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high frequency ultrasound

Hamza Ferkous, Slimane Merouani, Oualid Hamdaoui, Christian Pétrier
This work explores the effect of persulfate (PS) on the sonochemical degradation of organic pollutants taking naphthol blue black (NBB), an anionic diazo dye, as a substrate model. The sonolytic experiments were conducted in the absence and presence of PS under various experimental conditions including acoustic power (10-80W), frequency (20 and 585kHz) and saturating gas (argon, air and nitrogen). Experimental results showed that PS decomposition into sulfate radical (SO4(-)) takes place by sonolysis and increasing PS concentration up to 1g/L would result in an increase in the NBB degradation rate...
January 2017: Ultrasonics Sonochemistry
Markus Kauer, Valentina Belova-Magri, Carlos Cairós, Hans-Jürgen Schreier, Robert Mettin
Despite the increasing use of high frequency ultrasound in heterogeneous reactions, knowledge about the spatial distribution of cavitation bubbles at the irradiated solid surface is still lacking. This gap hinders controllable surface sonoreactions. Here we present an optimization study of the cavitation bubble distribution at a solid sample using sonoluminescence and sonochemiluminescence imaging. The experiments were performed at three ultrasound frequencies, namely 580, 860 and 1142kHz. We found that position and orientation of the sample to the transducer, as well as its material properties influence the distribution of active cavitation bubbles at the sample surface in the reactor...
January 2017: Ultrasonics Sonochemistry
Shan Chong, Guangming Zhang, Zhongheng Wei, Nan Zhang, Ting Huang, Yucan Liu
This paper studies the sonocatalytic degradation of diclofenac in water using FeCeOx-catalyzed ultrasound. The effects of pre-adsorption and gas addition were investigated. Nitrogen adsorption/desorption, SEM, XRD, Raman and XPS analyses of FeCeOx before and after sonication were characterized. The proposed mechanism was based on the microstructure changes of FeCeOx and reactive-species-scavenging performances. The results show that FeCeOx has excellent performance in catalyzing an ultrasonic system in water, and 80% of diclofenac was removed in 30min ([Diclofenac]=20mg/L, FeCeOx amount=0...
January 2017: Ultrasonics Sonochemistry
K Shikha Ojha, Timothy J Mason, Colm P O'Donnell, Joseph P Kerry, Brijesh K Tiwari
Fermentation processes involve the participation of enzymes and organic catalysts, generated by range of microorganisms to produce chemical transformations. Ultrasound can be used in such processes to either monitor the progress of fermentation or to influence its progress. High frequency ultrasound (>2MHz) has been extensively reported as a tool for the measurement of the changes in chemical composition during fermentation providing real time information on reaction progress. Low frequency ultrasound (20-50kHz) can influence the course of fermentation by improving mass transfer and cell permeability leading to improved process efficiency and production rates...
January 2017: Ultrasonics Sonochemistry
Cheng Liu, Zhen Cao, Jie Wang, Zhehao Sun, Siyuan He, Wei Chen
Ultrasonication pretreatment of raw water with high content of algal cells might cause an increase in dissolved organic nitrogen (DON) and proteins, which must be removed effectively before coagulation. In this study, the efficiency of sonication treatment in removing typical proteins derived from algal cells was investigated by applying ultrasonic waves at 20, 40, 60, 80, and 100kHz, and the influencing factors and removal mechanism were discussed. The results showed that low-frequency sonication could degrade phycocyanin to some extent, achieving about 95% removal rate after 150min of sonication...
January 2017: Ultrasonics Sonochemistry
Xiaojian Ma, Biao Huang, Guoyu Wang, Mindi Zhang
The objective of this paper is to investigate the transient conical bubble structure (CBS) and acoustic flow structure in ultrasonic field. In the experiment, the high-speed video and particle image velocimetry (PIV) techniques are used to measure the acoustic cavitation patterns, as well as the flow velocity and vorticity fields. Results are presented for a high power ultrasound with a frequency of 18kHz, and the range of the input power is from 50W to 250W. The results of the experiment show the input power significantly affects the structures of CBS, with the increase of input power, the cavity region of CBS and the velocity of bubbles increase evidently...
January 2017: Ultrasonics Sonochemistry
Cheng Liu, Yakun Sun, Dongying Wang, Zhehao Sun, Ming Chen, Zhi Zhou, Wei Chen
Biological activated carbon (BAC) filter has been widely used as an effective water treatment but regenerations of BAC are costly. Ultrasound has been successfully applied for regeneration of activated carbon but has been less frequently applied to the regenerate the BAC. In this study, bench-scale and pilot-scale experiments were conducted to evaluate the regeneration performance and mechanism of BAC with low-frequency ultrasound. Adsorption indices, microbiological parameters, pore structure and removal efficiencies were further investigated...
January 2017: Ultrasonics Sonochemistry
Jose Carlos P Ferreira, Francesca R Grati, Komal Bajaj, Francesca Malvestiti, Maria Beatrice Grimi, Anna Trotta, Rosaria Liuti, Silvia Milani, Lara Branca, Jacob Hartman, Federico Maggi, Giuseppe Simoni, Susan J Gross
OBJECTIVES: No previous studies have reported the frequencies of individual chromosomal anomalies in normal-appearing fetuses stratified by maternal age (MA) and gestational age (GA). We therefore sought to (1) characterize the frequency of all fetal karyotype anomalies in sonographically normal appearing fetuses without pretest risk factors, and (2) assess MA and GA impact on the proportion of anomalies targeted by screening and consequent impact on residual risk following a negative result...
October 21, 2016: Prenatal Diagnosis
Severiano R Silva, Rita Payan-Carreira, Miguel Quaresma, Cristina M Guedes, Ana Sofia Santos
BACKGROUND: In equids, health and welfare depend on body composition. A growing number of equids are now used as leisure and companion animals, and often found overfeed. The need for a close monitoring of body fatness led to the search for tools allowing a rapid and non-invasive estimation of fatness. This study intends to assess real-time ultrasonography (RTU) usefulness in establishing a relationship between ultrasound measures of subcutaneous fat-plus-skin thickness (SF-Skin) and body condition score (BCS) in horses and donkeys...
October 20, 2016: Acta Veterinaria Scandinavica
Jennie Engstrand, Grzegorz Toporek, Piotr Harbut, Eduard Jonas, Henrik Nilsson, Jacob Freedman
OBJECTIVE: The purpose of the present study is to evaluate the accuracy and safety of antenna placement performed with the use of a CT-guided stereotactic navigation system for percutaneous ablation of liver tumors and to assess the safety of high-frequency jet ventilation for target motion control. MATERIALS AND METHODS: Twenty consecutive patients with malignant liver lesions for which surgical resection was contraindicated or that were not readily visible on ultrasound or not accessible by ultrasound guidance were included in the study...
October 20, 2016: AJR. American Journal of Roentgenology
Toshiyuki Takahashi, Yasuyuki Sato, Takeshi Yamazaki, Asako Hayashi, Takayuki Okamoto
BACKGROUND: Most patients with congenital nephrotic syndrome (CNS) exhibit a failure to thrive. A previous study reported that five of 41 (12 %) infants with CNS had hypertrophic pyloric stenosis (HPS) requiring surgery. The reason for this is undetermined, and there are few reports regarding the relationship between these conditions or their clinical course. CASE DIAGNOSIS/TREATMENT: We present the case of a 4-month-old girl with CNS. She did not show typical manifestations of HPS, but thickened mucosal and submucosal layers and hypertrophy of the pyloric muscle were detected by repeated ultrasound examinations prior to the diagnosis of HPS...
October 18, 2016: Pediatric Nephrology: Journal of the International Pediatric Nephrology Association
Di Liu, Yizhi Liang, Long Jin, Huojiao Sun, Linghao Cheng, Bai-Ou Guan
We have developed highly sensitive photonic ultrasound hydrophones based on polymer-packaged dual-polarization-mode fiber lasers. The incident ultrasound wave is scattered by the polymer cylinder due to the difference in elastic property. The scattered wave can drive harmonic vibration of the cylinder and result in optical response in terms of beat-frequency variation of the laser output. Experimental results exhibit a broadband ultrasound response at frequencies below 1 MHz. The individual vibration modes are excited by the ultrasound waves with different efficiencies, yielding a frequency-dependent response...
October 1, 2016: Optics Letters
Stephanie Preuss, Claudius Kuechle, Stefan Wagenpfeil, Christoph Schmaderer, Lutz Renders, Uwe Heemann, Konrad Stock
The aim of this retrospective single-center study was to examine ultrasound-detected complications after diagnostic parenchymal renal biopsies. After 471 ultrasound-guided kidney biopsies (225 native kidneys and 246 renal allografts), ultrasound revealed hematomas (21.9%), arterio-venous fistulas (8.9%), active bleeding (1.1%) and hematuria (0.4%). Only 0.8% of all patients required invasive intervention such as coiling (n = 3) and surgical procedures (n = 1). Three episodes of bleeding (0.6%) were solved with manual compression...
October 13, 2016: Ultrasound in Medicine & Biology
Georgios Tsivgoulis, Andrei V Alexandrov
PURPOSE OF REVIEW: Low cost, avoidance of irradiation, and high temporal resolution are inherent advantages of ultrasound imaging that translate into multiple clinical uses in many domains of neurology. This article presents clinical uses of ultrasound examination in cerebrovascular, neurodegenerative, and peripheral nervous system diseases. RECENT FINDINGS: Modern treatment and prevention of ischemic stroke rely on prompt diagnosis. Ultrasonography has found a place as a noninvasive screening test and bedside technique that provides estimates of the degree of stenosis as well as hemodynamic and structural information about intracranial and extracranial vessels in real time...
October 2016: Continuum: Lifelong Learning in Neurology
Zhao-Yang Lu, Rui-Lin Li, Hong-Sheng Zhou, Jing-Juan Huang, Zhi-Xiao Su, Jia Qi, Lan Zhang, Yue Li, Yi-Qin Shi, Chang-Ning Hao, Jun-Li Duan
Therapeutic ultrasound (TUS) has been demonstrated to improve endothelial nitric oxide synthase (eNOS) activity, which played a crucial role in the regulation of angiogenesis. Diabetes Mellitus (DM) impairs eNOS activity. We tested the hypothesis that DM may retard unilateral hindlimb ischemia-induced angiogenesis by inhibiting eNOS in high-fat diet (HFD)/streptozocin (STZ) induced diabetic mice, and that TUS may reverse DM-related impairment of angiogenesis. C57BL/6 mice were allocated to four groups: (A) mice were fed standard diet (control); (B) mice were fed standard diet and treated with TUS (control+TUS); (C) type-2 DM mice were induced by HFD/STZ (diabetic); and (D) type-2 DM mice and treated with TUS (dabetic+TUS)...
2016: American Journal of Translational Research
Bruno Sciolla, Lester Cowell, Thibaut Dambry, Benoît Guibert, Philippe Delachartre
High-frequency 3-D ultrasound imaging is an informative tool for diagnosis, surgery planning and skin lesion examination. The purpose of this article was to describe a semi-automated segmentation tool providing easy access to the extent, shape and volume of a lesion. We propose an adaptive log-likelihood level-set segmentation procedure using non-parametric estimates of the intensity distribution. The algorithm has a single parameter to control the smoothness of the contour, and we describe how a fixed value yields satisfactory segmentation results with an average Dice coefficient of D = 0...
October 6, 2016: Ultrasound in Medicine & Biology
C Hernández-Ibáñez, N Blazquez-Sánchez, M Aguilar-Bernier, R Fúnez-Liébana, F Rivas-Ruiz, M de Troya-Martín
INTRODUCTION: Incisional biopsy may not always provide a correct classification of histologic subtypes of basal cell carcinoma (BCC). High-frequency ultrasound (HFUS) imaging of the skin is useful for the diagnosis and management of this tumor. OBJECTIVES: The main aim of this study was to compare the diagnostic value of HFUS compared with punch biopsy for the correct classification of histologic subtypes of primary BCC. We also analyzed the influence of tumor size and histologic subtype (single subtype vs...
October 5, 2016: Actas Dermo-sifiliográficas
Marcel Ivanov, Alexandru Budu, Hugh Sims-Williams, Ion Poeata
BACKGROUND: Our aim was to evaluate the utility of modern intraoperative ultrasound in the resection of a wide variety of spinal intradural pathological entities. MATERIALS AND METHODS: The authors evaluated patients with spinal cord pathology treated between January 2006 and September 2015. Intraoperative standard B-mode images were acquired using a 3.5-12 MHz US probes (linear and curvilinear) on various ultrasound machines. The benefits and disadvantages of intraoperative ultrasound (iUS) were assessed for each case...
October 3, 2016: World Neurosurgery
Anthony Blaeser, Hiroyuki Awano, Bo Wu, Qi-Long Lu
Mutations in the gene for fukutin-related protein represent a subset of muscular dystrophies known as dystroglycanopathies characterized by loss of functionally-glycosylated-alpha-dystroglycan and a wide range of dystrophic phenotypes. Mice generated by our lab containing the P448L mutation in the fukutin-related protein gene demonstrate the dystrophic phenotype similar to that of LGMD2I. Here we examined the morphology of the heart and diaphragm, focusing on pathology of diaphragm and cardiac function of the mutant mice for up to 12 months...
2016: PloS One
Thanh M Bui, Alain Coron, Jonathan Mamou, Emi Saegusa-Beecroft, Tadashi Yamaguchi, Eugene Yanagihara, Junji Machi, S Lori Bridal, Ernest J Feleppa
OBJECTIVE: To detect metastases in freshly excised human lymph nodes (LNs) using 3-dimensional (3D), high-frequency, quantitative ultrasound (QUS) methods, the LN parenchyma (LNP) must be segmented to preclude QUS analysis of data in regions outside the LNP and to compensate ultrasound attenuation effects due to overlying layers of LNP and residual perinodal fat (PNF). METHODS: After restoring saturated radio-frequency signals from PNF using an approach based on smoothing-cubic splines, the three regions, i...
September 28, 2016: IEEE Transactions on Bio-medical Engineering
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