993 resultados para G.1.6 Optimization
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Ulla Salmelaisen väitöskirja Tiedon välittyminen ja rakentuminen kuntoutuksessa : moniammatillinen asiantuntijayhteistyö ikäihmisten laitosmuotoisessa kuntoutuksessa (Turun yliopisto 2008).
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Phoma leaf spot, caused by Phoma costarricensis poses a serious threat to coffee (Coffea arabica) production, especially in the highlands of the state of Minas Gerais, Brazil. Extracts of citric biomass, coffee berry husks and coffee leaves severely affected by rust caused by Hemileia vastatrix, were evaluated against P. costarricensis. In an in vitro assay, aqueous extracts of rusted leaves and berry husks plus the commercial extracts based on citric biomass named Ecolife® and Agromil® were tested at various dilutions on the mycelial growth inhibition of P. costarricensis. In vivo, coffee seedlings maintained in glasshouse, were sprayed with these extracts seven days before inoculation of P. costarricensis. Only extracts from citric biomass had inhibitory effects on the fungus. In vivo, Ecolife® (5 ml/l), Agromil® (5 g/l) and the aqueous extract of rusted coffee leaves (dilution 1:6) reduced Phoma leaf spot. Both, Ecolife® and the extract of rusted coffee leaves were significantly more effective in reducing the area under the lesion progress curve when applied at lower doses, indicating a possible effect on the induction of resistance.
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A capacidade de Acidovorax avenae subsp. citrulli sobreviver epifítica e endofíticamente nas folhas e raízes, bem como na rizosfera de meloeiro, foi determinada utilizando um isolado mutante resistente a rifampicina (Aac1Rif). Folhas de meloeiros com 18 dias, cultivados em casa de vegetação e no campo, foram pulverizadas com suspensões do mutante nas concentrações (3,4 x 10², 3,4 x 10³ e 3,4 x 10(4) ufc.ml-1). Para determinar a sobrevivência em raízes e na rizosfera sementes de melão Amarelo híbrido AF-682 foram semeadas em solo infestado com suspensões de Aac1Rif a 3,4 x 10(5), 3,4 x 10(6) e 3,4 x 10(7) ufc.ml-1. A cada seis dias, amostras de folhas, raízes e solo rizosférico foram coletadas e processadas para isolamento em meio de ágar nutritivo + extrato de levedura + dextrose contendo rifampicina. As populações bacterianas foram determinadas em ufc.g-1 de amostra e os dados obtidos transformados em log10 para análise de regressão. Nas folhas de meloeiro, em casa-de-vegetação e campo, o mutante Aac1Rif sobreviveu epifiticamente durante 54 dias, observando-se inicialmente aumento da população bacteriana epifítica, com posterior declínio, sendo as populações finais semelhantes nas duas condições estudadas, com valores variando de 10³ a 10(4) ufc.g-1 de folha, independente da concentração do inóculo inicial. Nas raízes e rizosfera, em casa-de-vegetação, a população bacteriana decresceu ao longo do tempo até atingir aos 60 dias após a infestação do solo, níveis de 10² a 10³ ufc.g-1 de raiz e 10¹ ufc.g-1 de solo. AacRif não foi detectado sobrevivendo endofiticamente em folhas ou raízes de meloeiro.
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Southern blight (Sclerotium rolfsii) of soybean (Glycine max) is an important disease throughout the world. Some soil amendments can reduce disease levels by improving soil microbial activity. The main goals of this study were to investigate the effects of soil amendments such as dried powders of kudzu (Pueraria lobata), velvetbean (Mucuna deeringiana), and pine bark (Pinus taeda), on soil microbial population and disease caused by S. rolfsii on soybean. Pine bark, velvetbean (mucuna) and kudzu (25 g kg-1) added to soil were effective in reducing disease incidence [non-amended (NA) ~ 39%; amended (A) ~ 2 to 11%)]. Bacillus megaterium was the bacteria most frequently isolated in soils with velvetbean or kudzu (NA ~ log 5.7 CFU g-1 of dried soil; A ~ log 6.2). Soils with velvetbean and kudzu stimulated increase in population of Enterobacter aerogenes (NA ~ log 3; A ~ log 5.1-5.8). Pseudomonas putida population was higher in A than in NA (NA ~ log 4; A ~ log 5.5), and was negatively correlated (r = -0.83, P = 1%) to disease incidence. Soil amended with kudzu and pine bark stimulated increases in populations of Trichoderma koningii (NA ~ log 1.6; A ~ log 2.9) and Penicillium citreonigrum (NA ~ log 1.3; A ~ log 2.6), respectively. Penicillium herquei soil population increased with addition of kudzu (NA ~ log 1.2; A, ~ log 2.5). These microorganisms are antagonists of soil-borne pathogens. Powders of velvetbean, kudzu, and pine bark can increase antagonistic population in soil and reduce disease.
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O colapso do meloeiro (Cucumis melo), causado por Monosporascus cannonballus, é uma das principais enfermidades que acometem esta olerícola. O presente trabalho objetivou estudar o potencial do controle biológico de M. cannonballus com Chaetomium. Substrato infestado com 0,5; 1; 2; 4 e 8 x 10(5) UFC g-1 de Chaetomium foi colocado em bandejas, nas quais sementes de meloeiro do tipo Pele de Sapo cv. PS 1430 foram semeadas após duas semanas de incubação. As mudas obtidas foram transplantadas para vasos com substrato semelhante, sendo que neste momento o substrato foi infestado com mais 2,5 x 10(4) UFC g-1 de Chaetomium por vaso e 20 UFC g-1 de substrato de M. cannonballus. Três testemunhas foram utilizadas, uma infestada apenas com Chaetomium, outra somente com M. cannonballus e testemunha absoluta. O delineamento estatístico foi inteiramente casualizado com cinco repetições. As avaliações foram efetuadas aos 45 dias após o transplante, sendo calculado o índice geral de doença e o percentual de controle. O valor do índice geral de doença variou conforme o aumento da concentração de Chaetomium, sendo os menores valores encontrados para os tratamentos 4 e 8 x 10(5) UFC g-1de Chaetomium equivalentes a 0,9 e 0,6, respectivamente. A análise estatística demonstrou que os tratamentos correspondentes a 4 e 8 x 10(5) UFC g-1 de Chaetomium foram mais eficientes, diferindo dos demais, com percentual de controle superior a 55 %, evidenciado o potencial de Chaetomium no controle de M. cannonballus.
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O método clássico iodimétrico foi utilizado para determinação de ácido ascórbico (AA) nos frutos araçá (Eugenia sp.), acerola (Malphigia sp.) e laranja (Citrus sinenses). Os frutos coletados foram classificados como verdes, verde- amarelados ou amarelos conforme a cor superficial. Os frutos foram levados ao laboratório e resfriados para minimizar a oxidação de AA. Os teores determinados de AA para o araçá evidenciaram que há uma gradiente de concentração entre as partes superior e inferior dos frutos, sendo a concentração em C2 (concentração de ácido ascórbico na parte inferior do fruto) sempre maior que a concentração em C1 (concentração de ácido ascórbico na parte superior do fruto ligada ao pedúnculo). Comportamento semelhante também foi observado para acerolas e laranjas, que apresentaram uma concentração média na parte superior de 17,7 mg g-1 e 0,612 mg L-1 e na parte inferior 19,6 mg g-1 e 0,665 mg L-1, respectivamente. Pelos resultados obtidos pode-se concluir que os três frutos apresentam uma distribuição heterogênea de AA e essa variação é mais pronunciada para frutos verdes, i.e. frutos menos adequados para consumo.
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A method has been developed for the simultaneous determination of Cd and Pb in antibiotics used in sugar-cane fermentation by GFAAS. The integrated platform of transversely heated graphite atomizer was treated with tungsten to form a coating of tungsten carbide. Six samples of commercial solid antibiotics were analyzed by injecting 20 µL of digested samples into the pretreated graphite platform with co-injection of 5 µL of 1000 mg L-1 Pd as chemical modifier. Samples were mineralized in a closed-vessel microwave-assisted acid-digestion system using nitric acid plus hydrogen peroxide. The pyrolysis and atomization temperatures of the heating program of the atomizer were selected as 600°C and 2200°C, respectively. The calculated characteristic mass for Cd and Pb was 1.6 pg and 42 pg, respectively. Limits of detection (LOD) based on integrated absorbance were 0.02 µg L-1 Cd and 0.7 µg L-1 Pb and the relative standard deviations (n = 10) for Cd and Pb were 5.7% and 8.0%, respectively. The recoveries of Cd and Pb added to the digested samples varied from 91% to 125% (Cd) and 80% to 112% (Pb).
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An activated carbon was obtained by chemical activation with phosphoric acid, CM, from a mineral carbon. Afterwards, the carbon was modified with 2 and 5 molL-1, CMox2 and CMox5 nitric acid solutions to increase the surface acid group contents. Immersion enthalpy at pH 4 values and Pb2+ adsorption isotherms were determined by immersing activated carbons in aqueous solution. The surface area values of the adsorbents and total pore volume were approximately 560 m².g-1 and 0.36 cm³g-1, respectively. As regards chemical characteristics, activated carbons had higher acid sites content, 0.92-2.42 meq g-1, than basic sites, 0.63-0.12 meq g-1. pH values were between 7.4 and 4.5 at the point of zero charge, pH PZC. The adsorbed quantity of Pb2+ and the immersion enthalpy in solution of different pH values for CM activated carbon showed that the values are the highest for pH 4, 15.7 mgg-1 and 27.6 Jg-1 respectively. Pb2+ adsorption isotherms and immersion enthalpy were determined for modified activated carbons and the highest values were obtained for the activated carbon that showed the highest content of total acid sites on the surface.
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O propósito deste trabalho foi determinar os parâmetros cinéticos de decomposição térmica para uma amostra de propelente base simples e base dupla. Os dados obtidos pela calorimetria exploratória diferencial foram ajustados para o modelo cinético de pseudo-primeira ordem de Flynn, Wall e Ozawa. Os respectivos parâmetros obtidos foram: BS REX 1200 (Ea) (2,3 ± 0,2) 10² kJ mol-1 e (A) 1,34 10(25) min-1; BD-111 (Ea) (1,6 ± 0,1) 10² kJ mol-1 e (A) 3,31 10(17) min-1. O espectro de infravermelho da amostra de propelente base dupla indicou a presença de salicilato, justificando o comportamento de decomposição observado na respectiva curva térmica.
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Highly sensitive and selective spectrophotometric methods (A and B) were developed for the determination of micro amounts of olanzapine (OLZ). Method A (direct method) is based on the oxidation of olanzapine with a known excess of iodine monochloride (ICl) in an acidic medium. Under the same condition, thymol blue was iodinated by unreacted ICl, and the absorbance of uniodinated thymol blue was measured at 536 nm. The decrease in ICl concentration is a measure of drug concentration. In method B (indirect method), oxidation of OLZ by a known excess of Ce(IV) in sulfuric acid medium followed by the reaction of unreacted Ce(IV) with leuco crystal violet (LCV) to crystal violet (CV), which is measured in an acetate buffer medium ( pH 4.9) at 580 nm. These methods obey the Beer's law in the concentration range of 0.2-1.6 µg mL-1 (method A) and 0.1-1.4 µg mL-1 (method B). The developed procedures have been successfully applied to the determination of OLZ in pure and in dosage forms. The results exhibit no interference from the presence of excipients. The reliability of the methods was established by parallel determination of OLZ against the reference method.
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The current study aims to verify the best method for a rapid and efficient extraction of flavonoids from Alpinia zerumbet. Dried leaves were extracted using distillated water and ethanol 70% by extraction methods of shaking maceration, ultrasonic, microwave and stirring. By the application of TLC and reversed-phase HPLC techniques the rutin and kaempferol-3-O-glucuronide were detected. Ethanol 70% was more efficient for flavonoids extraction than water. No significant yielding variation was verified for ultrasonic, microwave and stirring methods using ethanol 70% (11 to 14%). The relative concentration of rutin and kaempferol-3-O-glucuronide, respectively, was higher by ultrasonic (1.5 and 5.62 mg g-1 dried leaves, respectively) and by microwave (1.0 and 6.64 mg g-1 dried leaves) methods using ethanol. Rapid and simplified extraction proceeding optimize phytochemical work and acquisition of secondary metabolites.
Flavonoids extraction from Alpinia zerumbet (Pers.) Burtt et Smith leaves using different procedures
Resumo:
The current study aims to verify the best method for a rapid and efficient extraction of flavonoids from Alpinia zerumbet. Dried leaves were extracted using distillated water and ethanol 70% by extraction methods of shaking maceration, ultrasonic, microwave and stirring. By the application of TLC and reversed-phase HPLC techniques the rutin and kaempferol-3-O-glucuronide were detected. Ethanol 70% was more efficient for flavonoids extraction than water. No significant yielding variation was verified for ultrasonic, microwave and stirring methods using ethanol 70% (11 to 14%). Relative concentration of rutin and kaempferol-3-O-glucuronide, respectively, was higher by ultrasonic (1.5 and 5.62 mg g-1 dried leaves) and by microwave (1.0 and 6.64 mg g-1 dried leaves) methods using 70% ethanol. Rapid and simplified extraction proceeding optimize phytochemical work and acquisition of secondary metabolites.
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The structures of the principal oligosaccharides in the honeydew exudate of the sorghum ergot pathogen Claviceps africana, which has become epidemic in the Americas, have been characterized through linkage analysis using FAB-MS and GC-MS techniques, as 1,6-di-b-D-fructofuranosyl-D-mannitol and 1,5-di-b-D-fructofuranosyl-D-arabitol trisaccharides, 1-b-D-fructofuranosyl-D-mannitol and 5-b-D-fructofuranosyl-D-arabitol disaccharides and other minor disaccharides and trisaccharides. Their structural diversity is explained according to perceived biosynthetic interrelationships in pathways that appear to be unique amongst ergot fungi, particularly concerning intra-molecular reduction of fructose. The oligosaccharide, 1,6-di-b-D-fructofuranosyl-D-mannitol, which inhibits C. africana macrospore germination at a concentration in water of 1 g/mL or more, forms together with other slightly less bioactive oligosaccharides, the basis of a novel strategy to limit ergot disease losses in hybrid sorghum seed production.
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Trinta e seis (36) cultivares de milho foram avaliadas em relação à incidência de grãos ardidos, mofados e produção de fumonisina B1. Amostras de 1,2 kg de grãos foram analisadas visualmente para a quantificação de grãos ardidos (Fusarium subglutinans), mofados (Penicillium oxalicum) e para a análise de fumonisina B1. Os grãos ardidos foram submetidos à análise de sanidade (papel de filtro com congelamento) visando identificar os fungos a eles associados. A cultivar Hatã 3052 apresentou 7,6% de grãos ardidos, ultrapassando o limite de tolerância que é de 6,0%. As cultivares AG 5011, HT 7105-3, Dina 1000 e C 701 apresentaram 16,8% , 3,4%, 3,2% e 3,1% de grãos mofados, respectivamente, acima do limite de tolerância que é de 3,0%. O fungo Fusarium subglutinans (Gibberella fujikuroi var. subglutinans) foi o causador de grãos ardidos, cuja detecção variou de 50,0 a 99,0%. A análise de variância mostrou diferenças significativas entre as cultivares com relação às incidências de grãos ardidos e de grãos mofados. Com relação à produção de fumonisina B1, as cultivares Hatã 3052, NB 6077 e 983 P produziram 7,0; 6,1 e 5,9 µg.g-1 de grãos, respectivamente, diferindo significativamente da cultivar P3071 (2,2 µg.g-1 de grãos). Conclui-se que há diferenças significativas entre as cultivares de milho em relação à produção de grãos ardidos e mofados, bem como acentuada interação entre as cultivares e o fungo toxigênico Fusarium subglutinans (Gibberella fujikuroi var. subglutinans) quanto à biossíntese de fumonisina B1 em grãos de milho.
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Previous studies have demonstrated that volatile organic compounds (VOCs), produced by the yeast Saccharomyces cerevisiae, were able to inhibit the development of phytopathogenic fungi. In this context, the nematicidal potential of the synthetic mixture of VOCs, constituted of alcohols and esters, was evaluated for the control of the root-knot nematode Meloidogyne javanica, which causes losses to crops of high economic value. The fumigation of substrate containing second-stage juveniles with VOCs exhibited nematicidal effect higher than 30% for the lowest concentration tested (33.3 µL g-1 substrate), whereas at 66.6 and 133.3 µL g-1 substrate, the nematode mortality was 100%. The present results stimulate other studies on VOCs for nematode management.