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Search Results: 1 - 10 of 332500 matches for " Emery Flávio S. "
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Trypanocidal activity of isolated naphthoquinones from Tabebuia and some heterocyclic derivatives: a review from an interdisciplinary study
De Moura Kelly C. G.,Emery Flávio S.,Neves-Pinto Cleverson,Pinto Maria do Carmo F. R.
Journal of the Brazilian Chemical Society , 2001,
Abstract: Naphthoquinones isolated from the wood of trees of the families Bignoniaceae and Verbenaceae have been subjected to an interdisciplinary study since the seventies, when Dr. Benjamin Gilbert, at the Federal University of Rio de Janeiro, launched a program on the chemistry of natural products active against endemic diseases. In this paper we describe the synthesis of five naphthoimidazoles, derived from this program and their activity towards T. cruzi, the etiologic agent of Chagas disease. We also review the influence of chemical structure on trypanocidal action of naphthoquinones and of derived heterocycles with imidazole, oxazole, phenoxazine, indole, dipyrane and cyclopentene rings. The overall analysis corroborates the tendency of trypanocidal activity in compounds with an imidazole or oxazole ring linked to a naphthopyrane structure. Two naphthoimidazoles presented higher activities (14.5x and 34.8x) than the standard crystal violet. Emphasis is given to the biodiversity of the Brazilian flora as a starting point for the development of an autonomous and creative medicinal chemistry.
Chemoselective oxidation of benzophenazines by m-CPBA: n-oxidation vs. oxidative cleavage
Silva, Raphael S. F.;Amorim, Mauro B. de;Pinto, Maria do Carmo F. R.;Emery, Flávio S.;Goulart, Marília O. F.;Pinto, Antonio V.;
Journal of the Brazilian Chemical Society , 2007, DOI: 10.1590/S0103-50532007000400014
Abstract: chemoselectivity is observed when a pyran-benzo[a]phenazine and a furan-benzo[a]phenazine from b-lapachone and nor-b-lapachone, respectively, were submitted to oxidation by m-cpba. the pyran phenazine furnished mainly macrolactones, while the furan one led exclusively to a phenazine n-8 oxide. to understand this difference in reactivity, we synthesized a new furan phenazine, with the reactive double bond site less hindered than that of the derivative from nor-beta-lapachone. this furan phenazine, upon oxidation with m-cpba, furnished mainly the expected macrolactone. these experimental results, along with preliminary analysis based on mechanical molecular calculations of the ground state of the substrates, allowed us to suggest that the observed chemoselectivity has a steric oxidant approach control origin, related to the presence of the geminal methyl groups in the phenazine structure. several of the synthesized compounds are, herein, reported for the first time.
Trypanocidal activity of isolated naphthoquinones from Tabebuia and some heterocyclic derivatives: a review from an interdisciplinary study
De Moura, Kelly C. G.;Emery, Flávio S.;Neves-Pinto, Cleverson;Pinto, Maria do Carmo F. R.;Dantas, Andrea P.;Salom?o, Kelly;Castro, Solange L. de;Pinto, Ant?nio V.;
Journal of the Brazilian Chemical Society , 2001, DOI: 10.1590/S0103-50532001000300003
Abstract: naphthoquinones isolated from the wood of trees of the families bignoniaceae and verbenaceae have been subjected to an interdisciplinary study since the seventies, when dr. benjamin gilbert, at the federal university of rio de janeiro, launched a program on the chemistry of natural products active against endemic diseases. in this paper we describe the synthesis of five naphthoimidazoles, derived from this program and their activity towards t. cruzi, the etiologic agent of chagas disease. we also review the influence of chemical structure on trypanocidal action of naphthoquinones and of derived heterocycles with imidazole, oxazole, phenoxazine, indole, dipyrane and cyclopentene rings. the overall analysis corroborates the tendency of trypanocidal activity in compounds with an imidazole or oxazole ring linked to a naphthopyrane structure. two naphthoimidazoles presented higher activities (14.5x and 34.8x) than the standard crystal violet. emphasis is given to the biodiversity of the brazilian flora as a starting point for the development of an autonomous and creative medicinal chemistry.
The Mathematics in the Social Studies Textbook: A Critical Content Analysis and Implications for Students’ Reasoning  [PDF]
Flávio S. Azevedo, Michele J. Mann
Creative Education (CE) , 2019, DOI: 10.4236/ce.2019.101001
Abstract: We report on a case study of the?mathematical?content of a 10th?grade?social studies?textbook. We develop our case in three analytical steps. First, we identify, describe, and categorize the full range of mathematics in the book. Put simply, we ask: What mathematical forms (e.g., Cartesian graphs and problems) do we find and what kinds of mathematical work do they require? Second, we characterize and critically evaluate the mathematics content in the textbook, focusing in particular on the kinds of mathematics literacy and student reasoning that the book fosters. Third and finally, we operationalize a measure of the “density” of mathematics in the textbook—that is, an estimate of the presence and pervasiveness of mathematical objects and practices relative to other disciplinary contentsand track how such “density” has changed over the past three editions of the same volume. Doing so helps us further contextualize and elaborate the prior analyses, but also surfaces shifts in the patterns of mathematics presence in that textbook series, including the growing encroachment of mathematics exercising and visual/representational presence.
1,4- Addition of diazomethane to a heterodiene: a direct preparation of the oxazolic ring
Emery, Flávio da S.;Silva, Raphael S.F.;Moura, Kelly C.G. de;Pinto, Maria C.F.R.;Amorim, Mauro B.;Malta, Valéria R.S.;Santos, Regina H.A.;Honório, Kátia M.;Silva, Albérico B.F. da;Pinto, Antonio V.;
Anais da Academia Brasileira de Ciências , 2007, DOI: 10.1590/S0001-37652007000100004
Abstract: the reaction of naphthoquinone-oximes (3) and (4) with diazomethane yields directly, in one step, the oxazoles (5) and (6), respectively.
Curating Knowledge and Curating Fun: An Analysis of the Expanding Roles of Children’s Museums  [PDF]
Sarah C. Harris, Flávio S. Azevedo, Anthony J. Petrosino
Creative Education (CE) , 2018, DOI: 10.4236/ce.2018.912138
Abstract: Museums constantly undergo shifts and changes in the roles and functions they serve in society. We report on the expanding roles of a children’s STEAM museum through a case study of two adult-only, fundraising events that the museum implemented. Drawing on both qualitative and quantitative measures, our analysis pursues two complementary threads. First, we seek to characterize those events in detail so that we might understand the events’ culture and functioning. Second, we look into the population who frequents the events, focusing specifically on various indicators of socio-economic status. By bringing these analytical threads together, we corroborate the finding that museums are expanding into?curating fun?experiences that are highly tailored to certain segments of the adult public. Importantly, attending to the empirical details of such processes, we further find that the observed changes1) directly impact the job demands and require?skills of children’s museum staff, 2) reify?the museum as an important economic agent in the community, and 3) potentially reproduce patterns of inequitable access to STEAM cultural capital, among others.
Dora, uma experiência dialética
Couto, Luis Flávio S.;
ágora: Estudos em Teoria Psicanalítica , 2004, DOI: 10.1590/S1516-14982004000200006
Abstract: based on the work intervention on transference (lacan, 1951/1998), this essay discusses a lacanian approach to dora's treatment as a dialectical experience. although hegel's conceptions have been surpassed, it is still worth reflecting on the treatment approach that he used in his first practice, in the light of several levels of truth scansions.
Poliniza??o controlada em Araucaria angustifolia
Anselmini, Justina Inês;Zanette, Flávio;
CERNE , 2012, DOI: 10.1590/S0104-77602012000200009
Abstract: the objective of this study was to develop a methodology for controlled pollination of araucaria angustifolia, aiming at the genetic improvement of the species and increased yield of pine nuts through management with supplemental pollination. a methodology of controlled pollination was developed in which several experiments were carried out in 2003-2005 period. the effects of the following parameters were evaluated: controlled pollination, amount of pollen applied per female strobilus, time of pollination, and development stage of the female strobilus during pollination on the number of pine nuts yielded per pine cone. a single controlled pollination procedure results in low yield of fully filled pine nuts, and pollination at later development stages of the female strobilus results in high yields of fully filled pine nuts per pine cone. controlled pollination in a. angustifolia proved effective for pine nut production and its application in oriented breeding procedures will enable breeding that up until now was considered impossible in nature on account of the considerable distance between the parent plants. controlled pollination performed twice in female strobili more than 30 mm in diameter does increase the yield of pine nuts per pine cone.
Projeto econ?mico de cartas adaptativas para monitoramento de processos
Michel, Renato;Fogliatto, Flávio S.;
Gest?o & Produ??o , 2002, DOI: 10.1590/S0104-530X2002000100003
Abstract: statistical control charts have been widely and successfully used for monitoring the performance of industrial processes. several modifications on the classic shewhart charts have been proposed in the literature; they aim at providing better tools for monitoring processes with special characteristics. one such modification is the recently developed adaptive control charts. although providing advantages over shewhart charts, in particular by signaling out-of-control situations faster, there is no prolific literature on practical implementation of adaptive charts. in this article we propose an economic model for the design of adaptive control charts. we apply the model in a case study from the automotive parts industry, detailing the meaning and determination of model parameters. adaptive and shewhart control schemes are compared based on their control costs.
Development and growth curve of the pine cones of Araucaria angustifolia (Bert.) O. Ktze, in the region of Curitiba - PR
Anselmini, Justina Inês;Zanette, Flávio;
Brazilian Archives of Biology and Technology , 2008, DOI: 10.1590/S1516-89132008000400003
Abstract: the objectives of this work were to describe the development and growth rate of the pine cones of araucaria angustifolia during and after the pollination period, to identify the period of maximum growth of the cones and the period of pollination and maturation of the pine nuts. the adult individuals were found at the setor de ciencias agrarias of the ufpr, in curitiba - pr. collections and measurements of pine cones were made in 2003 and 2005. the diameter and the length of the pine cones were measured 15 different times in both the years. in the studied environmental conditions, the period between the pollination and maturation of the pine nuts was 20 months. the maximum pine cone growth was achieved between october and january after the pollination, and between october and april of the following year.
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