Publications by authors named "Ruben Cruz"

2 Publications

  • Page 1 of 1

Evaluation of Antioxidant Capacity of Solanum sessiliflorum (Cubiu) Extract: An In Vitro Assay.

J Nutr Metab 2015 15;2015:364185. Epub 2015 Dec 15.

Programa Multi-Institucional de Pós-Graduação em Biotecnologia, Universidade Federal do Amazonas, 69077-000 Manaus, AM, Brazil.

Cubiu is a vegetable of Solanaceae family, native to the Amazon, which is widely distributed through Brazil, Peru, and Colombia. It is used in food, medicine, and cosmetics by native populations. Research has shown that cubiu extracts have antioxidant activities with great biological relevance. We performed a phytochemical screening to identify the main chemical groups that could confer antioxidant activity to this extract. Several tests and qualitative precipitation specific staining for major classes of secondary metabolites were used. Antioxidant capacity in vitro tests (DPPH and ABTS) were also used to assess the extract's ability to sequester free radicals of 70% hydroethanolic and aqueous extracts of cubiu flour. Alkaloids, organic acids, phenols, flavonoid glycosides, and coumarins were found in the hydroethanolic extract while the aqueous extract presented anthocyanins, gums, tannins and mucilage, amino groups, and volatile and fixed acids. For in vitro tests, the IC50 value obtained in the DPPH assay was 606.3 ± 3.5 μg/mL while that for the ABTS assay was 290.3 ± 10.7 µg/mL. Although cubiu extracts present chemical compounds directly related to antioxidant activity, our results show that it has a low antioxidant activity. Additional studies will be needed to isolate and characterize specific compounds to further assess antioxidant activity.
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http://dx.doi.org/10.1155/2015/364185DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4692998PMC
January 2016

Stability of high temperature chemical vapor deposited silicon based structures on metals for solar conversion.

J Nanosci Nanotechnol 2011 Sep;11(9):8318-22

SIMaP Grenoble INP UJF, CNRS, 38402 Saint Martin d'Hères, France.

Highly crystallized silicon layers were grown on metal sheets at high temperature (950 degrees C) by thermal CVD from silane. An intermediate buffer layer was mandatory to prevent interdiffusion and silicide formation but also to compensate lattice parameters and thermal expansion coefficients mismatches between metal and silicon and ideally transfer some crystalline properties (grain size, texture) from the substrate to the silicon layer. After a thermodynamic study, aluminum nitride or titanium nitride diffusion barrier layers were selected and processed by CVD. The structure and the interfaces stabilities of these silicon/nitride/metal stacks were studied by field effect gun scanning and transmission electron microscopy, X-ray diffraction, Raman and energy dispersive X-ray spectroscopy. As a result, TiN deposited by CVD appears to be an efficient material as a buffer layer between steel and silicon.
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http://dx.doi.org/10.1166/jnn.2011.5077DOI Listing
September 2011