameter gold rod was implanted in fresh chicken breast, beef, fish, and in vivo Mus musculus white mice and was insonated with ultrasound. The temperature enhancement of gold rods was measured with a needle type thermistor over a temperature range from 35 to 50°C. From these results the breakpoints were determined by plotting the gold rod temperature versus ultrasound exposure duration using the interception point of two curves fitted by a linear regression equations of thermal response above and below 43°C. The linear correlation coefficients for all fitted curves lie within 0.985 and 0.997. The breakpoints were found to be 42.1±1.1, 42.3±0.9, 42.6±0.8 and 43.5±0.6 for fish, chicken breast, beef and in vivo Mus musculus white mice, respectively. The interception of the thermal response curves above and below 43°C. Soft tissue temperature enhancement pattern has demonstrated to be a fast method to determine breakpoint. It denotes the temperature where cells may start to be destroyed and may be used to spot the startup point in dosimetry of hyperthermia cancer therapy.

Patterning Expression of Regenerative Growth Factors Using High Intensity Focused Ultrasound

Temporal and spatial control of growth factor gradients is critical for tissue patterning and differentiation. Reinitiation of this developmental program is also required for regeneration of tissues during wound healing and tissue regeneration. Devising methods for reconstituting growth factor gradients remains a central challenge in regenerative medicine. In the current study we develop a novel gene therapy approach for temporal and spatial control of two important growth factors in bone regeneration, vascular endothelial growth factor, and bone morphogenetic protein 2, which involves application of high intensity focused ultrasound to cells engineered with a heat-activated- and ligand-inducible gene switch. Induction of transgene expression was tightly localized within cell-scaffold constructs to subvolumes of ∼30 mm³, and the amplitude and projected area of transgene expression was tuned by the intensity and duration of ultrasound exposure. Conditions for ultrasound-activated transgene expression resulted in minimal cytotoxicity and scaffold damage. Localized regions of growth factor expression also established gradients in signaling activity, suggesting that patterns of growth factor expression generated by this method will have utility in basic and applied studies on tissue development and regeneration.

Apoptosis of THP-1 macrophages induced by protoporphyrin IX-mediated sonodynamic therapy

BackgroundSonodynamic therapy (SDT) was developed as a localized ultrasound-activated cytotoxic therapy for cancer. The ability of SDT to destroy target tissues selectively is especially appealing for atherosclerotic plaque, in which selective accumulation of the sonosensitizer, protoporphyrin IX (PpIX), had been demonstrated. Here we investigate the effects of PpIX-mediated SDT on macrophages, which are the main culprit in progression of atherosclerosis.Methods and resultsCultured THP-1 derived macrophages were incubated with PpIX. Fluorescence microscopy showed that the intracellular PpIX concentration increased with the concentration of PpIX in the incubation medium. MTT assay demonstrated that SDT with PpIX significantly decreased cell viability, and this effect increased with duration of ultrasound exposure and PpIX concentration. PpIX-mediated SDT induced both apoptosis and necrosis, and the maximum apoptosis to necrosis ratio was obtained after SDT with 20 μg/mL PpIX and five minutes of sonication. Production of intracellular singlet oxygen and secondary disruption of the cytoskeleton were also observed after SDT with PpIX.ConclusionPpIX-mediated SDT had apoptotic effects on THP-1 macrophages via generation of intracellular singlet oxygen and disruption of the cytoskeleton. PpIX-mediated SDT may be a potential treatment to attenuate progression of atherosclerotic plaque.

Adjustment of Ultrasound Exposure Duration to Microbubble Sonodestruction Kinetics for Optimal Cell Sonoporation In Vitro

Cell sonoporation enables the delivery of various exogenous molecules into the cells. To maximize the percentage of reversibly sonoporated cells and to increase cell viability we propose a model for implicit dosimetry for adjustment of ultrasound (US) exposure duration. The Chinese hamster ovary cell suspension was supplemented with microbubbles (MB) and exposed to US, operating at the frequency of 880kHz, with a 100% duty cycle and with an output peak negative pressure (PNP) of 500kPa for durations ranging from 0.5 to 30s. Using diagnostic B-scan imaging we showed that the majority of the MB at 500kPa US peak negative pressure undergo sonodestruction in less than a second. During this time maximal number of reversibly sonoporated cells was achieved. Increase of US exposure duration did not increase sonoporated cell number, however it induced additional cell viability decrease. Therefore aiming to achieve the highest level of reversibly sonoporated cells and also to preserve the highest level of cell viability, the duration of US exposure should not exceed the duration needed for complete MB sonodestruction.

Sonolysis of Escherichia coli and Pichia pastoris in microfluidics

We report on an efficient ultrasound based technique for lysing Escherichia coli and Pichia pastoris with oscillating cavitation bubbles in an integrated microfluidic system. The system consists of a meandering microfluidic channel and four piezoelectric transducers mounted on a glass substrate, with the ultrasound exposure and gas pressure regulated by an automatic control system. Controlled lysis of bacterial and yeast cells expressing green fluorescence protein (GFP) is studied with high-speed photography and fluorescence microscopy, and quantified with real-time polymerase chain reaction (qRT-PCR) and fluorescence intensity. The effectiveness of cell lysis correlates with the duration of ultrasound exposure. Complete lysis can be achieved within one second of ultrasound exposure with a temperature increase of less than 3.3 °C. The rod-shaped E. coli bacteria are disrupted into small fragments in less than 0.4 seconds, while the more robust elliptical P. pastoris yeast cells require around 1.0 second for complete lysis. Fluorescence intensity measurements and qRT-PCR analysis show that functionality of GFP and genomic DNA for downstream analytical assays is maintained.

Increased uptake of nanoparticles in dividing cells mediated by sonoporation

This study examined ultrasound effects on cellular uptake of nanoparticles. The objectives were: (1) to measure the uptake of nanoparticles into cells after ultrasound exposure and (2) to determine the optimal duration of ultrasound exposure.

Vessel phantom fabrication using rapid prototyping technique for investigating thermal dosage profile in HIFU surgery

PurposeThe purpose of this paper is to propose a method for fabricating tumor vessel phantom and then investigate the thermal dosage profile caused by high‐intensity‐focused ultrasound (HIFU) surgery.Design/methodology/approachIn this paper, a thermal sensitive powder has been added to silicon‐based gel as a vessel phantom raw material for displaying the thermal dosage profile caused by HIFU. A fused deposition modeling system was used for fabricating the shell casting mold and the vessel arbor mold. The arbor prototype, made of wax, was solidified in the cavity of vessel arbor mold. The vessel phantom object embedded with the arbor prototype was created in the shell mold casting process. The vessel phantom was obtained by immersing the vessel phantom object into hot water (65°C) for melting the vessel arbor prototype. A HIFU experiment has been conducted for verifying the feasibility of displaying the thermal dosage profile of the fabricated vessel phantom. The HIFU experimental parameters including the driving power of HIFU transducer, ultrasound exposure duration and volume flow rate were used for investigating the thermal dosage variation by the perfusion of vessel phantom.FindingsThe properties of fabricated mimicking phantom agree well with those of human tissue. The experimental results show that the proposed method can fabricate the Y‐type vessel phantom. The proposed method has been proved as a promising fabrication process in fabricating the vessel phantom and it displays the thermal dosage profile in HIFU experiment.Originality/valueThe proposed method and the developed experimental apparatus are helpful for pre‐clinical HIFU surgery.

Mechanisms underlying the limited injectability of hydraulic calcium phosphate paste. Part ІІ: Particle separation study

Calcium phosphate cements (CPCs) are of great interest for bone augmentation procedures. In these a hydraulic calcium phosphate paste is injected through a small bore needle into the bone. The injectability of these pastes is relatively poor, resulting into partial injection only. In earlier studies we have shown that phase separation brings the injection process to a halt. Phase separation is characterized by a faster flow of the liquid than of the solid during paste extrusion. So far it is unclear whether or not particle separation contributes to the poor injectability of such hydraulic pastes. It is hypothesized that fine particles behave like a liquid and thus separate under the injection pressure, leaving larger particles behind. A factorial experimental design was used to examine this hypothesis. The particle size distribution (PSD) of the extrudate was measured over the course of each injection experiment using laser diffraction. The solid content of the paste was further inspected using scanning electron microscopy. A total of 48 experiments covering four factors at two levels each were performed. One factor was the ultrasound exposure duration, to ensure the dispersion quality of the particles during the PSD measurements. Another factor was the location of the samples over the course of the injection, so as to compare the extrudate with the PSDs remaining in the syringe. The liquid:powder ratio (LPR) in the injected paste was another factor investigated. Specifically, two different pastes with 40% and 50% LPR were examined. The dispersal medium was a fourth factor investigated, to ensure adequate dispersion of the particles during the PSD measurements. Analysis of variance showed that sample location did not significantly affect PSD. No apparent PSD change for the extruded paste and the paste remaining in the syringe could be detected by scanning electron microscopy. In conclusion, the present study did not show any evidence suggesting that particle separation occurred over the course of injection and thus that phase separation remains the main phenomenon leading to the poor injectability of CPCs.

Effect of modulated ultrasound parameters on ultrasound-induced thrombolysis

The potential of ultrasound to enhance enzyme-mediated thrombolysis by application of constant operating parameters (COP) has been widely demonstrated. In this study, the effect of ultrasound with modulated operating parameters (MOP) on enzyme-mediated thrombolysis was investigated. The MOP protocol was applied to an in vitro model of thrombolysis. The results were compared to a COP with the equivalent soft tissue thermal index (TIS) over the duration of ultrasound exposure of 30 min (p < 0.14). To explore potential differences in the mechanism responsible for ultrasound-induced thrombolysis, a perfusion model was used to measure changes in average fibrin pore size of clot before, after and during exposure to MOP and COP protocols and cavitational activity was monitored in real time for both protocols using a passive cavitation detection system. The relative lysis enhancement by each COP and MOP protocol compared to alteplase alone yielded values of 33.69 ± 12.09% and 63.89 ± 15.02% in a thrombolysis model, respectively (p < 0.007). Both COP and MOP protocols caused an equivalent significant increase in average clot pore size of 2.09 × 10−2 ± 0.01 µm and 1.99 × 10−2 ± 0.004 µm, respectively (p < 0.74). No signatures of inertial or stable cavitation were observed for either acoustic protocol. In conclusion, due to mechanisms other than cavitation, application of ultrasound with modulated operating parameters has the potential to significantly enhance the relative lysis enhancement compared to application of ultrasound with constant operating parameters.