We present a brief review of experimental results obtained in high Rey
nolds number flows using Helium gas as the working fluid. We focus on
measurements of the skewness and the flatness of the velocity derivati
ve, and in particular their evolution with the Reynolds number. A tran
sition, observed at R-lambda approximate to 700, is discussed. In the
second part, we analyze the structures associated with high velocity g
radients, which we identify as ''worms''; we finally present a detaile
d analysis of the evolution of their mean size, their number and their
velocity increment with Reynolds number. (C) Elsevier, Paris.