  The transport behavior and superconducting transition temperature Tc of
NdFe1-yRuyAsO0.89F0.11 have been studied for various y values. Because Ru
impurities are isoelectronic to host Fe atoms, we basically expect that the
number of electrons does not change with y, at least in the region of small y
values. The results indicate that the rate of Tc suppression by Ru atoms is too
small to be explained by the pair breaking effect of nonmagnetic impurities
expected for the S+- symmetry, confirming our previous results for Co doping.
