Ultrasound-induced Changes Research Articles

Study on the effects and mechanisms of ultrasound on the peptide profile and taste of unsmoked bacon using peptidomics and bioinformatics

The ultrasound-induced impacts on the peptide characteristics and taste of unsmoked bacon have been evaluated through the use of peptidomics and bioinformatics approaches. Furthermore, the effect of such ultrasound-induced changes on the main endogenous proteases responsible for peptide generation was also investigated. In fact, the activity of main endogenous proteases was significantly increased after ultrasonic treatment during the processing of unsmoked bacon, and contributed to an increased number and an enhanced LFQ intensity of peptides. Besides, such increased amount of peptides and LFQ intensity with up to 500 W ultrasonic treatment were beneficial for the taste improvement of the final products as shown by taste prediction analysis. Nevertheless, an excessive ultrasonic power like 750 W hindered protein hydrolysis and further exerted a negative effect on peptide generation. Therefore, ultrasound under controlled conditions could be considered as a promising way to improve the taste of unsmoked bacon.

Ultrasound-induced changes in rheological behavior and hydrophobic microdomains of Lignosus rhinocerotis polysaccharide

Ultrasound is increasingly applied to modify the structures and physicochemical properties of polysaccharides. Hence, this work investigated the ultrasound-induced changes in the rheological behavior and hydrophobic microdomains of Lignosus rhinocerotis polysaccharide (LRP). With an increase in ultrasonic time, the apparent viscosity, storage modulus, loss modulus, and the final percentage recovery of LRP/water system increased to reach the maximum after 10 min treatment and then decreased. These results indicated that short-term (10 min) ultrasound could increase the strength of the network structure of LRP/water system, while longer-term ultrasound (30 and 60 min) weakened the network structure. The self-healing properties of LRP/water system was not affected by ultrasound treatment according to repeated strain and time sweep data. The critical aggregation concentration of the LRP/water system decreased from 2.5 to 1.8 mg/mL after 10 min ultrasound and the number of hydrophobic microdomains increased, suggesting that ultrasound promoted the hydrophobic aggregation of LRP.

Ultrasound-assisted assembly of β-lactoglobulin and chlorogenic acid for non covalent nanocomplex: fabrication, characterization and potential biological function

It is essential to understand the ultrasound-induced changes in assembly of proteins and polyphenols into non covalent nanocomplex. β-Lactoglobulin (LG) and chlorogenic acid (CA) with various biological activities can be combined to form food-grade nanocomplexes. This study systematically explored the role of high-intensity ultrasound pretreatment on the binding mechanisms of LG and CA, and the potential biological function for embedding curcumin (Cur). The scanning electron microscopy (SEM) revealed that ultrasound treatment could destroy the structure of LG, and the particle size of the protein was reduced to<50 nm. The change in secondary structure of the protein by ultrasound treatment could be revealed by the fourier transform infrared (FTIR) and fluorescence spectra. Besides, it was found that LG and CA were combined to form a complex under the hydrophobic interaction, and CA was bound in the internal cavity of LG with a relatively extended conformation. The result demonstrated that the ratio of Cur embedded in the ultrasonic sample could be effectively increased by 7% − 10%, the particle size in the emulsion was smaller, and the dispersion was more stable. This work contributes to the development of protein–polyphenol functional emulsion systems with the ability to deliver Cur.

Ultrasonic pre-treatment modifies the pH-dependent molecular interactions between β-lactoglobulin and dietary phenolics: Conformational structures and interfacial properties

There is a need to understand the ultrasound-induced changes in the interactions between proteins and phenolic compounds at different pH. This study systematically explored the role of high-intensity ultrasound pre-treatment on the binding mechanisms of β-lactoglobulin (β-LG) to two common phenolic compounds, i.e., (−)-epigallocatechin-3-gallate (EGCG) and chlorogenic acid (CA) at neutral and acidic pH (pH 7.2 and 2.4). Tryptophan fluorescence revealed that compared to proteins sonicated at 20% and 50% amplitudes, 35%-amplitude ultrasound pre-treatment (ULG-35) strengthened the binding affinities of EGCG/CA to β-LG without altering the main interaction force. After phenolic addition, ULG-35 displayed a similar but a greater extent of protein secondary and tertiary structural changes than the native protein, ascribed to the ultrasound-driven hydrophobic stacking among interacted molecules. The dominant form of β-LG (dimer/monomer) played a crucial role in the conformational and interfacial properties of complexes, which can be explained by the distinct binding sites at different pH as unveiled by molecular docking. Combining pre-ultrasound with EGCG interaction notably increased the foaming and emulsifying properties of β-LG, providing a feasible way for the modification of bovine whey proteins. These results shed light on the understanding of protein–phenolic non-covalent binding under ultrasound and help to develop complex systems with desired functionality and delivery.

Point-of-care ultrasound induced changes in management of unselected patients in the emergency department - a prospective single-blinded observational trial

BackgroundPoint-of-Care ultrasound (POCUS) changes the management in specific groups of patients in the Emergency Department (ED). It seems intuitive that POCUS holds an unexploited potential on a wide variety of patients. However, little is known about the effect of ultrasound on the broad spectrum of unselected patients in the ED. This study aimed to identify the effect on the clinical management if POCUS was applied on unselected patients. Secondarily the study aimed to identify predictors of ultrasound changing management.MethodsThis study was a blinded observational single center trial. A basic whole body POCUS protocol was performed in extension to the physical examination. The blinded treating physicians were interviewed about the presumptive diagnosis and plan for the patient. Subsequently the physicians were unblinded to the POCUS results and asked to choose between five options regarding the benefit from POCUS results.ResultsA total of 403 patients were enrolled in this study. The treating physicians regarded POCUS examinations influence on the diagnostic workup or treatment as following: 1) No new information: 249 (61.8%), 2) No further action: 45 (11.2%), 3) Further diagnostic workup needed: 52 (12.9%), 4) Presumptive diagnosis confirmed 38 (9.4%), and 5) Immediate treatment needed: 19 (4.7%). Predictors of beneficial ultrasound were: (a) triage > 1, (b) patient comorbidities (cardiac disease, hypertension or lung disease), or (c) patients presenting with abdominal pain, dyspnea, or syncope.ConclusionPOCUS was found to be potentially beneficial in 27.0% of all patients. High triage score, known cardiac disease, hypertension, pulmonary diseases, a clinical presentation with abdominal pain, dyspnea, or syncope are predictors of this. Future research should focus on patient-important outcomes when applying POCUS on these patients.Trial registrationThe trail was registered prior to patient inclusion with the Danish Data Protection Agency (https://www.datatilsynet.dk/ Case no: 1–16–02-603-14) and Clinical Trials (www.clinicaltrials.gov/ Protocol ID: DNVK1305018).

Ultrasound-Driven Improvement of Foamability in Beverage Proteins

This study investigates the effect of ultrasound treatment on the foamability of proteins used in beverages, aiming to enhance their foaming properties for improved product quality. Ultrasound, known for its ability to induce physical and chemical changes in materials, was applied to protein solutions under various conditions to evaluate its impact on foam formation and stability. Beverage proteins, such as whey and soy proteins, were subjected to ultrasound at different frequencies and intensities, and their foamability was assessed through measurements of foam volume, stability, and bubble size distribution. The results demonstrate that ultrasound treatment significantly enhances the foamability of beverage proteins. The application of ultrasound led to a notable increase in foam volume and stability, with optimized conditions resulting in finer bubble sizes and improved foam structure. These improvements are attributed to ultrasound-induced changes in protein structure, which enhance protein-protein interactions and promote more stable foam formation. The study also explores the relationship between ultrasound parameters and foaming properties, identifying the optimal conditions for maximizing foamability. Additionally, the effects of ultrasound on the functional properties of proteins, such as solubility and viscosity, were examined to ensure that foam enhancement does not compromise other desirable characteristics. Overall, the findings suggest that ultrasound treatment is a promising technique for improving the foamability of beverage proteins, offering potential benefits for the production of beverages with enhanced texture and visual appeal. This research provides a foundation for further exploration of ultrasound applications in beverage technology and contributes to the development of innovative approaches for optimizing protein-based foams.

Effect of ultrasound on physicochemical and foaming properties of a protein concentrate from giant squid (Dosidicus gigas) mantle

Giant squid (Dosidicus gigas) proteins have appropriate functional properties, albeit of smaller magnitude in comparison to other marine species. Therefore, this research characterizes the ultrasound-induced (20 kHz; 20 and 40% amplitude; 0, 1, 3 and 5 min) changes to the physicochemical and foaming properties of mantle proteins. The changes in pH, electrophoretic profile, viscosity, surface hydrophobicity, particle size and zeta potential, as well as foaming capacity and stability were evaluated. A slight decrease (p ≥ 0.05) in the pH occurred as the ultrasound time increased. While no changes in SDS-PAGE (reducing and non-reducing) were detected, native PAGE revealed new bands. Ultrasound increased the viscosity and surface hydrophobicity, and decreased the particle size and net surface charge. Moreover, foaming capacity was improved and foaming stability was maintained at 100% for 1 h. Therefore, the application of ultrasound represents an alternative to improve the foaming properties.

Insight into mass transfer during ultrasound-enhanced adsorption/desorption of blueberry anthocyanins on macroporous resins by numerical simulation considering ultrasonic influence on resin properties

The mass transfer mechanism about ultrasonic enhancement of blueberry anthocyanin adsorption and desorption on macroporous resins were investigated. Ultrasound treatment led to the decrease of resin size, whereas average pore diameter, specific surface area, total pore volume were less affected. Then, the pore volume and surface diffusion model considering ultrasound-induced changes of particle size and surface area was employed to model anthocyanin adsorption process numerically. Generally, sonication enhanced external mass transfer coefficient (kL) and surface diffusion coefficient (Ds) during adsorption. The values of kL and Ds under sonication at 279 W/L and 20 °C were 7.578 × 10−2 cm/s and 2.000 × 10−9 cm2/s, which were 2.0% and 140.1% higher than the kL and Ds values under orbital agitation at 20 °C. Accordingly, anthocyanins penetrated into the interior of macroporous resins faster under sonication. The overall intraparticle diffusion for anthocyanin adsorption was dominated by pore volume diffusion with the contribution percentage higher than 50%. Sonication enhanced the contribution of surface diffusion to the overall diffusion, which was consistent with the increase of Ds with ultrasound energy. Moreover, a general diffusion model also incorporating the variations of particle size and surface area was utilized to model anthocyanin desorption process. The overall anthocyanin diffusivity increased with both ultrasound energy level and temperature. Anthocyanins distributed more homogenously inside resins under sonication at 279 W/L than under other treatments. This work could be a reference for the valorization of anthocyanins in food industry, especially juice and wine industries.

Ultrasound-mediated interfacial protein adsorption and fat crystallization in cholesterol-reduced lard emulsion.

Lard with a substantially reduced cholesterol content through aqueous enzyme extraction is an attractive source of lipid in healthy and nutritious emulsion food product development. The objective of this study was to elucidate the crystallization behavior (4-20 °C) of emulsions prepared from low-cholesterol lard in relation to protein emulsifier (2 and 4% whey protein isolate, WPI) and ultrasound (475 w, 5 min) treatments. The physicochemical properties and fat crystallization pattern of the emulsions were investigated. Emulsions with 4% WPI were superior to those with 2% WPI on interfacial adsorption and crystal size reduction. Ultrasonic treatment of prepared emulsions further decreased fat crystal size, promoted small and uniform crystal distribution, and slightly destabilized emulsions. Protein concentration and ultrasonic treatment had no obvious effect on crystal transition from β' to the more stable β-form based on X-ray diffraction. The melting properties determined by differential scanning calorimetry indicated that emulsified lard had a lower onset melting temperature than bulk lard, and with ultrasound treatment, the melting enthalpy increased remarkably. The ultrasound-induced change in fat crystalline structure and emulsion meta-stability may be valuable to the manufacture of healthy, emulsion-incorporated food products.

Thiamine and benfotiamine counteract ultrasound-induced aggression, normalize AMPA receptor expression and plasticity markers, and reduce oxidative stress in mice

The negative societal impacts associated with the increasing prevalence of violence and aggression is increasing, and, with this rise, is the need to understand the molecular and cellular changes that underpin ultrasound-induced aggressive behavior. In mice, stress-induced aggression is known to alter AMPA receptor subunit expression, plasticity markers, and oxidative stress within the brain. Here, we induced aggression in BALB/c mice using chronic ultrasound exposure and examined the impact of the psychoactive anti-oxidant compounds thiamine (vitamin B1), and its derivative benfotiamine, on AMPA receptor subunit expression, established plasticity markers, and oxidative stress. The administration of thiamine or benfotiamine (200 mg/kg/day) in drinking water decreased aggressive behavior following 3-weeks of ultrasound exposure and benfotiamine, reduced floating behavior in the swim test. The vehicle-treated ultrasound-exposed mice exhibited increases in protein carbonyl and total glutathione, altered AMPA receptor subunits expression, and decreased expression of plasticity markers. These ultrasound-induced effects were ameliorated by thiamine and benfotiamine treatment; in particular both antioxidants were able to reverse ultrasound-induced changes in GluA1 and GluA2 subunit expression, and, within the prefrontal cortex, significantly reversed the changes in protein carbonyl and polysialylated form of neural cell adhesion molecule (PSA-NCAM) expression levels. Benfotiamine was usually more efficacious than thiamine. Thus, the thiamine compounds were able to counteract ultrasound-induced aggression, which was accompanied by the normalization of markers that have been showed to be associated with ultrasound-induced aggression. These commonly used, orally-active compounds may have considerable potential for use in the control of aggression within the community.This article is part of the Special Issue entitled ‘Current status of the neurobiology of aggression and impulsivity’.

Ultrasound-induced changes in structural and physicochemical properties of β-lactoglobulin.

Effect of ultrasound treatment on the physicochemical properties and structure of β‐lactoglobulin were investigated. β‐Lactoglobulin was treated with ultrasound at different amplitudes, temperatures, and durations. The surface hydrophobicity and free sulfhydryl group of β‐lactoglobulin were significantly increased after ultrasound treatment (p < .05). The maximal surface hydrophobicity and free sulfhydryl group were 5,812.08 and 5.97 μmol/g, respectively. Ultrasound treatment changed the physicochemical properties of β‐lactoglobulin including particle size (from 1.21 ± 0.05 nm to 1.66 ± 0.03 nm), absolute zeta potential (from 15.47 ± 1.60 mV to 27.63 ± 3.30 mV), and solubility (from 84.66% to 95.17%). Ultrasound treatment increased α‐helix and β‐sheet structures of β‐lactoglobulin. Intrinsic fluorescence intensity of ultrasound‐treated β‐lactoglobulin was increased with shift of λmax from 334 to 329 nm. UV absorption of β‐lactoglobulin was decreased with shift of λmax from 288 to 285 nm after ultrasound treatment. There were no significant changes in high‐performance liquid chromatography and protein electrophoretic patterns. These findings indicated that ultrasound treatment had high potential in modifying the physiochemical and structural properties of β‐lactoglobulin for industrial applications.

Impact of acoustic cavitation on food emulsions

The work explores the experimental and theoretical aspects of emulsification capability of ultrasound to deliver stable emulsions of sunflower oil in water and meat sausages. In order to determine optimal parameters for direct ultrasonic emulsification of food emulsions, a model was developed based on the stability of emulsion droplets in acoustic cavitation field. The study is further extended to investigate the ultrasound induced changes to the inherent properties of raw materials under the experimental conditions of sono-emulsification.

Ultrasound improves the renneting properties of milk

The effects of ultrasound application on skim milk (10% w/w total solids at natural pH 6.7 or alkali-adjusted to pH 8.0) prior to the renneting of milk at pH 6.7 were examined. Skim milk, made by reconstituting skim milk powder, was sonicated at 20kHz and 30°C (dissipated power density 286kJkg−1) in an ultrasonic reactor. The rennet gelation time, curd firming rate, curd firmness, and the connectivity of the rennet gel network were improved significantly in rennet gels made from milk ultrasonicated at pH 8.0 and re-adjusted back to pH 6.7 compared to those made from milk sonicated at pH 6.7. These renneting properties were also improved in milk sonicated at pH 6.7 compared to those of the non-sonicated control milk. The improvements in renneting behavior were related to ultrasound-induced changes to the proteins in the milk. This study showed that ultrasonication has potential to be used as an intervention to manipulate the renneting properties of milk for more efficient manufacturing of cheese.

Biophysical studies of the effect of high power ultrasound on the DNA solution

Stability and molecular size of the DNA double helical structure were studied on an aqueous solution of DNA after exposure to high power doses of continuous wave ultrasound at frequency of 20 kHz. Thermal transition spectrophotometry (UV-melting), constant-field gel electrophoresis (CFGE), differential scanning calorimetry (DSC) and dielectric properties measurements were used to evaluate the ultrasound-induced changes in the DNA double helical structure. The thermal transition spectrophotometry (UV-melting) and differential scanning calorimetry (DSC) results showed that ultrasound power caused loss of DNA double helical structure and the DNA double strands melting temperature decreased as the ultrasound power increased, indicating a decrease in the stability of the double helical structure of DNA. The constant-field gel electrophoresis (CFGE) results showed that the molecular size of the DNA fragments decreased as the ultrasound power increased. The dielectric data in the frequency range from 20 Hz to 100 kHz for the native DNA showed that dispersion at frequency of about 500 Hz resulted from polarization induced by counterions. The decrease in the dielectric increment indicated a decrease in length of DNA molecule after exposure to ultrasound power.

Kinetics and Mechanism of Bacterial Inactivation by Ultrasound Waves and Sonoprotective Effect of Milk Components

Inactivation of Escherichia coli and Listeria monocytogenes were investigated in buffer and milk upon treatment with ultrasound waves (USW). In addition, sonoprotective effect of milk components and ultrasound-induced changes in bacterial cells were investigated using scanning electron microscopy (SEM). Bacterial cells were added to phosphate buffer, whole milk, skim milk, or simulated milk ultrafiltrate (SMUF). To determine the sonoprotective effect of milk components, lactose (5%), casein (3%), or β lactoglobulin (0.3%) was added to SMUF. Samples were sonicated with 24 kHz pulse USW while maintaining the system temperature between 30 to 35 °C. Aliquots were drawn at set times during sonication and bacteria were enumerated by surface plating appropriate dilutions on selective and nonselective media plates. Escherichia coli exhibited significantly higher D values in whole (2.43 min) and skim milk (2.41 min) than phosphate buffer (2.19 min). Listeria monocytogenes also showed higher D values in whole (9.31 min) and skim milk (8.61 min) compared to phosphate buffer (7.63 min). Data suggest that milk exerts a sonoprotective effect on these bacteria. Escherichia coli exhibited a log-linear inactivation kinetics followed by tailing whereas L. monocytogenes showed 1st-order kinetics throughout. Among the milk components tested, presence of lactose in SMUF resulted in significantly higher D values than SMUF for both organisms suggesting that lactose was exerting a protective effect on bacteria. SEM images showed that USW caused mechanical damage to the cell wall and cell membrane of bacteria leading to their inactivation.

Electrical Response of Planar Lipid Bilayers to Ultrasound

Recent results in vitro and in vivo demonstrate that application of low-frequency ultrasound to neurons leads to activation of voltage-gated sodium channels (Nav channels), thereby increasing the rate of action potential firing. These results suggest that modulation of brain activity by transcranial ultrasound may facilitate radical new approaches to behavioral neuroscience and treatment of neurological disorders. However, it is unclear what the mechanistic basis of this effect is, or even whether it represents a direct action of ultrasound on Nav channels. To help answer these questions, and to better understand the interactions of ultrasound with membrane proteins in general, we have studied the electrical response of planar lipid bilayers under voltage-clamp to ultrasound (1 MHz). The response to sufficiently long ultrasound pulses consists of distinct dynamic “on” and “off” components with no apparent steady-state effects. The on and off responses are exponentially decaying sinusoidal current oscillations about the baseline level, and are identical except for the polarity of the current. For bilayers made of POPE and POPG (3:1 by weight), the frequency and decay constant of the on and off responses are approximately 1070 Hz and 610 s−1. The current oscillation is dependent on the lipid composition of the bilayer, with bilayers made from cholesterol having higher frequency and larger decay constants. The electrical response is probably a capacitive current (under voltage-clamp, IC = V(dC/dt)) due to distortions of bilayer structure by ultrasonic radiation force. We hypothesize that ultrasound-induced changes in bilayer structure may alter the activity of membrane proteins by changing the contribution of protein/bilayer hydrophobic mismatch to the free energy difference between protein conformations. This mechanism could underlie the activation of neuronal Nav channels by ultrasound. The effects of ultrasound on hydrophobic mismatch can be investigated using gramicidin channels.

Ultrasound-induced changes in mesostructure of amorphous iron (III) hydroxide xerogels: A small-angle neutron scattering study

Structure and thermal properties of iron (III) hydroxide xerogels obtained under high intensity ultrasonic treatment were studied by means of small-angle neutron scattering and heat-flux calorimetry. It was established that sonication affects the mesostructure of amorphous xerogels (i.e., increase in their homogeneity, surface fractal dimension, and the sizes of aggregates of primary particles) as opposed to the commonly accepted point of view that ultrasonic action cannot lead to notable changes in structure of powders, consisting of nanometer size particles. Ultrasonically induced structural changes in xerogels are evidently confirmed via their notably different reactivity at thermal decomposition under hydrothermal conditions.

Ultrasound-induced change in chemical properties of petroleum products

Approaches to chemical modification of petroleum products are examined, and a method of lowering sulfur content using high-intensity ultrasonic vibrations is proposed. Experiments with the use of specially constructed devices for ultrasonic treatment of petroleum products have indicated the principal feasibility of lowering sulfur content in crude. It is established that the best means of removing sulfur from petroleum products is stepwise periodic treatment in an ultrasound field with subsequent removal of the cleaned portion of the crude.

Spatiotemporal Effects of Sonoporation Measured by Real-Time Calcium Imaging

To investigate the effects of sonoporation, spatiotemporal evolution of ultrasound-induced changes in intracellular calcium ion concentration ([Ca 2+] i) was determined using real-time fura-2AM fluorescence imaging. Monolayers of Chinese hamster ovary (CHO) cells were exposed to a 1-MHz ultrasound tone burst (0.2 s, 0.45 MPa) in the presence of Optison ™ microbubbles. At extracellular [Ca 2+] o of 0.9 mM, ultrasound application generated both nonoscillating and oscillating (periods 12 to 30 s) transients (changes of [Ca 2+] i in time) with durations of 100–180 s. Immediate [Ca 2+] i transients after ultrasound application were induced by ultrasound-mediated microbubble–cell interactions. In some cases, the immediately affected cells did not return to pre-ultrasound equilibrium [Ca 2+] i levels, thereby indicating irreversible membrane damage. Spatial evolution of [Ca 2+] i in different cells formed a calcium wave that was observed to propagate outward from the immediately affected cells at 7–20 μm/s over a distance >200 μm, causing delayed transients in cells to occur sometimes 60 s or more after ultrasound application. In calcium-free solution, ultrasound-affected cells did not recover, consistent with the requirement of extracellular Ca 2+ for cell membrane recovery subsequent to sonoporation. In summary, ultrasound application in the presence of Optison ™ microbubbles can generate transient [Ca 2+] i changes and oscillations at a focal site and in surrounding cells via calcium waves that last longer than the ultrasound duration and spread beyond the focal site. These results demonstrate the complexity of downstream effects of sonoporation beyond the initial pore formation and subsequent diffusion-related transport through the cellular membrane. (E-mail address: cxdeng@umich.edu)

Direct action on the molecule is one of several mechanisms by which ultrasound enhances the fibrinolytic effects of reteplase

Enhanced fibrinolytic reperfusion therapy may improve the outcome in embolic stroke, where ultrasound exposure has been shown to be one option. We recently verified that the fibrinolytic properties of streptokinase were modulated following ultrasound exposure of the molecule. We have now explored this possibility following ultrasound exposure of the reteplase molecule. The effects on clot lysis of reteplase and ultrasound both separately and in combination were studied by evaluating cumulated release of haemoglobin from whole blood clots following 1 h of exposure. Specifically, we investigated how clot lysis was modulated following pulsed 1 MHz ultrasound pre-exposure of the reteplase solution at intensities ranging between 0.125 and 4 W/cm2 spatial-average temporal-average intensity (SATA) and the effects of reteplase following 1 h of pre-exposure of clots to ultrasound at high intensity (4 W/cm2SATA). Significant enhancement of clot lysis during concomitant reteplase and pulsed ultrasound exposure were observed in two intensity ranges: 0.125-0.25 and 2-4 W/cm2SATA. Pre-exposing reteplase solution to ultrasound significantly increased clot lysis only in the lower intensity range. At high ranges, pre-exposure of clots to ultrasound was followed by an increased fibrinolytic action of reteplase. Pre-exposing reteplase solution to low-intensity ultrasound induced changes in the reteplase molecule that enhanced its fibrinolytic effects. Although this effect disappeared at moderately higher ultrasound intensity, the pre-exposure of clots to ultrasound of higher intensity induced increased fibrinolytic effects of reteplase solution.