Publications by authors named "R A Ikeoka"

This article presents the first results for elemental composition of 193 fragments ceramic from four sites located in Ventarrón-Collud archaeological complex, Peru. The results from EDXRF and multivariate analysis indicated statistical similarity among four groups of ceramic fragments, selected by remarkable stylistic variation, collected from different archaeological space/time contexts. The correspondence in the elemental composition of the ceramic paste of the artifacts corroborates the hypothesis that similar raw materials were used consistently throughout the entire occupation of this archaeological complex.

View Article and Find Full Text PDF

This study refers to the archaeometric analysis of ceramic fragments found in archaeological excavations around slave quarters of Colégio dos Jesuítas and São Bento plantations, both located in Campos dos Goytacazes - RJ. The question whether handmade ceramics were produced by the slaves themselves or acquired through local trade networks is an open and important question in the African diaspora. Samples of clay sources and the ceramic fragments, were analyzed using the EDXRF technique with the aid of multivariate statistical analysis.

View Article and Find Full Text PDF

Four (99m)Tc-labeled chalcone derivatives and their corresponding rhenium analogues were tested as potential probes for imaging β-amyloid plaques. The chalcones showed higher affinity for Aβ(1-42) aggregates than did (99m)Tc complexes. In sections of brain tissue from an animal model of AD, the four Re chalcones intensely stained β-amyloid plaques.

View Article and Find Full Text PDF

Two (99m)Tc/Re complexes based on flavone and aurone were tested as potential probes for imaging β-amyloid plaques using single photon emission computed tomography. Both (99m)Tc-labeled derivatives showed higher affinity for Aβ(1-42) aggregates than did (99m)Tc-BAT. In sections of brain tissue from an animal model of AD, the Re-flavone derivative 9 and Re-aurone derivative 19 intensely stained β-amyloid plaques.

View Article and Find Full Text PDF

This paper describes the synthesis and biological evaluation of a new series of 2,5-diphenyl-1,3,4-oxadiazole (1,3,4-DPOD) derivatives for detecting beta-amyloid plaques in Alzheimer's brains. The affinity for beta-amyloid plaques was assessed by an in vitro binding assay using pre-formed synthetic Abeta42 aggregates. The new series of 1,3,4-DPOD derivatives showed affinity for Abeta42 aggregates with K(i) values ranging from 20 to 349 nM.

View Article and Find Full Text PDF