Hypoxanthine will

Allopurinol (1H-pyrazolo[3,4-d]pyrimidin-4-ol) (Fig. 1) is a commonly used drug in the treatment of chronic gout or hyperuricaemia associated with leukaemia, radiotherapy, antineoplastic agents and treatment with diureticsconditions.1 Allopurinol is a structural isomer of hypoxanthine (a naturally occurring purine in the body) and acts to inhibit xanthine oxidase. In the presence of xanthine oxidase, allopurinol will be converted to alloxanthine (Fig. 2), after that the formation of uric acid from xanthine and hypoxanthine will be inhibited....

8p hoami_266 15-09-2011 60 7   Download

A subset M  E(G) of the edge set E(G) of a graph G is called a matching provided that no two edges in M have a vertex in common. A perfect matching M is a matching with the property that each vertex of G is incident with an edge in M. For k a positive integer, a graph G is k-extendable provided that G has a matching of size k and every matching in G of size at most k can be extended to a perfect matching in G.

15p thulanh6 14-09-2011 57 4   Download

Let N be a nilpotent group normal in a group G. Suppose that G acts transitively upon the points of a nite non-Desarguesian projective plane P. We prove that, if P has square order, then N must act semi-regularly on P. In addition we prove that if a nite non-Desarguesian projective plane P admits more than one nilpotent group which is regular on the points of P then P has non-square order and the automorphism group of P has odd order.

6p thulanh6 14-09-2011 63 5   Download

Let T be an innite regular tree and n a positive integer. Fix two vertices x and y in T . By a walk or a path between x and y we mean any nite sequence of edges that connect x and y in which backtrackings are allowed. There are many formulas in the literature which give the number of walks of length n between x and y, such as recurrence formulas, generating functions, Green functions, and others. Here we consider walks of length n between x and y which at a certain time follow a number of predetermined steps....

18p thulanh6 14-09-2011 38 5   Download