Various TEM images of freeze-fractured replica of pure O2 MNBs in pure water. Spherical or oval NBs of (a) 500 nm in diameter or (b) 200 nm in diameter were located in ice crystallites (smooth surface) or on their grain boundaries. (c) The replica sample of pure water without aeration was shown as a control. Each scale bar indicates 500 nm.
Uchida et al. Nanoscale Research Letters 2011 6:295 doi:10.1186/1556-276X-6-295