Resumo A atividade antioxidante do mel de Tetragonisca angustula (TAH) e seu extrato etanólico (TAEE) foram investigados. Os níveis totais de fenólicos (TPC) e flavonóides (TFC) também foram avaliados. Os resultados para TPC foram 19,91 ± 0,38 e 29,37 ± 1,82 mg GAE g-1 e para TFC 0,20 ± 0,02 e 0,14 ± 0,01 mg QE g-1 de TAH e TAEE, respectivamente. As atividades antioxidantes foram 73,29 ± 0,49% e 93,36 ± 0,27% no ensaio DPPH● e 71,73 ± 4,07% e 97,86 ± 0,35% no ABTS●+ para TAH e TAEE, respectivamente. A atividade redutora total foi determinada pelo método de poder redutor (PR) e íon ferrico (Fe III) e os resultados variaram em PR de 151,7 ± 25,7 e 230,7 ± 25,2 mg GAE L-1, para TAH e TAEE respectivamente e para (Fe III) em EC50 0,284 em TAEE e 0,687 em TAH. A análise química por HPLC-DAD do extrato etanólico (TAEE) revelou a presença de ácido ferúlico como componente majoritário no extrato. A análise de RMN 1H confirmou esta estrutura e mostrou a presença de glicose, ácido cítrico, ácido succínico, prolina e derivados de hidrocarbonetos no TAEE. Além disso, a origem botânica também foi investigada e apresentou característica multifloral, tendo encontrado 19 tipos polínicos com predomínio botânico da família Anacardiaceae, sendo o pólen Tapirira predominante (42,6%) e o Schinus secundário (25,7%). Os resultados mostraram que o mel de T. angustula é uma interessante fonte de compostos fenólicos antioxidantes devido à sua origem floral e pode atuar como protetor da saúde humana quando consumido.

Abstract The antioxidant activity of Tetragonisca angustula honey (TAH) and its ethanolic extract (TAEE) were investigated. The total levels of phenolic (TPC) and flavonoids (TFC) were also evaluated. The results for TPC were 19.91 ± 0.38 and 29.37 ± 1.82 mg GAE g-1 and for TFC 0.20 ± 0.02 and 0.14 ± 0.01 mg QE g-1 of TAH and TAEE, respectively. Antioxidant activities were 73.29 ± 0.49% and 93.36 ± 0.27% in the DPPH● assay and 71.73 ± 4.07% and 97.86 ± 0.35% in ABTS●+ for TAH and TAEE, respectively. The total reducing activity was determined by the method of reducing power (PR) and iron ion (Fe III) and the results varied in PR from 151.7 ± 25.7 and 230.7 ± 25.2 mg GAE L-1, for TAH and TAEE respectively and for (Fe III) in EC50 0.284 in TAEE and 0.687 in TAH. Chemical analysis by HPLC-DAD of the ethanolic extract (TAEE) revealed the presence of ferulic acid as majority phenolic component in the extract. The 1H NMR analysis confirmed this structure and showed the also presence of glucose, citric acid, succinic acid, proline and hydrocarbon derivatives. In addition, the botanical origin was also investigated and showed a multifloral characteristic, having found 19 pollen types with a botanical predominance of the Anacardiaceae family, with Tapirira pollen occurring as predominant (42.6%) and Schinus as secondary (25.7%). The results showed that T. angustula honey is an interesting source of antioxidant phenolic compounds due to its floral origin and can act as a protector of human health when consumed.

Resumo O menor teor de lignina em espécies de plantas com potencial energético resulta na maior facilidade de quebra da celulose, disponibilizando glicose para geração de etanol. Porém, maiores teores de lignina representa um fator de resistência ao ataque de insetos. O objetivo deste trabalho foi avaliar como importantes pragas do sorgo energia, Diatraea saccharalis e Spodoptera frugiperda, se comportam quanto à alimentação e desempenho em sorgo bmr-6, um genótipo mutante com menor concentração de lignina. Foram realizados experimentos em laboratório e casa de vegetação, avaliando o desenvolvimento destas pragas nos híbridos de sorgo biomassa bmr 007, 008, TX635 e seus respectivos genótipos isogênicos convencionais (sem o gene bmr). O teor de lignina foi maior nos híbridos não bmr, mas nos parâmetros avaliados nos insetos, houve variação entre os tratamentos, não sendo consistente em apenas um híbrido e nem por ser ou não bmr. A menor sobrevivência de S. frugiperda foi verificada no híbrido BR008 tanto bmr quanto não bmr. As notas de injúria por S. frugiperda no sorgo em casa de vegetação foram altas (>7) em todos os tratamentos. Para D. saccharalis, não houve diferença significativa para a sobrevivência larval em laboratório, mas em casa de vegetação o híbrido BR007 tanto bmr quanto não bmr proporcionaram maior sobrevivência. Diante da necessidade de diversificar a matriz energética e o fato de que não foi comprovada neste estudo maior suscetibilidade dos híbridos bmr a ambas as pragas, estes resultados são promissores para o cultivo desses híbridos de sorgo biomassa para produção de biocombustíveis.

Abstract The lower lignin content in plants species with energy potential results in easier cellulose breakdown, making glucose available for ethanol generation. However, higher lignin levels can increase resistance to insect attack. The objective of this work was to evaluate the susceptibility of a bmr-6 biomass sorghum (a mutant genotype with a lower concentration of lignin) to important pests of energy sorghum, Diatraea saccharalis and Spodoptera frugiperda. Experiments were performed in the laboratory and greenhouse to evaluate the development of these pests on the biomass sorghum bmr hybrids BR007, BR008, and TX635 and their respective conventional near-isogenic genotypes (without the bmr gene). The lignin content was higher in non-bmr hybrids, but the evaluated insect variables varied between treatments, not being consistent in just one hybrid or because it is bmr or not. The lowest survival of S. frugiperda was observed in the BR008 hybrid, both bmr and non-bmr. The S. frugiperda injury scores on plants in the greenhouse were high (>7) in all treatments. For D. saccharalis, there was no difference in larval survival in the laboratory, but in the greenhouse, the BR007 hybrid, both bmr and non-bmr, provided greater survival. Due the need to diversify the energy matrix and the fact that greater susceptibility of the bmr hybrids to either pests was not found in this study, these results hold promise for cultivation of these biomass sorghum hybrids for the production of biofuels.

Resumo A cultura sanguínea de rotina é usada para a detecção de infecções na corrente sanguínea por bactérias aeróbias e anaeróbias e por leveduras patogênicas comuns. Estudo retrospectivo realizado em hospital público de Maceió-AL, por meio da coleta de dados de todos os prontuários com culturas sanguíneas positivas. Das 2.107 culturas sanguíneas realizadas, 17% foram positivas com Staphylococcus coagulase negativo (51,14%), seguido por Staphylococcus aureus (11,21%) e Klebsiella pneumoniae (6,32%). As bactérias Gram-positiva predominaram entre as culturas de sangue positivas, destacando-se o grupo das Staphylococcus coagulase-negativo. Enquanto as bactérias Gram-negativas apresentaram um número maior de espécies entre as culturas de sangue positivas.

Abstract Routine blood culture is used for the detection of bloodstream infections by aerobic and anaerobic bacteria and by common pathogenic yeasts. A retrospective study was conducted in a public hospital in Maceió-AL, by collecting data of all medical records with positive blood cultures. Out of the 2,107 blood cultures performed, 17% were positive with Staphylococcus coagulase negative (51.14%), followed by Staphylococcus aureus (11.21%) and Klebsiella pneumoniae (6.32%). Gram-positive bacteria predominated among positive blood cultures, highlighting the group of Staphylococcus coagulase-negative. While Gram-negative bacteria had a higher number of species among positive blood cultures.

Resumo A cultura da cana-de-açúcar Saccharum spp. (Poales: Poaceae) produz diferentes derivados para o mundo: açúcar, etanol e bioenergia. Apesar da aplicação de pesticidas, os insetos-praga ainda causam prejuízos econômicos, dentre eles a cochonilha rosada da cana-de-açúcar Saccharicoccus sacchari (Cockerell, 1895) (Hemiptera: Pseudococcidae) causando danos diretos e indiretos à planta. Este estudo avaliou a virulência de três espécies de nematoides entomopatogênicos (NEPs) e suas bactérias simbiontes contra a cochonilha rosada da cana-de-açúcar, em condições de laboratório. Quatorze tratamentos representados pelo controle (água destilada), Heterorhabditis bacteriophora Poinar, 1976 (HB EN01) (Rhabditida: Heterorhabditidae), Steinernema rarum (Doucet, 1986) (PAM25) e Steinernema carpocapsae Weiser, 1955 (All) (Rhabditida: Steinermatidae) nas concentrações de 25, 50, 75 e 100 juvenis infectantes (JIs)/inseto, e o produto químico padrão, tiametoxam, foram testados. Em um segundo experimento, a bactéria Photorhabdus luminescens (Thomas e Poinar, 1979), Xenorhabdus szentirmaii Lengyel, 2005 e Xenorhabdus nematophila (Poinar e Thomas, 1965) (Enterobacterales: Morganellaceae) em 3,0 x 109 células/ml foram avaliadas para cada tratamento. Dez repetições foram estabelecidas, cada uma contendo dez fêmeas/cochonilhas dentro de uma placa de Petri de 10 cm, totalizando 100 indivíduos/tratamento. Todos os tratamentos foram mantidos em condições estáveis (25±1 ºC, U 70±10%, no escuro). Todas as espécies de nematoides infectaram S. sacchari. Steinerma rarum (PAM25) proporcionou a maior mortalidade contra a cochonilha rosada da cana-de-açúcar (79,25%), seguida por H. bacteriophora (HB EN01) (58,25%) e S. carpocapsae (All) (42,50%) (P<0,001). As taxas de mortalidade causada por X. szentirmaii, P. luminescens e X. nematophila foram de 40, 45 e 20%, respectivamente. Steinerma rarum (PAM25) tem condições de ser um agente potencial a ser incorporado ao manejo integrado de pragas da cana-de-açúcar.

Abstract Sugarcane crops Saccharum spp. (Poales: Poaceae) produces different derivatives to the world: sugar, ethanol and bioenergy. Despite the application of pesticides, insect pests still cause economic losses, among these the pink sugarcane mealybug Saccharicoccus sacchari (Cockerell, 1895) (Hemiptera: Pseudococcidae) causing direct and indirect damage to the plant. This study assess the virulence of three entomopathogenic nematodes (EPNs) species and their symbiont bacteria against the pink sugarcane mealybug, under laboratory conditions. Fourteen treatments represented by control (distilled water), Heterorhabditis bacteriophora Poinar, 1976 (HB EN01) (Rhabditida: Heterorhabditidae), Steinernema rarum (Doucet, 1986) (PAM25) and Steinernema carpocapsae Weiser, 1955 (All) (Rhabditida: Steinermatidae) at concentrations of 25, 50, 75 and 100 infective juveniles (IJs)/insect, and the standard chemical product, thiamethoxam, were assayed. In a second experiment, the bacteria Photorhabdus luminescens (Thomas and Poinar, 1979), Xenorhabdus szentirmaii Lengyel, 2005 and Xenorhabdus nematophila (Poinar and Thomas, 1965) (Enterobacterales: Morganellaceae) at 3.0 x 109 cells/ml were assessed for each treatment. Ten replications were stablished, each one counting ten females/mealybugs inside a 10 cm Petri dish, amounting 100 individuals/treatment. All treatments were kept under stable conditions (25±1 ºC, H 70±10%, in the dark). All nematodes species infected S. sacchari. Steinerma rarum (PAM25) provided the highest mortality against the pink sugarcane mealybug (79.25%), followed by H. bacteriophora (HB EN01) (58.25%) and S. carpocapsae (All) (42.50%) (P<0.001). The mortality rate caused by X. szentirmaii, P. luminescens and X. nematophila were 40, 45 and 20%, respectively. Steinerma rarum (PAM25) has conditions to be a potential agent to be incorporate into the integrated pest management in sugarcane.

Resumo A leishmaniose visceral é uma doença tropical negligenciada. Foram avaliadas a distribuição espacial dos casos de leishmaniose visceral no estado de Alagoas. Todos os casos de LV, registrados pela secretaria de saúde, foram analisados e georreferenciados. Entre 2008 e 2017, 97,1% dos municípios apresentaram classificação esporádica de transmissão. Com a evolução temporal, a incidência de casos de leishmaniose visceral se concentrou na maioria dos municípios da microrregião de Santana do Ipanema-AL. A análise espaço-tempo, se considerada, pode promover o aprimoramento das ações de vigilância e controle da leishmaniose visceral.

Abstract Visceral leishmaniosis is a neglected tropical disease. We evaluated the spatial distribution of cases of visceral leishmaniosis in the state of Alagoas, Brazil. All cases of VL, registered by the health department, were analyzed and georeferenced. Results: Between 2008 and 2017, 97.1% of the municipalities presented sporadic classification of transmission. With temporal evolution, the incidence of cases of visceral leishmaniosis was concentrated in most municipalities in the microregion of Santana do Ipanema-AL. Space-time analysis, if considered, may promote the improvement of surveillance and control actions of visceral leishmaniosis.

Leachate from a composting plant was characterized and applied as a biofertilizer in lettuce crops. Characteristics of untreated (UE) and anaerobically treated (TE) leachate samples were compared. The pH of TE (8.2) increased in relation to the UE (5.2) due to an increase in ammonia nitrogen in TE (1197 mg L-1) compared to UE (859 mg L-1). Anaerobic treatment was efficient in the removal of organic matter from the leachate, evaluated by the decrease of dissolved organic carbon, biochemical oxygen demand, total organic carbon and total solids. K presented the highest concentration (1743 mg L-1) in TE, followed by Mg (135 mg L-1). Cd, Pb and Cr were present at low concentrations in the samples, 0.047, 0.206 and 0.081 mg L-1, respectively. Salmonella, thermotolerant coliforms and viable helminth eggs were not present in TE, which was applied as a biofertilizer in a lettuce crop and compared to mineral fertilization based on fresh matter and dry matter production. Lettuce production using TE was statistically equivalent to mineral fertilization. Toxic metals were not detected in the lettuce shoots. It was concluded that the anaerobically treated leachate from the composting company has the potential to be used as a biofertilizer.

Abstract It is described for the first time the synthesis and characterization of NiMn2O4 employing the Mn ores from the Amazon Region as starting material, instead of using commercial reagents as normally occurs in its synthesis process. Initially, an Mn ore was transformed into a single product, the octahedral layer (OL) manganese oxide with Ni2+ ions interlayer (Ni-OL-2), which was used as a matrix to obtain NiMn2O4 by thermal decomposition. The following techniques were used for characterization: X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), infrared spectroscopy (FTIR), thermal analysis (TG-DTA), scanning (SEM) and transmission (TEM) electron microscopies. The results revealed that Mn oxide ore composed of nsutite mineral transformed into a well-ordered crystalline Ni-OL-2 phase, after the hydrothermal and cation exchange process. The thermal decomposition of Ni-OL-2 produced the nickel manganite phase at 850 °C with spherical ball morphology and crystal sizes in the range of 200-300 nm.

In this work, cellulose-based composite biofilms doped with silver nanoparticles (AgNPs) have been produced by eco-friendly process. The AgNPs were synthesized from Ilex paraguariensis with an average size of 45 nm, a characteristic plasmon band at 450 nm and zeta potential of -23 mV. The biofilm has been synthesized by casting method, using different volumes of AgNPs suspension with glycerol plasticizing agent (T6-T10) or not (T1-T5). The AgNPs were successfully incorporated into the biofilms, which was confirmed by scanning electron microscopy. The mechanical and optical structural and the antimicrobial properties of the biofilms have been determined. In the presence of AgNPs, the mechanical properties, thermal stability and water vapor barrier of the biofilms have not been altered. However, the addition of glycerol decreased the tensile strength and the modulus of elasticity, in addition to increasing the elongation of the biofilms and the water vapor barrier. The biofilm T10 showed a transmittance of ca. 10%, with high potential to be used as a UV light blocker. Finally, the biofilms doped with AgNPs showed activity against the bacterium Pseudomonas fluorescens. Given the above, this work presented a new biofilm with activity against the bacterium Pseudomonus fluorescens obtained by eco-friendly process.

Abstract Due to the vast area of application and reliability, fiber optic magnetic field sensors have been the subject of several studies, however, some of these application areas are submitted to temperature variations, which can hinder the sensors in monitoring the magnetic field. With this panorama, this work analyzes through computational modeling a fiber optical magnetic field sensor, using the magneto-optical Faraday effect and observing temperature effects in the sensor response. For modeling, a numerical model built in COMSOL Multiphysics is used. The results show a value for cross-sensitivity of 3.27 mT/°C in a non-optimized configuration of the sensor and of 2.47 mT/°C for an optimized configuration. A methodology for optimizing the sensor to operate in a certain temperature range, 55 to 75 °C, is also discussed. The results presented in this work show that the temperature is an important factor to be considered to improve the selectivity and to obtain the correct sensitivity of the sensor.

RESUMO Espécies silvestres de maracujazeiro, devido à maior tolerância aos estresses ambientais, revelam potencial como porta-enxerto interespecífico, P. foetida é uma espécie silvestre potencialmente tolerante à salinidade. Portanto, o objetivo com a pesquisa foi avaliar os efeitos da salinidade da água de irrigação no crescimento de porta-enxertos de maracujazeiro-bravo (P. foetida L.). O experimento foi realizado em ambiente protegido. Os tratamentos consistiram na condutividade elétrica da água de irrigação (0,3; 1,0; 2,0; 3,0 e 4,0 dS m-1), distribuídos em blocos casualizados. As avaliações foram realizadas aos 7, 14, 21, 28 e 35 dias após o transplantio e consistiram em: altura e diâmetro do caule, número de folhas, tamanho médio da folha, área foliar, massas das matérias secas da parte aérea, das raízes e total. Nos porta-enxertos jovens, os efeitos deletérios da salinidade sobre o crescimento em altura e os componentes foliares foram observados sob menores condutividades elétricas, sendo a tolerância aumentada com a acréscimo da idade. Entretanto, o acúmulo de biomassa seca foi restringido com maior severidade pela salinidade com o aumento da idade dos porta-enxertos. Os porta-enxertos de P. foetida são tolerantes à salinidade e podem ser irrigados com água de até 4,0 dS m-1.

ABSTRACT Wild passion fruit species, due to the greater tolerance to environmental stresses, reveal potential as interspecific rootstocks. Passiflora foetida is a wild species potentially tolerant to salinity. Therefore, the objective with the study was to evaluate the effects of irrigation water salinity on the growth of wild passion fruit (P. foetida L.) rootstocks. The experiment was carried out in a protected environment. The treatments consisted of the electrical conductivity of the irrigation water (0.3; 1.0; 2.0; 3.0 and 4.0 dS m-1), distributed in randomized blocks. The assessments were performed at 7, 14, 21, 28 and 35 days after transplanting and consisted of: stem height and diameter, number of leaves, average leaf size, leaf area, and dry matter of shoots, roots and total. In younger rootstocks, the deleterious effects of salinity on height growth and leaf components were observed under lower electrical conductivities, with tolerance increasing with age. However, dry biomass accumulation was more severely restricted by salinity with increasing rootstock age. P. foetida rootstocks are salinity tolerant and can be irrigated with water of up to 4.0 dS m-1.

Abstract Bacteria may be the initial cause of certain pathologies as well as a secondary agent responsible for the development of complications such as pressure ulcer infections. Pressure ulcers are a persistent health problem, especially in immunocompromised patients, and associated with infection by opportunistic microorganisms with antimicrobial resistance, such as Klebsiella pneumoniae, highlight the need for the development of new antimicrobial approaches. Thus, the aim of this study was to evaluate the antibacterial and anti-adherent activity of Origanum vulgare L. (oregano) essential oil against Klebsiella pneumoniae strains, as well as the effect of its association with synthetic antimicrobials. To this end, the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) analyses were performed on microdilution plates. The assay of the Minimum Inhibitory Adherence Concentration (MIAC), with test tubes. As well as, the association study through the infusion disc method containing ampicillin (AMP), gentamicin (GEN), ciprofloxacin (CIP) and ceftriaxone (CEF). Therefore, it was possible to obtain that the essential oil of oregano presents antimicrobial and bactericidal activity, with MIC ranging between 128μg/mL and 256 μg/mL and MBC between 256 μg/mL and 512 μg/mL, on the tested K. pneumoniae strains. When used in association with ampicillin and gentamicin, oregano essential oil showed synergistic effect for some strains. Therefore, it is observed that the tested essential oil can act as a promising antibacterial in the treatment of diseases caused by K. pneumoniae.

Resumo As bactérias podem ser a causa inicial de determinadas patologias como também um agente secundário responsável pelo desenvolvimento de complicações como as infecções das lesões por pressão. As lesões por pressão configuram um problema de saúde persistente, principalmente em pacientes imunocomprometidos, e associadas a infecção por microrganismos oportunistas com resistência antimicrobiana, como por exemplo a Klebisiella pneumoniae, ressaltam a necessidade do desenvolvimento de novas abordagens antimicrobianas. Assim, o objetivo deste estudo foi avaliar a atividade antibacteriana e antiaderente do óleo essencial de Origanum vulgareL. (orégano) contra cepas da Klebisiella pneumoniae, bem como o efeito da sua associação com antimicrobianos sintéticos. Para isso foram realizadas as análises da Concentração Mínima Inibitória (CIM) e Concentração Bactericida Mínima (CBM) em placas de micro diluição. O ensaio da Concentração Mínima de Aderência (CIMA), com tubos de ensaio. Como também, o estudo de associação através do método de disco de infusão contendo ampicilina, gentamicina, ciprofloxacino e ceftriaxona. Assim sendo, foi possível obter que o óleo essencial de orégano apresenta atividade antimicrobiana e bactericida, com CIM variando entre 128μg/mL e 256 μg/mL e CBM entre 256 μg/mL e 512 μg/mL, sobre as cepas de K. pneumoniae testadas. Quando utilizado em associação com a ampicilina e gentamicina, o óleo essencial de orégano demonstrou efeito sinérgico para algumas cepas. Portanto, observa-se que o óleo essencial testado pode atuar como um promissor antibacteriano no tratamento de doenças causadas por K. pneumoniae.

Abstract Water stress limits the initial growth and development of maize mass and grain, as well as the physiological process for absorbing the amount of mineral elements. The objective was to evaluate the effect of silicon on germination and growth of corn seedlings submitted to water deficit. The experiment was carried out in the laboratory and the experimental design was completely randomized (factorial 3 × 4), with three concentrations of calcium silicate (0.0; 1.0 and 2.0 mM) and 4 solutions of PEG-6000 to simulate different osmotic potentials (0, 0; -0.3; -0.6; -0.9 MPa). Germination percentage, germination speed index (GSI), mean germination time (MGT), percentage of non-germinated and abnormal germinated, length and dry matter of shoot, root and total seedlings were evaluated. Water deficiency reduced the parameters TG, GSI and MGT. The water deficit reduce the MSPA, MSR and MST with more than 80% reduction in mass from seedlings without deficiency to seedlings with deficiency. For CPA, CR and CT there was a reduction of at least 87%, 70% and 77%, respectively, among seeds without deficiency compared to seeds submitted to deficiency. The use of silicon in corn seeds did not attenuate the stress caused by water deficit simulated by PEG-6000.

Resumo O estresse hídrico limita o crescimento inicial e o desenvolvimento da massa e do grão de milho, assim como no processo fisiológico para a absorção da quantidade de elementos minerais. Objetivou-se avaliar o efeito do silício na germinação e no crescimento de plântulas de milho submetidas a deficiência hídrica. O experimento foi desenvolvido em laboratório e o delineamento experimental foi inteiramente casualizado (DIC) (fatorial 3 × 4), sendo três concentrações de Silicato de cálcio (0,0; 1,0 e 2,0 mM) e 4 soluções de PEG-6000 a simular diferentes potenciais osmóticos (0,0; -0,3; -0,6; -0,9 MPa). Foram avaliados a porcentagem de germinação, o índice de velocidade de germinação (IVG), o tempo médio de germinação (TMG), a porcentagem de não germinadas e de germinadas anormais, o comprimento e matéria seca da parte aérea, raiz e total das plântulas. A deficiência hídrica diminuiu os parâmetros TG, IVG e TMG. O déficit hídrico reduz a MSPA, MSR e MST com mais de 80% de redução da massa das plântulas sem deficiência para as plântulas com deficiência. Para CPA, CR e CT houve redução de, no mínimo, 87%, 70% e 77%, respectivamente entre as sementes sem deficiência em comparação as sementes submetidas a deficiência. A utilização de silício em sementes de milho não atenuou o estresse causado pela deficiência hídrica simulada por PEG-6000.

Abstract Plant-induced resistance can be an important component of soybean mites biological control programs. This work evaluates the preference of predatory mite Neoseiulus californicus (Acari: Phytoseiidae) to soybean plants under single and multiple herbivory conditions by two-spotted spider mite Tetranychus urticae (Acari: Tetranychidae), and velvetbean caterpillar Anticarsia gemmatalis (Lepidoptera: Noctuidae). Using a Y olfactometer, the following scenarios were evaluated: soybean with no infestation and soybean infested with A. gemmatalis; soybean infested with T. urticae and A. gemmatalis, and soybean infested with T. urticae and with both T. urticae and A. gemmatalis. Volatile compounds released by plants were analyzed and identified by a Trace GC Ultra gas chromatograph coupled to a mass spectrometer with a solid phase micro-extraction ion-trap. The predatory mite N. californicus preferred soybean plants infested with T. urticae compared to those infested with A. gemmatalis. Multiple infestation did not interfere with its preference to T. urticae. Multiple herbivory of T. urticae and A. gemmatalis modified the chemical profile of volatile compounds emitted by soybean plants. However, it did not interfere with the search behavior of N. californicus. Out of the 29 identified compounds only five promoted predatory mite response. Thus, regardless of single or multiple herbivory by T. urticae with or without A. gemmatalis, the indirect induced resistance mechanisms operate similarly. As such, this mechanism contributes to an increase in the encounter rate between predator and prey for N. Californicus and T. urticae, and the efficacy of biological control of mites on soybean.

Resumo A resistência induzida por plantas pode ser um importante componente dos programas de controle biológico de ácaros da soja. Este trabalho avalia a preferência do ácaro predador Neoseiulus californicus (Acari: Phytoseiidae) às plantas de soja sob condições de herbivoria simples e múltipla pelo ácaro-rajado Tetranychus urticae (Acari: Tetranychidae) e pela lagarta-da-soja Anticarsia gemmatalis (Lepidoptera: Noctuidae). Utilizando o olfatômetro Y, foram avaliados os seguintes cenários: soja sem infestação e soja infestada com A. gemmatalis; soja infestada com T. urticae e A. gemmatalis, e soja infestada com T. urticae e com T. urticae e A. gemmatalis. Os compostos voláteis liberados pelas plantas foram analisados e identificados por um cromatógrafo gasoso Trace GC Ultra acoplado a um espectrômetro de massas com uma armadilha de íons de microextração em fase sólida. O ácaro predador N. californicus preferiu plantas de soja infestadas com T. urticae em relação àquelas infestadas com A. gemmatalis. A infestação múltipla não interferiu na preferência por T. urticae. A herbivoria múltipla de T. urticae e A. gemmatalis modificou o perfil químico de compostos voláteis emitidos por plantas de soja. No entanto, não interferiu no comportamento de busca de N. californicus. Dos 29 compostos identificados apenas cinco promoveram resposta de ácaros predadores. Assim, independentemente da herbivoria simples ou múltipla por T. urticae com ou sem A. gemmatalis, os mecanismos de resistência induzida indiretamente operam de forma semelhante. Assim, esse mecanismo biológico contribui para o aumento da taxa de encontro entre predador e presa para N. Californicus e T. urticae, e para a eficácia do controle de ácaros em soja.

The aerospace industry is constantly looking for innovative materials that exhibit good mechanical and corrosion properties. The 2198-T851 (Al-Cu-Li) alloy was developed to replace the conventional Al-Cu-Mg in aircraft structures. Despite the usefulness of the 2198-T851 alloy, its performance may be affected when subjected to an aggressive medium containing chloride ions. The deposition of Nb2O5 coatings by using the reactive sputtering technique on the 2198-T851 alloy surface appears as a powerful tool to improve the corrosion resistance of this material. Recently, groundbreaking research findings have demonstrated the positive effect of Nb2O5 coatings on corrosion protection of alloy 2198-T851. However, the corrosion products originated from the 2198-T851 aluminium alloy are poorly understood. The use of Raman spectroscopy and XPS techniques may help to shed some light on the corrosion products of 2198-T851 alloy. Results demonstrated the corrosion products are mainly composed by CuCl2 x H2O, CuCl, Cu2Cl(OH)3, Al(OH)3, and AlO(OH).

In this work, silver nanoparticles (AgNPs) obtained from photographic waste were synthesized and electrodeposited via cyclic voltammetry using epoxy-graphite composite as an electrochemical substrate. Both electrodes, unmodified (Epoxy/C) and modified (Epoxy/C/AgNPs), were characterized electrochemically by electrochemical impedance spectroscopy (EIS), charge transfer constant (K0), and electroactive area. The modified electrode provided lower charge transfer resistance (275 Ω), more kinetically favored electron transfer (K0 = 1.15 × 10-3 cm s-1), and a 1.7-fold increase in the active area compared to the unmodified electrode. Additional characterizations by scanning electron microscopy (SEM) and Raman spectroscopy confirmed the presence of AgNPs structures on the carbonaceous surface. As a proof of concept, Pb2+ was used as a model analyte, and a square wave anodic stripping voltammetry (SWASV) method was developed to evaluate the analytical performance of both electrodes. A wider linear range (4.0 to 40.0 µg L-1), the appropriate limit of detection (1.2 µg L-1), and a 6-fold increase in sensitivity were found using the modified electrode, suggesting that the AgNPs significantly contributed to the performance of the electrode. The proposed method was applied to three real water samples, where the Pb2+ levels varied from 11.3 to 19.5 µg L-1. The proposed protocol (reuse of silver waste) has proven to be a powerful tool for improving the detection of Pb2+, which can be helpful for other electrochemical sensing applications in locations with minimal infrastructure.