  The AdS/CFT correspondence is an exact duality between string theory in
anti-de Sitter space and conformal field theories on its boundary. Inspired in
this correspondence some relations between strings and non conformal field
theories have been found. Exact dualities in the non conformal case are
intricate but approximations can reproduce important physical results. A simple
approximation consists in taking just a slice of the AdS space with a size
related to an energy scale. Here we will discuss how this approach can be used
to reproduce the scaling of high energy QCD scattering amplitudes. Also we show
that very simple estimates for glueball mass ratios can emerge from such an
approximation.
