{"title":"Ultrasound-induced cell detachment and gene transfection in adherent cells","authors":"Xiaochun Lu, P. Zhong","doi":"10.1121/1.1909243","DOIUrl":"https://doi.org/10.1121/1.1909243","url":null,"abstract":"The effect of 1-MHz cw ultrasound (0.36 MPa in pressure amplitude) on cell detachment and gene transfection in adherent HeLa cells was investigated. Cell detachment, cell injury, and gene transfection (up to 50%) in surviving populations were found to increase progressively with exposure duration (0–20 s). However, with respect to the total exposed cells, gene transfection efficiency in the adherent cells (3%) was significantly lower than its counterpart without detachment (15%). Cell detachment by ultrasound exposure was accompanied by significantly reduced proliferation rate with greatly increased apoptosis in the surviving detached cell population.","PeriodicalId":87384,"journal":{"name":"Acoustics research letters online : ARLO","volume":"32 1","pages":"195-200"},"PeriodicalIF":0.0,"publicationDate":"2005-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86600514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Charles R. Thomas, C. Farny, C. Coussios, Ronald A. Roy, R. G. Holt
{"title":"Dynamics and control of cavitation during high-intensity focused ultrasound application","authors":"Charles R. Thomas, C. Farny, C. Coussios, Ronald A. Roy, R. G. Holt","doi":"10.1121/1.1901744","DOIUrl":"https://doi.org/10.1121/1.1901744","url":null,"abstract":"In this paper the results of two studies related to high-intensity focused ultrasound (HIFU) and cavitation are reported. The first study described used polyacrylamide phantoms to gain insight into the behavior of cavitation activity in the focal region of the HIFU transducer. Results indicate that cavitation is the source of a previously observed enhanced heating effect in HIFU. The second study discussed used agar-graphite phantoms to see if changing the duty cycle of the driving could effect some measure of control over the cavitation activity; the results indicate that it can.","PeriodicalId":87384,"journal":{"name":"Acoustics research letters online : ARLO","volume":"16 1","pages":"182-187"},"PeriodicalIF":0.0,"publicationDate":"2005-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74109823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Know thy sound field","authors":"S. Madanshetty, Jogesh B. Chandran","doi":"10.1121/1.1903023","DOIUrl":"https://doi.org/10.1121/1.1903023","url":null,"abstract":"Calibrated reference hydrophones like the Marconi bilaminar PVDF hydrophone are convenient in measuring pressures associated with high-intensity, low-megahertz acoustic fields used in microcavitation studies. These reference hydrophones are delicate and stand the risk of being easily ruined if cavitation occurs during their use. They are also expensive and not easily available. This article describes a method, based on radiation force balance, for characterizing an inexpensive, PZT-type needle probe which then can be used in lieu of the Marconi hydrophones. It is found that the method is accurate and precise and yields measurements in conformance with AIUM-NEMA standards.","PeriodicalId":87384,"journal":{"name":"Acoustics research letters online : ARLO","volume":"1 1","pages":"169-174"},"PeriodicalIF":0.0,"publicationDate":"2005-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80425713","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Low-frequency dispersion in bubbly liquids","authors":"P. Wilson","doi":"10.1121/1.1903024","DOIUrl":"https://doi.org/10.1121/1.1903024","url":null,"abstract":"The low-frequency sound speed in bubbly liquids is often modeled with an approximate equation [Wood, A Textbook of Sound, 1st ed. (MacMillan, New York, 1930)] that depends primarily on the void fraction. More recent models, developed for use at the individual bubble resonance frequency, predict a small amount of dispersion in Wood’s “dispersionless” regime. We present low-frequency data and compare it to a broadband model by Commander and Prosperetti [J. Acoust. Soc. Am. 85(2), 732–746 (1989)]. The purpose is to illustrate that dispersion of the order 5% is expected and occurs in Wood’s regime, and to point out a discrepancy between the Ruggles and the Commander and Prosperetti models regarding void fraction.","PeriodicalId":87384,"journal":{"name":"Acoustics research letters online : ARLO","volume":"119 1","pages":"188-194"},"PeriodicalIF":0.0,"publicationDate":"2005-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73566930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Response of an ultrasonically excited bubble near a fixed rigid object","authors":"Hongyu Miao, S. Gracewski","doi":"10.1121/1.1898344","DOIUrl":"https://doi.org/10.1121/1.1898344","url":null,"abstract":"Various independent studies suggest that echo-contrast agents can increase the likelihood of ultrasonic bioeffects. To better understand bioeffects involving cavitation, a two-dimensional boundary element model was used to simulate ultrasonically excited bubble behavior near a rigid object, either a plane, sphere, or disk, the approximate size of a red blood cell. As the distance between the object and bubble increases, the bubble collapse becomes more spherically symmetric, producing higher maximum bubble pressures. Pressure and velocity fields around a bubble collapsing near a rigid disk are compared for two distances, demonstrating differences between more spherically symmetric and asymmetric bubble collapses.","PeriodicalId":87384,"journal":{"name":"Acoustics research letters online : ARLO","volume":"9 1","pages":"144-150"},"PeriodicalIF":0.0,"publicationDate":"2005-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81214646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
E. Everbach, D. Khismatullin, J. Flaherty, Ronald A. Roy
{"title":"Characterization of individual submicron perfluorocarbon gas bubbles by ultrasonic backscatter","authors":"E. Everbach, D. Khismatullin, J. Flaherty, Ronald A. Roy","doi":"10.1121/1.1901743","DOIUrl":"https://doi.org/10.1121/1.1901743","url":null,"abstract":"Measurements were undertaken to determine the unknown microbubble-size distribution of a dodecafluoropentane (DDFP) emulsion consisting of 1012 droplets/ml in surfactant-stabilized water. The acoustic backscatter of 2-microsecond-duration tonebursts of 30-MHz focused ultrasound was measured from the emulsion as it moved in a coaxial flow. Calibration for the system was accomplished using 3-μm-radius polystyrene spheres, using a linear scattering model and literature values for polystyrene. Applying viscous linear scattering theory to the backscatter data from individual DDFP bubbles allowed inversion of the radius–backscatter relation. A mean microbubble radius of 130 nm was inferred for the DDFP population.","PeriodicalId":87384,"journal":{"name":"Acoustics research letters online : ARLO","volume":"1 1","pages":"175-181"},"PeriodicalIF":0.0,"publicationDate":"2005-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88813595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Compensatory responses to brief perturbations of speech amplitude","authors":"T. Heinks-Maldonado, J. Houde","doi":"10.1121/1.1931747","DOIUrl":"https://doi.org/10.1121/1.1931747","url":null,"abstract":"One of the key questions about speech production is the role that auditory feedback plays in the process. Here, it was investigated whether speakers show fast compensatory changes to brief perturbations of the loudness of their feedback. Speech from each subject was amplified and fed into an Eventide Ultraharmonizer that introduced brief (400 ms)±10-dB perturbations to volume of the subject’s audio feedback. Compensatory responses to both amplitude perturbation types were found in all subjects, which occurred at a similar latency (−10 dB: 171 ms; +10 dB: 287 ms) to that previously observed in responses to pitch perturbations.","PeriodicalId":87384,"journal":{"name":"Acoustics research letters online : ARLO","volume":"15 1","pages":"131-137"},"PeriodicalIF":0.0,"publicationDate":"2005-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84229395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Culjat, Rahul S. Singh, S. White, R. Neurgaonkar, E. Brown
{"title":"Evaluation of gallium-indium alloy as an acoustic couplant for high-impedance, high-frequency applications","authors":"M. Culjat, Rahul S. Singh, S. White, R. Neurgaonkar, E. Brown","doi":"10.1121/1.1903025","DOIUrl":"https://doi.org/10.1121/1.1903025","url":null,"abstract":"Materials are investigated for coupling ultrasound between solid piezoelectric transducers and solid targets having acoustic impedances ranging between 10–20 MRayl. The majority of available acoustic couplants have impedances below 5 MRayl, leading to large surface reflections and acoustic losses. The desired couplant is preferably liquid or semiliquid with good conformability and low attenuation. This study examines the acoustic properties of various couplants, including gallium–indium alloys. Transmission tests were conducted at 19 MHz, concluding that these alloys are most appropriate for the stated application, with low attenuation, high acoustic impedance (17.4 MRayl), and a measured compressional velocity of 2740 m/s.","PeriodicalId":87384,"journal":{"name":"Acoustics research letters online : ARLO","volume":"28 1","pages":"125-130"},"PeriodicalIF":0.0,"publicationDate":"2005-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76887323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Listener sensitivity to variations in the relative amplitude of vowel formants","authors":"E. Jacewicz","doi":"10.1121/1.1905384","DOIUrl":"https://doi.org/10.1121/1.1905384","url":null,"abstract":"Listener sensitivity to formant amplitude variations in the perception of both within- and between-vowel-category differences was examined for two isolated synthetic vowels, /i/ and /ɪ/. The relative amplitudes of F2 and F4 were varied in steps along acoustic continua which were created in accord with formant amplitude patterns found in natural speech. The results showed that vowel-specific patterns of formant amplitude variation affected listeners’ judgments of “naturalness” of each vowel token, as well as its phonetic quality.","PeriodicalId":87384,"journal":{"name":"Acoustics research letters online : ARLO","volume":"119 1","pages":"118-124"},"PeriodicalIF":0.0,"publicationDate":"2005-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77414736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Moderate auditory training can improve speech performance of adult cochlear implant patients","authors":"Q. Fu, J. Galvin, Xiaosong Wang, G. Nogaki","doi":"10.1121/1.1898345","DOIUrl":"https://doi.org/10.1121/1.1898345","url":null,"abstract":"Learning electrically stimulated speech patterns can be a new and difficult experience for many cochlear implant users. In the present study, ten cochlear implant patients participated in an auditory training program using speech stimuli. Training was conducted at home using a personal computer for 1 hour per day, 5 days per week, for a period of 1 month or longer. Results showed a significant improvement in all patients’ speech perception performance. These results suggest that moderate auditory training using a computer-based auditory rehabilitation tool can be an effective approach for improving the speech perception performance of cochlear implant patients.","PeriodicalId":87384,"journal":{"name":"Acoustics research letters online : ARLO","volume":"7 1","pages":"106-111"},"PeriodicalIF":0.0,"publicationDate":"2005-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78443604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}