Recently, cavitation on the surface of mechanical heart valves has been studied as a cause of fractures occurring in implanted mechanical heart valves. The cause of cavitation in mechanical heart valves was investigated using the 25 mm Medtronic Hall valve and the 23 mm Omnicarbon valve. Closing of these valves in the mitral position was simulated in an electrohydraulic totally artificial heart...

Effects of mineral nutrition on susceptibility to cavitation were examined in four hybrid poplar clones. Two drought-sensitive and two drought-resistant hybrid clones of black cottonwood (Populus trichocarpa Torr. & Gray) and eastern cottonwood (P. deltoides Bartr.) were grown at three concentrations of nitrogen (N) applied factorially with two concentrations of phosphorus (P) in a greenhouse, ...

Hydroxyl radical (·OH) can rapidly react with biological macromolecules, organic and inorganic substances on account of its strong oxidizing property, so it is widely used in sewage treatment, chemiluminescence analysis, macromolecule modification other fields. The strengthening effect Hydrodynamic cavitation chemical reactions depends the number free radicals initiated by cavitation. These are...

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 cluster dynamics after the passage of a single pressure wave is studied for different concentrations of artificial cavitation nuclei (30 to 3x10(5) nuclei/ml). With increasing concentration of cavitation nuclei the lifetime of the cavitation cluster is prolonged. Additionally, it is found that the spatial extent of the cluster decreases with higher nuclei concentration. The experimen...

Eudicot angiosperms with greater vulnerability to xylem cavitation tend to have vessels with greater total area of inter-vessel pits, which inspired the 'rare pit' hypothesis: the more pits per vessel, by chance the leakier will be the vessel's single air-seeding pit and the lower the air-seeding threshold for cavitation to spread between vessels. Here, we demonstrate the feasibility of the hyp...

Oncolytic viruses (OV) could become the most powerful and selective cancer therapies. However, the limited transport of OV into and throughout tumors following intravenous injection means their clinical administration is often restricted to direct intratumoral dosing. Application of physical stimuli, such as focused ultrasound, offers a means of achieving enhanced mass transport. In particular,...

Cavitation and bubble dynamics have a wide range of practical applications in a range of disciplines, including hydraulic, mechanical and naval engineering, oil exploration, clinical medicine and sonochemistry. However, this paper focuses on how a fundamental concept, the Kelvin impulse, can provide practical insights into engineering and industrial design problems. The pathway is provided thro...

Cavitation appears to contribute to tissue injury in lithotripsy. Reports have shown that increasing pulse repetition frequency [(PRF) 0.5-100 Hz] increases tissue damage and increasing static pressure (1-3 bar) reduces cell damage without decreasing stone comminution. Our hypothesis is that overpressure or slow PRF causes unstabilized bubbles produced by one shock pulse to dissolve before they...

Focused ultrasound (FUS) in combination with microbubbles has been shown capable of delivering large molecules to the brain parenchyma through opening of the blood-brain barrier (BBB). However, the mechanism behind the opening remains unknown. To investigate the pressure threshold for inertial cavitation of preformed microbubbles during sonication, passive cavitation detection in conjunction wi...