Navegando por Título

Agora exibindo 1 - 20 de 16194

10 km running race induces an elevation in the plasma myokine level of nonprofessional runners.
(2019) Barbosa, Lucas Soares Marcucci; Martins Junior, Francisco de Assis Dias; Lobo, Lázaro Fernandes; Morais, Mariana Gomes de; Moreira, Janaina Matos; Vieira, Érica Leandro Marciano; Silva, Albená Nunes
Purpose Acute and chronic physical exercise is believed to have benefcial efects on human health. Exercise is also able to modulate immune function. We hypothesed that exercise is able to induce many benefts for human health by modulating immune functions through the production and release of many myokines. Here, we investigated the efects of a running race on the level of plasmatic myokines. Methods Nine male volunteers took part in this study. Blood samples were obtained before, immediately after and 24 h after the race. Results Participants completed the 10 km running race in 49.85±7.04 min. The levels of IL-6 elevated after exercise (0.94±0.4–2.82±0.3 pg/ml). The IL-15 plasma level was also higher immediately after (0.88±0.25–1.29±0.36 pg/ml), and 24 h after (1.30±1.01 pg/ml), the end of the exercise. Irisin increased only 24 h after exercise (632.60±188.40– 974.70±232.30 pg/ml). FABP3 increased after exercise (829.60±68.93–1306.00±319.10 pg/ml). The plasma levels of BDNF (4719.00±701.80–5557.00±810.30 pg/ml) and Fractalkine increased after exercise (101.2±34.96–134.90±43.62 pg/ ml). The level of FSTL (7265.00±1553.00–9074.00±1662.00 pg/ml) and Osteonectin (16.52±3.54–15.71±3.38 pg/ml) also increased after exercise, and then returned to baseline level 24 h after the end of the session. Conclusion Taken together, these results suggest that a 10 km running race induces elevation of important myokine plasma levels.
[10]obediência cênica.
(2017) Caiafa, Frederico Alves; Oliveira, Aline Mendes de; Oliveira, Aline Mendes de; Amaral, Maria Elisa Martins Campos do; Dias, Luciana da Costa
A [10]obediência Cênica é a impossibilidade de seguir regras estéticas para se realizar qualquer atividade artística, no âmbito da presença e em espaço urbano. Nesse sentido, a intenção é tratar a arte desta cena como não pertencente à área alguma. Cunhei o termo a partir da transgressão gráfica e por miscigenar significantes de naturezas diversas na produção de uma nova escrita para o título. Por intermédio de um exercício ético, estético e político, elenca-se pontos de semelhança em cada capítulo a fim rascunhar uma “cartografia analítica”, um rizoma de afecção performática, sintonizada às ideias ao redor da origem transgressora que nomeia esta pesquisa. Até o encontro com este modus operatio de trabalho e de vida que faz uso de aportes de campos diversos e contíguos às artes cênicas – filosofia, política, etc. – para criar a superfície de observação da produção desta escrita e consequente análise dos trabalhos escolhidos. Ao afeiçoarmo-nos por ações artísticas e de intervenção, criações que se associam a uma arte e a um certo ativismo, ou mesmo o inventado termo artivismo, enquanto outras atuam por frentes diretas, como no caso do terrorismo poético e do escrache. Assim, unem-se diversas linguagens que estão na mesma posição enquanto postura civil por se confrontarem com limites impostos à sua liberdade criativa. Arte vândala que se intenciona a dar outra forma, movediça, ao que se estabelece no cotidiano da tela urbana propondo a desobediência como resposta às “leis injustas”.
Um 13 de maio antecipado : edições temáticas, atualidade e memória no circuito TRIP e TPM.
(2016) Tavares, Frederico de Mello Brandão
Em abril de 2014, as revistas brasileiras TRIP e TPM publicaram uma edição temática, sob o mesmo título base – “Ser negro/negra no Brasil é f*da”, e estabeleceram um diálogo editorial a partir de um gancho temporal: o dia 13 de maio, quando se comemora a abolição da escravatura no país. Com um mês de antecedência e a partir de coberturas estruturadas por conteúdos específicos, em contato ou não, as publicações anteciparam o acontecimento, previsto, encerrando-o em uma “totalidade” de pautas, acionada por seções e provocadora de um circuito que, antes do “acontecer do acontecimento”, atualizou-o como temática, indicando seus sentidos. Neste contexto, o presente artigo observa relações existentes em acionamentos acontecimentais no jornalismo, mesmo quando estes não partem de uma cobertura factual. Tendo como objeto as edições de TRIP e TPM indicadas, busca-se percorrer a transversalidade originada pela tematização das revistas e compreender as afetações e/ou “determinações” que nela aparecem.
1492 : partos do fecundo oceano - relatos históricos sobre o descobrimento da América em dois tempos (as Décadas de Anglería e de Herrera).
(2014) Reis, Anderson Roberti dos; Fernandes, Luiz Estevam de Oliveira
O artigo busca analisar as concepções de tempo e de escrita da história em dois cronistas, Pedro Mártir de Anglería e Antonio de Herrera y Tordesillas, ambos narradores dos eventos de 1492 em forma de “Décadas”. O primeiro escrevendo no calor dos acontecimentos, na virada do XV para o XVI, e o segundo, no início do século XVII. Para atingir tais objetivos, buscamos uma contextualização de suas produções e procuramos verificar como suas concepções de história e de narrativa ligavam-se a preceitos políticos e providenciais. Além disso, realizamos uma discussão sobre o próprio conceito de crônica e seus modos de registrar a história espanhola como um fenômeno atlântico ao longo do século XVI, mostrando o modo pelo qual as fórmulas de Anglería e de Herrera relacionavam-se com a tradição e a modernidade.
15 anos de extensão na engenharia de minas.
(2016) Walter, Guilherme; Gloss, Crislayne; Nogueira, Francielle Câmara; Pereira, Carlos Alberto
O primeiro projeto de extensão do Departamento de Engenharia de Minas, Oficina de Cantaria, da Universidade Federal de Ouro Preto (UFOP) procurou valorizar o ser humano, aproximar a comunidade da Universidade, integrar os saberes. Essas atividades vieram integrar o que ficou destacado no último Plano Nacional de Educação 2011-2020 que chama a atenção para as universidades sobre o papel da extensão. A arte de cantaria foi trazida para o Departamento de Engenharia de Minas (Demin) por meio das mãos do mestre José Raimundo Pereira, o Seu Juca, uns dos últimos oficiais canteiros do Estado de Minas Gerais. O projeto completou 15 anos em 2015. Ao longo desses anos, buscou a formação dos graduandos, a integração da comunidade com a UFOP, a pesquisa histórica e de materiais, a formação de novos trabalhadores habilitados e a preservação do patrimônio direcionada para os trabalhos com as metodologias da educação patrimonial. Nesse período, foram restauradas pontes, chafarizes, cruz, a Estação de Ferro de Itabirito. Foram produzidas, na oficina e nas aulas para formação de canteiros, noventa e seis peças de quartzito, dezesseis peças de canga. Soma-se aos resultados a formação de onze canteiros, 23 alunos de história, 33 trabalhos de iniciação científica e 88 de extensão. O número de publicações foi significativo: um livro, três artigos em periódicos, oito capítulos de livro, sessenta e sete artigos publicados em congressos nacionais e internacionais. A divulgação da arte foi feita também por meio de exposições permanentes no Museu de Ciência e Técnica da Escola de Minas, e itinerantes no Palácio das Artes.
1D and 2D Fourier-based approaches to numeric curvature estimation and their comparative performance assessment.
(2003) Estrozi, Leandro Farias; Rios Filho, Luiz Gonzaga; Bianchi, Andrea Gomes Campos; César Júnior, Roberto Marcondes; Costa, Luciano da Fontoura
A careful comparison of three numeric techniques for estimation of the curvature along spatially quantized contours is reported. Two of the considered techniques are based on the Fourier transform (operating over 1D and 2D signals) and Gaussian regularization required to attenuate the spatial quantization noise. While the 1D approach has been reported before and used in a series of applications, the 2D Fourier transform-based method is reported in this article for the first time. The third approach, based on splines, represents a more traditional alternative. Three classes of parametric curves are investigated: analytical, B-splines, and synthesized in the Fourier domain. Four quantization schemes are considered: grid intersect quantization, square box quantization, a table scanner, and a video camera. The performances of the methods are evaluated in terms of their execution speed, curvature error, and sensitivity to the involved parameters. The third approach resulted the fastest, but implied larger errors; the Fourier methods allowed higher accuracy and were robust to parameter configurations. The 2D Fourier method provides the curvature values along the whole image, but exhibits interference in some situations. Such results are important not only for characterizing the relative performance of the considered methods, but also for providing practical guidelines for those interested in applying those techniques to real problems.
1D coordination polymer based on copper(II)-containing tetrameric 1,2,3- triazole ligand from click chemistry : magnetic and catalytic properties.
(2019) Teixeira, Leonardo César de Moraes; Souza, Gilmar Pereira de; Fajardo, Humberto Vieira; Luz, Sulusmon Cesar; Álvarez, Eleuterio; Lloret, Francesc; Viana, Renato Márcio Ribeiro; Rojo Marcos, Francisco Javier; Stumpf, Humberto Osório; Figueiredo, Rute Cunha; Correa, Rodrigo de Souza
A novel tetrameric tetra[O-((1-benzyl-1H-1,2,3-triazol-4-yl)methyl)]-pentaerythritol (TBTP) has been synthesized using click chemistry strategy. TBTP was characterized and used as ligand to form new Cu(II) complexes, forming 1-D coordination polymers. Two square planar complexes were characterized by single-crystal X-ray diffraction, presenting formula [Cu(TBTP)][Cu(NO3)4] (1) and [Cu(TBTP)](NO3)2 (2). In both structures, a cationic 1-D coordination polymer (CP) has been formed. The CP contain a 1:1 Cu(II)/TBTP ratio with four neutral triazole groups coordinating the Cu(II) center, forming a CuN bonds ranging 1.988(2)–2.001(2) Å. The study of the magnetic properties of compounds 1 and 2 pointed to an antiferromagnetic behavior for both compounds, defined by inter- and intra-chain dipolar interactions among their metallic centers. In addition, the complex 1 was found to be an efficient catalyst for selective oxidation of aniline to azobenzene under mild reaction conditions.
2 Hydroxy-1,4-naphthoquinone (Lawsone) as a redox catalyst for the improvement of the alkaline pretreatment of sugarcane bagasse.
(2021) Barreto, Elisa da Silva; Baeta, Bruno Eduardo Lobo; Pereira, Márcio César; Pasquini, Daniel; Guimarães, Valéria dos Santos; Gurgel, Leandro Vinícius Alves
This study evaluated the use of a new redox catalyst (2-hydroxy-1,4-naphthoquinone, HNQ) in order to contribute to the preservation of the carbohydrate fraction and to increase delignification of sugarcane bagasse (SB) subjected to soda pretreatment, without inhibiting enzyme activity during saccharification. The effects of HNQ were compared to the well-known redox catalyst anthraquinone (AQ). A 25 1 fractional design and a 22 central composite design were used for optimization of the soda-HNQ pretreatment of SB. The use of HNQ promoted preservation of 76.4% cellulose and 86.2% hemicelluloses, as well as 86.1% delignification of raw SB, showing a superior performance than AQ. The optimized pretreatment conditions were 150 °C, 60 min, 15% (w w−1 ) NaOH, 0.4% (w w−1 ) HNQ, and a liquid-to-solid ratio of 9.6 mL g−1 . Saccharification of SB pretreated by soda HNQ yielded higher overall glucose (74.0%) and xylose (74.3%) yields compared to SB pretreated by AQ (64.9% glucose, 67.3% xylose).
2,2’,4-Trihydroxybenzophenone : crystal structure, and anti-inflammatory and antioxidant activities.
(2007) Doriguetto, Antônio Carlos; Martins, Felipe Terra; Ellena, Javier Alcides; Salloum, Rogério; Santos, Marcelo Henrique dos; Moreira, Maria Eliza de Castro; Silva, Jose Mauricio Schneedorf Ferreira da; Nagem, Tanus Jorge
The crystal structure of C 2,2’,4-trihydroxybenzophenoneD (¼(2,4-dihydroxyphenyl)(2-hydroxyphenyl) methanone; 1) was determined, and its molecular structure, along with intra- and intermolecular Hbonds, was analyzed. The anti-inflammatory potential of 1, evaluated by means of the rat-paw-edema assay, with carrageenan as inflammation stimulus, was found to be similar high as that of indomethacin. In contrast, benzophenone proper (2) was hardly active in this assay. Our results indicate that these antiinflammatory effects are related to the action of kinins and prostaglandins. The radical-scavenging properties of 1 towards DPPH were found to be similar as those of typical phenolics, but somewhat lower than that of ascorbic acid. The structure–activity relationship (SAR) of 1 is discussed.
2020, a natureza disse : pare!.
(2021) Kangussu, Imaculada Maria Guimarães
O presente ensaio apresenta, com ajuda de alguns luminares na história da filosofia e de modo bastante sucinto, a situação pandêmica em que o mundo se encontra, neste ano de 2020, e, voltando os olhos para a história pregressa, busca compreender o que nos trouxe a esse momento de agora e como se desenha o futuro. As quatro partes que o compõem mostram os acontecimentos de antes, de muito antes, de agora e, talvez, do futuro da história.
A 2D model of the dynamic of the collision : I 2 -polymeric liquid surfaces of perfluorinatedpolyether (PFPE), polydimetilsiloxane (PDMS) and squalane.
(2007) Leal, Alexandre Soares; Santos, Cláudio Gouvêa dos; Quintella, Cristina Maria Assis Lopes Tavares da Mata Hermida; Schor, Heloiza Helena Ribeiro
Este artigo apresenta um modelo em duas dimensões para o espalhamento de I 2 pela superfície de líquidos poliméricos: poliéterperfluorado (PFPE), polidimentilsiloxano (PDMS) e esqualano. A função energia potencial adotada para descrever a interação do gás com a superfície líquida formulada é do tipo LEPS. Cada molécula diatômica I 2 e o potencial I-superfície são representados como uma função de Morse, com parâmetros ajustados de dados experimentais do espalhamento sobre as referidas superfícies. A superfície líquida foi modelada como um oscilador harmônico bidimensional. Os resultados obtidos com este modelo simplificado da superfície reproduzem, satisfatoriamente, os dados experimentais da dinâmica do espalhamento, em que os processos de espalhamento inelástico e captura e desorção são caraterizados. A temperatura vibracional da molécula de I 2 espalhada foi determinada em concordância com os resultados experimentais.
3'UTR polymorphism of Thymidylate Synthase gene increased the risk of persistence of pre-neoplastic cervical lesions.
(2020) Silva, Nayara Nascimento Toledo; Santos, Ana Carolina da Silva; Nogueira, Verlândia Mendes; Carneiro, Cláudia Martins; Lima, Angélica Alves
Background: Cervical cancer is caused by high-risk Human Papillomavirus (hr-HPV) infection associated with cofactors that has been analyzed as predictors of the remission or persistence of cytological abnormalities remission or persistence. These cofactors can be either environmental, epigenetic, or genetic. Polymorphism in genes of enzymes that act on one-carbon metabolism alter their activity and also may be associated with cervical carcinogenesis because they affect DNA synthesis and repair, and gene expression. Therefore, this study aimed to analyze the risk of persistence of pre-neoplastic cervical lesions according to genetic polymorphisms involved in one-carbon metabolism. Methods: Our sample consisted of 106 women, divided into two groups – Remission (n = 60), i.e., with the presence of pre-neoplastic lesions at first meeting (T1) and normal cytology after 6 months of follow-up (T2), and Persistence (n = 46), i.e., with the presence of pre-neoplastic lesions at T1 and T2. We obtained cervical samples for cytological analysis (T1 and T2), HPV detection (T1), and evaluation of polymorphism C667T of Methylenetetrahydrofolate Reductase (MTHFR C677T), A2756G of Methionine Synthase (MS A2756G), A66G of Methionine Synthase Reductase (MTRR A66G), double or triple 28 bp tandem repeat in 5′-untranslated enhanced region of Thymidylate Synthase (TSER), and 6 bp deletion at nucleotide 1494 in TS 3′-untranslated region (TS3’UTR). To analyze all genetic polymorphisms simultaneously, we calculated the Genetic Risk Score (GRS). Results: We observed no differences between the Remission and Persistence groups regarding the GRS. Also, there were no differences in the genotypic and allelic distribution of MTHFR C677T and MS A2756G polymorphisms. However, the risk of persistence was higher among women with the heterozygote genotype - ins/del [OR (IC95%): 3.22 (1.19–8.69), p = 0.021], or the polymorphic genotype – del/del [OR (IC95%): 6.50 (1.71–24.70), p = 0.006] of TS3’UTR. Conclusions: The presence of the TS3’UTR polymorphism increased the risk of persistence of cervical abnormalities. This genetic variant could be a potential marker of cervical carcinogenesis and therefore assist the follow-up of women with persistent pre-neoplastic cervical lesions.
3+1 e suas (in)variantes : reflexões sobre as possibilidades de uma nova estrutura curricular na licenciatura em matemática.
(2012) Moreira, Plínio Cavalcanti
Uma análise atenta dos currículos da formação inicial do professor de matemática no Brasil nos leva à seguinte conclusão: a licenciatura saiu do 3+1, mas o 3+1 ainda não saiu da licenciatura. No que segue, explico o que quero dizer com isso, defendo a necessidade urgente de uma efetiva superação desse esquema na formação inicial do professor e discuto as possibilidades de implementação de uma nova estrutura nos cursos de licenciatura em matemática. Este texto, escrito para a conferência de encerramento da II Escola de Inverno em Educação Matemática (Santa Maria, RS), não é um relato de pesquisa, mas as ideias aqui desenvolvidas têm seus fundamentos em parte da literatura especializada na área de formação de professores de matemática, principalmente das três últimas décadas. Num momento em que se discutem, nacionalmente, os Referenciais Curriculares para a Formação do Professor (vide Comissão Paritária SBEM-SBM), este texto chama a atenção para as dificuldades estruturais inerentes a uma concepção curricular em que a formação matemática e as discussões de questões referentes aoensino escolar da matemática sejam vistos como blocos de formação relativamente autonomizados.
3-beta-(Stearyloxy)olean-12-ene from Austroplenckia populnea : structure elucidation by 2D-NMR and quantitative 13C-NMR spectroscopy.
(2003) Vieira Filho, Sidney Augusto; Duarte, Lucienir Pains; Silva, Grácia Divina de Fátima; Howarth, O. W.; Lula, Ivana Silva
3 -(Stearyloxy)olean-12-ene was isolated from a hexane extract of Austroplenckia populnea Reiss (Celastraceae) leaves. The structure was solved by means of quantitative 13C-NMR, HMBC, HMQC, COSY, NOESY, and NOE difference spectra. The mass spectrum showed an [M 1] ion peak at m/z 693, and the molecular formula C48H84O2 was confirmed by combustion analysis.
3.30 Ga high-silica intraplate volcanic–plutonic system of the Gavião Block, São Francisco Craton, Brazil : evidence of an intracontinental rift following the creation of insulating continental crust.
(2016) Zincone, Stéfano Albino; Oliveira, Elson Paiva de; Laurent, Oscar; Zhang, Hong; Zhai, Mingguo
High-silica rhyolites having U–Pb zircon ages of 3303±11Ma occur along the eastern border of the Gavião Block (Brazil) associated with the Contendas-Mirante and Mundo Novo supracrustal belts. Unlike many Archean greenstone sequences, they are not interlayered with mafic to intermediate units. Instead, they belong to an inter-related plutonic–volcanic system, together with granitic massifs having similar zircon crystallization ages of ca. 3293 ± 3 Ma and 3328 ± 3 Ma and plotting along the same geochemical trends as the rhyolites. The rhyolites show well-preserved primary volcanic features such as magma flow textures and euhedral phenocrysts. High emplacement temperatures are indicated by petrographic evidence (β-quartz phenocrysts), zircon saturation temperatures (915–820 °C) and geochemical data, especially high SiO2 (74–79 wt.%) togetherwith elevated Fe2O3(T) (~3 wt.%), MgO (0.5–1.5 wt.%) and low Al2O3 (b11 wt.%). The rhyolites show homogeneous trace element ratios (La/YbN 4.8 ± 1.8; EuN/Eu* ~0.55; Sr/Y ~0.7) and negative ԐHf(3.3 Ga) from 0 to −7, indicating derivation from a single crustal source for both occurrences. Specifically, the rhyolites would have derived from extraction and eruption of highly silicic residual liquid formed by crystallization of granitic magma in a relatively shallow (b10 km) reservoir, now represented by the granite massifs. The granite magma was formed by melting or differentiation of material similar to the diorite gneiss that occurs regionally. The 3.30 Ga volcanic– plutonic systems formed after a period of crustal growth and stabilization of a thick continental lithosphere, represented by massive 3.40–3.33 Ga TTG and medium to high-K calk-alkaline magmatism in the Gavião Block. The 3.30 Ga-old rhyolites and graniteswould therefore have formed in an intracontinental tectonic setting after the formation and stabilization of newcontinental crust, and accordinglywould represent the first stages of rifting and continental break-up. Intraplate magmatism and intracrustal differentiation processes took place on Earth at 3.3 Ga and produced magmas that were distinct from Archean TTGs, questioning the reliability (or at least the uniqueness) of “intraplate models” to explain the origin of the latter.
3230-3200 Ma post-orogenic extension and mid-crustal magmatism along the southeastern margin of the Barberton Greenstone Belt, South Africa.
(2011) Lana, Cristiano de Carvalho; Buick, Ian S.; Stevens, Gary; Rossouw, Riana; Wet, Willem de
The Barberton Granitoid-Greenstone Terrain (SouthAfrica) preserves a complex and protracted evolution involving several events of magmatism and terrain accretion along convergent tectonic boundaries. Recent studies propose that the main period of tectonic accretion and arc-related magmatism is linked to a system of divergent subduction zones above which voluminous TTG magmas were emplaced between ca. 3236 and 3227 Ma. Our structural and LA-ICP-MS U–Pb geochronology study along the southeasternmargin of the BarbertonGreenstoneBelt (BGB) ties the waning stages of this TTG magmatism to a short (ca. <30 Ma) period of mid-crustalextension, between 3228 and 3205 Ma. We document a major NE-trending detachment that juxtaposed upper sequences (Moodies Group clastic sediments) against mid-crustal 3418 ± 10 Ma amphibolite-facies rocks of the base of the greenstonebelt (Onverwacht Group rocks). Several granodiorite bodies - intruded along this detachment - contain well-preserved (syn- and post-magmatic) fabrics that are demonstrably related to extensional shearing and exhumation. Field observations and U–Pb zircon data from these granitoids are consistent with the deformation taking place at 3228 ± 10 Ma – contemporaneous with the voluminous (3236–3227 Ma) TTG magmatism in the northwestern margin of the BGB. The timing of the granodiorite emplacement also constrains a minimum age for the deposition of the Moodies Group clastic sediments, which for much of the southern and southeastern parts of the BGB must have happened before ca. 3228 Ma. 3205 ± 9 Ma subvolcanic dykes intruded into the granodiorite complex indicate that the period of exhumation and cooling of the crystalline rocks along the extensional detachment was relatively short (<30 Ma), between 3228 and 3205 Ma. Our observations combined with previously published structural data from the northwestern and southern margin of the belt suggest that the main mechanism of large-scale infolding of the supracrustal strata was shortly followed by the extension-related magmatism and subsequent, solid-state diapiric movement of the arc-related plutons.
57Fe Mössbauer effect study of Al-substituted lepidocrocites.
(1996) Grave, Eddy De; Costa, Geraldo Magela da; Bowen, L. H.; Schwertmann, U.; Vandenberghe, Robert Emile
Seven A|-containing lepidocrocite samples, ~/-Fe,_xAlxOOH, prepared from FeC12/AI(NO3)3 solutions with initial A1/(A1 + Fe) mole ratios C~ of 0.0025, 0.01, 0.025, 0.05, 0.075, 0.10 and 0.15 tool/ mol, were examined by means of M6ssbauer spectroscopy at room temperature (RT) and at various temperatures in the range of 8 to 80 K. The spectra at RT and 80~ consist of broadened quadrupole doublets and were analyzed in terms of a single doublet and of a model-independent quadrupole-splitting distribution, the latter yielding the best fit. The observed variations of the quadrupole-splitting parameters with increasing C i are inconclusive as to whether the A1 cations are substituting into the structure. The temperature at which the onset of magnetic ordering is reflected in the spectra, was measured by the therrnoscan method with zero source velocity. A gradual shift from 50 K for Ci = 0.0025 mol/mol to 44 K for Ci = 0.10 mol/mol was observed for that temperature. As compared to earlier studies of Al-free ~-FeOOH samples with similar morphological characteristics, the fractional doublet area in the mixed sextet-doublet spectra at 35 K is significantly higher for the present lepidocrocites. This observation is ascribed to the substitution of A1 cations into the lepidocrocite structure. A similar conclusion is inferred from the variation with C~ of the maximum-probability hyperfine field derived from the spectra recorded at 8 K and fitted with a model-independent hyperfine-field distribution. The magnetic results suggest that for the sample corresponding to Ci = 0.15 mol/mol, not all of the initially present A1 has been incorporated into the structure.
57Fe-Mössbauer spectroscopy on natural eosphorite-childrenite-ernstite samples.
(2005) Costa, Geraldo Magela da; Cipriano, Ricardo Augusto Scholz; Karfunkel, Joachim; Bermanec, Vladimir; Chaves, Mario Luiz de Sá Carneiro
Samples of the eosphorite-childrenite [(Mn2+, Fe2+)AlPO4(OH)2H2O] series from Divino das Laranjeiras and Araçuaí (Minas Gerais State) and Parelhas (Rio Grande do Norte State) pegmatites have been investigated by X-ray diffraction, microprobe analysis and Mössbauer spectroscopy at 295 and 77 K. The Mössbauer spectra of ernstite [(Mn2+, Fe3+)Al- PO4(OH)2-xOx] showed the existence of ferric ions in both A and B sites, whereas ferrous ions seem to be located exclusively in the A site. Nonoxidised samples show ferrous ions located in both sites, and no Fe3+ could be detected. The interpretation of the Mössbauer spectra of both, oxidised and nonoxidised samples, is difficult because the hyperfine parameters of these minerals are rather similar, rendering it difficult to make proper site assignments.
5th International Conference on Variable Neighborhood Search (ICVNS'17).
(2018) Coelho, Vitor Nazário; Santos, Haroldo Gambini; Coelho, Igor Machado; Penna, Puca Huachi Vaz; Oliveira, Thays Aparecida de; Souza, Marcone Jamilson Freitas; Sifaleras, Angelo
This volume presents selected, peer-reviewed, short papers that were accepted for presentation in the 5th International Conference on Variable Neighborhood Search (ICVNS'17) which was held in Ouro Preto, Brazil, during October 2–4, 2017.
7-Chloroquinolinotriazoles : synthesis by the azide-alkyne cycloaddition click chemistry, antimalarial activity, cytotoxicity and SAR studies.
(2014) Pereira, Guilherme Rocha; Brandão, Geraldo Célio; Arantes, Lucas Micquéias; Oliveira Junior, Haliton Alves de; Paula, Renata Cristina de; Nascimento, Maria Fernanda Alves do; Santos, Fábio Mendes dos; Rocha, Ramon Kleber da; Lopes, Júlio César Dias; Oliveira, Alaíde Braga de
Twenty-seven 7-chloroquinolinotriazole derivatives with different substituents in the triazole moiety were synthesized via copper-catalyzed cycloaddition (CuAAC) click chemistry between 4-azido-7- chloroquinoline and several alkynes. All the synthetic compounds were evaluated for their in vitro activity against Plasmodium falciparum (W2) and cytotoxicity to Hep G2A16 cells. All the products disclosed low cytotoxicity (CC50 > 100 mM) and five of them have shown moderate antimalarial activity (IC50 from 9.6 to 40.9 mM). As chloroquine analogs it was expected that these compounds might inhibit the heme polymerization and SAR studies were performed aiming to explain their antimalarial profile. New structural variations can be designed on the basis of the results obtained.