Adsorption and Coupling of 4-aminophenol on Pt(111) surfaces.

We have deposited 4-aminophenol on Pt(111) surfaces in ultra-high vacuum and studied the strength of its adsorption through a combination of STM, LEED, XPS and ab initio calculations. Although an ordered (2√3×2√3)R30° phase appears, we have observed that molecule-substrate interaction dominates the adsorption geometry and properties of the system. At RT the high catalytic activity of Pt induces aminophenol to lose the H atom from the hydroxyl group, and a proportion of the molecules lose the complete hydroxyl group. After annealing above 420K, all deposited aminophenol molecules have lost the OH moiety and some hydrogen atoms from the amino groups. At this temperature, short single-molecule oligomer chains can be observed. These chains are the product of a new reaction that proceeds via the coupling of radical species that is favoured by surface diffusion.

Loss of silicone implants after subcutaneous mastectomy and reconstruction.

We studied 89 patients who had immediate or delayed placement of implants after subcutaneous mastectomies. The complications of infection, necrosis of the skin or areola, and extrusion of the prosthesis occurred in 28 percent of these patients, and the incidence was the same after immediate or delayed placement. Only one of the 45 patients who received prophylactic antibodies preoperatively developed an infection after insertion of the prosthesis. The late complications in some of these patients indicate the need for long-term follow-up.