Superconformal Gauge Theories and Non-Critical Superstrings
  We consider effective actions for six-dimensional non-critical superstrings. We show that the addition of $N$ units of R-R flux and of $N_f$ space-time filling D5-branes produces $AdS_5 \times S^1$ solutions with curvature comparable to the string scale. These solutions have the right structure to be dual to ${\cal N}=1$ supersymmetric SU(N) gauge theories with $N_f$ flavors. We further suggest bounds on the mass-squared of tachyonic fields in this background that should restrict the theory to the conformal window. 
Igor R. Klebanov and Juan M. Maldacena