RESUMEN
Self-assembling systems of colloidal spheres are widely used as templates for the structured deposition of metals and semiconductors. Multilayer samples of ordered polystyrene spheres are prepared by a flow induced process. The subsequent surface activation by a dielectric barrier discharge in oxygen is followed by the fabrication of protecting polysiloxane layers. Electrochemical deposition of copper is used to test the stability of the pre-treated colloidal crystal. The arrangement of the spheres is preserved during the deposition process, due to the polysiloxane layer. The results of the consecutive preparation steps are investigated concerning topographical and chemical changes by atomic force microscopy, scanning electron microscopy and X-ray photoelectron spectroscopy.
Asunto(s)
Coloides/síntesis química , Cristalización/métodos , Galvanoplastia/métodos , Nanopartículas/química , Nanopartículas/ultraestructura , Gases em Plasma/química , Poliestirenos/síntesis química , Ensayo de Materiales , Tamaño de la Partícula , Propiedades de SuperficieRESUMEN
Three out of ten young to adult wanderoos (M. silenus) of a breeding colony at the Rheine Zoo died within two days from a peracute illness, characterized by salivation, vomiting, apathy and minor CNS symptoms. Streptococcus equi ssp. zooepidemicus was isolated in pure cultures from all organs of two animals investigated bacteriologically. The strains were penicillin-susceptible, and penicillin treatment of all remaining animals cured two already sick animals and prevented further cases. A volunteer worker with upper respiratory disease was suspected as source of infection; contact with equine materials and rodents could be excluded.
