Many Ru and Os systems display photoactive (3)MLCT states. Systems activated by therapeutic window light in the absence of O(2) remain elusive. [(bpy)(2)Os(dpp)RhCl(2)(phen)](3+) photobinds and photocleaves DNA under red light in an oxygen independent manner, due to molecular design involving one Os chromophore coupled to a photoactive cis-Rh(III)Cl(2) moiety.

In the title compound, [Ni(C(22)H(19)N(2)OS)(2)], the Ni(II) atom is coordinated by the S and O atoms of two N-benzoyl-N',N'-dibenzyl-thio-ureate ligands in a slightly distorted square-planar geometry. The two O atoms are cis, as are the two S atoms.

Italy, fax (+39)–051–6447012, email [email protected]. [ * * ] We thank P. Procacci for useful discussions, and MIUR (PRIN " Cristalli Liquidi "), INSTM, and University of Bologna for financial support.

We have studied human spermatozoa from 24 normal, healthy unexposed men, 18 of whom were semen donors at the Sperm Bank in Turku, using multicolor fluorescence in situ hybridization with two chromosome-specific probes. The possible age-related increase in aneuploidy frequencies was assessed. Ten thousand spermatozoa were scored per individual for the presence of hyperploid, i.e., disomic and di...

Progressive telomere shortening occurs with division of normal human cells, and eventually leads to replicative senescence. The mechanism by which the shortened telomeres cause growth arrest is largely unknown. Transcriptional silencing of genes adjacent to telomeres, also called telomere position effect, has been hypothesized as a possible mechanism of telomere-mediated senescence. However, th...