keyword
MENU ▼
Read by QxMD icon Read
search

low frequency ultrasound

keyword
https://www.readbyqxmd.com/read/28440041/ultrasound-assisted-versus-conventional-catheter-directed-thrombolysis-for-acute-ilio-femoral-deep-vein-thrombosis-one-year-follow-up-data-of-a-randomized-controlled-trial
#1
Rolf P Engelberger, Anna Stuck, David Spirk, Torsten Willenberg, Axel Haine, Daniel Périard, Iris Baumgartner, Nils Kucher
BACKGROUND: In patients with acute ilio-femoral deep vein thrombosis (IFDVT), catheter-directed thrombolysis (CDT) aims to prevent the post-thrombotic syndrome (PTS). Adding intravascular high-frequency, low-power ultrasound energy to CDT does not seem to improve the immediate thrombolysis results but its impact on clinical outcomes at 12 months is not known. PATIENTS/METHODS: In this randomized-controlled trial, 48 patients (mean age 50±21 years, 52% women) with acute IFDVT were randomized to conventional CDT (n=24) or ultrasound-assisted CDT (USAT; n=24)...
April 25, 2017: Journal of Thrombosis and Haemostasis: JTH
https://www.readbyqxmd.com/read/28436918/an-integrated-and-highly-sensitive-ultrafast-acoustoelectric-imaging-system-for-biomedical-applications
#2
Beatrice Berthon, Pierre-Marc Dansette, Mickael Tanter, Mathieu Pernot, Jean Provost
PURPOSE: Direct imaging of cardiac electrical activation is crucial to better understand and diagnose diseases linked to arrhythmias. This work presents an Ultrafast Acoustoelectric Imaging (UAI) system for direct and non-invasive ultrafast mapping of propagating current densities. MATERIALS AND METHODS: Acoustoelectric imaging is based on the acoustoelectric effect, the modulation of the medium's electrical impedance by a propagating ultrasonic wave. UAI triggers this effect with plane wave emissions to image current densities...
April 24, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28434880/ultrasound-assisted-extraction-of-rare-earth-elements-from-carbonatite-rocks
#3
Lisarb O Diehl, Thais L Gatiboni, Paola A Mello, Edson I Muller, Fabio A Duarte, Erico M M Flores
In view of the increasing demand for rare-earth elements (REE) in many areas of high technology, alternative methods for the extraction of these elements have been developed. In this work, a process based on the use of ultrasound for the extraction of REE from carbonatite (an igneous rock) is proposed to avoid the use of concentrated reagents, high temperature and excessive extraction time. In this pioneer work for REE extraction from carbonatite rocks in a preliminary investigation, ultrasonic baths, cup horn systems or ultrasound probes operating at different frequencies and power were evaluated...
April 12, 2017: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/28433437/optimal-ultrasound-exposure-conditions-for-maximizing-c2c12-muscle-cell-proliferation-and-differentiation
#4
Alice Rita Salgarella, Andrea Cafarelli, Leonardo Ricotti, Lorenzo Capineri, Paolo Dario, Arianna Menciassi
Described here is an in vitro systematic investigation of the effects on C2C12 myoblasts of exposure to finely controlled and repeatable low-intensity pulsed ultrasound of different frequencies (500 kHz, 1 MHz, 3 MHz and 5 MHz) and different intensities (250, 500 and 1000 mW/cm(2)). An in-house stimulation system and an ultrasound-transparent cell culture well minimized reflections and attenuations, allowing precise control of ultrasound delivery. Results indicated that a 3 MHz stimulation at 1 W/cm(2) intensity maximized cell proliferation in comparison with the other exposure conditions and untreated controls...
April 19, 2017: Ultrasound in Medicine & Biology
https://www.readbyqxmd.com/read/28427670/estimation-of-the-distribution-of-low-intensity-ultrasound-mechanical-index-as-a-parameter-affecting-the-proliferation-of-spermatogonia-stem-cells-in-vitro
#5
Zeinab Hormozi Moghaddam, Manijhe Mokhtari-Dizaji, Mansoureh Movahedin, Mohammad Ehsan Ravari
Considering the use of physical and mechanical stimulation, such as low-intensity ultrasound for proliferation and differentiation of stem cells, it is essential to understand the physical and acoustical mechanisms of acoustic waves in vitro. Mechanical index is used for quantifying acoustic cavitation and the relationship between acoustic pressure and the frequency. In this study, modeling of the mechanical index was applied to provide treatment protocol and to understand the effective physical processes on reproducibility of stem cells...
July 2017: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/28427664/ultrasonic-irradiation-of-low-intensity-with-a-mode-of-sweeping-frequency-enhances-the-membrane-permeability-and-cell-growth-rate-of-candida-tropicalis
#6
Guoping Huang, Yingxiu Tang, Ling Sun, Huan Xing, Haile Ma, Ronghai He
Here we report the enhancement of both cellular permeability and cell growth rate of Candida tropicalis after treatment with the ultrasonic irradiation of low intensity using a mode of sweeping frequency (UILS) generated by a self-developed ultrasonic device in our lab. After the ultrasonic treatment, remarkable biomass enhancement of the yeast was observed; the hyphae became significantly longer; the seeped cellular protein and nucleic acid from the yeast increased and the cellular Ca(2+) content became lower...
July 2017: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/28427652/ultrasonic-modification-of-starch-impact-on-granules-porosity
#7
Monika Sujka
Rice, corn, wheat, and potato starch granules suspended in water or ethanol were treated with ultrasounds at frequency of 20kHz and power 170W for 30min. Porosity of starch was investigated in terms of specific surface area (SBET), average pore size and pore size distribution using low-temperature nitrogen adsorption method. The significant increase of SBET was noted for all the studied starches sonicated in water and for potato starch modified in ethanol. Ultrasonic treatment influenced the average diameter of mesopores (2nm<width<50nm) differently...
July 2017: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/28427629/development-of-a-novel-folate-modified-nanobubbles-with-improved-targeting-ability-to-tumor-cells
#8
Sujuan Duan, Lu Guo, Dandan Shi, Mengmeng Shang, Dong Meng, Jie Li
Conjugation of folate (FOL) to nanobubbles could enhance the selective targeting to tumors expressing high levels of folate receptor (FR). To further improve the selective targeting ability of FOL-modified nanobubbles, a novel FOL-targeted nanobubble ((FOL)2-NB) with increasing FOL content (accomplished by linking two FOL molecules per DSPE-PEG2000 chain) was synthesized, through the methods of mechanical shaking and low-speed centrifugation based on lipid-stabilized perfluoropropane. The bubble size and distribution range were measured by dynamic light scattering (DLS)...
July 2017: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/28427611/experimental-study-on-the-influence-of-low-frequency-and-low-intensity-ultrasound-on-the-permeability-of-the-mycobacterium-smegmatis-cytoderm-and-potentiation-with-levofloxacin
#9
Yu Dong, Hang Su, Hexun Jiang, Huimin Zheng, Yonghong Du, Junru Wu, Dairong Li
Tuberculosis is an infectious disease caused by the bacterium M. tuberculosis. The aim of this study was to investigate the bactericidal effect and underlying mechanisms of low-frequency and low-intensity ultrasound combined with levofloxacin treatment against M. smegmatis (a surrogate of M. tuberculosis). As part of this study, M. smegmatis was continuously irradiated with low frequency ultrasound (42kHz) using several different doses whereby both intensity (0.138, 0.190 and 0.329W/cm(2)) and exposure time (5, 15 and 20min) were varied...
July 2017: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/28420236/human-hepatocarcinoma-cell-targeting-by-glypican-3-ligand-peptide-functionalized-silica-nanoparticles-implications-for-ultrasound-molecular-imaging
#10
Marco Di Paola, Alessandra Quarta, Francesco Conversano, Enzo Antonio Sbenaglia, Simona Bettini, Ludovico Valli, Giuseppe Gigli, Sergio Casciaro
Silica nanoparticles (SiNPs) are widely studied nanomaterials for their potential employment in advanced biomedical applications, such as selective molecular imaging and targeted drug delivery. SiNPs are generally low cost and highly biocompatible, can be easily functionalized with a wide variety of functional ligands, and have been demonstrated to be effective in enhancing ultrasound contrast at clinical diagnostic frequencies. Therefore, SiNPs might be used as contrast agents in echographic imaging. In this work, we have developed a SiNPs-based system for the in vitro molecular imaging of hepatocellular carcinoma cells that express high levels of glypican-3 protein (GPC-3) on their surface...
April 27, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28405263/direct-contact-low-frequency-ultrasound-clearance-of-biofilm-from-metallic-implant-materials
#11
Mark S Granick, Chaitra Paribathan, Mayilvahanan Shanmugam, Narayanan Ramasubbu
Introduction: Biofilms are recognized as a significant deterrent to wound healing and to the management of exposed or infected surgical implants. Biofilms can be disrupted by a variety of enzymatic and mechanical interventions. This experiment was designed to determine whether direct-contact low-frequency ultrasound has the ability to clear biofilms and what then happens to the released bacteria. Methods:Staphylococcus epidermidis biofilm was grown on the surfaces of metallic discs composed of titanium and stainless steel, comparable with the alloys used in surgical implants...
2017: Eplasty
https://www.readbyqxmd.com/read/28392000/swave-imaging-of-placental-elasticity-and-viscosity-proof-of-concept
#12
Jeffrey M Abeysekera, Manyou Ma, Mehran Pesteie, Jefferson Terry, Denise Pugash, Jennifer A Hutcheon, Chantal Mayer, Lutz Lampe, Septimiu Salcudean, Robert Rohling
The placenta is the interface between the fetus and the mother and is vital for fetal development. Ultrasound elastography provides a non-invasive way to examine in vivo the stiffness of the placenta; increased stiffness has previously been linked to fetal growth restriction. This study used a previously developed dynamic elastography method, called shear wave absolute vibro-elastography, to study 61 post-delivery clinically normal placentas. The shear wave speeds in the placenta were recorded under five different low-frequency mechanical excitations...
April 6, 2017: Ultrasound in Medicine & Biology
https://www.readbyqxmd.com/read/28391195/development-of-a-low-complexity-cost-effective-digital-beamformer-architecture-for-high-frequency-ultrasound-imaging
#13
Changhan Yoon, Hyung Ham Kim, K K Shung
This paper presents a low-complexity, cost-effective digital beamformer architecture for a high-frequency ultrasound imaging system. The proposed beamformer uses a look-up-table (LUT) and linear interpolation methods for computing the dynamic receive focusing delays and a post-filtering technique to minimize hardware complexity. In the post-filtering technique, channel radio-frequency (RF) data having the same fractional delay (i.e., 16f0 resolution) are aggregated prior to interpolation. Thus, only four polyphase structure filters are required in the developed beamformer...
April 4, 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/28382132/monitoring-of-blood-vessel-density-using-contrast-enhanced-high-frequency-ultrasound-may-facilitate-early-diagnosis-of-lymph-node-metastasis
#14
Takuma Sato, Tomoaki Takemura, Tomoki Ouchi, Shiro Mori, Maya Sakamoto, Yoichi Arai, Tetsuya Kodama
Time-dependent alterations in the ultrasonography characteristics of lymph nodes during early-stage metastasis have not been compared with those of tumor-draining lymph nodes that do not develop tumor; this is partly due to the absence of an appropriate experimental model. In a previous study of lymph nodes with experimental early-stage metastasis, we used contrast-enhanced high-frequency ultrasound to demonstrate that an increase in lymph node blood vessel density preceded any changes in lymph node volume...
2017: Journal of Cancer
https://www.readbyqxmd.com/read/28377036/regression-patterns-of-iris-melanoma-after-palladium-103-103-pd-plaque-brachytherapy
#15
Sonal S Chaugule, Paul T Finger
PURPOSE: To evaluate the patterns of regression of iris melanoma after treatment with palladium-103 ((103)Pd) plaque brachytherapy. DESIGN: Retrospective, nonrandomized, interventional case series. PARTICIPANTS: Fifty patients with primary malignant melanoma of the iris. METHODS: Palladium-103 plaque brachytherapy. MAIN OUTCOME MEASURES: Changes in tumor size, pigmentation, and vascularity; incidence of iris neovascularization; and radiation-related complications...
April 1, 2017: Ophthalmology
https://www.readbyqxmd.com/read/28375081/high-frequency-ultrasound-features-and-pathological-characteristics-of-medullary-thyroid-carcinoma
#16
Hua Wang, Mengmeng Liu, Jianqiu Yang, Yimin Song
To study high-frequency ultrasound features and pathological characteristics of medullary thyroid carcinoma (medullary thyroid carcinoma, MTC) with the purpose to improve the diagnostic accuracy of this disease. The clinical data of 20 cases of patients with MTC confirmed by the clinical surgery were retrospectively analyzed. And the high-frequency ultrasound features were analyzed and compared with the pathological characteristics. There were 16 cases with tumor invasion into one side of the thyroid gland; 17 cases with tumor in the middle-upper pole of the thyroid gland...
November 2016: Pakistan Journal of Pharmaceutical Sciences
https://www.readbyqxmd.com/read/28358681/fast-nonlinear-ultrasound-propagation-simulation-using-a-slowly-varying-envelope-approximation
#17
Francois Varray, Matthieu Toulemonde, Adeline Bernard, Olivier Basset, Christian Cachard
Medical systems usually consider linear propagation of ultrasound, an approximation of reality. However, numerous studies have attempted to accurately simulate the nonlinear pressure wave distortion and to evaluate the contribution of harmonic frequencies. In such simulations, the computation time is very large, except for the method based on the angular spectrum scheme where the derivative order is reduced using the Fourier transform. However, the harmonic computation is usually limited to the second harmonic because of quasi-linear approximation...
March 24, 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/28350703/rf-safety-analysis-of-a-novel-ultra-wideband-fetal-monitoring-system
#18
Jerrold T Bushberg, J Paul Tupin
The LifeWave Ultra-Wideband RF sensor (LWUWBS) is a monitoring solution for a variety of physiologic assessment applications, including maternal fetal monitoring in both the antepartum and intrapartum periods. The system uses extremely low power radio frequency (RF) ultra-wide band (UWB) signals to provide continuous fetal heart rate and contractions monitoring during labor and delivery. Even with the incorporation of three very conservative assumptions, (1) concentration of the RF energy in 1 cm, (2) minimal (2...
May 2017: Health Physics
https://www.readbyqxmd.com/read/28349953/observation-of-low-loss-broadband-supermode-propagation-in-coupled-acoustic-waveguide-complex
#19
Ya-Xi Shen, Yu-Gui Peng, Xin-Cheng Chen, De-Gang Zhao, Xue-Feng Zhu
We investigate analytically, numerically, and experimentally the low-loss supermode propagation in a coupled acoustic waveguide complex within a broadband. The waveguide complex is implemented with air channels coupled via an ultrathin metafluid layer. We analytically derive the field distribution of incident sound needed for producing acoustic supermodes, and verify the periodically revival propagation in coupled waveguide systems numerically and experimentally. We find out that the supermode wavelength becomes longer for higher mode order or lower frequency...
March 28, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28342758/effects-of-low-frequency-ultrasound-on-heterogenous-deacetylation-of-chitin
#20
Ngo Thi Hoai Duong, Ngo Dang Nghia
The effects of low frequency ultrasound to the heterogeneous deacetylation of chitin from the shell of white shrimp (Penaeus vannamei) were examined. The deacetylation process was carried out in the range of NaOH concentrations from 35% to 65% (w/w) with and without the ultrasound in the frequency of 37kHz, RMS=300W. The chitosan obtained was characterized in the degree of deacetylation, solubility, FT-IR and X-ray diffraction. The results showed that the behaviors of the deacetylation in two cases, with and without ultrasound, were similar but the ultrasound enhanced the deacetylation rate and therefore reduced the time of the reaction to get the same degree of deacetylation...
March 22, 2017: International Journal of Biological Macromolecules
keyword
keyword
61039
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"