introduction: acoustic transient cavitation is the primary mechanism of sonochemical reaction and has potential use for tumor treatment. in this study, the in vivo anti-tumor effect of simultaneous dual-frequency ultrasound at low-level intensity (isata < 6 w/cm2) was investigated in a spontaneous murine model of breast adenocarcinoma in balb/c mice. materials and methods: forty tumor bearing m...

Gassy and degassed aqueous solutions of DNA were treated ultrasonically while monitoring the field for discrate cavitation events. At irradiation intensities greater than about 500 W/cm 2, transient cavitation is shown to be responsible forthe observed reduction i molecular weight. At intensifies of200 to 288 W/cm 2, degradation of DNA was observed which did not depend upon transient cavitation.

This paper deals with a numerical and experimental study of ultrasound induced cavitation. On the basis of a computational analysis of Gilmore’s equation for the individual bubble dynamics, a slight decrease in the pressure radiated by a single bubble immediately before reaching the transient cavitation regime is predicted. Experiments presented in this paper confirm this observation. Therefore...

There are an increasing number of biological and bioengineering contexts in which cavitation is either utilized to create some desired effect or occurs as a byproduct of some other process. In this review an attempt will be made to describe a cross-section of these cavitation phenomena. In the byproduct category we describe some of the cavitation generated by head injuries and in artifical hear...

The physical principles underlying the oscillatory behavior of minute gas bubbles in liquids exposed to ultrasound are reviewed. Results from mathematical analyses suggest that these oscillations sometimes become unstable leading to transient cavitation in which a bubble violently collapses during a single acoustic half-cycle producing high temperatures and pressures. The role that micronuclei,...

Ultrasonic-assisted tungsten inert gas welding was carried out on a thin plate of 2195 Al-Li alloy, and the characteristics of the weld pores were analyzed in terms of their size and porosity. The effects of welding speed and ultrasonic power on the porosity and size of the pores were investigated. The pores were found to occur primarily adjacent to the surface of the weld. The porosity decreas...

We use stroboscopic quantitative phase microscopy to study cell deformation and the response to cavitation bubbles and transient shear stress resulting from laser-induced breakdown of an optically trapped nanoparticle. A bi-directional transient displacement of cytoplasm is observed during expansion and collapse of the cavitation bubble. In some cases, cell deformation is only observable at the...

The interaction between ultrasonic waves and biological tissues is the cause of cavitation phenomena. A primary scope of this paper was to set-up a measurement system for the generation of cavitation by means of forcing a low frequency (20 kHz). From the spectra and power density was evident the presence of the random component associated to the noise of cavitation was evident. For the estimate...

Cavitation decreases the hydraulic conductance of the xylem and has, therefore, detrimental effects on plant water balance. However, cavitation is also hypothesized to relieve water stress temporarily by releasing water from embolizing conduits to the transpiration stream. Stomatal closure in response to decreasing water potentials in order to avoid excessive cavitation has been well documented...