Infusions of Mikania glomerata Sprengel (guaco) leaves are used in Brazil for the treatment of respiratory diseases. Coumarin is the chemical marker of guaco for quality control purposes. This work proposes a voltammetric methodology to determine coumarin by using a boron-doped diamond electrode. At pH 10 (0.1 mol L-1 Britton-Robinson buffer solution), coumarin is irreversibly oxidized around +1.77 V in a process predominantly controlled by diffusion. The methodology described here presented a linear range from 1.54 to 15.3 µg mL-1 with limits of detection and quantification of 0.20 and 0.62 µg mL-1, respectively. Analysis of variance confirmed the significance of the regression and the absence of lack-of-fit at the confidence level of 95%. Infusion of commercial guaco leaves was directly analyzed, and results were in agreement with high-performance liquid chromatography after applying the paired t-test at a confidence level of 95%.

Abstract The structural condition of the cable-stayed towers anchorage on power transmission lines requires constant monitoring. Maintenance routines must be able to identify faulty anchor rods and substitute them to avoid tower collapses and power delivery interruptions. Modern statistical diagnostic systems based on machine learning requires the generation of several distinct rod sample signals to be trained, which is a time-consuming process in typical electromagnetic solvers. Aiming to generate samples in a feasible time span, this paper presents a modeling strategy based on the cascade analysis of the transmission line composed by the anchor and the reference rods, interconnected by a dedicated high-frequency connector. Each distinct transmission line part is modeled by a quadrupole as a partial ABCD matrix. The complete response for each experimental setup is obtained from the cascaded-multiplying of the partial matrices. The proposed modeling proved to be accurate and provides a faster way to obtain the S-parameters from distinct faulty rods if compared to the traditional methodologies using electromagnetic tools.

In this work, we examined how photoluminescence in poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) is affected by morphology, dictated by the mode of preparation. For that, MEH-PPV dilute solutions in good and non-solvents, thick cast films with poly[methylmethacrylate] (PMMA) as inert matrix and spin-coated thin films were prepared. These systems were studied by steady-state and time-dependent fluorescence spectroscopy and electronic microscopy. Unexpected photoluminescent behavior was detected in solutions and films and it was related to different excitons modulated by MEH-PPV conformation. By semi empirical calculations we obtained the singlet and triplet state energies of an MEH-PPV model system and, from time-resolved fluorescence spectroscopy, the existence of short-lived excited states was revealed, enabling us to infer on possible singlet fission in MEH-PPV-based systems.

O objetivo do presente estudo foi avaliar quatro modelos matemáticos quanto ao seu ajuste a curvas de lactação de vacas Holandesas pertencentes a rebanhos da região sudoeste do estado do Paraná, Brasil. Inicialmente 42.281 controles de produções leiteiras referentes aos anos de 2005 a 2011, foram da "Associação Paranaense de Criadores de Bovinos da Raça Holandesa (APCBRH)". Os dados que não possuíam a data de secagem e a produção total aos 305 dias foram excluídos, restando 15.142 controles referentes a 2.441 vacas Holandesas. Os dados foram classificados de acordo com a ordem de parição (variando de um a seis), e dentro de cada ordem de parição os animais foram separados em quartis (Q25%, Q50%,Q75% e Q100%) conforme a produção total aos 305 dias. Para cada ordem de parição, em cada quartil foram ajustados quatro modelos matemáticos, dois predominantemente empíricos (modelo de Brody e de Wood) e dois com características mais mecanicistas (modelo de Dijkstra e de Pollott). A qualidade de ajuste foi avaliada pelo critério de Akaike corrigido. O modelo de Wood apresentou o melhor ajuste em quase todas as situações avaliadas e, portanto, deve ser considerado como o melhor modelo para descrever, pelo menos empiricamente, as curvas de lactação de vacas Holandesas criadas no Sudoeste do Paraná.

The objective of this study was to evaluate four mathematical models with regards to their fit to lactation curves of Holstein cows from herds raised in the southwestern region of the state of Parana, Brazil. Initially, 42,281 milk production records from 2005 to 2011 were obtained from "Associação Paranaense de Criadores de Bovinos da Raça Holandesa (APCBRH)". Data lacking dates of drying and total milk production at 305 days of lactation were excluded, resulting in a remaining 15,142 records corresponding to 2,441 Holstein cows. Data were sorted according to the parity order (ranging from one to six), and within each parity order the animals were divided into quartiles (Q25%, Q50%, Q75% and Q100%) corresponding to 305-day lactation yield. Within each parity order, for each quartile, four mathematical models were adjusted, two of which were predominantly empirical (Brody and Wood) whereas the other two presented more mechanistic characteristics (models Dijkstra and Pollott). The quality of fit was evaluated by the corrected Akaike information criterion. The Wood model showed the best fit in almost all evaluated situations and, therefore, may be considered as the most suitable model to describe, at least empirically, the lactation curves of Holstein cows raised in Southwestern Parana.

This work describes the local knowledge of the medicinal use of Stryphnodendron rotundifolium Mart., Fabaceae, according to informants in two areas of the Araripe bioregion, in the Northeast Region of Brazil. We used interviews to investigate the ethnomedicinal use of the local species to determine the mode of use, frequency of administration, duration of treatment and restrictions of use. In traditional medicine, the use of S. rotundifoliumis associated with the treatment of inflammatory and infectious diseases. The part of the plant most used was the stem bark (86.11%), the predominant mode of preparation was immersion in water (52.83%), and oral administration was the most cited (48.43%). For inflammatory and infectious diseases, the treatment lasted 3-10 days and the frequency of administration was 2-3 times/day. For gastroprotective effects, treatment lasted up to 30 days, and the herb was administered 1-3 times/day. For pain complaints, the therapy varied from 2-3 days to continuous administration.The informants (46.87%) did not mention restrictions of use, except for pregnant women, with a rate of 25%. A comparison of these results with the ethnopharmacological information from other studies showed that some of the traditional indications are scientifically supported by the literature or clinical studies. Nevertheless, the results showed that pharmacologists have not fully investigated all the possible bioactivities that healers credit to this plant.

Observou-se, em estudo preliminar, que o extrato metanólico das folhas de L. lilacina, coletadas no município de Lavras (MG, Brasil), apresentava atividade antibacteriana. Em decorrência, buscou-se purificar e identificar a substância responsável por tal efeito, através de fracionamento do referido extrato direcionado por testes de difusão em agar com Aeromonas hydrophila, Bacillus subtilis, Pseudomonas aeruginosa e Staphylococcus aureus. Após partições com solventes e vários processos cromatográficos, isolou-se o [β-3,4-diidroxifenil)etil]-(3'-O-α-L-ramnopiranosil)-(4'- O-cafeoil)-β-D-glicopiranosídeo, que é conhecido como acteosídeo. A concentração inibitória mínima e a concentração bactericida mínima desta substância para A. hydrophila, B. subtilis, P. aeruginosa e S. aureus foram de 0,12, 1,00, 1,00 e 0,25 mg/mL, respectivamente.

Since the methanol extract of Lantana lilacina leaves collected in the city of Lavras (MG, Brazil) showed antibacterial properties in a preliminary study, a fractionation process guided by agar diffusion assays with Aeromonas hydrophila, Bacillus subtilis, Pseudomonas aeruginosa and Staphylococcus aureus was carried out to purify and identify the active compounds. After solvent partition and several chromatographic steps, [ß-3,4-dihydroxyphenyl)-ethyl]-(3'-O-α-L-rhamnopyranosyl)-(4'- O-cafeoyl)-β-D-glycopyranoside, known as acteoside, was isolated. The minimal inhibition concentration and the minimal bactericidal concentration of such substance against A. hydrophila, B. subtilis, P. aeruginosa and S. aureus were 0.12, 1.00, 1.00 and 0.25 mg/mL, respectively.