244 resultados para HYPERVALENT IODINE(III) REAGENT
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Philipotabanus (Mimotabanus) henriquesi sp. nov. é descrita e ilustrada baseada em 30 fêmeas e dois machos coletados em vegetação de Cerrado, nos municípios de Carolina, Alto Parnaíba e Mirador, região sul do estado do Maranhão, Brasil. Este é o primeiro registro de uma espécie do subgênero no Brasil.
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This paper registers reports about dipterans made by three Portuguese who lived in Brazil during the 18th century. Luiz Gomes Ferreira, in his book "Erário mineral" ["Mineral revenue"], wrote curious passages related with myiasis-causing flies of the genus Cochliomyia. José Rodrigues de Mello registered, in Latin verses, the folklore for curing myiases caused by Cochliomyia hominivorax in cattle. Luiz dos Santos Vilhena, in the last of his twenty letters dealing with several aspects of life in Brazil, made reference to horseflies, human bot flies and mosquitos.
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O objetivo principal deste trabalho foi analisar a variação dos fatores de retardamento (R) e dos coeficientes de dispersão-difusão (D) para o crômio (III) em dois solos muito intemperizados, considerando diferentes atributos edáficos: textura, pH e matéria orgânica. Utilizaram-se amostras dos horizontes A e B com diferença marcante no teor de matéria orgânica de dois solos coletados no estado de São Paulo: Latossolo Vermelho eutroférrico textura argilosa (LVe) e Latossolo Vermelho-Amarelo distrófico textura média (LVd). A alteração do pH das amostras do horizonte superficial foi realizada com adição de carbonato de cálcio para elevar a saturação por bases a 70%. Foram realizados experimentos de adsorção em condições estáticas e de lixiviação em colunas de solo, utilizando a teoria do deslocamento miscível. Os Rs obtidos para o LVe foram maiores em comparação aos obtidos para o LVd. O aumento do pH do solo propiciado pela adição de carbonato de cálcio resultou em aumento no R. No LVe, a presença significativa de ácidos fúlvicos na matéria orgânica propiciou um R menor no horizonte superficial em relação ao subsuperficial. Não foi evidenciada relação nítida entre D e os diferentes solos, níveis de calagem e horizontes.
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In order to investigate the efficiency of sulfate green rust (GR2) to remove Ni from solution, GR2 samples were synthesized under controlled laboratory conditions. Some GR2 samples were synthesized from Fe(II) and Fe(III) sulfate salts by precipitation. Other samples were prepared by coprecipitation, of Ni(II), Fe(II) and Fe(III) sulfate salts, i.e., in the presence of Ni. In another sample, Ni(II) sulfate salt was added to pre-formed GR2. After an initial X-ray diffraction (XRD) characterization all samples were exposed to ambient air in order to understand the role of Ni in the transformation of the GR2 samples. XRD was repeated after 45 days. The results showed that Nious GR2 prepared by coprecipitation is isomorphous to Ni-free GR2, i.e. Ni is incorporated into the crystalline structure. Fe(II) was not replaced by Ni(II) in the crystalline structure of GR2 formed prior to exposure to solution-phase Ni. This suggests Ni was adsorbed to the GR2 surface. Sulfate green rust is more efficient in removing Ni from the environment by coprecipitation.
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Ni(II)-Fe(II)-Fe(III) layered double hydroxides (LDH) or Ni-containing sulfate green rust (GR2) samples were prepared from Ni(II), Fe(II) and Fe(III) sulfate salts and analyzed with X ray diffraction. Nickel is readily incorporated in the GR2 structure and forms a solid solution between GR2 and a Ni(II)-Fe(III) LDH. There is a correlation between the unit cell a-value and the fraction of Ni(II) incorporated into the Ni(II)-GR2 structure. Since there is strong evidence that the divalent/trivalent cation ratio in GR2 is fixed at 2, it is possible in principle to determine the extent of divalent cation substitution for Fe(II) in GR2 from the unit cell a-value. Oxidation forms a mixture of minerals but the LDH structure is retained if at least 20 % of the divalent cations in the initial solution are Ni(II). It appears that Ni(II) is incorporated in a stable LDH structure. This may be important for two reasons, first for understanding the formation of LDHs, which are anion exchangers, in the natural environment. Secondly, this is important for understanding the fate of transition metals in the environment, particularly in the presence of reduced Fe compounds.
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A good knowledge of the spatial distribution of clay minerals in the landscape facilitates the understanding of the influence of relief on the content and crystallographic attributes of soil minerals such as goethite, hematite, kaolinite and gibbsite. This study aimed at describing the relationships between the mineral properties of the clay fraction and landscape shapes by determining the mineral properties of goethite, hematite, kaolinite and gibbsite, and assessing their dependence and spatial variability, in two slope curvatures. To this end, two 100 × 100 m grids were used to establish a total of 121 regularly spaced georeferenced sampling nodes 10 m apart. Samples were collected from the layer 0.0-0.2 m and analysed for iron oxides, and kaolinite and gibbsite in the clay fraction. Minerals in the clay fraction were characterized from their X-ray diffraction (XRD) patterns, which were interpreted and used to calculate the width at half height (WHH) and mean crystallite dimension (MCD) of iron oxides, kaolinite, and gibbsite, as well as aluminium substitution and specific surface area (SSA) in hematite and goethite. Additional calculations included the goethite and hematite contents, and the goethite/(goethite+hematite) [Gt/(Gt+Hm)] and kaolinite/(kaolinite+gibbsite) [Kt/(Kt+Gb)] ratios. Mineral properties were established by statistical analysis of the XRD data, and spatial dependence was assessed geostatistically. Mineralogical properties differed significantly between the convex area and concave area. The geostatistical analysis showed a greater number of mineralogical properties with spatial dependence and a higher range in the convex than in the concave area.
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É apresentado o resultado da primeira seleção de 25 clones de seringueira (Hevea brasiliensis (Willd. ex Adr. de Juss.) Müell. Arg.), a maior parte constituída de introduções de diferentes origens. Após multiplicados, foram avaliados em experimentos do tipo pequena escala, obedecendo ao delineamento de blocos ao acaso, instalado na Estação Experimental de Votuporanga, SP. Os caracteres avaliados foram: produção de borracha seca, vigor expresso pelo perímetro do caule, espessura de casca e número de anéis de vasos laticíferos. Com relação à produção de borracha seca, destacaram-se os clones IAN 3156, IAC 40, 7/6, 3/5 e 3/1, produzindo 124%, 105%, 27%, 26% e 19% superiores em relação ao RRIM 600, recomendando-se seu plantio em pequena escala na região de Jaú. Caracteres secundários tais como o vigor, espessura de casca e número de anéis de vasos laticíferos dos clones testados são também discutidos. Sugere-se sua avaliação em experimentos do tipo grande escala com o objetivo de avaliar, além da produção, outros caracteres secundários para futuras recomendações no Estado de São Paulo.
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Este trabalho tem por objetivo fazer uma revisão da anatomia e das principais doenças do III par craniano, demonstrando-as através de estudos por imagem, com ênfase em ressonância magnética. Os métodos de imagem são peça fundamental na avaliação de pacientes com suspeita de lesão do nervo oculomotor, uma vez que o quadro clínico é freqüentemente inespecífico e a gama de doenças que podem acometê-lo é bastante ampla. Realizamos também breve levantamento da literatura.
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OBJETIVO: Utilizar a cintilografia óssea facial para identificar o crescimento esquelético mandibular, através do metabolismo ósseo condilar de indivíduos com crescimento craniofacial equilibrado, e compará-lo à atividade condilar daqueles com crescimento mandibular excessivo. MATERIAIS E MÉTODOS: Quarenta e sete indivíduos, de ambos os sexos, entre 18 e 28 anos de idade, foram divididos em grupo controle - classe I (n = 13) - e grupo caso - classe III (n = 34). As imagens foram obtidas duas horas após injeção intravenosa de 200 µCi/kg de 99mTc-MDP. Foram realizadas incidências laterais do crânio e posterior da coluna lombar e a taxa de contagem foi determinada pela obtenção da média de contagem dos côndilos e da quarta vértebra lombar utilizando 300.000 contagens. RESULTADOS: Não foram encontradas captações condilares assimétricas em ambos os grupos, e apesar da ausência de significância estatística, os valores médios de captação condilar foram maiores no grupo caso. CONCLUSÃO: A média de captação aumentada indicou maior metabolismo ósseo condilar nos indivíduos classe III, sugerindo um provável crescimento mandibular residual. Mais estudos estão sendo realizados para aumentar esta amostragem.
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OBJETIVO: Analisar a eficiência da angioplastia primária infra-inguinal como método de salvamento de membros em pacientes portadores de lesões tróficas por isquemia crítica. MATERIAIS E MÉTODOS: Foram analisados 36 pacientes submetidos a angioplastias primárias sem stent. Todos os pacientes apresentavam isquemia crítica com lesão trófica - grau III, categoria 5 de Rutherford -, sendo 17 lesões na artéria femoral superficial, 16 na artéria poplítea e 51 em artérias da perna, totalizando 84 angioplastias. Foram analisadas também as prevalências em relação a sexo, membro afetado, idade e principais comorbidades, sendo tecidas considerações técnicas sobre os procedimentos, assim como os materiais utilizados. RESULTADOS: Considerou-se sucesso quando a lesão trófica que motivou a angioplastia cicatrizou, ou o nível de amputação limitou-se a artelhos ou ao antepé, sem ter havido necessidade de procedimento cirúrgico de reconstituição do fluxo sanguíneo (bypass), independentemente de tempo, drogas associadas e números de desbridamentos realizados. CONCLUSÃO: As angioplastias no segmento femoropoplíteo e infrapoplíteo são procedimentos de elevado sucesso técnico, baixa morbidade e mortalidade, constituindo-se procedimento eficaz em pacientes com isquemia crítica de membro inferior.
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Objective To evaluate the relationship between two year PSA nadir (PSAn) after brachytherapy and biochemical recurrence rates in prostate cancer patients. Materials and Methods In the period from January 1998 to August 2007, 120 patients were treated with iodine-125 brachytherapy alone. The results analysis was based on the definition of biochemical recurrence according to the Phoenix Consensus. Results Biochemical control was observed in 86 patients (71.7%), and biochemical recurrence, in 34 (28.3%). Mean PSAn was 0.53 ng/ml. The mean follow-up was 98 months. The patients were divided into two groups: group 1, with two year PSAn < 0.5 ng/ml after brachytherapy (74 patients; 61.7%), and group 2, with two year PSAn ≥ 0.5 ng/ml after brachytherapy (46 patients; 38.3%). Group 1 presented biochemical recurrence in 15 patients (20.3%), and group 2, in 19 patients (43.2%) (p < 0.02). The analysis of biochemical disease-free survival at seven years, stratified by the two groups, showed values of 80% and 64% (p < 0.02), respectively. Conclusion Levels of two year PSAn ≥ 0.5 ng/ml after brachytherapy are strongly correlated with a poor prognosis. This fact may help to identify patients at risk for disease recurrence.
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QSAR studies based on flow microcalorimetric bioassay data for interaction of homologous series of m-alkoxyphenols and p-hydroxybenzoates with E. coli cells were carried out applying factorial design. Results for both series showed a linear relationship between log(dose)max and log Po/w. Analysis of these data allows the identification of contributions toward the derived bioactivity from the parent structures (the molecule minus n-CH2 groups present in the side-chain) and the lipophilic groups, CH2. These results are discussed with respect to drug quantitative structure-relationship.
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Silica gel was functionalized with [3-(2-aminoethyl)aminopropyl]trimethoxysilane group (SF-AEATS) and the characterization by chemical analysis (N) and infrared spectroscopy confirmed the functionalization. The capacity of the modified silica to adsorb the complex Ru(III)-EDTA from ethanolic solution was studied. The selectivity coefficients of the complex formed on the support obtained was (Gñ), 2,07 x 10(4) L/mol and the average number of ligand bonded by one metal ion on the support (ñ) was ~ 1.
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Didactic experiments are proposed in order to demonstrate the characteristics of flow injection analysis and to extend the applications of FIA to the determination of physical chemistry parameters in undergraduate labs. All experiments can be performed with the same flow manifold by employing usual FIA devices. Analytical characteristics are presented by means of the determination of iron in river water, employing 1,10-phenantroline as chromogenic reagent. Physical chemistry applications were the determination of reaction stoichiometries by continuous variation and mole-ratio methods and the evaluation of the pH and ionic strength effects on the kinetic of the reduction of hexacianoferrate(III) by ascorbic acid.
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The present work proposes the application of the 4-Hidroxy-3-(2-hydroxynaphtylazo)-benzenesulphonic acid (C.I. 15670), Alizarine Violet N (AVN), as a reagent for direct aluminium determination using molecular absorption spectrophotometry in the presence of tensoatives. Al(III) cation reacts with AVN in pH 9.4, forming a red complex, stable for at least 24 hours, with absorption minimum at 607nm and, against a reagent blank, (epsiloncomplex - epsilonreagent) = -2.71x10(4) L.mol-1.cm-1. The reaction occurs in the presence of a Triton-X100 and CTAB tensoatives mixture, in the presence of EDTA. Al(III) determination is possible in the linear range of 50 up to 400ng.mL-1, with a detection limit of 41 ng.mL-1.