M. A. Macêdo

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Received: 11 January 2007 | Accepted: 2 March 2007 | Published: 10 January 2008 Copyright: This is an open access paper. We use the Creative Commons Attribution 3.0 license that permits unrestricted use, provided that the paper is properly attributed. ISSN: 1536-2442 | Volume 8, Number 4 Cite this paper as: Stansly PA, McKenzie CL. 2007. Fourth(More)
The activity of phenethyl alcohol (PEA) on Bacillus cereus, B. megaterium, and Streptococcus faecalis was studied by electron microscopy of thin sections and by the assay of intracellular K+ leakage. S. faecalis was unaffected by PEA at concentrations up to 0.5%, B. cereus was severely damaged by 0.5% PEA, and B. megaterium behaved intermediately. Important(More)
The ultrastructural study of membrane organization in gram-positive bacteria related to the OSO4 fixation conditions revealed that large, complex mesosomes are observed only when the bacteria are subjected to an initial fixation with 0.1%OSO4 in the culture broth, as in the prefixation step of the Ryter-Kellenberger procedure. Evidence was obtained(More)
In this communication we present a new sol–gel route to obtain high quality BaFe12O19 thin films. X-ray analysis confirmed the crystal structure with a crystal size of 32 nm. Atomic force microscopy images determined the film thickness to be around 250 nm and a roughness factor of less than 40 nm where the grain size averaged around 150 nm. SQUID(More)
In some epidemics that have devastating consequences, the primary inoculum plays an important role in both epidemic onset and intensification. This article documents the dynamics of such epidemics, and illustrates their importance using two examples: Huanglongbing of citrus and begomoviruses of tomato. The latter disease is a major constraint to tomato(More)
We report on the synthesis of nickel nanoparticles using a combination of chemical reduction and freezing-drying processes that we named the aquolif approach. The X-ray diffraction (XRD) patterns reveal that the synthesized nanoparticles were composed of a single metallic nickel phase. The average crystallite sizes of the nickel nanoparticles were(More)
In this work, silver atoms were deposited by ion sputtering on the surface of diglycidyl ether of bisphenol A (DGEBA) epoxy resin cured at 150 °C for 6 hours in air. The films of DGEBA and its precursors were characterized by Raman spectroscopy to identify the main functional groups and their relationship with the deposited silver atoms. Silver thin films(More)