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PubMed2006

Absorption kinetics of ozone in water with ultrasonic radiation.

A mathematical model was proposed to depict classical unsteady state method that was used to determine volumetric mass transfer coefficient of ozone from gaseous phase to aqueous phase during sonolysis. The rate constant of ozone self-decomposition with ultrasonic radiation, which was one of the parameters in the model, was determined with separate experiments. The results showed that self-decomposition rate constants of ozone were enhanced by ultrasound. The self-decomposition rate constant of ozone is linearly dependent on ultrasonic power, but the increase of the decomposition rate could not enhance ozone mass transfer coefficient. The volumetric mass transfer coefficients of ozone were also enhanced by ultrasonic radiation, while ultrasonic power had little effect on volumetric mass transfer coefficient of ozone. The degassing effect of ozone due to ultrasonic radiation was insignificant in the sparged system when ozone was bubbled during sonolysis.

Absorption↗
PubMed2005

Laparoscopic lymphadenectomy for gynecologic malignancies using ultrasonically activated shears: analysis of first 100 cases.

OBJECTIVE: To evaluate the feasibility, safety and utility of the ultrasonic shears for laparoscopic pelvic and para-aortic lymph node retrieval in the treatment of gynecologic cancers. METHODS: Data on laparoscopic lymphadenectomy performed for gynecologic malignancies using ultrasonic shears over a 5-year period were collected and analyzed prospectively. RESULTS: Laparoscopic lymphadenectomy using ultrasonic shears was performed on 100 patients with a median age of 58 (17-87) years. The types of malignancies included cervical (n = 29), endometrial (n = 48), ovarian (n = 15), fallopian tube (n = 2), malignant mixed mesodermal tumor (n = 2), vaginal (n = 2) and synchronous ovarian and endometrial cancers (n = 2). Sites of lymphadenectomy included pelvic (n = 49), para-aortic (n = 30) or both pelvic and para-aortic (n = 21). The median nodal yield was 22 (0-87). 66/100 were complete lymphadenectomies with a median nodal yield of 28 (2-71). The median length of hospital stay was 2 (1-13) days and the average blood loss was 148 (0-500) ml. Overall complication rate was 13%. There were 3 intra-operative complications, which were all managed laparoscopically. There were no unplanned conversions to laparotomy. There were 10 post-operative complications including port-site metastasis in a patient with positive nodes (n = 1), trocar-site hernia requiring a second laparoscopy (n = 1), deep leg vein thrombosis (n = 1), and a small bowel obstruction (n = 1). CONCLUSIONS: This is the largest series to date demonstrating the safety and efficacy of ultrasonic shears in laparoscopic lymphadenectomy for gynecologic malignancies. In addition to the potential for lowering the risk for tissue damage, ultrasonic shears offer multifunctionality which allows for a simpler technique with the use of fewer instruments.

Adolescent↗
PubMed2004

Skeletonization versus pedicle preparation of the radial artery with and without the ultrasonic scalpel.

BACKGROUND: The radial artery (RA) is increasingly used for myocardial revascularization because of its presumed advantageous long-term patency rates. The vessel can be harvested as a pedicle or skeletonized. The aim of this study was to compare the skeletonization technique with pedicle preparation using either an ultrasonic scalpel or scissors. METHODS: Forty consecutive patients with coronary artery disease undergoing complete arterial revascularization were included in the study. In 20 patients the RAs were prepared using scissors and clips (group 1: skeletonization; group 2: pedicle). In another 20 patients the arteries harvested were prepared using an ultrasonic scalpel (group 3: skeletonization; group 4: pedicle). The RA was treated with papaverine to prevent spasm of the vessel during and after harvesting. Tissue specimens of each RA were taken to analyze endothelial morphology by scanning electron microscopy. After implantation of the RA, graft perfusion was measured with a flow probe. RESULTS: Harvesting the RA as a skeletonized vessel took more time as compared with pedicle preparation (group 1 vs group 2: 37.1 +/- 3.5 minutes vs 24.4 +/- 3.9 minutes; p < 0.001 and group 3 vs group 4: 31.1 +/- 3.5 minutes vs 25.6 +/- 3.7 minutes; p < 0.01). The number of hemostatic titanium clips was similarly higher in group 1 as opposed to group 2 (58.7 +/- 7.1 vs 38.7 +/- 7.1; p < 0.01). However, there was no difference between groups 3 and 4 (p = 0.086). The length of the RA after skeletonization with scissors and clips was 20.8 +/- 1.5 cm in contrast with 19.1 +/- 0.9 cm (p < 0.01) after dissection as a pedicle. In the groups using the ultrasonic scalpel, there was no difference in graft length (p = 0.062). Mean blood flow through the graft after establishing the proximal anastomosis was similar among all groups (groups 1, 2, 3, and 4: 50 +/- 20.1 mL/min, 53.8 +/- 24.3 mL/min, 56.3 +/- 25.1 mL/min, and 51.8 +/- 23 mL/min, respectively). Scanning electron microscopy demonstrated endothelial damage in all patients in groups 1, 2, and 3 and in 7 patients of group 4. Most endothelial lesions were minor except in group 3 in which 1 of 5 endothelial lesions were severe. Statistically significant differences was found between groups 1 and 2, and 3 and 4 with respect to the degree of endothelial damage (p < 0.01). CONCLUSIONS: Skeletonization using scissors and clips is more time consuming and technically more difficult, but yield significantly longer grafts. Skeletonization with an ultrasonic scalpel did not result in additional length and was more frequently associated with severe endothelial damage. Pedicle preparation using scissors or an ultrasonic scalpel is much simpler and faster, and does not jeopardize endothelial integrity.

Humans↗
PubMed1999

Inhibition of nitric oxide synthase reduces ultrasonic vocalizations of rat pups.

The present study investigated the effects of drugs acting on the brain nitric oxide pathway on ultrasonic vocalizations, body temperature and locomotion in 7-8-day-old rat pups. Both a selective neuronal nitric oxide synthase (NOS) inhibitor (7-nitroindazole) and a non-selective NOS inhibitor (nitro-L-arginine-methyl ester, L-NAME) decreased the number of ultrasonic vocalizations in a dose-dependent manner. The non-selective NOS inhibitor, L-NAME, suppressed not only ultrasonic vocalizations but also locomotion. The inactive isomer of the NOS inhibitor, nitro-D-arginine-methyl ester (D-NAME), and the biological precursor of nitric oxide, L-arginine, had no effect on ultrasonic vocalizations or locomotion. These data indicate that drugs suppressing nitric oxide synthesis produced an anxiolytic effect in rat pups. However, only the selective NOS inhibitor, 7-nitroindazole, was 'anxioselective', i.e., reduced ultrasonic vocalizations without causing sedation. Increased synthesis of nitric oxide in the brain had no apparent behavioral effect in this model.

Animals↗
PubMed1997

Comparison of the ultrasonic scalpel to CO2 laser and electrosurgery in terms of tissue injury and adhesion formation in a rabbit model.

OBJECTIVE: To determine the relative effect of an ultrasonic scalpel on reproductive tissue compared with CO2 laser and electrosurgery. DESIGN: Prospective, randomized animal study. SETTING: University laboratory setting. ANIMALS: Sixteen New Zealand White rabbits. INTERVENTION(S): A steel scalpel, an ultrasonic scalpel, a CO2 laser, or electrosurgery were used to perform an ovarian wedge resection and to remove the distal uterine horn. A 3-cm longitudinal incision also was made in the uterine horn. MAIN OUTCOME MEASURE(S): The number of 1-second bursts of needle-tip electrosurgery required for hemostasis, the depth and degree of coagulation necrosis, degree of fibrin deposition, and postoperative adhesion formation. RESULT(S): The amount of electrosurgery needed to achieve hemostasis was less for any of the four power techniques than for the steel scalpel, with the exception of the ultrasonic scalpel at level 5 when used on the ovary. The depth (range: 0.30 to 0.38 mm) and the degree of coagulation necrosis was not different for any of the power techniques. The fibrin score was greatest for the ultrasonic scalpel at level 5 in both the ovarian tissue and the uterine tissue. There was no difference in adhesion scores for the power techniques and the steel scalpel. CONCLUSION(S): The ultrasonic scalpel at level 3 is not different from either CO2 laser or electrosurgery in terms of hemostatic properties, coagulation necrosis, or adhesion formation in the rabbit model.

Animals↗
PubMed2003

New technology for the design of advanced ultrasonic transducers for high-power applications.

A new high-frequency ultrasonic transducer for wire bonding has been conceived, designed, prototyped and tested. In the design phase an advanced approach was used and established. The method is based on the two basic principles of modularity and iteration. The transducer is decomposed to its elementary components. For each component an initial design is obtained with finite elements method (FEM) simulations. The simulated ultrasonic modules are then built and characterized experimentally through laser-interferometry measurements and electrical resonance spectra. The comparison of simulation results with experimental data allows the parameters of FEM models to be iteratively adjusted and optimized. The achieved FEM simulations exhibit a remarkably high-predictive potential and allow full control on the vibration behavior of the ultrasonic modules and of the whole transducer. The new transducer is fixed on the wire bonder with a flange whose special geometry was calculated by means of FEM simulations. This flange allows the converter to be attached on the wire bonder not only in longitudinal nodes but also in radial nodes of the ultrasonic field excited in the horn. This leads to a nearly complete decoupling of the transducer to the wire bonder, which has not been previously obtained. The new approach to mount ultrasonic transducers on a welding-device is of major importance not only for wire bonding but also for all high-power ultrasound applications and has been patented.

Computer Simulation↗
PubMed1995

Preliminary investigation of ultrasonic root end preparation.

Recently, an ultrasonic instrument intended for root end preparation during periapical surgery has become commercially available. This study evaluated root end preparations in 30 extracted human teeth, comparing those prepared with ultrasonic instrumentation to teeth prepared in a traditional manner with a microhandpiece and to teeth prepared using a combination of the microhandpiece and the ultrasonic instrument. Specimens were evaluated for size of preparation, preparation debridement, and time required for preparation. Preparations with the ultrasonic device were found to be significantly smaller than the other techniques evaluated. Traditional and combined techniques resulted in greater debridement under the conditions of the study, and only the combined technique demonstrated an increase in time required for preparation. Ultrasonic instrumentation may provide significant advantages in the treatment of deeply fluted roots when an isthmus is present by reducing the risk of root perforation.

Dental Pulp Cavity↗
PubMed1996

Evaluation of cracks associated with ultrasonic root-end preparation.

The purpose of this study was to evaluate the integrity of resected root-end surfaces of extracted human teeth after using ultrasonic tips at low or high frequencies for root-end preparation. Thirty bilaterally matched pairs of single-rooted human teeth had root-end resections using a low-speed diamond saw and were examined for root-end cracks. The matched pairs of teeth were then divided into two experimental groups, with one member of each pair being placed in each group. In group 1, root-end preparations were made with an ultrasonic tip on the lowest frequency setting. The preparations in group 2 were done on the highest power setting. Two investigators again examined the resected root-ends using a stereomicroscope at x20 to x63 and recorded the numbers, types, and location of the cracks. Three types of cracks were observed: canal cracks, intradentin cracks, and cemental cracks. There were significantly more root-ends with cracks after ultrasonic root-end preparation than after root-end resection only. In root-ends that had any cracks, significantly more canal cracks per root occurred when the ultrasonic tip was used on the high-frequency setting for root-end preparation than when the ultrasonic tip was used on the low power setting.

Apicoectomy↗
PubMed2003

Ultrasonically induced cell damage and active oxygen generation by 4-formyloximeetylidene-3-hydroxyl-2-vinyl-deuterio-porphynyl(IX)-6-7-diaspartic acid: on the mechanism of sonodynamic activation.

Ultrasonically induced cell damage and active oxygen generation with 4-formyloximeetylidene-3-hydroxyl-2-vinyl-deuterio-porphynyl(IX)-6-7-diaspartic acid (ATX-S10) were compared in the same in vitro insonation setup. Sarcoma 180 cells suspended in air-saturated PBS were exposed to ultrasound at 2 MHz for up to 60 s in the presence and absence of ATX-S10. The viability was determined by Trypan blue exclusion test. Ultrasonically induced active oxygen generation in the presence and absence of ATX-S10 in air-saturated aqueous solutions of 50 mM 2,2,6,6-tetramethyl-4-piperidone was detected by electron spin resonance (ESR). Significant enhancement of the rates of both ultrasonically induced cell damage and nitroxide generation was demonstrated with 40-160 microM ATX-S10. Both rates correlated very well. The enhancement of both rates with ATX-S10 was suppressed by 10 mM histidine. These results suggest that ultrasonically generated active oxygen plays a primary role in the ultrasonically induced cell damage in the presence of ATX-S10.

Animals↗
PubMed1995

Minimal femoral cortical thickness necessary to prevent perforation by ultrasonic tools in joint revision surgery.

Ultrasonic tools are effective in removing cement in revision surgery and almost eliminate perforation of the femoral shaft, a dangerous complication associated with cement removal using drills, chisels, osteotomes, and other tools. Clinically, the ultrasonic tool used to remove cement could not be passed through a relatively normal femoral cortex; however, a perforation occurred in a patient with a femoral cortex less than 1 mm thick. The purpose of this study was to determine how thin the femoral cortex can be and yet allow the safe use of ultrasonic tools to remove cement without the risk of perforation. A cement mantle was constructed in the intramedullary canal of human cadaver femurs. Each specimen was mounted on a jig, which was then fastened to a Materials Testing System (Minneapolis, MN). The average load generated across the cortex by the ultrasonic tools while removing cement was measured. Loads of varying magnitudes were then applied by the ultrasonic tools to femoral cortices of varying thickness. When the cortex measured 3 mm thick, perforation did not occur. When the cortex measured 2 mm, perforation was possible but required loads three to six times greater than those normally used to remove cement.

Bone Cements↗
PubMed2002

Ultrasonic assessment of oil quality during frying.

In this paper, changes in ultrasonic properties during thermoxidation of virgin olive oil were studied. Samples of virgin olive oil were heated over different periods of time from 2 to 16 h at 200 degrees C. Oil degradation was characterized by means of physical and chemical changes, i.e., viscosity, color, polar compounds, polymers, and polar fatty acids. Ultrasonic measurements were carried out while the oil sample was cooled from 35 to 25 degrees C. It was found that velocity and attenuation measurements were related to viscosity measurements through a classical equation for viscous liquids. The ultrasonic measurements were also related to the percentages of polar compounds and polymers, which shows the feasibility of using ultrasonic properties to monitor oil quality. Nevertheless, as long as the ultrasonic measurements are temperature dependent, this variable must be controlled in order to obtain repetitive and reliable measurements.

Chemical Phenomena↗
PubMed2006

Ultrasonic degradation of polysaccharide from a red algae (Porphyra yezoensis).

Polysaccharide from Porphyra yezoensis (PYPS) was degraded by ultrasound in this study. The changes of intrinsic viscosity with various conditions, such as ultrasonic power, irradiation time, reaction temperature, initial pH value of solution, and its concentration, were investigated by using Ubbleholde viscometry. It was found that the ultrasonic degradation rate of PYPS solution increases with the increase of ultrasonic power and reaction temperature and the decrease of the initial pH value of the solution. The order of the susceptibility of initial PYPS concentrations on degradation is 0.75 > 0.5 > 1.00 > 2.00 g/dL. The mechanism about the ultrasonic degradation of PYPS may be explained by more for mechanical and less for radical effects. Relationships between degradation rate and ultrasound time are exponential functions. The activation energy of ultrasonic degradation of PYPS solution is 52.13 kJ/mol, which was calculated by the logarithmic form of the Arrhenius equation, and is lower than one for the acid or enzyme catalyzing degradation of similar glycosidic bonds.

Hydrogen-Ion Concentration↗
PubMed2006

Analysis of the phase diagram and microstructural transitions in phospholipid microemulsion systems using high-resolution ultrasonic spectroscopy.

In the present work, high-resolution ultrasonic spectroscopy was applied to analyze a pseudoternary phase diagram for mixtures consisting of water/isopropyl myristate/Epikuron 200 and a cosurfactant (n-propanol). Changes in the ultrasonic velocity and attenuation in the megahertz frequency range were measured in the course of titration of the oil/surfactant/cosurfactant mixture with water at 25 degrees C. The ultrasonic titration profiles showed several phase transitions in the samples, which allowed the construction of an "ultrasonic" phase diagram. Quantitative analysis of the ultrasonic parameters enabled the characterization of various phases (swollen micelles, microemulsion, coarse emulsion, and pseudo-bicontinuous) as well as the evaluation of the state of the water and the particle size. The particle size obtained for the microemulsion region ranged from 5 to 14 nm over the measured concentrations of water/isopropyl myristate/Epikuron 200 and n-propanol, which agreed well with the previous literature data.

1-Propanol↗
PubMed1995

Nebulization of fluids of different physicochemical properties with air-jet and ultrasonic nebulizers.

PURPOSE: Empirical formulae relate the mean size of primary droplets from jet and ultrasonic nebulizers to a fluid's physicochemical properties. Although the size selective "filtering" effects of baffling and evaporation may modify the secondary aerosol produced, this research sought to evaluate whether viscosity and surface tension of nebulized fluids influenced the aerosol's size and output characteristics. METHODS: Fluid systems of different surface tension and viscosity (glycerol and propylene glycol solutions [10-50% (v/v)] and a range of silicone fluids [200/0.65 cs-100cs]) were nebulized in three jet and two ultrasonic nebulizers. Secondary aerosol characteristics were measured with a Malvern 2600C laser diffraction sizer and the nebulization times, residual volumes and percentage outputs were determined. RESULTS: While the droplet size appeared to be inversely proportional to viscosity for jet nebulizers, it was directly proportional to viscosity for ultrasonic nebulizers. Although fluid systems with lower surface tensions generally produced slightly smaller MMDs, the relationship between surface tension and droplet size was complex. The more viscous fluids required longer nebulization times and were associated with increased residual amounts (lower outputs). The ultrasonic nebulizers did not effectively, and were on occasion unable to, nebulize the more viscous fluids. CONCLUSIONS: It follows that there are cut-off values for viscosity and/or surface tension above or below which ultrasonic devices fail to operate. Moreover, jet nebulizers generated an aerosol with an optimum respirable output from median-viscosity fluids.

Aerosols↗
PubMed1984

Electrophysiological and ultrasonic correlates of reproductive behavior in the male rat.

The purpose of the present study was to examine the electrophysiological correlates of copulatory behavior in the rat and correlate brain electroencephalographic (EEG) activity with the ultrasonic vocalizations that have been shown to play a major role in the integration of mating behavior. Ultrasonic vocalizations of male rats with chronically implanted hippocampal and cortical electrodes were monitored during mating with a female rat. Hippocampal theta rhythms were significantly correlated with high activity, mounting, intromissions, and preejaculatory excitatory behavior and were also significantly associated with 50-kHz short ultrasonic vocalizations. Postmount or postintromission behaviors (grooming, exploration) were closely correlated with an absence of ultrasonic vocalizations and the onset of irregular low-amplitude hippocampal EEG recordings. Long 22-kHz vocalizations occurred in all tests during the postejaculatory refractory period. Shorter 22-kHz vocalizations occurred during mating and were associated with unsuccessful intromissions or mounting attempts. Postejaculatory long 22-kHz vocalizations were significantly associated with irregular high-amplitude hippocampal EEG tracings, and preejaculatory short 22-kHz vocalizations were also accompanied by sleep-like irregular high-amplitude hippocampal EEG tracings with cortical spindling. The correlation of ultrasonic vocalizations with electroencephalographic and behavioral manifestations of central arousal and inhibitory processes suggests that these vocalizations are indicators of the sexual arousal of the mating pair.

Animals↗
PubMed1998

Bacterial eradication from root dentine by ultrasonic irrigation with sodium hypochlorite.

The study aimed to evaluate intracanal irrigation procedures in eradicating bacteria from surface, shallow and deep layers of root dentine using extracted human teeth. Artificial bacterial smear layer was successfully produced by rubbing a mixture of dental plaque and artificially decalcified dentine or carious dentine on root canal walls. The reservoir holes were 3.5 mm in depth, 1 mm in diameter prepared 1.5 mm apart and parallel to the root canals on the decrowned planes, in which five separate bacterial species were placed (Actinomyces israelii, Fusobacterium nucleatum, Propionibacterium acnes, Streptococcus mutans and Streptococcus sanguis). Bacterial eradication after irrigation of the prepared canals was determined by bacterial recovery (i) from the root canal surfaces and shallow layers where bacteria were smeared artificially and (ii) from deeper layers of root canal dentine reservoir holes. Ultrasonic irrigation with 5.5% and 12% NaOCl eradicated bacteria from artificial smear layer (P < 0.0001), whilst 12% NaOCl irrigation with a syringe was insufficient. Ultrasonic irrigation with water or 15% EDTA-failed to eradicate bacteria from smeared surfaces. Ultrasonic irrigation with 12% NaOCl killed A. israelii, F. nucleatum, P. acnes, S. mutans, and S. sanguis placed in reservoir channels, although for F. nucleatum, a very small number of bacteria remained in five samples out of 12. Ultrasonic irrigation with less concentrated NaOCl failed to eliminate bacteria completely from reservoir channels in most samples. Ultrasonic irrigation with 12% NaOCl appeared to eliminate bacteria efficiently from surface, shallow and deep layers of root dentine.

Actinomyces↗
PubMed2002

Effects of rotary instruments and ultrasonic irrigation on debris and smear layer scores: a scanning electron microscopic study.

AIM: This study evaluated debris and smear layer scores after two types of instruments manufactured from different alloys were used to ultrasonically activate irrigants during canal preparation. The influence of two rotary preparation techniques on cleanliness of the shaped canals was also studied. METHODOLOGY: Apical stops were prepared to size 45 in 42 single-canalled extracted premolars and canines, which were divided into six equal groups. Groups 1, 2 and 3 were prepared by ProFile.04 (PF) while groups 4, 5 and 6 were prepared by Lightspeed (LS). All groups were irrigated using 5.25% NaOCl and 17% EDTA. Irrigants in groups 2 and 5 were ultrasonically activated using a size 15 steel K-file and by a blunt flexible nickel-titanium wire in groups 3 and 6. Groups 1 and 4 served as negative controls. Roots were split and canal walls examined at 15x, 200x and 400x magnification in an SEM. Smear layer and debris scores were recorded at 3, 6 and 9 mm levels using a 5-step scoring scale and a 200- micro m grid. Means were tested for significance using nonparametric Mann-Whitney U and Kruskal-Wallis tests. RESULTS: Debris and smear layer scores for the six groups varied from 1.98 +/- 1.04 to 3.47 +/- 0.97 and from 1.37 +/- 0.4 to 2.36 +/- 0.99, respectively. Although all groups had significantly higher smear layer and debris scores at the 3 mm levels compared to the 9 mm levels (P < 0.05), no significant differences were recorded due to the ultrasonic energy transmitted by the two alloys. CONCLUSION: Ultrasonically activated irrigants did not reduce debris or smear layer scores. This finding was not influenced by the material nor by the design of the instrument used to transmit ultrasonic activation.

Dental Instruments↗
PubMed2005

Interface evaluation after manual and ultrasonic insertion of standardized class I inlays using composite resin materials of different viscosity.

OBJECTIVE: The aim of the present study was to investigate the effect of manual and ultrasonic insertion of standardized class I inlays (Cerana) using three composite resin materials of different viscosity (Tetric Flow, Tetric, and Tetric Ceram) on time to seat inlays, film thickness, and filler distribution within the materials. METHODS: In a preliminary test, mean loads for manual and ultrasonic insertion were measured using the high viscosity composite resin material (Tetric Ceram). These loads were then applied with all composite resin materials to evaluate the times required to seat the inlays. In addition, film thickness was assessed using scanning electron microscopy, and filler distribution (wt% silicon, barium, ytterbium) was monitored using energy-dispersive spectroscopy. RESULTS: Ultrasonic insertion significantly reduced mean load applied to seat inlays (6.4+/-1.4 N; mean+/-SD) as compared to manual insertion (18.9+/-3.1 N; p < 0.001). Using an ultrasonic device, times for insertion values were significantly lower in the high and medium viscosity composite resin material groups compared to manual insertion (p < 0.05). The widest film thickness was recorded for the high viscosity composite resin material in combination with manual insertion (p < 0.05). However, when ultrasound was applied, there was no difference in film thickness between the three materials at any levels. Furthermore, the analysis of filler distribution revealed no significant differences between groups. CONCLUSION: Highly filled viscous composite resin materials may be used in combination with the ultrasonic insertion technique without untoward effects on film thickness or filler distribution.

Barium↗