Search

Your search keyword '"TU Juan"' showing total 25 results
Start Over "TU Juan" Publisher iop publishing
25 results on '"TU Juan"'

1. Acoustic Gaussian-Airy beams

Author

Chen, Xizhou, primary, Ding, Suyu, additional, Wei, Qinran, additional, Tu, Juan, additional, Guo, Xiasheng, additional, and Zhang, Dong, additional

Published
2022
Full Text
View/download PDF

20. Microstreaming velocity field and shear stress created by an oscillating encapsulated microbubble near a cell membrane

Author

Zhang Dong, Guo Xia-Sheng, Wang Li, Xu Di, and Tu Juan

Subjects
Materials science, Bubble, General Physics and Astronomy, Cell membrane, Viscosity, Membrane, Nuclear magnetic resonance, medicine.anatomical_structure, Biophysics, Microbubbles, Shear stress, medicine, Elasticity (economics), Sonoporation
Abstract

Sonoporation mediated by microbubbles is being extensively studied as a promising technology to facilitate gene/drug delivery to cells. However, the theoretical study regarding the mechanisms involved in sonoporation is still in its infancy. Microstreaming generated by pulsating microbubble near the cell membrane is regarded as one of the most important mechanisms in the sonoporation process. Here, based on an encapsulated microbubble dynamic model with considering nonlinear rheological effects of both shell elasticity and viscosity, the microstreaming velocity field and shear stress generated by an oscillating microbubble near the cell membrane are theoretically simulated. Some factors that might affect the behaviors of microstreaming are thoroughly investigated, including the distance between the bubble center and cell membrane (d), shell elasticity (χ), and shell viscosity (κ). The results show that (i) the presence of cell membrane can result in asymmetric microstreaming velocity field, while the constrained effect of the membrane wall decays with increasing the bubble-cell distance; (ii) the bubble resonance frequency increases with the increase in d and χ, and the decrease in κ, although it is more dominated by the variation of shell elasticity; and (iii) the maximal microstreaming shear stress on the cell membrane increases rapidly with reducing the d, χ, and κ. The results suggest that microbubbles with softer and less viscous shell materials might be preferred to achieve more efficient sonoporation outcomes, and it is better to have bubbles located in the immediate vicinity of the cell membrane.

Published
2014
Full Text
View/download PDF

21. In vivo hyperthermia effect induced by high-intensity pulsed ultrasound.

Author

Cui Wei-Cheng, Tu Juan, Hwang Joo-Ha, Li Qian, Fan Ting-Bo, Zhang Dong, Chen Jing-Hai, and Chen Wei-Zhong

Subjects
ULTRASONICS, TEMPERATURE effect, IMMUNE response, FEVER, DRUG delivery systems, CELL death, VEINS, LABORATORY rabbits
Abstract

Hyperthermia effects (39-44 °C) induced by pulsed high-intensity focused ultrasound (HIFU) have been regarded as a promising therapeutic tool for boosting immune responses or enhancing drug delivery into a solid tumor. However, previous studies also reported that the cell death occurs when cells are maintained at 43 °C for more than 20 minutes. The aim of this study is to investigate thermal responses inside in vivo rabbit auricular veins exposed to pulsed HIFU (1.17 MHz, 5300 W/cm2, with relatively low-duty ratios (0.2%-4.3%). The results show that: (1) with constant pulse repetition frequency (PRF) (e.g., 1 Hz), the thermal responses inside the vessel will increase with the increasing duty ratio; (2) a temperature elevation to 43 °C can be identified at the duty ratio of 4.3%; (3) with constant duty ratios, the change of PRF will not significantly affect the temperature measurement in the vessel; (4) as the duty ratios lower than 4.3%, the presence of microbubbles will not significantly enhance the thermal responses in the vessel, but will facilitate HIFU-induced inertial cavitation events. [ABSTRACT FROM AUTHOR]

Published
2012
Full Text
View/download PDF

24. Real-Time Measurements and Modelling on Dynamic Behaviour of SonoVue Bubbles Based on Light Scattering Technology.

Author

Tu Juan, Crum and, and Wei Rongjue

Subjects
*TIME measurements, *PHYSICAL measurements, *LIGHT scattering, *FLUCTUATIONS (Physics)
Abstract

The dynamic behaviour of SonoVue microbubbles, a new generation ultrasound contrast agent, is investigated in real time with light scattering method. Highly diluted SonoVue microbubbles are injected into a diluted gel made of xanthan gum and water. The responses of individual SonoVue bubbles to driven ultrasound pulses are measured. Both linear and nonlinear bubble oscillations are observed and the results suggest that SonoVue microbubbles can generate strong nonlinear responses. By fitting the experimental data of individual bubble responses with Sarkar's model, the shell coating parameter of the bubbles and dilatational viscosity is estimated to be 7.0 nm*s*Pa. [ABSTRACT FROM AUTHOR]

Published
2008
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results