Classificação de biodiesel na região do visível

Classification of biodiesel by oilseed type using pattern recognition techniques is described. The spectra of the samples were performed in the Visible region, requiring noise removal by use of a first derivative by the Savitzky-Golay method, employing a second-order polynomial and a window of 21 points. The characterization of biodiesel was performed using HCA, PCA and SIMCA. For HCA and PCA methods, one can observe the separation of each group of biodiesel in a spectral region of 405-500 nm. SIMCA model was used in a test group composed of 28 spectral measurements and no errors are obtained.

Identificação de extratos etanólicos de madeiras utilizando seu espectro eletrônico de absorção e análise multivariada

The application of multivariate analysis to spectrophotometric (UV) data was explored for distinguishing extracts of cachaça woods commonly used in the manufacture of casks for aging cachaças (oak, cabreúva-parda, jatobá, amendoim and canela-sassafrás). Absorbances close to 280 nm were more strongly correlated with oak and jatobá woods, whereas absorbances near 230 nm were more correlated with canela-sassafrás and cabreúva-parda. A comparison between the spectrophotometric model and the model based on chromatographic (HPLC-DAD) data was carried out. The spectrophotometric model better explained the variance data (PC1 + PC2 = 91%) exhibiting potential as a routine method for checking aged spirits.

Comparação do perfil químico entre cachaças de um mesmo vinho destiladas em alambiques e em colunas

Six wines were distilled in two different distillation apparatus (alembic and column) producing 24 distillates (6 for each alembic fraction - head, heart and tail; 6 column distillates). The chemical composition of distillates from the same wine was determined using chromatographic techniques. Analytical data were subjected to Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) allowing discrimination of four clusters according to chemical profiles. Both distillation processes influenced the sugarcane spirits chemical quality since two types of distillates with different quantitative chemical profiles were produced after the elimination of fermentation step influence.

Highly improved chromium (III) uptake capacity in modified sugarcane bagasse using different chemical treatments

The present paper focuses on improving chromium (III) uptake capacity of sugarcane bagasse through its chemical modification with citric acid and/or sodium hydroxide. The chemical modifications were confirmed by infrared spectroscopy, with an evident peak observed at 1730 cm-1, attributed to carbonyl groups. Equilibrium was reached after 24 h, and the kinetics followed the pseudo-second-order model. The highest chromium (III) maximum adsorption capacity (MAC) value was found when using sugarcane bagasse modified with sodium hydroxide and citric acid (58.00 mg g-1) giving a MAC value about three times greater (20.34 mg g-1) than for raw sugarcane bagasse.

Determination of levodopa in human plasma by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS): application to a bioequivalence study

A sensitive, accurate and simple method using HPLC-MS/MS was developed and validated for levodopa quantitation in human plasma. Analysis was achieved on a pursuit® C18 analytical column (5 µm; 150 x 4.6 mm i.d.) using a mobile phase (methanol and water , 90:10, v/v) containing formic acid 0.5% v/v, after extracting the samples using a simple protein plasma precipitation with perchloric acid. The developed method was validated in accordance with ANVISA guidelines and was successfully applied to a bioequivalence study in 60 healthy volunteers demonstrating the feasibility and reliability of the proposed method.

Decaimento de íons cianato e a formação de carbamato de etila

Cyanate ion stability was studied in aqueous/ethanolic solutions, pH = 4.5 (CH3COOH/NaCH3COO), at different temperatures. Following the decay [(OCN)-] versus time, in the presence of excess C2H5OH, the rate constant for this reaction (k1) was calculated as (2.5 ± 0.3) x 10-4 s-1 at 25 ºC, for 0 < [C2H5OH] < 13.7 x 10-1 mol L-1. For [C2H5OH] > 2.0 mol L-1 a decrease in the numerical value of k1 was observed, reaching 5.2 x 10-5 s-1 when [CH3CH2OH] = 13.7 mol L-1. Variations in the kinetic parameter values ΔH1‡, ΔS1‡ and ΔG1‡ for the cyanate ion decay reaction were observed for solutions at different ethanol concentrations.

Influence of chloride-mediated oxidation on the electrochemical degradation of the direct black 22 dye using boron-doped diamond and β-PbO2 anodes

The Direct Black 22 dye was electrooxidized at 30 mA cm-2 in a flow cell using a BDD or β-PbO2 anode, varying pH (3, 7, 11), temperature (10, 25, 45 °C), and [NaCl] (0 or 1.5 g L-1). In the presence of NaCl, decolorization rates were similar for all conditions investigated, but much higher than predicted through a theoretical model assuming mass-transport control; similar behavior was observed for COD removal (at pH 7, 25 °C), independently of the anode. With no NaCl, COD removals were also higher than predicted with a theoretical model, which suggests the existence of distinct dye degradation pathways.

INVESTIGAÇÃO DA SUPRESSÃO DE FLUORESCÊNCIA DE SORO ALBUMINA BOVINA E HUMANA POR COMPLEXO DE RUTÊNIO

The binding of [RuCl2(L)] (L = N,N-bis(7-methyl-2-pyridylmethylene)-1,3-diiminopropane) to bovine and human serum albumin was investigated by the fluorescence quenching technique. The comparison of the quenching effect of serum albumin fluorescence by ruthenium complex allowed the estimation of subdomain IB in BSA and subdomain IIA in HSA as the binding sites for this complex. The results of fluorescence titration revealed that ruthenium complex quenches the intrinsic fluorescence of BSA through a dynamic quenching mechanism, while HSA has a static quenching mechanism. The thermodynamic parameters indicated that hydrophobic forces played a major role in the binding of ruthenium complex to proteins. The process of binding was a spontaneous process in which Gibbs free energy change was negative.

DESENVOLVIMENTO DE UMA TÉCNICA ULTRASSÔNICA PARA AVALIAR TEORES DE ÓLEO E GRAXA EM EFLUENTES DE BIOCOMBUSTÍVEIS

Ultrasound as a metrology tool has many applications in health care, industrial, and chemical analyses. Ultrasonic techniques are rapid, low-cost, non-invasive, and highly repeatable. Although ultrasound can be used to measure emulsions, no effort had been made thus far to optimize its sensitivity for metrological analysis. In this work, a technique for analyzing oil in water was validated. The wave velocity and attenuation were chosen as the ultrasonic parameters. The technique was implemented in the boundary region established by law for effluents from industrial plants involved with biofuel manufacturing. A technical effort of this study was to establish stable emulsions in concentrations close to the desired limit of study. The phase behaviours of pseudo-ternary oil, sodium chloride, and sodium lauryl sulphate were studied. The composition in the widest region of the diagram allowed for the formation of a stable emulsion, from which the ultrasound measurement was carried out. An analytical curve was obtained using ultrasonic attenuation to determine the content of oils and greases in wastewater ranging 15–240 ppm. The speed of sound did not appear to be an applicable parameter for this application. The technique was demonstrated to be an important alternative solution for the continuous monitoring of wastewater with regard to oil concentrations.

SÍNTESE DE DERIVADOS DE FENANTRIDINONAS POR ARILAÇÃO DIRETA. CARACTERIZAÇÃO DOS ESPECTROS DE ABSORÇÃO E EMISSÃO DE EXEMPLOS REPRESENTATIVOS

The phenanthridinone heterocyclic system has attracted considerable attention in recent years due to the diverse array of physical, chemical and pharmacological properties demonstrated by natural and synthetic derivatives. As a consequence there has been considerable development of synthetic methodology for the synthesis of this and related heterocyclic ring systems. The synthetic literature is discussed and is compared with a direct arylation methodology for the intramolecular cyclization of tertiary (2-iodo)benzoylamides to generate the biaryl bond of these compounds. The efficient methodology allowed the synthesis of a number of previously unknown phenanthridinone products. The photoluminescent properties of representative examples were characterized and it is proposed that the previously unknown compound 1s reveals dual fluorescence in a manner similar to the known compound 1r.

Detection and partial characterization of an isolate of Groundnut ringspot virus in Solanum sessiliflorum

The cubiu (Solanum sessiliflorum) fruit, originating in the Amazon basin, is commonly used in that region for food, medicine, and cosmetics. In an experimental culture of cubiu, in order to evaluate its adaptation to conditions in the Northern region of the state of Rio de Janeiro, it was observed plants with mosaic symptoms. A cubiu plant was collected and analyzed to identify the etiological agent. After mechanical passage through a local lesion host, a host range test was performed. The virus induced chlorotic local lesions in Chenopodium quinoa, necrotic local lesions in Gomphrena globosa, mosaic in S. sessiliflorum, leaf and stem necrosis in tomato (Lycopersicon esculentum) 'Rutgers', mosaic and leaf distortion in Datura stramonium and Physalis floridana, and necrotic local lesions followed by systemic necrosis and plant death in four Nicotiana species. Electron microscopic observations of ultra thin sections from infected cubiu leaves showed the presence of spheroidal, membrane-bound particles typical of tospovirus species. Analysis of the nucleocapsid protein from concentrated virus particles indicated the presence of a 28 kDa protein. RT-PCR was performed after total RNA extraction from infected IPA-6 tomato leaves. A fragment of approximately 0,8 kbp corresponding to the N gene was amplified, cloned and sequenced. The N protein from the cubiu isolate was 95% homologous to the Groundnut ringspot virus (GRSV) protein, and no more than 85% homologous to those from Zucchini lethal chlorosis virus (ZLCV) and Chrysanthemun stem necrosis virus (CSNV), Tomato spotted wilt virus (TSWV), and Tomato chlorotic spot virus (TCSV). This is the first report of the occurrence of GRSV (or any other plant virus) in cubiu.

Kielellisen käänteen raunioilla

Kirjallisuusarvostelu

Hipersensibilidade e necrose sistêmica em Nicotiana benthamiana transformada com o gene de resistência Sw-5 de tomateiro

O gene Sw-5 do tomateiro confere resistência a várias espécies de tospovírus e codifica uma proteína contendo domínios de ligação a nucleotídeos e repetições ricas em leucina. Tomateiros com Sw-5 exibem reações necróticas nas folhas inoculadas com tospovírus. Estas reações e a estrutura da proteína Sw-5 indicam que a resistência ocorre por meio do reconhecimento do patógeno e desencadeamento da resposta de hipersensibilidade. A capacidade de Sw-5 de conferir resistência a tospovírus em tabaco selvagem (Nicotiana benthamiana Domin.) foi avaliada em plantas transgênicas. Uma construção com a seqüência aberta de leitura de Sw-5 e sua região 3’ não-traduzida sob controle do promotor 35S do CaMV foi utilizada para transformação de N. benthamiana via Agrobacterium tumefaciens. Plantas de progênies R1 foram inoculadas com um isolado de tospovírus e avaliadas quanto à ocorrência de reação de hipersensibilidade e resistência à infecção sistêmica. Em uma progênie com segregação 3:1 (resistente:suscetível), foi selecionada uma planta homozigota e sua progênie avaliada quanto ao espectro da resistência a tospovírus. Plantas com o transgene exibiram resposta de hipersensibilidade 48 h após a inoculação, sendo resistentes à infecção sistêmica. O fenótipo da resistência foi dependente do isolado viral e um isolado de Tomato chlorotic spot virus (TCSV) causou necrose sistêmica em todas as plantas inoculadas, enquanto que isolados de Groundnut ringspot virus (GRSV) e um isolado relacionado a Chrysanthemum stem necrosis virus (CSNV) ficaram restritos ao sítio de infecção. Comparações do espectro da resistência obtido neste trabalho com aquele observado em outros membros da família Solanaceae indicam que as vias de transdução de sinais e as respostas de defesa ativadas por Sw-5 são conservadas dentro desta família e polimorfismos genéticos nas vias de transdução de sinais ou em componentes das respostas de defesa podem resultar em diferentes níveis de resistência.

Ralstonia solanacearum em viveiros clonais de eucalipto no Brasil

A incidência da murcha bacteriana, causada por Ralstonia solanacearum, em viveiros clonais de eucalipto, no período de abril a setembro de 2005, resultou no descarte de cerca de 553.991 minicepas, 6.837.691 propágulos na fase de enraizamento e 11.266.819 mudas, nos Estados da Bahia, do Espírito Santo, do Maranhão, de Minas Gerais e do Pará, totalizando um prejuízo estimado em, no mínimo, seis milhões de reais (US$ 2,7 milhões). Em minijardim clonal, a doença caracteriza-se por necrose foliar, escurecimento anelar ou completo do lenho, murcha e morte de minicepas. Os sintomas na parte aérea são similares à morte gradual de minicepas submetidas a podas drásticas ou com sistema radicular malformado. Na fase de enraizamento, miniestacas infectadas podem apresentar arroxeamento das nervuras do limbo foliar e podridão. No campo, a doença caracteriza-se por bronzeamento e necrose foliar, desfolha basal, ascendente escurecimento interno do lenho e morte da planta, geralmente a partir do quarto mês após o transplantio. Os sintomas geralmente se agravam em árvores com enovelamento de raízes e afogamento de coleto. A etiologia da doença foi confirmada por meio de testes de exsudação, microscopia de varredura, isolamento da bactéria, análises de PCR/RFLP, reação de hipersensibilidade (HR) em mudas de fumo, testes de patogenicidade em plântulas de eucalipto e tomate e re-isolamento da bactéria. Como o sistema de produção de mudas clonais de eucalipto é altamente favorável à multiplicação bacteriana e na falta de conhecimento sobre a resistência genética e de outras estratégias de controle da doença, é essencial evitar a introdução da bactéria em viveiros.

Extração do corante da beterraba (Beta vulgaris) para utilização como indicador ácido-base

No presente trabalho, foi investigado o comportamento do extrato aquoso e alcoólico da beterraba (Beta vulgaris) como um indicador ácido-base, tendo como objetivo principal despertar o interesse pelo uso dos indicadores naturais, como alternativa didática para transmissão dos conceitos de titulação, equilíbrio químico e a lei de Lambert-Beer. Para a realização dos experimentos foram utilizadas soluções padrão de ácido clorídrico (HCl), ácido acético e hidróxido de sódio (NaOH). Inicialmente foram feitos testes para avaliar a reversibilidade do sistema, e observou-se que a coloração passa de vermelho para amarela com adição de base e retorna para vermelho com adição do ácido, sendo possível sua utilização para explicação do equilíbrio químico. As análises de espectroscopia UV-vis mostraram que os espectros de absorção molecular na região do visível, apresentam diferentes característica, dando indícios que ocorreu modificação na estrutura do indicador em meio ácido e básico. Após as análises volumétricas constatou-se que os pontos de equivalência determinados com o indicador natural tiveram concordância com os obtidos pelo método potenciométrico. Além disso, os extratos aquosos e alcoólicos da beterraba apresentam potencial didático para a explicação da lei de Lambert-Beer, sendo que no meio ácido houve uma melhor correlação comparado com o meio básico.