scholarly journals Efficacy Estimation of Microbubble-Assisted Local Sonothrombolysis Using a Catheter with a Series of Miniature Transducers

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 612
Author(s):  
Peiyang Li ◽  
Wenchang Huang ◽  
Jie Xu ◽  
Weiwei Shao ◽  
Yaoyao Cui
Keyword(s):  
Intravascular Ultrasound ◽  
High Frequency ◽  
Low Frequency ◽  
Clinical Applications ◽  
Clot Lysis ◽  
Low Intensity ◽  
Low Frequency Ultrasound ◽  
Low Intensity Ultrasound ◽  
Ultrasound Energy ◽  
Frequency Ultrasound

Intravascular ultrasound has good prospects for clinical applications in sonothrombolysis. The catheter-based side-looking intravascular ultrasound thrombolysis (e.g., Ekosonic catheters) used in clinical studies has a high frequency (2 MHz). The lower-frequency ultrasound requires a larger-diameter transducer. In our study, we designed and manufactured a small ultrasound-based prototype catheter that can emit a lower frequency ultrasound (1.1 MHz). In order to evaluate the safety and efficacy of local low-frequency ultrasound-enhanced thrombolysis, a microbubble (MB) was introduced to augment thrombolysis effect of locally delivered low-intensity ultrasound. The results demonstrated that combination of ultrasound and MB realized higher clot lysis than urokinase-only treatment (17.0% ± 1.2% vs. 14.9% ± 2.7%) under optimal ultrasound settings of 1.1 MHz, 0.414 MPa, 4.89 W/cm2, 5% duty cycle and MB concentration of 60 μg/mL. When urokinase was added, the fibrinolysis accelerated by MB and ultrasound resulted in a further increased thrombolysis rate that was more than two times than that of urokinase alone (36.7% ± 5.5% vs. 14.9% ± 2.7%). However, a great quantity of ultrasound energy was required to achieve substantial clot lysis without MB, leading to the situation that temperature accumulated inside the clot became harmful. We suggest that MB-assisted local sonothrombolysis be considered as adjuvant therapy of thrombolytic agents.

scholarly journals Ultrassom terapêutico para cicatrização de feridas: revisão sistemática

2017 ◽  
Vol 15 (3) ◽  
pp. 518-529
Author(s):  
Raciele Ivandra Guarda Korelo ◽  
Luiz Claudio Fernandes
Keyword(s):  
High Frequency ◽  
Low Frequency ◽  
High Frequency Ultrasound ◽  
Pulsed Ultrasound ◽  
Low Intensity Pulsed Ultrasound ◽  
Low Intensity ◽  
Low Frequency Ultrasound ◽  
Frequency Ultrasound

Introdução: o uso do ultrassom terapêutico (UST) para cicatrização de feridas ainda é discutido pela comunidade científica. Objetivo: determinar se o UST produz desfechos benéficos na cicatrização de feridas e quais tem sido os parâmetros utilizados para proporcionar melhor dose-resposta. Métodos: Foram pesquisadas as bases de dados PubMEd, SciELO e PEDro. Foram selecionados 19 ensaios clínicos, avaliados pelas escalas PEDro e JADAD. Resultados: dos 19 estudos, 8 relacionaram-se à aplicação do NCLFU (Noncontact Low Frequency Ultrasound) com evidência moderada para sua aplicação, 6 à aplicação do HFU (High Frequency Ultrasound) e 1 à aplicação de LIPUS (Low Intensity Pulsed Ultrasound), ambos com baixa evidência. Quanto a relação dose-resposta, não há concordância entre os estudos desta revisão. Conclusões: existe evidência moderada da NCLFU e limitada da HFU como recurso adjuvante para o tratamento de feridas, não sendo possível responder com clareza a melhor relação dose-resposta.

Biohydrogen Production by Co-Fermentation of Starch Wastewater and Sludge under Thermophilic Condition

2013 ◽  
Vol 724-725 ◽  
pp. 360-364 ◽  
Author(s):  
He Shan Zheng ◽  
Wan Qian Guo ◽  
Shan Shan Yang ◽  
Xiao Chi Feng ◽  
Xian Jiao Zhou ◽  
...  
Keyword(s):  
Low Frequency ◽  
Biohydrogen Production ◽  
Mixing Ratio ◽  
Thermophilic Enzyme ◽  
Ph Buffering ◽  
Starch Wastewater ◽  
Low Frequency Ultrasound ◽  
Thermophilic Condition ◽  
Low Intensity Ultrasound ◽  
Frequency Ultrasound

In this paper, the possibility and potential of biohydrogen production by co-fermentation of starch wastewater (SW) and WAS under thermophilic temperature was studied in batch fermentation tests. WAS was first pretreated by thermophilic enzyme together with low intensity ultrasound (LIU) to improve the biochemical degradability. Then After 8 h pretreatment, all soluble substances were much higher than raw sludge without pretreatment. In addition, the SCOD, carbohydrate and protein of the tests which were accelerated by low-frequency ultrasound were 11.5% 18.4%, 17.8% higher than the control, respectively. Results from the co-fermentation further demonstrated that the sludge had high pH buffering capacity. A mixing ratio of 1:1 was found to be the best among of all co-fermentation tests. Moreover it was proved in this study that hydrogen production by co-fermentation of starch wastewater and sludge was a promising technology to recovery energy from the waste.

scholarly journals Remote Excitation of Neuronal Circuits Using Low-Intensity, Low-Frequency Ultrasound

PLoS ONE ◽  
2008 ◽  
Vol 3 (10) ◽  
pp. e3511 ◽  
Author(s):  
William J. Tyler ◽  
Yusuf Tufail ◽  
Michael Finsterwald ◽  
Monica L. Tauchmann ◽  
Emily J. Olson ◽  
...  
Keyword(s):  
Low Frequency ◽  
Neuronal Circuits ◽  
Low Intensity ◽  
Low Frequency Ultrasound ◽  
Frequency Ultrasound

Ultrasound effects on the assembly of casein micelles in reconstituted skim milk

2013 ◽  
Vol 81 (2) ◽  
pp. 146-155 ◽  
Author(s):  
Zheng Liu ◽  
Pablo Juliano ◽  
Roderick PW Williams ◽  
Julie Niere ◽  
Mary Ann Augustin
Keyword(s):  
High Frequency ◽  
Skim Milk ◽  
Low Frequency ◽  
Casein Micelle ◽  
Casein Micelles ◽  
Specific Energy Input ◽  
Bulk Milk ◽  
Altered Protein ◽  
Low Frequency Ultrasound ◽  
Frequency Ultrasound

Reconstituted skim milks (10 % w/w total solids, pH 6·7–8·0) were ultrasonicated (20, 400 or 1600 kHz at a specific energy input of 286 kJ/kg) at a bulk milk temperature of <30 °C. Application of ultrasound to milk at different pH altered the assembly of the casein micelle in milk, with greater effects at higher pH and lower frequency. Low frequency ultrasound caused greater disruption of casein micelles causing release of protein from the micellar to the serum phase than high frequency. The released protein re-associated to form aggregates of smaller size but with surface charge similar to the casein micelles in the original milk. Ultrasound may be used as a physical intervention to alter the size of the micelles and the partitioning of caseins between the micellar and serum phases in milk. The altered protein equilibria induced by ultrasound treatment may have potential for the development of milk with novel functionality.

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