Hybrid pigments resulting from several guest dyes onto γ-alumina host: A spectroscopic analysis.

The synthesis of hybrid pigments was made from combination of γ-AlO and some organic chromophores such as carminic acid, alizarin, purpurin, curcumin, fluorescein and betacyanins. The γ-AlO was obtained through sol-gel synthesis with 2-propanol and aluminium tri-sec-butoxide (ATB). This article presents some spectroscopic evidences related to the formation of aluminium complexes between coordinative unsaturated sites (CUS) of aluminium and some organic groups (carboxylic acid, quaternary ammonium and β-keto enol) present in the chromophores structure.

Electrophysiological Studies of Face Perception in Humans.

Event-related potentials (ERPs) associated with face perception were recorded with scalp electrodes from normal volunteers. Subjects performed a visual target detection task in which they mentally counted the number of occurrences of pictorial stimuli from a designated category such us butterflies. In separate experiments, target stimuli were embedded within a series of other stimuli including unfamiliar human faces and isolated face components, inverted faces, distorted faces, animal faces, and other nonface stimuli.