Remarks on the Computational Power of Some Restricted Variants of P Systems with Active Membranes

In this paper we consider three restricted variants of P systems with active membranes: (1) P systems using out communication rules only, (2) P systems using elementary membrane division and dissolution rules only, and (3) polarizationless P systems using dissolution and restricted evolution rules only. We show that every problem in P can be solved with uniform families of any of these variants. This, using known results on the upper bound of the computational power of variants (1) and (3) yields new characterizations of the class P. In the case of variant (2) we provide a further characterization of P by giving a semantic restriction on the computations of P systems of this varian

Rearrangement Reactions for the Synthesis of Some Oxa- and Aza-tricyclic Rings Heterocyclic Compounds

This review article describes the main results of our research during the last 5-6 years. A series of new rearrangement reactions was discovered and used for the synthesis of novel heterocyclic compounds: furo[2,3-f]isoquinolines, furo[3,2 -f]quinolines, benzo[c]xanthene, benzo[h]chromene, benzo[a]xanthene,  benzo[f]chromene, furo[2,3-f]isoquinoline, spirofuro[3,2-f]quinoline,  cycloalkanoindoles, and benzotriazines