Estudio del comportamiento ante la corrosión de películas delgadas de Ni y óxiido de Ni obtenidas por espurreo catódico frente a un medio amargo

En este trabajo se presenta el estudio del comportamiento de películas delgadas de níquel y un óxido superior de níquel obtenidas por espurreo catódico sobre acero AISI 1018 (UNS G 10180), con el propósito de disminuir la velocidad de corrosión del acero al carbono cuando se expone a un medio amargo (presencia de ácido sulfhídrico y cloruros) y alargar la vida útil de las estructuras petroquímicas metálicas, con lo que se ahorraría una importante cantidad de recursos monetarios y humanos. La caracterización de las superficies se realizó utilizando las técnicas electroquímicas[1] (curvas de polarización y espectroscopia de impedancia electroquímica)

Antibacterial and Antibiofilm Activities of the Photothermal Therapy Using Gold Nanorods against Seven Different Bacterial Strains

The objective of this work was to determine the bactericidal and antibiofilm activities of gold nanorods (AuNRs) using plasmonic photothermal therapy (PPTT) against oral microorganisms. AuNRs were synthesized by the seed and growth solution method and the gold nanoclusters were characterized with a size of 33.2 nm ± 2.23 length and 7.33 nm ± 1.60 width. The efficacy of PPTT related to its temperature was done reaching 67°C. Minimum inhibitory concentration (MIC) and minimum bactericide concentration (MBC) of AuNRs and AuNRs PPTT were determined against Enterococcus faecalis, Staphylococcus aureus, Streptococcus mutans, Streptococcus sobrinus, Streptococcus oralis, Streptococcus salivarius, and Escherichia coli growth. The antibiofilm activity of AuNRs was explored by fluorescence microscopy. After experimental analyses, AuNRs PPTT shows better results in MICs and MBCs, when it was compared with AuNRs alone. The laser employed to activate the AuNRs had no antibacterial effect against oral microbes. The MICs and MBCs values were higher for S. aureus and E. coli and lower against S. oralis. Surprisingly, the AuNRs alone presented a high antibiofilm activity, inhibiting the biofilm formation of S. mutans. Altogether, these results strongly suggest that AuNRs could be an interesting option to control oral biofilms