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low frequency ultrasound

Julia Mariglia, Shadab Momin, Imogen R Coe, Raffi Karshafian
Ultrasonically-stimulated microbubbles enhance the therapeutic effects of various chemotherapy drugs. However, the application of ultrasound and microbubbles (USMB) for enhancing the therapeutic effect of nucleoside analogs, which are used as front-line treatments in a range of cancers, and its underlying mechanism is not well understood. This study investigated the effect of gemcitabine, a nucleoside analog drug, in combination with USMB in increasing cell cytotoxicity relative to either treatment alone in BxPC3 pancreatic cancer cells...
May 5, 2018: Ultrasonics
Ranran Zhao, Xiaolong Liang, Bo Zhao, Min Chen, Renfa Liu, Sujuan Sun, Xiuli Yue, Shumin Wang
To improve the non-invasive therapeutic efficacy for ER positive breast cancer (ER+ BC), we fabricated a multifunctional FOXA1 loaded porphyrin microbubble to combine photodynamic therapy (PDT) and gene therapy of FOXA1 knockdown (KD) with ultrasound targeted microbubble destruction (UTMD) technology under the guidance of contrast enhanced ultrasound (CEUS). Cationic porphyrin microbubbles (CpMBs) were firstly fabricated from a porphyrin grafted lipid with two cationic amino groups (PGL-NH2) and fluorocarbon inert gas of C3 F8 ...
May 3, 2018: Biomaterials
Qiuju Jiang, Guofeng Li, Huixia Zhao, Wenlong Sheng, Lan Yue, Min Su, Shijun Weng, Leanne Lai-Hang Chan, Qifa Zhou, Mark S Humayun, Weibao Qiu, Hairong Zheng
Significant progress has been made recently in treating neurological blindness using implantable visual prostheses. However, implantable medical devices are highly invasive and subject to many safety, efficacy, and cost issues. The discovery that ultrasound (US) may be useful as a noninvasive neuromodulation tool has aroused great interest in the field of acoustic retinal prostheses (ARPs). We have investigated the responsiveness of rat retinal ganglion cells (RGCs) to low-frequency focused US stimulation (LFUS) at 2...
May 2018: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Xiao Tan, Xiaoqian Shu, Jiujia Guo, Keshab Parajuli, Xidong Zhang, Zhipeng Duan
Ultrasound can be used to induce cell resonance and cavitation to inhibit cyanobacterial growth, but it can also lead to increase in dissolved nutrients because of cell disruption. This study investigated the process from cell inactivation to disruption of Microcystis aeruginosa. Algal cells were sonicated (at 35 kHz) under various intensities and durations. Results showed that chlorophyll a content and F v /F m values decreased slightly within the first 5 min. Superoxide dismutase activity was stimulated and its peak value appeared at the fifth minute...
May 9, 2018: Bulletin of Environmental Contamination and Toxicology
Nasim Karami, Parviz Mohammadi, Aliakbar Zinatizadeh, Farzaneh Falahi, Nasrin Aghamohammadi
The biomass concentration of conventional activated sludge (CAS) process due to low sludge sedimentation in clarifiers is limited to 3000 mg/L. In this study, high-frequency ultrasound wave (1.8 MHz) was applied to enhance the CAS process performance using high Mixed Liquor Suspended Solid (MLSS) concentration. The study conducted using a pilot scale CAS bioreactor (with and without ultrasound) and their performance for treating a hospital wastewater were compared. Experimental conditions were designed based on a Central Composite Design (CCD)...
September 2018: Ultrasonics Sonochemistry
Hideyuki Nomura, Hideo Adachi, Tomoo Kamakura
When using high-frequency (HF) ultrasound in sonography, attenuation due to the viscosity of the medium limits the available imaging depth, and strong reflection and scattering from hard tissue, such as bone, render biological diagnosis very difficult. In order to resolve these problems, the feasibility of low-frequency (LF) parametric ultrasound imaging with high directivity was explored in the present study. A pulse compression technique was applied to chirp-modulated parametric ultrasound waves in the frequency band of 100-500 kHz generated from modulated primary ultrasound waves with a center frequency of 2...
April 23, 2018: Ultrasonics
Chen Bai, Meiling Ji, Ayache Bouakaz, Yujin Zong, Mingxi Wan
For investigating human transcranial ultrasound imaging (TUI) through the temporal bone, an intact human skull is needed. Since it is complex and expensive to obtain one, it requires that experiments are performed without excision or abrasion of the skull. Besides, to mimic blood circulation for the vessel target, cellulose tubes generally fit the vessel simulation with straight linear features. These issues, which limit experimental studies, can be overcome by designing a 3-D-printed skull model with acoustic and dimensional properties that match a real skull and a vessel model with curve and bifurcation...
May 2018: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
Mert Tuzer, Abdulkadir Yazıcı, Rüştü Türkay, Michael Boyman, Burak Acar
PURPOSE: To develop a medical ultrasound (US) simulation method using T1-weighted magnetic resonance images (MRI) as the input that offers a compromise between low-cost ray-based and high-cost realistic wave-based simulations. METHODS: The proposed method uses a novel multi-ray image formation approach with a virtual phased array transducer probe. A domain model is built from input MR images. Multiple virtual acoustic rays are emerged from each element of the linear transducer array...
May 4, 2018: International Journal of Computer Assisted Radiology and Surgery
Yehai Li, Kai Wang, Zhongqing Su
Self-sensing capability of composite materials has been the core of intensive research over the years and particularly boosted up by the recent quantum leap in nanotechnology. The capacity of most existing self-sensing approaches is restricted to static strains or low-frequency structural vibration. In this study, a new breed of functionalized epoxy-based composites is developed and fabricated, with a graphene nanoparticle-enriched, dispersed sensing network, whereby to self-perceive broadband elastic disturbance from static strains, through low-frequency vibration to guided waves in an ultrasonic regime...
May 2, 2018: Sensors
Zhili Meng, Zhiwei Zhou, Dan Zheng, Lujian Liu, Jun Dong, Yanling Yang, Xing Li, Tingting Zhang
Sludge dewatering has proven to be an effective method to reduce the volume of sludge. In this study, drinking water treatment sludge (DWTS) was treated by ultra-sonication under variable conditions comparing two sonoreactor types (bath and probe), four frequencies (25, 40, 68, 160 kHz) and four energy density levels (0.03, 1, 3, 5 W/mL). The effects of these conditions were studied using specific resistance to filtration and capillary suction time as measures of dewaterability, and floc size, the Brunauer, Emmett and Teller (BET) specific surface area and Zeta potential to determine treated sludge characteristics...
July 2018: Ultrasonics Sonochemistry
Shweta V Pawar, Virendra K Rathod
Low energy ultrasound irradiation was used to enhance co-production of enzymes uricase and alkaline protease using Bacillus licheniformis NRRL 14209. Production of uricase and alkaline protease was evaluated for different ultrasound parameters such as ultrasound power, time of irradiation, duty cycle and growth stage of organisms at which irradiation is carried out. Maximum uricase production of 0.825 U/mL and alkaline protease of 0.646 U/mL have been obtained when fermentation broth was irradiated at 6 h of growth stage with 60 W power for 15 min of duration having 40% of duty cycle...
July 2018: Ultrasonics Sonochemistry
Olivier Authier, Hind Ouhabaz, Stefano Bedogni
CO2 capture and utilization (CCU) is a process that captures CO2 emissions from sources such as fossil fuel power plants and reuses them so that they will not enter the atmosphere. Among the various ways of recycling CO2 , reduction reactions are extensively studied at lab-scale. However, CO2 reduction by standard methods is difficult. Sonochemistry may be used in CO2 gas mixtures bubbled through water subjected to ultrasound waves. Indeed, the sonochemical reduction of CO2 in water has been already investigated by some authors, showing that fuel species (CO and H2 ) are obtained in the final products...
July 2018: Ultrasonics Sonochemistry
Fabio Parazzini, Maria Pina Frattaruolo, Francesca Chiaffarino, Dhouha Dridi, Elena Roncella, Paolo Vercellini
The reported frequency of malignant diseases in unilocular cysts varies in different studies, giving conflicting results. To quantify the risk of malignancies among echoic and anechoic unilocular adnexal cysts, in premenopausal and postmenopausal women, we performed a PubMed/MEDLINE search of papers published in English evaluating the histopathological diagnoses of removed ovarian cysts diagnosed as simple unilocular cysts at pre-operative ultrasound examination. From 34 selected publications, we extracted data on ovarian malignancy in the total series, and separately for premenopausal and postmenopausal women, and women with cysts < 5 cm and  ≥5 cm in diameter...
April 18, 2018: European Journal of Obstetrics, Gynecology, and Reproductive Biology
Annika Bickford Kay, Sarah Majercik, Jeffrey Sorensen, Scott C Woller, Scott M Stevens, Thomas W White, David S Morris, Margaret Baldwin, Joseph R Bledsoe
BACKGROUND: Venous thromboembolism is a cause of morbidity and mortality in trauma patients. Chemoprophylaxis with low-molecular-weight heparin at a standardized dose is recommended. Conventional chemoprophylaxis may be inadequate. We hypothesized that a weight-adjusted enoxaparin prophylaxis regimen would reduce the frequency of venous thromboembolism in hospitalized trauma patients and at 90-day follow-up. METHODS: This prospective, randomized pilot study enrolled adult patients admitted to a level 1 trauma center between July 2013 and January 2015...
April 23, 2018: Surgery
Dan Chen, Haiying Guo
OBJECTIVE: To compare the therapeutic effects on dysphagia in post-stroke pseudobulbar palsy between the combined treatment with acupuncture and rehabilitation training and the combined treatment with low-frequency electrical therapy and rehabilitation training and to explore its more effective therapy, using the ultrasonographic examination. METHODS: A total of 60 patients of dysphagia in post-stroke pseudobulbar palsy were randomly assigned into an observation group and a control group, 30 cases in each one...
April 12, 2018: Zhongguo Zhen Jiu, Chinese Acupuncture & Moxibustion
Sangeet Ghai, Nathan Perlis, Uri Lindner, Eugen Hlasny, Masoom A Haider, Antonio Finelli, Alexandre R Zlotta, Girish S Kulkarni, Theodorus H van der Kwast, Stuart A McCluskey, Walter Kucharczyk, John Trachtenberg
OBJECTIVES: To evaluate the feasibility and safety of focal therapy for low-intermediate risk prostate cancer (PCa) with magnetic resonance-guided high frequency focused ultrasound (MRgFUS) METHODS: This IRB-approved phase 1 prospective study enrolled eight patients with prostate specific antigen (PSA) ≤ 10 ng/ml, ≤ cT2a and Gleason score ≤ 7 (4 + 3) disease following informed consent. Under MRI guidance, focused high frequency ultrasound energy was delivered to ablate the target tissue...
April 25, 2018: European Radiology
Shanshan Zhang, Yi Xu, Xiulan Han, Wen Wu, Yan Tang, Chuhuai Wang
Surface electromyography (sEMG) studies have indicated that chronic low back pain (cLBP) involves altered electromyographic activity and morphological structure of the lumbar multifidus (LM) beyond pain perception; however, most studies have evaluated the superficial lumbar multifidus. It is difficult to record electromyography (EMG) signals from the deep multifidus (DM) to determine the neuromuscular activation patterns, making it difficult to determine the relationship between functional and structural changes in cLBP...
April 25, 2018: Scientific Reports
A L Nikolaev, A V Gopin, A V Severin, V N Rudin, M A Mironov, N V Dezhkunov
The size control of materials is of great importance in research and technology because materials of different size and shape have different properties and applications. This paper focuses on the synthesis of hydroxyapatite in ultrasound fields of different frequencies and intensities with the aim to find the conditions which allow control of the particles size. The results are evaluated by X-ray diffraction, Transmission Electron Microscopy, morphological and sedimentation analyses. It is shown that the hydroxyapatite particles synthesized at low intensity non-cavitation regime of ultrasound have smaller size than those prepared at high intensity cavitation regime...
June 2018: Ultrasonics Sonochemistry
Zahra Mohammadi, Mohammad H Entezari
In this research, a facile, one step and eco-friendly sonochemical rout was utilized to the synthesis of a new nanocomposite by Ag nanoparticle anchored on reduced graphene oxide (rGO-Ag-U). Sonication was carried out by using low frequency ultrasound (20 kHz) under ambient condition. In this way, graphene oxide and Ag+ ions simultaneously reduced by polyol without using any additional reactants or capping agents. The polyol serves as both solvent and low toxic reducing agent. To achieve the best synthesis condition of rGO-Ag-U nanocomposite, the effects of irradiation time, ultrasonic amplitude and reaction temperature were investigated...
June 2018: Ultrasonics Sonochemistry
Francesca Parisi, Melek Rousian, Régine P M Steegers-Theunissen, Anton H J Koning, Sten P Willemsen, Jeanne H M de Vries, Irene Cetin, Eric A P Steegers
BACKGROUND/OBJECTIVES: Maternal dietary patterns were associated with embryonic growth and congenital anomalies. We aim to evaluate associations between early first trimester maternal dietary patterns and embryonic morphological development among pregnancies with non-malformed outcome. SUBJECTS/METHODS: A total of 228 strictly dated, singleton pregnancies without congenital malformations were enrolled in a periconceptional hospital-based cohort. Principal component analysis was performed to extract early first trimester maternal dietary patterns from food frequency questionnaires...
April 20, 2018: European Journal of Clinical Nutrition
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