WorldWideScience

Sample records for hemispherical ultrasound phased

  1. A 1372-element Large Scale Hemispherical Ultrasound Phased Array Transducer for Noninvasive Transcranial Therapy

    International Nuclear Information System (INIS)

    Song, Junho; Hynynen, Kullervo

    2009-01-01

    Noninvasive transcranial therapy using high intensity focused ultrasound transducers has attracted high interest as a promising new modality for the treatments of brain related diseases. We describe the development of a 1372 element large scale hemispherical ultrasound phased array transducer operating at a resonant frequency of 306 kHz. The hemispherical array has a diameter of 31 cm and a 15.5 cm radius of curvature. It is constructed with piezoelectric (PZT-4) tube elements of a 10 mm in diameter, 6 mm in length and 1.4 mm wall thickness. Each element is quasi-air backed by attaching a cork-rubber membrane on the back of the element. The acoustic efficiency of the element is determined to be approximately 50%. The large number of the elements delivers high power ultrasound and offers better beam steering and focusing capability. Comparisons of sound pressure-squared field measurements with theoretical calculations in water show that the array provides good beam steering and tight focusing capability over an efficient volume of approximately 100x100x80 mm 3 with nominal focal spot size of approximately 2.3 mm in diameter at -6 dB. We also present its beam steering and focusing capability through an ex vivo human skull by measuring pressure-squared amplitude after phase corrections. These measurements show the same efficient volume range and focal spot sizes at -6 dB as the ones in water without the skull present. These results indicate that the array is sufficient for use in noninvasive transcranial ultrasound therapy.

  2. A multi-frequency sparse hemispherical ultrasound phased array for microbubble-mediated transcranial therapy and simultaneous cavitation mapping.

    Science.gov (United States)

    Deng, Lulu; O'Reilly, Meaghan A; Jones, Ryan M; An, Ran; Hynynen, Kullervo

    2016-12-21

    Focused ultrasound (FUS) phased arrays show promise for non-invasive brain therapy. However, the majority of them are limited to a single transmit/receive frequency and therefore lack the versatility to expose and monitor the treatment volume. Multi-frequency arrays could offer variable transmit focal sizes under a fixed aperture, and detect different spectral content on receive for imaging purposes. Here, a three-frequency (306, 612, and 1224 kHz) sparse hemispherical ultrasound phased array (31.8 cm aperture; 128 transducer modules) was constructed and evaluated for microbubble-mediated transcranial therapy and simultaneous cavitation mapping. The array is able to perform effective electronic beam steering over a volume spanning (-40, 40) and (-30, 50) mm in the lateral and axial directions, respectively. The focal size at the geometric center is approximately 0.9 (2.1) mm, 1.7 (3.9) mm, and 3.1 (6.5) mm in lateral (axial) pressure full width at half maximum (FWHM) at 1224, 612, and 306 kHz, respectively. The array was also found capable of dual-frequency excitation and simultaneous multi-foci sonication, which enables the future exploration of more complex exposure strategies. Passive acoustic mapping of dilute microbubble clouds demonstrated that the point spread function of the receive array has a lateral (axial) intensity FWHM between 0.8-3.5 mm (1.7-11.7 mm) over a volume spanning (-25, 25) mm in both the lateral and axial directions, depending on the transmit/receive frequency combination and the imaging location. The device enabled both half and second harmonic imaging through the intact skull, which may be useful for improving the contrast-to-tissue ratio or imaging resolution, respectively. Preliminary in vivo experiments demonstrated the system's ability to induce blood-brain barrier opening and simultaneously spatially map microbubble cavitation activity in a rat model. This work presents a tool to investigate optimal strategies for non

  3. Registration of human skull computed tomography data to an ultrasound treatment space using a sparse high frequency ultrasound hemispherical array

    Energy Technology Data Exchange (ETDEWEB)

    O’Reilly, Meaghan A., E-mail: moreilly@sri.utoronto.ca; Jones, Ryan M. [Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario M4N 3M5 (Canada); Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 1L7 (Canada); Birman, Gabriel [Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario M4N 3M5 (Canada); Hynynen, Kullervo [Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario M4N 3M5 (Canada); Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 1L7 (Canada); Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9 (Canada)

    2016-09-15

    Purpose: Transcranial focused ultrasound (FUS) shows great promise for a range of therapeutic applications in the brain. Current clinical investigations rely on the use of magnetic resonance imaging (MRI) to monitor treatments and for the registration of preoperative computed tomography (CT)-data to the MR images at the time of treatment to correct the sound aberrations caused by the skull. For some applications, MRI is not an appropriate choice for therapy monitoring and its cost may limit the accessibility of these treatments. An alternative approach, using high frequency ultrasound measurements to localize the skull surface and register CT data to the ultrasound treatment space, for the purposes of skull-related phase aberration correction and treatment targeting, has been developed. Methods: A prototype high frequency, hemispherical sparse array was fabricated. Pulse-echo measurements of the surface of five ex vivo human skulls were made, and the CT datasets of each skull were obtained. The acoustic data were used to rigidly register the CT-derived skull surface to the treatment space. The ultrasound-based registrations of the CT datasets were compared to the gold-standard landmark-based registrations. Results: The results show on an average sub-millimeter (0.9 ± 0.2 mm) displacement and subdegree (0.8° ± 0.4°) rotation registration errors. Numerical simulations predict that registration errors on this scale will result in a mean targeting error of 1.0 ± 0.2 mm and reduction in focal pressure of 1.0% ± 0.6% when targeting a midbrain structure (e.g., hippocampus) using a commercially available low-frequency brain prototype device (InSightec, 230 kHz brain system). Conclusions: If combined with ultrasound-based treatment monitoring techniques, this registration method could allow for the development of a low-cost transcranial FUS treatment platform to make this technology more widely available.

  4. Registration of human skull computed tomography data to an ultrasound treatment space using a sparse high frequency ultrasound hemispherical array.

    Science.gov (United States)

    O'Reilly, Meaghan A; Jones, Ryan M; Birman, Gabriel; Hynynen, Kullervo

    2016-09-01

    Transcranial focused ultrasound (FUS) shows great promise for a range of therapeutic applications in the brain. Current clinical investigations rely on the use of magnetic resonance imaging (MRI) to monitor treatments and for the registration of preoperative computed tomography (CT)-data to the MR images at the time of treatment to correct the sound aberrations caused by the skull. For some applications, MRI is not an appropriate choice for therapy monitoring and its cost may limit the accessibility of these treatments. An alternative approach, using high frequency ultrasound measurements to localize the skull surface and register CT data to the ultrasound treatment space, for the purposes of skull-related phase aberration correction and treatment targeting, has been developed. A prototype high frequency, hemispherical sparse array was fabricated. Pulse-echo measurements of the surface of five ex vivo human skulls were made, and the CT datasets of each skull were obtained. The acoustic data were used to rigidly register the CT-derived skull surface to the treatment space. The ultrasound-based registrations of the CT datasets were compared to the gold-standard landmark-based registrations. The results show on an average sub-millimeter (0.9 ± 0.2 mm) displacement and subdegree (0.8° ± 0.4°) rotation registration errors. Numerical simulations predict that registration errors on this scale will result in a mean targeting error of 1.0 ± 0.2 mm and reduction in focal pressure of 1.0% ± 0.6% when targeting a midbrain structure (e.g., hippocampus) using a commercially available low-frequency brain prototype device (InSightec, 230 kHz brain system). If combined with ultrasound-based treatment monitoring techniques, this registration method could allow for the development of a low-cost transcranial FUS treatment platform to make this technology more widely available.

  5. PHASE RELATIONSHIPS OF SOLAR HEMISPHERIC TOROIDAL AND POLOIDAL CYCLES

    Energy Technology Data Exchange (ETDEWEB)

    Muraközy, J., E-mail: murakozy.judit@csfk.mta.hu [Debrecen Heliophysical Observatory (DHO), Konkoly Observatory, Research Centre for Astronomy and Earth Sciences H-4010 Debrecen P.O.B. 30, H-4010 (Hungary)

    2016-08-01

    The solar northern and southern hemispheres exhibit differences in their intensities and time profiles of the activity cycles. The time variation of these properties was studied in a previous article covering the data from Cycles 12–23. The hemispheric phase lags exhibited a characteristic variation: the leading role was exchanged between hemispheres every four cycles. The present work extends the investigation of this variation using the data of Staudacher and Schwabe in Cycles 1–4 and 7–10 as well as Spörer’s data in Cycle 11. The previously observed variation cannot be clearly recognized using the data of Staudacher, Schwabe, and Spörer. However, it is more interesting that the phase lags of the reversals of the magnetic fields at the poles follow the same variations as those of the hemispheric cycles in Cycles 12–23, i.e., one of the hemispheres leads in four cyles and the leading role jumps to the opposite hemisphere in the next four cycles. This means that this variation is a long-term property of the entire solar dynamo mechanism, for both the toroidal and poloidal fields, which hints at an unidentified component of the process responsible for the long-term memory.

  6. Intracavitary ultrasound phased arrays for thermal therapies

    Science.gov (United States)

    Hutchinson, Erin

    Currently, the success of hyperthermia and thermal surgery treatments is limited by the technology used in the design and fabrication of clinical heating devices and the completeness of the thermometry systems used for guidance. For both hyperthermia and thermal surgery, electrically focused ultrasound generated by phased arrays provides a means of controlling localized energy deposition in body tissues. Intracavitary applicators can be used to bring the energy source close to a target volume, such as the prostate, thereby minimizing normal tissue damage. The work performed in this study was aimed at improving noninvasive prostate thermal therapies and utilized three research approaches: (1) Acoustic, thermal and optimization simulations, (2) Design and fabrication of multiple phased arrays, (3) Ex vivo and in vivo experimental testing of the heating capabilities of the phased arrays. As part of this study, a novel aperiodic phased array design was developed which resulted in a 30- 45% reduction in grating lobe levels when compared to conventional phased arrays. Measured acoustic fields generated by the constructed aperiodic arrays agreed closely with the fields predicted by the theoretical simulations and covered anatomically appropriate ranges. The power capabilities of these arrays were demonstrated to be sufficient for the purposes of hyperthermia and thermal surgery. The advantage of using phased arrays in place of fixed focus transducers was shown by demonstrating the ability of electronic scanning to increase the size of the necrosed tissue volume while providing a more uniform thermal dose, which can ultimately reduce patient treatment times. A theoretical study on the feasibility of MRI (magnetic resonance imaging) thermometry for noninvasive temperature feedback control was investigated as a means to improve transient and steady state temperature distributions achieved in hyperthermia treatments. MRI guided ex vivo and in vivo experiments demonstrated

  7. Phase-space topography characterization of nonlinear ultrasound waveforms.

    Science.gov (United States)

    Dehghan-Niri, Ehsan; Al-Beer, Helem

    2018-03-01

    Fundamental understanding of ultrasound interaction with material discontinuities having closed interfaces has many engineering applications such as nondestructive evaluation of defects like kissing bonds and cracks in critical structural and mechanical components. In this paper, to analyze the acoustic field nonlinearities due to defects with closed interfaces, the use of a common technique in nonlinear physics, based on a phase-space topography construction of ultrasound waveform, is proposed. The central idea is to complement the "time" and "frequency" domain analyses with the "phase-space" domain analysis of nonlinear ultrasound waveforms. A nonlinear time series method known as pseudo phase-space topography construction is used to construct equivalent phase-space portrait of measured ultrasound waveforms. Several nonlinear models are considered to numerically simulate nonlinear ultrasound waveforms. The phase-space response of the simulated waveforms is shown to provide different topographic information, while the frequency domain shows similar spectral behavior. Thus, model classification can be substantially enhanced in the phase-space domain. Experimental results on high strength aluminum samples show that the phase-space transformation provides a unique detection and classification capabilities. The Poincaré map of the phase-space domain is also used to better understand the nonlinear behavior of ultrasound waveforms. It is shown that the analysis of ultrasound nonlinearities is more convenient and informative in the phase-space domain than in the frequency domain. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Proceedings of the Third EPRI Phased Array Ultrasound Seminar

    International Nuclear Information System (INIS)

    2003-01-01

    Phased array technology for ultrasonic examination is providing innovative solutions for nuclear in-service examination applications. EPRI has been a prime mover in the development and deployment of phased array ultrasound applications in the domestic nuclear market over the past decade. As part of this strategic effort, EPRI has hosted a series of seminars on phased array technology and its applications

  9. Hand movements with a phase structure and gestures that depict action stem from a left hemispheric system of conceptualization.

    Science.gov (United States)

    Helmich, I; Lausberg, H

    2014-10-01

    The present study addresses the previously discussed controversy on the contribution of the right and left cerebral hemispheres to the production and conceptualization of spontaneous hand movements and gestures. Although it has been shown that each hemisphere contains the ability to produce hand movements, results of left hemispherically lateralized motor functions challenge the view of a contralateral hand movement production system. To examine hemispheric specialization in hand movement and gesture production, ten right-handed participants were tachistoscopically presented pictures of everyday life actions. The participants were asked to demonstrate with their hands, but without speaking what they had seen on the drawing. Two independent blind raters evaluated the videotaped hand movements and gestures employing the Neuropsychological Gesture Coding System. The results showed that the overall frequency of right- and left-hand movements is equal independent of stimulus lateralization. When hand movements were analyzed considering their Structure, the presentation of the action stimuli to the left hemisphere resulted in more hand movements with a phase structure than the presentation to the right hemisphere. Furthermore, the presentation to the left hemisphere resulted in more right and left-hand movements with a phase structure, whereas the presentation to the right hemisphere only increased contralateral left-hand movements with a phase structure as compared to hand movements without a phase structure. Gestures that depict action were primarily displayed in response to stimuli presented in the right visual field than in the left one. The present study shows that both hemispheres possess the faculty to produce hand movements in response to action stimuli. However, the left hemisphere dominates the production of hand movements with a phase structure and gestures that depict action. We therefore conclude that hand movements with a phase structure and gestures that

  10. Phased array ultrasound testing on complex geometry

    International Nuclear Information System (INIS)

    Tuan Arif Tuan Mat; Khazali Mohd Zin

    2009-01-01

    Phase array ultrasonic inspection is used to investigate its response to complex welded joints geometry. A 5 MHz probe with 64 linear array elements was employed to scan mild steel T-joint, nozzle and node samples. These samples contain many defects such as cracks, lack of penetration and lack of fusion. Ultrasonic respond is analysed and viewed using the Tomoview software. The results show the actual phase array images on respective types of defect. (author)

  11. Hemispheric Lateralization of Event-Related Brain Potentials in Different Processing Phases during Unimanual Finger Movements

    Directory of Open Access Journals (Sweden)

    Yi-Wen Li

    2008-04-01

    Full Text Available Previous functional MRI and brain electrophysiology studies have studied the left-right differences during the tapping tasks and found that the activation of left hemisphere was more significant than that of right hemisphere. In this study, we wanted to delineate this lateralization phenomenon not only in the execution phase but also in other processing phases, such as early visual, pre-executive and post-executive phases. We have designed a finger-tapping task to delineate the left-right differences of event related potentials (ERPs to right finger movement in sixteen right handed college students. The mean amplitudes of ERPs were analyzed to examine the left-right dominance of cortical activity in the phase of early visual process (75-120ms, pre-execution (175-260ms, execution (310-420ms and post-execution (420-620ms. In the execution phase, ERPs at the left electrodes were significantly more pronounced than those at the right electrodes (F3 > F4, C3 > C4, P3 > P4, O1 > O2 under the situation without comparing the central electrodes (Fz, Cz, Pz, and Oz. No difference was found between left and right electrodes in other three phases except the C3 electrode still showed more dominant than C4 in the pre- and post-execution phase. In conclusion, the phenomenon of brain lateralization occur major in the execution phase. The central area also showed the lateralization in the pre- and post-execution to demonstrate its unique lateralized contributions to unilateral simple finger movements.

  12. SIMULATION STUDY OF HEMISPHERIC PHASE-ASYMMETRY IN THE SOLAR CYCLE

    Energy Technology Data Exchange (ETDEWEB)

    Shukuya, D.; Kusano, K., E-mail: kusano@nagoya-u.jp [Institute for Space-Earth Environmental Research, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 4648601 (Japan)

    2017-01-20

    Observations of the Sun suggest that solar activities systematically create north–south hemispheric asymmetries. For instance, the hemisphere in which sunspot activity is more active tends to switch after the early half of each solar cycle. Svalgaard and Kamide recently pointed out that the time gaps of polar field reversal between the northern and southern hemispheres are simply consequences of the asymmetry of sunspot activity. However, the mechanism underlying the asymmetric feature in solar cycle activity is not yet well understood. In this paper, in order to explain the cause of the asymmetry from the theoretical point of view, we investigate the relationship between the dipole- and quadrupole-type components of the magnetic field in the solar cycle using the mean-field theory based on the flux transport dynamo model. As a result, we found that there are two different attractors of the solar cycle, in which either the north or the south polar field is first reversed, and that the flux transport dynamo model explains well the phase-asymmetry of sunspot activity and the polar field reversal without any ad hoc source of asymmetry.

  13. Ultrasound cylindrical phased array for transoesophageal thermal therapy: initial studies

    International Nuclear Information System (INIS)

    Melodelima, David; Lafon, Cyril; Prat, Frederic; Birer, Alain; Cathignol, Dominique

    2002-01-01

    This work was undertaken to investigate the feasibility of constructing a cylindrical phased array composed of 64 elements spread around the periphery (OD 10.6 mm) for transoesophageal ultrasound thermotherapy. The underlying operating principle of this applicator is to rotate a plane ultrasound beam electronically. For this purpose, eight adjacent transducers were successively excited with appropriate delay times so as to generate a plane wave. The exposure direction was changed by exciting a different set of eight elements. For these feasibility studies, we used a cylindrical prototype (OD 10.6 mm) composed of 16 elementary transducers distributed over a quarter of the cylinder, all operating at 4.55 MHz. The active part was mechanically reinforced by a rigid damper structure behind the transducers. It was shown that an ultrasound field similar to that emitted by a plane transducer could be generated. Ex vivo experiments on pig's liver demonstrated that the ultrasound beam could be accurately rotated to generate sector-based lesions to a suitable depth (up to 19 mm). Throughout these experiments, exposures lasting 20 s were delivered at an acoustic intensity of 17 W cm -2 . By varying the power from exposure to exposure, the depth of the lesion at different angles could be controlled

  14. Cumulative phase delay imaging for contrast-enhanced ultrasound tomography

    International Nuclear Information System (INIS)

    Demi, Libertario; Van Sloun, Ruud J G; Wijkstra, Hessel; Mischi, Massimo

    2015-01-01

    Standard dynamic-contrast enhanced ultrasound (DCE-US) imaging detects and estimates ultrasound-contrast-agent (UCA) concentration based on the amplitude of the nonlinear (harmonic) components generated during ultrasound (US) propagation through UCAs. However, harmonic components generation is not specific to UCAs, as it also occurs for US propagating through tissue. Moreover, nonlinear artifacts affect standard DCE-US imaging, causing contrast to tissue ratio reduction, and resulting in possible misclassification of tissue and misinterpretation of UCA concentration. Furthermore, no contrast-specific modality exists for DCE-US tomography; in particular speed-of-sound changes due to UCAs are well within those caused by different tissue types. Recently, a new marker for UCAs has been introduced. A cumulative phase delay (CPD) between the second harmonic and fundamental component is in fact observable for US propagating through UCAs, and is absent in tissue. In this paper, tomographic US images based on CPD are for the first time presented and compared to speed-of-sound US tomography. Results show the applicability of this marker for contrast specific US imaging, with cumulative phase delay imaging (CPDI) showing superior capabilities in detecting and localizing UCA, as compared to speed-of-sound US tomography. Cavities (filled with UCA) which were down to 1 mm in diameter were clearly detectable. Moreover, CPDI is free of the above mentioned nonlinear artifacts. These results open important possibilities to DCE-US tomography, with potential applications to breast imaging for cancer localization. (fast track communication)

  15. Hemispherically in-phase precipitation variability over the last 1700 years in a Madagascar speleothem record

    Science.gov (United States)

    Scroxton, Nick; Burns, Stephen J.; McGee, David; Hardt, Ben; Godfrey, Laurie R.; Ranivoharimanana, Lovasoa; Faina, Peterson

    2017-05-01

    Paleoclimate studies of tropical rainfall have led to a recognition of a predominant pattern of anti-phase behavior between the Northern and Southern hemispheres at both orbital and millennial timescales. Less certain is how regional tropical rainfall patterns have changed in the late Holocene, under boundary conditions and on timescales which are most relevant to the tropics' response to a warming world. Several high-resolution southern hemisphere rainfall records are at odds with meridional movement of the mean Inter-Tropical Convergence Zone location as the major driver of Holocene tropical rainfall variability, with regional precipitation patterns resembling modern day El-Niño Southern Oscillation end members. To test emerging ideas on sub-millennial tropical rainfall variability, additional records from the southern hemisphere are required. We present a new speleothem δ18O record from Anjohibe Cave, northwestern Madagascar, which provides a quasi-annual record of monsoonal strength and precipitation amount for the last 1700 years. The majority of δ18O variability in the record is at the decadal scale, and shows little to no correlation with major climate indices or cyclical climate drivers. At lower frequencies, changes in mean speleothem δ18O show good correlation with other regional precipitation records both north and south of the equator. The regional coherency of tropical rainfall across the west Indian Ocean resembles expansion and contraction of the tropical rain belt and positive-Indian Ocean Dipole-like conditions at different timescales. The cause of this coherency could be related to symmetrical changes in continental sensible heating, or to a low frequency sea surface temperature climate mode.

  16. Time reversal and phase coherent music techniques for super-resolution ultrasound imaging

    Science.gov (United States)

    Huang, Lianjie; Labyed, Yassin

    2018-05-01

    Systems and methods for super-resolution ultrasound imaging using a windowed and generalized TR-MUSIC algorithm that divides the imaging region into overlapping sub-regions and applies the TR-MUSIC algorithm to the windowed backscattered ultrasound signals corresponding to each sub-region. The algorithm is also structured to account for the ultrasound attenuation in the medium and the finite-size effects of ultrasound transducer elements. A modified TR-MUSIC imaging algorithm is used to account for ultrasound scattering from both density and compressibility contrasts. The phase response of ultrasound transducer elements is accounted for in a PC-MUSIC system.

  17. Ultrasound of the coracoclavicular ligaments in the acute phase of an acromioclavicular disjunction: Comparison of radiographic, ultrasound and MRI findings

    Energy Technology Data Exchange (ETDEWEB)

    Faruch Bilfeld, Marie; Lapegue, Franck; Chiavassa Gandois, Helene; Bayol, Marie Aurelie; Sans, Nicolas [CHU Toulouse-Purpan, Service de Radiologie, Toulouse Cedex 9 (France); Bonnevialle, Nicolas [CHU Toulouse-Purpan, Service d' Orthopedie, Toulouse Cedex 9 (France)

    2017-02-15

    Acromioclavicular joint injuries are typically diagnosed by clinical and radiographic assessment with the Rockwood classification, which is crucial for treatment planning. The purpose of this study was to describe how the ultrasound findings of acromioclavicular joint injury compare with radiography and MRI findings. Forty-seven patients with suspected unilateral acromioclavicular joint injury after acute trauma were enrolled in this prospective study. All patients underwent digital radiography, ultrasound and 3T MRI. A modified Rockwood classification was used to evaluate the coracoclavicular ligaments. The classifications of acromioclavicular joint injuries diagnosed with radiography, ultrasound and MRI were compared. MRI was used as the gold standard. The agreement between the ultrasound and MRI findings was very good, with a correlation coefficient of 0.83 (95 % CI: 0.72-0.90; p < 0.0001). Ultrasound detected coracoclavicular ligament injuries with a sensitivity of 88.9 %, specificity of 90.0 %, positive predictive value of 92.3 % and negative predictive value of 85.7 %. The agreement between the ultrasound and radiography findings was poor, with a correlation coefficient of 0.69 (95 % CI: 0.51-0.82; p < 0.0001). Ultrasound is an effective examination for the diagnostic work-up of lesions of the coracoclavicular ligaments in the acute phase of an acromioclavicular injury. (orig.)

  18. Ultrasound of the coracoclavicular ligaments in the acute phase of an acromioclavicular disjunction: Comparison of radiographic, ultrasound and MRI findings

    International Nuclear Information System (INIS)

    Faruch Bilfeld, Marie; Lapegue, Franck; Chiavassa Gandois, Helene; Bayol, Marie Aurelie; Sans, Nicolas; Bonnevialle, Nicolas

    2017-01-01

    Acromioclavicular joint injuries are typically diagnosed by clinical and radiographic assessment with the Rockwood classification, which is crucial for treatment planning. The purpose of this study was to describe how the ultrasound findings of acromioclavicular joint injury compare with radiography and MRI findings. Forty-seven patients with suspected unilateral acromioclavicular joint injury after acute trauma were enrolled in this prospective study. All patients underwent digital radiography, ultrasound and 3T MRI. A modified Rockwood classification was used to evaluate the coracoclavicular ligaments. The classifications of acromioclavicular joint injuries diagnosed with radiography, ultrasound and MRI were compared. MRI was used as the gold standard. The agreement between the ultrasound and MRI findings was very good, with a correlation coefficient of 0.83 (95 % CI: 0.72-0.90; p < 0.0001). Ultrasound detected coracoclavicular ligament injuries with a sensitivity of 88.9 %, specificity of 90.0 %, positive predictive value of 92.3 % and negative predictive value of 85.7 %. The agreement between the ultrasound and radiography findings was poor, with a correlation coefficient of 0.69 (95 % CI: 0.51-0.82; p < 0.0001). Ultrasound is an effective examination for the diagnostic work-up of lesions of the coracoclavicular ligaments in the acute phase of an acromioclavicular injury. (orig.)

  19. Ultrasound

    Science.gov (United States)

    Ultrasound is a useful procedure for monitoring the baby's development in the uterus. Ultrasound uses inaudible sound waves to produce a two-dimensional image of the baby while inside the mother's ...

  20. A simple uniformity test for ultrasound phased arrays.

    Science.gov (United States)

    Dudley, Nicholas J; Woolley, Darren J

    2016-09-01

    It is difficult to test phased array ultrasound transducers for non functioning elements. We aimed to modify a widely performed test to improve its ease and effectiveness for these arrays. A paperclip was slowly moved along the transducer array, with the scanner operating in M-mode, imaging at a fundamental frequency with automatic gain and grey scale adjustment disabled. Non-functioning elements are identified by a dark vertical line in the image. The test was repeated several times for each transducer, looking for consistency of results. 2 transducers, with faults already shown by electronic transducer testing, were used to validate the method. 23 transducers in clinical use were tested. The results of the modified test on the 2 faulty transducers agreed closely with electronic transducer testing results. The test indicated faults in 5 of the 23 transducers in clinical use: 3 with a single failed element and 2 with non-uniform sensitivity. 1 transducer with non-uniform sensitivity had undergone lens repair; the new lens was visibly non-uniform in thickness and further testing showed a reduction in depth of penetration and a loss of elevational focus in comparison with a new transducer. The modified test is capable of detecting non-functioning elements. Further work is required to provide a better understanding of more subtle faults. Copyright © 2016 Associazione Italiana di Fisica Medica. All rights reserved.

  1. Enhancement of bone shadow region using local phase-based ultrasound transmission maps.

    Science.gov (United States)

    Hacihaliloglu, Ilker

    2017-06-01

    Ultrasound is increasingly being employed in different orthopedic procedures as an imaging modality for real-time guidance. Nevertheless, low signal-to-noise-ratio and different imaging artifacts continue to hamper the success of ultrasound-based procedures. Bone shadow region is an important feature indicating the presence of bone/tissue interface in the acquired ultrasound data. Enhancement and automatic detection of this region could improve the sensitivity of ultrasound for imaging bone and result in improved guidance for various orthopedic procedures. In this work, a method is introduced for the enhancement of bone shadow regions from B-mode ultrasound data. The method is based on the combination of three different image phase features: local phase tensor, local weighted mean phase angle, and local phase energy. The combined local phase image features are used as an input to an [Formula: see text] norm-based contextual regularization method which emphasizes uncertainty in the shadow regions. The enhanced bone shadow images are automatically segmented and compared against expert segmentation. Qualitative and quantitative validation was performed on 100 in vivo US scans obtained from five subjects by scanning femur and vertebrae bones. Validation against expert segmentation achieved a mean dice similarity coefficient of 0.88. The encouraging results obtained in this initial study suggest that the proposed method is promising enough for further evaluation. The calculated bone shadow maps could be incorporated into different ultrasound bone segmentation and registration approaches as an additional feature.

  2. Ultrasound

    Science.gov (United States)

    ... completed. Young children may need additional preparation. When scheduling an ultrasound for yourself or your child, ask ... of Privacy Practices Notice of Nondiscrimination Manage Cookies Advertising Mayo Clinic is a not-for-profit organization ...

  3. Ultrasound

    Science.gov (United States)

    ... reflect off body structures. A computer receives the waves and uses them to create a picture. Unlike with an x-ray or CT scan, this test does not use ionizing radiation. The test is done in the ultrasound ...

  4. Ultrasound Burst Phase Thermography (UBP) for applications in the automotive industry

    International Nuclear Information System (INIS)

    Zweschper, T.; Riegert, G.; Dillenz, A.; Busse, G.

    2003-01-01

    The use of elastic waves in combination with thermal waves allows to separate structural information about investigated components from defect specific thermal signatures. Ultrasound Burst Phase thermography (UBP) is an defect-selective and fast imaging tool for damage detection. This contribution presents results obtained on various kinds of problems related to modern automobile production (crack detection in grey cast iron and aluminum, characterization of adhesive-bonded joints etc.). Advances resulting from frequency modulated ultrasound excitation will be presented

  5. Simulation Based Investigation of Focusing Phased Array Ultrasound in Dissimilar Metal Welds

    Directory of Open Access Journals (Sweden)

    Hun-Hee Kim

    2016-02-01

    Full Text Available Flaws at dissimilar metal welds (DMWs, such as reactor coolant systems components, Control Rod Drive Mechanism (CRDM, Bottom Mounted Instrumentation (BMI etc., in nuclear power plants have been found. Notably, primary water stress corrosion cracking (PWSCC in the DMWs could cause significant reliability problems at nuclear power plants. Therefore, phased array ultrasound is widely used for inspecting surface break cracks and stress corrosion cracks in DMWs. However, inspection of DMWs using phased array ultrasound has a relatively low probability of detection of cracks, because the crystalline structure of welds causes distortion and splitting of the ultrasonic beams which propagates anisotropic medium. Therefore, advanced evaluation techniques of phased array ultrasound are needed for improvement in the probability of detection of flaws in DMWs. Thus, in this study, an investigation of focusing and steering phased array ultrasound in DMWs was carried out using a time reversal technique, and an adaptive focusing technique based on finite element method (FEM simulation. Also, evaluation of focusing performance of three different focusing techniques was performed by comparing amplitude of phased array ultrasonic signals scattered from the targeted flaw with three different time delays.

  6. Sensor Fusion Techniques for Phased-Array Eddy Current and Phased-Array Ultrasound Data

    Energy Technology Data Exchange (ETDEWEB)

    Arrowood, Lloyd F. [Y-12 National Security Complex, Oak Ridge, TN (United States)

    2018-03-15

    Sensor (or Data) fusion is the process of integrating multiple data sources to produce more consistent, accurate and comprehensive information than is provided by a single data source. Sensor fusion may also be used to combine multiple signals from a single modality to improve the performance of a particular inspection technique. Industrial nondestructive testing may utilize multiple sensors to acquire inspection data depending upon the object under inspection and the anticipated types of defects that can be identified. Sensor fusion can be performed at various levels of signal abstraction with each having its strengths and weaknesses. A multimodal data fusion strategy first proposed by Heideklang and Shokouhi that combines spatially scattered detection locations to improve detection performance of surface-breaking and near-surface cracks in ferromagnetic metals is shown using a surface inspection example and is then extended for volumetric inspections. Utilizing data acquired from an Olympus Omniscan MX2 from both phased array eddy current and ultrasound probes on test phantoms, single and multilevel fusion techniques are employed to integrate signals from the two modalities. Preliminary results demonstrate how confidence in defect identification and interpretation benefit from sensor fusion techniques. Lastly, techniques for integrating data into radiographic and volumetric imagery from computed tomography are described and results are presented.

  7. Synthesis Of Ultrasound Field Sources Based on Phase Screen Approximation

    Directory of Open Access Journals (Sweden)

    Sukhanov Dmitry

    2018-01-01

    Full Text Available Here is proposed the method for synthesizing the sources of an acoustic field on the basis of an approximation of the phase screen. The technology of manufacturing ultrasonic phased arrays providing the formation of a field of a given distribution is proposed. An experimental setup has been developed for the formation of a vortex field at a distance of 10 cm.

  8. Image-guided ultrasound phased arrays are a disruptive technology for non-invasive therapy.

    Science.gov (United States)

    Hynynen, Kullervo; Jones, Ryan M

    2016-09-07

    Focused ultrasound offers a non-invasive way of depositing acoustic energy deep into the body, which can be harnessed for a broad spectrum of therapeutic purposes, including tissue ablation, the targeting of therapeutic agents, and stem cell delivery. Phased array transducers enable electronic control over the beam geometry and direction, and can be tailored to provide optimal energy deposition patterns for a given therapeutic application. Their use in combination with modern medical imaging for therapy guidance allows precise targeting, online monitoring, and post-treatment evaluation of the ultrasound-mediated bioeffects. In the past there have been some technical obstacles hindering the construction of large aperture, high-power, densely-populated phased arrays and, as a result, they have not been fully exploited for therapy delivery to date. However, recent research has made the construction of such arrays feasible, and it is expected that their continued development will both greatly improve the safety and efficacy of existing ultrasound therapies as well as enable treatments that are not currently possible with existing technology. This review will summarize the basic principles, current statures, and future potential of image-guided ultrasound phased arrays for therapy.

  9. Drug Release from Phase-Changeable Nanodroplets Triggered by Low-Intensity Focused Ultrasound

    Science.gov (United States)

    Cao, Yang; Chen, Yuli; Yu, Tao; Guo, Yuan; Liu, Fengqiu; Yao, Yuanzhi; Li, Pan; Wang, Dong; Wang, Zhigang; Chen, Yu; Ran, Haitao

    2018-01-01

    Background: As one of the most effective triggers with high tissue-penetrating capability and non-invasive feature, ultrasound shows great potential for controlling the drug release and enhancing the chemotherapeutic efficacy. In this study, we report, for the first time, construction of a phase-changeable drug-delivery nanosystem with programmable low-intensity focused ultrasound (LIFU) that could trigger drug-release and significantly enhance anticancer drug delivery. Methods: Liquid-gas phase-changeable perfluorocarbon (perfluoropentane) and an anticancer drug (doxorubicin) were simultaneously encapsulated in two kinds of nanodroplets. By triggering LIFU, the nanodroplets could be converted into microbubbles locally in tumor tissues for acoustic imaging and the loaded anticancer drug (doxorubicin) was released after the microbubble collapse. Based on the acoustic property of shell materials, such as shell stiffness, two types of nanodroplets (lipid-based nanodroplets and PLGA-based nanodroplets) were activated by different acoustic pressure levels. Ultrasound irradiation duration and power of LIFU were tested and selected to monitor and control the drug release from nanodroplets. Various ultrasound energies were introduced to induce the phase transition and microbubble collapse of nanodroplets in vitro (3 W/3 min for lipid nanodroplets; 8 W/3 min for PLGA nanodroplets). Results: We detected three steps in the drug-releasing profiles exhibiting the programmable patterns. Importantly, the intratumoral accumulation and distribution of the drug with LIFU exposure were significantly enhanced, and tumor proliferation was substantially inhibited. Co-delivery of two drug-loaded nanodroplets could overcome the physical barriers of tumor tissues during chemotherapy. Conclusion: Our study provides a new strategy for the efficient ultrasound-triggered chemotherapy by nanocarriers with programmable LIFU capable of achieving the on-demand drug release. PMID:29507623

  10. A Wearable Transcranial Doppler Ultrasound Phased Array System.

    Science.gov (United States)

    Pietrangelo, Sabino J; Lee, Hae-Seung; Sodini, Charles G

    2018-01-01

     Practical deficiencies related to conventional transcranial Doppler (TCD) sonography have restricted its use and applicability. This work seeks to mitigate several such constraints through the development of a wearable, electronically steered TCD velocimetry system, which enables noninvasive measurement of cerebral blood flow velocity (CBFV) for monitoring applications with limited operator interaction. A highly-compact, discrete prototype system was designed and experimentally validated through flow phantom and preliminary human subject testing. The prototype system incorporates a custom two-dimensional transducer array and multi-channel transceiver electronics, thereby facilitating acoustic beamformation via phased array operation. Electronic steering of acoustic energy enables algorithmic system controls to map Doppler power throughout the tissue volume of interest and localize regions of maximal flow. Multi-focal reception permits dynamic vessel position tracking and simultaneous flow velocimetry over the time-course of monitoring. Experimental flow phantom testing yielded high correlation with concurrent flowmeter recordings across the expected range of physiological flow velocities. Doppler power mapping has been validated in both flow phantom and preliminary human subject testing, resulting in average vessel location mapping times testing. A wearable prototype CBFV measurement system capable of autonomous vessel search and tracking has been presented. Although flow phantom and preliminary human validation show promise, further human subject testing is necessary to compare velocimetry data against existing commercial TCD systems. Additional human subject testing must also verify acceptable vessel search and tracking performance under a variety of subject populations and motion dynamics-such as head movement and ambulation.

  11. Ultrasound of the coracoclavicular ligaments in the acute phase of an acromioclavicular disjonction: Comparison of radiographic, ultrasound and MRI findings.

    Science.gov (United States)

    Faruch Bilfeld, Marie; Lapègue, Franck; Chiavassa Gandois, Hélène; Bayol, Marie Aurélie; Bonnevialle, Nicolas; Sans, Nicolas

    2017-02-01

    Acromioclavicular joint injuries are typically diagnosed by clinical and radiographic assessment with the Rockwood classification, which is crucial for treatment planning. The purpose of this study was to describe how the ultrasound findings of acromioclavicular joint injury compare with radiography and MRI findings. Forty-seven patients with suspected unilateral acromioclavicular joint injury after acute trauma were enrolled in this prospective study. All patients underwent digital radiography, ultrasound and 3T MRI. A modified Rockwood classification was used to evaluate the coracoclavicular ligaments. The classifications of acromioclavicular joint injuries diagnosed with radiography, ultrasound and MRI were compared. MRI was used as the gold standard. The agreement between the ultrasound and MRI findings was very good, with a correlation coefficient of 0.83 (95 % CI: 0.72-0.90; p acromioclavicular injury. • Ultrasound is appropriate for acute acromioclavicular trauma due to its accessibility. • Ultrasound contributes to the diagnostic work-up of acute lesions of the coracoclavicular ligaments. • Ultrasound is appropriate in patients likely to benefit from surgical treatment. • Ultrasound could be a supplement to standard radiography in acute acromioclavicular trauma.

  12. Effects of microchannel confinement on acoustic vaporisation of ultrasound phase change contrast agents

    Science.gov (United States)

    Lin, Shengtao; Zhang, Ge; Hau Leow, Chee; Tang, Meng-Xing

    2017-09-01

    The sub-micron phase change contrast agent (PCCA) composed of a perfluorocarbon liquid core can be activated into gaseous state and form stable echogenic microbubbles for contrast-enhanced ultrasound imaging. It has shown great promise in imaging microvasculature, tumour microenvironment, and cancer cells. Although PCCAs have been extensively studied for different diagnostic and therapeutic applications, the effect of biologically geometrical confinement on the acoustic vaporisation of PCCAs is still not clear. We have investigated the difference in PCCA-produced ultrasound contrast enhancement after acoustic activation with and without a microvessel confinement on a microchannel phantom. The experimental results indicated more than one-order of magnitude less acoustic vaporisation in a microchannel than that in a free environment taking into account the attenuation effect of the vessel on the microbubble scattering. This may provide an improved understanding in the applications of PCCAs in vivo.

  13. Phase-Change Nanoparticles Using Highly Volatile Perfluorocarbons: Toward a Platform for Extravascular Ultrasound Imaging

    Directory of Open Access Journals (Sweden)

    Terry O. Matsunaga, Paul S. Sheeran, Samantha Luois, Jason E. Streeter, Lee B. Mullin, Bhaskar Banerjee, Paul A. Dayton

    2012-01-01

    Full Text Available Recent efforts using perfluorocarbon (PFC nanoparticles in conjunction with acoustic droplet vaporization has introduced the possibility of expanding the diagnostic and therapeutic capability of ultrasound contrast agents to beyond the vascular space. Our laboratories have developed phase-change nanoparticles (PCNs from the highly volatile PFCs decafluorobutane (DFB, bp =-2 °C and octafluoropropane (OFP, bp =-37 °C for acoustic droplet vaporization. Studies with commonly used clinical ultrasound scanners have demonstrated the ability to vaporize PCN emulsions with frequencies and mechanical indices that may significantly decrease tissue bioeffects. In addition, these contrast agents can be formulated to be stable at physiological temperatures and the perfluorocarbons can be mixed to modulate the balance between sensitivity to ultrasound and general stability. We herein discuss our recent efforts to develop finely-tuned diagnostic/molecular imaging agents for tissue interrogation. We discuss studies currently under investigation as well as potential diagnostic and therapeutic paradigms that may emerge as a result of formulating PCNs with low boiling point PFCs.

  14. Does the phase of menstrual cycle affect MR-guided focused ultrasound surgery of uterine leiomyomas?

    International Nuclear Information System (INIS)

    So, Minna J.; Fennessy, Fiona M.; Zou, Kelly H.; McDannold, Nathan; Hynynen, Kullervo; Jolesz, Ferenc A.; Stewart, Elizabeth A.; Rybicki, Frank J.; Tempany, Clare M.

    2006-01-01

    Purpose: To determine whether the phase of menstrual cycle at the time of MR-guided focused ultrasound surgery (MRgFUS) treatment for uterine leiomyomas affects treatment outcome. Methods: We enrolled all patients participating in a prospective phase III clinical trial from our center who completed 6 months of clinical and imaging follow-up. Patients with irregular cycles and those on oral contraceptives were excluded. Data prospectively documenting the date of the last menstrual period (LMP) at the time of treatment, length and duration of cycle, and raw symptom severity score (SSS) from the Uterine Fibroid Symptom and Quality of Life questionnaire, at baseline and 6 months were collected. Proliferative phase patients were determined retrospectively as those who were treated within less than 14 days from LMP; secretory phase patients were classified as those who were treated greater than 14 days from LMP. Results: A total of 58 patients were enrolled. There was no significant difference in the mean SSS at baseline and mean SSS at 6 months between patients treated in the proliferative versus secretory phase of the cycle. No significant difference in the SSS change from baseline to 6 months was seen between the two groups. Conclusions: Menstrual cycle phase does not influence MRgFUS treatment outcome. Symptomatic improvement occurs with treatment during either phase of the menstrual cycle. Thus, the scheduling of MRgFUS treatment need not be based upon the phase of the menstrual cycle

  15. Does the phase of menstrual cycle affect MR-guided focused ultrasound surgery of uterine leiomyomas?

    Energy Technology Data Exchange (ETDEWEB)

    So, Minna J. [Department of Radiology, Brigham and Women' s Hospital/Harvard Medical School, Boston, MA (United States); Fennessy, Fiona M. [Department of Radiology, Brigham and Women' s Hospital/Harvard Medical School, Boston, MA (United States); Zou, Kelly H. [Department of Radiology, Brigham and Women' s Hospital/Harvard Medical School, Boston, MA (United States); McDannold, Nathan [Department of Radiology, Brigham and Women' s Hospital/Harvard Medical School, Boston, MA (United States); Hynynen, Kullervo [Department of Radiology, Brigham and Women' s Hospital/Harvard Medical School, Boston, MA (United States); Jolesz, Ferenc A. [Department of Radiology, Brigham and Women' s Hospital/Harvard Medical School, Boston, MA (United States); Stewart, Elizabeth A. [Department of Obstetrics and Gynecology, Brigham and Women' s Hospital/Harvard Medical School, Boston, MA (United States); Rybicki, Frank J. [Department of Radiology, Brigham and Women' s Hospital/Harvard Medical School, Boston, MA (United States); Tempany, Clare M. [Department of Radiology, Brigham and Women' s Hospital/Harvard Medical School, Boston, MA (United States)]. E-mail: ctempanyafdhal@partners.org

    2006-08-15

    Purpose: To determine whether the phase of menstrual cycle at the time of MR-guided focused ultrasound surgery (MRgFUS) treatment for uterine leiomyomas affects treatment outcome. Methods: We enrolled all patients participating in a prospective phase III clinical trial from our center who completed 6 months of clinical and imaging follow-up. Patients with irregular cycles and those on oral contraceptives were excluded. Data prospectively documenting the date of the last menstrual period (LMP) at the time of treatment, length and duration of cycle, and raw symptom severity score (SSS) from the Uterine Fibroid Symptom and Quality of Life questionnaire, at baseline and 6 months were collected. Proliferative phase patients were determined retrospectively as those who were treated within less than 14 days from LMP; secretory phase patients were classified as those who were treated greater than 14 days from LMP. Results: A total of 58 patients were enrolled. There was no significant difference in the mean SSS at baseline and mean SSS at 6 months between patients treated in the proliferative versus secretory phase of the cycle. No significant difference in the SSS change from baseline to 6 months was seen between the two groups. Conclusions: Menstrual cycle phase does not influence MRgFUS treatment outcome. Symptomatic improvement occurs with treatment during either phase of the menstrual cycle. Thus, the scheduling of MRgFUS treatment need not be based upon the phase of the menstrual cycle.

  16. One-dimensional phased array with mechanical motion for conformal ultrasound hyperthermia

    International Nuclear Information System (INIS)

    Ju, Kuen-Cheng; Chen, Yung-Yaw; Lin, Win-Li; Kuo, Te-Son

    2003-01-01

    This paper investigates the feasibility of conformal heating for external ultrasound hyperthermia by using a phased array transducer with mechanical motion. In this system, a one-dimensional phased array is arranged on a shaft and moves along the shaft, while dynamically focusing on the planning target volume (PTV) with numerous focal spots. To prevent overheating in the intervening tissue between the skin and the PTV, the shaft and the phased array are rotated together to enlarge the acoustical window. With the purpose of conformal heating, the power deposition of the PTV is constructed by combinations of the focal spots and an iterative gradient descent method is then used to determine an optimal set of power weightings for the focal spots. Different tumour shapes are evaluated and the simulation results demonstrate that the volume percentage of the PTV with temperatures higher than 43 deg. C is over 95%. The overheating volume outside the PTV is less than 25% of the PTV. This method provides good conformal heating for external ultrasound hyperthermia. The concept of combining electrical focusing and mechanical motion has the advantages of both enlarging the acoustic window and providing dynamic focusing ability, which is essential for successful conformal heating

  17. Alteration of rhythmic unimanual tapping and anti-phase bimanual coordination in Alzheimer's disease: A sign of inter-hemispheric disconnection?

    Science.gov (United States)

    Martin, Elodie; Blais, Mélody; Albaret, Jean-Michel; Pariente, Jérémie; Tallet, Jessica

    2017-10-01

    Little attention is paid to motor control in Alzheimer's disease (AD) although it is a relevant sign of central nervous system integrity and functioning. In particular, unimanual and bimanual tapping is a relevant paradigm because it requires intra- and inter-hemispheric transfer (IHT). Previous results indicate that both unimanual and anti-phase tapping requires more IHT than in-phase tapping, especially produced without external stimulation. The aim of the present study was to test the production of unimanual, bimanual in-phase and anti-phase tapping with a synchronization-continuation paradigm with and without visual stimulation in AD patients (N=9) and control participants (N=12). In accordance with our hypothesis, these results suggest that unimanual and anti-phase tapping is more altered in AD than in control participants. Moreover, performance is globally more variable in the AD group. These alterations are discussed in terms of possible IHT modulation, in line with functional and structural findings in AD, revealing changes in the connectivity of brain regions across hemispheres and white matter damage. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Ultrasound pregnancy

    Science.gov (United States)

    Pregnancy sonogram; Obstetric ultrasonography; Obstetric sonogram; Ultrasound - pregnancy; IUGR - ultrasound; Intrauterine growth - ultrasound; Polyhydramnios - ultrasound; Oligohydramnios - ultrasound; ...

  19. Unilateral Hemispheric Encephalitis

    Directory of Open Access Journals (Sweden)

    Mohan Leslie Noone

    2014-10-01

    Full Text Available A 10 year old boy presented with history of mild fever and upper respiratory symptoms followed by recurrent seizures and loss of consciousness on the next day. Normal blood counts and abnormal hepatic transaminases were noted. MRI of the brain, done on the fourth day of illness, showed extensive involvement of the cortex in the right hemisphere. Lumbar CSF was normal. The EEG showed bilateral slowing with frontal sharp wave discharges and marked attenuation over the entire right hemisphere. The patient succumbed to the illness on the ninth day. A similar pattern of acute unilateral hemispheric cortical involvement is described in the hemiconvulsion-hemiplegia-epilepsy (HHE syndrome, which is typically described to occur in children below 4 years of age. This case of fulminant acute unilateral encaphilitic illness could represent the acute phase of HHE syndrome.

  20. Realtime control of multiple-focus phased array heating patterns based on noninvasive ultrasound thermography.

    Science.gov (United States)

    Casper, Andrew; Liu, Dalong; Ebbini, Emad S

    2012-01-01

    A system for the realtime generation and control of multiple-focus ultrasound phased-array heating patterns is presented. The system employs a 1-MHz, 64-element array and driving electronics capable of fine spatial and temporal control of the heating pattern. The driver is integrated with a realtime 2-D temperature imaging system implemented on a commercial scanner. The coordinates of the temperature control points are defined on B-mode guidance images from the scanner, together with the temperature set points and controller parameters. The temperature at each point is controlled by an independent proportional, integral, and derivative controller that determines the focal intensity at that point. Optimal multiple-focus synthesis is applied to generate the desired heating pattern at the control points. The controller dynamically reallocates the power available among the foci from the shared power supply upon reaching the desired temperature at each control point. Furthermore, anti-windup compensation is implemented at each control point to improve the system dynamics. In vitro experiments in tissue-mimicking phantom demonstrate the robustness of the controllers for short (2-5 s) and longer multiple-focus high-intensity focused ultrasound exposures. Thermocouple measurements in the vicinity of the control points confirm the dynamics of the temperature variations obtained through noninvasive feedback. © 2011 IEEE

  1. Intracavitary ultrasound phased arrays for prostate thermal therapies: MRI compatibility and in vivo testing.

    Science.gov (United States)

    Hutchinson, E B; Hynynen, K

    1998-12-01

    A 62 element MRI-compatible linear phased array was designed and constructed to investigate the feasibility of using transrectal ultrasound for the thermal therapeutic treatment of prostate cancer and benign prostatic hyperplasia. An aperiodic design technique developed in a previous study was used in the design of this array, which resulted in reduced grating lobe levels by using an optimized random distribution of unequally sized elements. The element sizes used in this array were selected to be favorable for both grating lobe levels as determined by array aperiodicity and array efficiency as determined by width to thickness ratios. The heating capabilities and MRI compatibility of the array were tested with in vivo rabbit thigh muscle heating experiments using MRI temperature monitoring. The array produced therapeutic temperature elevations in vivo at depths of 3-6 cm and axial locations up to 3 cm off the central axis and increased the size of the heated volume with electronic scanning of a single focus. The ability of this array to be used for ultrasound surgery was demonstrated by creating necrosed tissue lesions in vivo using short high-power sonications. The ability of the array to be used for hyperthermia was demonstrated by inducing therapeutic temperature elevations for longer exposures. Based on the acoustic and heating performance of this array, it has the potential to be clinically useful for delivering thermal therapies to the prostate and other target volumes close to body cavities.

  2. Thermal therapy for breast tumors by using a cylindrical ultrasound phased array with multifocus pattern scanning: a preliminary numerical study

    International Nuclear Information System (INIS)

    Ho, C-S; Ju, K-C; Cheng, T-Y; Chen, Y-Y; Lin, W-L

    2007-01-01

    The purpose of this study is to investigate the feasibility of using a 1 MHz cylindrical ultrasound phased array with multifocus pattern scanning to produce uniform heating for breast tumor thermal therapy. The breast was submerged in water and surrounded by the cylindrical ultrasound phased array. A multifocus pattern was generated and electrically scanned by the phased array to enlarge the treatment lesion in single heating. To prevent overheating normal tissues, a large planning target volume (PTV) would be divided into several planes with several subunits on each plane and sequentially treated with a cooling phase between two successive heatings of the subunit. Heating results for different target temperatures (T tgt ), blood perfusion rates and sizes of the PTV have been studied. Furthermore, a superficial breast tumor with different water temperatures was also studied. Results indicated that a higher target temperature would produce a slightly larger thermal lesion, and a higher blood perfusion rate would not affect the heating lesion size but increase the heating time significantly. The acoustic power deposition and temperature elevations in ribs can be minimized by orienting the acoustic beam from the ultrasound phased array approximately parallel to the ribs. In addition, a large acoustic window on the convex-shaped breast surface for the proposed ultrasound phased array and the cooling effect of water would prevent the skin overheating for the production of a lesion at any desired location. This study demonstrated that the proposed cylindrical ultrasound phased array can provide effective heating for breast tumor thermal therapy without overheating the skin and ribs within a reasonable treatment time

  3. Imaging of vaporised sub-micron phase change contrast agents with high frame rate ultrasound and optics

    Science.gov (United States)

    Lin, Shengtao; Zhang, Ge; Jamburidze, Akaki; Chee, Melisse; Hau Leow, Chee; Garbin, Valeria; Tang, Meng-Xing

    2018-03-01

    Phase-change ultrasound contrast agent (PCCA), or nanodroplet, shows promise as an alternative to the conventional microbubble agent over a wide range of diagnostic applications. Meanwhile, high-frame-rate (HFR) ultrasound imaging with microbubbles enables unprecedented temporal resolution compared to traditional contrast-enhanced ultrasound imaging. The combination of HFR ultrasound imaging and PCCAs can offer the opportunity to observe and better understand PCCA behaviour after vaporisation captures the fast phenomenon at a high temporal resolution. In this study, we utilised HFR ultrasound at frame rates in the kilohertz range (5-20 kHz) to image native and size-selected PCCA populations immediately after vaporisation in vitro within clinical acoustic parameters. The size-selected PCCAs through filtration are shown to preserve a sub-micron-sized (mean diameter  1 µm) that originate from native PCCA emulsion. The results demonstrate imaging signals with different amplitudes and temporal features compared to that of microbubbles. Compared with the microbubbles, both the B-mode and pulse-inversion (PI) signals from the vaporised PCCA populations were reduced significantly in the first tens of milliseconds, while only the B-mode signals from the PCCAs were recovered during the next 400 ms, suggesting significant changes to the size distribution of the PCCAs after vaporisation. It is also shown that such recovery in signal over time is not evident when using size-selective PCCAs. Furthermore, it was found that signals from the vaporised PCCA populations are affected by the amplitude and frame rate of the HFR ultrasound imaging. Using high-speed optical camera observation (30 kHz), we observed a change in particle size in the vaporised PCCA populations exposed to the HFR ultrasound imaging pulses. These findings can further the understanding of PCCA behaviour under HFR ultrasound imaging.

  4. A dual-mode hemispherical sparse array for 3D passive acoustic mapping and skull localization within a clinical MRI guided focused ultrasound device

    Science.gov (United States)

    Crake, Calum; Brinker, Spencer T.; Coviello, Christian M.; Livingstone, Margaret S.; McDannold, Nathan J.

    2018-03-01

    Previous work has demonstrated that passive acoustic imaging may be used alongside MRI for monitoring of focused ultrasound therapy. However, past implementations have generally made use of either linear arrays originally designed for diagnostic imaging or custom narrowband arrays specific to in-house therapeutic transducer designs, neither of which is fully compatible with clinical MR-guided focused ultrasound (MRgFUS) devices. Here we have designed an array which is suitable for use within an FDA-approved MR-guided transcranial focused ultrasound device, within the bore of a 3 Tesla clinical MRI scanner. The array is constructed from 5  ×  0.4 mm piezoceramic disc elements arranged in pseudorandom fashion on a low-profile laser-cut acrylic frame designed to fit between the therapeutic elements of a 230 kHz InSightec ExAblate 4000 transducer. By exploiting thickness and radial resonance modes of the piezo discs the array is capable of both B-mode imaging at 5 MHz for skull localization, as well as passive reception at the second harmonic of the therapy array for detection of cavitation and 3D passive acoustic imaging. In active mode, the array was able to perform B-mode imaging of a human skull, showing the outer skull surface with good qualitative agreement with MR imaging. Extension to 3D showed the array was able to locate the skull within  ±2 mm/2° of reference points derived from MRI, which could potentially allow registration of a patient to the therapy system without the expense of real-time MRI. In passive mode, the array was able to resolve a point source in 3D within a  ±10 mm region about each axis from the focus, detect cavitation (SNR ~ 12 dB) at burst lengths from 10 cycles to continuous wave, and produce 3D acoustic maps in a flow phantom. Finally, the array was used to detect and map cavitation associated with microbubble activity in the brain in nonhuman primates.

  5. Detecting failed elements on phased array ultrasound transducers using the Edinburgh Pipe Phantom

    Science.gov (United States)

    Inglis, Scott; Pye, Stephen D

    2016-01-01

    Aims Imaging faults with ultrasound transducers are common. Failed elements on linear and curvilinear array transducers can usually be detected with a simple image uniformity or ‘paperclip’ test. However, this method is less effective for phased array transducers, commonly used in cardiac imaging. The aim of this study was to assess whether the presence of failed elements could be detected through measurement of the resolution integral (R) using the Edinburgh Pipe Phantom. Methods A 128-element paediatric phased array transducer was studied. Failed elements were simulated using layered polyvinyl chloride (PVC) tape as an attenuator and measurements of resolution integral were carried out for several widths of attenuator. Results All widths of attenuator greater than 0.5 mm resulted in a significant reduction in resolution integral and low contrast penetration measurements compared to baseline (p tests to detect failed elements on phased array transducers. Particularly encouraging is the result for low contrast penetration as this is a quick and simple measurement to make and can be performed with many different test objects, thus enabling ‘in-the-field’ checks. PMID:27482276

  6. Ultrasound Microbubble Treatment Enhances Clathrin-Mediated Endocytosis and Fluid-Phase Uptake through Distinct Mechanisms.

    Directory of Open Access Journals (Sweden)

    Farnaz Fekri

    Full Text Available Drug delivery to tumors is limited by several factors, including drug permeability of the target cell plasma membrane. Ultrasound in combination with microbubbles (USMB is a promising strategy to overcome these limitations. USMB treatment elicits enhanced cellular uptake of materials such as drugs, in part as a result of sheer stress and formation of transient membrane pores. Pores formed upon USMB treatment are rapidly resealed, suggesting that other processes such as enhanced endocytosis may contribute to the enhanced material uptake by cells upon USMB treatment. How USMB regulates endocytic processes remains incompletely understood. Cells constitutively utilize several distinct mechanisms of endocytosis, including clathrin-mediated endocytosis (CME for the internalization of receptor-bound macromolecules such as Transferrin Receptor (TfR, and distinct mechanism(s that mediate the majority of fluid-phase endocytosis. Tracking the abundance of TfR on the cell surface and the internalization of its ligand transferrin revealed that USMB acutely enhances the rate of CME. Total internal reflection fluorescence microscopy experiments revealed that USMB treatment altered the assembly of clathrin-coated pits, the basic structural units of CME. In addition, the rate of fluid-phase endocytosis was enhanced, but with delayed onset upon USMB treatment relative to the enhancement of CME, suggesting that the two processes are distinctly regulated by USMB. Indeed, vacuolin-1 or desipramine treatment prevented the enhancement of CME but not of fluid phase endocytosis upon USMB, suggesting that lysosome exocytosis and acid sphingomyelinase, respectively, are required for the regulation of CME but not fluid phase endocytosis upon USMB treatment. These results indicate that USMB enhances both CME and fluid phase endocytosis through distinct signaling mechanisms, and suggest that strategies for potentiating the enhancement of endocytosis upon USMB treatment may

  7. Investigations in physical mechanism of the oxidative desulfurization process assisted simultaneously by phase transfer agent and ultrasound.

    Science.gov (United States)

    Bhasarkar, Jaykumar B; Chakma, Sankar; Moholkar, Vijayanand S

    2015-05-01

    This paper attempts to discern the physical mechanism of the oxidative desulfurization process simultaneously assisted by ultrasound and phase transfer agent (PTA). With different experimental protocols, an attempt is made to deduce individual beneficial effects of PTA and ultrasound on the oxidative desulfurization system, and also the synergy between the effects of PTA and ultrasound. Effect of PTA is more marked for mechanically stirred system due to mass transfer limitations, while intense emulsification due to ultrasound helps overcome the mass transfer limitations and reduces the extent of enhancement of oxidation by PTA. Despite application of PTA and ultrasound, the intrinsic factors and properties of the reactants such as polarity (and hence partition coefficient) and diffusivity have a crucial effect on the extent of oxidation. The intrinsic reactivity of the oxidant also plays a vital role, as seen from the extent of oxidation achieved with performic acid and peracetic acid. The interfacial transport of oxidant in the form of oxidant-PTA complex reduces the undesired consumption of oxidant by the reducing species formed during transient cavitation in organic medium, which helps effective utilization of oxidant towards desulfurization. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Ultraino: An Open Phased-Array System for Narrowband Airborne Ultrasound Transmission.

    Science.gov (United States)

    Marzo, Asier; Corkett, Tom; Drinkwater, Bruce W

    2018-01-01

    Modern ultrasonic phased-array controllers are electronic systems capable of delaying the transmitted or received signals of multiple transducers. Configurable transmit-receive array systems, capable of electronic steering and shaping of the beam in near real-time, are available commercially, for example, for medical imaging. However, emerging applications, such as ultrasonic haptics, parametric audio, or ultrasonic levitation, require only a small subset of the capabilities provided by the existing controllers. To meet this need, we present Ultraino, a modular, inexpensive, and open platform that provides hardware, software, and example applications specifically aimed at controlling the transmission of narrowband airborne ultrasound. Our system is composed of software, driver boards, and arrays that enable users to quickly and efficiently perform research in various emerging applications. The software can be used to define array geometries, simulate the acoustic field in real time, and control the connected driver boards. The driver board design is based on an Arduino Mega and can control 64 channels with a square wave of up to 17 Vpp and /5 phase resolution. Multiple boards can be chained together to increase the number of channels. The 40-kHz arrays with flat and spherical geometries are demonstrated for parametric audio generation, acoustic levitation, and haptic feedback.

  9. A random phased array device for delivery of high intensity focused ultrasound

    International Nuclear Information System (INIS)

    Hand, J W; Shaw, A; Sadhoo, N; Rajagopal, S; Dickinson, R J; Gavrilov, L R

    2009-01-01

    Randomized phased arrays can offer electronic steering of a single focus and simultaneous multiple foci concomitant with low levels of secondary maxima and are potentially useful as sources of high intensity focused ultrasound (HIFU). This work describes laboratory testing of a 1 MHz random phased array consisting of 254 elements on a spherical shell of radius of curvature 130 mm and diameter 170 mm. Acoustic output power and efficiency are measured for a range of input electrical powers, and field distributions for various single- and multiple-focus conditions are evaluated by a novel technique using an infrared camera to provide rapid imaging of temperature changes on the surface of an absorbing target. Experimental results show that the array can steer a single focus laterally to at least ±15 mm off axis and axially to more than ±15 mm from the centre of curvature of the array and patterns of four and five simultaneous foci ±10 mm laterally and axially whilst maintaining low intensity levels in secondary maxima away from the targeted area in good agreement with linear theoretical predictions. Experiments in which pork meat was thermally ablated indicate that contiguous lesions several cm 3 in volume can be produced using the patterns of multiple foci.

  10. A random phased array device for delivery of high intensity focused ultrasound.

    Science.gov (United States)

    Hand, J W; Shaw, A; Sadhoo, N; Rajagopal, S; Dickinson, R J; Gavrilov, L R

    2009-10-07

    Randomized phased arrays can offer electronic steering of a single focus and simultaneous multiple foci concomitant with low levels of secondary maxima and are potentially useful as sources of high intensity focused ultrasound (HIFU). This work describes laboratory testing of a 1 MHz random phased array consisting of 254 elements on a spherical shell of radius of curvature 130 mm and diameter 170 mm. Acoustic output power and efficiency are measured for a range of input electrical powers, and field distributions for various single- and multiple-focus conditions are evaluated by a novel technique using an infrared camera to provide rapid imaging of temperature changes on the surface of an absorbing target. Experimental results show that the array can steer a single focus laterally to at least +/-15 mm off axis and axially to more than +/-15 mm from the centre of curvature of the array and patterns of four and five simultaneous foci +/-10 mm laterally and axially whilst maintaining low intensity levels in secondary maxima away from the targeted area in good agreement with linear theoretical predictions. Experiments in which pork meat was thermally ablated indicate that contiguous lesions several cm(3) in volume can be produced using the patterns of multiple foci.

  11. Phase structuring in metal alloys: Ultrasound-assisted top-down approach to engineering of nanostructured catalytic materials.

    Science.gov (United States)

    Cherepanov, Pavel V; Andreeva, Daria V

    2017-03-01

    High intensity ultrasound (HIUS) is a novel and efficient tool for top-down nanostructuring of multi-phase metal systems. Ultrasound-assisted structuring of the phase in metal alloys relies on two main mechanisms including interfacial red/ox reactions and temperature driven solid state phase transformations which affect surface composition and morphology of metals. Physical and chemical properties of sonication medium strongly affects the structuring pathways as well as morphology and composition of catalysts. HIUS can serve as a simple, fast, and effective approach for the tuning of structure and surface properties of metal particles, opening the new perspectives in design of robust and efficient catalysts. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Ultrasound-Assisted Transient Liquid Phase Bonding of Magnesium Alloy Using Brass Interlayer in Air

    Institute of Scientific and Technical Information of China (English)

    Zhiwei Lai; Ruishan Xie; Chuan Pan; Xiaoguang Chen; Lei Liu; Wenxian Wang; Guisheng Zou

    2017-01-01

    The microstructure evolution and oxide film behavior in ultrasound-assisted transient liquid phase (U-TLP) bonding of Mg alloy were investigated by applying different ultrasonic time at 460℃ withbrass interlayer in air.The results indicated that with increasing ultrasonic time,brass interlayer disappeared gradually and the Mg-Cu-Zn eutectic compounds were formed.The eutectic compounds in the joint decreased as the ultrasonic time increased further.The oxide removal process was divided into four steps.Continuous oxide film at the interface was partially fractured by ultrasonic vibration,and then suspended into liquid by undermining eutectic reaction.After that,the suspended oxide film was broken into small oxide fragments by ultrasonic cavitation effect,which was finally squeezed out of the joint by ultrasonic squeeze action.In addition,the mechanical properties of the joints were investigated.The maximum shear strength of the joint reached 105 MPa,which was 100% of base metal.

  13. A novel power spectrum calculation method using phase-compensation and weighted averaging for the estimation of ultrasound attenuation.

    Science.gov (United States)

    Heo, Seo Weon; Kim, Hyungsuk

    2010-05-01

    An estimation of ultrasound attenuation in soft tissues is critical in the quantitative ultrasound analysis since it is not only related to the estimations of other ultrasound parameters, such as speed of sound, integrated scatterers, or scatterer size, but also provides pathological information of the scanned tissue. However, estimation performances of ultrasound attenuation are intimately tied to the accurate extraction of spectral information from the backscattered radiofrequency (RF) signals. In this paper, we propose two novel techniques for calculating a block power spectrum from the backscattered ultrasound signals. These are based on the phase-compensation of each RF segment using the normalized cross-correlation to minimize estimation errors due to phase variations, and the weighted averaging technique to maximize the signal-to-noise ratio (SNR). The simulation results with uniform numerical phantoms demonstrate that the proposed method estimates local attenuation coefficients within 1.57% of the actual values while the conventional methods estimate those within 2.96%. The proposed method is especially effective when we deal with the signal reflected from the deeper depth where the SNR level is lower or when the gated window contains a small number of signal samples. Experimental results, performed at 5MHz, were obtained with a one-dimensional 128 elements array, using the tissue-mimicking phantoms also show that the proposed method provides better estimation results (within 3.04% of the actual value) with smaller estimation variances compared to the conventional methods (within 5.93%) for all cases considered. Copyright 2009 Elsevier B.V. All rights reserved.

  14. Quantitative measurement of total cerebral blood flow using 2D phase-contrast MRI and doppler ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Keum Soo; Choi, Sun Seob; Lee, Young Il [Dong-A Univ., College of Medicine, Busan (Korea, Republic of)

    2001-12-01

    To compare of quantitative measurement of the total cerebral blood flow using two-dimensional phase-contrast MR imaging and Doppler ultrasound. In 16 volunteers (mean age, 26 years; mean body weight, 66 kg) without abnormal medical histories, two-dimensional phase-contrast MR imaging was performed at the level of the C2-3 inter vertebral disc for flow measurement of the internal carotid arteries and the vertebral arteries. Volume flow measurements using Doppler ultrasound were also performed at the internal carotid arteries 2cm above the carotid bifurcation, and at the vertebral arteries at the level of the upper pole of the thyroid gland. Flows in the four vessels measured by the two methods were compared using Wilcoxon's correlation analysis and the median score. Total cerebral blood flows were calculated by summing these four vessel flows, and mean values for the 16 volunteers were calculated. Cerebral blood flows measured by 2-D phase-contrast MR imaging and Doppler ultrasounds were 233 and 239 ml/min in the right internal carotid artery, 250 and 248 ml/min in the left internal carotid artery, 62 and 56 ml/min in the right vertebral artery, and 83 and 68 ml/min in the left vertebral artery. Correlation coefficients of the blood flows determined by the two methods were 0.48, 0.54, 0.49, and 0.62 in each vessel, while total cerebral blood flows were 628{+-}68 (range, 517 to 779) ml/min and 612{+-}79 (range, 482 to 804)ml/min, respectively. Total cerebral blood flow was easily measured using 2-D phase-contrast MR imaging and Doppler ultrasound, and the two noninvasive methods can therefore be used clinically for the measurement of total cerebral blood flow.

  15. The role of ultrasound in controlling the liquid-liquid phase separation and nucleation of vanillin polymorphs I and II

    Science.gov (United States)

    Parimaladevi, P.; Supriya, S.; Srinivasan, K.

    2018-02-01

    The influence of ultrasound on liquid-liquid phase separation (LLPS) and polymorphism of vanillin in aqueous solution has been investigated for the first time by varying the ultrasonic parameters such as power, pulse rate and insonation time at ambient condition. Results reveal that the application of ultrasound controls the impact of LLPS and accelerates the nucleation of vanillin within a short period at lower levels of ultrasonic process parameters, and also enhances the quality of the nucleated crystals. Moreover, the application of ultrasound induces the nucleation of rare and metastable polymorph of vanillin Form II in aqueous solution. But, at higher levels of power, pulse rate and insonation time, the rate of LLPS is found increased and the quality of the crystals becomes deteriorated. Morphology of the nucleated polymorphs were identified through optical microscopy and confirmed by optical goniometry. The internal structure and thermal stability of the grown stable Form I and metastable Form II of vanillin were confirmed through powder X-ray diffraction (PXRD) and differential scanning calorimetry (DSC) analyses. Further, results suggest that the ultrasound has profound effect in controlling the LLPS and nucleation of vanillin polymorphs in aqueous solution.

  16. The Interaction Between Dynamics and Chemistry of Ozone in the Set-up Phase of the Northern Hemisphere Polar Vortex

    Science.gov (United States)

    Kawa, S. R.; Bevilacqua, R.; Margitan, J. J.; Douglass, A. R.; Schoeberl, M. R.; Hoppel, K.; Sen, B.; Bhartia, P. K. (Technical Monitor)

    2001-01-01

    The morphology and evolution of the stratospheric ozone (O3) distribution at high latitudes in the Northern Hemisphere (NH) are examined for the late summer and fall seasons of 1999. This time period sets the O3 initial condition for the SOLVE/THESEO field mission performed during winter 1999-2000. In situ and satellite data are used along with a three-dimensional model of chemistry and transport (CTM) to determine the key processes that control the distribution of O3 in the lower-to-middle stratosphere. O3 in the vortex at the beginning of the winter season is found to be nearly constant from 500 to above 800 K with a value at 3 ppmv +/- approx. 10%. Values outside the vortex are up to a factor of 2 higher and increase significantly with potential temperature. The seasonal time series of data from POAM shows that relatively low O3 mixing ratios, which characterize the vortex in late fall, are already present at high latitudes at the end of summer before the vortex circulation sets up. Analysis of the CTM output shows that the minimum O3 and increase in variance in late summer are the result of: 1) stirring of polar concentric O3 gradients by nascent wave-driven transport, and 2) an acceleration of net photochemical loss with decreasing solar illumination. The segregation of low O3 mixing ratios into the vortex as the circulation strengthens through the fall suggests a possible feedback role between O3 chemistry and the vortex formation dynamics. Trajectory calculations from O3 sample points early in the fall, however, show only a weak correlation between initial O3 mixing ratio and potential vorticity later in the season consistent with order-of-magnitude calculations for the relative importance of O3 in the fall radiative balance at high latitudes. The possible connection between O3 chemistry and the dynamics of vortex formation does suggest that these feedbacks and sensitivities need to be better understood in order to make confident predictions of the recovery

  17. The relationship between experimental geometry, heat rate, and ultrasound wave speed measurement while observing phase changes in highly attenuative materials

    Science.gov (United States)

    Moore, David G.; Stair, Sarah L.; Jack, David A.

    2018-04-01

    Ultrasound techniques are capable of monitoring changes in the time-of-flight as a material is exposed to different thermal environments. The focus of the present study is to identify the phase of a material via ultrasound compression wave measurements in a through transmission experimental setup as the material is heated from a solid to a liquid and then allowed to re-solidify. The present work seeks to expand upon the authors' previous research, which proved this through transmission phase monitoring technique was possible, by considering different experimental geometries. The relationship between geometry, the measured speed of sound, and the temperature profile is presented. The use of different volumes helps in establishing a baseline understanding of which aspects of the experiment are geometry dependent and which are independent. The present study also investigates the relationship between the heating rate observed in the experiment and the measured speed of sound. The trends identified between the experimental geometry, heat rate and ultrasound wave speed measurement assist in providing a baseline understanding of the applicability of this technique to various industries, including the polymer industry and the oil industry.

  18. Focusing of high intensity ultrasound through the rib cage using a therapeutic random phased array

    Science.gov (United States)

    Bobkova, Svetlana; Gavrilov, Leonid; Khokhlova, Vera; Shaw, Adam; Hand, Jeffrey; #, ||

    2010-01-01

    A method for focusing high intensity ultrasound through a rib cage that aims to minimize heating of the ribs whilst maintaining high intensities at the focus (or foci) is proposed and tested theoretically and experimentally. Two approaches, one based on geometric acoustics and the other accounting for diffraction effects associated with propagation through the rib cage, are investigated theoretically for idealized source conditions. It is shown that for an idealized radiator the diffraction approach provides a 23% gain in peak intensity and results in significantly less power losses on the ribs (1% versus 7.5% of the irradiated power) compared with the geometric one. A 2D 1-MHz phased array with 254 randomly distributed elements, tissue mimicking phantoms, and samples of porcine rib cages are used in experiments; the geometric approach is used to configure how the array is driven. Intensity distributions are measured in the plane of the ribs and in the focal plane using an infra-red camera. Theoretical and experimental results show that it is possible to provide adequate focusing through the ribs without overheating them for a single focus and several foci, including steering at ± 10–15 mm off and ± 20 mm along the array axis. Focus splitting due to the periodic spatial structure of ribs is demonstrated both in simulations and experiments; the parameters of splitting are quantified. The ability to produce thermal lesions with a split focal pattern in ex vivo porcine tissue placed beyond the rib phantom is also demonstrated. The results suggest that the method is potentially useful for clinical applications of HIFU for which the rib cage lies between the transducer(s) and the targeted tissue. PMID:20510186

  19. Treatment time reduction for large thermal lesions by using a multiple 1D ultrasound phased array system

    International Nuclear Information System (INIS)

    Liu, H.-L.; Chen, Y.-Y.; Yen, J.-Y.; Lin, W.-L.

    2003-01-01

    To generate large thermal lesions in ultrasound thermal therapy, cooling intermissions are usually introduced during the treatment to prevent near-field heating, which leads to a long treatment time. A possible strategy to shorten the total treatment time is to eliminate the cooling intermissions. In this study, the two methods, power optimization and acoustic window enlargement, for reducing power accumulation in the near field are combined to investigate the feasibility of continuously heating a large target region (maximally 3.2 x 3.2 x 3.2 cm 3 ). A multiple 1D ultrasound phased array system generates the foci to scan the target region. Simulations show that the target region can be successfully heated without cooling and no near-field heating occurs. Moreover, due to the fact that there is no cooling time during the heating sessions, the total treatment time is significantly reduced to only several minutes, compared to the existing several hours

  20. Continuous-flow ultrasound assisted oxidative desulfurization (UAOD) process: An efficient diesel treatment by injection of the aqueous phase.

    Science.gov (United States)

    Rahimi, Masoud; Shahhosseini, Shahrokh; Movahedirad, Salman

    2017-11-01

    A new continuous-flow ultrasound assisted oxidative desulfurization (UAOD) process was developed in order to decrease energy and aqueous phase consumption. In this process the aqueous phase is injected below the horn tip leading to enhanced mixing of the phases. Diesel fuel as the oil phase with sulfur content of 1550ppmw and an appropriate mixture of hydrogen peroxide and formic acid as the aqueous phase were used. At the first step, the optimized condition for the sulfur removal has been obtained in the batch mode operation. Hence, the effect of more important oxidation parameters; oxidant-to-sulfur molar ratio, acid-to-sulfur molar ratio and sonication time were investigated. Then the optimized conditions were obtained using Response Surface Methodology (RSM) technique. Afterwards, some experiments corresponding to the best batch condition and also with objective of minimizing the residence time and aqueous phase to fuel volume ratio have been conducted in a newly designed double-compartment reactor with injection of the aqueous phase to evaluate the process in a continuous flow operation. In addition, the effect of nozzle diameter has been examined. Significant improvement on the sulfur removal was observed specially in lower sonication time in the case of dispersion method in comparison with the conventional contact between two phases. Ultimately, the flow pattern induced by ultrasonic device, and also injection of the aqueous phase were analyzed quantitatively and qualitatively by capturing the sequential images. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... Ultrasound - Abdomen Obstetric Ultrasound Ultrasound - Prostate Kidney and Bladder Stones Abnormal Vaginal Bleeding Ovarian Cancer Images related to Ultrasound - Pelvis Sponsored by Please ...

  2. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... Children's (Pediatric) Ultrasound - Abdomen Obstetric Ultrasound Ultrasound - Prostate Kidney and Bladder Stones Abnormal Vaginal Bleeding Ovarian Cancer Images related to Ultrasound - Pelvis Sponsored by Please ...

  3. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... specific content. Related Articles and Media Sonohysterography Ultrasound - Abdomen Children's (Pediatric) Ultrasound - Abdomen Obstetric Ultrasound Ultrasound - Prostate Kidney and ...

  4. MRI-guided Therapeutic Ultrasound : In vitro Validation of a New MR Compatible, Phased Array, Contact Endorectal Ultrasound Transducer with Active Feedback Control of Temperature Evolution

    Science.gov (United States)

    Salomir, Rares; Rata, Mihaela; Lafon, Cyril; Melodelima, David; Chapelon, Jean-Yves; Mathias, Adrien; Cotton, François; Bonmartin, Alain; Cathignol, Dominique

    2006-05-01

    Contact application of high intensity ultrasound was demonstrated to be suitable for thermal ablation of sectorial tumours of the digestive duct. Experimental validation of a new MR compatible ultrasonic device is described here, dedicated to the minimal invasive therapy of localized colorectal cancer. This is a cylindrical 1D 64-element phased array transducer of 14 mm diameter and 25 mm height (Imasonic, France) allowing electronic rotation of the acoustic beam. Operating frequency ranges from 3.5 to 4.0 MHz and up to 5 effective electrical watts per element are available. A plane wave is reconstructed by simultaneous excitation of eigth adjacent elements with an appropriate phase law. Driving electronics operates outside the Faraday cage of the scanner and provides fast switching capabilities. Excellent passive and active compatibility with the MRI data acquisition has been demonstrated. In addition, feasibility of active temperature control has been demonstrated based on real-time data export out of the MR scanner and a PID feedback algorithm. Further studies will address the in-vivo validation and the integration of a miniature NMR coil for increased SNR in the near field.

  5. Preoperative evaluation of hyperparathyroidism. The role of dual-phase parathyroid scintigraphy and ultrasound imaging

    International Nuclear Information System (INIS)

    Sukan, A.; Reyhan, M.; Aydin, M.; Yapar, A.F.; Aktas, A.; Sert, Y.; Canpolat, T.

    2008-01-01

    The aim of this study was to evaluate the efficacy of dual-phase 99mTc-methoxyisobutylnitrile (MIBI) parathyroid scintigraphy (PS) and ultrasound (US) in primary (pHPT) and secondary (sHPT) hyperparathyroidism. A total of 69 patients (mean age 47±16; age range 14-79 years), including 19 patients with sHPT were enrolled in this study. Preoperative serum intact parathyroid hormone (iPTH) levels, calcium (Ca), phosphate (P), alkaline phosphatase, and 24-h urinary-free Ca measurements were obtained. Concomitant thyroid pathology was also recorded. Histopathology revealed 30 solitary adenomas and 71 hyperplastic glands in 55 patients. The remaining patients' histopathology revealed normal parathyroid, thyroid, or lymph nodes. The sensitivities of MIBI and US in pUPT were 70% and 60%, respectively. It was 60% for both procedures in sHPT. The overall sensitivity of combined US+MIBI in pHPT and sHPT was 81% and 71%, respectively. The overall specificity of MIBI and US was 87% and 91%; positive predictive value (PPV) was 94% and 92%, respectively. MIBI and US identified the parathyroid pathology in 92% and 85% of patients in the non-concomitant thyroid disease group, and in 53% and 47% of patients in the concomitant thyroid disease group, respectively. The weight of the gland between primary and secondary hyperparathyroidism did not reveal a significant difference (P=0.4). Significant differences were found with respect to age, PTH, Ca, and P levels between the pHPT and sHPT (P<0.001). Intact PTH levels showed significant differences between MIBI positive and negative patients (P=0.013), and also US positive and negative patients (P=0.012). A significant negative correlation was found between iPTH and Ca at sHPT (P<0.001). The concomitancy of thyroid disease greatly influences scintigraphic and ultrasonographic detection of parathyroid pathology in pHPT and sHPT. The combination of MIBI and US appears promising for localizing parathyroid pathology in patients with both

  6. Immunogenicity and safety of Southern Hemisphere inactivated quadrivalent influenza vaccine: a Phase III, open-label study of adults in Brazil.

    Science.gov (United States)

    Zerbini, Cristiano A F; Ribeiro Dos Santos, Rodrigo; Jose Nunes, Maria; Soni, Jyoti; Li, Ping; Jain, Varsha K; Ofori-Anyinam, Opokua

    The World Health Organization influenza forecast now includes an influenza B strain from each of the influenza B lineages (B/Yamagata and B/Victoria) for inclusion in seasonal influenza vaccines. Traditional trivalent influenza vaccines include an influenza B strain from one lineage, but because two influenza B lineages frequently co-circulate, the effectiveness of trivalent vaccines may be reduced in seasons of influenza B vaccine-mismatch. Thus, quadrivalent vaccines may potentially reduce the burden of influenza compared with trivalent vaccines. In this Phase III, open-label study, we assessed the immunogenicity and safety of Southern Hemisphere inactivated quadrivalent influenza vaccine (Fluarix™ Tetra) in Brazilian adults (NCT02369341). The primary objective was to assess hemagglutination-inhibition antibody responses against each vaccine strain 21 days after vaccination in adults (aged ≥18-60 years) and older adults (aged >60 years). Solicited adverse events for four days post-vaccination, and unsolicited adverse events and serious adverse events for 21 days post-vaccination were also assessed. A total of 63 adults and 57 older adults received one dose of inactivated quadrivalent influenza vaccine at the beginning of the 2015 Southern Hemisphere influenza season. After vaccination, in adults and older adults, the hemagglutination-inhibition titers fulfilled the European licensure criteria for immunogenicity. In adults, the seroprotection rates with HI titer ≥1:40 were 100% (A/H1N1), 98.4% (A/H3N2), 100% (B/Yamagata), and 100% (B/Victoria); in older adults were 94.7% (A/H1N1), 96.5% (A/H3N2), 100% (B/Yamagata), and 100% (B/Victoria). Pain was the most common solicited local adverse events in adults (27/62) and in older adults (13/57), and the most common solicited general adverse events in adults was myalgia (9/62), and in older adults were myalgia and arthralgia (both 2/57). Unsolicited adverse events were reported by 11/63 adults and 10/57 older adults

  7. Rapid determination of the volatile components in tobacco by ultrasound-microwave synergistic extraction coupled to headspace solid-phase microextraction with gas chromatography-mass spectrometry.

    Science.gov (United States)

    Yang, Yanqin; Chu, Guohai; Zhou, Guojun; Jiang, Jian; Yuan, Kailong; Pan, Yuanjiang; Song, Zhiyu; Li, Zuguang; Xia, Qian; Lu, Xinbo; Xiao, Weiqiang

    2016-03-01

    An ultrasound-microwave synergistic extraction coupled to headspace solid-phase microextraction was first employed to determine the volatile components in tobacco samples. The method combined the advantages of ultrasound, microwave, and headspace solid-phase microextraction. The extraction, separation, and enrichment were performed in a single step, which could greatly simplify the operation and reduce the whole pretreatment time. In the developed method, several experimental parameters, such as fiber type, ultrasound power, and irradiation time, were optimized to improve sampling efficiency. Under the optimal conditions, there were 37, 36, 34, and 36 components identified in tobacco from Guizhou, Hunan, Yunnan, and Zimbabwe, respectively, including esters, heterocycles, alkanes, ketones, terpenoids, acids, phenols, and alcohols. The compound types were roughly the same while the contents were varied from different origins due to the disparity of their growing conditions, such as soil, water, and climate. In addition, the ultrasound-microwave synergistic extraction coupled to headspace solid-phase microextraction method was compared with the microwave-assisted extraction coupled to headspace solid-phase microextraction and headspace solid-phase microextraction methods. More types of volatile components were obtained by using the ultrasound-microwave synergistic extraction coupled to headspace solid-phase microextraction method, moreover, the contents were high. The results indicated that the ultrasound-microwave synergistic extraction coupled to headspace solid-phase microextraction technique was a simple, time-saving and highly efficient approach, which was especially suitable for analysis of the volatile components in tobacco. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. A resonant ultrasound spectroscopy study of the phase transitions in Na0.75CoO2

    Science.gov (United States)

    Keppens, Veerle; Sergienko, Ivan; Jin, Rongying

    2005-03-01

    The layered transition metal oxides NaxCoO2 have attracted much interest in the past few years. Crystals with the x˜0.75 composition undergo an order-disorder transition near 340 K, a spin-density-wave transition near 22 K and other subtle transitions at intermediate temperatures. These phase transitions, likely related to a rearrangement of the Na atoms among the available sites, have been mapped out using resonant ultrasound spectroscopy. The results are modeled within the Landau theory for second order phase transitions. [Oak Ridge National Laboratory is managed by UT-Battelle, LLC, for the U.S. Dept. of Energy under contract DE-AC05-00OR22725

  9. Prostate Ultrasound

    Medline Plus

    Full Text Available ... Physician Resources Professions Site Index A-Z Ultrasound - Prostate Ultrasound of the prostate uses sound waves to ... Ultrasound Imaging? What is Ultrasound Imaging of the Prostate? Ultrasound is safe and painless, and produces pictures ...

  10. Inverse effects of flowing phase-shift nanodroplets and lipid-shelled microbubbles on subsequent cavitation during focused ultrasound exposures.

    Science.gov (United States)

    Zhang, Siyuan; Cui, Zhiwei; Xu, Tianqi; Liu, Pan; Li, Dapeng; Shang, Shaoqiang; Xu, Ranxiang; Zong, Yujin; Niu, Gang; Wang, Supin; He, Xijing; Wan, Mingxi

    2017-01-01

    This paper compared the effects of flowing phase-shift nanodroplets (NDs) and lipid-shelled microbubbles (MBs) on subsequent cavitation during focused ultrasound (FUS) exposures. The cavitation activity was monitored using a passive cavitation detection method as solutions of either phase-shift NDs or lipid-shelled MBs flowed at varying velocities through a 5-mm diameter wall-less vessel in a transparent tissue-mimicking phantom when exposed to FUS. The intensity of cavitation for the phase-shift NDs showed an upward trend with time and cavitation for the lipid-shelled MBs grew to a maximum at the outset of the FUS exposure followed by a trend of decreases when they were static in the vessel. Meanwhile, the increase of cavitation for the phase-shift NDs and decrease of cavitation for the lipid-shelled MBs had slowed down when they flowed through the vessel. During two discrete identical FUS exposures, while the normalized inertial cavitation dose (ICD) value for the lipid-shelled MB solution was higher than that for the saline in the first exposure (p-value 0.95). Meanwhile, the normalized ICD value for the phase-shift NDs was 0.182 at a flow velocity of 5cm/s and increased to 0.188 at a flow velocity of 15cm/s. As the flow velocity increased to 20cm/s, the normalized ICD was 0.185 and decreased to 0.178 at a flow velocity of 30cm/s. At high acoustic power, the normalized ICD values for both the lipid-shelled MBs and the phase-shift NDs increased with increasing flow velocities from 5 to 30cm/s (r>0.95). The effects of the flowing phase-shift NDs vaporized into gas bubbles as cavitation nuclei on the subsequent cavitation were inverse to those of the flowing lipid-shelled MBs destroyed after focused ultrasound exposures. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Long-term hemispheric variation of the flare index

    International Nuclear Information System (INIS)

    Feng Song; Deng Lin-Hua; Xu Shi-Chun

    2013-01-01

    The long-term hemispheric variation of the flare index is investigated. It is found that, (1) the phase difference of the flare index between the northern and southern hemispheres is about 6–7 months, which is near the time delay between flare activity and sunspot activity; (2) both the dominant and phase-leading hemisphere of the flare index is the northern hemisphere in the considered time interval, implying that the hemispheric asynchrony of solar activity has a close connection with the N-S asymmetry of solar activity. (research papers)

  12. Noninvasive focused ultrasound stimulation can modulate phase-amplitude coupling between neuronal oscillations in the rat hippocampus

    Directory of Open Access Journals (Sweden)

    Yi Yuan

    2016-07-01

    Full Text Available Noninvasive focused ultrasound stimulation (FUS can be used to modulate neural activity with high spatial resolution. Phase-amplitude coupling (PAC between neuronal oscillations is tightly associated with cognitive processes, including learning, attention and memory. In this study, we investigated the effect of FUS on PAC between neuronal oscillations and established the relationship between the PAC index and ultrasonic intensity. The rat hippocampus was stimulated using focused ultrasound at different spatial-average pulse-average ultrasonic intensities (3.9 W/cm2, 9.6 W/cm2, and 19.2 W/cm2. The local field potentials (LFPs in the rat hippocampus were recorded before and after FUS. Then, we analyzed PAC between neuronal oscillations using a PAC calculation algorithm. Our results showed that FUS significantly modulated PAC between the theta (4-8 Hz and gamma (30-80 Hz bands and between the alpha (9-13 Hz and ripple (81-200 Hz bands in the rat hippocampus, and PAC increased with incremental increases in ultrasonic intensity.

  13. Prostate Ultrasound

    Medline Plus

    Full Text Available ... through blood vessels. Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions. Prostate ultrasound, also called transrectal ultrasound, provides ...

  14. A 63 element 1.75 dimensional ultrasound phased array for the treatment of benign prostatic hyperplasia

    Directory of Open Access Journals (Sweden)

    Smith Nadine

    2005-06-01

    Full Text Available Abstract Background Prostate cancer and benign prostatic hyperplasia are very common diseases in older American men, thus having a reliable treatment modality for both diseases is of great importance. The currently used treating options, mainly surgical ones, have numerous complications, which include the many side effects that accompany such procedures, besides the invasive nature of such techniques. Focused ultrasound is a relatively new treating modality that is showing promising results in treating prostate cancer and benign prostatic hyperplasia. Thus this technique is gaining more attention in the past decade as a non-invasive method to treat both diseases. Methods In this paper, the design, construction and evaluation of a 1.75 dimensional ultrasound phased array to be used for treating prostate cancer and benign prostatic hyperplasia is presented. With this array, the position of the focus can be controlled by changing the electrical power and phase to the individual elements for electronically focusing and steering in a three dimensional volume. The array was designed with a maximum steering angle of ± 13.5° in the transverse direction and a maximum depth of penetration of 11 cm, which allows the treatment of large prostates. The transducer piezoelectric ceramic, matching layers and cable impedance have been designed for maximum power transfer to tissue. Results To verify the capability of the transducer for focusing and steering, exposimetry was performed and the results correlated well with the calculated field. Ex vivo experiments using bovine tissue were performed with various lesion sizes and indicated the capability of the transducer to ablate tissue using short sonications. Conclusion A 1.75 dimensional array, that overcame the drawbacks associated with one-dimensional arrays, has been designed, built and successfully tested. Design issues, such as cable and ceramic capacitances, were taken into account when designing this

  15. Quantitative measurement of portal blood flow by magnetic resonance phase contrast. Comparative study of flow phantom and Doppler ultrasound in vivo

    International Nuclear Information System (INIS)

    Tsunoda, Masatoshi; Kimoto, Shin; Hamazaki, Keisuke; Takeda, Yoshihiro; Hiraki, Yoshio.

    1994-01-01

    A non-invasive method for measuring portal blood flow by magnetic resonance (MR) phase contrast was evaluated in a flow phantom and 20 healthy volunteers. In a flow phantom study, the flow volumes and mean flow velocities measured by MR phase contrast showed close correlations with those measured by electromagnetic flow-metry. In 20 healthy volunteers, the cross-sectional areas, flow volumes and mean flow velocities measured by MR phase contrast correlated well with those measured by the Doppler ultrasound method. Portal blood flow averaged during the imaging time could be measured under natural breathing conditions by using a large number of acquisitions without the limitations imposed on the Doppler ultrasound method. MR phase contrast is considered to be useful for the non-invasive measurement of portal blood flow. (author)

  16. Automatic bone outer contour extraction from B-modes ultrasound images based on local phase symmetry and quadratic polynomial fitting

    Science.gov (United States)

    Karlita, Tita; Yuniarno, Eko Mulyanto; Purnama, I. Ketut Eddy; Purnomo, Mauridhi Hery

    2017-06-01

    Analyzing ultrasound (US) images to get the shapes and structures of particular anatomical regions is an interesting field of study since US imaging is a non-invasive method to capture internal structures of a human body. However, bone segmentation of US images is still challenging because it is strongly influenced by speckle noises and it has poor image quality. This paper proposes a combination of local phase symmetry and quadratic polynomial fitting methods to extract bone outer contour (BOC) from two dimensional (2D) B-modes US image as initial steps of three-dimensional (3D) bone surface reconstruction. By using local phase symmetry, the bone is initially extracted from US images. BOC is then extracted by scanning one pixel on the bone boundary in each column of the US images using first phase features searching method. Quadratic polynomial fitting is utilized to refine and estimate the pixel location that fails to be detected during the extraction process. Hole filling method is then applied by utilize the polynomial coefficients to fill the gaps with new pixel. The proposed method is able to estimate the new pixel position and ensures smoothness and continuity of the contour path. Evaluations are done using cow and goat bones by comparing the resulted BOCs with the contours produced by manual segmentation and contours produced by canny edge detection. The evaluation shows that our proposed methods produces an excellent result with average MSE before and after hole filling at the value of 0.65.

  17. Protocol of plain radiographs, hip ultrasound, and triple phase bone scans in the evaluation of the painful pediatric hip

    International Nuclear Information System (INIS)

    Alexander, J.E.; Seibert, J.J.; Aronson, J.; Williamson, S.L.; Glasier, C.M.; Rodgers, A.B.; Corbitt, S.L.

    1988-01-01

    A useful protocol for the evaluation of hip pain in the pediatric patient, using a combination of plain radiographs, hip ultrasound (US), and triple phase radionuclide bone scans is presented. Patients with hip pain were initially evaluated by plain radiographs of the pelvis and hips. If no diagnosis was reached, the hips were studied for effusions by real-time hip ultrasonography. If an effusion was present, the joint was aspirated for diagnosis. If no effusion was present by US or if no diagnosis was reached by aspiration, triple phase radionuclide bone scans were performed. Fifty patients were evaluated by this prospective protocol, and the diagnosis was reached in 48 of the 50 cases (10 by plain radiographs, 16 by US, and aspiration of the joint, and 22 by triple phase bone scans). Hip effusions were found in 20 patients by US, with no false positives or false negatives. Previous studies for detecting effusions by US have emphasized absolute measurements of the capsular width, but we report a typical appearance of the hip capsule when fluid is present (a bulging convex capsule). When no effusion is present, the capsule is concave and parallels the long axis of the femoral neck

  18. Formulation and acoustic studies of a new phase-shift agent for diagnostic and therapeutic ultrasound.

    Science.gov (United States)

    Sheeran, Paul S; Luois, Samantha; Dayton, Paul A; Matsunaga, Terry O

    2011-09-06

    Recent efforts in the area of acoustic droplet vaporization with the objective of designing extravascular ultrasound contrast agents has led to the development of stabilized, lipid-encapsulated nanodroplets of the highly volatile compound decafluorobutane (DFB). We developed two methods of generating DFB droplets, the first of which involves condensing DFB gas (boiling point from -1.1 to -2 °C) followed by extrusion with a lipid formulation in HEPES buffer. Acoustic droplet vaporization of micrometer-sized lipid-coated droplets at diagnostic ultrasound frequencies and mechanical indices were confirmed optically. In our second formulation methodology, we demonstrate the formulation of submicrometer-sized lipid-coated nanodroplets based upon condensation of preformed microbubbles containing DFB. The droplets are routinely in the 200-300 nm range and yield microbubbles on the order of 1-5 μm once vaporized, consistent with ideal gas law expansion predictions. The simple and effective nature of this methodology allows for the development of a variety of different formulations that can be used for imaging, drug and gene delivery, and therapy. This study is the first to our knowledge to demonstrate both a method of generating ADV agents by microbubble condensation and formulation of primarily submicrometer droplets of decafluorobutane that remain stable at physiological temperatures. Finally, activation of DFB nanodroplets is demonstrated using pressures within the FDA guidelines for diagnostic imaging, which may minimize the potential for bioeffects in humans. This methodology offers a new means of developing extravascular contrast agents for diagnostic and therapeutic applications. © 2011 American Chemical Society

  19. Image-Guided Surgery of Primary Breast Cancer Using Ultrasound Phased Arrays

    National Research Council Canada - National Science Library

    Ebbini, Emad S

    2004-01-01

    .... Piezocomposite transducer technology, especially for phased arrays, is providing high-quality HIFU applicators with increased bandwidth and reduced parasitic cross coupling between the array elements...

  20. Prostate Ultrasound

    Medline Plus

    Full Text Available ... ultrasound or with a rectal examination, an ultrasound-guided biopsy can be performed. This procedure involves advancing ... of the Prostate) Prostate Cancer Ultrasound- and MRI-Guided Prostate Biopsy Images related to Ultrasound - Prostate Sponsored ...

  1. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... Ultrasound - Pelvis Ultrasound imaging of the pelvis uses sound waves to produce pictures of the structures and ... pictures of the inside of the body using sound waves. Ultrasound imaging, also called ultrasound scanning or ...

  2. Prostate Ultrasound

    Medline Plus

    Full Text Available ... Z Ultrasound - Prostate Ultrasound of the prostate uses sound waves to produce pictures of a man’s prostate ... pictures of the inside of the body using sound waves. Ultrasound imaging, also called ultrasound scanning or ...

  3. Ultrasound -- Pelvis

    Science.gov (United States)

    ... endometrial polyps fibroids cancer, especially in patients with abnormal uterine bleeding Some physicians also use 3-D ultrasound or ... Obstetric Ultrasound Ultrasound - Prostate Kidney and Bladder Stones Abnormal Vaginal Bleeding Ovarian Cancer Images related to Ultrasound - Pelvis Sponsored ...

  4. Effect of contrast-enhanced ultrasound on differential diagnosis of intrahepatic cholangiocarcinoma and arterial phase enhanced hepatic inflammatory lesions

    Institute of Scientific and Technical Information of China (English)

    Shanshan Yin; Qiuli Cui; Kun Yan; Wei Yang; Wei Wu; Liping Bao; Minhua Chen

    2017-01-01

    Objective:To investigate differential diagnosis between intrahepatic cholangiocarcinoma (ICC) and arterial phase enhanced hepatic inflammatory lesions in patients without liver cirrhosis using contrast-enhanced ultrasound (CEUS).Methods:ICC and hepatic inflammatory lesions cases with CEUS and pathological diagnosis between Sep 2013 and Oct 2016 were investigated retrospectively.Imaging features of conventional ultrasound and CEUS were analyzed.The parameters of time intensity curve (TIC),including the arrival time,peak intensity (PI) in the lesions,the starting time for washout,and the intensity difference at 3 min (△I3) after contrast agent infection between the lesion and the liver parenchyma,were compared between ICC and hepatic inflammatory lesions.Results:Twenty-five ICC and fifteen inflammatory patients were included in this study.Seventeen ICC (68.0%) and two inflammatory cases (13.3%) showed bile duct dilatation on conventional ultrasound.Using CEUS,three ICC cases (12.0%) were misdiagnosed as inflammatory lesions and three inflammatory lesions (20.0%) as ICC;two ICC (8.0%) and one inflammatory case (6.7%) could not be made definite diagnosis.Washout started at 34.5±3.5 s and 61.5± 12.9 s for ICC and inflammatory lesions respectively (P<0.001).The intensity difference between lesion and liver parenchyma at 3 min after contrast agent injection was 10.8±3.1 dB in ICC and 4.2±2.3 dB in inflammatory group (P<0.00 1).The sensitivity and specificity differentiating ICC and inflammatory lesions were 76% and 87% if the cut-offvalue of the intensity difference was 7.7 dB.Conclusions:Combined with TIC analysis,and particularly with the characteristic of the early-starting and obvious washout in ICC,CEUS can be useful in differential diagnosis between hepatic inflammatory lesions and ICC.

  5. Northern Hemisphere forcing of Southern Hemisphere climate during the last deglaciation.

    Science.gov (United States)

    He, Feng; Shakun, Jeremy D; Clark, Peter U; Carlson, Anders E; Liu, Zhengyu; Otto-Bliesner, Bette L; Kutzbach, John E

    2013-02-07

    According to the Milankovitch theory, changes in summer insolation in the high-latitude Northern Hemisphere caused glacial cycles through their impact on ice-sheet mass balance. Statistical analyses of long climate records supported this theory, but they also posed a substantial challenge by showing that changes in Southern Hemisphere climate were in phase with or led those in the north. Although an orbitally forced Northern Hemisphere signal may have been transmitted to the Southern Hemisphere, insolation forcing can also directly influence local Southern Hemisphere climate, potentially intensified by sea-ice feedback, suggesting that the hemispheres may have responded independently to different aspects of orbital forcing. Signal processing of climate records cannot distinguish between these conditions, however, because the proposed insolation forcings share essentially identical variability. Here we use transient simulations with a coupled atmosphere-ocean general circulation model to identify the impacts of forcing from changes in orbits, atmospheric CO(2) concentration, ice sheets and the Atlantic meridional overturning circulation (AMOC) on hemispheric temperatures during the first half of the last deglaciation (22-14.3 kyr BP). Although based on a single model, our transient simulation with only orbital changes supports the Milankovitch theory in showing that the last deglaciation was initiated by rising insolation during spring and summer in the mid-latitude to high-latitude Northern Hemisphere and by terrestrial snow-albedo feedback. The simulation with all forcings best reproduces the timing and magnitude of surface temperature evolution in the Southern Hemisphere in deglacial proxy records. AMOC changes associated with an orbitally induced retreat of Northern Hemisphere ice sheets is the most plausible explanation for the early Southern Hemisphere deglacial warming and its lead over Northern Hemisphere temperature; the ensuing rise in atmospheric CO(2

  6. The utility of sparse 2D fully electronically steerable focused ultrasound phased arrays for thermal surgery: a simulation study

    International Nuclear Information System (INIS)

    Ellens, Nicholas; Pulkkinen, Aki; Song Junho; Hynynen, Kullervo

    2011-01-01

    Sparse arrays are widely used in diagnostic ultrasound for their strong performance and relative technical simplicity. This simulation study assessed the efficacy of phased arrays of varied sparseness for thermal surgery, especially with regard to power consumption and near-field heating. It employs a linear ultrasound propagation model and a semi-analytical solution to the Pennes' bioheat transfer equation. The basic design had 4912 cylindrical transducers (500 kHz) arranged on a flat 12 cm disk (1.5 mm spacing). This array was compared to randomly-thinned sparse arrays with 75%, 50% and 25% populations. Temperature elevations of 60 and 70 deg. C were induced in sonication times of 5-20 s, at foci spanning depths of 50-150 mm and radii of 0-60 mm. The sparse arrays produced nearly indistinguishable focal patterns but, averaged across the foci, required 132%, 200% and 393% of the power of the full array, respectively, applied through fewer transducer elements. Comparable results were found at 1 MHz from equivalent arrays. Simulated lesions were formed (thermal dose ≥ 240 equivalent minutes at 43 deg. C (T 43 )) and 'transition' and 'unsafe' regions (both defined as 5 min 43 < 240 min) were identified, the former immediately surrounding the lesion and the latter anywhere else. At a depth of 100 mm, sparse arrays were found to produce comparable lesions to the full array at the focus, but 'unsafe', over-heated near-field regions after some ablated lesion volume: about 12 mL for the 25% array, around 100 mL for the 50% array, while the 75% and full arrays produced 150 mL lesions safely.

  7. Spatial and temporal observation of phase-shift nano-emulsions assisted cavitation and ablation during focused ultrasound exposure.

    Science.gov (United States)

    Qiao, Yangzi; Zong, Yujin; Yin, Hui; Chang, Nan; Li, Zhaopeng; Wan, Mingxi

    2014-09-01

    Phase-shift nano-emulsions (PSNEs) with a small initial diameter in nanoscale have the potential to leak out of the blood vessels and to accumulate at the target point of tissue. At desired location, PSNEs can undergo acoustic droplet vaporization (ADV) process, change into gas bubbles and enhance focused ultrasound efficiency. The threshold of droplet vaporization and influence of acoustic parameters have always been research hotspots in order to spatially control the potential of bioeffects and optimize experimental conditions. However, when the pressure is much higher than PSNEs' vaporization threshold, there were little reports on their cavitation and thermal effects. In this study, PSNEs induced cavitation and ablation effects during pulsed high-intensity focused ultrasound (HIFU) exposure were investigated, including the spatial and temporal information and the influence of acoustic parameters. Two kinds of tissue-mimicking phantoms with uniform PSNEs were prepared because of their optical transparency. The Sonoluminescence (SL) method was employed to visualize the cavitation activities. And the ablation process was observed as the heat deposition could produce white lesion. Precisely controlled HIFU cavitation and ablation can be realized at a relatively low input power. But when the input power was high, PSNEs can accelerate cavitation and ablation in pre-focal region. The cavitation happened layer by layer advancing the transducer. While the lesion appeared to be separated into two parts, one in pre-focal region stemmed from one point and grew quickly, the other in focal region grew much more slowly. The influence of duty cycle has also been examined. Longer pulse off time would cause heat transfer to the surrounding media, and generate smaller lesion. On the other hand, this would give outer layer bubbles enough time to dissolve, and inner bubbles can undergo violent collapse and emit bright light. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Combined passive acoustic mapping and magnetic resonance thermometry for monitoring phase-shift nanoemulsion enhanced focused ultrasound therapy

    Science.gov (United States)

    Crake, Calum; Meral, F. Can; Burgess, Mark T.; Papademetriou, Iason T.; McDannold, Nathan J.; Porter, Tyrone M.

    2017-08-01

    Focused ultrasound (FUS) has the potential to enable precise, image-guided noninvasive surgery for the treatment of cancer in which tumors are identified and destroyed in a single integrated procedure. However, success of the method in highly vascular organs has been limited due to heat losses to perfusion, requiring development of techniques to locally enhance energy absorption and heating. In addition, FUS procedures are conventionally monitored using MRI, which provides excellent anatomical images and can map temperature, but is not capable of capturing the full gamut of available data such as the acoustic emissions generated during this inherently acoustically-driven procedure. Here, we employed phase-shift nanoemulsions (PSNE) embedded in tissue phantoms to promote cavitation and hence temperature rise induced by FUS. In addition, we incorporated passive acoustic mapping (PAM) alongside simultaneous MR thermometry in order to visualize both acoustic emissions and temperature rise, within the bore of a full scale clinical MRI scanner. Focal cavitation of PSNE could be resolved using PAM and resulted in accelerated heating and increased the maximum elevated temperature measured via MR thermometry compared to experiments without nanoemulsions. Over time, the simultaneously acquired acoustic and temperature maps show translation of the focus of activity towards the FUS transducer, and the magnitude of the increase in cavitation and focal shift both increased with nanoemulsion concentration. PAM results were well correlated with MRI thermometry and demonstrated greater sensitivity, with the ability to detect cavitation before enhanced heating was observed. The results suggest that PSNE could be beneficial for enhancement of thermal focused ultrasound therapies and that PAM could be a critical tool for monitoring this process.

  9. In vitro parameter optimization for spatial control of focused ultrasound ablation when using low boiling point phase-change nanoemulsions.

    Science.gov (United States)

    Puett, Connor; Phillips, Linsey C; Sheeran, Paul S; Dayton, Paul A

    2013-01-01

    Phase-shift nanoemulsions (PSNEs) provide cavitation sites when the perfluorocarbon (PFC) nanodroplets (ND) are vaporized to microbubbles by acoustic energy. Their presence lowers the power required to ablate tissue by high-intensity focused ultrasound (HIFU), potentially making it a safer option for a broader range of treatment sites. However, spatial control over the ablation region can be problematic when cavitation is used to enhance heating. This study explored relationships between vaporization, ablation, and the PSNE concentration in vitro to optimize the acoustic intensity and insonation time required for spatially controlled ablation enhancement using a PSNE that included a volatile PFC component. HIFU (continuous wave at 1 MHz; insonation times of 5, 10, 15, and 20 s; cool-down times of 2, 4, and 6 s; peak negative pressures of 2, 3, and 4 MPa) was applied to albumin-acrylamide gels containing PFC agents (1:1 mix of volatile decafluorobutane and more stable dodecafluoropentane at 10(5) to 10(8) PFC ND per milliliter) or agent-free controls. Vaporization fields (microbubble clouds) were imaged by conventional ultrasound, and ablation lesions were measured directly by calipers. Controlled ablation was defined as the production of 'cigar'-shaped lesions corresponding with the acoustic focal zone. This control was considered to be lost when ablation occurred in prefocal vaporization fields having a predominantly 'tadpole' or oblong shape. Changes in the vaporization field shape and location occurred on a continuum with increasing PSNE concentration and acoustic intensity. Working with the maximum concentration-intensity combinations resulting in controlled ablation demonstrated a dose-responsive relationship between insonation time and volumes of both the vaporization fields (approximately 20 to 240 mm(3)) and the ablation lesions (1 to 135 mm(3)) within them. HIFU ablation was enhanced by this PSNE and could be achieved using intensities ≤650 W/cm(2

  10. Enhanced cavitation and heating of flowing polymer- and lipid-shelled microbubbles and phase-shift nanodroplets during focused ultrasound exposures

    Science.gov (United States)

    Zhang, Siyuan; Cui, Zhiwei; Li, Chong; Zhou, Fanyu; Zong, Yujin; Wang, Supin; Wan, Mingxi

    2017-03-01

    Cavitation and heating are the primary mechanisms of numerous therapeutic applications of ultrasound. Various encapsulated microbubbles (MBs) and phase-shift nanodroplets (NDs) have been used to enhance local cavitation and heating, creating interests in developing ultrasound therapy using these encapsulated MBs and NDs. This work compared the efficiency of flowing polymer- and lipid-shelled MBs and phase-shift NDs in cavitation and heating during focused ultrasound (FUS) exposures. Cavitation activity and temperature were investigated when the solution of polymer- and lipid-shelled MBs and NDs flowed through the vessel in a tissue-mimicking phantom with varying flow velocities when exposed to FUS at various acoustic power levels. The inertial cavitation dose (ICD) for the encapsulated MBs and NDs were higher than those for the saline. Temperature initially increased with increasing flow velocities of the encapsulated MBs, followed by a decrease of the temperature with increasing flow velocities when the velocity was much higher. Meanwhile, ICD showed a trend of increases with increasing flow velocity. For the phase-shift NDs, ICD after the first FUS exposure was lower than those after the second FUS exposure. For the encapsulated MBs, ICD after the first FUS exposure was higher than those after the second FUS exposure. Further studies are necessary to investigate the treatment efficiency of different encapsulated MBs and phase-shift NDs in cavitation and heating.

  11. Selective determination of caffeine in foods with 3D-graphene based ultrasound-assisted magnetic solid phase extraction.

    Science.gov (United States)

    Rahimi, Afshin; Zanjanchi, Mohammad Ali; Bakhtiari, Sadjad; Dehsaraei, Mohammad

    2018-10-01

    An efficient method was applied for extraction of caffeine in food samples. Three-dimensional graphene-Fe 3 O 4 (3D-G-Fe 3 O 4 ) nanoparticles was successfully synthesized and used as adsorbent in magnetic solid phase extraction (MSPE) step. The properties of synthesized adsorbent were characterized by fourier-transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), vibrating sample magnetometer (VSM), X-ray diffraction (XRD), Raman spectroscopy, Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) methods. The influence of main parameters of extraction procedure such as ultrasound parameter, amount of nanoparticles, pH, salt concentration and desorption condition were investigated and optimized. Under the optimized experimental conditions, the figure of merit results showed excellent linear dynamic range (LDR) of 0.5-500 µg mL -1 , with determination coefficient (R 2 ) higher than 0.996 and limit of detection (LOD) of 0.1 µg mL -1 . Intra- and inter-day relative standard deviations (RSDs) were less than 5.9 and 7.1%, respectively. The method was successfully applied for determination of caffeine in different food samples. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. An evaluation of the sonoporation potential of low-boiling point phase-change ultrasound contrast agents in vitro.

    Science.gov (United States)

    Fix, Samantha M; Novell, Anthony; Yun, Yeoheung; Dayton, Paul A; Arena, Christopher B

    2017-01-01

    Phase-change ultrasound contrast agents (PCCAs) offer a solution to the inherent limitations associated with using microbubbles for sonoporation; they are characterized by prolonged circulation lifetimes, and their nanometer-scale sizes may allow for passive accumulation in solid tumors. As a first step towards the goal of extravascular cell permeabilization, we aim to characterize the sonoporation potential of a low-boiling point formulation of PCCAs in vitro. Parameters to induce acoustic droplet vaporization and subsequent microbubble cavitation were optimized in vitro using high-speed optical microscopy. Sonoporation of pancreatic cancer cells in suspension was then characterized at a range of pressures (125-600 kPa) and pulse lengths (5-50 cycles) using propidium iodide as an indicator molecule. We achieved sonoporation efficiencies ranging from 8 ± 1% to 36 ± 4% (percent of viable cells), as evidenced by flow cytometry. Increasing sonoporation efficiency trended with increasing pulse length and peak negative pressure. We conclude that PCCAs can be used to induce the sonoporation of cells in vitro, and our results warrant further investigation into the use of PCCAs as extravascular sonoporation agents in vivo.

  13. Inspection of copper canisters for spent nuclear fuel by means of ultrasound. Phased arrays, ultrasonic imaging and nonlinear acoustics

    Energy Technology Data Exchange (ETDEWEB)

    Stepinski, Tadeusz (ed.); Ping Wu; Wennerstroem, Erik [Uppsala Univ. (Sweden). Signals and Systems

    2004-09-01

    This report contains the research results concerning advanced ultrasound for the inspection of copper canisters for spent nuclear fuel obtained at Signals and Systems, Uppsala University in years 2003/2004. After a short introduction a review of beam forming fundamentals required for proper understanding phased array operation is included. The factors that determine lateral resolution during ultrasonic imaging of flaws in solids are analyzed and results of simulations modelling contact inspection of copper are presented. In the second chapter an improved synthetic aperture imaging (SAI) technique is introduced. The proposed SAI technique is characterized by an enhanced lateral resolution compared with the previously proposed extended synthetic aperture focusing technique (ESAFT). The enhancement of imaging performance is achieved due to more realistic assumption concerning the probability density function of scatterers in the region of interest. The proposed technique takes the form of a two-step algorithm using the result obtained in the first step as a prior for the second step. Final chapter contains summary of our recent experimental and theoretical research on nonlinear ultrasonics of unbounded interfaces. A new theoretical model for rough interfaces is developed, and the experimental results from the copper specimens that mimic contact cracks of different types are presented. Derivation of the theory and selected measurement results are given in appendix.

  14. Prehospital Ultrasound

    Directory of Open Access Journals (Sweden)

    Jen-Tang Sun

    2014-06-01

    Full Text Available Ultrasound is a commonly used diagnostic tool in clinical conditions. With recent developments in technology, use of portable ultrasound devices has become feasible in prehospital settings. Many studies also proved the feasibility and accuracy of prehospital ultrasound. In this article, we focus on the use of prehospital ultrasound, with emphasis on trauma and chest ultrasound.

  15. The effect of high-power ultrasound and gas phase plasma treatment on Aspergillus spp. and Penicillium spp. count in pure culture.

    Science.gov (United States)

    Herceg, Z; Režek Jambrak, A; Vukušić, T; Stulić, V; Stanzer, D; Milošević, S

    2015-01-01

    The aim of this study was to investigate and compare two nonthermal techniques in the inactivation of moulds. High power ultrasound (20 kHz) and nonthermal gas phase plasma treatments were studied in the inactivation of selected moulds. Aspergillus spp. and Penicillium spp. were chosen as the most common mould present in or on food. Experimental design was introduced to establish and optimize working variables. For high power ultrasound, the greatest reduction of moulds (indicated by the total removal of viable cells) was obtained after ultrasound treatments at 60°C (thermosonication) for 6 and 9 min (power applied, 20-39 W). For plasma treatment, the greatest inactivation of moulds was observed for the longest treatment time (5 min) and lowest sample volume (2 ml), (AP12, AP13, PP12 and PP13). The great amount of applied energy required for achieving a partial log reduction in viable cells is the limiting factor for using high-power ultrasound. However, both treatment methods could be combined in the future to produce beneficial outcomes. This study deals with nonthermal food processing techniques and the results and findings present in this study are the root for further prospective studies. The food industry is looking for nonthermal methods that will enable food preservation, reduce deterioration of food compounds and structure and prolong food shelf life. © 2014 The Society for Applied Microbiology.

  16. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... a pelvic ultrasound examination. Doppler ultrasound , also called color Doppler ultrasonography, is a special ultrasound technique that ... and processes the sounds and creates graphs or color pictures that represent the flow of blood through ...

  17. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions. There are ... Ultrasound page for more information . Ultrasound examinations can help diagnose symptoms experienced by women such as: pelvic ...

  18. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... three types of pelvic ultrasound: abdominal, vaginal (for women), and rectal (for men). These exams are frequently ... pelvic ultrasound: abdominal ( transabdominal ) vaginal ( transvaginal / endovaginal ) for women rectal ( transrectal ) for men A Doppler ultrasound exam ...

  19. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... ultrasound images are captured in real-time, they can show the structure and movement of the body's ... Obstetrical Ultrasound page for more information . Ultrasound examinations can help diagnose symptoms experienced by women such as: ...

  20. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... through blood vessels. Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions. There are three types of pelvic ultrasound: ...

  1. [Determination of Arsenic in Food Package Aluminum by Ultrasound Assisted Solid Phase Extraction/ICP-AES].

    Science.gov (United States)

    Qin, Wen-xia; Gong, Qi; Li, Min; Deng, Li-xin; Mo, Li-shu; Li, Yan-lin

    2015-04-01

    Determination of arsenic in pure aluminum by inductively coupled plasma atomic emission spectrometry was interfered by aluminum matrix. The experiment showed that when the mass concentration of Al was greater than or equal to 5 000 times the As in the test solution, the measurement error was greater than 5%. In order to eliminate the interference, strong acid cation exchange fiber (SACEF) was used as solid phase extraction agent to adsorb Al(3+). The extraction conditions included amount of SACEF, extraction time, temperature and pH were investigated. The optimal extraction conditions were that 0.9000 g SACEF was used to extract the aluminum from the sample solution of pH 2.0 at 55 °C for 5 min with the ultrasonic assist, and in this case, the arsenic in the form of arsenic acid was not extracted and left in the solution for the determination. The results showed that after treating 10. 00 mL test solution containing 1.00 µg arsenic and 20.0 mg aluminum, arsenic did not lose. The mass concentration of residual aluminum in the raffinate was about 2,000 times the As, which had not interfered the determination of arsenic. The detection limit (3 s) was 0.027 µg · mL(-1) and quantification limit (10 s) was 0.0091 µg · mL(-1). The proposed method was successfully applied to the separation and determination of arsenic in the synthetic samples, the aluminum cans and the barbecue aluminum foil. Recovery was in the range of 98.3%-105% and RSD (n = 3) was in the range of 0.1%-4.3%. The results showed that the content of arsenic in the aluminum cans and the aluminum barbecue foil was below the limited value of national standard (GB/T 3190-2008).

  2. Reliability of mechanical and phased-array designs for serial intravascular ultrasound examinations--animal and clinical studies in stented and non-stented coronary arteries.

    Science.gov (United States)

    Tardif, J C; Bertrand, O F; Mongrain, R; Lespérance, J; Grégoire, J; Paiement, P; Bonan, R

    2000-10-01

    Both mechanical and multi-element intravascular ultrasound designs have potential advantages and limitations that may impact on their value for clinical and research purposes. Determination of the reproducibility of measurements is critical before a given system can be used in studies such as regression of atherosclerosis trials. We performed serial intravascular ultrasound imaging with catheters using mechanical and phased-array designs in stented and non-stented coronary arteries in dogs and in patients. Both systems correlated well for areas (r > or = 0.90, p or = 0.84. p mechanical designs for measurements of area (mean difference in dogs and in patients: -0.24 and 0.96 mm2, p mechanical system (r > or = 0.96 for all measurements). The differences in absolute and relative variability between the mechanical and phased-array designs, both for reanalysis of same frames and serial pullbacks, were very small. Although multi-element and mechanical intravascular ultrasound designs are not strictly interchangeable, their similar reproducibility and the small differences in measurements demonstrate that both designs are acceptable alternatives for trials of regression of atherosclerosis. Determination of the variability for serial pullbacks of both designs was also important to assess the statistical power of such trials.

  3. Simultaneous in situ derivatization and ultrasound-assisted dispersive magnetic solid phase extraction for thiamine determination by spectrofluorimetry.

    Science.gov (United States)

    Tarigh, Ghazale Daneshvar; Shemirani, Farzaneh

    2014-06-01

    A simple and rapid method for the simultaneous in situ derivatizaion, preconcentration and extraction of thiamine (vitamin B1) as a model analyte was developed by a novel quantitative method, namely ultrasound-assisted dispersive magnetic solid phase extraction spectrofluorimetry (USA-DMSPE-FL) from different real samples. This method consists of sample preparation, in situ derivatization, exhaustive extraction and clean up by a single process. High extraction efficiency and in situ derivatization in a short period of time is the main advantages of this procedure. For this purpose, the reusable magnetic multi-wall carbon nanotube (MMWCNT) nanocomposite was used as an adsorbent for preconcentration and determination of thiamine. Thiamine was, simultaneously, in situ derivatized as thiochrome by potassium hexacyanoferrate (III) and adsorbed on MMWCNT in an ultrasonic water bath. The MMWCNTs were then collected using an external magnetic field. Subsequently, the extracted thiochrome was washed from the surface of the adsorbent and determined by spectrofluorimetry. The developed method, which has been analytically characterized under its optimal operating conditions, allows the detection of the analyte in the samples with method detection limits of 0.37 µg L(-1). The repeatability of the method, expressed as the relative standard deviation (RSD, n=6), varies between 2.0% and 4.8% in different real samples, while the enhancement factor is 197. The proposed procedure has been applied for the determination of thiamine in biological (serum and urine), pharmaceutical (multivitamin tablet and B complex syrup) and foodstuff samples (cereal, wheat flour, banana and honey) with the good recoveries in the range from 90% to 105%. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Cavitation-enhanced MR-guided focused ultrasound ablation of rabbit tumors in vivo using phase shift nanoemulsions

    Science.gov (United States)

    Kopechek, Jonathan A.; Park, Eun-Joo; Zhang, Yong-Zhi; Vykhodtseva, Natalia I.; McDannold, Nathan J.; Porter, Tyrone M.

    2014-07-01

    Advanced tumors are often inoperable due to their size and proximity to critical vascular structures. High intensity focused ultrasound (HIFU) has been developed to non-invasively thermally ablate inoperable solid tumors. However, the clinical feasibility of HIFU ablation therapy has been limited by the long treatment times (on the order of hours) and high acoustic intensities required. Studies have shown that inertial cavitation can enhance HIFU-mediated heating by generating broadband acoustic emissions that increase tissue absorption and accelerate HIFU-induced heating. Unfortunately, initiating inertial cavitation in tumors requires high intensities and can be unpredictable. To address this need, phase-shift nanoemulsions (PSNE) have been developed. PSNE consist of lipid-coated liquid perfluorocarbon droplets that are less than 200 nm in diameter, thereby allowing passive accumulation in tumors through leaky tumor vasculature. PSNE can be vaporized into microbubbles in tumors in order to nucleate cavitation activity and enhance HIFU-mediated heating. In this study, MR-guided HIFU treatments were performed on intramuscular rabbit VX2 tumors in vivo to assess the effect of vaporized PSNE on acoustic cavitation and HIFU-mediated heating. HIFU pulses were delivered for 30 s using a 1.5 MHz, MR-compatible transducer, and cavitation emissions were recorded with a 650 kHz ring hydrophone while temperature was monitored using MR thermometry. Cavitation emissions were significantly higher (P cavitation which correlates with enhanced HIFU-mediated heating in tumors. This suggests that PSNE could potentially be used to reduce the time and/or acoustic intensity required for HIFU-mediated heating, thereby increasing the feasibility and clinical efficacy of HIFU thermal ablation therapy.

  5. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... Radiation Therapy for Gynecologic Cancers Radiation Therapy for Prostate Cancer top of page This page was reviewed on ... Abdomen Children's (Pediatric) Ultrasound - Abdomen Obstetric Ultrasound Ultrasound - Prostate Kidney and Bladder Stones Abnormal Vaginal Bleeding ... Images related to Ultrasound - Pelvis Sponsored by Please ...

  6. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... endometrial polyps fibroids cancer, especially in patients with abnormal uterine bleeding Some physicians also use 3-D ultrasound or ... Obstetric Ultrasound Ultrasound - Prostate Kidney and Bladder Stones Abnormal Vaginal Bleeding Ovarian Cancer Images related to Ultrasound - Pelvis Sponsored ...

  7. Trace determination of safranin O dye using ultrasound assisted dispersive solid-phase micro extraction: Artificial neural network-genetic algorithm and response surface methodology.

    Science.gov (United States)

    Dil, Ebrahim Alipanahpour; Ghaedi, Mehrorang; Asfaram, Arash; Mehrabi, Fatemeh; Bazrafshan, Ali Akbar; Ghaedi, Abdol Mohammad

    2016-11-01

    In this study, ultrasound assisted dispersive solid-phase micro extraction combined with spectrophotometry (USA-DSPME-UV) method based on activated carbon modified with Fe2O3 nanoparticles (Fe2O3-NPs-AC) was developed for pre-concentration and determination of safranin O (SO). It is known that the efficiency of USA-DSPME-UV method may be affected by pH, amount of adsorbent, ultrasound time and eluent volume and the extent and magnitude of their contribution on response (in term of main and interaction part) was studied by using central composite design (CCD) and artificial neural network-genetic algorithms (ANN-GA). Accordingly by adjustment of experimental conditions suggested by ANN-GA at pH 6.5, 1.1mg of adsorbent, 10min ultrasound and 150μL of eluent volume led to achievement of best operation performance like low LOD (6.3ngmL(-1)) and LOQ (17.5ngmL(-1)) in the range of 25-3500ngmL(-1). In following stage, the SO content in real water and wastewater samples with recoveries between 93.27-99.41% with RSD lower than 3% was successfully determined. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Homogeneous (Cu, Ni)6Sn5 intermetallic compound joints rapidly formed in asymmetrical Ni/Sn/Cu system using ultrasound-induced transient liquid phase soldering process.

    Science.gov (United States)

    Li, Z L; Dong, H J; Song, X G; Zhao, H Y; Tian, H; Liu, J H; Feng, J C; Yan, J C

    2018-04-01

    Homogeneous (Cu, Ni) 6 Sn 5 intermetallic compound (IMC) joints were rapidly formed in asymmetrical Ni/Sn/Cu system by an ultrasound-induced transient liquid phase (TLP) soldering process. In the traditional TLP soldering process, the intermetallic joints formed in Ni/Sn/Cu system consisted of major (Cu, Ni) 6 Sn 5 and minor Cu 3 Sn IMCs, and the grain morphology of (Cu, Ni) 6 Sn 5 IMCs subsequently exhibited fine rounded, needlelike and coarse rounded shapes from the Ni side to the Cu side, which was highly in accordance with the Ni concentration gradient across the joints. However, in the ultrasound-induced TLP soldering process, the intermetallic joints formed in Ni/Sn/Cu system only consisted of the (Cu, Ni) 6 Sn 5 IMCs which exhibited an uniform grain morphology of rounded shape with a remarkably narrowed Ni concentration gradient. The ultrasound-induced homogeneous intermetallic joints exhibited higher shear strength (61.6 MPa) than the traditional heterogeneous intermetallic joints (49.8 MPa). Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Cavitation-enhanced MR-guided focused ultrasound ablation of rabbit tumors in vivo using phase shift nanoemulsions

    International Nuclear Information System (INIS)

    Kopechek, Jonathan A; Porter, Tyrone M; Park, Eun-Joo; Zhang, Yong-Zhi; Vykhodtseva, Natalia I; McDannold, Nathan J

    2014-01-01

    Advanced tumors are often inoperable due to their size and proximity to critical vascular structures. High intensity focused ultrasound (HIFU) has been developed to non-invasively thermally ablate inoperable solid tumors. However, the clinical feasibility of HIFU ablation therapy has been limited by the long treatment times (on the order of hours) and high acoustic intensities required. Studies have shown that inertial cavitation can enhance HIFU-mediated heating by generating broadband acoustic emissions that increase tissue absorption and accelerate HIFU-induced heating. Unfortunately, initiating inertial cavitation in tumors requires high intensities and can be unpredictable. To address this need, phase-shift nanoemulsions (PSNE) have been developed. PSNE consist of lipid-coated liquid perfluorocarbon droplets that are less than 200 nm in diameter, thereby allowing passive accumulation in tumors through leaky tumor vasculature. PSNE can be vaporized into microbubbles in tumors in order to nucleate cavitation activity and enhance HIFU-mediated heating. In this study, MR-guided HIFU treatments were performed on intramuscular rabbit VX2 tumors in vivo to assess the effect of vaporized PSNE on acoustic cavitation and HIFU-mediated heating. HIFU pulses were delivered for 30 s using a 1.5 MHz, MR-compatible transducer, and cavitation emissions were recorded with a 650 kHz ring hydrophone while temperature was monitored using MR thermometry. Cavitation emissions were significantly higher (P < 0.05) after PSNE injection and this was well correlated with enhanced HIFU-mediated heating in tumors. The peak temperature rise induced by sonication was significantly higher (P < 0.05) after PSNE injection. For example, the mean per cent change in temperature achieved at 5.2 W of acoustic power was 46 ± 22% with PSNE injection. The results indicate that PSNE nucleates cavitation which correlates with enhanced HIFU-mediated heating in tumors. This suggests that PSNE could

  10. Young's moduli of sputter-deposited NiTi films determined by resonant ultrasound spectroscopy: Austenite, R-phase, and martensite

    Czech Academy of Sciences Publication Activity Database

    Thomasová, M.; Sedlák, Petr; Seiner, Hanuš; Janovská, Michaela; Kabla, M.; Shilo, D.; Landa, Michal

    2015-01-01

    Roč. 101, May (2015), s. 24-27 ISSN 1359-6462 R&D Projects: GA ČR GA14-15264S Grant - others:Rada Programu interní podpory projektů mezinárodní spolupráce AV ČR(CZ) M100761203 Program:M Institutional support: RVO:61388998 Keywords : shape memory alloys * sputtering * elastic behavior * martensitic phase transformation * resonant ultrasound spectroscopy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.305, year: 2015 http://www.sciencedirect.com/science/article/pii/S1359646215000238

  11. Selective determination of inorganic cobalt in nutritional supplements by ultrasound-assisted temperature-controlled ionic liquid dispersive liquid phase microextraction and electrothermal atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Berton, Paula; Martinis, Estefanía M.; Martinez, Luis D.; Wuilloud, Rodolfo G.

    2012-01-01

    Highlights: ► Synergy of ultrasound energy and TILDLME technique for improved metal extraction. ► Highly selective determination of inorganic Co species at trace levels. ► Speciation analysis of Co in several nutritional supplements with highly complex matrices. ► Development of an environmentally friendly microextraction technique with minimal waste production and sample consumption. - Abstract: In the present work, a simple and rapid analytical method based on application of ionic liquids (ILs) for inorganic Co(II) species (iCo) microextraction in a variety of nutrient supplements was developed. Inorganic Co was initially chelated with 1-nitroso-2-naphtol (1N2N) reagent followed by a modern technique named ultrasound-assisted temperature-controlled ionic liquid dispersive liquid phase microextraction (USA-TILDLME). The extraction was performed with 1-hexyl-3-methylimidazolium hexafluorophosphate [C 6 mim][PF 6 ] with the aid of ultrasound to improve iCo recovery. Finally, the iCo-enriched IL phase was solubilized in methanol and directly injected into an electrothermal atomic absorption spectrometer (ETAAS). Several parameters that could influence iCo microextraction and detection were carefully studied. Since the main difficulty in these samples is caused by high concentrations of potential interfering ions, different approaches were evaluated to eliminate interferences. The limit of detection (LOD) was 5.4 ng L −1 , while the relative standard deviation (RSD) was 4.7% (at 0.5 μg L −1 Co level and n = 10), calculated from the peak height of absorbance signals. Selective microextraction of iCo species was achieved only by controlling the pH value during the procedure. The method was thus successfully applied for determination of iCo species in nutritional supplements.

  12. Selective determination of inorganic cobalt in nutritional supplements by ultrasound-assisted temperature-controlled ionic liquid dispersive liquid phase microextraction and electrothermal atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Berton, Paula; Martinis, Estefania M. [Analytical Chemistry Research and Development Group (QUIANID), (LISAMEN-CCT-CONICET-Mendoza), Av. Ruiz Leal S/N Parque General San Martin, M 5502 IRA Mendoza (Argentina); Martinez, Luis D. [INQUISAL-CONICET, Departamento de Quimica Analitica, Facultad de Quimica, Bioquimica y Farmacia, Universidad Nacional de San Luis, San Luis (Argentina); Wuilloud, Rodolfo G., E-mail: rwuilloud@mendoza-conicet.gob.ar [Analytical Chemistry Research and Development Group (QUIANID), (LISAMEN-CCT-CONICET-Mendoza), Av. Ruiz Leal S/N Parque General San Martin, M 5502 IRA Mendoza (Argentina); Instituto de Ciencias Basicas, Universidad Nacional de Cuyo, Mendoza (Argentina)

    2012-02-03

    Highlights: Black-Right-Pointing-Pointer Synergy of ultrasound energy and TILDLME technique for improved metal extraction. Black-Right-Pointing-Pointer Highly selective determination of inorganic Co species at trace levels. Black-Right-Pointing-Pointer Speciation analysis of Co in several nutritional supplements with highly complex matrices. Black-Right-Pointing-Pointer Development of an environmentally friendly microextraction technique with minimal waste production and sample consumption. - Abstract: In the present work, a simple and rapid analytical method based on application of ionic liquids (ILs) for inorganic Co(II) species (iCo) microextraction in a variety of nutrient supplements was developed. Inorganic Co was initially chelated with 1-nitroso-2-naphtol (1N2N) reagent followed by a modern technique named ultrasound-assisted temperature-controlled ionic liquid dispersive liquid phase microextraction (USA-TILDLME). The extraction was performed with 1-hexyl-3-methylimidazolium hexafluorophosphate [C{sub 6}mim][PF{sub 6}] with the aid of ultrasound to improve iCo recovery. Finally, the iCo-enriched IL phase was solubilized in methanol and directly injected into an electrothermal atomic absorption spectrometer (ETAAS). Several parameters that could influence iCo microextraction and detection were carefully studied. Since the main difficulty in these samples is caused by high concentrations of potential interfering ions, different approaches were evaluated to eliminate interferences. The limit of detection (LOD) was 5.4 ng L{sup -1}, while the relative standard deviation (RSD) was 4.7% (at 0.5 {mu}g L{sup -1} Co level and n = 10), calculated from the peak height of absorbance signals. Selective microextraction of iCo species was achieved only by controlling the pH value during the procedure. The method was thus successfully applied for determination of iCo species in nutritional supplements.

  13. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... diagnose symptoms experienced by women such as: pelvic pain abnormal vaginal bleeding other menstrual problems Ultrasound exams ... pelvic ultrasound can help evaluate: pelvic masses pelvic pain ambiguous genitalia and anomalies of pelvic organs early ...

  14. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... size, shape and consistency (whether the object is solid or filled with fluid). In medicine, ultrasound is ... ultrasound, measures the direction and speed of blood cells as they move through vessels. The movement of ...

  15. Prostate Ultrasound

    Medline Plus

    Full Text Available ... pictures of a man’s prostate gland and to help diagnose symptoms such as difficulty urinating or an ... Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions. Prostate ultrasound, ...

  16. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... by women such as: pelvic pain abnormal vaginal bleeding other menstrual problems Ultrasound exams also help identify: ... fibroids cancer, especially in patients with abnormal uterine bleeding Some physicians also use 3-D ultrasound or ...

  17. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... internal organs, as well as blood flowing through blood vessels. Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions. There are three types of pelvic ultrasound: abdominal ( transabdominal ) vaginal ( transvaginal / endovaginal ) ...

  18. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... There are three types of pelvic ultrasound: abdominal, vaginal (for women), and rectal (for men). These exams ... are three types of pelvic ultrasound: abdominal ( transabdominal ) vaginal ( transvaginal / endovaginal ) for women rectal ( transrectal ) for men ...

  19. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... the procedure? In women, a pelvic ultrasound is most often performed to evaluate the: uterus cervix ovaries ... page How is the procedure performed? Transabdominal: For most ultrasound exams, you will be positioned lying face- ...

  20. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... is used to evaluate the: bladder seminal vesicles prostate Transrectal ultrasound, a special study usually done to provide detailed evaluation of the prostate gland, involves inserting a specialized ultrasound transducer into ...

  1. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... Obstetric Ultrasound Ultrasound - Prostate Kidney and Bladder Stones Abnormal Vaginal Bleeding ... questions or for a referral to a radiologist or other physician. To locate a medical imaging or radiation oncology provider in your community, you ...

  2. Prostate Ultrasound

    Medline Plus

    Full Text Available ... top of page What are the benefits vs. risks? Benefits Ultrasound is widely available, easy-to-use ... procedures such as needle biopsies and fluid aspiration. Risks For standard diagnostic ultrasound , there are no known ...

  3. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... insertion. top of page How does the procedure work? Ultrasound imaging is based on the same principles ... modality for the diagnosis and monitoring of pregnant women and their unborn babies. Ultrasound provides real-time ...

  4. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... ovarian cysts and uterine fibroids ovarian or uterine cancers A transvaginal ultrasound is usually performed to view the endometrium (the lining of the uterus) and the ovaries. Transvaginal ultrasound also evaluates the myometrium (muscular walls ...

  5. Prostate Ultrasound

    Medline Plus

    Full Text Available ... those sound waves to create an image. Ultrasound examinations do not use ionizing radiation (as used in ... abnormal masses, such as tumors. In an ultrasound examination, a transducer both sends the sound waves into ...

  6. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... needles are used to extract a sample of cells from organs for laboratory testing. Doppler ultrasound images ... ultrasound, measures the direction and speed of blood cells as they move through vessels. The movement of ...

  7. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... image. Ultrasound examinations do not use ionizing radiation (as used in x-rays ), thus there is no ... structure and movement of the body's internal organs, as well as blood flowing through blood vessels. Ultrasound ...

  8. Prostate Ultrasound

    Medline Plus

    Full Text Available ... to-use and less expensive than other imaging methods. Ultrasound imaging uses no ionizing radiation. Ultrasound scanning ... radiation oncology provider in your community, you can search the ACR-accredited facilities database . This website does ...

  9. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... Ultrasound is the preferred imaging modality for the diagnosis and monitoring of pregnant women and their unborn ... sexes without x-ray exposure. Risks For standard diagnostic ultrasound , there are no known harmful effects on ...

  10. Prostate Ultrasound

    Medline Plus

    Full Text Available ... patient. Because ultrasound images are captured in real-time, they can show the structure and movement of ... test result. difficulty urinating. Because ultrasound provides real-time images, it also can be used to guide ...

  11. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... patient. Because ultrasound images are captured in real-time, they can show the structure and movement of ... help to distract the child and make the time pass quickly. The ultrasound exam room may have ...

  12. Prostate Ultrasound

    Medline Plus

    Full Text Available ... Ultrasound provides real-time imaging, making it a good tool for guiding minimally invasive procedures such as ... bowel (rectum) removed during prior surgery are not good candidates for ultrasound of the prostate gland because ...

  13. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... Imaging? Ultrasound waves are disrupted by air or gas; therefore ultrasound is not an ideal imaging technique ... page Additional Information and Resources RTAnswers.org Radiation Therapy for Gynecologic Cancers Radiation Therapy for Prostate Cancer ...

  14. Prostate Ultrasound

    Medline Plus

    Full Text Available ... ultrasound images are captured in real-time, they can show the structure and movement of the body's ... Because ultrasound provides real-time images, it also can be used to guide procedures such as needle ...

  15. Prostate Ultrasound

    Medline Plus

    Full Text Available ... of page What will I experience during and after the procedure? Ultrasound exams in which the transducer ... in the sperm or urine following the procedure. After an ultrasound examination, you should be able to ...

  16. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... investigation of the uterine cavity . Three-dimensional (3-D) ultrasound permits evaluation of the uterus and ovaries ... abnormal uterine bleeding Some physicians also use 3-D ultrasound or sonohysterography for patients with infertility. In ...

  17. Prostate Ultrasound

    Medline Plus

    Full Text Available ... and produces pictures of the inside of the body using sound waves. Ultrasound imaging, also called ultrasound ... from the probe through the gel into the body. The transducer collects the sounds that bounce back ...

  18. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... and produces pictures of the inside of the body using sound waves. Ultrasound imaging, also called ultrasound ... from the probe through the gel into the body. The transducer collects the sounds that bounce back ...

  19. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... object is solid or filled with fluid). In medicine, ultrasound is used to detect changes in appearance, ... have special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media Sonohysterography Ultrasound - ...

  20. Obstetrical Ultrasound

    Science.gov (United States)

    ... heartbeat can be seen as an ongoing ultrasound movie. Ultrasound devices also use Doppler, a special application ... the possible charges you will incur. Web page review process: This Web page is reviewed regularly by ...

  1. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... insertion. top of page How does the procedure work? Ultrasound imaging is based on the same principles ... have special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media Sonohysterography Ultrasound - ...

  2. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... menstrual problems Ultrasound exams also help identify: palpable masses such as ovarian cysts and uterine fibroids ovarian ... In children, pelvic ultrasound can help evaluate: pelvic masses pelvic pain ambiguous genitalia and anomalies of pelvic ...

  3. Prostate Ultrasound

    Medline Plus

    Full Text Available ... Ultrasound is safe, noninvasive, and does not use ionizing radiation. This procedure requires little to no special preparation. ... create an image. Ultrasound examinations do not use ionizing radiation (as used in x-rays ), thus there is ...

  4. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... Ultrasound is safe, noninvasive and does not use ionizing radiation. This procedure requires little to no special preparation. ... create an image. Ultrasound examinations do not use ionizing radiation (as used in x-rays ), thus there is ...

  5. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... and development of an embryo or fetus during pregnancy. See the Obstetrical Ultrasound page for more information . ... object is solid or filled with fluid). In medicine, ultrasound is used to detect changes in appearance, ...

  6. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... most ultrasound exams, you will be positioned lying face-up on an examination table that can be ... region of the prostate. A biopsy will add time to the procedure. If a Doppler ultrasound study ...

  7. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... ultrasound: abdominal, vaginal (for women), and rectal (for men). These exams are frequently used to evaluate the ... vaginal ( transvaginal / endovaginal ) for women rectal ( transrectal ) for men A Doppler ultrasound exam may be part of ...

  8. Simple method for the determination of personal care product ingredients in lettuce by ultrasound-assisted extraction combined with solid-phase microextraction followed by GC-MS.

    Science.gov (United States)

    Cabrera-Peralta, Jerónimo; Peña-Alvarez, Araceli

    2018-05-01

    A simple method for the simultaneous determination of personal care product ingredients: galaxolide, tonalide, oxybenzone, 4-methylbenzyliden camphor, padimate-o, 2-ethylhexyl methoxycinnamate, octocrylene, triclosan, and methyl triclosan in lettuce by ultrasound-assisted extraction combined with solid-phase microextraction followed by gas chromatography with mass spectrometry was developed. Lettuce was directly extracted by ultrasound-assisted extraction with methanol, this extract was combined with water, extracted by solid-phase microextraction in immersion mode, and analyzed by gas chromatography with mass spectrometry. Good linear relationships (25-250 ng/g, R 2  > 0.9702) and low detection limits (1.0-25 ng/g) were obtained for analytes along with acceptable precision for almost all analytes (RSDs < 20%). The validated method was applied for the determination of personal care product ingredients in commercial lettuce and lettuces grown in soil and irrigated with the analytes, identifying the target analytes in leaves and roots of the latter. This procedure is a miniaturized and environmentally friendly proposal which can be a useful tool for quality analysis in lettuce. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... transducer sends out high-frequency sound waves (that the human ear cannot hear) into the body and then ... ultrasound , there are no known harmful effects on humans. top of page What are the limitations of Pelvic Ultrasound Imaging? Ultrasound waves are ...

  10. Cavitation-enhanced MR-guided focused ultrasound ablation of rabbit tumors in vivo using phase shift nanoemulsions

    OpenAIRE

    Kopechek, Jonathan A; Park, Eun-Joo; Zhang, Yong-Zhi; Vykhodtseva, Natalia I; McDannold, Nathan J; Porter, Tyrone M

    2014-01-01

    Advanced tumors are often inoperable due to their size and proximity to critical vascular structures. High intensity focused ultrasound (HIFU) has been developed to non-invasively thermally ablate inoperable solid tumors. However, the clinical feasibility of HIFU ablation therapy has been limited by the long treatment times (on the order of hours) and high acoustic intensities required. Studies have shown that inertial cavitation can enhance HIFU-mediated heating by generating broadband acous...

  11. On the evaluation of temperature dependence of elastic constants of martensitic phases in shape memory alloys from resonant ultrasound spectroscopy studies

    International Nuclear Information System (INIS)

    Landa, Michal; Sedlak, Petr; Sittner, Petr; Seiner, Hanus; Heller, Ludek

    2008-01-01

    Elastic constants of austenite and martensite phases in shape memory alloys reflect fundamental thermodynamic properties of these materials-i.e. important physical information can be deduced not just from the values of the constants but, mainly from their temperature and stress dependencies. As regards to the parent austenite phase, such information is available in the literature for most of the known shape memory alloys. For the martensitic phases, however, only few reliable experimental data exist, due to the experimental difficulties with the preparation of martensite single crystals as well as due to the difficulties with the ultrasonic measurement of elastic properties of strongly anisotropic media with low symmetry. In this work, the temperature dependence of all elastic constants of cubic austenite and orthorhombic 2H martensite phases in Cu-Al-Ni alloy determined by resonance ultrasound spectroscopy (RUS) is reported. Experimental and theoretical improvements of the RUS method which had to be made to perform the successful measurements on strongly anisotropic and martensitic phases are discussed

  12. Radioactive fallout in the southern hemisphere from nuclear weapons tests

    International Nuclear Information System (INIS)

    Moroney, J.R.

    1979-11-01

    Fallout in the southern hemisphere, and its origins in the national programs of atmospheric nuclear weapons testing in both hemispheres, are reviewed. Of the 390 nuclear tests conducted in the atmosphere to date, 53 were carried out in the southern hemisphere and it is the second phase of these, between 1966 and 1974, that is seen to have been responsible for the main fallout of short-lived fission products in the southern hemisphere. In contrast to this, the programs of atmospheric nuclear testing in the northern hemisphere up to 1962 are shown to have been the main source of long-lived fission products in fallout in the southern hemisphere. The course followed by this contamination through the environment of the southern hemisphere is traced for the national programs of nuclear testing after 1962 taken separately (France, China) and for the earlier national programs taken together (U.S.S.R., U.S.A. and U.K.). The impact on populations in the southern hemisphere of fallout from atmospheric nuclear weapons tests to date is assessed

  13. Radioactive fallout in the southern hemisphere from nuclear weapons tests

    International Nuclear Information System (INIS)

    Moroney, J.R.

    1979-01-01

    Fallout in the southern hemisphere, and its origins in the national programs of atmospheric nuclear weapons testing in both hemispheres, are reviewed. Of the 390 nuclear tests conducted in the atmosphere to date, 53 were carried out in the southern hemisphere and it is the second phase of these, between 1966 and 1974, that is seen to have been responsible for the main fallout of short-lived fission products in the southern hemisphere. In contrast to this, the programs of atmospheric nuclear testing in the northern hemisphere up to 1962 are shown to have been the main source of long-lived fission products in fallout in the southern hemisphere. The course followed by this contamination through the environment of the southern hemisphere is traced for the national programs of nuclear testing after 1962 taken separately (France, China) and for the earlier national programs taken together (U.S.S.R., U.S.A. and U.K.). The impact on populations in the southern hemisphere of fallout from atmospheric nuclear weapons tests to date is assessed. (author)

  14. Pre-clinical testing of a phased array ultrasound system for MRI-guided noninvasive surgery of the brain--a primate study.

    Science.gov (United States)

    Hynynen, Kullervo; McDannold, Nathan; Clement, Greg; Jolesz, Ferenc A; Zadicario, Eyal; Killiany, Ron; Moore, Tara; Rosen, Douglas

    2006-08-01

    MRI-guided and monitored focused ultrasound thermal surgery of brain through intact skull was tested in three rhesus monkeys. The aim of this study was to determine the amount of skull heating in an animal model with a head shape similar to that of a human. The ultrasound beam was generated by a 512 channel phased array system (Exablate 3000, InSightec, Haifa, Israel) that was integrated within a 1.5-T MR-scanner. The skin was pre-cooled by degassed temperature controlled water circulating between the array surface and the skin. Skull surface temperature was measured with invasive thermocouple probes. The results showed that by applying surface cooling the skin and skull surface can be protected, and that the brain surface temperature becomes the limiting factor. The MRI thermometry was shown to be useful in detecting the tissue temperature distribution next to the bone, and it should be used to monitor the brain surface temperature. The acoustic intensity values during the 20 s sonications were adequate for thermal ablation in the human brain provided that surface cooling is used.

  15. Contrast-enhanced ultrasound imaging and in vivo circulatory kinetics with low-boiling-point nanoscale phase-change perfluorocarbon agents.

    Science.gov (United States)

    Sheeran, Paul S; Rojas, Juan D; Puett, Connor; Hjelmquist, Jordan; Arena, Christopher B; Dayton, Paul A

    2015-03-01

    Many studies have explored phase-change contrast agents (PCCAs) that can be vaporized by an ultrasonic pulse to form microbubbles for ultrasound imaging and therapy. However, few investigations have been published on the utility and characteristics of PCCAs as contrast agents in vivo. In this study, we examine the properties of low-boiling-point nanoscale PCCAs evaluated in vivo and compare data with those for conventional microbubbles with respect to contrast generation and circulation properties. To do this, we develop a custom pulse sequence to vaporize and image PCCAs using the Verasonics research platform and a clinical array transducer. Results indicate that droplets can produce contrast enhancement similar to that of microbubbles (7.29 to 18.24 dB over baseline, depending on formulation) and can be designed to circulate for as much as 3.3 times longer than microbubbles. This study also reports for the first time the ability to capture contrast washout kinetics of the target organ as a measure of vascular perfusion. Copyright © 2015 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  16. High power phased array prototype for clinical high intensity focused ultrasound : applications to transcostal and transcranial therapy.

    Science.gov (United States)

    Pernot, M; Aubry, J -F; Tanter, M; Marquet, F; Montaldo, G; Boch, A -L; Kujas, M; Seilhean, D; Fink, M

    2007-01-01

    Bursts of focused ultrasound energy three orders of magnitude more intense than diagnostic ultrasound became during the last decade a noninvasive option for treating cancer from breast to prostate or uterine fibroid. However, many challenges remain to be addressed. First, the corrections of distortions induced on the ultrasonic therapy beam during its propagation through defocusing obstacles like skull bone or ribs remain today a technological performance that still need to be validated clinically. Secondly, the problem of motion artifacts particularly important for the treatment of abdominal parts becomes today an important research topic. Finally, the problem of the treatment monitoring is a wide subject of interest in the growing HIFU community. For all these issues, the potential of new ultrasonic therapy devices able to work both in Transmit and Receive modes will be emphasized. A review of the work under achievement at L.O.A. using this new generation of HIFU prototypes on the monitoring, motion correction and aberrations corrections will be presented.

  17. Optimization of ultrasound-assisted aqueous two-phase system extraction of polyphenolic compounds from Aronia melanocarpa pomace by response surface methodology.

    Science.gov (United States)

    Xu, Yan-Yang; Qiu, Yang; Ren, Hui; Ju, Dong-Hu; Jia, Hong-Lei

    2017-03-16

    Aronia melanocarpa berries are abundant in polyphenolic compounds. After juice production, the pomace of pressed berries still contains a substantial amount of polyphenolic compounds. For efficient utilization of A. melanocarpa berries and the enhancement of polyphenolic compound yields in Aronia melanocarpa pomace (AMP), total phenolics (TP) and total flavonoids (TF) from AMP were extracted, using ultrasound-assisted aqueous two-phase system (UAE-ATPS) extraction method. First, the influences of ammonium sulfate concentration, ethanol-water ratio, ultrasonic time, and ultrasonic power on TP and TF yields were investigated. On this basis, process variables such as ammonium sulfate concentration (0.30-0.35 g mL -1 ), ethanol-water ratio (0.6-0.8), ultrasonic time (40-60 min), and ultrasonic power (175-225 W) were further optimized by implementing Box-Benhnken design with response surface methodology. The experimental results showed that optimal extraction conditions of TP from AMP were as follows: ammonium sulfate concentration of 0.324 g mL -1 , ethanol-water ratio of 0.69, ultrasonic time of 52 min, and ultrasonic power of 200 W. Meanwhile, ammonium sulfate concentration of 0.320 g mL -1 , ethanol-water ratio of 0.71, ultrasonic time of 50 min, and ultrasonic power of 200 W were determined as optimum extraction conditions of TF in AMP. Experimental validation was performed, where TP and TF yields reached 68.15 ± 1.04 and 11.67 ± 0.63 mg g -1 , respectively. Close agreement was found between experimental and predicted values. Overall, the present results demonstrated that ultrasound-assisted aqueous two-phase system extraction method was successfully used to extract total phenolics and flavonoids in A. melanocarpa pomace.

  18. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... internal organs, as well as blood flowing through blood vessels. Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions. ...

  19. Detonation in TATB Hemispheres

    Energy Technology Data Exchange (ETDEWEB)

    Druce, B; Souers, P C; Chow, C; Roeske, F; Vitello, P; Hrousis, C

    2004-03-17

    Streak camera breakout and Fabry-Perot interferometer data have been taken on the outer surface of 1.80 g/cm{sup 3} TATB hemispherical boosters initiated by slapper detonators at three temperatures. The slapper causes breakout to occur at 54{sup o} at ambient temperatures and 42{sup o} at -54 C, where the axis of rotation is 0{sup o}. The Fabry velocities may be associated with pressures, and these decrease for large timing delays in breakout seen at the colder temperatures. At room temperature, the Fabry pressures appear constant at all angles. Both fresh and decade-old explosive are tested and no difference is seen. The problem has been modeled with reactive flow. Adjustment of the JWL for temperature makes little difference, but cooling to -54 C decreases the rate constant by 1/6th. The problem was run both at constant density and with density differences using two different codes. The ambient code results show that a density difference is probably there but it cannot be quantified.

  20. Detonation in TATB hemispheres

    Energy Technology Data Exchange (ETDEWEB)

    Druce, Robert L.; Souers, P. Clark; Chow, Charles; Roeske, Franklin; Vitello, Peter; Hrousis, Constantine [Lawrence Livermore National Laboratory, Livermore, CA, 94550 (United States)

    2005-04-01

    Streak camera breakout and Fabry-Perot interferometer data have been taken on the outer surface of 1.80 g/cm{sup 3} TATB (triamino-trinitrobenzene) hemispherical boosters initiated by slapper detonators at three temperatures. The slapper causes breakout to occur at 54 at ambient temperatures and 42 at -54 C, where the axis of rotation is 0 . The Fabry velocities may be associated with pressures, and these decrease for large timing delays in breakout seen at the colder temperatures. At room temperature, the Fabry pressures appear constant at all angles. Both fresh and decade-old explosive are tested and no difference is seen. The problem has been modeled with reactive flow. Adjustment of the JWL for temperature makes little difference, but cooling to -54 C decreases the rate constant by 1/6th. The problem was run both at constant density and with density differences using two different codes. The ambient code results show that a density difference is probably present, but it cannot be quantified. (Abstract Copyright [2005], Wiley Periodicals, Inc.)

  1. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... inserted into a man's rectum to view the prostate. Transvaginal ultrasound. The transducer is inserted into a ... Stenting Ultrasound-Guided Breast Biopsy Obstetric Ultrasound Ultrasound - Prostate Biopsies - Overview Images related to General Ultrasound Videos ...

  2. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z General Ultrasound Ultrasound imaging uses sound waves to produce ... the limitations of General Ultrasound Imaging? What is General Ultrasound Imaging? Ultrasound is safe and painless, and ...

  3. Prostate Ultrasound

    Medline Plus

    Full Text Available ... be able to give a clearer picture of soft tissues that do not show up well on x-ray images. Ultrasound causes no health problems and may be repeated as often as is necessary if medically indicated. Ultrasound provides real-time imaging, making it a good tool for guiding ...

  4. Prostate Ultrasound

    Science.gov (United States)

    ... be able to give a clearer picture of soft tissues that do not show up well on x-ray images. Ultrasound causes no health problems and may be repeated as often as is necessary if medically indicated. Ultrasound provides real-time imaging, making it a good tool for guiding ...

  5. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Ultrasound - Pelvis Ultrasound imaging of the pelvis uses sound waves to ...

  6. Interventional ultrasound

    International Nuclear Information System (INIS)

    VanSonnenberg, E.

    1987-01-01

    This book contains 12 chapters and several case studies. Some of the chapter titles are: The Interplay of Ultrasound and Computed Tomography in the Planning and Execution of Interventional Procedures: Ulltrasound Guided Biopsy; Interventioal Genitourinary Sonography; Diagnosis and Treatment of Pericardial Effusion Using Ultrasonic Guidance; and New Ultrasound-Guided Interventional Procedures--Cholecystostomy, Pancreatography, Gastrostomy

  7. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Ultrasound - Pelvis Ultrasound imaging ...

  8. Prostate Ultrasound

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Ultrasound - Prostate Ultrasound of ...

  9. Ultrasound stethoscopy

    NARCIS (Netherlands)

    E.C. Vourvouri (Eleni)

    2002-01-01

    textabstractIn this thesis we repmi the many evaluation studies with the hand-held ultrasound device in the assessment of different cardiac pathologies and in different clinical settings. The reason for using the tetm "ultrasound stethoscopy" is that these devices are augmenting our

  10. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... to-use and less expensive than other imaging methods. Ultrasound imaging is extremely safe and does not use any ionizing radiation. Ultrasound scanning gives a clear picture of soft tissues that do not show up well on ...

  11. Prostate Ultrasound

    Medline Plus

    Full Text Available ... the best way to see if treatment is working or if a finding is stable or changed over time. top of page What are the benefits vs. risks? Benefits Ultrasound is widely available, easy-to-use and less expensive than other imaging methods. Ultrasound imaging uses ...

  12. Prostate Ultrasound

    Medline Plus

    Full Text Available ... the patient. Because ultrasound images are captured in real-time, they can show the structure and movement of ... blood test result. difficulty urinating. Because ultrasound provides real-time images, it also can be used to guide ...

  13. Reliability considerations of NDT by probability of detection (POD). Determination using ultrasound phased array. Results from a project in frame of the German nuclear safety research program

    International Nuclear Information System (INIS)

    Kurz, Jochen H.; Dugan, Sandra; Juengert, Anne

    2013-01-01

    Reliable assessment procedures are an important aspect of maintenance concepts. Non-destructive testing (NDT) methods are an essential part of a variety of maintenance plans. Fracture mechanical assessments require knowledge of flaw dimensions, loads and material parameters. NDT methods are able to acquire information on all of these areas. However, it has to be considered that the level of detail information depends on the case investigated and therefore on the applicable methods. Reliability aspects of NDT methods are of importance if quantitative information is required. Different design concepts e.g. the damage tolerance approach in aerospace already include reliability criteria of NDT methods applied in maintenance plans. NDT is also an essential part during construction and maintenance of nuclear power plants. In Germany, type and extent of inspection are specified in Safety Standards of the Nuclear Safety Standards Commission (KTA). Only certified inspections are allowed in the nuclear industry. The qualification of NDT is carried out in form of performance demonstrations of the inspection teams and the equipment, witnessed by an authorized inspector. The results of these tests are mainly statements regarding the detection capabilities of certain artificial flaws. In other countries, e.g. the U.S., additional blind tests on test blocks with hidden and unknown flaws may be required, in which a certain percentage of these flaws has to be detected. The knowledge of the probability of detection (POD) curves of specific flaws in specific testing conditions is often not present. This paper shows the results of a research project designed for POD determination of ultrasound phased array inspections of real and artificial cracks. The continuative objective of this project was to generate quantitative POD results. The distribution of the crack sizes of the specimens and the inspection planning is discussed, and results of the ultrasound inspections are presented. In

  14. A random phased-array for MR-guided transcranial ultrasound neuromodulation in non-human primates.

    Science.gov (United States)

    Chaplin, Vandiver; Phipps, Marshal A; Caskey, Charles F

    2018-04-18

    Transcranial focused ultrasound (FUS) is a non-invasive technique for therapy and study of brain neural activation. Here we report on the design and characterization of a new MR-guided FUS transducer for neuromodulation in non-human primates at 650 kHz. The array is randomized with 128 elements 6.6 mm in diameter, radius of curvature 7.2 cm, opening diameter 10.3 cm (focal ratio 0.7), and 46% coverage. Simulations were used to optimize transducer geometry with respect to focus size, grating lobes, and directivity. Focus size and grating lobes during electronic steering were quantified using hydrophone measurements in water and a three-axis stage. A novel combination of optical tracking and acoustic mapping enabled measurement of the 3D pressure distribution in the cortical region of an ex vivo skull to within ~3.5 mm of the surface, and allowed accurate modelling of the experiment via non-homogeneous 3D acoustic simulations. The data demonstrates acoustic focusing beyond the skull bone, with the focus slightly broadened and shifted proximal to the skull. The fabricated design is capable of targeting regions within the S1 sensorimotor cortex of macaques. © 2018 Institute of Physics and Engineering in Medicine.

  15. A random phased-array for MR-guided transcranial ultrasound neuromodulation in non-human primates

    Science.gov (United States)

    Chaplin, Vandiver; Phipps, Marshal A.; Caskey, Charles F.

    2018-05-01

    Transcranial focused ultrasound (FUS) is a non-invasive technique for therapy and study of brain neural activation. Here we report on the design and characterization of a new MR-guided FUS transducer for neuromodulation in non-human primates at 650 kHz. The array is randomized with 128 elements 6.6 mm in diameter, radius of curvature 7.2 cm, opening diameter 10.3 cm (focal ratio 0.7), and 46% coverage. Simulations were used to optimize transducer geometry with respect to focus size, grating lobes, and directivity. Focus size and grating lobes during electronic steering were quantified using hydrophone measurements in water and a three-axis stage. A novel combination of optical tracking and acoustic mapping enabled measurement of the 3D pressure distribution in the cortical region of an ex vivo skull to within ~3.5 mm of the surface, and allowed accurate modelling of the experiment via non-homogeneous 3D acoustic simulations. The data demonstrates acoustic focusing beyond the skull bone, with the focus slightly broadened and shifted proximal to the skull. The fabricated design is capable of targeting regions within the S1 sensorimotor cortex of macaques.

  16. Rapid ultrasound-induced transient-liquid-phase bonding of Al-50Si alloys with Zn interlayer in air for electrical packaging application.

    Science.gov (United States)

    Wang, Qian; Chen, Xiaoguang; Zhu, Lin; Yan, Jiuchun; Lai, Zhiwei; Zhao, Pizhi; Bao, Juncheng; Lv, Guicai; You, Chen; Zhou, Xiaoyu; Zhang, Jian; Li, Yuntao

    2017-01-01

    Al-50Si alloys were joined by rapid ultrasound-induced transient-liquid-phase bonding method using Zn foil as interlayer at 390°C in air, below the melt point of interlayer. The fracture of oxide films along the edge of Si particles led to contact and inter-diffusion between aluminum substrate and Zn interlayer, and liquefied Zn-Al alloys were developed. The width of Zn-Al alloys gradually decreased with increasing the ultrasonic vibration time due to liquid squeezing out and accelerated diffusion. A stage of isothermal solidification existed, and the completion time was significantly shortened. In the liquid metal, the acoustic streaming and ultrasonic cavitations were induced. As the process developed, much more Si particles, which were particulate-reinforced phases of Al-50Si, gradually migrated to the center of soldering seam. The highest average shear strength of joints reached to 94.2MPa, and the fracture mainly occurred at the base metal. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Magnetic phase diagram of Ba3CoSb2O9 as determined by ultrasound velocity measurements

    Science.gov (United States)

    Quirion, G.; Lapointe-Major, M.; Poirier, M.; Quilliam, J. A.; Dun, Z. L.; Zhou, H. D.

    2015-07-01

    Using high-resolution sound velocity measurements we have obtained a very precise magnetic phase diagram of Ba3CoSb2O9 , a material that is considered to be an archetype of the spin-1/2 triangular-lattice antiferromagnet. Results obtained for the field parallel to the basal plane (up to 18 T) show three phase transitions, consistent with predictions based on simple two-dimensional isotropic Heisenberg models and previous experimental investigations. The phase diagram obtained for the field perpendicular to the basal plane clearly reveals an easy-plane character of this compound and, in particular, our measurements show a single first-order phase transition at Hc 1=12.0 T which can be attributed to a spin flop between an umbrella-type configuration and a coplanar V -type order where spins lie in a plane perpendicular to the a b plane. At low temperatures, softening of the lattice within some of the ordered phases is also observed and may be a result of residual spin fluctuations.

  18. Western Hemisphere Knowledge Partnerships

    Science.gov (United States)

    Malone, T. F.

    2001-05-01

    , and application of knowledge concerning the nature of -- and interaction among -- matter, living organisms, energy, information, and human behavior. This strategy calls for innovative partnerships among the physical, biological, health, and social sciences, engineering, and the humanities. New kinds of partnership must also be forged among academia, business and industry, governments, and nongovernmental organizations. Geophysicists can play an important role in these partnerships. A focus for these partnerships is to manage the individual economic productivity that drives both human development and global change. As world population approaches stability during the twenty-first century, individual economic productivity will be the critical link between the human and the natural systems on planet Earth. AGU is among a core group of individuals and institutions proposing Western Hemisphere Knowledge Partnerships (WHKP) to test the hypothesis that knowledge, broadly construed, is an important organizing principle in choosing a path into the future. The WHKP agenda includes: (1) life-long learning, (2) the health and resilience of natural ecosystems, (3) eco-efficiency in economic production and consumption, (4) extension of national income accounts, (5) environmentally benign sources of energy, (6) delivery of health care, (7) intellectual property rights, and (8) networks for action by local communities.Collaboratories and distance education technologies will be major tools. A panel of experts will explore this proposal.

  19. Fetal Ultrasound

    Science.gov (United States)

    ... isn't recommended simply to determine a baby's sex. Similarly, fetal ultrasound isn't recommended solely for the purpose of producing keepsake videos or pictures. If your health care provider doesn' ...

  20. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... and movement of the body's internal organs, as well as blood flowing through blood vessels. Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions. ...

  1. Prostate Ultrasound

    Medline Plus

    Full Text Available ... and movement of the body's internal organs, as well as blood flowing through blood vessels. Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions. ...

  2. Prostate Ultrasound

    Medline Plus

    Full Text Available ... nodule felt by a physician during a routine physical exam or prostate cancer screening exam. an elevated blood test result. difficulty urinating. Because ultrasound provides real-time ...

  3. Prostate Ultrasound

    Medline Plus

    Full Text Available ... requested the exam. Usually, the referring physician or health care provider will share the results with you. ... well on x-ray images. Ultrasound causes no health problems and may be repeated as often as ...

  4. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... ultrasound exams are also used to monitor the health and development of an embryo or fetus during ... requested the exam. Usually, the referring physician or health care provider will share the results with you. ...

  5. Prostate Ultrasound

    Medline Plus

    Full Text Available ... probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the ... the transducer (the device placed on the patient's skin to send and receive the returning sound waves), ...

  6. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the ... the transducer (the device placed on the patient's skin to send and receive the returning sound waves), ...

  7. Prostate Ultrasound

    Medline Plus

    Full Text Available ... no ionizing radiation. Ultrasound scanning may be able to give a clearer picture of soft tissues that do ... understanding of the possible charges you will incur. Web page review process: This Web page is reviewed ...

  8. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... use different transducers (with different capabilities) during a single exam. The transducer sends out high-frequency sound ... modality for the diagnosis and monitoring of pregnant women and their unborn babies. Ultrasound provides real-time ...

  9. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... collects the sounds that bounce back and a computer then uses those sound waves to create an ... Ultrasound scanners consist of a console containing a computer and electronics, a video display screen and a ...

  10. Prostate Ultrasound

    Medline Plus

    Full Text Available ... collects the sounds that bounce back and a computer then uses those sound waves to create an ... Ultrasound scanners consist of a console containing a computer and electronics, a video display screen and a ...

  11. Prostate Ultrasound

    Medline Plus

    Full Text Available ... sends out high-frequency sound waves (that the human ear cannot hear) into the body and then ... ultrasound , there are no known harmful effects on humans. top of page What are the limitations of ...

  12. Prostate Ultrasound

    Medline Plus

    Full Text Available ... is located directly in front of the rectum, so the ultrasound exam is performed transrectally in order ... A follow-up examination may also be necessary so that any change in a known abnormality can ...

  13. Prostate Ultrasound

    Medline Plus

    Full Text Available ... the rectal wall is relatively insensitive to the pain in the region of the prostate. A biopsy ... needle biopsies and fluid aspiration. Risks For standard diagnostic ultrasound , there are no known harmful effects on ...

  14. Prostate Ultrasound

    Medline Plus

    Full Text Available ... diagnose symptoms such as difficulty urinating or an elevated blood test result. It’s also used to investigate ... physical exam or prostate cancer screening exam. an elevated blood test result. difficulty urinating. Because ultrasound provides ...

  15. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... The principles are similar to sonar used by boats and submarines. The ultrasound image is immediately visible ... principles involved in the sonar used by bats, ships and fishermen. When a sound wave strikes an ...

  16. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... areas of the body while other areas, especially air-filled lungs, are poorly suited for ultrasound. For ... make secure contact with the body and eliminate air pockets between the transducer and the skin that ...

  17. Prostate Ultrasound

    Medline Plus

    Full Text Available ... a follow-up exam is done because a potential abnormality needs further evaluation with additional views or ... of soft tissues that do not show up well on x-ray images. Ultrasound causes no health ...

  18. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... a follow-up exam is done because a potential abnormality needs further evaluation with additional views or ... of soft tissues that do not show up well on x-ray images. Ultrasound is the preferred ...

  19. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... is smaller than the standard speculum used when performing a Pap test . A protective cover is placed ... of soft tissues that do not show up well on x-ray images. Ultrasound is the preferred ...

  20. Prostate Ultrasound

    Medline Plus

    Full Text Available ... scanning or sonography , involves the use of a small transducer (probe) and ultrasound gel placed directly on ... to do the scanning. The transducer is a small hand-held device that resembles a microphone, attached ...

  1. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... scanning or sonography , involves the use of a small transducer (probe) and ultrasound gel placed directly on ... the child prior to the exam. Bringing books, small toys, music or games can help to distract ...

  2. Prostate Ultrasound

    Medline Plus

    Full Text Available ... less than 20 minutes. top of page What will I experience during and after the procedure? Ultrasound ... in the region of the prostate. A biopsy will add time to the procedure. Rarely, a small ...

  3. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... ultrasound images are reviewed. top of page What will I experience during and after the procedure? For ... in the region of the prostate. A biopsy will add time to the procedure. If a Doppler ...

  4. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... arteries and veins in the abdomen, arms, legs, neck and/or brain (in infants and children) or ... diagnose symptoms experienced by women such as: pelvic pain abnormal vaginal bleeding other menstrual problems Ultrasound exams ...

  5. Prostate Ultrasound

    Medline Plus

    Full Text Available ... gel. top of page How does the procedure work? Ultrasound imaging is based on the same principles ... the best way to see if treatment is working or if a finding is stable or changed ...

  6. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... and development of an embryo or fetus during pregnancy. See the Obstetrical Ultrasound page for more information . ... move through vessels. The movement of blood cells causes a change in pitch of the reflected sound ...

  7. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... abdomen, arms, legs, neck and/or brain (in infants and children) or within various body organs such ... and monitoring of pregnant women and their unborn babies. Ultrasound provides real-time imaging, making it a ...

  8. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... to-use and less expensive than other imaging methods. Ultrasound imaging is extremely safe and does not ... barium exams, CT scanning , and MRI are the methods of choice in such a setting. Large patients ...

  9. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... insertion. top of page How does the procedure work? Ultrasound imaging is based on the same principles ... move through vessels. The movement of blood cells causes a change in pitch of the reflected sound ...

  10. Prostate Ultrasound

    Medline Plus

    Full Text Available ... gel. top of page How does the procedure work? Ultrasound imaging is based on the same principles ... requested the exam. Usually, the referring physician or health care provider will share the results with you. ...

  11. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... insertion. top of page How does the procedure work? Ultrasound imaging is based on the same principles ... requested the exam. Usually, the referring physician or health care provider will share the results with you. ...

  12. Ultrasound imaging

    International Nuclear Information System (INIS)

    Wells, P.N.T.

    1983-01-01

    Ultrasound is a form of energy which consists of mechanical vibrations the frequencies of which are so high that they are above the range of human hearing. The lower frequency limit of the ultrasonic spectrum may generally be taken to be about 20 kHz. Most biomedical applications of ultrasound employ frequencies in the range 1-15 MHz. At these frequencies, the wavelength is in the range 1.5 - 0.1 mm in soft tissues, and narrow beams of ultrasound can be generated which propagate through such tissues without excessive attenuation. This chapter begins with brief reviews of the physics of diagnostic ultrasound pulse-echo imaging methods and Doppler imaging methods. The remainder of the chapter is a resume of the applications of ultrasonic imaging to physiological measurement

  13. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... be necessary. Your doctor will explain the exact reason why another exam is requested. Sometimes a follow- ... Ultrasound provides real-time imaging, making it a good tool for guiding minimally invasive procedures such as ...

  14. Prostate Ultrasound

    Medline Plus

    Full Text Available ... be necessary. Your doctor will explain the exact reason why another exam is requested. Sometimes a follow- ... Ultrasound provides real-time imaging, making it a good tool for guiding minimally invasive procedures such as ...

  15. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... frequently used to evaluate the reproductive and urinary systems. Ultrasound is safe, noninvasive and does not use ... and evaluate a variety of urinary and reproductive system disorders in both sexes without x-ray exposure. ...

  16. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... be asked to drink water prior to the examination to fill your bladder. Leave jewelry at home ... those sound waves to create an image. Ultrasound examinations do not use ionizing radiation (as used in ...

  17. Prostate Ultrasound

    Medline Plus

    Full Text Available ... top of page Additional Information and Resources RTAnswers.org Radiation Therapy for Prostate Cancer top of page ... to Ultrasound - Prostate Sponsored by Please note RadiologyInfo.org is not a medical facility. Please contact your ...

  18. Prostate Ultrasound

    Medline Plus

    Full Text Available ... with measurements acquired as needed for any treatment planning. detect an abnormal growth within the prostate. help ... end of their bowel (rectum) removed during prior surgery are not good candidates for ultrasound of the ...

  19. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... tip of the transducer is smaller than the standard speculum used when performing a Pap test . A ... both sexes without x-ray exposure. Risks For standard diagnostic ultrasound , there are no known harmful effects ...

  20. Prostate Ultrasound

    Medline Plus

    Full Text Available ... prostate gland and to help diagnose symptoms such as difficulty urinating or an elevated blood test result. ... image. Ultrasound examinations do not use ionizing radiation (as used in x-rays ), thus there is no ...

  1. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... in the abdomen, arms, legs, neck and/or brain (in infants and children) or within various body organs ... or uterine cancers A transvaginal ultrasound is usually performed to view ...

  2. Prostate Ultrasound

    Medline Plus

    Full Text Available ... is enlarged, also known as benign prostatic hyperplasia (BPH) , with measurements acquired as needed for any treatment ... caption Related Articles and Media Benign Prostatic Hyperplasia (BPH) (Enlargement of the Prostate) Prostate Cancer Ultrasound- and ...

  3. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... the exam. Bringing books, small toys, music or games can help to distract the child and make ... modality for the diagnosis and monitoring of pregnant women and their unborn babies. Ultrasound provides real-time ...

  4. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... uterine cavity . Three-dimensional (3-D) ultrasound permits evaluation of the uterus and ovaries in planes that ... a special study usually done to provide detailed evaluation of the prostate gland, involves inserting a specialized ...

  5. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... the examination process. To ensure a smooth experience, it often helps to explain the procedure to the ... on the amplitude (loudness), frequency (pitch) and time it takes for the ultrasound signal to return from ...

  6. Prostate Ultrasound

    Medline Plus

    Full Text Available ... difficulty urinating or an elevated blood test result. It’s also used to investigate a nodule found during ... difficulty urinating. Because ultrasound provides real-time images, it also can be used to guide procedures such ...

  7. Prostate Ultrasound

    Medline Plus

    Full Text Available ... needle biopsies and fluid aspiration. Risks For standard diagnostic ultrasound , there are no known harmful effects on ... and Resources RTAnswers.org Radiation Therapy for Prostate Cancer top of page This page was reviewed on ...

  8. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... sexes without x-ray exposure. Risks For standard diagnostic ultrasound , there are no known harmful effects on ... and Resources RTAnswers.org Radiation Therapy for Gynecologic Cancers Radiation Therapy for Prostate Cancer top of page ...

  9. Prostate Ultrasound

    Medline Plus

    Full Text Available ... rectum. top of page What are some common uses of the procedure? A transrectal ultrasound of the ... is done because a potential abnormality needs further evaluation with additional views or a special imaging technique. ...

  10. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... legs, neck and/or brain (in infants and children) or within various body organs such as the ... tumors other disorders of the urinary bladder In children, pelvic ultrasound can help evaluate: pelvic masses pelvic ...

  11. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... uterus). Sonohysterography allows for a more in-depth investigation of the uterine cavity . Three-dimensional (3-D) ... to-use and less expensive than other imaging methods. Ultrasound imaging is extremely safe and does not ...

  12. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... is Pelvic Ultrasound Imaging? What are some common uses of the procedure? How should I prepare? What does the equipment look like? How does the procedure work? How is the procedure performed? What will I ...

  13. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... quickly. The ultrasound exam room may have a television. Feel free to ask for your child's favorite ... display screen that looks like a computer or television monitor. The image is created based on the ...

  14. Prostate Ultrasound

    Medline Plus

    Full Text Available ... Images related to Ultrasound - Prostate Sponsored by Please note RadiologyInfo.org is not a medical facility. Please ... is further reviewed by committees from the American College of Radiology (ACR) and the Radiological Society of ...

  15. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... Images related to Ultrasound - Pelvis Sponsored by Please note RadiologyInfo.org is not a medical facility. Please ... is further reviewed by committees from the American College of Radiology (ACR) and the Radiological Society of ...

  16. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... symptoms experienced by women such as: pelvic pain abnormal vaginal bleeding other menstrual problems Ultrasound exams also ... endometrial polyps fibroids cancer, especially in patients with abnormal uterine bleeding Some physicians also use 3-D ...

  17. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... The ultrasound exam room may have a television. Feel free to ask for your child's favorite channel. ... performed over an area of tenderness, you may feel pressure or minor pain from the transducer. Once ...

  18. Prostate Ultrasound

    Medline Plus

    Full Text Available ... also known as benign prostatic hyperplasia (BPH) , with measurements acquired as needed for any treatment planning. detect ... areas of the body while other areas, especially air-filled lungs, are poorly suited for ultrasound. For ...

  19. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... ovarian cysts and uterine fibroids ovarian or uterine cancers A transvaginal ultrasound is usually performed to view ... detect: uterine anomalies uterine scars endometrial polyps fibroids cancer, especially in patients with abnormal uterine bleeding Some ...

  20. Prostate Ultrasound

    Medline Plus

    Full Text Available ... rectum. top of page What are some common uses of the procedure? A transrectal ultrasound of the ... community, you can search the ACR-accredited facilities database . This website does not provide cost information. The ...

  1. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... kidneys. top of page What are some common uses of the procedure? In women, a pelvic ultrasound ... community, you can search the ACR-accredited facilities database . This website does not provide cost information. The ...

  2. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... of the reflected sound waves (called the Doppler effect). A computer collects and processes the sounds and ... standard diagnostic ultrasound , there are no known harmful effects on humans. top of page What are the ...

  3. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... sends out high-frequency sound waves (that the human ear cannot hear) into the body and then ... ultrasound , there are no known harmful effects on humans. top of page What are the limitations of ...

  4. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... various body organs such as the liver or kidneys. top of page What are some common uses ... women, a pelvic ultrasound exam can help identify: kidney stones bladder tumors other disorders of the urinary ...

  5. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... the ovaries. Transvaginal ultrasound also evaluates the myometrium (muscular walls of the uterus). Sonohysterography allows for a ... and evaluate a variety of urinary and reproductive system disorders in both sexes without x-ray exposure. ...

  6. Prostate Ultrasound

    Medline Plus

    Full Text Available ... echoes from the tissues in the body. The principles are similar to sonar used by boats and ... work? Ultrasound imaging is based on the same principles involved in the sonar used by bats, ships ...

  7. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... echoes from the tissues in the body. The principles are similar to sonar used by boats and ... work? Ultrasound imaging is based on the same principles involved in the sonar used by bats, ships ...

  8. Prostate Ultrasound

    Medline Plus

    Full Text Available ... is at high risk for cancer. In this case, a biopsy is performed and an ultrasound probe ... will share the results with you. In some cases, the radiologist may discuss results with you at ...

  9. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... ovaries. Transvaginal ultrasound also evaluates the myometrium (muscular walls of the uterus). Sonohysterography allows for a more ... needle insertion) is usually minimal because the rectal wall is relatively insensitive to the pain in the ...

  10. Prostate Ultrasound

    Medline Plus

    Full Text Available ... uses sound waves to produce pictures of a man’s prostate gland and to help diagnose symptoms such ... also called transrectal ultrasound, provides images of a man's prostate gland and surrounding tissue. The exam typically ...

  11. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... pain ambiguous genitalia and anomalies of pelvic organs early or delayed puberty in girls Pelvic ultrasound is ... sensitive to motion, and an active or crying child can prolong the examination process. To ensure a ...

  12. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... consist of a console containing a computer and electronics, a video display screen and a transducer that ... the preferred imaging modality for the diagnosis and monitoring of pregnant women and their unborn babies. Ultrasound ...

  13. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... insertion. top of page How does the procedure work? Ultrasound imaging is based on the same principles ... the transducer is pressed against the skin, it directs small pulses of inaudible, high-frequency sound waves ...

  14. Prostate Ultrasound

    Medline Plus

    Full Text Available ... gel. top of page How does the procedure work? Ultrasound imaging is based on the same principles ... the transducer is pressed against the skin, it directs small pulses of inaudible, high-frequency sound waves ...

  15. Droplets, Bubbles and Ultrasound Interactions.

    Science.gov (United States)

    Shpak, Oleksandr; Verweij, Martin; de Jong, Nico; Versluis, Michel

    2016-01-01

    The interaction of droplets and bubbles with ultrasound has been studied extensively in the last 25 years. Microbubbles are broadly used in diagnostic and therapeutic medical applications, for instance, as ultrasound contrast agents. They have a similar size as red blood cells, and thus are able to circulate within blood vessels. Perfluorocarbon liquid droplets can be a potential new generation of microbubble agents as ultrasound can trigger their conversion into gas bubbles. Prior to activation, they are at least five times smaller in diameter than the resulting bubbles. Together with the violent nature of the phase-transition, the droplets can be used for local drug delivery, embolotherapy, HIFU enhancement and tumor imaging. Here we explain the basics of bubble dynamics, described by the Rayleigh-Plesset equation, bubble resonance frequency, damping and quality factor. We show the elegant calculation of the above characteristics for the case of small amplitude oscillations by linearizing the equations. The effect and importance of a bubble coating and effective surface tension are also discussed. We give the main characteristics of the power spectrum of bubble oscillations. Preceding bubble dynamics, ultrasound propagation is introduced. We explain the speed of sound, nonlinearity and attenuation terms. We examine bubble ultrasound scattering and how it depends on the wave-shape of the incident wave. Finally, we introduce droplet interaction with ultrasound. We elucidate the ultrasound-focusing concept within a droplets sphere, droplet shaking due to media compressibility and droplet phase-conversion dynamics.

  16. Cranial Ultrasound/Head Ultrasound

    Science.gov (United States)

    ... used to screen for brain conditions associated with prematurity, such as bleeding or brain tissue damage as ... or crying child will slow the examination process. Large patients are more difficult to image by ultrasound, ...

  17. HEMISPHERIC HELICITY TREND FOR SOLAR CYCLE 24

    International Nuclear Information System (INIS)

    Hao Juan; Zhang Mei

    2011-01-01

    Using vector magnetograms obtained with the Spectro-polarimeter (SP) on board Hinode satellite, we studied two helicity parameters (local twist and current helicity) of 64 active regions that occurred in the descending phase of solar cycle 23 and the ascending phase of solar cycle 24. Our analysis gives the following results. (1) The 34 active regions of the solar cycle 24 follow the so-called hemispheric helicity rule, whereas the 30 active regions of the solar cycle 23 do not. (2) When combining all 64 active regions as one sample, they follow the hemispheric helicity sign rule as in most other observations. (3) Despite the so-far most accurate measurement of vector magnetic field given by SP/Hinode, the rule is still weak with large scatters. (4) The data show evidence of different helicity signs between strong and weak fields, confirming previous result from a large sample of ground-based observations. (5) With two example sunspots we show that the helicity parameters change sign from the inner umbra to the outer penumbra, where the sign of penumbra agrees with the sign of the active region as a whole. From these results, we speculate that both the Σ-effect (turbulent convection) and the dynamo have contributed in the generation of helicity, whereas in both cases turbulence in the convection zone has played a significant role.

  18. Evaluation of ultrasound-assisted in situ sorbent formation solid-phase extraction method for determination of arsenic in water, food and biological samples.

    Science.gov (United States)

    Ezoddin, Maryam; Majidi, Behrooz; Abdi, Khosrou

    2015-01-01

    A simple and rapid ultrasound-assisted in situ sorbent formation solid-phase extraction (UAISFSPE) coupled with electrothermal atomic absorption spectrometry detection (ET-AAS) was developed for preconcentration and determination of arsenic (As) in various samples. A small amount of cationic surfactant is dissolved in the aqueous sample containing As ions, which were complexed by ammonium pyrrolidinedithiocarbamate After shaking, a little volume of hexafluorophosphate (NaPF6) as an ion-pairing agent was added into the solution by a microsyringe. Due to the interaction between surfactant and ion-pairing agent, solid particles are formed. The alkyl groups of the surfactant in the solid particles strongly interact with the hydrophobic groups of analytes and become bound. Sonication aids the dispersion of the sorbent into the sample solution and mass transfer of the analyte into the sorbent, thus reducing the extraction time. The solid particles are centrifuged, and the sedimented particles can be dissolved in an appropriate solvent to recover the absorbed analyte. After separation, total arsenic (As(III) and As(V)) was determined by ET-AAS. Several experimental parameters were investigated and optimized. A detection limit of 7 ng L(-1) with preconcentration factor of 100 and relative standard deviation for 10 replicate determinations of 0.1 µg L(-1) As(III) were 4.5% achieved. Consequently, the method was applied to the determination of arsenic in certified reference materials, water, food and biological samples with satisfactory results.

  19. Determination of antimony and tin in beverages using inductively coupled plasma-optical emission spectrometry after ultrasound-assisted ionic liquid dispersive liquid-liquid phase microextraction.

    Science.gov (United States)

    Biata, N Raphael; Nyaba, Luthando; Ramontja, James; Mketo, Nomvano; Nomngongo, Philiswa N

    2017-12-15

    The aim of this study was to develop a simple and fast ultrasound-assisted ionic liquid dispersive liquid-liquid phase microextraction (UA-IL-DLLME) method for preconcetration of trace antimony and tin in beverage samples. The novelty of this study was based on the application of ligandless UA-IL-DLLME using low-density ionic liquid and organic solvents for preconcentration of Sb and Sn. The concentration of Sb and Sn were quantified using ICP-OES. Under the optimum conditions, the calibration graph was found to be LOQ-250µgL -1 (r 2 =0.9987) for Sb and LOQ-350µgL -1 for Sn. The LOD and LOQ of Sb and Sn ranged from 1.2to 2.5ngL -1 and 4.0 to 8.3ngL -1 , respectively, with high preconcentration factors. The precisions (%RSD) of the proposed method ranged from 2.1% to 2.5% and 3.9% to 4.7% for Sb and Sn, respectively. The proposed method was successfully applied for determination of Sb and Sn in beverages. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Ultrasound-assisted extraction and solid-phase extraction for the simultaneous determination of five amide herbicides in fish samples by gas chromatography with electron capture detection.

    Science.gov (United States)

    Qu, Zhipeng; Bai, Xiuzhi; Zhang, Ting; Yang, Zhaoguang

    2017-03-01

    An efficient sample extraction and clean-up method was developed for simultaneous determination of five amide herbicides (alachlor, acetochlor, propisochlor, metazachlor, and butachlor) in fish samples. The protocol consisted of ultrasound-assisted solvent extraction and solid-phase extraction clean-up. In detail, aliquots of homogenized fish flesh were thoroughly mixed with 20 mL of n-hexane and then extracted with ultrasonication for 40 min. Each sample was centrifuged and the supernatant was collected for the subsequent clean-up. For the sample preparation, the above supernatant was processed with a C 18 column with 3 mL of dichloromethane/n-hexane (1:1, v/v) as the eluant. Then the samples were analyzed by gas chromatography with electron capture detection. The correlation coefficients of the five calibration curves were 0.9976-0.9998 (n = 3). The limits of detection (S/N = 3, n = 11) and limits of quantification (S/N = 10, n = 11) were 0.19-0.42 and 0.63-1.39 μg/kg, respectively. The recoveries of this method were 71.2-92.6% with good precision (<4.7% relative standard deviations, n = 6). The developed method was successfully applied to monitor the five amide herbicides in fish samples collected from different cities. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Design of a phased array for the generation of adaptive radiation force along a path surrounding a breast lesion for dynamic ultrasound elastography imaging.

    Science.gov (United States)

    Ekeom, Didace; Hadj Henni, Anis; Cloutier, Guy

    2013-03-01

    This work demonstrates, with numerical simulations, the potential of an octagonal probe for the generation of radiation forces in a set of points following a path surrounding a breast lesion in the context of dynamic ultrasound elastography imaging. Because of the in-going wave adaptive focusing strategy, the proposed method is adapted to induce shear wave fronts to interact optimally with complex lesions. Transducer elements were based on 1-3 piezocomposite material. Three-dimensional simulations combining the finite element method and boundary element method with periodic boundary conditions in the elevation direction were used to predict acoustic wave radiation in a targeted region of interest. The coupling factor of the piezocomposite material and the radiated power of the transducer were optimized. The transducer's electrical impedance was targeted to 50 Ω. The probe was simulated by assembling the designed transducer elements to build an octagonal phased-array with 256 elements on each edge (for a total of 2048 elements). The central frequency is 4.54 MHz; simulated transducer elements are able to deliver enough power and can generate the radiation force with a relatively low level of voltage excitation. Using dynamic transmitter beamforming techniques, the radiation force along a path and resulting acoustic pattern in the breast were simulated assuming a linear isotropic medium. Magnitude and orientation of the acoustic intensity (radiation force) at any point of a generation path could be controlled for the case of an example representing a heterogeneous medium with an embedded soft mechanical inclusion.

  2. Ultrasound-assisted dispersive solid phase extraction of cadmium(II) and lead(II) using a hybrid nanoadsorbent composed of graphene and the zeolite clinoptilolite

    International Nuclear Information System (INIS)

    Ghazaghi, Mehri; Mousavi, Hassan Zavvar; Shirkhanloo, Hamid; Rashidi, Ali Morad

    2015-01-01

    We describe a hybrid nanoadsorbent prepared by depositing graphene on the zeolite clinoptilolite by chemical vapor deposition. The resulting sorbent is well suited for the preconcentration of lead(II) and cadmium(II) by ultrasound-assisted dispersive micro solid–phase extraction. An extraction unit has been designed and manufactured that facilitates handling of small sample volumes. The effects of sample pH, amount of sorbent, concentration and volume of elution and time of ultrasonic bath were investigated. The nanoadsorbent was characterized by scanning electron microscopy, X-ray diffraction and energy dispersive X-ray microanalysis, all of which revealed the high surface area of the graphene sheets on the clinoptilolite. The extraction recoveries when using the new nanoadsorbent are 97 % (as opposed to a mere 10 % in case of clinoptilolite only). It is assumed that the graphene sheets located around the porous structure of clinoptilolite are acting as a barrier against macromolecules potentially existing in the sample matrices. The method was applied to the determination of lead and cadmium in water and human serum samples by electrothermal atomic absorption spectrometry. The detection limits were as low as 70 and 4 ng L −1 for Pb(II) and Cd(II), respectively. The accuracy of the method was underpinned by correct analysis of a standard reference material (SRM: 203105 Seronorm Trace Elements Serum L-2). (author)

  3. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... guide biopsy of breast cancer ( see the Ultrasound-Guided Breast Biopsy page . diagnose a variety of heart ... Articles and Media Angioplasty and Vascular Stenting Ultrasound-Guided Breast Biopsy Obstetric Ultrasound Ultrasound - Prostate Biopsies - Overview ...

  4. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... of an ultrasound examination. Doppler ultrasound , also called color Doppler ultrasonography, is a special ultrasound technique that ... kidneys. There are three types of Doppler ultrasound: Color Doppler uses a computer to convert Doppler measurements ...

  5. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... Index A-Z General Ultrasound Ultrasound imaging uses sound waves to produce pictures of the inside of ... pictures of the inside of the body using sound waves. Ultrasound imaging, also called ultrasound scanning or ...

  6. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... those sound waves to create an image. Ultrasound examinations do not use ionizing radiation (as used in ... ultrasound study may be part of an ultrasound examination. Doppler ultrasound , also called color Doppler ultrasonography, is ...

  7. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... What are the limitations of General Ultrasound Imaging? What is General Ultrasound Imaging? Ultrasound is safe and ... be heard with every heartbeat. top of page What are some common uses of the procedure? Ultrasound ...

  8. The role of acoustic nonlinearity in tissue heating behind a rib cage using a high-intensity focused ultrasound phased array

    Science.gov (United States)

    Yuldashev, Petr V.; Shmeleva, Svetlana M.; Ilyin, Sergey A.; Sapozhnikov, Oleg A.; Gavrilov, Leonid R.; Khokhlova, Vera A.

    2013-04-01

    The goal of this study was to investigate theoretically the effects of nonlinear propagation in a high-intensity focused ultrasound (HIFU) field produced by a therapeutic phased array and the resultant heating of tissue behind a rib cage. Three configurations of focusing were simulated: in water, in water with ribs in the beam path and in water with ribs backed by a layer of soft tissue. The Westervelt equation was used to model the nonlinear HIFU field, and a 1 MHz phased array consisting of 254 circular elements was used as a boundary condition to the model. The temperature rise in tissue was modelled using the bioheat equation, and thermally necrosed volumes were calculated using the thermal dose formulation. The shapes of lesions predicted by the modelling were compared with those previously obtained in in vitro experiments at low-power sonications. Intensity levels at the face of the array elements that corresponded to the formation of high-amplitude shock fronts in the focal region were determined as 10 W cm-2 in the free field in water and 40 W cm-2 in the presence of ribs. It was shown that exposures with shocks provided a substantial increase in tissue heating, and its better spatial localization in the main focal region only. The relative effects of overheating ribs and splitting of the focus due to the periodic structure of the ribs were therefore reduced. These results suggest that utilizing nonlinear propagation and shock formation effects can be beneficial for inducing confined HIFU lesions when irradiating through obstructions such as ribs. Design of compact therapeutic arrays to provide maximum power outputs with lower intensity levels at the elements is necessary to achieve shock wave regimes for clinically relevant sonication depths in tissue.

  9. A new method for ultrasound detection of interfacial position in gas-liquid two-phase flow.

    Science.gov (United States)

    Coutinho, Fábio Rizental; Ofuchi, César Yutaka; de Arruda, Lúcia Valéria Ramos; Neves, Flávio; Morales, Rigoberto E M

    2014-05-22

    Ultrasonic measurement techniques for velocity estimation are currently widely used in fluid flow studies and applications. An accurate determination of interfacial position in gas-liquid two-phase flows is still an open problem. The quality of this information directly reflects on the accuracy of void fraction measurement, and it provides a means of discriminating velocity information of both phases. The algorithm known as Velocity Matched Spectrum (VM Spectrum) is a velocity estimator that stands out from other methods by returning a spectrum of velocities for each interrogated volume sample. Interface detection of free-rising bubbles in quiescent liquid presents some difficulties for interface detection due to abrupt changes in interface inclination. In this work a method based on velocity spectrum curve shape is used to generate a spatial-temporal mapping, which, after spatial filtering, yields an accurate contour of the air-water interface. It is shown that the proposed technique yields a RMS error between 1.71 and 3.39 and a probability of detection failure and false detection between 0.89% and 11.9% in determining the spatial-temporal gas-liquid interface position in the flow of free rising bubbles in stagnant liquid. This result is valid for both free path and with transducer emitting through a metallic plate or a Plexiglas pipe.

  10. Therapeutic ultrasound

    International Nuclear Information System (INIS)

    Crum, Lawrence A

    2004-01-01

    The use of ultrasound in medicine is now quite commonplace, especially with the recent introduction of small, portable and relatively inexpensive, hand-held diagnostic imaging devices. Moreover, ultrasound has expanded beyond the imaging realm, with methods and applications extending to novel therapeutic and surgical uses. These applications broadly include: tissue ablation, acoustocautery, lipoplasty, site-specific and ultrasound mediated drug activity, extracorporeal lithotripsy, and the enhancement of natural physiological functions such as wound healing and tissue regeneration. A particularly attractive aspect of this technology is that diagnostic and therapeutic systems can be combined to produce totally non-invasive, imageguided therapy. This general lecture will review a number of these exciting new applications of ultrasound and address some of the basic scientific questions and future challenges in developing these methods and technologies for general use in our society. We shall particularly emphasize the use of High Intensity Focused Ultrasound (HIFU) in the treatment of benign and malignant tumors as well as the introduction of acoustic hemostasis, especially in organs which are difficult to treat using conventional medical and surgical techniques. (amum lecture)

  11. Hemisphere partition function and monodromy

    Energy Technology Data Exchange (ETDEWEB)

    Erkinger, David; Knapp, Johanna [Institute for Theoretical Physics, TU Wien,Wiedner Hauptstrasse 8-10, 1040 Vienna (Austria)

    2017-05-29

    We discuss D-brane monodromies from the point of view of the gauged linear sigma model. We give a prescription on how to extract monodromy matrices directly from the hemisphere partition function. We illustrate this procedure by recomputing the monodromy matrices associated to one-parameter Calabi-Yau hypersurfaces in weighted projected space.

  12. Task Specific Inter-Hemispheric Coupling in Human Subthalamic Nuclei

    Directory of Open Access Journals (Sweden)

    Felix eDarvas

    2014-09-01

    Full Text Available Cortical networks and quantitative measures of connectivity are integral to the study of brain function. Despite lack of direct connections between left and right subthalamic nuclei (STN, there are apparent physiological connections. During clinical examination of patients with Parkinson’s Disease (PD, this connectivity is exploited to enhance signs of PD, yet our understanding of this connectivity is limited. We hypothesized that movement leads to synchronization of neural oscillations in bilateral STN, and we implemented phase coherence, a measure of phase-locking between cortical sites in a narrow frequency band, to demonstrate this synchronization. We analyzed task specific phase synchronization and causality between left and right STN local field potentials (LFP recorded from both hemispheres simultaneously during a cued movement task in four subjects with PD who underwent Deep Brain Stimulation (DBS surgery. We used a data driven approach to determine inter-hemispheric channel pairs and frequencies with a task specific increase in phase locking.We found significant phase locking between hemispheres in alpha frequency (8-12 Hz in all subjects concurrent with movement of either hand. In all subjects, phase synchronization increased over baseline upon or prior to hand movement onset and lasted until the motion ceased. Left and right hand movement showed similar patterns. Granger causality at the phase-locking frequencies between synchronized electrodes revealed a unidirectional causality from right to left STN regardless of which side was moved.Phase synchronization across hemispheres between basal ganglia supports existence of a bilateral network having lateralized regions of specialization for motor processing. Our results suggest this bilateral network is activated by a unilateral motor program. Understanding phase synchronization in natural brain functions is critical to development of future DBS systems that augment goal directed

  13. Determination of size distribution of bubbles in a bubbly column two phase flows by ultrasound and neural networks

    International Nuclear Information System (INIS)

    Baroni, Douglas B.; Lamy, Carlos A.; Bittencourt, Marcelo S.Q.; Pereira, Claudio M.N.A.; Cunha Filho, Jurandyr S.; Motta, Mauricio S.

    2011-01-01

    The development of advanced nuclear reactor conceptions depends largely on the amount of available data to the designer. Non invasive ultrasonic techniques can contribute to the evaluation of gas-liquid two-phase regimes in the nuclear thermo-hydraulic circuits. A key-point for success of those techniques is the interpretation of the ultrasonic signal. In this work, a methodology based in artificial neural networks (ANN) is proposed to predict size distribution of bubbles in a bubbly flow. To accomplish that, an air feed system control was used to obtain specific bubbly flows in an experimental system utilizing a Plexiglas vertical bubbly column. Four different size distribution of bubbles were generated. The bubbles were photographed and measured. To evaluate the different size distribution of bubbles it was used the ultrasonic reflected echo on the opposite wall of the column. Then, an ANN has been developed for predicting size distribution of bubbles by using the frequency spectra of the ultrasonic signal as input. A trained artificial neural network using ultrasonic signal in the frequency domain can evaluate with a good precision the size distribution of bubbles generated in this system. (author)

  14. Graphene nanosheets preparation using magnetic nanoparticle assisted liquid phase exfoliation of graphite: The coupled effect of ultrasound and wedging nanoparticles.

    Science.gov (United States)

    Hadi, Alireza; Zahirifar, Jafar; Karimi-Sabet, Javad; Dastbaz, Abolfazl

    2018-06-01

    This study aims to investigate a novel technique to improve the yield of liquid phase exfoliation of graphite to graphene sheets. The method is based on the utilization of magnetic Fe 3 O 4 nanoparticles as "particle wedge" to facilitate delamination of graphitic layers. Strong shear forces resulted from the collision of Fe 3 O 4 particles with graphite particles, and intense ultrasonic waves lead to enhanced exfoliation of graphite. High quality of graphene sheets along with the ease of Fe 3 O 4 particle separation from graphene solution which arises from the magnetic nature of Fe 3 O 4 nanoparticles are the unique features of this approach. Initial graphite flakes and produced graphene sheets were characterized by various methods including field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Raman spectroscopy, atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and Zeta potential analysis. Moreover, the effect of process factors comprising initial graphite concentration, Fe 3 O 4 nanoparticles concentration, sonication time, and sonication power were investigated. Results revealed that graphene preparation yield and the number of layers could be manipulated by the presence of magnetic nanoparticles. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. Determination of size distribution of bubbles in a bubbly column two phase flows by ultrasound and neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Baroni, Douglas B.; Lamy, Carlos A.; Bittencourt, Marcelo S.Q.; Pereira, Claudio M.N.A., E-mail: douglasbaroni@ien.gov.b, E-mail: lamy@ien.gov.b, E-mail: bittenc@ien.gov.b, E-mail: cmnap@ien.gov.b [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Cunha Filho, Jurandyr S. [Escola Tecnica Estadual Visconde de Maua (ETEVM/RJ), Rio de Janeiro, RJ (Brazil); Motta, Mauricio S., E-mail: mmotta@cefet-rj.b [Centro Federal de Educacao Tecnologica Celso Suckow da Fonseca (CEFET/RJ), Rio de Janeiro, RJ (Brazil)

    2011-07-01

    The development of advanced nuclear reactor conceptions depends largely on the amount of available data to the designer. Non invasive ultrasonic techniques can contribute to the evaluation of gas-liquid two-phase regimes in the nuclear thermo-hydraulic circuits. A key-point for success of those techniques is the interpretation of the ultrasonic signal. In this work, a methodology based in artificial neural networks (ANN) is proposed to predict size distribution of bubbles in a bubbly flow. To accomplish that, an air feed system control was used to obtain specific bubbly flows in an experimental system utilizing a Plexiglas vertical bubbly column. Four different size distribution of bubbles were generated. The bubbles were photographed and measured. To evaluate the different size distribution of bubbles it was used the ultrasonic reflected echo on the opposite wall of the column. Then, an ANN has been developed for predicting size distribution of bubbles by using the frequency spectra of the ultrasonic signal as input. A trained artificial neural network using ultrasonic signal in the frequency domain can evaluate with a good precision the size distribution of bubbles generated in this system. (author)

  16. Effects of memory load on hemispheric asymmetries of colour memory.

    Science.gov (United States)

    Clapp, Wes; Kirk, Ian J; Hausmann, Markus

    2007-03-01

    Hemispheric asymmetries in colour perception have been a matter of debate for some time. Recent evidence suggests that lateralisation of colour processing may be largely task specific. Here we investigated hemispheric asymmetries during different types and phases of a delayed colour-matching (recognition) memory task. A total of 11 male and 12 female right-handed participants performed colour-memory tasks. The task involved presentation of a set of colour stimuli (encoding), and subsequent indication (forced choice) of which colours in a larger set had previously appeared at the retrieval or recognition phase. The effect of memory load (set size), and the effect of lateralisation at the encoding or retrieval phases were investigated. Overall, the results indicate a right hemisphere advantage in colour processing, which was particularly pronounced in high memory load conditions, and was seen in males rather than female participants. The results suggest that verbal (mnemonic) strategies can significantly affect the magnitude of hemispheric asymmetries in a non-verbal task.

  17. Response of the meridional overturning circulation to variable buoyancy forcing in a double hemisphere basin

    Energy Technology Data Exchange (ETDEWEB)

    Lucas, Marc A. [National Oceanography Centre, University of Southampton, School of Ocean and Earth Science, Southampton (United Kingdom); Collecte Localisation Satellite, Ramonville Saint Agne (France); Hirschi, J.J.M. [National Oceanography Centre, University of Southampton, School of Ocean and Earth Science, Southampton (United Kingdom); Marotzke, J. [Max-Planck-Institut fuer Meteorologie, Hamburg (Germany)

    2010-04-15

    We consider how a highly idealized double-hemisphere basin responds to a zonally constant restoring surface temperature profile that oscillates in time, with periods ranging from 0.5 to 32,000 years. In both hemispheres, the forcing is similar but can be either in phase or out of phase. The set-up is such that the Northern Hemisphere always produces the densest waters. The model's meridional overturning circulation (MOC) exhibits a strong response in both hemispheres on decadal to multi-millennial timescales. The amplitude of the oscillations reaches up to 140% of the steady-state maximum MOC and exhibits resonance-like behaviour, with a maximum at centennial to millennial forcing periods. When the forcing is in phase between the Northern and Southern Hemispheres, there is a marked decrease in the amplitude of the MOC response as the forcing period is increased beyond the resonance period. In this case the resonance-like behaviour is identical to the one we found earlier in a single-hemisphere model and occurs for the same reasons. When the forcing is out of phase between the Northern and Southern Hemispheres, the amplitude of the MOC response is substantially greater for long forcing periods (millennial and longer), particularly in the Southern Hemisphere. This increased MOC amplitude occurs because for an out of phase forcing, either the northern or the southern deep water source is always active, leading to generally colder bottom waters and thus greater stratification in the opposite hemisphere. This increased stratification in turn stabilises the water column and thus reduces the strength of the weaker overturning cell. The interaction of the two hemispheres leads to response timescales of the deep ocean at half the forcing period. Our results suggest a possible explanation for the half-precessional time scale observed in the deep Atlantic Ocean palaeo-temperature record. (orig.)

  18. Modeling and verification of hemispherical solar still using ANSYS CFD

    Energy Technology Data Exchange (ETDEWEB)

    Panchal, Hitesh N. [KSV University, Gujarat Power Engineering and Research Institute, Mehsana (India); Shah, P.K. [Silver Oak College of Engineering and Technology, Ahmedabad, Gujarat (India)

    2013-07-01

    In every efficient solar still design, water temperature, vapor temperature and distillate output, and difference between water temperature and inner glass cover temperatures are very important. Here, two dimensional three phase model of hemispherical solar still is made for evaporation as well as condensation process in ANSYS CFD. Simulation results like water temperature, vapor temperature, distillate output compared with actual experimental results of climate conditions of Mehsana (latitude of 23° 59’ and longitude of 72° 38) of hemispherical solar still. Water temperature and distillate output were good agreement with actual experimental results. Study shows that ANSYS-CFD is very powerful as well as efficient tool for design, comparison purpose of hemispherical solar still.

  19. Experimental Study on CHF in a Hemispherical Narrow Gap

    International Nuclear Information System (INIS)

    Jeong, J.H.; Park, R.J.; Kang, K.H.; Kim, S.B.; Kim, H.D.

    1999-01-01

    As a part of the SONATA-IV program, KAERI is conducting an experimental investigation of critical heat flux(CHF) in hemispherical narrow gaps. A visualization experiment, VISU-II, was done as the first step to get a visual observation of the flow behaviour inside a hemispherical gap and to understand the CHF-triggering mechanism. It was observed that the counter-current flow limitation (CCFL) phenomenon prevented water from wetting the heater surface and induced CHF. The CHFG (Critical Heat Flux in Gap) test is now being performed to measure the CHF and to investigate the inherent cooling mechanism in hemispherical narrow gaps. Temperature measurements over the heater surface show that the two-phase flow behaviour inside the gaps could be quite different from the other usual CHF experiments. The measured CHF points are lower than the predictions by existing empirical correlations based on the data measured with small-scale horizontal plates and vertical annulus. (authors)

  20. Acoustic Cavitation Enhances Focused Ultrasound Ablation with Phase-Shift Inorganic Perfluorohexane Nanoemulsions: An In Vitro Study Using a Clinical Device

    Directory of Open Access Journals (Sweden)

    Lu-Yan Zhao

    2016-01-01

    Full Text Available Purpose. To investigate whether acoustic cavitation could increase the evaporation of a phase-shift inorganic perfluorohexane (PFH nanoemulsion and enhance high intensity focused ultrasound (HIFU ablation. Materials and Methods. PFH was encapsulated by mesoporous silica nanocapsule (MSNC to form a nanometer-sized droplet (MSNC-PFH. It was added to a tissue-mimicking phantom, whereas phosphate buffered saline (PBS was added as a control (PBS-control. HIFU (Pac=150 W, t=5/10 s exposures were performed in both phantoms with various duty cycles (DC. US images, temperature, and cavitation emissions were recorded during HIFU exposure. HIFU-induced lesions were measured and calculated. Results. Compared to PBS-control, MSNC-PFH nanoemulsion could significantly increase the volume of HIFU-induced lesion (P<0.01. Peak temperatures were 78.16 ± 5.64°C at a DC of 100%, 70.17 ± 6.43°C at 10%, 53.17 ± 4.54°C at 5%, and 42.00 ± 5.55°C at 2%, respectively. Inertial cavitation was much stronger in the pulsed-HIFU than that in the continuous-wave HIFU exposure. Compared to 100%-DC exposure, the mean volume of lesion induced by 5 s exposure at 10%-DC was significantly larger, but smaller at 2%-DC. Conclusions. MSNC-PFH nanoemulsion can significantly enhance HIFU ablation. Appropriate pulsed-HIFU exposure could significantly increase the volume of lesion and reduce total US energy required for HIFU ablation.

  1. Prostate Ultrasound

    Medline Plus

    Full Text Available ... the prostate. help diagnose the cause of a man's infertility. A transrectal ultrasound of the prostate gland is typically used to help diagnose symptoms such as: a nodule felt by a physician during a routine physical exam or prostate cancer screening exam. an elevated ...

  2. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... and Resources RTAnswers.org Radiation Therapy for Gynecologic Cancers Radiation Therapy for Prostate Cancer top of page This page was reviewed on ... with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. ... Images related to Ultrasound - Pelvis Sponsored by Please ...

  3. Prostate Ultrasound

    Medline Plus

    Full Text Available ... body tissue through which the sound travels. A small amount of gel is put on the skin to allow the sound waves to travel from the transducer to the examined area within the body and then back again. Ultrasound ...

  4. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... body tissue through which the sound travels. A small amount of gel is put on the skin to allow the sound waves to travel from the transducer to the examined area within the body and then back again. Ultrasound ...

  5. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... ultrasound exams are also used to monitor the health and development of an embryo or fetus during pregnancy. See the ... can help to identify and evaluate a variety of urinary and reproductive system disorders in both sexes without x-ray exposure. ...

  6. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... of the reflected sound waves (called the Doppler effect). A computer collects and processes the sounds and creates graphs ... Ultrasound provides real-time imaging, making it a good tool for guiding minimally ... known harmful effects on humans. top of page What are the ...

  7. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... blood vessels. Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions. ...

  8. Prostate Ultrasound

    Medline Plus

    Full Text Available ... symptoms such as difficulty urinating or an elevated blood test result. It’s also used to investigate a nodule ... exam or prostate cancer screening exam. an elevated blood test result. difficulty urinating. Because ultrasound provides real-time ...

  9. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... in which needles are used to extract a sample of cells from organs for laboratory testing. Doppler ultrasound images can help the physician to see and evaluate: blockages to blood flow (such as clots) narrowing of vessels tumors ...

  10. Prostate Ultrasound

    Medline Plus

    Full Text Available ... exam or prostate cancer screening exam. an elevated blood test result. difficulty urinating. Because ultrasound provides real-time images, it also can be used to guide procedures such as needle biopsies , in which a needle is used to sample cells (tissue) from an abnormal area in the ...

  11. Prostate Ultrasound

    Medline Plus

    Full Text Available ... do not use ionizing radiation (as used in x-rays ), thus there is no radiation exposure to the ... tissues that do not show up well on x-ray images. Ultrasound causes no health problems and may ...

  12. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... do not use ionizing radiation (as used in x-rays ), thus there is no radiation exposure to the ... tissues that do not show up well on x-ray images. Ultrasound is the preferred imaging modality for ...

  13. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... the amplitude (loudness), frequency (pitch) and time it takes for the ultrasound signal to return from the area within the patient that is being examined to the transducer (the device placed on the patient's skin to send and ...

  14. Prostate Ultrasound

    Medline Plus

    Full Text Available ... the amplitude (loudness), frequency (pitch) and time it takes for the ultrasound signal to return from the area within the patient that is being examined to the transducer (the device placed on the patient's skin to send and ...

  15. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... the patient. Because ultrasound images are captured in real-time, they can show the structure and movement of ... by a computer, which in turn creates a real-time picture on the monitor. One or more frames ...

  16. Obstetrical ultrasound

    International Nuclear Information System (INIS)

    Bundy, A.L.

    1988-01-01

    The use of diagnostic ultrasound in obstetrics may provide fuel for legal action. While most legal implications of this relatively new imaging modality are purely speculative, some have already given rise to legal action. Several situations will likely provide a basis for the courts to find against the physician. The failure to perform a sonogram when clinically indicated will most likely be the strongest plaintiff argument. Other major concerns include the use and availability of state-of-the-art equipment, as well as interpretation of the scans by a trained physician. Obstetrical ultrasound is usually performed by a radiologist or obstetrician. However, many physicians performing these examinations have had little or no formal training in the field. While this is now being remedied by the respective board examines who require a certain amount of training, it may not be enough. When ultrasound-related cases reach the courts, the involved physicians will most likely be regarded as experts in the field and, therefore, will be held to a very high standard of care. This would be difficult to achieve without formal training. At the present time, the American Board of Radiology requires more training time in ultrasound than the American Board of Obstetrics and Gynecology

  17. Hemispheric Laterality in Music and Math

    Science.gov (United States)

    Szirony, Gary Michael; Burgin, John S.; Pearson, L. Carolyn

    2008-01-01

    Hemispheric laterality may be a useful concept in teaching, learning, training, and in understanding more about human development. To address this issue, a measure of hemispheric laterality was compared to musical and mathematical ability. The Human Information Processing Survey (HIPS) instrument, designed to measure hemispheric laterality, was…

  18. Right Hemisphere Dominance in Visual Statistical Learning

    Science.gov (United States)

    Roser, Matthew E.; Fiser, Jozsef; Aslin, Richard N.; Gazzaniga, Michael S.

    2011-01-01

    Several studies report a right hemisphere advantage for visuospatial integration and a left hemisphere advantage for inferring conceptual knowledge from patterns of covariation. The present study examined hemispheric asymmetry in the implicit learning of new visual feature combinations. A split-brain patient and normal control participants viewed…

  19. Hemispheric processing asymmetries: implications for memory.

    Science.gov (United States)

    Funnell, M G; Corballis, P M; Gazzaniga, M S

    2001-01-01

    Recent research has demonstrated that memory for words elicits left hemisphere activation, faces right hemisphere activation, and nameable objects bilateral activation. This pattern of results was attributed to dual coding of information, with the left hemisphere employing a verbal code and the right a nonverbal code. Nameable objects can be encoded either verbally or nonverbally and this accounts for their bilateral activation. We investigated this hypothesis in a callosotomy patient. Consistent with dual coding, the left hemisphere was superior to the right in memory for words, whereas the right was superior for faces. Contrary to prediction, performance on nameable pictures was not equivalent in the two hemispheres, but rather resulted in a right hemisphere superiority. In addition, memory for pictures was significantly better than for either words or faces. These findings suggest that the dual code hypothesis is an oversimplification of the processing capabilities of the two hemispheres.

  20. Ionic liquid ultrasound-assisted dispersive liquid-liquid microextraction based on solidification of the aqueous phase for preconcentration of heavy metals ions prior to determination by LC-UV.

    Science.gov (United States)

    Werner, Justyna

    2018-05-15

    Ionic liquid ultrasound-assisted dispersive liquid-liquid microextraction based on solidification of the aqueous phase was used for preconcentration of Ni 2+ , Co 2+ , Cd 2+ , Cu 2+ , Pb 2+ in natural water samples prior to liquid chromatography with UV detection. In the proposed method, the ammonium pyrrolidinedithiocarbamate was used as a complexing agent and the phosphonium ionic liquid trihexyl(tetradecyl)phosphonium bis[(2,4,4-trimethyl)pentyl]phosphinate (Cyphos IL 104) was used as an extractant. Ultrasound energy was used to disperse the extractant in the aqueous phase. After microextraction, the ionic liquid and aqueous phases were separated by centrifugation. Then the aqueous phase was frozen and the lighter than water ionic liquid phase containing metal ions complexes with pyrrolidinedithiocarbamate was separated and dissolved in a small volume of methanol prior to injection into the liquid chromatograph. Several parameters including the volume of extractant, the pH of the sample, the concentration of complexing agent, the time of ultrasound energy treatment, the time and speed of centrifugation and the effect of ionic strength were optimized. Under the optimized conditions (10 µL of Cyphos IL 104, pH = 5, 0.3% w/v ammonium pyrrolidinedithiocarbamate, 60 s of ultrasound use, 5 min/5000 rpm (2516×g) of centrifugation, 2.0 mg of NaCl), preconcentration factors were 211, 210, 209, 207 and 211 for Ni 2+ , Co 2+ , Cd 2+ , Cu 2+ and Pb 2+ respectively. Linearity was observed in the ranges 0.2-75.0 µg L -1 for Pb 2+ , Cd 2+ , Co 2+ and 0.5-100.0 µg L -1 for Cu 2+ , Ni 2+ . The limits of detection were 0.03 µg L -1 for Ni 2+ , 0.03 µg L -1 for Co 2+ , 0.03 µg L -1 for Cd 2+ , 0.02 µg L -1 for Cu 2+ , 0.02 µg L -1 for Pb 2+ , respectively. The accuracy of this method was evaluated by preconcentration and determination of Ni 2+ , Co 2+ , Cd 2+ , Cu 2+ , Pb 2+ in certified reference materials (TMRAIN-04 and NIST 1643e

  1. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... of page How is the procedure performed? For most ultrasound exams, you will be positioned lying face- ... Ultrasound examinations are painless and easily tolerated by most patients. Ultrasound exams in which the transducer is ...

  2. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... ultrasound. top of page How does the procedure work? Ultrasound imaging is based on the same principles ... modality for the diagnosis and monitoring of pregnant women and their unborn babies. Ultrasound provides real-time ...

  3. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... medical test that helps physicians diagnose and treat medical conditions. Conventional ultrasound displays the images in thin, flat sections of the body. Advancements in ultrasound technology include three-dimensional (3-D) ultrasound that formats ...

  4. Ultrasound guided supraclavicular block.

    LENUS (Irish Health Repository)

    Hanumanthaiah, Deepak

    2013-09-01

    Ultrasound guided regional anaesthesia is becoming increasingly popular. The supraclavicular block has been transformed by ultrasound guidance into a potentially safe superficial block. We reviewed the techniques of performing supraclavicular block with special focus on ultrasound guidance.

  5. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... D images. A Doppler ultrasound study may be part of an ultrasound examination. Doppler ultrasound , also called ... terms of the distance traveled per unit of time, rather than as a color picture. It can ...

  6. Awake right hemisphere brain surgery.

    Science.gov (United States)

    Hulou, M Maher; Cote, David J; Olubiyi, Olutayo I; Smith, Timothy R; Chiocca, E Antonio; Johnson, Mark D

    2015-12-01

    We report the indications and outcomes of awake right hemispheric brain surgery, as well as a rare patient with crossed aphasia. Awake craniotomies are often performed to protect eloquent cortex. We reviewed the medical records for 35 of 96 patients, in detail, who had awake right hemisphere brain operations. Intraoperative cortical mapping of motor and/or language function was performed in 29 of the 35 patients. A preoperative speech impairment and left hand dominance were the main indicators for awake right-sided craniotomies in patients with right hemisphere lesions. Four patients with lesion proximity to eloquent areas underwent awake craniotomies without cortical mapping. In addition, one patient had a broncho-pulmonary fistula, and another had a recent major cardiac procedure that precluded awake surgery. An eloquent cortex representation was identified in 14 patients (48.3%). Postoperatively, seven of 17 patients (41.1%) who presented with weakness, experienced improvements in their motor functions, 11 of 16 (68.7%) with seizures became seizure-free, and seven of nine (77.7%) with moderate to severe headaches and one of two with a visual field deficit improved significantly. There were also improvements in speech and language functions in all patients who presented with speech difficulties. A right sided awake craniotomy is an excellent option for left handed patients, or those with right sided cortical lesions that result in preoperative speech impairments. When combined with intraoperative cortical mapping, both speech and motor function can be well preserved. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Optimization of ultrasound-assisted dispersive solid-phase microextraction based on nanoparticles followed by spectrophotometry for the simultaneous determination of dyes using experimental design.

    Science.gov (United States)

    Asfaram, Arash; Ghaedi, Mehrorang; Goudarzi, Alireza

    2016-09-01

    A simple, low cost and ultrasensitive method for the simultaneous preconcentration and determination of trace amount of auramine-O and malachite green in aqueous media following accumulation on novel and lower toxicity nanomaterials by ultrasound-assisted dispersive solid phase micro-extraction (UA-DSPME) procedure combined with spectrophotometric has been described. The Mn doped ZnS nanoparticles loaded on activated carbon were characterized by Field emission scanning electron microscopy (FE-SEM), particle size distribution, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) analyses and subsequently were used as green and efficient material for dyes accumulation. Contribution of experimental variables such as ultrasonic time, ultrasonic temperature, adsorbent mass, vortex time, ionic strength, pH and elution volume were optimized through experimental design, and while the preconcentrated analytes were efficiently eluted by acetone. Preliminary Plackett-Burman design was applied for selection of most significant factors and giving useful information about their main and interaction part of significant variables like ultrasonic time, adsorbent mass, elution volume and pH were obtained by central composite design combined with response surface analysis and optimum experimental conditions was set at pH of 8.0, 1.2mg of adsorbent, 150μL eluent and 3.7min sonication. Under optimized conditions, the average recoveries (five replicates) for two dyes (spiked at 500.0ngmL(-1)) changes in the range of 92.80-97.70% with acceptable RSD% less than 4.0% over a linear range of 3.0-5000.0ngmL(-1) for the AO and MG in water samples with regression coefficients (R(2)) of 0.9975 and 0.9977, respectively. Acceptable limits of detection of 0.91 and 0.61ngmL(-1) for AO and MG, respectively and high accuracy and repeatability are unique advantages of present method to improve the figures of merit for their accurate determination at trace level in complicated

  8. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... through blood vessels. Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions. Conventional ultrasound displays the images in thin, ...

  9. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... and treat medical conditions. Conventional ultrasound displays the images in thin, flat sections of the body. Advancements in ultrasound technology include three-dimensional (3- ...

  10. On the evaluation of temperature dependence of elastic constants of martensitic phases in shape memory alloys from resonant ultrasound spectroscopy studies

    Czech Academy of Sciences Publication Activity Database

    Landa, Michal; Sedlák, Petr; Šittner, Petr; Seiner, Hanuš; Heller, Luděk

    481-482, - (2008), s. 567-573 ISSN 0921-5093 R&D Projects: GA ČR GA101/06/0768 Institutional research plan: CEZ:AV0Z20760514; CEZ:AV0Z10100520 Keywords : modal resonant ultrasound spectroscopy * elastic properties * shape memory alloy s Subject RIV: BI - Acoustics Impact factor: 1.806, year: 2008

  11. An overview of Fukushima radionuclides measured in the northern hemisphere

    International Nuclear Information System (INIS)

    Thakur, P.; Ballard, S.; Nelson, R.

    2013-01-01

    The Great East Japan Earthquake and tsunami on March 11, 2011 resulted in the tragic accident at the Fukushima Nuclear Power Plant (NPP) and subsequently uncontrolled release of radioactive contaminants into the atmosphere. This review article attempts to compile and interpret data collected by various national and international monitoring networks in response to the Fukushima releases across the northern hemisphere. The majority of the releases occurred during the period March 12–22 with a maximum release phase from March 14–17, 2011. The radioactivity released was dominated by volatile fission products including isotopes of the noble gases (xenon and krypton), iodine, cesium, and tellurium. The radioactive gases and particles released in the accident were dispersed over the middle latitudes of the entire northern hemisphere and for the first time also measured in the southern Hemisphere. Isotopes of iodine and cesium were detected in air, water, milk and food samples collected across the entire northern hemisphere. Elevated levels of fission products were detected from March to May 2011 at many locations over the northern hemisphere. This article focuses on the most prevalent cesium and iodine isotopes, but other secondary isotopes are also discussed. Spatial and temporal patterns and differences are contrasted. The activity ratios of 131 I/ 137 Cs and 134 Cs/ 137 Cs measured at several locations are evaluated to gain an insight into the fuel burn-up, the inventory of radionuclides in the reactor and the isotopic signature of the accident. It is important to note that all of the radiation levels detected outside of Japan have been very low and are well below any level of public and environmental hazard. - Graphical abstract: The trace levels of radioactivity in air, water, and milk samples collected across the northern hemisphere between March–May, 2011 from the damaged Fukushima Daiichi nuclear power plant, Japan are discussed. Highlights: • We report

  12. An overview of Fukushima radionuclides measured in the northern hemisphere

    Energy Technology Data Exchange (ETDEWEB)

    Thakur, P., E-mail: pthakur@cemrc.org [Carlsbad Environmental Monitoring and Research Center, 1400 University Drive, Carlsbad, NM 88220 (United States); Ballard, S. [Carlsbad Environmental Monitoring and Research Center, 1400 University Drive, Carlsbad, NM 88220 (United States); Nelson, R. [Department of Energy, Carlsbad Field Office, 4021, National Parks Hwy, Carlsbad, NM 88220 (United States)

    2013-08-01

    The Great East Japan Earthquake and tsunami on March 11, 2011 resulted in the tragic accident at the Fukushima Nuclear Power Plant (NPP) and subsequently uncontrolled release of radioactive contaminants into the atmosphere. This review article attempts to compile and interpret data collected by various national and international monitoring networks in response to the Fukushima releases across the northern hemisphere. The majority of the releases occurred during the period March 12–22 with a maximum release phase from March 14–17, 2011. The radioactivity released was dominated by volatile fission products including isotopes of the noble gases (xenon and krypton), iodine, cesium, and tellurium. The radioactive gases and particles released in the accident were dispersed over the middle latitudes of the entire northern hemisphere and for the first time also measured in the southern Hemisphere. Isotopes of iodine and cesium were detected in air, water, milk and food samples collected across the entire northern hemisphere. Elevated levels of fission products were detected from March to May 2011 at many locations over the northern hemisphere. This article focuses on the most prevalent cesium and iodine isotopes, but other secondary isotopes are also discussed. Spatial and temporal patterns and differences are contrasted. The activity ratios of {sup 131}I/{sup 137}Cs and {sup 134}Cs/{sup 137}Cs measured at several locations are evaluated to gain an insight into the fuel burn-up, the inventory of radionuclides in the reactor and the isotopic signature of the accident. It is important to note that all of the radiation levels detected outside of Japan have been very low and are well below any level of public and environmental hazard. - Graphical abstract: The trace levels of radioactivity in air, water, and milk samples collected across the northern hemisphere between March–May, 2011 from the damaged Fukushima Daiichi nuclear power plant, Japan are discussed. Highlights

  13. Vascular ultrasound.

    Science.gov (United States)

    Pilcher, D B; Ricci, M A

    1998-04-01

    Surgeon-interpreted diagnostic ultrasound has become the preferred screening test and often the definitive test for the diagnosis of arterial stenosis, aneurysm, and venous thrombosis. As a modality for surveillance, its noninvasive quality makes it particularly appealing as the test of choice to screen patients for abdominal aortic aneurysms or to perform follow-up examinations on those patients with a carotid endartectomy or in situ bypass grafts. The increasing reliance on intraoperative duplex imaging of vascular procedures demands that the surgeon learn the skills to perform the studies without a technologist or radiologist to interpret the examination.

  14. Bilateral versus ipsilesional cortico-subcortical activity patterns in stroke show hemispheric dependence.

    Science.gov (United States)

    Vidal, Ana C; Banca, Paula; Pascoal, Augusto G; Cordeiro, Gustavo; Sargento-Freitas, João; Gouveia, Ana; Castelo-Branco, Miguel

    2018-01-01

    Background Understanding of interhemispheric interactions in stroke patients during motor control is an important clinical neuroscience quest that may provide important clues for neurorehabilitation. In stroke patients bilateral overactivation in both hemispheres has been interpreted as a poor prognostic indicator of functional recovery. In contrast, ipsilesional patterns have been linked with better motor outcomes. Aim We investigated the pathophysiology of hemispheric interactions during limb movement without and with contralateral restraint, to mimic the effects of constraint-induced movement therapy. We used neuroimaging to probe brain activity with such a movement-dependent interhemispheric modulation paradigm. Methods We used a functional magnetic resonance imaging block design during which the plegic/paretic upper limb was recruited/mobilized to perform unilateral arm elevation, as a function of presence versus absence of contralateral limb restriction (n = 20, with balanced left/right lesion sites). Results Analysis of 10 right hemispheric stroke participants yielded bilateral sensorimotor cortex activation in all movement phases in contrast with the unilateral dominance seen in the 10 left hemispheric stroke participants. Superimposition of contralateral restriction led to a prominent shift from activation to deactivation response patterns, in particular in cortical and basal ganglia motor areas in right hemispheric stroke. Left hemispheric stroke was, in general, characterized by reduced activation patterns, even in the absence of restriction, which induced additional cortical silencing. Conclusion The observed hemispheric-dependent activation/deactivation shifts is novel and these pathophysiological observations suggest short-term neuroplasticity that may be useful for hemisphere-tailored neurorehabilitation.

  15. The hemispherical deflector analyser revisited

    Energy Technology Data Exchange (ETDEWEB)

    Benis, E.P. [Institute of Electronic Structure and Laser, P.O. Box 1385, 71110 Heraklion, Crete (Greece)], E-mail: benis@iesl.forth.gr; Zouros, T.J.M. [Institute of Electronic Structure and Laser, P.O. Box 1385, 71110 Heraklion, Crete (Greece); Department of Physics, University of Crete, P.O. Box 2208, 71003 Heraklion, Crete (Greece)

    2008-04-15

    Using the basic spectrometer trajectory equation for motion in an ideal 1/r potential derived in Eq. (101) of part I [T.J.M. Zouros, E.P. Benis, J. Electron Spectrosc. Relat. Phenom. 125 (2002) 221], the operational characteristics of a hemispherical deflector analyser (HDA) such as dispersion, energy resolution, energy calibration, input lens magnification and energy acceptance window are investigated from first principles. These characteristics are studied as a function of the entry point R{sub 0} and the nominal value of the potential V(R{sub 0}) at entry. Electron-optics simulations and actual laboratory measurements are compared to our theoretical results for an ideal biased paracentric HDA using a four-element zoom lens and a two-dimensional position sensitive detector (2D-PSD). These results should be of particular interest to users of modern HDAs utilizing a PSD.

  16. The hemispherical deflector analyser revisited

    International Nuclear Information System (INIS)

    Benis, E.P.; Zouros, T.J.M.

    2008-01-01

    Using the basic spectrometer trajectory equation for motion in an ideal 1/r potential derived in Eq. (101) of part I [T.J.M. Zouros, E.P. Benis, J. Electron Spectrosc. Relat. Phenom. 125 (2002) 221], the operational characteristics of a hemispherical deflector analyser (HDA) such as dispersion, energy resolution, energy calibration, input lens magnification and energy acceptance window are investigated from first principles. These characteristics are studied as a function of the entry point R 0 and the nominal value of the potential V(R 0 ) at entry. Electron-optics simulations and actual laboratory measurements are compared to our theoretical results for an ideal biased paracentric HDA using a four-element zoom lens and a two-dimensional position sensitive detector (2D-PSD). These results should be of particular interest to users of modern HDAs utilizing a PSD

  17. Increasing Northern Hemisphere water deficit

    Science.gov (United States)

    McCabe, Gregory J.; Wolock, David M.

    2015-01-01

    A monthly water-balance model is used with CRUTS3.1 gridded monthly precipitation and potential evapotranspiration (PET) data to examine changes in global water deficit (PET minus actual evapotranspiration) for the Northern Hemisphere (NH) for the years 1905 through 2009. Results show that NH deficit increased dramatically near the year 2000 during both the cool (October through March) and warm (April through September) seasons. The increase in water deficit near 2000 coincides with a substantial increase in NH temperature and PET. The most pronounced increases in deficit occurred for the latitudinal band from 0 to 40°N. These results indicate that global warming has increased the water deficit in the NH and that the increase since 2000 is unprecedented for the 1905 through 2009 period. Additionally, coincident with the increase in deficit near 2000, mean NH runoff also increased due to increases in P. We explain the apparent contradiction of concurrent increases in deficit and increases in runoff.

  18. Right hemispheric reversible cerebral vasoconstriction syndrome in a patient with left hemispheric partial seizures.

    Science.gov (United States)

    Perez, Gina S; McCaslin, Justin; Shamim, Sadat

    2017-04-01

    We report a right-handed 19-year-old girl who developed reversible cerebral vasoconstriction syndrome (RCVS) lateralized to the right hemisphere with simultaneous new-onset left hemispheric seizures. RCVS, typically more diffuse, was lateralized to one of the cerebral hemispheres.

  19. Homotopic Language Reorganization in the Right Hemisphere after Early Left Hemisphere Injury

    Science.gov (United States)

    Tivarus, Madalina E.; Starling, Sarah J.; Newport, Elissa L.; Langfitt, John T.

    2012-01-01

    To determine the areas involved in reorganization of language to the right hemisphere after early left hemisphere injury, we compared fMRI activation patterns during four production and comprehension tasks in post-surgical epilepsy patients with either left (LH) or right hemisphere (RH) speech dominance (determined by Wada testing) and healthy…

  20. Ultrasound in Space Medicine

    Science.gov (United States)

    Dulchavsky, Scott A.; Sargsyan, A.E.

    2009-01-01

    This slide presentation reviews the use of ultrasound as a diagnostic tool in microgravity environments. The goals of research in ultrasound usage in space environments are: (1) Determine accuracy of ultrasound in novel clinical conditions. (2) Determine optimal training methodologies, (3) Determine microgravity associated changes and (4) Develop intuitive ultrasound catalog to enhance autonomous medical care. Also uses of Ultrasound technology in terrestrial applications are reviewed.

  1. The Southern Oscillation and northern hemisphere temperature variability

    International Nuclear Information System (INIS)

    Ropelewski, C.F.; Halpert, M.S.

    1990-01-01

    The Southern Oscillation (SO) is the best defined and understood mode of interannual climate variability. The extreme phases of the SO have been identified with global-scale variations in the atmosphere/ocean circulation system and with the modulation of monsoon precipitation on the global scale. While SO-related precipitation has been the subject of several studies, the magnitude of the SO-related temperature variability on the global scale has not been well documented. In this paper the authors provide an estimate of the SO-related temperature variability in the context of monitoring global warming related to the increase in greenhouse gases. This analysis suggested that traditional time series of hemispheric and global temperature anomalies for the calendar year may confuse interannual temperature variability associated with the SO and perceived climate trend. Analyses based on calendar-year data are likely to split the effects of the SO-related temperature variability over two years. The Northern Hemisphere cold season (october through March) time series may be more appropriate to separate the SO-related effects on the hemispheric temperature from other modes of variability. mean interannual temperature anomaly differences associated with the extremes of the So are estimated to be 0.2 C for the October-to-March season in the Northern Hemisphere. In areas directly linked to the SO, the mean interannual differences amount to over 0.5 C. The So cannot account for all the variability in the hemispheric times series of surface temperature estimates, but the SO signal must be properly accounted for if these time series are to be understood

  2. Personality, Hemispheric Dominance, and Cognitive Style.

    Science.gov (United States)

    Hylton, Jaime; Hartman, Steve E.

    1997-01-01

    Shows that 154 medical students and 526 undergraduates (samples treated separately) who were judged left- or right-hemisphere dominant (by the Hemispheric Mode Indicator) were found to have very different personalities (as measured by the Myers-Briggs Type Indicator). Considers some of the practical ramifications of the psychometric overlap of…

  3. Interaction of cerebral hemispheres and artistic thinking

    Science.gov (United States)

    Nikolaenko, Nikolay N.

    1998-07-01

    Study of drawings by patients with local lesions of the right or left hemisphere allows to understand how artistic thinking is supported by brain structures. The role of the right hemisphere is significant at the early stage of creative process. The right hemisphere is a generator of nonverbal visuo-spatial thinking. It operates with blurred nonverbal images and arrange them in a visual space. With the help of iconic signs the right hemisphere reflects the world and creates perceptive visual standards which are stored in the long-term right hemisphere memory. The image, which appeared in the `inner' space, should be transferred into a principally different language, i.e. a left hemispheric sign language. This language operates with a number of discrete units, logical succession and learned grammar rules. This process can be explained by activation (information) transfer from the right hemisphere to the left one. Thus, natural and spontaneous creative process, which is finished by a conscious effort, can be understood as an activation impulse transfer from the right hemisphere to the left one and back.

  4. Hypothalamic digoxin, hemispheric chemical dominance and sarcoidosis.

    Science.gov (United States)

    Ravi Kumar, A; Kurup, Parameswara Achutha

    2004-06-01

    The isoprenoid pathway produces three key metabolites: endogenous digoxin (membrane sodium-potassium ATPase inhibitor, immunomodulator and regulator of neurotransmitter/amino acid transport), dolichol (regulates N-glycosylation of proteins) and ubiquinone (free radical scavenger). The role of the isoprenoid pathway in the pathogenesis of sarcoidosis in relation to hemispheric dominance was studied. The isoprenoid pathway-related cascade was assessed in patients with systemic sarcoidosis with pulmonary involvement. The pathway was also assessed in patients with right hemispheric, left hemispheric and bihemispheric dominance for comparison to find out the role of hemispheric dominance in the pathogenesis of sarcoidosis. In patients with sarcoidosis there was elevated digoxin synthesis, increased dolichol and glycoconjugate levels and low ubiquinone and elevated free radical levels. There was also an increase in tryptophan catabolites and a reduction in tyrosine catabolites. There was an increase in the cholesterol:phospholipid ratio and a reduction in the glycoconjugate level of red blood cell (RBC) membrane in this group of patients. The same biochemical patterns were obtained in individuals with right hemispheric dominance. In individuals with left hemispheric dominance the patterns were reversed. Endogenous digoxin, by activating the calcineurin signal transduction pathway of T cells, can contribute to immune activation in sarcoidosis. An altered glycoconjugate metabolism can lead to the generation of endogenous self-glycoprotein antigens in the lung as well as other tissues. Increased free radical generation can also lead to immune activation. The role of a dysfunctional isoprenoid pathway and endogenous digoxin in the pathogenesis of sarcoidosis in relation to right hemispheric chemical dominance is discussed. All the patients with sarcoidosis were right-handed/left hemispheric dominant according to the dichotic listening test, but their biochemical patterns

  5. Climate change induced by Southern Hemisphere desertification

    Science.gov (United States)

    Wang, Ye; Yan, Xiaodong

    2017-12-01

    Some 10-20% of global dry-lands are already degraded, and the ongoing desertification threatens the world's poorest populations. Studies on desertification effects are essential for humans to adapt to the environmental challenges posed by desertification. Given the importance of the much larger southern ocean to the global climate and the Southern Hemisphere (SH) climate changes in phase with those in the north, the biogeophysical effects of the SH desertification on climate are assessed using an Earth system model of intermediate complexity, MPM-2. This analysis focuses on differences in climate among the averages of simulations with desert expansion in different latitude bands by year 2000. The localized desertification causes significant global changes in temperature and precipitation as well as surface albedo. On the global scale, cooling dominates the SH desertification effects. However, the biogeophysical effects are most significant in regions with desertification, and the cooling is also prominent in northern mid-latitudes. Desert expansion in 15°-30°S reveals statistically most significant cooling and increased precipitation over the forcing regions during spring. The global and regional scale responses from desertification imply the climate teleconnection and address the importance of the effects from the SH which are contingent on the location of the forcing. Our study indicates that biogeophysical mechanisms of land cover changes in the SH need to be accounted for in the assessment of land management options especially for latitude band over 15°-30°S.

  6. A Preliminary fMRI Study of a Novel Self-Paced Written Fluency Task: Observation of Left-Hemispheric Activation, and Increased Frontal Activation in Late vs. Early Task Phases

    Directory of Open Access Journals (Sweden)

    Laleh eGolestanirad

    2015-03-01

    Full Text Available Neuropsychological tests of verbal fluency are very widely used to characterize impaired cognitive function. For clinical neuroscience studies and potential medical applications, measuring the brain activity that underlies such tests with functional magnetic resonance imaging (fMRI is of significant interest - but a challenging proposition because overt speech can cause signal artifacts, which tend to worsen as the duration of speech tasks becomes longer. In a novel approach, we present the group brain activity of 12 subjects who performed a self-paced written version of phonemic fluency using fMRI-compatible tablet technology that recorded responses and provided task-related feedback on a projection screen display, over long-duration task blocks (60 s. As predicted, we observed robust activation in the left anterior inferior and medial frontal gyri, consisting with previously reported results of verbal fluency tasks which established the role of these areas in strategic word retrieval. In addition, the number of words produced in the late phase (last 30 s of written phonemic fluency was significantly less (p < 0.05 than the number produced in the early phase (first 30 s. Activation during the late phase vs. the early phase was also assessed from the first 20 s and last 20 s of task performance, which eliminated the possibility that the sluggish hemodynamic response from the early phase would affect the activation estimates of the late phase. The last 20 s produced greater activation maps covering extended areas in bilateral precuneus, cuneus, middle temporal gyrus, insula, middle frontal gyrus and cingulate gyrus. Among them, greater activation was observed in the bilateral middle frontal gyrus (Brodmann area BA 9 and cingulate gyrus (BA 24, 32 likely as part of the initiation, maintenance, and shifting of attentional resources.

  7. HEMISPHERIC CENTER FOR ENVIRONMENTAL TECHNOLOGY

    Energy Technology Data Exchange (ETDEWEB)

    M.A. Ebadian

    1999-10-31

    The Deactivation and Decommissioning (D&D) Technology Assessment Program (TAP) was developed to provide detailed, comparable data for environmental technologies and to disseminate this data to D&D professionals in a manner that will facilitate the review and selection of technologies to perform decontamination and decommissioning. The objectives for this project include the following: Determine technology needs through review of the Site Technology Coordination Group (STCG) information and other applicable websites and needs databases; Perform a detailed review of industries that perform similar activities as those required in D&D operations to identify additional technologies; Define the technology assessment program for characterization and waste management problem sets; Define the data management program for characterization, dismantlement, and waste management problem sets; Evaluate baseline and innovative technologies under standard test conditions at Florida International University's Hemispheric Center for Environmental Technology (FIU-HCET) and other locations and collect data in the areas of performance, cost, health and safety, operations and maintenance, and primary and secondary waste generation; Continue to locate, verify, and incorporate technology performance data from other sources into the multimedia information system; and Develop the conceptual design for a dismantlement technology decision analysis tool for dismantlement technologies.

  8. MRI and contrast-enhanced ultrasound imaging for evaluation of focal irreversible electroporation treatment: results from a phase I-II study in patients undergoing IRE followed by radical prostatectomy

    International Nuclear Information System (INIS)

    Bos, Willemien van den; Bruin, D.M. de; Randen, A. van; Engelbrecht, M.R.W.; Postema, A.W.; Muller, B.G.; Zondervan, P.J.; Laguna Pes, M.P.; Reijke, T.M. de; Rosette, J.J.M.C.H. de la; Varkarakis, I.M.; Skolarikos, A.; Savci-Heijink, C.D.; Jurhill, R.R.; Wijkstra, H.

    2016-01-01

    Irreversible electroporation (IRE) is an ablative therapy with a low side-effect profile in prostate cancer. The objective was: 1) To compare the volumetric IRE ablation zone on grey-scale transrectal ultrasound (TRUS), contrast-enhanced ultrasound (CEUS) and multiparametric MRI (mpMRI) with histopathology findings; 2) To determine a reliable imaging modality to visualize the IRE ablation effects accurately. A prospective phase I-II study was performed in 16 patients scheduled for radical prostatectomy (RP). IRE of the prostate was performed 4 weeks before RP. Prior to, and 4 weeks after the IRE treatment, imaging was performed by TRUS, CEUS, and mpMRI. 3D-analysis of the ablation volumes on imaging and on H and E-stained whole-mount sections was performed. The volumes were compared and the correlation was calculated. Evaluation of the imaging demonstrated that with T2-weighted MRI, dynamic contrast enhanced (DCE) MRI, and CEUS, effects of IRE are visible. T2MRI and CEUS closely match the volumes on histopathology (Pearson correlation r = 0.88 resp. 0.80). However, IRE is not visible with TRUS. mpMRI and CEUS are appropriate for assessing IRE effects and are the most feasible imaging modalities to visualize IRE ablation zone. The imaging is concordant with results of histopathological examination. (orig.)

  9. Prostate Ultrasound

    Medline Plus

    Full Text Available ... phased array) receiver coil. top of page Additional Information and Resources RTAnswers.org Radiation Therapy for Prostate ... Send us your feedback Did you find the information you were looking for? Yes No Please type ...

  10. The effect of cognitive load on hemispheric asymmetries in true and false memory.

    Science.gov (United States)

    Tat, Michael J; Azuma, Tamiko

    2016-01-01

    Studies examining hemispheric asymmetries in false memory have shown that the right hemisphere (RH) is more susceptible to false memories compared to the left hemisphere (LH). Theories suggest that hemispheric asymmetries in true and false memory may be due to differences in representational coding and the use of top-down mechanisms in each hemisphere. In the current study, the Deese-Roediger-McDermott false memory paradigm was used in conjunction with divided visual field presentation to examine the role of top-down mechanisms in hemispheric asymmetries of true and false memory. In Experiment 1, participants studied lists of related words while completing secondary cognitive load tasks. In Experiment 2, the secondary tasks were administered during memory retrieval instead of memory encoding. Results revealed that cognitive loads imposed during the study phase influenced veridical memory in the LH more than the RH, but cognitive loads imposed during retrieval did not influence veridical memory in either hemisphere. Surprisingly, false memory rates were not influenced by cognitive loads and were higher in the LH. These data provide evidence that, at least for veridical memory, top-down control mechanisms are used more readily for the encoding of information into memory in the LH compared to the RH.

  11. Numerical simulation of heat transfer and phase change during freezing of potatoes with different shapes at the presence or absence of ultrasound irradiation

    Science.gov (United States)

    Kiani, Hossein; Sun, Da-Wen

    2018-03-01

    As novel processes such as ultrasound assisted heat transfer are emerged, new models and simulations are needed to describe these processes. In this paper, a numerical model was developed to study the freezing process of potatoes. Different thermal conductivity models were investigated, and the effect of sonication was evaluated on the convective heat transfer in a fluid to the particle heat transfer system. Potato spheres and sticks were the geometries researched, and the effect of different processing parameters on the results were studied. The numerical model successfully predicted the ultrasound assisted freezing of various shapes in comparison with experimental data of the process. The model was sensitive to processing parameters variation (sound intensity, duty cycle, shape, etc.) and could accurately simulate the freezing process. Among the thermal conductivity correlations studied, de Vries and Maxwell models gave closer estimations. The maximum temperature difference was obtained for the series equation that underestimated the thermal conductivity. Both numerical and experimental data confirmed that an optimum condition of intensity and duty cycle is needed for reducing the freezing time, as increasing the intensity, increased the heat transfer rate and sonically heating rate, simultaneously, that acted against each other.

  12. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... size, shape and consistency (whether the object is solid or filled with fluid). In medicine, ultrasound is ... ultrasound, measures the direction and speed of blood cells as they move through vessels. The movement of ...

  13. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... procedure? Ultrasound examinations can help to diagnose a variety of conditions and to assess organ damage following ... the Ultrasound-Guided Breast Biopsy page . diagnose a variety of heart conditions, including valve problems and congestive ...

  14. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... 3-D) ultrasound that formats the sound wave data into 3-D images. A Doppler ultrasound study ... at these links. About Us | Contact Us | FAQ | Privacy | Terms of Use | Links | Site Map Copyright © 2018 ...

  15. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... 3-D) ultrasound that formats the sound wave data into 3-D images. A Doppler ultrasound study ... to do the scanning. The transducer is a small hand-held device that resembles a microphone, attached ...

  16. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... in infections With knowledge about the speed and volume of blood flow gained from a Doppler ultrasound ... the body while other areas, especially air-filled lungs, are poorly suited for ultrasound. top of page ...

  17. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... flat sections of the body. Advancements in ultrasound technology include three-dimensional (3-D) ultrasound that formats ... color picture. It can also convert blood flow information into a distinctive sound that can be heard ...

  18. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... flat sections of the body. Advancements in ultrasound technology include three-dimensional (3-D) ultrasound that formats ... care physician, or to the physician or other healthcare provider who requested the exam. Usually, the referring ...

  19. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... flat sections of the body. Advancements in ultrasound technology include three-dimensional (3-D) ultrasound that formats ... at these links. About Us | Contact Us | FAQ | Privacy | Terms of Use | Links | Site Map Copyright © 2018 ...

  20. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... top of page What are the benefits vs. risks? Benefits Most ultrasound scanning is noninvasive (no needles ... procedures such as needle biopsies and fluid aspiration. Risks For standard diagnostic ultrasound , there are no known ...

  1. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... ultrasound. top of page How does the procedure work? Ultrasound imaging is based on the same principles ... move through vessels. The movement of blood cells causes a change in pitch of the reflected sound ...

  2. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... ultrasound. top of page How does the procedure work? Ultrasound imaging is based on the same principles ... requested the exam. Usually, the referring physician or health care provider will share the results with you. ...

  3. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... flat sections of the body. Advancements in ultrasound technology include three-dimensional (3-D) ultrasound that formats ... possible charges you will incur. Web page review process: This Web page is reviewed regularly by a ...

  4. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... need to be returned to the transducer for analysis. Ultrasound has difficulty penetrating bone and, therefore, can ... ultrasound procedure View full size with caption Pediatric Content Some imaging tests and treatments have special pediatric ...

  5. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... flat sections of the body. Advancements in ultrasound technology include three-dimensional (3-D) ultrasound that formats ... legs, neck and/or brain (in infants and children) or within various body organs such as the ...

  6. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... flat sections of the body. Advancements in ultrasound technology include three-dimensional (3-D) ultrasound that formats ... sonography is performed using the same transducer. Rarely, young children may need to be sedated in order ...

  7. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... image. Ultrasound examinations do not use ionizing radiation (as used in x-rays ), thus there is no ... structure and movement of the body's internal organs, as well as blood flowing through blood vessels. Ultrasound ...

  8. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... testing. image the breasts and guide biopsy of breast cancer ( see the Ultrasound-Guided Breast Biopsy page . diagnose ... Ultrasound is the preferred imaging modality for the diagnosis and monitoring of pregnant women and their unborn ...

  9. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... Ultrasound is the preferred imaging modality for the diagnosis and monitoring of pregnant women and their unborn ... needle biopsies and fluid aspiration. Risks For standard diagnostic ultrasound , there are no known harmful effects on ...

  10. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z General Ultrasound Ultrasound ... computer or television monitor. The image is created based on the amplitude (loudness), frequency (pitch) and time ...

  11. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... ultrasound. top of page How does the procedure work? Ultrasound imaging is based on the same principles ... more extensive exams may take up to an hour. When the examination is complete, you may be ...

  12. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... Imaging? Ultrasound waves are disrupted by air or gas; therefore ultrasound is not an ideal imaging technique ... with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes ...

  13. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... may produce minimal discomfort. If a Doppler ultrasound study is performed, you may actually hear pulse-like sounds that change in pitch as the blood flow is monitored and measured. Most ultrasound examinations ...

  14. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... ultrasound. top of page How does the procedure work? Ultrasound imaging is based on the same principles ... have special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media Angioplasty and ...

  15. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... ultrasound. top of page How does the procedure work? Ultrasound imaging is based on the same principles ... about this beforehand and be made aware of food and drink restrictions that may be needed prior ...

  16. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... Ultrasound is safe, noninvasive, and does not use ionizing radiation. This procedure requires little to no special preparation. ... create an image. Ultrasound examinations do not use ionizing radiation (as used in x-rays ), thus there is ...

  17. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... flat sections of the body. Advancements in ultrasound technology include three-dimensional (3-D) ultrasound that formats ... American College of Radiology (ACR) and the Radiological Society of North America (RSNA), comprising physicians with expertise ...

  18. Medical Ultrasound Imaging.

    Science.gov (United States)

    Hughes, Stephen

    2001-01-01

    Explains the basic principles of ultrasound using everyday physics. Topics include the generation of ultrasound, basic interactions with material, and the measurement of blood flow using the Doppler effect. (Author/MM)

  19. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... ultrasound. top of page How does the procedure work? Ultrasound imaging is based on the same principles ... the transducer is pressed against the skin, it directs small pulses of inaudible, high-frequency sound waves ...

  20. Hemispheric resource limitations in comprehending ambiguous pictures.

    Science.gov (United States)

    White, H; Minor, S W

    1990-03-01

    Ambiguous pictures (Roschach inkblots) were lateralized for 100 msec vs. 200 msec to the right and left hemispheres (RH and LH) of 32 normal right-handed males who determined which of two previously presented words (an accurate or inaccurate one) better described the inkblot. Over the first 32 trials, subjects receiving each stimulus exposure duration were less accurate when the hemisphere receiving the stimulus also controlled the hand used to register a keypress response (RH-left hand and LH-right hand trials) than when hemispheric resources were shared, i.e., when one hemisphere controlled stimulus processing and the other controlled response programming. These differences were eliminated when the 32 trials were repeated.

  1. Onsite-effects of dual-hemisphere versus conventional single-hemisphere transcranial direct current stimulation

    Science.gov (United States)

    Kwon, Yong Hyun; Jang, Sung Ho

    2012-01-01

    We performed functional MRI examinations in six right-handed healthy subjects. During functional MRI scanning, transcranial direct current stimulation was delivered with the anode over the right primary sensorimotor cortex and the cathode over the left primary sensorimotor cortex using dual-hemispheric transcranial direct current stimulation. This was compared to a cathode over the left supraorbital area using conventional single-hemispheric transcranial direct current stimulation. Voxel counts and blood oxygenation level-dependent signal intensities in the right primary sensorimotor cortex regions were estimated and compared between the two transcranial direct current stimulation conditions. Our results showed that dual-hemispheric transcranial direct current stimulation induced greater cortical activities than single-hemispheric transcranial direct current stimulation. These findings suggest that dual-hemispheric transcranial direct current stimulation may provide more effective cortical stimulation than single-hemispheric transcranial direct current stimulation. PMID:25624815

  2. Significance of Hemispheric Security for Mexico

    Science.gov (United States)

    2003-04-07

    La Seguridad Internacional, la Nueva Geopolitica Continental y Mexico ,” Seminario Internacional sobre Misiones de Paz, Seguridad y Defensa, Rio de...USAWC STRATEGY RESEARCH PROJECT SIGNIFICANCE OF HEMISPHERIC SECURITY FOR MEXICO by LTC Enrique Garcia Jaramillo Cavalry, Mexican Army COL Joseph R...xx-xx-2002 to xx-xx-2003 4. TITLE AND SUBTITLE Significance of Hemispheric Security for Mexico Unclassified 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c

  3. Hypothalamic digoxin, hemispheric chemical dominance, and sleep.

    Science.gov (United States)

    Kurup, Ravi Kumar; Kurup, Parameswara Achutha

    2003-04-01

    The isoprenoid path way produces endogenous digoxin, a substance that can regulate neurotransmitter and amino acid transport. Digoxin synthesis and neurotransmitter patterns were assessed in individuals with chronic insomnia. The patterns were compared in those with right hemispheric and left hemispheric dominance. The activity of HMG GoA reductase and serum levels of digoxin, magnesium, tryptophan catabolites, and tyrosine catabolites were measured in individuals with chronic insomnia and in individuals with differing hemispheric dominance. Digoxin synthesis was increased with upregulated tryptophan catabolism (increased levels of serotonin, strychnine, and nicotine), and downregulated tyrosine catabolism (decreased levels of dopamine, noradrenaline, and morphine) in those with chronic insomnia and right hemispheric chemical dominance. Digoxin synthesis was reduced with downregulated tryptophan catabolism (decreased levels of serotonin, strychnine, and nicotine) and upregulated tyrosine catabolism (increased levels of dopamine, noradrenaline, and morphine) in those with normal sleep patterns and left hemispheric chemical dominance. Hypothalamic digoxin plays a central role in the regulation of sleep behavior. Hemispheric chemical dominance in relation to digoxin status is also crucial.

  4. Hypothalamic digoxin, hemispheric chemical dominance, and spirituality.

    Science.gov (United States)

    Kurup, Ravi Kumar; Kurup, Parameswara Achutha

    2003-03-01

    The isoprenoid pathway was assessed in atheistic and spiritually inclined individuals. The pathway was also assessed in individuals with differing hemispheric dominance to assess whether hemispheric dominance has a correlation with spiritual and atheistic tendency. HMG CoA reductase activity, serum digoxin, RBC membrane Na(+)-K+ ATPase activity, serum magnesium, and tyrosine/tryptophan catabolic patterns were assessed in spiritual/atheistic individuals and in those differing hemispheric dominance. In spiritually-inclined individuals, there was increased digoxin synthesis, decreased membrane Na(+)-K+ ATPase activity, increased tryptophan catabolites (serotonin, quinolinic acid, and nicotine), and decreased tyrosine catabolites (dopamine, noradrenaline, and morphine). The pattern in spiritually-inclined individuals correlated with right hemispheric chemical dominance. In atheistic individuals there was decreased digoxin synthesis, increased membrane Na(+)-K+ ATPase activity, decreased tryptophan catabolities (serotonin, quinolinic acid, and nicotine), and increased tyrosine catabolites (dopamine, noradrenaline, and morphine). This pattern in atheistic individuals correlated with that obtained in left hemispheric chemical dominance. Hemispheric chemical dominance and hypothalamic digoxin could regulate the predisposition to spirituality or atheism.

  5. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... transducer sends out high-frequency sound waves (that the human ear cannot hear) into the body and then ... ultrasound , there are no known harmful effects on humans. top of page What are the limitations of General Ultrasound Imaging? Ultrasound waves are ...

  6. Clinical diagnostic ultrasound

    International Nuclear Information System (INIS)

    Barnett, E.; Morley, P.

    1986-01-01

    This textbook on diagnostic ultrasound covers the main systems, with emphasis being placed on the clinical application of diagnostic ultrasound in everyday practice. It provides not only a textbook for postgraduates (particularly FRCR candidates), but also a reference work for practitioners of clinical ultrasound and clinicians generally

  7. The potential of high intensity focused ultrasound (HIFU) combine phase-sensitive optical coherence tomography (PhS-OCT) for diseases diagnosis, treatment and monitoring

    Science.gov (United States)

    Zhou, Kanheng; Wang, Yan; Feng, Kairui; Li, Chunhui; Huang, Zhihong

    2018-02-01

    HIFU is a truly noninvasive, acoustic therapeutic technique that utilizes high intensity acoustic field in the focus to kill the targeted tissue for disease treatment purpose. The mechanical properties of targeted tissue changes before and after treatment, and this change can be accurately detected by shear wave elastography. Hence, shear wave elastography is usually used for monitoring HIFU treatment asynchronously. To improve the low spatial resolution in ultrasound shear wave elastography, and to perform diseases diagnosis, treatment and monitoring in the same system, a new setup that combines HIFU and PhS-OCT system was proposed in this study. This proposed setup could do 1) HIFU treatment when the transducer works at high energy level, 2) ultrasound induced shear wave optical coherence elastography for HIFU treatment asynchronous monitoring when the transducer works at low energy level. Ex-vivo bovine liver tissue was treated at the same energy level for different time (0s, 1s, 5s, 9s) in this research. Elastography was performed on the lesion area of the sample after HIFU treatment, and the elastogram was reconstructed by the time of flight time method. The elastogram results clearly show the boundary of HIFU lesion area and surrounding normal tissue, even for 1s treatment time. And the average elasticity of the lesion grows linearly as the treatment time increases. Combined with OCT needle probe, the proposed method has a large potential not only to be used for superficial diseases treatment, but also to be used for high-precision-demanded diseases treatment, e.g. nervous disease treatment.

  8. Hypothalamic digoxin, hemispheric chemical dominance, and creativity.

    Science.gov (United States)

    Kurup, Ravi Kumar; Kurup, Parameswara Achutha

    2003-04-01

    The human hypothalamus produces an endogenous membrane Na(+)-K+ ATPase inhibitor, digoxin, which regulates neuronal transmission. The digoxin status and neurotransmitter patterns were studied in creative and non-creative individuals, as well as in individuals with differing hemispheric dominance, in order to find out the role of cerebral dominance in this respect. The activity of HMG CoA reductase and serum levels of digoxin, magnesium, tryptophan catabolites, and tyrosine catabolites were measured in creative/non-creative individuals, and in individuals with differing hemispheric dominance. In creative individuals there was increased digoxin synthesis, decreased membrane Na(+)-K+ ATPase activity, increased tryptophan catabolites (serotonin, quinolinic acid, and nicotine), and decreased tyrosine catabolites (dopamine, noradrenaline, and morphine). The pattern in creative individuals correlated with right hemispheric dominance. In non-creative individuals there was decreased digoxin synthesis, increased membrane Na(+)-K+ ATPase activity, decreased tryptophan catabolites (serotonin, quinolinic acid, and nicotine), and increased tyrosine catabolites (dopamine, noradrenaline, and morphine). This pattern in non-creative individuals correlated with that obtained in left hemispheric chemical dominance. Hemispheric chemical dominance and hypothalamic digoxin could regulate the predisposition to creative tendency.

  9. Successful Completion of the Pilot Phase of a Randomized Controlled Trial Comparing Sentinel Lymph Node Biopsy to No Further Axillary Staging in Patients with Clinical T1-T2 N0 Breast Cancer and Normal Axillary Ultrasound.

    Science.gov (United States)

    Cyr, Amy E; Tucker, Natalia; Ademuyiwa, Foluso; Margenthaler, Julie A; Aft, Rebecca L; Eberlein, Timothy J; Appleton, Catherine M; Zoberi, Imran; Thomas, Maria A; Gao, Feng; Gillanders, William E

    2016-08-01

    Axillary surgery is not considered therapeutic in patients with clinical T1-T2 N0 breast cancer. The importance of axillary staging is eroding in an era in which tumor biology, as defined by biomarker and gene expression profile, is increasingly important in medical decision making. We hypothesized that axillary ultrasound (AUS) is a noninvasive alternative to sentinel lymph node biopsy (SLNB), and AUS could replace SLNB without compromising patient care. Patients with clinical T1-T2 N0 breast cancer and normal AUS were eligible for enrollment. Subjects were randomized to no further axillary staging (arm 1) vs SLNB (arm 2). Descriptive statistics were used to describe the results of the pilot phase of the randomized controlled trial. Sixty-eight subjects were enrolled in the pilot phase of the trial (34 subjects in arm 1, no further staging; 32 subjects in arm 2, SLNB; and 2 subjects voluntarily withdrew from the trial). The median age was 61 years (range 40 to 80 years) in arm 1 and 59 years (range 31 to 81 years) in arm 2, and there were no significant clinical or pathologic differences between the arms. Median follow-up was 17 months (range 1 to 32 months). The negative predictive value (NPV) of AUS for identification of clinically significant axillary disease (>2.0 mm) was 96.9%. No axillary recurrences have been observed in either arm. Successful completion of the pilot phase of the randomized controlled trial confirms the feasibility of the study design, and provides prospective evidence supporting the ability of AUS to exclude clinically significant disease in the axilla. The results provide strong support for a phase 2 randomized controlled trial. Copyright © 2016 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

  10. Sustained knowledge acquisition among Rwandan physicians participating in six-month ultrasound training program

    Directory of Open Access Journals (Sweden)

    P.C. Henwood*

    2013-12-01

    Conclusions: Trainees demonstrated significant knowledge improvement after an intensive introductory ultrasound course, which increased through the training program. Mean OSCE scores remained above 80% throughout the course. Participants in an ultrasound training program with an initial training phase and periodic skill reinforcement can acquire and retain ultrasound knowledge and scanning skills.

  11. ERP evidence for hemispheric asymmetries in exemplar-specific explicit memory access.

    Science.gov (United States)

    Küper, Kristina; Zimmer, Hubert D

    2015-11-02

    The right cerebral hemisphere (RH) appears to be more effective in representing visual objects as distinct exemplars than the left hemisphere (LH) which is presumably biased towards coding objects at the level of abstract prototypes. As of yet, relatively little is known about the role that asymmetries in exemplar-specificity play at the level of explicit memory retrieval. In the present study, we addressed this issue by examining hemispheric asymmetries in the putative event-related potential (ERP) correlates of familiarity (FN400) and recollection (LPC). In an incidental study phase, pictures of familiar objects were presented centrally. At test, participants performed a memory inclusion task on identical repetitions and different exemplars of study items as well as new items which were presented in only one visual hemifield using the divided visual field technique. With respect to familiarity, we observed exemplar-specific FN400 old/new effects that were more pronounced for identical repetitions than different exemplars, irrespective of the hemisphere governing initial stimulus processing. In contrast, LPC old/new effects were subject to some hemispheric asymmetries indicating that exemplar-specific recollection was more extensive in the RH than in the LH. This further corroborates the idea that hemispheric asymmetries should not be generalized but need to be distinguished not only in different domains but also at different levels of processing. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Decadal variability and metastability in the Southern Hemisphere

    Science.gov (United States)

    O'Kane, Terence; Risbey, James; Franzke, Christian; Horenko, Illia; Monselesan, Didier

    2014-05-01

    An examination of systematic changes in the metastability of the southern hemisphere 500hPa circulation is performed using both cluster analysis techniques and split flow blocking indices. The cluster methodology is a purely data-driven approach for parametrisation whereby a multi-scale approximation to non-stationary dynamical processes is achieved through optimal sequences of locally stationary fast Vector Auto-Regressive Factor (VARX) processes and some slow (or persistent) hidden process switching between them. Comparison is made with blocking indices commonly used in weather forecasting and climate analysis to identify dynamically relevant metastable regimes in the 500hPa circulation in both reanalysis and AMIP model data sets. Our analysis characterises the metastable regime in both reanalysis and model data sets prior to 1978 as positive and negative phases of a hemispheric mid-latitude blocking state with the Southern Annular Mode (SAM) associated with a transition state. Post 1978, SAM emerges as a true metastable state replacing the negative phase of the hemispheric blocking pattern. The hidden state frequency of occurrences exhibits strong trends. The blocking pattern dominates in the early 1980s then gradually decreases. There is a corresponding increase in the SAM frequency of occurrence. This trend is largely evident in the reanalysis summer and spring but was not evident in the AMIP data set. Non-stationary cluster analysis was then further used to identify the Southern Oceans response to the systematic changes in the mid-latitude atmospheric circulation and identify dynamical regimes associated with subsurface thermocline anomalies which were found to teleconnect the Pacific and Atlantic regions of the Antarctic Circumpolar Current (ACC).

  13. Trace determination of five triazole fungicide residues in traditional Chinese medicine samples by dispersive solid-phase extraction combined with ultrasound-assisted dispersive liquid-liquid microextraction and UHPLC-MS/MS.

    Science.gov (United States)

    Ma, Shuping; Yuan, Xucan; Zhao, Pengfei; Sun, Hong; Ye, Xiu; Liang, Ning; Zhao, Longshan

    2017-08-01

    A novel and reliable method for determination of five triazole fungicide residues (triadimenol, tebuconazole, diniconazole, flutriafol, and hexaconazol) in traditional Chinese medicine samples was developed using dispersive solid-phase extraction combined with ultrasound-assisted dispersive liquid-liquid microextraction before ultra-high performance liquid chromatography with tandem mass spectrometry. The clean up of the extract was conducted using dispersive solid-phase extraction by directly adding sorbents into the extraction solution, followed by shaking and centrifugation. After that, a mixture of 400 μL trichloromethane (extraction solvent) and 0.5 mL of the above supernatant was injected rapidly into water for the dispersive liquid-liquid microextraction procedure. The factors affecting the extraction efficiency were optimized. Under the optimum conditions, the calibration curves showed good linearity in the range of 2.0-400 (tebuconazole, diniconazole, and hexaconazole) and 4.0-800 ng/g (triadimenol and flutriafol) with the regression coefficients higher than 0.9958. The limit of detection and limit of quantification for the present method were 0.5-1.1 and 1.8-4.0 ng/g, respectively. The recoveries of the target analytes ranged from 80.2 to 103.2%. The proposed method has been successfully applied to the analysis of five triazole fungicides in traditional Chinese medicine samples, and satisfactory results were obtained. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Quality control culture of diagnostic ultrasound parameters

    International Nuclear Information System (INIS)

    Andam, A.A.B; Addison, E.C.K.; Aggry-Smith, S.; Nani, E.K.

    2003-01-01

    A phantom, consisting of two phases, has been designed and constructed to mimic the human body. The phase one phantom was designed to mimic a a surface lesion in the human body and the phase two phantom designed to mimic a section of the whole body. Ultrasound scans of the phantom were acquired for various material in the phantom at six hospitals in Kumasi, Ghana. A linear array transducer with parallel beams having a convex probe and a 3.5 MHz ultrasound frequency were used to carry out the experiment. It was observed that the depth of penetration of ultrasound, which constitutes the maximum depth of visualization or sensitivity, is determined by the frequency of the transducer, the attenuation of the medium being imaged and the system settings. Uniformity and linearity of the machines investigated were found to be within clinically acceptable standards. Spatial resolution, comprising axial and lateral resolutions, was observed to be satisfactory for the machines tested. It was observed that lateral resolution improved with the narrowing of the beam width. The ultrasound scanners at the selected hospitals were found to be operating at the expected level of performance. This work highlights the importance of putting in place a locally based mechanism for quality control of diagnostic ultrasound machines (author)

  15. Abnormal inter- and intra-hemispheric integration in male paranoid schizophrenia: a graph-theoretical analysis.

    Science.gov (United States)

    Chen, Jianhuai; Yao, Zhijian; Qin, Jiaolong; Yan, Rui; Hua, Lingling; Lu, Qing

    2015-06-25

    The human brain is a complex network of regions that are structurally interconnected by white matter (WM) tracts. Schizophrenia (SZ) can be conceptualized as a disconnection syndrome characterized by widespread disconnections in WM pathways. To assess whether or not anatomical disconnections are associated with disruption of the topological properties of inter- and intra-hemispheric networks in SZ. We acquired the diffusion tensor imaging data from 24 male patients with paranoid SZ during an acute phase of their illness and from 24 healthy age-matched male controls. The brain FA-weighted (fractional anisotropy-weighted) structural networks were constructed and the inter- and intra-hemispheric integration was assessed by estimating the average characteristic path lengths (CPLs) between and within the left and right hemisphere networks. The mean CPLs for all 18 inter-and intra-hemispheric CPLs assessed were longer in the SZ patient group than in the control group, but only some of these differences were significantly different: the CPLs for the overall inter-hemispheric and the left and right intra-hemispheric networks; the CPLs for the interhemisphere subnetworks of the frontal lobes, temporal lobes, and subcortical structures; and the CPL for the intra- frontal subnetwork in the right hemisphere. Among the 24 patients, the CPL of the inter-frontal subnetwork was positively associated with negative symptom severity, but this was the only significant result among 72 assessed correlations, so it may be a statistical artifact. Our findings suggest that the integrity of intra- and inter-hemispheric WM tracts is disrupted in males with paranoid SZ, supporting the brain network disconnection model (i.e., the (')connectivity hypothesis(')) of schizophrenia. Larger studies with less narrowly defined samples of individuals with schizophrenia are needed to confirm these results.

  16. Combined ultrasound and MR imaging to guide focused ultrasound therapies in the brain

    Science.gov (United States)

    Arvanitis, Costas D.; Livingstone, Margaret S.; McDannold, Nathan

    2013-07-01

    Several emerging therapies with potential for use in the brain, harness effects produced by acoustic cavitation—the interaction between ultrasound and microbubbles either generated during sonication or introduced into the vasculature. Systems developed for transcranial MRI-guided focused ultrasound (MRgFUS) thermal ablation can enable their clinical translation, but methods for real-time monitoring and control are currently lacking. Acoustic emissions produced during sonication can provide information about the location, strength and type of the microbubble oscillations within the ultrasound field, and they can be mapped in real-time using passive imaging approaches. Here, we tested whether such mapping can be achieved transcranially within a clinical brain MRgFUS system. We integrated an ultrasound imaging array into the hemisphere transducer of the MRgFUS device. Passive cavitation maps were obtained during sonications combined with a circulating microbubble agent at 20 targets in the cingulate cortex in three macaques. The maps were compared with MRI-evident tissue effects. The system successfully mapped microbubble activity during both stable and inertial cavitation, which was correlated with MRI-evident transient blood-brain barrier disruption and vascular damage, respectively. The location of this activity was coincident with the resulting tissue changes within the expected resolution limits of the system. While preliminary, these data clearly demonstrate, for the first time, that it is possible to construct maps of stable and inertial cavitation transcranially, in a large animal model, and under clinically relevant conditions. Further, these results suggest that this hybrid ultrasound/MRI approach can provide comprehensive guidance for targeted drug delivery via blood-brain barrier disruption and other emerging ultrasound treatments, facilitating their clinical translation. We anticipate that it will also prove to be an important research tool that will

  17. Combined ultrasound and MR imaging to guide focused ultrasound therapies in the brain

    International Nuclear Information System (INIS)

    Arvanitis, Costas D; McDannold, Nathan; Livingstone, Margaret S

    2013-01-01

    Several emerging therapies with potential for use in the brain, harness effects produced by acoustic cavitation—the interaction between ultrasound and microbubbles either generated during sonication or introduced into the vasculature. Systems developed for transcranial MRI-guided focused ultrasound (MRgFUS) thermal ablation can enable their clinical translation, but methods for real-time monitoring and control are currently lacking. Acoustic emissions produced during sonication can provide information about the location, strength and type of the microbubble oscillations within the ultrasound field, and they can be mapped in real-time using passive imaging approaches. Here, we tested whether such mapping can be achieved transcranially within a clinical brain MRgFUS system. We integrated an ultrasound imaging array into the hemisphere transducer of the MRgFUS device. Passive cavitation maps were obtained during sonications combined with a circulating microbubble agent at 20 targets in the cingulate cortex in three macaques. The maps were compared with MRI-evident tissue effects. The system successfully mapped microbubble activity during both stable and inertial cavitation, which was correlated with MRI-evident transient blood–brain barrier disruption and vascular damage, respectively. The location of this activity was coincident with the resulting tissue changes within the expected resolution limits of the system. While preliminary, these data clearly demonstrate, for the first time, that it is possible to construct maps of stable and inertial cavitation transcranially, in a large animal model, and under clinically relevant conditions. Further, these results suggest that this hybrid ultrasound/MRI approach can provide comprehensive guidance for targeted drug delivery via blood–brain barrier disruption and other emerging ultrasound treatments, facilitating their clinical translation. We anticipate that it will also prove to be an important research tool that

  18. A novel approach for preparation of micrometer-sized, monodisperse dimple and hemispherical polystyrene particles.

    Science.gov (United States)

    Tanaka, Takuya; Komatsu, Yoshifumi; Fujibayashi, Teruhisa; Minami, Hideto; Okubo, Masayoshi

    2010-03-16

    Micrometer-sized, monodisperse dimple and hemispherical polystyrene (PS) particles were successfully prepared by heating (55-70 degrees C) of spherical PS particles dispersed in methanol/water media (40/60 to 80/20, w/w) in the presence of decane droplets, and subsequent cooling down to room temperature. Decane was absorbed by the PS particles during the heating process. Decane-absorbed PS particles phase-separated into PS and decane phases in the inside during the cooling process, and eventually dimple and/or hemispherical particles were formed by removal of the decane phase from phase-separated PS/decane particles by evaporation. The size of the dimple, which is determined by the volume of decane phase-separated from decane-absorbed PS particles during the cooling process, increased with increases in the heating temperature and the methanol content.

  19. Right hemisphere grey matter structure and language outcomes in chronic left hemisphere stroke

    Science.gov (United States)

    Xing, Shihui; Lacey, Elizabeth H.; Skipper-Kallal, Laura M.; Jiang, Xiong; Harris-Love, Michelle L.; Zeng, Jinsheng

    2016-01-01

    The neural mechanisms underlying recovery of language after left hemisphere stroke remain elusive. Although older evidence suggested that right hemisphere language homologues compensate for damage in left hemisphere language areas, the current prevailing theory suggests that right hemisphere engagement is ineffective or even maladaptive. Using a novel combination of support vector regression-based lesion-symptom mapping and voxel-based morphometry, we aimed to determine whether local grey matter volume in the right hemisphere independently contributes to aphasia outcomes after chronic left hemisphere stroke. Thirty-two left hemisphere stroke survivors with aphasia underwent language assessment with the Western Aphasia Battery-Revised and tests of other cognitive domains. High-resolution T1-weighted images were obtained in aphasia patients and 30 demographically matched healthy controls. Support vector regression-based multivariate lesion-symptom mapping was used to identify critical language areas in the left hemisphere and then to quantify each stroke survivor’s lesion burden in these areas. After controlling for these direct effects of the stroke on language, voxel-based morphometry was then used to determine whether local grey matter volumes in the right hemisphere explained additional variance in language outcomes. In brain areas in which grey matter volumes related to language outcomes, we then compared grey matter volumes in patients and healthy controls to assess post-stroke plasticity. Lesion–symptom mapping showed that specific left hemisphere regions related to different language abilities. After controlling for lesion burden in these areas, lesion size, and demographic factors, grey matter volumes in parts of the right temporoparietal cortex positively related to spontaneous speech, naming, and repetition scores. Examining whether domain general cognitive functions might explain these relationships, partial correlations demonstrated that grey matter

  20. Right hemisphere grey matter structure and language outcomes in chronic left hemisphere stroke.

    Science.gov (United States)

    Xing, Shihui; Lacey, Elizabeth H; Skipper-Kallal, Laura M; Jiang, Xiong; Harris-Love, Michelle L; Zeng, Jinsheng; Turkeltaub, Peter E

    2016-01-01

    The neural mechanisms underlying recovery of language after left hemisphere stroke remain elusive. Although older evidence suggested that right hemisphere language homologues compensate for damage in left hemisphere language areas, the current prevailing theory suggests that right hemisphere engagement is ineffective or even maladaptive. Using a novel combination of support vector regression-based lesion-symptom mapping and voxel-based morphometry, we aimed to determine whether local grey matter volume in the right hemisphere independently contributes to aphasia outcomes after chronic left hemisphere stroke. Thirty-two left hemisphere stroke survivors with aphasia underwent language assessment with the Western Aphasia Battery-Revised and tests of other cognitive domains. High-resolution T1-weighted images were obtained in aphasia patients and 30 demographically matched healthy controls. Support vector regression-based multivariate lesion-symptom mapping was used to identify critical language areas in the left hemisphere and then to quantify each stroke survivor's lesion burden in these areas. After controlling for these direct effects of the stroke on language, voxel-based morphometry was then used to determine whether local grey matter volumes in the right hemisphere explained additional variance in language outcomes. In brain areas in which grey matter volumes related to language outcomes, we then compared grey matter volumes in patients and healthy controls to assess post-stroke plasticity. Lesion-symptom mapping showed that specific left hemisphere regions related to different language abilities. After controlling for lesion burden in these areas, lesion size, and demographic factors, grey matter volumes in parts of the right temporoparietal cortex positively related to spontaneous speech, naming, and repetition scores. Examining whether domain general cognitive functions might explain these relationships, partial correlations demonstrated that grey matter

  1. Heat transfer from internally heated hemispherical pools

    International Nuclear Information System (INIS)

    Gabor, J.D.; Ellsion, P.G.; Cassulo, J.C.

    1980-01-01

    Experiments were conducted on heat transfer from internally heated ZnSO 4 -H 2 O pools to the walls of hemispherical containers. This experimental technique provides data for a heat transfer system that has to date been only theoretically treated. Three different sizes of copper hemispherical containers were used: 240, 280, 320 mm in diameter. The pool container served both as a heat transfer surface and as an electrode. The opposing electrode was a copper disk, 50 mm in diameter located at the top of the pool in the center. The top surface of the pool was open to the atmosphere

  2. Unilateral Opening of Rat Blood-Brain Barrier Assisted by Diagnostic Ultrasound Targeted Microbubbles Destruction.

    Science.gov (United States)

    Xu, Yali; Cui, Hai; Zhu, Qiong; Hua, Xing; Xia, Hongmei; Tan, Kaibin; Gao, Yunhua; Zhao, Jing; Liu, Zheng

    2016-01-01

    Objective. Blood-brain barrier (BBB) is a key obstacle that prevents the medication from blood to the brain. Microbubble-enhanced cavitation by focused ultrasound can open the BBB and proves to be valuable in the brain drug delivery. The study aimed to explore the feasibility, efficacy, and safety of unilateral opening of BBB using diagnostic ultrasound targeted microbubbles destruction in rats. Methods. A transtemporal bone irradiation of diagnostic ultrasound and intravenous injection of lipid-coated microbubbles were performed at unilateral hemisphere. Pathological changes were monitored. Evans Blue extravasation grades, extraction from brain tissue, and fluorescence optical density were quantified. Lanthanum nitrate was traced by transmission electron microscopy. Results. After diagnostic ultrasound mediated microbubbles destruction, Evans Blue extravasation and fluorescence integrated optical density were significantly higher in the irradiated hemisphere than the contralateral side (all p ultrasound-exposed hemisphere (4 ± 1, grade 2) while being invisible in the control side. Lanthanum nitrate tracers leaked through interendothelial cleft and spread to the nerve fiber existed in the irradiation side. Conclusions. Transtemporal bone irradiation under DUS mediated microbubble destruction provides us with a more accessible, safer, and higher selective BBB opening approach in rats, which is advantageous in brain targeted drugs delivery.

  3. Unilateral Opening of Rat Blood-Brain Barrier Assisted by Diagnostic Ultrasound Targeted Microbubbles Destruction

    Directory of Open Access Journals (Sweden)

    Yali Xu

    2016-01-01

    Full Text Available Objective. Blood-brain barrier (BBB is a key obstacle that prevents the medication from blood to the brain. Microbubble-enhanced cavitation by focused ultrasound can open the BBB and proves to be valuable in the brain drug delivery. The study aimed to explore the feasibility, efficacy, and safety of unilateral opening of BBB using diagnostic ultrasound targeted microbubbles destruction in rats. Methods. A transtemporal bone irradiation of diagnostic ultrasound and intravenous injection of lipid-coated microbubbles were performed at unilateral hemisphere. Pathological changes were monitored. Evans Blue extravasation grades, extraction from brain tissue, and fluorescence optical density were quantified. Lanthanum nitrate was traced by transmission electron microscopy. Results. After diagnostic ultrasound mediated microbubbles destruction, Evans Blue extravasation and fluorescence integrated optical density were significantly higher in the irradiated hemisphere than the contralateral side (all p<0.01. Erythrocytes extravasations were demonstrated in the ultrasound-exposed hemisphere (4±1, grade 2 while being invisible in the control side. Lanthanum nitrate tracers leaked through interendothelial cleft and spread to the nerve fiber existed in the irradiation side. Conclusions. Transtemporal bone irradiation under DUS mediated microbubble destruction provides us with a more accessible, safer, and higher selective BBB opening approach in rats, which is advantageous in brain targeted drugs delivery.

  4. Children's (Pediatric) Abdominal Ultrasound Imaging

    Medline Plus

    Full Text Available ... child's abdominal ultrasound examination. Doppler ultrasound , also called color Doppler ultrasonography, is a special ultrasound technique that ... and processes the sounds and creates graphs or color pictures that represent the flow of blood through ...

  5. Children's (Pediatric) Abdominal Ultrasound Imaging

    Medline Plus

    Full Text Available ... Physician Resources Professions Site Index A-Z Children's (Pediatric) Ultrasound - Abdomen Children’s (pediatric) ultrasound imaging of the ... abdomen using ultrasound. View full size with caption Pediatric Content Some imaging tests and treatments have special ...

  6. Children's (Pediatric) Abdominal Ultrasound Imaging

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Children's (Pediatric) Ultrasound - Abdomen Children’s (pediatric) ultrasound imaging of the ... abdomen using ultrasound. View full size with caption Pediatric Content Some imaging tests and treatments have special ...

  7. Children's (Pediatric) Abdominal Ultrasound Imaging

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z Children's (Pediatric) Ultrasound - Abdomen Children’s (pediatric) ultrasound imaging of ... 30 minutes. top of page What will my child experience during and after the procedure? Ultrasound examinations ...

  8. The Indian ultrasound paradox

    OpenAIRE

    Akbulut-Yuksel, Mevlude; Rosenblum, Daniel

    2012-01-01

    The liberalization of the Indian economy in the 1990s made prenatal ultrasound technology affordable and available to a large fraction of the population. As a result, ultrasound use amongst pregnant women rose dramatically in many parts of India. This paper provides evidence on the consequences of the expansion of prenatal ultrasound use on sex-selection. We exploit state-by-cohort variation in ultrasound use in India as a unique quasi-experiment. We find that sex-selective abortion of female...

  9. Focused ultrasound in ophthalmology

    Directory of Open Access Journals (Sweden)

    Silverman RH

    2016-09-01

    Full Text Available Ronald H Silverman1,2 1Department of Ophthalmology, Columbia University Medical Center, 2F.L. Lizzi Center for Biomedical Engineering, Riverside Research, New York, NY, USA Abstract: The use of focused ultrasound to obtain diagnostically significant information about the eye goes back to the 1950s. This review describes the historical and technological development of ophthalmic ultrasound and its clinical application and impact. Ultrasound, like light, can be focused, which is crucial for formation of high-resolution, diagnostically useful images. Focused, single-element, mechanically scanned transducers are most common in ophthalmology. Specially designed transducers have been used to generate focused, high-intensity ultrasound that through thermal effects has been used to treat glaucoma (via cilio-destruction, tumors, and other pathologies. Linear and annular transducer arrays offer synthetic focusing in which precise timing of the excitation of independently addressable array elements allows formation of a converging wavefront to create a focus at one or more programmable depths. Most recently, linear array-based plane-wave ultrasound, in which the array emits an unfocused wavefront and focusing is performed solely on received data, has been demonstrated for imaging ocular anatomy and blood flow. While the history of ophthalmic ultrasound extends back over half-a-century, new and powerful technologic advances continue to be made, offering the prospect of novel diagnostic capabilities. Keywords: ophthalmic ultrasound, ultrasound biomicroscopy (UBM, high-intensity focused ultrasound (HIFU, ultrafast imaging, Doppler imaging 

  10. Automatic Ultrasound Scanning

    DEFF Research Database (Denmark)

    Moshavegh, Ramin

    on the user adjustments on the scanner interface to optimize the scan settings. This explains the huge interest in the subject of this PhD project entitled “AUTOMATIC ULTRASOUND SCANNING”. The key goals of the project have been to develop automated techniques to minimize the unnecessary settings...... on the scanners, and to improve the computer-aided diagnosis (CAD) in ultrasound by introducing new quantitative measures. Thus, four major issues concerning automation of the medical ultrasound are addressed in this PhD project. They touch upon gain adjustments in ultrasound, automatic synthetic aperture image...

  11. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... internal organs, as well as blood flowing through blood vessels. Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions. ...

  12. Point of Care Ultrasound

    DEFF Research Database (Denmark)

    Dietrich, Christoph F; Goudie, Adrian; Chiorean, Liliana

    2017-01-01

    Over the last decade, the use of portable ultrasound scanners has enhanced the concept of point of care ultrasound (PoC-US), namely, "ultrasound performed at the bedside and interpreted directly by the treating clinician." PoC-US is not a replacement for comprehensive ultrasound, but rather allows...... and critical care medicine, cardiology, anesthesiology, rheumatology, obstetrics, neonatology, gynecology, gastroenterology and many other applications. In the future, PoC-US will be more diverse than ever and be included in medical student training....

  13. Ultrasound skin tightening.

    Science.gov (United States)

    Minkis, Kira; Alam, Murad

    2014-01-01

    Ultrasound skin tightening is a noninvasive, nonablative method that allows for energy deposition into the deep dermal and subcutaneous tissue while avoiding epidermal heating. Ultrasound coagulation is confined to arrays of 1-mm(3) zones that include the superficial musculoaponeurotic system and connective tissue. This technology gained approval from the Food and Drug Administration as the first energy-based skin "lifting" device, specifically for lifting lax tissue on the neck, submentum, and eyebrows. Ultrasound has the unique advantage of direct visualization of treated structures during treatment. Ultrasound is a safe and efficacious treatment for mild skin tightening and lifting. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Investment in the Western Hemisphere energy market

    International Nuclear Information System (INIS)

    Gillam, P.J.

    1991-01-01

    This paper reports that the main characteristics of Western Hemisphere energy markets are well known to those in the energy industry. The United States sits in the northern half of the hemisphere, importing more and more oil from the rest of the world. Brazil, with a market one-tenth of the size of the United Sates, sits in the southern half of the hemisphere, importing less and less oil from the rest of the world. Venezuela sits in the center with an eye to the future as a long-term player in the world petroleum industry. Venezuela has 6 or 7 percent of the world's known conventional petroleum reserves, plus an uncountable bitumen resource which is now being commercialized as Orimulsion, a low-emission substitute for coal. The United States is circled by major producing countries with smaller exports, such as Mexico and Canada, and there are smaller producing or consuming countries of which Colombia is the largest exporter and Argentian the largest importer. The United States dominates the numbers. Half of British Petroleum's (BP) investments have been in the energy industry of the Western Hemisphere. We are maintaining that proportion, but opportunities are becoming more difficult to find

  15. Hemispheric differences in the mesostriatal dopaminergic system

    Directory of Open Access Journals (Sweden)

    Ilana eMolochnikov

    2014-06-01

    Full Text Available The mesostriatal dopaminergic system, which comprises the mesolimbic and the nigrostriatal pathways, plays a major role in neural processing underlying motor and limbic functions. Multiple reports suggest that these processes are influenced by hemispheric differences in striatal dopamine (DA levels, DA turnover and its receptor activity. Here, we review studies which measured the concentration of DA and its metabolites to examine the relationship between DA imbalance and animal behavior under different conditions. Specifically, we assess evidence in support of endogenous, inter-hemispheric DA imbalance; determine whether the known anatomy provides a suitable substrate for this imbalance; examine the relationship between DA imbalance and animal behavior; and characterize the symmetry of the observed inter-hemispheric laterality in the nigrostriatal and the mesolimbic DA systems. We conclude that many studies provide supporting evidence for the occurrence of experience-dependent endogenous DA imbalance which is controlled by a dedicated regulatory/compensatory mechanism. Additionally, it seems that the link between DA imbalance and animal behavior is better characterized in the nigrostriatal than in the mesolimbic system. Nonetheless, a variety of brain and behavioral manipulations demonstrate that the nigrostriatal system displays symmetrical laterality whereas the mesolimbic system displays asymmetrical laterality which supports hemispheric specialization in rodents. The reciprocity of the relationship between DA imbalance and animal behavior (i.e. the capacity of animal training to alter DA imbalance for prolonged time periods remains controversial, however, if confirmed, may provide a valuable noninvasive therapeutic means for treating abnormal DA imbalance.

  16. Forest carbon sinks in the Northern Hemisphere

    Science.gov (United States)

    Christine L. Goodale; Michael J. Apps; Richard A. Birdsey; Christopher B. Field; Linda S. Heath; Richard A. Houghton; Jennifer C. Jenkins; Gundolf H. Kohlmaier; Werner Kurz; Shirong Liu; Gert-Jan Nabuurs; Sten Nilsson; Anatoly Z. Shvidenko

    2002-01-01

    There is general agreement that terrestrial systems in the Northern Hemisphere provide a significant sink for atmospheric CO2; however, estimates of the magnitude and distribution of this sink vary greatly. National forest inventories provide strong, measurement-based constraints on the magnitude of net forest carbon uptake. We brought together...

  17. A vision of graded hemispheric specialization.

    Science.gov (United States)

    Behrmann, Marlene; Plaut, David C

    2015-11-01

    Understanding the process by which the cerebral hemispheres reach their mature functional organization remains challenging. We propose a theoretical account in which, in the domain of vision, faces and words come to be represented adjacent to retinotopic cortex by virtue of the need to discriminate among homogeneous exemplars. Orthographic representations are further constrained to be proximal to typically left-lateralized language-related information to minimize connectivity length between visual and language areas. As reading is acquired, orthography comes to rely more heavily (albeit not exclusively) on the left fusiform region to bridge vision and language. Consequently, due to competition from emerging word representations, face representations that were initially bilateral become lateralized to the right fusiform region (albeit, again, not exclusively). We review recent research that describes constraints that give rise to this graded hemispheric arrangement. We then summarize empirical evidence from a variety of studies (behavioral, evoked response potential, functional imaging) across different populations (children, adolescents, and adults; left handers and individuals with developmental dyslexia) that supports the claims that hemispheric lateralization is graded rather than binary and that this graded organization emerges dynamically over the course of development. Perturbations of this system either during development or in adulthood provide further insights into the principles governing hemispheric organization. © 2015 New York Academy of Sciences.

  18. Ultrasound-guided high dose rate conformal brachytherapy boost in prostate cancer: treatment description and preliminary results of a phase I/II clinical trial

    Energy Technology Data Exchange (ETDEWEB)

    Stromberg, Jannifer; Martinez, Alvaro; Gonzalez, Jose; Edmundson, Gregory; Ohanian, Neshan; Vicini, Frank; Hollander, Jay; Gustafson, Gary; Spencer, William; Di, Yan; Brabbins, Donald

    1995-08-30

    Purpose: To improve results for locally advanced prostate cancer, a prospective clinical trial of concurrent external beam irradiation and fractionated iridium-192 (Ir-192) high dose rate (HDR) conformal boost brachytherapy was initiated. Methods and Materials: Between November 1991 and February 1994, 99 implants were performed on 33 patients with prostatic adenocarcinoma at William Beaumont Hospital. Using AJCC staging criteria, 9 patients had T2b tumors, 17 patients had T2c tumors, and 7 patients had T3 disease. Patients were treated with (a) 45.6 Gy whole pelvis external irradiation and (b) three HDR fractions of 5.5 Gy each (18 patients) or 6 Gy each (15 patients) to the prostate. Transperineal needle implants using real-time ultrasound guidance with interactive on-line isodose distributions were performed on an outpatient basis during weeks 1, 2, and 3 of external irradiation. Acute toxicity was scored using the Radiation Therapy Oncology Group (RTOG) morbidity grading system. Results: This technique of concurrent external pelvic irradiation and conformal HDR brachytherapy was well tolerated. No significant intraoperative or perioperative complications occurred. Three patients (9%) experienced Grade 3 acute toxicity (two dysuria and one diarrhea). All toxicities were otherwise Grades 1 or 2 and were primarily as expected from pelvic external irradiation. Persistent implant-related toxicities included Grades 1-2 perineal pain (12%) and hematospermia (15%). Median follow-up time was 13 months. Serum prostatic-specific antigen (PSA) levels normalized in 91% of patients (29 out of 32) within 1-14 months (median 2.8 months) after irradiation. PSA levels were progressively decreasing in the other three patients at last measurement. Prospectively planned prostatic rebiopsies done at 18 months in the first 10 patients were negative in 9 out of 10 (90%). Conclusions: Acute toxicity has been acceptable with this unique approach using conformal high dose rate Ir-192

  19. Venous catheterization with ultrasound navigation

    International Nuclear Information System (INIS)

    Kasatkin, A. A.; Nigmatullina, A. R.; Urakov, A. L.

    2015-01-01

    By ultrasound scanning it was determined that respiratory movements made by chest of healthy and sick person are accompanied by respiratory chest rise of internal jugular veins. During the exhalation of an individual diameter of his veins increases and during the breath it decreases down to the complete disappearing if their lumen. Change of the diameter of internal jugular veins in different phases can influence significantly the results of vein puncture and cauterization in patients. The purpose of this research is development of the method increasing the efficiency and safety of cannulation of internal jugular veins by the ultrasound visualization. We suggested the method of catheterization of internal jugular veins by the ultrasound navigation during the execution of which the puncture of venous wall by puncture needle and the following conduction of J-guide is carried out at the moment of patient’s exhalation. This method decreases the risk of complications development during catheterization of internal jugular vein due to exclusion of perforating wound of vein and subjacent tissues and anatomical structures

  20. Venous catheterization with ultrasound navigation

    Energy Technology Data Exchange (ETDEWEB)

    Kasatkin, A. A., E-mail: ant-kasatkin@yandex.ru; Nigmatullina, A. R. [Izhevsk State Medical Academy, Kommunarov street, 281, Izhevsk, Russia, 426034 (Russian Federation); Urakov, A. L., E-mail: ant-kasatkin@yandex.ru [Institute of Mechanics Ural Branch of Russian Academy of Sciences, T.Baramzinoy street 34, Izhevsk, Russia, 426067, Izhevsk (Russian Federation); Izhevsk State Medical Academy, Kommunarov street, 281, Izhevsk, Russia, 426034 (Russian Federation)

    2015-11-17

    By ultrasound scanning it was determined that respiratory movements made by chest of healthy and sick person are accompanied by respiratory chest rise of internal jugular veins. During the exhalation of an individual diameter of his veins increases and during the breath it decreases down to the complete disappearing if their lumen. Change of the diameter of internal jugular veins in different phases can influence significantly the results of vein puncture and cauterization in patients. The purpose of this research is development of the method increasing the efficiency and safety of cannulation of internal jugular veins by the ultrasound visualization. We suggested the method of catheterization of internal jugular veins by the ultrasound navigation during the execution of which the puncture of venous wall by puncture needle and the following conduction of J-guide is carried out at the moment of patient’s exhalation. This method decreases the risk of complications development during catheterization of internal jugular vein due to exclusion of perforating wound of vein and subjacent tissues and anatomical structures.

  1. Children's (Pediatric) Abdominal Ultrasound Imaging

    Medline Plus

    Full Text Available ... through blood vessels. Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions. Children's (pediatric) abdominal ultrasound imaging produces pictures ...

  2. A Simple Method for the Simultaneous Determination of Pharmaceuticals and Personal Care Products in River Sediment by Ultrasound-Assisted Extraction Followed by Solid-Phase Microextraction Coupled with Gas Chromatography-Mass Spectrometry.

    Science.gov (United States)

    Díaz, Alejandro; Peña-Alvarez, Araceli

    2017-10-01

    A simple method was developed using ultrasound-assisted extraction (UAE) combined with solid-phase microextraction (SPME) coupled with gas chromatography-mass spectrometry (GC-MS) for the simultaneous determination of eight different pharmaceuticals and personal care products (PPCPs) (ibuprofen, 2-benzyl-4-chlorophenol, naproxen, triclosan, ketoprofen, diclofenac, bisphenol A and estrone) in river sediment. UAE conditions were optimized involving extraction variables such as extraction solvent, extraction time, sample amount, extraction temperature, pH and salt addition. A 100 mg of sediment was extracted by optimized UAE process using 7 mL deionized water (pH 3) + 1% methanol as solvent, room temperature and 1 min extraction at 70% of amplitude. A 5 mL of supernatant was subsequently extracted by SPME; the extracted analytes were derivatized on fiber in head-space mode with N-methyl-N-(tertbutyldimethylsilyl) trifluoroacetamide and then analyzed by GC-MS. The developed method was evaluated by testing: precision (CV 0.98), recoveries (56-108%), limits of detection (simple and environmentally friendly, and provides straightforward analyses of these trace organic pollutants in sediment samples. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. Halloysite nanotubes as a solid sorbent in ultrasound-assisted dispersive micro solid-phase extraction for the determination of bismuth in water samples using high-resolution continuum source graphite-furnace atomic absorption spectrometry

    Science.gov (United States)

    Krawczyk-Coda, Magdalena

    2017-03-01

    In this research, a simple, accurate, and inexpensive preconcentration procedure was developed for the determination of bismuth in water samples, using high-resolution continuum source graphite furnace atomic absorption spectrometry (HR CS GFAAS). During the preconcentration step, halloysite nanotubes (HNTs) were used as a solid sorbent in ultrasound-assisted dispersive micro solid-phase extraction (USA DMSPE). The influence of the pH of the sample solution, amount of HNTs, and extraction time, as well as of the main parameters of HR CS GFAAS, on absorbance was investigated. The limit of detection was 0.005 μg L- 1. The preconcentration factor achieved for bismuth was 32. The relative standard deviation (RSD) was 4%. The accuracy of this method was validated by analyses of NIST SRM 1643e (Trace elements in water) and TMDA-54.5 (A high level fortified sample for trace elements) certified reference materials. The measured bismuth contents in these certified reference materials were in satisfactory agreement with the certified values according to the t-test for a 95% confidence level. The proposed method has been successfully applied to the determination of bismuth in five different real water samples (seawater, lake water, river water, stream water and rain water).

  4. Ultrasound-assisted leaching-dispersive solid-phase extraction followed by liquid-liquid microextraction for the determination of polybrominated diphenyl ethers in sediment samples by gas chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Fontana, Ariel R; Lana, Nerina B; Martinez, Luis D; Altamirano, Jorgelina C

    2010-06-30

    Ultrasound-assisted leaching-dispersive solid-phase extraction followed by dispersive liquid-liquid microextraction (USAL-DSPE-DLLME) technique has been developed as a new analytical approach for extracting, cleaning up and preconcentrating polybrominated diphenyl ethers (PBDEs) from sediment samples prior gas chromatography-tandem mass spectrometry (GC-MS/MS) analysis. In the first place, PBDEs were leached from sediment samples by using acetone. This extract was cleaned-up by DSPE using activated silica gel as sorbent material. After clean-up, PBDEs were preconcentrated by using DLLME technique. Thus, 1 mL acetone extract (disperser solvent) and 60 microL carbon tetrachloride (extraction solvent) were added to 5 mL ultrapure water and a DLLME technique was applied. Several variables that govern the proposed technique were studied and optimized. Under optimum conditions, the method detection limits (MDLs) of PBDEs calculated as three times the signal-to-noise ratio (S/N) were within the range 0.02-0.06 ng g(-1). The relative standard deviations (RSDs) for five replicates were or =0.9991. Validation of the methodology was carried out by standard addition method at two concentration levels (0.25 and 1 ng g(-1)) and by comparing with a reference Soxhlet technique. Recovery values were > or =80%, which showed a satisfactory robustness of the analytical methodology for determination of low PBDEs concentration in sediment samples. Copyright 2010 Elsevier B.V. All rights reserved.

  5. Onsite-effects of dual-hemisphere versus conventional single-hemisphere transcranial direct current stimulation

    OpenAIRE

    Kwon, Yong Hyun; Jang, Sung Ho

    2012-01-01

    We performed functional MRI examinations in six right-handed healthy subjects. During functional MRI scanning, transcranial direct current stimulation was delivered with the anode over the right primary sensorimotor cortex and the cathode over the left primary sensorimotor cortex using dual-hemispheric transcranial direct current stimulation. This was compared to a cathode over the left supraorbital area using conventional single-hemispheric transcranial direct current stimulation. Voxel coun...

  6. Development of Flexible Capacitive Ultrasound Transducers and the Use of Ultrasound for Bone Repair

    Science.gov (United States)

    Wentzell, Scott A.

    Ultrasound is a widely applicable technique for therapy in the biomedical arena. However, conventional ultrasound transducers are not conducive for non-planar surfaces. Therefore, we developed flexible transducers capable of performing ultrasound and evaluated their use in biomedical applications. Flexible capacitive ultrasound transducers based on micrometer-thick dielectric tapes were developed and fabricated. These transducers were able to be made by hand at low-cost while still demonstrating good tolerances in center operating frequency. Intensities of up to 120 mW/cm2 were recorded and operation was dependent upon the applied AC and DC voltages along with the thickness of the dielectric insulation. These capacitive ultrasound transducers were used to stimulate MC3T3-E1 murine osteoblast cells to investigate the effects of low-frequency ultrasound on osteogenic gene expression and anabolic signaling pathways. After stimulation by 94.5 kHz continuous wave ultrasound for 20 minutes, significant increases in the activation of the Wnt signaling pathway and concentration of intracellular calcium were observed. Daily stimulation by ultrasound showed a trend of increased osteogenic gene expression across the phases of matrix deposition, maturation and calcification by osteoblasts. Finally, the heating of osteoblasts for stimulating osteoclastogenic responses was investigated. The application of increased temperatures of 42 and 47 degrees Celsius for 5 minutes showed significant increases in the RANKL/OPG ratio in media conditioned by osteoblasts. However, the altered RANKL/OPG ratio was not able to generate increases in osteoclastogenesis for RAW 264.7 murine macrophage cells culture in the condition media. This was possibly due to high overall osteoprotegerin expression, or unwanted inducement of M1 and M2 macrophage activation in the cell population. The overall work of this thesis demonstrates the development of novel capacitive transducers. These conformable

  7. General Ultrasound Imaging

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z General Ultrasound Ultrasound imaging ...

  8. Medical ultrasound imaging

    DEFF Research Database (Denmark)

    Jensen, Jørgen Arendt

    2007-01-01

    The paper gives an introduction to current medical ultrasound imaging systems. The basics of anatomic and blood flow imaging are described. The properties of medical ultrasound and its focusing are described, and the various methods for two- and three-dimensional imaging of the human anatomy...

  9. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... to image by ultrasound because greater amounts of tissue attenuate (weaken) the sound waves as they pass deeper into the body and need to be returned to the transducer for analysis. Ultrasound has difficulty penetrating bone and, therefore, can only see the outer surface ...

  10. Ultrasound: Bladder (For Parents)

    Science.gov (United States)

    ... If You Have Questions Print en español Ultrasonido: vejiga What It Is A bladder ultrasound is a safe and painless test that ... Exam: Voiding Cystourethrogram (VCUG) Ultrasound: Renal (Kidneys, Ureters, Bladder) Urinary ... only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995- The Nemours Foundation. All ...

  11. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... women and their unborn babies. Ultrasound provides real-time imaging, making it a good tool for guiding minimally invasive procedures such as needle biopsies and fluid aspiration. Risks For standard diagnostic ultrasound , there are no known harmful effects on humans. top of page What are the ...

  12. Choosing words: left hemisphere, right hemisphere, or both? Perspective on the lateralization of word retrieval

    Science.gov (United States)

    Ries, Stephanie K.; Dronkers, Nina F.; Knight, Robert T.

    2015-01-01

    Language is considered to be one of the most lateralized human brain functions. Left hemisphere dominance for language has been consistently confirmed in clinical and experimental settings and constitutes one of the main axioms of neurology and neuroscience. However, functional neuroimaging studies are finding that the right hemisphere also plays a role in diverse language functions. Critically, the right hemisphere may also compensate for the loss or degradation of language functions following extensive stroke-induced damage to the left hemisphere. Here, we review studies that focus on our ability to choose words as we speak. Although fluidly performed in individuals with intact language, this process is routinely compromised in aphasic patients. We suggest that parceling word retrieval into its sub-processes—lexical activation and lexical selection—and examining which of these can be compensated for after left hemisphere stroke can advance the understanding of the lateralization of word retrieval in speech production. In particular, the domain-general nature of the brain regions associated with each process may be a helpful indicator of the right hemisphere's propensity for compensation. PMID:26766393

  13. Comparison between dispersive solid-phase and dispersive liquid-liquid microextraction combined with spectrophotometric determination of malachite green in water samples based on ultrasound-assisted and preconcentration under multi-variable experimental design optimization.

    Science.gov (United States)

    Alipanahpour Dil, Ebrahim; Ghaedi, Mehrorang; Asfaram, Arash; Zare, Fahimeh; Mehrabi, Fatemeh; Sadeghfar, Fardin

    2017-11-01

    The ultrasound-assisted dispersive solid-phase microextraction (USA-DSPME) and the ultrasound-assisted dispersive liquid-liquid microextraction (USA-DLLME) developed for as an ultra preconcentration and/or technique for the determination of malachite green (MG) in water samples. Central composite design based on analysis of variance and desirability function guide finding best operational conditions and represent dependency of response to variables viz. volume of extraction, eluent and disperser solvent, pH, adsorbent mass and ultrasonication time has significant influence on methods efficiency. Optimum conditions was set for USA-DSPME as: 1mg CNTs/Zn:ZnO@Ni 2 P-NCs; 4min sonication time and 130μL eluent at pH 6.0. Meanwhile optimum point for USA-DLLME conditions were fixed at pH 6.0; 4min sonication time and 130, 650μL and 10mL of extraction solvent (CHCl 3 ), disperser solvent (ethanol) and sample volume, respectively. Under the above specified best operational conditions, the enrichment factors for the USA-DSPME and USA-DLLME were 88.89 and 147.30, respectively. The methods has linear response in the range of 20.0 to 4000.0ngmL -1 with the correlation coefficients (r) between 0.9980 to 0.9995, while its reasonable detection limits viz. 1.386 to 2.348ngmL -1 and good relative standard deviations varied from 1.1% to 2.8% (n=10) candidate this method for successful monitoring of analyte from various media. The relative recoveries of the MG dye from water samples at spiking level of 500ngmL -1 were in the range between 94.50% and 98.86%. The proposed methods has been successfully applied to the analysis of the MG dye in water samples, and a satisfactory result was obtained. Copyright © 2017. Published by Elsevier B.V.

  14. Recursive ultrasound imaging

    DEFF Research Database (Denmark)

    2000-01-01

    A method and an apparatus for recursive ultrasound imaging is presented. The method uses a Synthetic Transmit Aperture, but unlike previous approaches a new frame is created at every pulse emission. In receive, parallel beam forming is implemented. The beam formed RF data is added to the previously...... created RF lines. To keep the level of the signal, the RF data obtained previously, when emitting with the same element is subtracted from the RF lines. Up to 5000 frames/sec can be achieved for a tissue depth of 15 cm with a speed of sound of c = 1540 m/s. The high frame rate makes continuous imaging...... data possible, which can significantly enhance flow imaging. A point spread function 2° wide at -6 dB and grating lobes of $m(F) -50 dB is obtained with a 64 elements phased array with a central frequency ƒ¿0? = 3 MHz using a sparse transmit aperture using only 10 elements (N¿xmt? = 10) during pulse...

  15. Behavioral evidence for left-hemisphere specialization of motor planning

    NARCIS (Netherlands)

    Janssen, L.; Meulenbroek, R.G.; Steenbergen, B.

    2011-01-01

    Recent studies suggest that the left hemisphere is dominant for the planning of motor actions. This left-hemisphere specialization hypothesis was proposed in various lines of research, including patient studies, motor imagery studies, and studies involving neurophysiological techniques. However,

  16. Determination of organophosphate flame retardants in soil and fish using ultrasound-assisted extraction, solid-phase clean-up, and liquid chromatography with tandem mass spectrometry.

    Science.gov (United States)

    Lorenzo, María; Campo, Julián; Picó, Yolanda

    2018-03-22

    A solid-liquid extraction method in combination with high-performance liquid chromatography and tandem mass spectrometry was developed and optimized for extraction and analysis of organophosphorus flame retardants in soil and fish. Methanol was chosen as the optimum extraction solvent, not only in terms of extraction efficiency, but also for its broader analyte coverage. The subsequent clean-up by solid-phase extraction is required to eliminate matrix coextractives and reduce matrix effects. Recoveries of the optimized method were 50-121% for soil and 47-123% for biota, both with high precision (RSDs solid-phase extraction cartridge clogging that increase variability and analysis time. The method was successfully applied for the determination of organophosphorus flame retardants in soil and fish from L'Albufera Natural Park (Valencia, Spain). Target compounds were detected in all soil and fish samples with values varying from 13.8 to 89.7 ng/g dry weight and from 3.3 to 53.0 ng/g wet weight, respectively. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Ultrasound extracted flavonoids from four varieties of Portuguese red grape skins determined by reverse-phase high-performance liquid chromatography with electrochemical detection.

    Science.gov (United States)

    Novak, Ivana; Janeiro, Patricia; Seruga, Marijan; Oliveira-Brett, Ana Maria

    2008-12-23

    Several flavonoids present in red grape skins from four varieties of Portuguese grapes were determined by reverse-phase high-performance liquid chromatography (RP-HPLC) with electrochemical detection (ECD). Extraction of flavonoids from red grape skins was performed by ultrasonication, and hydrochloric acid in methanol was used as extraction solvent. The developed RP-HPLC method used combined isocratic and gradient elution with amperometric detection with a glassy carbon-working electrode. Good peak resolution was obtained following direct injection of a sample of red grape extract in a pH 2.20 mobile phase. Eleven different flavonoids: cyanidin-3-O-glucoside (kuromanin), delphinidin-3-O-glucoside (myrtillin), petunidin-3-O-glucoside, peonidin-3-O-glucoside, malvidin-3-O-glucoside (oenin), (+)-catechin, rutin, fisetin, myricetin, morin and quercetin, can be separated in a single run by direct injection of sample solution. The limit of detection obtained for these compounds by ECD was 20-90 pg/L, 1000 times lower when compared with photodiode array (PDA) limit of detection of 12-55 ng/L. RP-HPLC-ECD was characterized by an excellent sensitivity and selectivity, and appropriate for the simultaneous determination of these electroactive phenolic compounds present in red grape skins.

  18. Variability of the extent of the Hadley circulation in the southern hemisphere: a regional perspective

    Science.gov (United States)

    Nguyen, H.; Hendon, H. H.; Lim, E.-P.; Boschat, G.; Maloney, E.; Timbal, B.

    2018-01-01

    In order to understand the regional impacts of variations in the extent of the Hadley circulation in the Southern Hemisphere, regional Hadley circulations are defined in three sectors centered on the main tropical heat sources over Africa, Asia-Pacific (Maritime Continent) and the Americas. These regional circulations are defined by computing a streamfunction from the divergent component of the meridional wind. A major finding from this study is that year-to-year variability in the extent of the hemispheric Hadley circulation in the Southern Hemisphere is primarily governed by variations of the extent of the Hadley circulation in the Asia-Pacific sector, especially during austral spring and summer when there is little co-variability with the African sector, and the American sector exhibits an out of phase behavior. An expanded Hadley circulation in the Southern Hemisphere (both hemispherically and in the Asia-Pacific sector) is associated with La Niña conditions and a poleward expansion of the tropical wet zone in the Asia-Pacific sector. While La Niña also promotes expansion in the American and African sectors during austral winter, these tropical conditions tend to promote contraction in the two sectors during austral summer as a result of compensating convergence over the Americas and Africa sectors: a process driven by variations in the Walker circulation and Rossby wave trains emanating from the tropical Indian Ocean.

  19. Calibration of fisheye lenses for hemispherical photography

    International Nuclear Information System (INIS)

    Diaci, J.; Kolar, U.

    2000-01-01

    Hemispherical photography represents one of the most appropriate methods of estimating averages of solar radiation over extended periods of time. This method is based upon the use of extremely wide-angle fisheye lenses, which produce large projection distortion. To correctly interpret hemispherical photography we have to know the projection characteristics of the fisheye lens in combination with a camera body. This can be achieved through lens calibration. The first part of the article explains in detail the calibration method for fisheye lenses which are used to assess the solar radiation in forest ecology research. In the second part the results of calibration for fisheye lens Sigma 8 mm, f/4 (MF, N) are presented. The lens was used on a Nikon F50 camera body

  20. Hemispheric Asymmetries in the Activation and Monitoring of Memory Errors

    Science.gov (United States)

    Giammattei, Jeannette; Arndt, Jason

    2012-01-01

    Previous research on the lateralization of memory errors suggests that the right hemisphere's tendency to produce more memory errors than the left hemisphere reflects hemispheric differences in semantic activation. However, all prior research that has examined the lateralization of memory errors has used self-paced recognition judgments. Because…

  1. The Influence of Context on Hemispheric Recruitment during Metaphor Processing

    Science.gov (United States)

    Diaz, Michele T.; Hogstrom, Larson J.

    2011-01-01

    Although the left hemisphere's prominence in language is well established, less emphasis has been placed on possible roles for the right hemisphere. Behavioral, patient, and neuroimaging research suggests that the right hemisphere may be involved in processing figurative language. Additionally, research has demonstrated that context can modify…

  2. Photometry of Southern Hemisphere red dwarf stars

    Science.gov (United States)

    Weistrop, D.

    1980-01-01

    Results are presented for a photometric investigation of a spectroscopically selected sample of red dwarf stars in the Southern Hemisphere. Absolute magnitudes and distances for the stars are estimated from broadband red colors. Three stars which may be subluminous are identified, as are several stars which may be within 25 pc. The tangential velocity and velocity dispersion of the sample are similar to values found in other studies of nearby late-type stars.

  3. Measurements of energy resolution with hemispheric scintillators

    International Nuclear Information System (INIS)

    Mendonca, A.C.S.; Binns, D.A.C.; Tauhata, L.; Poledna, R.

    1980-01-01

    The hemispheric configuration is used for plastic scintillators type NE 102 with the aiming to optimize the light collect. Scintillators at this configuration, with radii of 3,81 cm and 2,54 cm, are showing improvement about 16-17% in the energy resolution, on cilyndric scintillators with the same volume, for gamma rays of 511-1275 KeV. (E.G.) [pt

  4. An Evaluative Review of Hemispheric Learning Potential

    Science.gov (United States)

    1985-10-01

    Multiple resources in divided attention : a cross-modal te&t o£ the independence of hemispheric resources. Journal of < Experimental Psychology...found, for example, in a pianist who could play melodies without difficulty, compose new melodies at the piano, and write them down accurately...of the pair at the oppo- site ear; this procedure, referred to as dichotic presentation, has its origins in experiments on selective attention

  5. Recent climate changes in the northern hemisphere

    International Nuclear Information System (INIS)

    Trenberth, K.E.

    1990-01-01

    The consistency of analyzed changes in surface wind stress, sea level pressures and surface temperatures between 1980-86 and previous periods indicates the reality of statistically significant and substantial climate changes in the Northern Hemisphere, especially over the North Pacific, on decadal time scales. Cooling in North Pacific sea surface temperatures and warming along the west coast of North America and Alaska are ascribed mainly to the changes in thermal advection associated with a deeper and more extensive Aleutian Low

  6. Water. Unresolved emergency of the Southern hemisphere

    International Nuclear Information System (INIS)

    Lotti, C.

    2001-01-01

    Among the serious dramas in the Southern hemisphere, the most serious relates to health, and the most serious health problem is dysentery among the rural population, caused by the lack of unpolluted water. Bad management frustrates much of the aid sent to this part of the world, including projects to help the water crisis. In view of the success, it would appear that a concrete solution could be found within a decade, at a cost that can easily be sustained by the rich world, so long as funds are managed honestly. Much more ambitious and, at least for the moment, beyond all concrete possibility, is the project to provide a barrel of water per head to each person in the southern hemisphere. Providing unpolluted water and facilitating farming development through minor irrigation and family cattle-raising schemes is an idea that appears entirely Utopian. The conclusion provides a critical analysis of the major hydraulic works essential for true development, but effective only if the human environment is ready to receive them, whereas minor works are useful in any case - at village level - to resolve the thirst of the southern hemisphere [it

  7. Empirically derived climate predictability over the extratropical northern hemisphere

    Directory of Open Access Journals (Sweden)

    J. B. Elsner

    1994-01-01

    Full Text Available A novel application of a technique developed from chaos theory is used in describing seasonal to interannual climate predictability over the Northern Hemisphere (NH. The technique is based on an empirical forecast scheme - local approximation in a reconstructed phase space - for time-series data. Data are monthly 500 hPa heights on a latitude-longitude grid covering the NH from 20° N to the equator. Predictability is estimated based on the linear correlation between actual and predicted heights averaged over a forecast range of one- to twelve.month lead. The method is capable of extracting the major climate signals on this time scale including ENSO and the North Atlantic Oscillation.

  8. Southern Hemisphere extratropical circulation: Recent trends and natural variability

    Science.gov (United States)

    Thomas, Jordan L.; Waugh, Darryn W.; Gnanadesikan, Anand

    2015-07-01

    Changes in the Southern Annular Mode (SAM), Southern Hemisphere (SH) westerly jet location, and magnitude are linked with changes in ocean circulation along with ocean heat and carbon uptake. Recent trends have been observed in these fields but not much is known about the natural variability. Here we aim to quantify the natural variability of the SH extratropical circulation by using Coupled Model Intercomparison Project Phase 5 (CMIP5) preindustrial control model runs and compare with the observed trends in SAM, jet magnitude, and jet location. We show that trends in SAM are due partly to external forcing but are not outside the natural variability as described by these models. Trends in jet location and magnitude, however, lie outside the unforced natural variability but can be explained by a combination of natural variability and the ensemble mean forced trend. These results indicate that trends in these three diagnostics cannot be used interchangeably.

  9. Ultrasound contrast agents: an overview.

    Science.gov (United States)

    Cosgrove, David

    2006-12-01

    With the introduction of microbubble contrast agents, diagnostic ultrasound has entered a new era that allows the dynamic detection of tissue flow of both the macro and microvasculature. Underpinning this development is the fact that gases are compressible, and thus the microbubbles expand and contract in the alternating pressure waves of the ultrasound beam, while tissue is almost incompressible. Special software using multiple pulse sequences separates these signals from those of tissue and displays them as an overlay or on a split screen. This can be done at low acoustic pressures (MIdeveloped for myocardial perfusion. In radiology, the most important application is the liver, especially for focal disease. The approach parallels that of dynamic CT or MRI but ultrasound has the advantages of high spatial and temporal resolution. Thus, small lesions that can be indeterminate on CT can often be studied with ultrasound, and situations where the flow is very rapid (e.g., focal nodular hyperplasia where the first few seconds of arterial perfusion may be critical to making the diagnosis) are readily studied. Microbubbles linger in the extensive sinusoidal space of normal liver for several minutes whereas they wash out rapidly from metastases, which have a low vascular volume and thus appear as filling defects. The method has been shown to be as sensitive as three-phase CT. Microbubbles have clinical uses in many other applications where knowledge of the microcirculation is important (the macrocirculation can usually be assessed adequately using conventional Doppler though there are a few important situations where the signal boost given by microbubbles is useful, e.g., transcranial Doppler for evaluating vasospasm after subarachnoid haemorrhage). An important situation where demonstrating tissue devitalisation is important is in interstitial ablation of focal liver lesions: using microbubble contrast agents at the end of a procedure allows immediate evaluation of the

  10. Ultrasound-enhanced nanotherapy of pancreatic cancer

    Science.gov (United States)

    Rapoport, N.; Nam, K.-H.; Christensen, D. A.; Kennedy, A. M.; Shea, J. E.; Scaife, C. L.

    2010-03-01

    The paper reports in vivo results of ultrasonic nanotherapy of orthotopically grown pancreatic cancer. Phase-shift paclitaxel (PTX) loaded perfluoropentane (PFP) nanoemusions combined with tumor-directed ultrasound have been used with a considerable success for tumor-targeted chemotherapy of gemcitabin (GEM)-refractory pancreatic cancer (PC). The GEM-resistant pancreatic cancer proved sensitive to treatment by a micellar PTX formulation Genexol PM (GEN) andor nanodroplet PTX formulation ndGEN. Due to increased permeability of tumor blood vessels, drug-loaded nanodroplets accumulated in the tumor via passive targeting, which was confirmed by ultrasound imaging. Nanodroplets converted into microbubbles in situ under the action of tumor-directed 1-MHz therapeutic ultrasound. The strongest therapeutic effect was observed for the combination therapy by PTX-loaded nanodroplets, GEM and ultrasound (ndGEN+GEM+ultrasound). This combination therapy resulted in a spectacular tumor regression and in some cases complete tumor resolution. Moreover, formation of metastases was dramatically decreased and ascitis generation was completely suppressed. However for all animal groups, local tumor recurrence was observed after the completion of the treatment indicating that some cancer cells survived the treatment. The recurrent tumors proved more resistant to the repeated therapy than initial tumors.

  11. Contrast enhanced ultrasound in liver imaging

    International Nuclear Information System (INIS)

    Nielsen, Michael Bachmann; Bang, Nanna

    2004-01-01

    Ultrasound contrast agents were originally introduced to enhance the Doppler signals when detecting vessels with low velocity flow or when imaging conditions were sub-optimal. Contrast agents showed additional properties, it was discovered that a parenchymal enhancement phase in the liver followed the enhancement of the blood pool. Contrast agents have made ultrasound scanning more accurate in detection and characterization of focal hepatic lesions and the sensitivity is now comparable with CT and MRI scanning. Further, analysis of the transit time of contrast agent through the liver seems to give information on possible hepatic involvement, not only from focal lesions but also from diffuse benign parenchymal disease. The first ultrasound contrast agents were easily destroyed by the energy from the sound waves but newer agents have proved to last for longer time and hereby enable real-time scanning and make contrast enhancement suitable for interventional procedures such as biopsies and tissue ablation. Also, in monitoring the effect of tumour treatment contrast agents have been useful. A brief overview is given on some possible applications and on different techniques using ultrasound contrast agents in liver imaging. At present, the use of an ultrasound contrast agent that allows real-time scanning with low mechanical index is to be preferred

  12. Testing the Language of German Cerebral Palsy Patients with Right Hemispheric Language Organization after Early Left Hemispheric Damage

    Science.gov (United States)

    Schwilling, Eleonore; Krageloh-Mann, Ingeborg; Konietzko, Andreas; Winkler, Susanne; Lidzba, Karen

    2012-01-01

    Language functions are generally represented in the left cerebral hemisphere. After early (prenatally acquired or perinatally acquired) left hemispheric brain damage language functions may be salvaged by reorganization into the right hemisphere. This is different from brain lesions acquired in adulthood which normally lead to aphasia. Right…

  13. Improved heating efficiency with High-Intensity Focused Ultrasound using a new ultrasound source excitation.

    Science.gov (United States)

    Bigelow, Timothy A

    2009-01-01

    High-Intensity Focused Ultrasound (HIFU) is quickly becoming one of the best methods to thermally ablate tissue noninvasively. Unlike RF or Laser ablation, the tissue can be destroyed without inserting any probes into the body minimizing the risk of secondary complications such as infections. In this study, the heating efficiency of HIFU sources is improved by altering the excitation of the ultrasound source to take advantage of nonlinear propagation. For ultrasound, the phase velocity of the ultrasound wave depends on the amplitude of the wave resulting in the generation of higher harmonics. These higher harmonics are more efficiently converted into heat in the body due to the frequency dependence of the ultrasound absorption in tissue. In our study, the generation of the higher harmonics by nonlinear propagation is enhanced by transmitting an ultrasound wave with both the fundamental and a higher harmonic component included. Computer simulations demonstrated up to a 300% increase in temperature increase compared to transmitting at only the fundamental for the same acoustic power transmitted by the source.

  14. Lesion characteristics driving right-hemispheric language reorganization in congenital left-hemispheric brain damage.

    Science.gov (United States)

    Lidzba, Karen; de Haan, Bianca; Wilke, Marko; Krägeloh-Mann, Ingeborg; Staudt, Martin

    2017-10-01

    Pre- or perinatally acquired ("congenital") left-hemispheric brain lesions can be compensated for by reorganizing language into homotopic brain regions in the right hemisphere. Language comprehension may be hemispherically dissociated from language production. We investigated the lesion characteristics driving inter-hemispheric reorganization of language comprehension and language production in 19 patients (7-32years; eight females) with congenital left-hemispheric brain lesions (periventricular lesions [n=11] and middle cerebral artery infarctions [n=8]) by fMRI. 16/17 patients demonstrated reorganized language production, while 7/19 patients had reorganized language comprehension. Lesions to the insular cortex and the temporo-parietal junction (predominantly supramarginal gyrus) were significantly more common in patients in whom both, language production and comprehension were reorganized. These areas belong to the dorsal stream of the language network, participating in the auditory-motor integration of language. Our data suggest that the integrity of this stream might be crucial for a normal left-lateralized language development. Copyright © 2017. Published by Elsevier Inc.

  15. A hierarchically assembled mesoporous ZnO hemisphere array and hollow microspheres for photocatalytic membrane water filtration.

    Science.gov (United States)

    Pan, Jia Hong; Zhang, Xiwang; Du, Alan J; Bai, Hongwei; Ng, Jiawei; Sun, Darren

    2012-05-28

    A mesoporous ZnO hemisphere array has been prepared via a topotactic transition of Zn(4)(OH)(6)CO(3)·H(2)O (ZCHH) by chemical bath deposition. Each hemisphere is comprised of a radially oriented nanoflake shell grown on the hemispherical interior. Reaction time-dependent SEM analysis shows that the morphological formation of ZCHH involves a deposition-growth-secondary growth-redeposition procedure. Upon calcination, ZCHH readily decomposes to nanocrystalline wurtzite-phase ZnO without significant change in morphology, and the release of CO(2) and H(2)O from ZCHH creates an additional mesoporous structure in both hemispherical interior and nanoflake shell. A similar process but without using a substrate has been developed for synthesis of mesoporous ZnO hollow microspheres in powder form. Both the elaborated superstructured photocatalysts consisting of mesoporous nanoflakes have been demonstrated to exhibit excellent performances in the photocatalytic membrane filtration.

  16. Hypothalamic digoxin, hemispheric chemical dominance, and eating behavior.

    Science.gov (United States)

    Kurup, Ravi Kumar; Kurup, Parameswara Achutha

    2003-08-01

    The isoprenoid pathway produces an endogenous membrane Na+-K+ ATPase inhibitor, digoxin, which can regulate neurotransmitter and amino acid transport. Digoxin synthesis and neurotransmitter patterns were assessed in eating disorders. The patterns were compared in those with right hemispheric and left hemispheric dominance. The serum HMG CoA reductase activity, RBC membrane Na+-K+ ATPase activity, serum digoxin, magnesium, tryptophan catabolites (serotonin, quinolinic acid, strychnine, and nicotine), and tyrosine catabolites (morphine, dopamine, and noradrenaline) were measured in anorexia nervosa, bulimia nervosa, right hemispheric dominant, left hemispheric dominant, and bihemispheric dominant individuals. Digoxin synthesis was increased with upregulated tryptophan catabolism and downregulated tyrosine catabolism in those with anorexia nervosa and right hemispheric chemical dominance. Digoxin synthesis was reduced with downregulated tryptophan catabolism and upregulated tyrosine catabolism in those with bulimia nervosa and left hemispheric chemical dominance. The membrane Na+-K+ ATPase activity and serum magnesium were decreased in anorexia nervosa and right hemispheric chemical dominance while they were increased in bulimia nervosa and left hemispheric chemical dominance. Hypothalamic digoxin and hemispheric chemical dominance play a central role in the regulation of eating behavior. Anorexia nervosa represents the right hemispheric chemically dominant/hyperdigoxinemic state and bulimia nervosa the left hemispheric chemically dominant/hypodigoxinemic state.

  17. Factors Influencing Right Hemisphere Engagement During Metaphor Comprehension

    Science.gov (United States)

    Diaz, Michele T.; Eppes, Anna

    2018-01-01

    Although the left hemisphere is critical for language, clinical, behavioral, and neuroimaging research suggest that the right hemisphere also contributes to language comprehension. In particular, research has suggested that figurative language may be one type of language that preferentially engages right hemisphere regions. However, there is disagreement about whether these regions within the right hemisphere are sensitive to figurative language per se or to other factors that co-vary with figurativeness. In this article, we will review the neuroimaging literature on figurative language processing, focusing on metaphors, within the context of several theoretical perspectives that have been proposed about hemispheric function in language. Then we will examine three factors that may influence right hemisphere engagement: novelty, task difficulty, and context. We propose that factors that increase integration demands drive right hemisphere involvement in language processing, and that such recruitment is not limited to figurative language. PMID:29643825

  18. Ultrasound-assisted dispersive magnetic solid phase extraction based on amino-functionalized Fe3O4 adsorbent for recovery of clomipramine from human plasma and its determination by high performance liquid chromatography: Optimization by experimental design.

    Science.gov (United States)

    Hamidi, Fatemeh; Hadjmohammadi, Mohammad Reza; Aghaie, Ali B G

    2017-09-15

    The applicability of Amino-functionalized Fe 3 O 4 nanoparticles (NPs) as an effective adsorbent was developed for the extraction and determination of clomipramine (CLP) in plasma sample by ultrasound-assisted dispersive magnetic solid phase extraction (UADM-SPE) and high-performance liquid chromatography-ultraviolet (HPLC-UV) detection. Fabrication of the Fe 3 O 4 @SiO 2 -NH 2 magnetic nanoparticles confirmed by Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The effect of different extraction parameters (i.e. pH of the sample solution, the amount of magnetic nanoparticles (MNPs), sample volume, temperature and sonication time) on the extraction recovery of CLP were investigated by response surface methodology through central composite design (CCD). The optimum condition is obtained when the affecting parameters are set to: pH of the sample solution=9, the amount of MNPs=37mg, sample volume=23mL, 25°C temperature and sonication time=1min. Under the optimum condition, extraction recovery was 90.6% with relative standard deviation of 3.5%, and enrichment factor of 117. The linear range for determination of CLP was 0.017-0.70mgL -1 with a determination coefficient (R 2 ) of 0.999. Limit of detection (LOD) and limit of quantification (LOQ) were 0.005 and 0.0167mgL -1 , respectively. The established UADM-SPE-HPLC-UV method was rapid, simple and efficient for determination of CLP in human plasma samples. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Determination of fluorine in herbs and water samples by molecular absorption spectrometry after preconcentration on nano-TiO2 using ultrasound-assisted dispersive micro solid phase extraction.

    Science.gov (United States)

    Krawczyk-Coda, Magdalena; Stanisz, Ewa

    2017-11-01

    This work presents ultrasound-assisted dispersive micro solid phase extraction (USA DMSPE) for preconcentration of fluorine (F) in water and herb samples. TiO 2 nanoparticles (NPs) were used as an adsorbent. The determination with slurry sampling was performed via molecular absorption of calcium monofluoride (CaF) at 606.440 nm using a high-resolution continuum source electrothermal absorption spectrometry (HR-CS ET MAS). Several factors influencing the efficiency of the preconcentration technique, such as the amount of TiO 2 , pH of sample solution, ultrasonication and centrifugation time and TiO 2 slurry solution preparation before injection to HR-CS ET MAS, were investigated in detail. The conditions of detection step (wavelength, calcium amount, pyrolysis and molecule-forming temperatures) were also studied. After extraction, adsorbent with the analyte was mixed with 200 μL of H 2 O to prepare a slurry solution. The concentration limit of detection was 0.13 ng mL -1 . The achieved preconcentration factor was 7. The relative standard deviations (RSDs, %) for F in real samples were 3-15%. The accuracy of this method was evaluated by analyses of certified reference materials after spiking: INCT-MPH-2 (Mixed Polish Herbs), INCT-SBF-4 (Soya Bean Flour), ERM-CAO11b (Hard Drinking Water) and TMDA-54.5 (Lake Ontario Water). The measured F contents in reference materials were in satisfactory agreement with the added amounts, and the recoveries were found to be 97-109%. Under the developed extraction conditions, the proposed method has been successfully applied for the determination of F in real water samples (lake, sea, tap water) and herbs.

  20. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... is used to help diagnose the causes of pain, swelling and infection in the body’s internal organs ... used to help physicians evaluate symptoms such as: pain swelling infection Ultrasound is a useful way of ...

  1. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... and movement of the body's internal organs, as well as blood flowing through blood vessels. Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions. ...

  2. Stone fragmentation by ultrasound

    Indian Academy of Sciences (India)

    Unknown

    In the present work, enhancement of the kidney stone fragmentation by using ultrasound is studied. The cavi- ... ment system like radiation pressure balance, the power is given by ... Thus the bubble size has direct relationship with its life and.

  3. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the ... the transducer (the device placed on the patient's skin to send and receive the returning sound waves), ...

  4. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... ovaries , and unborn child ( fetus ) in pregnant patients eyes thyroid and parathyroid glands scrotum (testicles) brain in ... Any portions that are not wiped off will dry quickly. The ultrasound gel does not usually stain ...

  5. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... General ultrasound procedure View full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. ...

  6. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... use different transducers (with different capabilities) during a single exam. The transducer sends out high-frequency sound ... modality for the diagnosis and monitoring of pregnant women and their unborn babies. Ultrasound provides real-time ...

  7. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... collects the sounds that bounce back and a computer then uses those sound waves to create an ... types of Doppler ultrasound: Color Doppler uses a computer to convert Doppler measurements into an array of ...

  8. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... areas of the body while other areas, especially air-filled lungs, are poorly suited for ultrasound. top ... make secure contact with the body and eliminate air pockets between the transducer and the skin that ...

  9. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... image the breasts and guide biopsy of breast cancer ( see the Ultrasound-Guided Breast Biopsy page . diagnose ... are sometimes the best way to see if treatment is working or if a finding is stable ...

  10. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... a follow-up exam is done because a potential abnormality needs further evaluation with additional views or ... of soft tissues that do not show up well on x-ray images. Ultrasound is the preferred ...

  11. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... scanning or sonography , involves the use of a small transducer (probe) and ultrasound gel placed directly on ... to do the scanning. The transducer is a small hand-held device that resembles a microphone, attached ...

  12. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... Any portions that are not wiped off will dry quickly. The ultrasound gel does not usually stain ... are sometimes the best way to see if treatment is working or if a finding is stable ...

  13. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... arteries and veins in the abdomen, arms, legs, neck and/or brain (in infants and children) or ... used to help physicians evaluate symptoms such as: pain swelling infection Ultrasound is a useful way of ...

  14. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... baby in pregnant women and the brain and hips in infants. It’s also used to help guide ... and parathyroid glands scrotum (testicles) brain in infants hips in infants spine in infants Ultrasound is also ...

  15. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... organs and to examine a baby in pregnant women and the brain and hips in infants. It’s ... modality for the diagnosis and monitoring of pregnant women and their unborn babies. Ultrasound provides real-time ...

  16. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... to-use and less expensive than other imaging methods. Ultrasound imaging is extremely safe and does not ... barium exams, CT scanning , and MRI are the methods of choice in such a setting. Large patients ...

  17. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... be necessary. Your doctor will explain the exact reason why another exam is requested. Sometimes a follow- ... Ultrasound provides real-time imaging, making it a good tool for guiding minimally invasive procedures such as ...

  18. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... the transducer for analysis. Ultrasound has difficulty penetrating bone and, therefore, can only see the outer surface ... children or adults). For visualizing internal structure of bones or certain joints, other imaging modalities such as ...

  19. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the probe through ... a single exam. The transducer sends out high-frequency sound waves (that the human ear cannot hear) ...

  20. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... in infections With knowledge about the speed and volume of blood flow gained from a Doppler ultrasound ... Some exams may use different transducers (with different capabilities) during a single exam. The transducer sends out ...

  1. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... biopsies , in which needles are used to sample cells from an abnormal area for laboratory testing. image ... ultrasound, measures the direction and speed of blood cells as they move through vessels. The movement of ...

  2. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... sends out high-frequency sound waves (that the human ear cannot hear) into the body and then ... ultrasound , there are no known harmful effects on humans. top of page What are the limitations of ...

  3. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... heartbeat. top of page What are some common uses of the procedure? Ultrasound examinations can help to ... is done because a potential abnormality needs further evaluation with additional views or a special imaging technique. ...

  4. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... patient. Because ultrasound images are captured in real-time, they can show the structure and movement of ... terms of the distance traveled per unit of time, rather than as a color picture. It can ...

  5. Abdominal ultrasound (image)

    Science.gov (United States)

    Abdominal ultrasound is a scanning technique used to image the interior of the abdomen. Like the X- ... use high frequency sound waves to produce an image and do not expose the individual to radiation. ...

  6. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... spleen pancreas kidneys bladder uterus , ovaries , and unborn child ( fetus ) in pregnant patients eyes thyroid and parathyroid glands scrotum (testicles) brain in infants hips in infants spine in infants Ultrasound is also used to: guide ...

  7. General Ultrasound Imaging

    Science.gov (United States)

    ... spleen pancreas kidneys bladder uterus , ovaries , and unborn child ( fetus ) in pregnant patients eyes thyroid and parathyroid glands scrotum (testicles) brain in infants hips in infants spine in infants Ultrasound is also used to: guide ...

  8. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... ultrasound images are captured in real-time, they can show the structure and movement of the body's ... time, rather than as a color picture. It can also convert blood flow information into a distinctive ...

  9. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... and be made aware of food and drink restrictions that may be needed prior to sedation. Once ... modality for the diagnosis and monitoring of pregnant women and their unborn babies. Ultrasound provides real-time ...

  10. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... is General Ultrasound Imaging? What are some common uses of the procedure? How should I prepare? What does the equipment look like? How does the procedure work? How is the procedure performed? What will I ...

  11. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... ultrasound procedure View full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media Angioplasty and Vascular Stenting ...

  12. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... as needle biopsies and fluid aspiration. Risks For standard diagnostic ultrasound , there are no known harmful effects ... possible charges you will incur. Web page review process: This Web page is reviewed regularly by a ...

  13. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... Videos related to General Ultrasound Sponsored by Please note RadiologyInfo.org is not a medical facility. Please ... is further reviewed by committees from the American College of Radiology (ACR) and the Radiological Society of ...

  14. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... needles are used to sample cells from an abnormal area for laboratory testing. image the breasts and ... of organs, tissues, and vessels or to detect abnormal masses, such as tumors. In an ultrasound examination, ...

  15. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... object is solid or filled with fluid). In medicine, ultrasound is used to detect changes in appearance, ... have special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media Angioplasty and ...

  16. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... Send us your feedback Did you find the information you were looking for? Yes No Please type your comment or suggestion ... General ultrasound procedure View full size with caption Pediatric ...

  17. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... heartbeat. top of page What are some common uses of the procedure? Ultrasound examinations can help to ... community, you can search the ACR-accredited facilities database . This website does not provide cost information. The ...

  18. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... kidneys. There are three types of Doppler ultrasound: Color Doppler uses a computer to convert Doppler measurements into an array of colors to show the speed and direction of blood ...

  19. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... of the reflected sound waves (called the Doppler effect). A computer collects and processes the sounds and ... standard diagnostic ultrasound , there are no known harmful effects on humans. top of page What are the ...

  20. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... biopsies , in which needles are used to sample cells from an abnormal area for laboratory testing. image the breasts and guide biopsy of breast cancer ( see the Ultrasound-Guided Breast Biopsy page . diagnose ...

  1. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... fitting clothing for your ultrasound exam. You may need to remove all clothing and jewelry in the ... using the same transducer. Rarely, young children may need to be sedated in order to hold still ...

  2. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... various body organs such as the liver or kidneys. There are three types of Doppler ultrasound: Color ... and its major branches liver gallbladder spleen pancreas kidneys bladder uterus , ovaries , and unborn child ( fetus ) in ...

  3. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... echoes from the tissues in the body. The principles are similar to sonar used by boats and ... work? Ultrasound imaging is based on the same principles involved in the sonar used by bats, ships ...

  4. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... organs and to examine a baby in pregnant women and the brain and hips in infants. It’s ... Transvaginal ultrasound. The transducer is inserted into a woman's vagina to view the uterus and ovaries. top ...

  5. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... most ultrasound exams, you will be positioned lying face-up on an examination table that can be ... in a known abnormality can be monitored over time. Follow-up examinations are sometimes the best way ...

  6. [Basics of emergency ultrasound].

    Science.gov (United States)

    Schellhaas, S; Breitkreutz, R

    2012-09-05

    Focused ultrasound is a key methodology of critical care medicine. By referencing few ultrasound differential diagnosis, it is possible to identifying in real-time the reason of the critical state of a patient. Therefore typical focused ultrasound protocols were developed. The well known Focused Assessment with Sonography for trauma (FAST) was incorporated into the Advanced Trauma Life Support (ATLS) for shock room. Focused echocardiographic evaluation in life support (FEEL) has been designed to be conformed with the universal Advanced Life Support (ALS) algorithm and to identify treatable conditions such as acute right ventricular pressure overload in pulmonary embolism, hypovolemia, or pericardial effusion/tamponade. Using lung ultrasound one can differentiate pulmonary edema, pleural effusion or pneumothorax.

  7. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... consist of a console containing a computer and electronics, a video display screen and a transducer that ... the preferred imaging modality for the diagnosis and monitoring of pregnant women and their unborn babies. Ultrasound ...

  8. Effect of ultrasound on electrochemical chloride extraction from mortar

    Science.gov (United States)

    Chen, Yiqun; Yao, Wu; Zuo, Junqing

    2018-03-01

    In this paper, the effect of auxiliary ultrasound on electrochemical chloride extraction (ECE) was studied. The chloride removal efficiency was investigated by examining the chloride content with ultrasound-assisted ECE and changing the introducing time of ultrasound. The experimental results showed that removal of chloride ions was noted to be more effective in ECE treatment assisted with ultrasound treatment (UT). In addition, the lower w/c ratio led to more distinct effect of ultrasonic cavitation on chloride removal. Electrochemical behaviors measured with different treatment revealed that UT treatment was effective on moderating the corrosion condition. Microstructural analyses revealed a significant alteration in composition and morphology of cementitious phases with UT treatment. Pull-out tests indicated that ultrasound had a certain negative impact on the bond strength. Although the effect of introducing ultrasound in the first 2 weeks or the last 2 weeks on the extraction efficiency was not obvious, intermittent ultrasound could not only ensure the chloride extraction efficiency, but also reduce the adverse effect of ultrasound on the bond strength.

  9. Application of power ultrasound in radiochemistry

    International Nuclear Information System (INIS)

    Moisy, Ph.; Venault, L.; Blanc, P.; Madic, C.; Nikitenko, S.

    1998-01-01

    The chemical effects of ultrasound are related to cavitation process: nucleation, bubble growth and cavitation collapse. Sono-chemical reactions occur due to the rapid heating of the contents of cavitation bubbles. The shock-waves generated by cavitation collapse cause intense emulsification of the immiscible liquids. The CEA/Marcoule research group investigated the effect of power ultrasound on the homogeneous and heterogeneous (liquid-liquid) actinide reactions, in aqueous nitric acid media. It was found that U(IV), Np(V) and Pu(III) can be rapidly oxidized in HNO 3 solutions by HNO 2 , generated by the effect of power ultrasound on HNO 3 solutions. HNO 2 , formed during HNO 3 sono-lysis, decomposes hydrazinium nitrate within the cavitation bubbles. This makes it possible to the control actinide oxidation states without adding any side chemical reagents (NaNO 2 , for example). The quantitative data on the effect in the ultrasonic field in nitric acid medium are discussed, and sono-chemical mechanisms are proposed for nitrous acid formation and hydrazinium nitrate decomposition. In the presence of anti-nitrous reagents, such as hydrazinium nitrate and sulfamic acid, U(IV) was found to be oxidized and Pu(IV) reduced by H 2 O 2 formed as the result of aqueous nitric acid sono-lysis. The kinetics of H 2 O 2 formation is faster than in water, for the same sono-chemical conditions. Np(V) is rapidly oxidized, by aqueous phase HNO 2 , under the effect of ultrasound on the two-phase system TBP-dodecane/HNO 3 . Intense emulsification of the liquid/liquid system accelerates the mass transfer, of Np(VI) formed, into the organic phase. The quantitative effect of power ultrasound in aqueous nitric acid, with or without anti-nitrous reagents, can be used to predict the behavior of actinides in the ultrasonic field in nitric acid medium. (author)

  10. [Ultrasound findings in rhabdomyolysis].

    Science.gov (United States)

    Carrillo-Esper, Raúl; Galván-Talamantes, Yazmin; Meza-Ayala, Cynthia Margarita; Cruz-Santana, Julio Alberto; Bonilla-Reséndiz, Luis Ignacio

    Rhabdomyolysis is defined as skeletal muscle necrosis. Ultrasound assessment has recently become a useful tool for the diagnosis and monitoring of muscle diseases, including rhabdomyolysis. A case is presented on the ultrasound findings in a patient with rhabdomyolysis. To highlight the importance of ultrasound as an essential part in the diagnosis in rhabdomyolysis, to describe the ultrasound findings, and review the literature. A 30 year-old with post-traumatic rhabdomyolysis of both thighs. Ultrasound was performed using a Philips Sparq model with a high-frequency linear transducer (5-10MHz), in low-dimensional scanning mode (2D), in longitudinal and transverse sections at the level of both thighs. The images obtained showed disorganisation of the orientation of the muscle fibres, ground glass image, thickening of the muscular fascia, and the presence of anechoic areas. Ultrasound is a useful tool in the evaluation of rhabdomyolysis. Copyright © 2015 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.

  11. Phenological Changes in the Southern Hemisphere

    Science.gov (United States)

    Chambers, Lynda E.; Altwegg, Res; Barbraud, Christophe; Barnard, Phoebe; Beaumont, Linda J.; Crawford, Robert J. M.; Durant, Joel M.; Hughes, Lesley; Keatley, Marie R.; Low, Matt; Morellato, Patricia C.; Poloczanska, Elvira S.; Ruoppolo, Valeria; Vanstreels, Ralph E. T.; Woehler, Eric J.; Wolfaardt, Anton C.

    2013-01-01

    Current evidence of phenological responses to recent climate change is substantially biased towards northern hemisphere temperate regions. Given regional differences in climate change, shifts in phenology will not be uniform across the globe, and conclusions drawn from temperate systems in the northern hemisphere might not be applicable to other regions on the planet. We conduct the largest meta-analysis to date of phenological drivers and trends among southern hemisphere species, assessing 1208 long-term datasets from 89 studies on 347 species. Data were mostly from Australasia (Australia and New Zealand), South America and the Antarctic/subantarctic, and focused primarily on plants and birds. This meta-analysis shows an advance in the timing of spring events (with a strong Australian data bias), although substantial differences in trends were apparent among taxonomic groups and regions. When only statistically significant trends were considered, 82% of terrestrial datasets and 42% of marine datasets demonstrated an advance in phenology. Temperature was most frequently identified as the primary driver of phenological changes; however, in many studies it was the only climate variable considered. When precipitation was examined, it often played a key role but, in contrast with temperature, the direction of phenological shifts in response to precipitation variation was difficult to predict a priori. We discuss how phenological information can inform the adaptive capacity of species, their resilience, and constraints on autonomous adaptation. We also highlight serious weaknesses in past and current data collection and analyses at large regional scales (with very few studies in the tropics or from Africa) and dramatic taxonomic biases. If accurate predictions regarding the general effects of climate change on the biology of organisms are to be made, data collection policies focussing on targeting data-deficient regions and taxa need to be financially and logistically

  12. Phenological changes in the southern hemisphere.

    Directory of Open Access Journals (Sweden)

    Lynda E Chambers

    Full Text Available Current evidence of phenological responses to recent climate change is substantially biased towards northern hemisphere temperate regions. Given regional differences in climate change, shifts in phenology will not be uniform across the globe, and conclusions drawn from temperate systems in the northern hemisphere might not be applicable to other regions on the planet. We conduct the largest meta-analysis to date of phenological drivers and trends among southern hemisphere species, assessing 1208 long-term datasets from 89 studies on 347 species. Data were mostly from Australasia (Australia and New Zealand, South America and the Antarctic/subantarctic, and focused primarily on plants and birds. This meta-analysis shows an advance in the timing of spring events (with a strong Australian data bias, although substantial differences in trends were apparent among taxonomic groups and regions. When only statistically significant trends were considered, 82% of terrestrial datasets and 42% of marine datasets demonstrated an advance in phenology. Temperature was most frequently identified as the primary driver of phenological changes; however, in many studies it was the only climate variable considered. When precipitation was examined, it often played a key role but, in contrast with temperature, the direction of phenological shifts in response to precipitation variation was difficult to predict a priori. We discuss how phenological information can inform the adaptive capacity of species, their resilience, and constraints on autonomous adaptation. We also highlight serious weaknesses in past and current data collection and analyses at large regional scales (with very few studies in the tropics or from Africa and dramatic taxonomic biases. If accurate predictions regarding the general effects of climate change on the biology of organisms are to be made, data collection policies focussing on targeting data-deficient regions and taxa need to be financially

  13. Shape preferred orientation of iron grains compatible with Earth's uppermost inner core hemisphericity

    Science.gov (United States)

    Calvet, Marie; Margerin, Ludovic

    2018-01-01

    Constraining the possible patterns of iron fabrics in the Earth's Uppermost Inner Core (UIC) is key to unravel the mechanisms controlling its growth and dynamics. In the framework of crystalline micro-structures composed of ellipsoidal, aligned grains, we discuss possible textural models of UIC compatible with observations of P-wave attenuation and velocity dispersion. Using recent results from multiple scattering theory in textured heterogeneous materials, we compute the P-wave phase velocity and scattering attenuation as a function of grain volume, shape, and orientation wrt to the propagation direction of seismic P-waves. Assuming no variations of the grain volume between the Eastern and Western hemisphere, we show that two families of texture are compatible with the degree-one structure of the inner core as revealed by the positive correlation between seismic velocity and attenuation. (1) Strong flattening of grains parallel to the Inner Core Boundary in the Western hemisphere and weak anisometry in the Eastern hemisphere. (2) Strong radial elongation of grains in the Western hemisphere and again weak anisometry in the Eastern hemisphere. Both textures can quantitatively explain the seismic data in a limited range of grain volumes. Furthermore, the velocity and attenuation anisotropy locally observed under Africa demands that the grains be locally elongated in the direction of Earth's meridians. Our study demonstrates that the hemispherical seismic structure of UIC can be entirely explained by changes in the shape and orientation of grains, thereby offering an alternative to changes in grain volumes. In the future, our theoretical toolbox could be used to systematically test the compatibility of textures predicted by geodynamical models with seismic observations.

  14. Hemispheric dominance and cell phone use.

    Science.gov (United States)

    Seidman, Michael D; Siegel, Bianca; Shah, Priyanka; Bowyer, Susan M

    2013-05-01

    A thorough understanding of why we hold a cell phone to a particular ear may be of importance when studying the impact of cell phone safety. To determine if there is an obvious association between sidedness of cell phone use and auditory hemispheric dominance (AHD) or language hemispheric dominance (LHD). It is known that 70% to 95% of the population are right-handed, and of these, 96% have left-brain LHD. We have observed that most people use their cell phones in their right ear. An Internet survey was e-mailed to individuals through surveymonkey.com. The survey used a modified Edinburgh Handedness Inventory protocol. Sample questions surveyed which hand was used to write with, whether the right or left ear was used for phone conversations, as well as whether a brain tumor was present. General community. An Internet survey was randomly e-mailed to 5000 individuals selected from an otology online group, patients undergoing Wada testing and functional magnetic resonance imaging, as well as persons on the university listserv, of which 717 surveys were completed. Determination of hemispheric dominance based on preferred ear for cell phone use. A total of 717 surveys were returned. Ninety percent of the respondents were right handed, and 9% were left handed. Sixty-eight percent of the right-handed people used the cell phone in their right ear, 25% in the left ear, and 7% had no preference. Seventy-two of the left-handed respondents used their left ear, 23% used their right ear, and 5% had no preference. Cell phone use averaged 540 minutes per month over the past 9 years. An association exists between hand dominance laterality of cell phone use (73%) and our ability to predict hemispheric dominance. Most right-handed people have left-brain LHD and use their cell phone in their right ear. Similarly, most left-handed people use their cell phone in their left ear. Our study suggests that AHD may differ from LHD owing to the difference in handedness and cell phone ear use

  15. HEMISPHERIC ASYMMETRIES IN THE POLAR SOLAR WIND OBSERVED BY ULYSSES NEAR THE MINIMA OF SOLAR CYCLES 22 AND 23

    International Nuclear Information System (INIS)

    Ebert, R. W.; Dayeh, M. A.; Desai, M. I.; McComas, D. J.; Pogorelov, N. V.

    2013-01-01

    We examined solar wind plasma and interplanetary magnetic field (IMF) observations from Ulysses' first and third orbits to study hemispheric differences in the properties of the solar wind and IMF originating from the Sun's large polar coronal holes (PCHs) during the declining and minimum phase of solar cycles 22 and 23. We identified hemispheric asymmetries in several parameters, most notably ∼15%-30% south-to-north differences in averages for the solar wind density, mass flux, dynamic pressure, and energy flux and the radial and total IMF magnitudes. These differences were driven by relatively larger, more variable solar wind density and radial IMF between ∼36°S-60°S during the declining phase of solar cycles 22 and 23. These observations indicate either a hemispheric asymmetry in the PCH output during the declining and minimum phase of solar cycles 22 and 23 with the southern hemisphere being more active than its northern counterpart, or a solar cycle effect where the PCH output in both hemispheres is enhanced during periods of higher solar activity. We also report a strong linear correlation between these solar wind and IMF parameters, including the periods of enhanced PCH output, that highlight the connection between the solar wind mass and energy output and the Sun's magnetic field. That these enhancements were not matched by similar sized variations in solar wind speed points to the mass and energy responsible for these increases being added to the solar wind while its flow was subsonic.

  16. Atypical hemispheric dominance for attention: functional MRI topography.

    Science.gov (United States)

    Flöel, Agnes; Jansen, Andreas; Deppe, Michael; Kanowski, Martin; Konrad, Carsten; Sommer, Jens; Knecht, Stefan

    2005-09-01

    The right hemisphere is predominantly involved in tasks associated with spatial attention. However, left hemispheric dominance for spatial attention can be found in healthy individuals, and both spatial attention and language can be lateralized to the same hemisphere. Little is known about the underlying regional distribution of neural activation in these 'atypical' individuals. Previously a large number of healthy subjects were screened for hemispheric dominance of visuospatial attention and language, using functional Doppler ultrasonography. From this group, subjects were chosen who were 'atypical' for hemispheric dominance of visuospatial attention and language, and their pattern of brain activation was studied with functional magnetic resonance imaging during a task probing spatial attention. Right-handed subjects with the 'typical' pattern of brain organization served as control subjects. It was found that subjects with an inverted lateralization of language and spatial attention (language right, attention left) recruited left-hemispheric areas in the attention task, homotopic to those recruited by control subjects in the right hemisphere. Subjects with lateralization of both language and attention to the right hemisphere activated an attentional network in the right hemisphere that was comparable to control subjects. The present findings suggest that not the hemispheric side, but the intrahemispheric pattern of activation is the distinct feature for the neural processes underlying language and attention.

  17. Hemispheric specialization in dogs for processing different acoustic stimuli.

    Directory of Open Access Journals (Sweden)

    Marcello Siniscalchi

    Full Text Available Considerable experimental evidence shows that functional cerebral asymmetries are widespread in animals. Activity of the right cerebral hemisphere has been associated with responses to novel stimuli and the expression of intense emotions, such as aggression, escape behaviour and fear. The left hemisphere uses learned patterns and responds to familiar stimuli. Although such lateralization has been studied mainly for visual responses, there is evidence in primates that auditory perception is lateralized and that vocal communication depends on differential processing by the hemispheres. The aim of the present work was to investigate whether dogs use different hemispheres to process different acoustic stimuli by presenting them with playbacks of a thunderstorm and their species-typical vocalizations. The results revealed that dogs usually process their species-typical vocalizations using the left hemisphere and the thunderstorm sounds using the right hemisphere. Nevertheless, conspecific vocalizations are not always processed by the left hemisphere, since the right hemisphere is used for processing vocalizations when they elicit intense emotion, including fear. These findings suggest that the specialisation of the left hemisphere for intraspecific communication is more ancient that previously thought, and so is specialisation of the right hemisphere for intense emotions.

  18. Plutonium in Southern Hemisphere Ocean Waters

    Energy Technology Data Exchange (ETDEWEB)

    Hirose, K. [Sophia University, Tokyo (Japan); Aoyama, M. [Meteorological Research Institute, Tsukuba (Japan); Gastaud, J.; Levy, I. [Marine Environment Laboratories, International Atomic Energy Agency (Monaco); Fukasawa, M. [Japan Agency for Marine-Earth Science and Technology Yokosuka (Japan); Kim, C. -S. [Environment Laboratories, International Atomic Energy Agency, Seibersdorf (Austria); Povinec, P. P. [Comenius University, Bratislava (Slovakia); Roos, P. [Riso National Laboratory, Roskilde (Denmark); Sanchez-Cabeza, J. A. [Universitat Autonoma de Barcelona, Bellaterra (Spain); Yim, S. A. [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2013-07-15

    Plutonium in seawater collected by the BEAGLE2003 cruise was determined using ICP-SF-MS and alpha spectrometry after Fe co-precipitation and radiochemical purification. Levels and distributions of dissolved plutonium activity concentrations in Southern Hemisphere ocean waters are summarized here, including historical data. Pu-239 concentrations in surface water of the central South Pacific (32.5{sup o}S) in 2003 were around 1 mBq/m{sup 3}. The {sup 239}Pu concentrations in the Indian Ocean surface waters (20{sup o}S) were similar to that in the South Pacific, whereas the {sup 239}Pu concentrations in the South Atlantic surface waters (30{sup o}S) were markedly lower than those in the South Pacific and Indian Oceans. The {sup 239}Pu vertical profile pattern was similar to that in the North Pacific subtropical gyre, although {sup 239}Pu concentrations in the deep South Pacific were significantly lower than those in the North Pacific. One of the dominant factors controlling plutonium distributions in the Southern Hemisphere oceans is biogeochemical processes including particle scavenging. (author)

  19. Hemispheric and facial asymmetry: faces of academe.

    Science.gov (United States)

    Smith, W M

    1998-11-01

    Facial asymmetry (facedness) of selected academic faculty members was studied in relation to brain asymmetry and cognitive specialization. Comparisons of facedness were made among humanities faculty (H), faculty members of mathematics and physics (M-P), psychologists (P), and a group of randomly selected individuals (R). Facedness was defined in terms of the relative sizes (in square centimeters) of the two hemifaces. It was predicted that the four groups would show differences in facedness, namely, H, right face bias; M-P, left face bias; P, no bias; and R, no bias. The predictions were confirmed, and the results interpreted in terms of known differences in hemispheric specialization of cognitive functions as they relate to the dominant cognitive activity of each of the different groups. In view of the contralateral control of the two hemifaces (below the eyes) by the two hemispheres of the brain, the two sides of the face undergo differential muscular development, thus creating facial asymmetry. Other factors, such as gender, also may affect facial asymmetry. Suggestions for further research on facedness are discussed.

  20. Atypical Hemispheric Specialization for Faces in Infants At-Risk for Autism Spectrum Disorder

    Science.gov (United States)

    Keehn, Brandon; Vogel-Farley, Vanessa; Tager-Flusberg, Helen; Nelson, Charles A.

    2014-01-01

    Behavioral and neuroimaging findings from typically developing infants and children have demonstrated that the right hemisphere becomes specialized for processing faces. Face processing impairments and atypical hemispheric specialization have previously been reported in individuals with autism spectrum disorder (ASD). The goal of this study was to examine the emergence of the right-lateralized face processing network in infants at high-risk for autism (HRA; defined as having an older sibling with ASD) and low-risk comparison (LRC) infants, defined as having no family history of ASD. To investigate the earliest appearance of these features, we examined lateralization of event-related gamma-band coherence (a measure of intra-hemispheric connectivity) to faces during the first year of life. Forty-nine HRA and 46 LRC infants contributed a total of 127 data sets at 6- and/or 12-months. EEG was recorded while infants viewed pictures of either their mother or a stranger. Event-related gamma-band (30-50Hz) phase coherence between anterior-posterior regions for left and right hemispheres was computed. HRA infants showed an aberrant pattern of leftward lateralization of intra-hemispheric coherence by the end of the first year of life, suggesting that the network specialized for face processing may develop atypically in these infants. Further, infants with the greatest leftward asymmetry at 12-months were those that later met diagnostic criteria for ASD, providing support to the growing body of evidence that atypical hemispheric specialization may be an early neurobiological marker for ASD. Among the many experimental findings that tend to distinguish those with and without autism spectrum disorder (ASD) are face processing deficits, reduced hemispheric specialization, and atypical neurostructural and functional connectivity. To investigate the earliest manifestations of these features, we examined lateralization of event-related gamma-band coherence to faces during the first