Author
Antonio G. Ferreira
Other affiliations: Centro Hospitalar de Vila Nova de Gaia/Espinho, University of Coimbra, Federal University of Rio de Janeiro ...read more
Bio: Antonio G. Ferreira is an academic researcher from Federal University of São Carlos. The author has contributed to research in topics: Medicine & Porphyrin. The author has an hindex of 34, co-authored 313 publications receiving 4689 citations. Previous affiliations of Antonio G. Ferreira include Centro Hospitalar de Vila Nova de Gaia/Espinho & University of Coimbra.
Papers published on a yearly basis
Papers
More filters
TL;DR: A review on analytical methods used to evaluate biodiesel quality was written by Knothe as discussed by the authors, and a review of the available techniques and some improvements on the analytical methods for biodiesel characterization can be found in this paper.
293 citations
TL;DR: The efficiency of microwave-assisted acid digestion of plants using different concentrations of nitric acid with hydrogen peroxide (30% v/v) was evaluated by measuring the residual carbon content (RCC) using inductively coupled plasma optical emission spectrometry (ICP-OES) with axial viewing as mentioned in this paper.
165 citations
TL;DR: The methodology was successfully applied to determine the fatty acid composition of several edible oils, with equivalent results to those given by the AOAC Official method by gas chromatography.
Abstract: A simple methodology for the determination of the fatty acid composition of edible oils through (1)H NMR is proposed. The method is based on the fact that all fatty acid chains are esterified to a common moiety, glycerol, and the quantification is done directly in the (1)H NMR spectra through the relationship between the areas of a characteristic signal of each fatty acid and a signal of the glycerol moiety, without the use of mathematical equations. The methodology was successfully applied to determine the fatty acid composition of several edible oils, with equivalent results to those given by the AOAC Official method by gas chromatography. Its main advantages are simplicity and the lack of need for sample pre-treatment such as derivatization or extraction.
165 citations
TL;DR: Bioassay-guided fractionation of the bark extract of Annona foetida afforded a new antileishmanial pyrimidine-beta-carboline alkaloid, N-hydroxyannomontine, which is particularly important for Annona genus chemotaxonomy.
Abstract: Bioassay-guided fractionation of the bark extract of Annona foetida afforded a new antileishmanial pyrimidine-beta-carboline alkaloid, N-hydroxyannomontine (1), together with the previously reported annomontine (2), O-methylmoschatoline (3), and liriodenine (4). The structure of compound 1 was established on the basis of extensive 1D and 2D NMR and MS analyses. This is the third reported pyrimidine-beta-carboline-type alkaloid and is particularly important for Annona genus chemotaxonomy. In addition, all compounds exhibit in vitro antileishmanial activity against promastigote forms of Leishmania braziliensis. Compounds 2 and 4 showed better activity than compounds 1 and 3 against L. braziliensis. Compound 2 was not active against L. guyanensis.
154 citations
TL;DR: In this article, the use of 1 H NMR to quantify different methyl biodiesels in diesel from different sources is described, and some relationships of integrals are employed to construct calibration curves.
131 citations
Cited by
More filters
TL;DR: This review covers the literature published in 2014 for marine natural products, with 1116 citations referring to compounds isolated from marine microorganisms and phytoplankton, green, brown and red algae, sponges, cnidarians, bryozoans, molluscs, tunicates, echinoderms, mangroves and other intertidal plants and microorganisms.
4,649 citations
01 Jan 2008
TL;DR: In this article, the authors argue that rational actors make their organizations increasingly similar as they try to change them, and describe three isomorphic processes-coercive, mimetic, and normative.
Abstract: What makes organizations so similar? We contend that the engine of rationalization and bureaucratization has moved from the competitive marketplace to the state and the professions. Once a set of organizations emerges as a field, a paradox arises: rational actors make their organizations increasingly similar as they try to change them. We describe three isomorphic processes-coercive, mimetic, and normative—leading to this outcome. We then specify hypotheses about the impact of resource centralization and dependency, goal ambiguity and technical uncertainty, and professionalization and structuration on isomorphic change. Finally, we suggest implications for theories of organizations and social change.
2,134 citations
TL;DR: In this paper, the fatty acid (FA) profiles of 12 common biodiesel feedstocks were summarized, and it was shown that several fuel properties, including viscosity, specific gravity, cetane number, iodine value, and low temperature performance metrics are highly correlated with the average unsaturation of the FA profiles.
Abstract: Biodiesel is a renewable transportation fuel consisting of fatty acid methyl esters (FAME), generally produced by transesterification of vegetable oils and animal fats. In this review, the fatty acid (FA) profiles of 12 common biodiesel feedstocks were summarized. Considerable compositional variability exists across the range of feedstocks. For example, coconut, palm and tallow contain high amounts of saturated FA; while corn, rapeseed, safflower, soy, and sunflower are dominated by unsaturated FA. Much less information is available regarding the FA profiles of algal lipids that could serve as biodiesel feedstocks. However, some algal species contain considerably higher levels of poly-unsaturated FA than is typically found in vegetable oils. Differences in chemical and physical properties among biodiesel fuels can be explained largely by the fuels’ FA profiles. Two features that are especially influential are the size distribution and the degree of unsaturation within the FA structures. For the 12 biodiesel types reviewed here, it was shown that several fuel properties – including viscosity, specific gravity, cetane number, iodine value, and low temperature performance metrics – are highly correlated with the average unsaturation of the FAME profiles. Due to opposing effects of certain FAME structural features, it is not possible to define a single composition that is optimum with respect to all important fuel properties. However, to ensure satisfactory in-use performance with respect to low temperature operability and oxidative stability, biodiesel should contain relatively low concentrations of both long-chain saturated FAME and poly-unsaturated FAME.
1,527 citations
TL;DR: High mechanical strength in wet state, enormous water retention values, low roughness of the inner surface, and a complete ‘vitalization’ of BASYC ® — microvessel-interpositions in rat experiments demonstrate the high potential of BasyC ® as an artificial blood vessel in microsurgery.
1,178 citations
TL;DR: This 11th edition of the book Modern Nutrition in Health and Disease, featuring the work of more than 190 expert authors and divided into five parts, fully explains and encapsulates the fundamentals of nutrition and its role in contemporary society.
Abstract: This 11th edition of the book Modern Nutrition in Health and Disease, featuring the work of more than 190 expert authors and divided into five parts, fully explains and encapsulates the fundamentals of nutrition and its role in contemporary society, from mastering the basic science of nutrient metabolism and function to applying nutritional concepts to combat human disease. Part I comprehensively covers specific dietary components, including major dietary constituents, minerals, vitamins and other Other CABI sites
1,105 citations