Ionic Dissociation of SiCl : Formation of [SiL ]Cl with L=Dimethylphosphinic Acid.

Reactions of SiCl with R PO(OH) (R=Me, Cl) yield compounds with six-fold coordinated silicon atoms. Whereas R=Me afforded the hexacoordinated tetra-cationic silicon complex [Si(Me PO(OH)) ] with chloride counter-ions, R=Cl caused release of HCl with formation of a cyclic dimeric silicon complex [Si(Cl PO(OH))(Cl PO ) (μ-Cl PO )] with bridging bidentate dichlorophosphates.

Ecology and energetics of two Antarctic sponges.

Retention efficiencies, pumping and respiration rates of the two Antarctic sponge species Mycale acerata and Isodictya kerguelensis from Potter Cove, King George Island, were measured. None of the species reached a 100% retention efficiency at any given particle size. This is probably due to the sediment-laden environment in which the animals were dwelling.

Levels of cyclosporin in epidermis of treated psoriasis patients differentially inhibit growth of keratinocytes cultured in serum free versus serum containing media.

Cyclosporin A, which is a specific immunosuppressive compound, has recently been demonstrated to be of significant benefit in the treatment of psoriasis. Because hyperplasia is a major feature of psoriasis, we have investigated whether this drug acts directly to inhibit keratinocyte growth. We have determined the concentration range of cyclosporin in the epidermis of psoriatic patients undergoing cyclosporin therapy and the effect of this concentration range on the growth of cultured keratinocytes.