Application Of Ultrasound Energy Research Articles

Application of Augmented Water Flooding Using Ultrasound Energy to Improve Oil Recovery

The application of ultrasound energy in improving oil recovery is an emerging technique, it has been tested in laboratories and some field applications in different parts of the world. In this study, Nigerian crude oil of 4.21 cSt viscosity and sandstone rock samples were tested using a designed and constructed experimental rig. The rig is an analogue of a standard core flooding set up and works on the principle of fluid flow in porous media. Furthermore, a modeled equation was developed to better understand the effects of power and time on the volume of oil recovered at a constant ultrasound frequency. Results obtained show a positive impact in the recovery of residual oil during waterflooding with the assisted ultrasound energy. About 2-fold increase in the recovery of oil was observed when the ultrasound energy was applied to augment the waterflooding process. Model equations developed were found to be adequate because the adjusted and predicted R-squared values show reasonable agreement (R-adjusted = 0.9993, R-Predicted = 0.9974).

Application of Augmented Water Flooding Using Ultrasound Energy to Improve Oil Recovery

The application of ultrasound energy in improving oil recovery is an emerging technique, it has been tested in laboratories and some field applications in different parts of the world. In this study, Nigerian crude oil of 4.21 cSt viscosity and sandstone rock samples were tested using a designed and constructed experimental rig. The rig is an analogue of a standard core flooding set up and works on the principle of fluid flow in porous media. Furthermore, a modeled equation was developed to better understand the effects of power and time on the volume of oil recovered at a constant ultrasound frequency. Results obtained show a positive impact in the recovery of residual oil during waterflooding with the assisted ultrasound energy. About 2-fold increase in the recovery of oil was observed when the ultrasound energy was applied to augment the waterflooding process. Model equations developed were found to be adequate because the adjusted and predicted R-squared values show reasonable agreement (R-adjusted = 0.9993, R-Predicted = 0.9974).

Viscosity and thermal kinetics of 10 preheated restorative resin composites and effect of ultrasound energy on film thickness

ObjectiveThis study investigated viscosity and thermal kinetics of 10 selected preheated restorative resin composites and the effect of ultrasound energy on film thickness. MethodsA range of different resin composites was tested: Charisma Diamond, IPS Empress Direct, Enamel Plus HRi, Essentia, Estelite Omega, Filtek Z100, Filtek Z350 XT, Gradia, TPH Spectrum and VisCalor. A flowable resin composite (Opallis Flow) and two resin cements (RelyX Veneer, Variolink Esthetic LC) also were tested. Viscosity (Pa s) was measured at 37 °C and 69 °C (preheating temperature) using a rheometer. Film thickness (μm) was measured before and after application of ultrasound energy. Temperature loss within resin composite following preheating (°C/s) was monitored. Data were statistically analyzed (α = 0.05). ResultsViscosity at 69 °C was lower than at 37 °C for all materials except the flowable resin composite. Preheating reduced viscosity between 47% and 92% for the restorative resin composites, which were generally more viscous than the flowable materials. Film thickness varied largely among materials. All preheated resin composites had films thicker than 50 μm without ultrasound energy. Application of ultrasound reduced film thickness between 21% and 49%. Linear and nonlinear regressions did not identify any relationship between filler loading, viscosity, and/or film thickness. All materials showed quick temperature reduction following preheating, showing maximum temperature loss rates after approximately 10 s. SignificanceDistinct restorative resin composites react differently to preheating, affecting viscosity and film thickness. The overall performance of the preheating technique depends on proper material selection and use of ultrasound energy for reducing film thickness.

Application of ultrasound energy in surgical treatment of chronic hemorrhoids Stages III-IV

Objective. Improvement of quality of the patients’ treatment, who suffer chronic hemorrhoids Stages III-IV, applying ultrasound energy intraoperatively.
 Materials and metods. The results of treatment are presented of 129 patients, suffering chronic hemorrhoids Stages III-IV: in 58 of them ultrasound energy was applied (Group I - the main), and in 71 - a standard procedure was performed (Group II - a control one).
 Results. Average duration of the operation have constituted in patients of Group I - (15.8 ± 1.7) min, and in Group II - (38.6 ± 1.5) min (p < 0.05). Postoperatively the patients of Group I have complained of pain during (3.4 ± 0.2) days, while in the Group II - during (7.5 ± 0.5) days (p < 0.05). In the patients of Group I only nonnarcotic analgetics during (3.4 ± 0.2) days; while in the Group II narcotic preparations were needed (2.1 ± 0.2) days, and nonnarcotic - (5.4 ± 0.3) days. Postoperatively in the Group II patients the pain syndrome level on the first day have constituted (9.1 ± 0.4) points, what is in 2.4 times higher, than in Group I (p < 0.05). Average stationary stay have constituted in the operated patients of Group I (2.8 ± 0.2) days, and in the Group II - (4.3 ± 0.4) days (p < 0.05).
 Conclusion. Application of the ultrasound energy permits to shorten the operation duration, average duration of stationary stay of the patients, and to reduce the pain syndrome level. Also, while application of ultrasound, the necessity to use narcotic analgetics postoperatively is eliminated. The quality of life indices during 6 mo postoperatively were better in the patients, who were operated, using ultrasound, than in those, to whom classic hemorrhoidectomy was performed.

Hypotension and Bradycardia Produced by Transthoracic Application of Low-Intensity Ultrasound Therapy in Hearts of Healthy Rats - A Preclinical Study.

ObjectiveTo investigate the cardiovascular effects produced by transthoracic application of low-intensity pulsed ultrasound therapy (LIPUST).MethodsThree-month-old male Wistar rats (± 300 g, N=16) were randomly allocated in two groups, namely SHAM (control group, faked procedures) and UST (animals treated with LIPUST). These animals, under anesthesia, were instrumented (femoral artery and vein catheterization) for hemodynamic recordings (mean blood pressure [MBP], heart rate [HR]) and blood biochemical profile (lipids, creatine kinase-myocardial band [CK-MB]). Then, LIPUST (spatial average-temporal average [ISATA] 1-MHz, power 0.1 to 1.2 W/cm2, pulsed 2:8 ms, cycle at 30%, for three minutes) was applied to animals from the UST group, externally to their thorax. SHAM animals were equally manipulated, but without application of ultrasound energy. After the hemodynamic and biochemical measurements, animals were sacrificed, and their hearts were mounted in a Langendorff apparatus for coronary reactivity evaluation. Standard histology techniques were employed to analyze the hearts.ResultsLIPUST application caused statistically significant reductions in MBP (92±4 vs. 106±1 mmHg) and HR (345±14 vs. 380±17 rpm) when compared with SHAM procedures. UST rats exhibited higher CK-MB levels (318±55 vs. 198±26 U/dL) and lower plasma triglycerides levels (38±7 vs. 70±10 mg/dL) than SHAM animals. Coronary reactivity was not significantly changed by LIPUST. Cardiac histopathology showed an increase in capillary permeability in treated animals when compared with SHAM animals.ConclusionNoninvasive LIPUST induces significant metabolic and hemodynamic changes, including intensity-dependent bradycardia and hypotension, indicating a possible therapeutic effect for cardiac events.

Effects of ultrasound energy on the porcine corneal endothelium - Establishment of a phacoemulsification damage model.

The purpose of this study was to establish a standardized in vitro phacoemulsification damage model for future investigations of the effects of phacoemulsification, surgical devices, protective ophthalmic viscoelastic devices (OVDs), irrigation solutions and other aspects related to cataract phacoemulsification surgery on the corneal endothelium using porcine eyes. Thirty-four porcine eyes were randomly assigned to three groups (phacoemulsification (n=13), irrigation (n=9), control (n=12)). A total of 5min of ultrasound energy with intermittent irrigation/aspiration was applied in the eyes of the phacoemulsification group. The eyes of the irrigation group received the identical treatment, but without the application of ultrasound energy. The control group was left untreated. All eyes were then prepared to split corneal buttons followed by 15days of cultivation. Endothelial cell density (ECD) was assessed blinded on day 15. Endothelial cell density declined significantly more until day 15 in the phacoemulsification group (2567±317/267 cells/mm² (median±25%/75%-quartiles), -32.5±7.0/6.4%) compared to the irrigation (3450±350/383 cells/mm², -11.8±5.3/2.6%; p<0.001) and the control group (3650±288/258 cells/mm², -10.2±3.2/4.6%; p<0.001). The phacoemulsification damage model presented in this study is sensitive to phacoemulsification energy and may reliably be used to investigate various factors involved in phacoemulsification with regard to their influence on corneal endothelial cells. This method is able to replace animal experiments or in vitro cell culture experiments that often do not translate well to the in vivo situation in humans.

Oxidative desulfurization of diesel fuel oil using supported Fenton catalysts and assisted with ultrasonic energy

An ultrasound-assisted heterogeneous catalytic oxidation process was applied to eliminate sulfur from commercial diesel fuel oil. The studied variables were catalyst concentration, type of catalyst (homogeneous or heterogeneous), oxidizing agent concentration, and the application of ultrasound energy. Supported catalysts were prepared by impregnation of coal fly ash with an iron(II) sulfate aqueous solution using ultrasound energy. After drying, the catalyst was calcined at 500 °C for 4 h. The oxidizing agent was hydrogen peroxide. Ultrasound energy was applied with a frequency of 47 kHz and an intensity of 147 W. Ethanol was employed for extracting the oxidized compounds from the hydrocarbon mixture. Coal fly ash and ethanol were used with the purpose of applying low-cost raw materials in chemical processes. It was found that under the studied conditions, increasing oxidizing agent concentration and the application of ultrasound energy can enhance the sulfur removal from commercial diesel fuel oil. Catalyst concentration did not play a significant role in the process. Similar results were obtained using homogeneous or heterogeneous catalyst, which is important since the heterogeneous catalyst could be recovered, reactivated, and used in many cycles.

Ultrasound-assisted solvent extraction of porous membrane packed solid samples: A new approach for extraction of target analytes from solid samples

For the first time, a porous membrane-based method is proposed for the extraction of target analytes directly from the solid samples. This method involves the packing of solid sample inside a porous polypropylene membrane sheet whose edges are heat-sealed to fabricate a bag. This bag is immersed in a suitable solvent and the analytes are extracted by the application of ultrasound energy. The various factors that affect the extraction performance such as extraction solvent, ultrasonication time, and ultrasound power are suitably optimized. The scope of this extraction method is very general, it can be used for the extraction of different classes of analytes from a variety of solid samples using suitable extraction solvents. The beauty of this method lies in the fact that only the small molecules such as analytes can pass through the membrane while the interfering or complex matrix species cannot pass through the membrane bag to the extraction solvent. Previously, the solid samples were first digested/dissolved into liquid medium and then analytes were extracted by membrane-protected adsorbents involving adsorption and desorption steps. With the proposed procedure, the steps of digestion/dissolution and the adsorption of analytes onto a suitable adsorbent are eliminated. Likewise, the steps of filtration and centrifugation are not required as the solid is effectively packed inside the membrane bag. Moreover, the extraction device is low cost, portable, easy to fabricate, and simple to use in the extraction process. In this work, proof of the concept is demonstrated by the extraction of polyaromatic hydrocarbons from the soil samples using GC–MS. This method provided reasonably low LODs ranging from 0.19 to 0.93 ng/mg. The intra-day accuracy and precision ranged from 87.5 to 109% and 0.8 to 5%, respectively while recoveries varied from 75.1 ± 4.9 to 106 ± 4.5%.

Ultrasound-Induced Insulin Release as a Potential Novel Treatmentfor Type 2 Diabetes Mellitus.

Therapeutic ultrasound presents a potential novel treatment for type 2 diabetes mellitus that utilizes the non-invasive application of ultrasound energy to treat secretory defects in the earlier stages of the disease. Our previous studies have shown that ultrasound is capable of stimulating insulin release from pancreatic beta cells, safely and effectively. This study aims to both examine the calcium-dependent mechanisms of ultrasound-mediated insulin release from pancreatic beta cells using three complementary modalities - carbon fiber amperometry, ELISA studies, and Ca2+ fluorescence imaging - and to study the translational potential of therapeutic ultrasound using transgenic hyperglycemic mice for safety and efficacy studies.

Experimental investigation on the effect of ultrasonic waves on reducing asphaltene deposition and improving oil recovery under temperature control

A well-known complication in the oil reservoir during oil production is asphaltene deposition in and around the production wellbore. Deposition of asphaltene around the production wellbore may cause a significant pressure drop and in turn loss of efficiency in the production process. Various mechanical and chemical methods have been employed in order to reduce asphaltene formation or to eliminate the precipitate. A novel technique which presented a great potential for prevention or elimination of asphaltene is spreading out the high energy ultrasound wave within the oil reservoir. In this study, in a glass micro-model, asphaltene precipitation was first simulated in a transparent porous medium and its removal by application of high energy ultrasound wave was then investigated. To simulate asphaltene precipitation, the micro-model was first saturated with oil and then a normal-pentane was injected. This was followed by flooding the porous media with brine while propagating ultrasound waves (30 kHz and 100 W) to eliminate asphaltene precipitation. The experiment setup was equipped with a temperature controller. The results indicate a significant reduction in asphaltene precipitation in the oil reservoir may be achieved by application of ultrasound energy. Asphaltene particle deposition has been solved reversibly in the oil layer of porous medium and with the oil layering mechanism, the rate of oil production has been increased. In some spots, water/oil emulsion has been formed because of the ultrasonic vibration on the wall. Both the crude and synthetic oils were examined.

Study of a laboratory-scaled new method for the accelerated continuous ageing of wine spirits by applying ultrasound energy

During the ageing of brandies, many physicochemical processes take place involving the distilled spirit and the wood of the casks. Because of these reactions, the polyphenolic content of brandies and their content of organic acids increase with the ageing. These reactions are slow, and the ageing of high-quality brandies takes several years. In this paper, the development of a system that uses the circulation of the wine distillate through encapsulated American oak chips and the application of ultrasound energy with the aim of producing aged wine spirits has been carried out, and the influences of the operation variables over the characteristics of the produced drink have been measured. With that proposal, the influence of different powers of ultrasound, and also the influence of the movement of the liquor through oak chips, was determined first. This way, the results show that higher powers of ultrasound, of nearly 40W/L, in addition with the movement of the spirit, improve the extraction of phenolic compounds in a 33.94%, after seven days of ageing. Then, applying Youden and Steiner’s experimental design, eight experiments of ageing were performed, and the samples obtained by this new method were analysed to obtain information related to their physicochemical and oenological characterisation in order to determine the experimental conditions that produce the best ageing results. This way, the best spirit produced by this new method of ageing is obtained with a high alcoholic strength of the distilled wine and a high quantity of oak chips, and with room temperature and high flow rate. In addition, the presence of oxygen in the sample and the absence of light increase the quality of the produced spirit. Finally, the application of ultrasound energy in large pulses is related with the improvement of two important ageing markers: the intensity of the colour and the TPI. As a last experiment, we applied this ageing method to five varietal spirits. The sensorial analysis of aged samples showed the aged spirits had better ratings than the initial distilled wine.

The role of ultrasound in pharmaceutical production: sonocrystallization.

The main aim of this review was to develop a critical discussion of the key role ultrasound (US) can play on the production of active pharmaceutical ingredients (APIs) by discussing the versatile effect this type of energy produces. The different crystallization techniques that can be assisted and improved by US are discussed in the light of the available US devices and the effect pursued by application of US energy. Simple and complex analytical methods to monitor API changes are also discussed. The countless achievements of API US-assisted production are summarized in a table, and outstanding effects such as narrower particle size distribution; decreased particle size, induction time, metastable zone and supersaturation levels; or a solubility increase are critically discussed. The indisputable advantages of sonocrystallization over other ways of API production have been supported on multiple examples, and pending goals in this field (clarify the effect of US frequency on crystallization, know the mechanism of sonocrystallization, determine potential degradation owing to US energy, avoid calculation of the process yield by determining the concentration of the target drug remaining in the solution, etc.) should be achieved.

Minimizing antibody cross-reactivity in multiplex detection of biomarkers in paper-based point-of-care assays.

Highly multiplexed immunoassays could allow convenient screening of hundreds or thousands of protein biomarkers simultaneously in a clinical sample such as serum or plasma, potentially allowing improved diagnostic accuracy and clinical management of many conditions such as autoimmune disorders, infections, and several cancers. Currently, antibody microarray-based tests are limited in part due to cross reactivity from detection antibody reagents. Here we present a strategy that reduces the cross-reactivity between nanoparticle-bound reporter antibodies through the application of ultrasound energy. By this concept, it was possible to achieve a sensitivity 10(3)-fold (5 pg mL(-1)) lower than when no ultrasound was applied (50 ng mL(-1)) for the simultaneous detection of three different antigens. The detection limits and variability achieved with this technique rival those obtained with other types of multiplex sandwich assays.

Ultrasound-mediated oncolytic virus delivery and uptake for increased therapeutic efficacy: state of art.

The field of ultrasound (US) has changed significantly from medical imaging and diagnosis to treatment strategies. US contrast agents or microbubbles (MB) are currently being used as potential carriers for chemodrugs, small molecules, nucleic acids, small interfering ribonucleic acid, proteins, adenoviruses, and oncolytic viruses. Oncolytic viruses can selectively replicate within and destroy a cancer cell, thus making them a powerful therapeutic in treating late-stage or metastatic cancer. These viruses have been shown to have robust activity in clinical trials when injected directly into tumor nodules. However limitations in oncolytic virus’ effectiveness and its delivery approach have warranted exploration of ultrasound-mediated delivery. Gene therapy bearing adenoviruses or oncolytic viruses can be coupled with MBs and injected intravenously. Following application of US energy to the target region, the MBs cavitate, and the resulting shock wave enhances drug, gene, or adenovirus uptake. Though the underlying mechanism is yet to be fully understood, there is evidence to suggest that mechanical pore formation of cellular membranes allows for the temporary uptake of drugs. This delivery method circumvents the limitations due to stimulation of the immune system that prevented intravenous administration of viruses. This review provides insight into this intriguing new frontier on the delivery of oncolytic viruses to tumor sites.

TU-A-210-01: HIFU Physics and Delivery

High-intensity focused ultrasound (HIFU) has developed rapidly in recent years and is used frequently for clinical treatments in Asia and Europe with increasing clinical use and clinical trial activity in the US, making it an important medical technology with which the medical physics community must become familiar. Akin to medical devices that deliver treatments using ionizing radiation, HIFU relies on emitter geometry to non-invasively form a tight focus that can be used to affect diseased tissue while leaving healthy tissue intact. HIFU is unique in that it does not involve the use of ionizing radiation, it causes thermal necrosis in 100% of the treated tissue volume, and it has an immediate treatment effect. However, because it is an application of ultrasound energy, HIFU interacts strongly with tissue interfaces, which makes treatment planning challenging. In order to appreciate the advantages and disadvantages of HIFU as a thermal therapy, it is important to understand the underlying physics of ultrasound tissue interactions. The first lecture in the session will provide an overview of the physics of ultrasound wave propagation; the mechanism for the accumulation of heat in soft-tissue; image-guidance modalities including temperature monitoring; current clinical applications and commercial devices; active clinical trials; alternate mechanisms of action (future of FUS). The second part of the session will compare HIFU to existing ionization radiation techniques. The difficulties in defining a clear concept of absorbed dose for HIFU will be discussed. Some of the technical challenges that HIFU faces will be described, with an emphasis on how the experience of radiation oncology physicists could benefit the field. Learning Objectives: 1. Describe the basic physics and biology of HIFU, including treatment delivery and image guidance techniques. 2. Summarize existing and emerging clinical applications and manufacturers for HIFU. 3. Understand that thermal ablation with HIFU is likely the first of several applications of the technology 4. Learn about some similarities and differences between HIFU and ionizing radiation in terms of physics and biological effects. 5. Learn about some of the technical challenges HIFU faces that might benefit from the experience of radiation oncology physicists including treatment planning improvements, quality assurance procedures, and treatment risk analysis. David Schlesinger receives research support from Elekta Instruments, AB. Matt Eames is an employee of the Focused Ultrasound Foundation which supports research and clinical trials. Dr. Eames conducts research which is supported by the Focused Ultrasound Foundation.

TU-A-210-02: HIFU: Why Should a Radiation Oncology Physicist Pay Attention?

High-intensity focused ultrasound (HIFU) has developed rapidly in recent years and is used frequently for clinical treatments in Asia and Europe with increasing clinical use and clinical trial activity in the US, making it an important medical technology with which the medical physics community must become familiar. Akin to medical devices that deliver treatments using ionizing radiation, HIFU relies on emitter geometry to non-invasively form a tight focus that can be used to affect diseased tissue while leaving healthy tissue intact. HIFU is unique in that it does not involve the use of ionizing radiation, it causes thermal necrosis in 100% of the treated tissue volume, and it has an immediate treatment effect. However, because it is an application of ultrasound energy, HIFU interacts strongly with tissue interfaces, which makes treatment planning challenging. In order to appreciate the advantages and disadvantages of HIFU as a thermal therapy, it is important to understand the underlying physics of ultrasound tissue interactions. The first lecture in the session will provide an overview of the physics of ultrasound wave propagation; the mechanism for the accumulation of heat in soft-tissue; image-guidance modalities including temperature monitoring; current clinical applications and commercial devices; active clinical trials; alternate mechanisms of action (future of FUS). The second part of the session will compare HIFU to existing ionization radiation techniques. The difficulties in defining a clear concept of absorbed dose for HIFU will be discussed. Some of the technical challenges that HIFU faces will be described, with an emphasis on how the experience of radiation oncology physicists could benefit the field. Learning Objectives: 1. Describe the basic physics and biology of HIFU, including treatment delivery and image guidance techniques. 2. Summarize existing and emerging clinical applications and manufacturers for HIFU. 3. Understand that thermal ablation with HIFU is likely the first of several applications of the technology 4. Learn about some similarities and differences between HIFU and ionizing radiation in terms of physics and biological effects. 5. Learn about some of the technical challenges HIFU faces that might benefit from the experience of radiation oncology physicists including treatment planning improvements, quality assurance procedures, and treatment risk analysis. David Schlesinger receives research support from Elekta Instruments, AB. Matt Eames is an employee of the Focused Ultrasound Foundation which supports research and clinical trials. Dr. Eames conducts research which is supported by the Focused Ultrasound Foundation.

TU-A-210-00: HIFU Therapies - A Primer

High-intensity focused ultrasound (HIFU) has developed rapidly in recent years and is used frequently for clinical treatments in Asia and Europe with increasing clinical use and clinical trial activity in the US, making it an important medical technology with which the medical physics community must become familiar. Akin to medical devices that deliver treatments using ionizing radiation, HIFU relies on emitter geometry to non-invasively form a tight focus that can be used to affect diseased tissue while leaving healthy tissue intact. HIFU is unique in that it does not involve the use of ionizing radiation, it causes thermal necrosis in 100% of the treated tissue volume, and it has an immediate treatment effect. However, because it is an application of ultrasound energy, HIFU interacts strongly with tissue interfaces, which makes treatment planning challenging. In order to appreciate the advantages and disadvantages of HIFU as a thermal therapy, it is important to understand the underlying physics of ultrasound tissue interactions. The first lecture in the session will provide an overview of the physics of ultrasound wave propagation; the mechanism for the accumulation of heat in soft-tissue; image-guidance modalities including temperature monitoring; current clinical applications and commercial devices; active clinical trials; alternate mechanisms of action (future of FUS). The second part of the session will compare HIFU to existing ionization radiation techniques. The difficulties in defining a clear concept of absorbed dose for HIFU will be discussed. Some of the technical challenges that HIFU faces will be described, with an emphasis on how the experience of radiation oncology physicists could benefit the field. Learning Objectives: 1. Describe the basic physics and biology of HIFU, including treatment delivery and image guidance techniques. 2. Summarize existing and emerging clinical applications and manufacturers for HIFU. 3. Understand that thermal ablation with HIFU is likely the first of several applications of the technology 4. Learn about some similarities and differences between HIFU and ionizing radiation in terms of physics and biological effects. 5. Learn about some of the technical challenges HIFU faces that might benefit from the experience of radiation oncology physicists including treatment planning improvements, quality assurance procedures, and treatment risk analysis. David Schlesinger receives research support from Elekta Instruments, AB. Matt Eames is an employee of the Focused Ultrasound Foundation which supports research and clinical trials. Dr. Eames conducts research which is supported by the Focused Ultrasound Foundation.

Bronchial Thermoplasty by Application of Ultrasound Energy

Background: Asthma is a chronic inflammatory disease of respiratory airways, typically marked by spasms in the bronchi of the lungs, causing difficulty in breathing. Although the disease is very well documented, therapies are limited and patients mostly undergo symptom management. Bronchial thermoplasty is a radiofrequency-based treatment for severe asthma approved by Food and Drug Administration (FDA) in 2010 (Alair system, Boston Scientific Inc). Here we propose the use of ultrasound (US) energy to perform bronchial thermoplasty. Our hypothesis is that ultrasound affects bronchial smooth muscle at least as effective as radio-frequency (RF) but causes less collateral damage, and holds the potential to reduce the procedure time. In this publication we present a direct comparison of acute thermoplasty effects of RF energy versus ultrasound energy. Objective: To evaluate a bronchoscopic procedure based on circumferential ultrasound energy and its effect on bronchial wall structures in comparison to RF thermoplasty for asthma treatment. Methods: This is an observational study aiming for a direct comparison of an ultrasound system with existing asthma therapy based on radio-frequency. Mongrel dogs were used for optimization of ultrasound energy (300 J, 200 J, 100 J) with a 4.5 and 5.5 mm balloon catheter. 100 J was ultimately directly compared with RF effects on bronchial wall structures. Safety and efficacy of the ultrasound system was already previously established during renal denervation clinica stdies. Results: 12 mongrel dogs were used. Bronchoscopy procedures were feasible in all cases, and no adverse effects were seen in any dogs. Lungs were collected for histology and H&E staining. With the optimized 100 J ultrasound energy we observed mild bronchial tissue injury, with minimal hemorrhage and preservation of respiratory epithelium. The RF catheter caused distinct focal injury points resulting from direct contact of the RF electrodes with bronchial wall tissue. Acute histological examination shows hemorrhagic injury along the RF energy path with significant necrosis to all bronchial wall elements including respiratory epithelium. Conclusion: Ultrasound energy is safe, feasible, and at least as effective in affecting bronchoconstriction as RF energy offering a viable alternative to radiofrequency-based lung disease treatments.

Preparation of Biodiesel Using Ultrasonication Energy and its Performance in CI Engine

Fatty acid methyl ester (FAME), a renewable liquid biofuel popularly known as biodiesel, is emerging as a suitable replacement to common diesel fuel (CDF) in unmodified Compression Ignition (CI) engine. Present article reports the development of a process to reduce the operating cost during the conversion of vegetable oil to biodiesel through the application of ultrasound energy. Around 98% yield of FAME could be achieved with low reaction parameters such as methanol-oil molar ratio, catalyst concentration, reaction time, and temperature. The optimum condition for the maximum 98% yield was 1.0 wt% of NaOH catalyst, 5:1 methanol: oil molar ratio and temperature 55°C under a sonication frequency of 20 kHz. With these reaction parameters the conversion occurred in just 5 minutes. The FAME obtained was purified in an effective way by water washing followed by passing over a bed of silica gel. The purified FAME was subjected to the evaluation of its fuel characteristics in a four-stroke, single-cylinder CI engine, which could operate with variable compression ratio. The engine performance study revealed that lower blends of biodiesel up to B20 could be an efficient fuel for an unmodified CI engine.

Ondas ultra-sônicas de alta freqüência causam disfunção endotelial em artérias coronárias caninas epicárdicas

Application of ultrasound energy by an endarterectomy probe can facilitate the removal of atheromatous plaque, but the effect of this procedure on surrounding vessel structure and function is still a matter of experimental investigations. To determine whether ultrasound energy impairs the production of nitric oxide or damages vascular smooth muscle function, isolated canine epicardial coronary artery segments were exposed to either high (25 W) or low (0-10 W) ultrasonic energy outputs, for 15 seconds, using an endarterectomy device prototype. After exposure, segments of epicardial coronary artery were studied in organ chambers. The following drugs were used: adenosine diphosphate (ADP), acetylcholine (Ach) and sodium fluoride (NaF) to study endothelium-dependent relaxation and sodium nitroprusside (SNP) and isoproterenol to evaluate endothelium-independent relaxation. Application of high ultrasonic energy power impaired endothelium-dependent relaxation to ADP (10(-9)-10(-4) M), Ach (10(-9)-10(-4) M) and NaF (0.5-9.5 mM) in epicardial coronary arteries. However, low ultrasound energy output at the tip of the probe did not alter the endothelium-dependent relaxation (either maximal relaxation or EC50) to the same agonists. Vascular smooth muscle relaxation to isoproterenol (10(-9)-10(-5) M) or SNP (10(-9)-10(-6) M) was unaltered following exposure to either low or high ultrasonic energy outputs. These experiments currently prove that ultrasonic energy changes endothelial function of epicardial coronary arteries at high power. However, ultrasound does not alter the ability of vascular smooth muscle of canine epicardial coronary arteries to relax.