“…(For a recent theoretical work on this issue see, e.g., [11].) This is in fact the case with high-T c cuprates: recent measurements [12] have shown that the fluctuation diamagnetism (FD) of optimally doped YBa 2 Cu 3 O δ − 7 is not appreciably affected by the presence of magnetic impurities (either in the CuO 2 planes or intercalated between them). In striking contrast, the measurements in lanthanum with diluted magnetic (Pr) impurities presented in [13] have shown an important enhancement of FD, that is observed to be considerably larger than the theoretical results for three-dimensional isotropic superconductors [5,6,[14][15][16][17][18][19].…”