Self-assembling of atomic vacancies at an oxide/intermetallic alloy interface.

Oxide layers grown on the surface provide an effective way of protecting metallic materials against corrosion for sustainable use in a broad range of applications. However, the growth of cavities at the metal/oxide interface weakens the adherence of the protective layer and can promote its spallation under service conditions, as observed for alumina layers formed by selective oxidation of aluminide intermetallic alloys used in high-temperature applications. Here we show that direct atomic-scale observations of the interface between an ultrathin protective oxide layer (alumina) grown on an intermetallic titanium aluminide substrate (TiAl) can be performed with techniques sensitive to the topmost atomic layers at the surface.

Gonorrhea in the male: some aspects of treatment in Lebanon.

One hundred male patients with acute gonococcal urethritis were treated with various antibiotic and chemotherapeutic regimens. Pivampicillin, 1400 mg orally in two divided does at 5 hours' interval gave 100% cure in 60 patients. Gentamicin, 280 mg IM in one dose was equally efficaceous in 15 patients.