RG flows towards IR isolated fixed points: some type-0 samples

We perform here a critical analysis of some non-supersymmetric gravity solu tions in type-0B string theory. We first consider the most general configur ation of parallel N electric and M magnetic D3-branes. The field theory liv ing on their worldvolume is non-supersymmetric and non-conformal (if N not equal M) and has gauge group SU(N) x SU(M). We study the IR regime of the c onjectured dual gravity background. A fine tuned solution exists with an as ymptotically vanishing tachyon and a running dilaton, which could correspon d to a ow towards an IR isolated fixed point at strong coupling. This opens the question upon the possibility of extending AdS/CFT techniques to flows towards IR isolated fixed points. We then use D3-branes as probes of this and other type-0 backgrounds available in literature which cover the M = 0 (or N = 0) case. We shaw that for the fine tuned IR conformal solutions the stacks of parallel branes are plagued by instabilities, due to the repulsi ve force between branes of the same type. Curiously for a particular soluti on which could be dual to a confining gauge theory, the stack should instea d be stable.