  This report presents some studies of the gauge/string theory correspondence,
a deep relation that is possible to establish between quantum field theories
with local gauge symmetry and superstring theories including gravity. In its
original version, known as AdS/CFT duality, the correspondence involves N=4
Super Yang-Mills theory in four space-time dimensions, which is a
superconformal theory with a high degree of supersymmetry, thus very far from
describing the physical world.
  We explore extensions of the correspondence towards less supersymmetric and
non-conformal gauge theories. Specifically, we study gauge theories in three
and four dimensions, with eight or four preserved supersymmetries and
exhibiting a scale anomaly, by means of supergravity solutions describing
D-brane configurations of type II string theory. We show how relevant
information on these gauge theories can be extracted from the dual classical
solutions, both at the perturbative (e.g. running coupling constant, chiral
anomaly) and non-perturbative level (e.g. effective superpotential).
