Gas micronuclei that underlie decompression bubbles and decompression sickness have not been identified

摘要

Gas micronuclei are gas-filled voids in liquids from whichbubbles can form at low gas supersaturation. If water isdepleted of gas micronuclei, high gas supersaturation isrequired for bubble formation. This high gas supersaturationis required in part to overcome the Laplace pressure at thepoint of transition from dissolved gas to a bubble of perhapsnanometer-scale radius. The sum of gas and vapour partialpressures inside a spherical bubble (Pbub) of radius r exceedsthe ambient barometric pressure (Pamb) and is given by theYoung-LaPlace equation:(1)for a bubble not in contact with a solid surface. The secondterm on the right-hand side is the Laplace pressure across thegas-liquid interface due to surface tension (γ). For instance,for a surface tension characteristic of blood of 0.056 N·m-1,de novo formation of a bubble of r = 10 nm requires gassupersaturation exceeding 2γ/r = 11.2 MPa.