Fig. 2.

Ultrasonication-induced nucleation of amyloid fibrils. a Upon quasi-adiabatic collapse of the cavitation bubbles, temperature and pressure inside the cavity were increased up to several thousand Kelvin and several hundred atmospheric pressure, respectively, and temperature around the cavity (gas–liquid interface) increased up to several thousand Kelvin. Sonochemical oxidation of potassium iodide (KI) was caused by these transient microscopic fields, and the calorimetry method monitored an increase in the temperature of bulk water. Nucleation of amyloid fibrils could be efficiently generated around the cavitation bubbles during ultrasonication. b The formation of mouse prion protein (mPrP) amyloid fibirls at various positions of the ultrasonic stage. ThT fluorescence values at ultrasonic powers of >2.0 W (red), 1.0–2.0 W (black), and <1.0 W (blue). c Correlation between the nucleation time of amyloid fibrils and the ultrasonic power as estimated by the calorimetry method. Each bar represents the standard deviation (SD) of the nucleation times and ultrasonic power at each position. The curve was fitted using an exponential curve