Análises de fluorescência e consumo de água em Brachiaria decumbens após aplicação de herbicidas em pós-emergência

A análise da fluorescência da clorofila vem sendo largamente utilizada no entendimento dos mecanismos da fotossíntese propriamente dito, bem como na avaliação da capacidade fotossintética alterada com a aplicação de herbicidas. O consumo de água pelas plantas é uma maneira também de avaliar a atuação dos herbicidas nas plantas daninhas. O objetivo deste trabalho foi avaliar a fluorescência através da taxa de transporte de elétrons, consumo de água e fitointoxicação de Brachiaria decumbens após aplicação de quatro herbicidas de diferentes mecanismos de ação. Aos 30 dias após a semeadura de B. decumbens, as plantas foram arrancadas dos tubetes e preparadas para os tratamentos. Elas tiveram o sistema radicular colocado em tubos falcon preenchidos com água, e a superfície dos falcon foi isolada com papel-alumínio, para evitar evaporação do sistema. Os herbicidas aplicados foram: glyphosate, haloxyfop-methyl, diuron e amicarbazone. A aplicação foi feita com um pulverizador estacionário instalado em laboratório; após a aplicação dos tratamentos, as plantas foram mantidas em casa de vegetação. Foi avaliada a taxa de transporte de elétrons (ETR), o consumo de água e a fitointoxicação das plantas em vários períodos após o início do experimento. Os dados de ETR e fitointoxicação foram expressos em porcentagem da testemunha e submetidos à análise de variância e à comparação das médias. Para o consumo de água, os dados foram acumulados e ajustados por modelos de regressão. Assim, pode-se dizer que as plantas de B. decumbens tiveram respostas diferentes aos herbicidas aplicados, e o consumo de água das plantas está relacionado diretamente com o transporte de elétrons. A metodologia fundamentada no fluorômetro mostrou-se adequada para verificar a intoxicação antecipada em B. de cumbens submetidas ao amicarbazone e diuron antes mesmo da verificação visual de intoxicação.

Coeficiente do tanque Classe A obtido por diferentes métodos em ambiente protegido e no campo

There are several methods for determining the Class-A pan coefficient (Kp) to estimate the reference evapotranspiration (ETo), which is of great importance to water management in agriculture. Most of these methods take into account the wind speed, relative humidity and the fetch area. This study was done in region of Botucatu, SP, in greenhouse and field in the months of July-August (dry) and September-October (rainy), used the methods of Doorenbos e Pruitt (1977), Cuenca (1989), Snyder (1992), Pereira et al. (1995), Allen et al. (1998) and correlation between ETo determined by Penman-Monteith (EToPM) and evaporation of the Class-A pan (ECA). The EToPM was used as standard for the correlations between the ETo determined by the Class-A pan (EToTCA) obtained by different methods of Kp. The Kp in greenhouse ranged between 0.51 and 0.85, and in the field from 0.33 to 0.85. The methods of Allen et al. (1998) and Snyder (1992) are the most recommended for dry months in greenhouse and rainy months the correlation between the ECA and EToPM e Cuenca (1989). In the field condition, the methods of Allen et al. (1998) and of correlation between the ECA and EToPM for dry months, and for rainy months of Allen et al. (1998) and Cuenca (1989). The method of Allen et al. (1998) was the most efficient, regardless of the environment and of months analyzed. The fixed value of Kp should only be used when it is not possible to determine from its more sophisticated methods.

Molecular architecture of thin films fabricated via physical vapor deposition and containing a poly(azo)urethane

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Physical Vapor Deposited Thin Films of Lignins Extracted from Sugar Cane Bagasse: Morphology, Electrical Properties, and Sensing Applications

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Molecular architecture and electrical properties in evaporated films of cobalt phthalocyanine

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Structural and Electric-Optical Properties of Zinc Phthalocyanine Evaporated Thin Films: Temperature and Thickness Effects

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluation of the spouted bed dried leaf extract of Bauhinia forficata for the treatment of experimental diabetes in rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Praziquantel-loaded PLGA nanoparticles: preparation and characterization

Nanoparticles containing praziquantel made of Poly (D,L-lactide-co-glycolide) were designed by an emulsion-solvent evaporation method. Two organic solvents were separately utilized as disperse phase: methylene chloride and ethyl acetate. The size of the particles prepared with the former solvent was bigger than the particles prepared with the latter. The entrapment efficiency was bigger when methylene chloride was used, 79.82% in comparison with 29.27% by using ethyl acetate. DSC and infrared studies showed that no strong chemical interaction between drug and polymer occurred. Release kinetics of praziquantel, used as a model drug, was governed not only by actual drug loading but also by particles size. The higher the drug content and the smaller the particle size resulted in faster drug release.

PLGA nanoparticles containing praziquantel: effect of formulation variables on size distribution

Praziquantel has been shown to be highly effective against all known species of Schistosoma infecting humans. Spherical nanoparticulate drug carriers made of poly(D,L-lactide-co-glycolide) acid with controlled size were designed. Praziquantel, a hydrophobic molecule, was entrapped into the nanoparticles with theoretical loading varying from 10 to 30% (w/w). This investigates the effects of some process variables on the size distribution of nanoparticles prepared by emulsion-solvent evaporation method. The results show that sonication time, PLGA and drug amounts, PVA concentration, ratio between aqueous and organic phases, and the method of solvent evaporation have a significant influence on size distribution of the nanoparticles. (C) 2004 Elsevier B.V. All rights reserved.

Nanoencapsulation and Characterization of Zidovudine on Poly(L-lactide) and Poly(L-lactide)-Poly(ethylene glycol)-Blend Nanoparticles

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A new approach to the granulation of beta-cyclodextrin inclusion complexes

Cyclodextrins (CDs) are annular oligosaccharides containing 6-12 glucose unities joined together by alpha-1,4 bonds. They have a conical-truncated shape with a lipophilic cavity in which different molecules can be included resulting in a stable inclusion complex. The cyclodextrins have been widely applied in pharmaceutical technology with the objective of increasing the solubility, stability and bioavailability of drugs in different pharmaceutical dosage forms, such as tablets. In order to obtain beta-CD tablets, liquid dispersions of drug/beta-CD are usually submitted to different drying processes, like spray-drying, freeze-drying or slow evaporation, being this dry material added to a number of excipients. However, such drying processes can generate particulate materials showing problems of flow and compressibility, needing their conversion into granulates by means of wetting with granulation liquid followed by additional drying. In this work, the main objective was to evaluate the preparation of tablets without the need of this additional drying step. For this purpose an aqueous dispersion containing acetaminophen/beta-CD complex and cornstarch was dried using a spouted bed and the obtained granules were compressed in tablets. Acetaminophen was used as model drug due to its low water solubility and the inexpensive and widely available cornstarch was chosen as excipient. Acetaminophen powder was added into a beta-cyclodextrin solution prepared in distilled water at 70 degrees C. Stirring was kept until this dispersion cooled to room temperature. Then cornstarch was added and the resulting dispersion was dried in spouted bed equipment. This material was compressed into tablets using an Erweka Korsh EKO tablet machine. This innovative approach allowed the tablets preparation process to be carried out with fewer steps and represents a technological reliable strategy to produce beta-cyclodextrin inclusion complexes tablets. (C) 2010 Elsevier By. All rights reserved.

Solid dispersions with hydrogenated castor oil increase solubility, dissolution rate and intestinal absorption of praziquantel

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Morphological study of the thorax of the five nymphal instars of Triatoma arthurneivai Lent & Martins (Hemiptera, Reduviidae, Triatominae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Characterization of metallic electrical contacts to SnO2 thin films lightly doped with Eu3+ ions, and photo-induced resistivity

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Growth of Al2O3 thin film by oxidation of resistively evaporated Al on top of SnO2, and electrical properties of the heterojunction SnO2/Al2O3

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)