76 research outputs found
Influence of polyelectrolyte on the electrochemical response of single-walled carbon nanotubes-modified electrodes for biosensing.
Productivity, quality of fruits and architecture of Jalapeño pepper at different planting densities.
Mechanizing the harvest of Jalapeño pepper involves changes in the production system. Spacings between plants in rows (10 to 40 cm; 60 cm fixed between rows) were evaluated in relation to plant architecture, productivity and fruit quality of cultivar BRS Sarakura during three years, in a randomized complete block design with five replicates. Productivity (41.9 to 78.8 t ha-1) and plant height (40.1 to 47.3 cm) responded linearly to density; on the other hand, productivity per plant responded negatively (0.48 to 1.04 kg plant-1)
Preparação e caracterização de membranas assimétricas de poli (fluoreto de vinilideno) suportadas em poliéster - I: efeito do tratamento térmico nas propriedades das membranas
Use of Opuntia ficus-indica (L.) Mill extracts from Brazilian Caatinga as an alternative of natural moisturizer in cosmetic formulations
Associação entre a percepção de atributos ambientais e excesso de peso: um estudo realizado em um município de pequeno porte
Enhanced and tunable photoluminescence of polyphenylenevinylenes confined in nanocomposite films
Energy transfer in nanostructured films containing poly(p-phenylene vinylene) and acceptor species.
The combination of luminescent polymers and suitable energy-accepting materials may lead to a molecularlevel control of luminescence in nanostructured films. In this study, the properties of layer-by-layer (LbL) films of poly(p-phenylene vinylene) (PPV) were investigated with steady-state and time-resolved fluorescence spectroscopies, where fluorescence quenching was controlled by interposing inert polyelectrolyte layers between the PPV donor and acceptor layers made with either Congo Red (CR) or nickel tetrasulfonated phthalocyanine (NiTsPc). The dynamics of the excited state of PPV was affected by the energy-accepting layers, thus confirming the presence of resonant energy transfer mechanisms. Owing to the layered structured of both energy donor and acceptor units, energy transfer varied with the distance between layers, r, according to 1/rn with n ) 2 or 3, rather than with 1/r6 predicted by the Fo¨rster theory for interacting point dipoles
Impedance sensing of DNA hybridization onto nanostructured phthalocyanine-modified electrodes
DNA detection is still undergoing major innovations in pursuit of low-cost and simple approaches for decentralized applications. Label-free sensing of DNA hybridization via impedance measurements is a popular strategy to fulfil the goals of cost-efficiency and simplicity. Several materials are often reported for electrode modification to improve the sensitivity of impedance-based sensors. Herein we evaluate the electronic properties of copper phthalocyanine tetrasulfonate (CuPcTs) in Layer-by-Layer (LbL) films for impedimetric sensing of DNA hybridization using silanized Fluorine-doped Tin Oxide (FTO) electrodes. 1 to 5 bilayers were prepared by alternate immersion of the substrate in CuPcTs and poly(allylamine hydrochloride) (PAH). DNA probe immobilization was carried out electrostatically onto the last PAH layer, followed by hybridization with the target sequence leading to the formation of a partial double stranded (pds) structure onto the films. Impedance decreased after hybridization proportionally with the concentration of the target sequence at picomolar levels. Not only are these findings useful as a potential biosensing strategy, but also leave an open question about the electronic and synergistic properties of DNA interacting with different materials and surfaces. (C) 2016 Elsevier Ltd. All rights reserved.Marie Curie Actions FP7-PEOPLE-IRSESUCMCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Univ Sao Paulo, Inst Fis Sao Carlos, Ave Trabalhador Sao Carlense 400, BR-13566970 Sao Carlos, SP, BrazilUniv Fed Sao Paulo, Inst Ciencia & Tecnol, Ave Cesare Mansueto Giulio Lattes 1201, BR-12247014 Sao Jose Dos Campos, BrazilUniv Oviedo, Fac Quim, Calle Juan Claveria 8, Oviedo 33006, SpainUniv Complutense Madrid, Fac Farm, Plaza Ramon y Cajal S-N, E-28040 Madrid, SpainInstituto de Ciência e Tecnologia, Universidade Federal de São Paulo, Avenida Cesare Mansueto Giulio Lattes 1201, 12247-014 São José dos Campos, BrazilMarie Curie Actions FP7-PEOPLE-IRSES: 612545UCM: BE43/11Web of Scienc
Lavras do Sul: A New Equilibrated Ordinary L5 Chondrite from Rio Grande do Sul, Brazil
The new Brazilian chondrite, Lavras do Sul, was found in 1985 at Lavras do Sul, Rio Grande do Sul State-Brazil (33°30′48″S; 53°54′65″W). It consists of a single mass weighing about 1 kg, covered by a black fusion crust with grayish interior. Four polished thin sections were prepared from a slice weighing 67 g on deposit at the Museu Nacional/UFRJ. It consists mostly of chondrules and chondrule fragments dispersed in a recrystallized matrix. Most chondrules are poorly defined and range in size from 300 to 2,000 μm, although some of them show distinct outlines, particularly when viewed under cross-polarized transmitted and reflected light. The texture of chondrules varies from non-porphyritic (e.g., barred-olivine, radial-pyroxene) to porphyritic ones (e.g., granular olivine as well as olivine-pyroxene). The meteorite contains mainly olivine (Fa24.9), low-Ca pyroxene (Fs22.6) and metal phases, with minor amounts of plagioclase, chromite and magnetite. Mössbauer Spectroscopy studies indicate that the metal phase is kamacite, tetrataenite and antitaenite. Veins of secondary iddingsite crosscut the thin section and some ferromagnesian silicates. The chemical composition indicates that Lavras do Sul is a member of the low iron L chondrite group. The poorly delineated chondritic texture with few well-defined chondrules, the occurrence of rare clinopyroxene and plagioclase (and maskelynite) with apparent diameters ranging from 5 to 123 μm led us to classify Lavras do Sul as an equilibrated petrologic type 5. The shock features of some minerals suggest a shock stage S3, and the presence of a small amount of secondary minerals such as iddingsite and goethite, a degree of weathering W1. The meteorite name was approved by the Nomenclature Committee (Nom Com) of the Meteoritical Society (Meteoritic Bulletin Nº99).Fil: Zucolotto, M. E.. Universidade Federal Do Rio de Janeiro. Museu Nacional; BrasilFil: Antonello, Loiva. Centro Brasileiro de Pesquisas Fisicas; BrasilFil: Varela, Maria Eugenia. Consejo Nacional de Investigaciones CientiÂficas y Tecnicas. Centro Cientifico Tecnologico San Juan. Instituto de Ciencias Astronomicas de la Tierra y del Espacio; ArgentinaFil: Scorzelli, R. B.. Centro Brasileiro de Pesquisas Fisicas; BrasilFil: Ludka, Isabel P.. Universidade Federal Do Rio de Janeiro. Instituto de Geociências; BrasilFil: Munayco, P.. Centro Brasileiro de Pesquisas Fisicas; BrasilFil: Dos Santos, E.. Centro Brasileiro de Pesquisas Fisicas; Brasi
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