A simple and green analytical method for determination of glyphosate in commercial formulations and water by diffuse reflectance spectroscopy

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A Simple and Green Analytical Method for the Determination of Formaldehyde

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Green lacewings (Neuroptera: Chrysopidae) associated with Melon Crop in Mossoró, Rio Grande do Norte State, Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Occurrence of Amphiorchis indicus Mehrotra, 1973 (Digenea, Spirorchiidae) infecting Green turtle Chelonia mydas Linnaeus, 1758 (Testudines, Cheloniidae) in Brazil

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

Phosphorus utilization by corn as affected by green manure, nitrogen and phosphorus fertilizers

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

Study of adsorption isotherms of green coconut pulp

O Brasil é considerado um dos maiores produtores e consumidores de frutas tropicais. O coco verde (Cocos nucifera L.) se destaca tanto em termos de produção e consumo quanto em quantidade de resíduos gerada por indústrias de água de coco e pelo consumo in natura. Portanto, existe uma necessidade de aproveitamento deste subproduto. Este trabalho teve por objetivo estudar as isotermas de adsorção da polpa de coco verde e determinação do calor isostérico de sorção. As isotermas de adsorção para as temperaturas de 30, 40, 50, 60 e 70 °C foram analisadas e evidenciaram curvas do tipo III, típicas de alimentos ricos em açúcares. Os dados experimentais de umidade de equilíbrio foram correlacionados por modelos da literatura. O modelo de GAB apresentou melhor concordância com os dados experimentais, entre os modelos avaliados. O calor isostérico de sorção é considerado um indicativo de forças atrativas intermoleculares entre os sítios de sorção de vapor de água, consequentemente, um importante fator para predizer a vida de prateleira de produtos desidratados.

Lipoperoxidation and cyclooxygenase enzyme inhibitory piperidine alkaloids from Cassia spectabilis green fruits

Phytochernical work in the search for bioactive metabolites from the methanolic extract of Senna spectabilis green fruits led to the isolation of a new piperidine alkaloid, (+)-3-O-feruloylcassine (1), in addition to the known (-)-spectaline (2) and (-)-3-O-acetylspectaline (3). The isolates were submitted to in vitro evaluation of lipoperoxidation (LPO) and cyclooxygenase enzymes (COX-1 and -2) inhibitory properties and showed moderate antioxidant activities (40-70%) at 100 ppm when compared to commercial standards BHT and vitamin E and moderate inhibition of COX-1 (ca. 40%) and marginal inhibition of COX-2 enzymes (< 10%) at 100 ppm when compared to nonsteroidal anti-inflammatory drugs (NSAIDs) aspirin, rofecoxib, and celecoxib, respectively.

Further bioactive piperidine alkaloids from the flowers and green fruits of Cassia spectabilis

The flowers of Cassia spectabilis yielded three new piperidine alkaloids, (-)-3-O-acetylspectaline (1), (-)-7-hydroxyspectaline (2), and iso-6-spectaline (3), together with the known (-)-spectaline (4). The green fruits of this plant were also investigated, resulting in the isolation of 1 and 4. Their structures were elucidated using a combination of multidimensional NMR and MS techniques, and relative stereochemistries were established by NOESY correlations and analysis of coupling constants. The DNA-damaging activity of these compounds was evaluated using a mutant yeast, Saccharomyces cerevisiae, assay.

Red-green-blue upconversion emission and energy-transfer between Tm3+ and Er3+ ions in tellurite glasses excited at 1.064 mu m

Red, green, and blue emission through frequency upconversion and energy-transfer processes in tellurite glasses doped with Tm3+ and Er3+ excited at 1.064 mum is investigated. The Tm3+/Er3+-codoped samples produced intense upconversion emission signals at around 480, 530, 550 and 660 nm. The 480 nm blue emission was originated from the (1)G(4)-->H-3(6) transition of the Tm3+ ions excited by a multiphoton stepwise phonon-assisted excited-state absorption process. The 5 30, 5 50 nm green and 660 mn red upconversion luminescences were identified as originating from the H-2(11/2), S-4(3/2) --> I-4(15/2) and F-4(9/2) --> I-4(15/2) transitions of the Er3+ ions, respectively, populated via efficient cross-relaxation processes and excited-state absorption. White light generation employing a single infrared excitation source is also examined. (C) 2003 Elsevier B.V. (USA). All rights reserved.

Green functions of the Dirac equation with magnetic-solenoid field

Various Green functions of the Dirac equation with a magnetic-solenoid field (the superposition of the Aharonov-Bohm field and a collinear uniform magnetic field) are constructed and studied. The problem is considered in 2+1 and 3+1 dimensions for the natural extension of the Dirac operator (the extension obtained from the solenoid regularization). Representations of the Green functions as proper time integrals are derived. The nonrelativistic limit is considered. For the sake of completeness the Green functions of the Klein-Gordon particles are constructed as well. (C) 2004 American Institute of Physics.

Red, green, and blue upconversion luminescence in ytterbium-sensitized praseodymium-doped lead-cadmium-germanate glass

Blue, green, red, and near-infrared upconversion luminescence in the wavelength region of 480-740 nm in Pr3+/Yb3+-codoped lead-cadmium-germanate glass under 980 nm diode laser excitation, is presented. Upconversion emission peaks around 485, 530, 610, 645, and 725 nm which were ascribed to the P-3(0)-H-3(J) (J = 4, 5, and 6), and P-3(0)-F-3(J) (J = 2, 3, and 4), transitions, respectively, were observed. The population of the praseodymium upper P-3(0) emitting level was accomplished through a combination of ground-state absorption of Yb3+ ions at the F-2(7/2), energy-transfer Yb3+(2F(5/2))-Pr3+(H-3(4)), and excited-state absorption of Pr3+ ions provoking the (1)G(4)-P-3(0) transition. The dependence of the upconversion luminescence upon the Yb3+-concentration and diode laser power, is also examined, in order to subsidize the proposed upconversion excitation mechanism. (C) 2004 Elsevier B,V. All rights reserved.

Mechanisms behind blue, green, and red photoluminescence emissions in CaWO4 and CaMoO4 powders

A combined experimental and theoretical study was conducted to analyze the photoluminescence (PL) properties of ordered and disordered CaWO4 (CW) and CaMoO4 (CM) powders. Two mechanisms were found to be responsible for photoluminescence emission in CW and CM powders. The first one, in the disordered powders, was caused by oxygen complex vacancies [MO3 center dot V-O(x)], [MO3 center dot V-O(center dot)] and [MO3 center dot V-O(center dot center dot)], where M=W or Mo, which leads to additional levels in the band gap. The second mechanism, in ordered powders, was caused by an intrinsic slight distortion of the [WO4] or [MoO4] tetrahedral in the short range. (c) 2007 American Institute of Physics.

THE GREEN-FUNCTION IN THE BLOCH-NORDSIECK MODEL FOR QED(3)

The electron Green's function is obtained in the Bloch-Nordsieck approximation of three-dimensional QED. Dimensional regularization is used in the intermediate stages of calculation.

Indocyanine green nanoparticles useful for photomedicine

Objective: the aim of this study was to evaluate the potential application of biodegradable nanoparticles (NPs) containing indocyanine green (ICG) in photodynamic therapy (PDT). Methods: Important parameters, such as particle size and external morphology, were established by dynamic light scattering (DLS) and scanning electron microscopy (SEM). Also, drug encapsulation efficiency and in vitro release behavior were evaluated by spectroscopic methods. Results: the particles are spherical in shape, they exhibit an 817-nm diameter, and they have a low tendency to aggregate. The loading efficiency was 65%. ICG photophysical parameters showed a bathocromic shift in ICG-loaded nanoparticles (ICG-NP). Analysis of the cell P388-D1 in the presence of the ICG-NP by SEM showed that the majority of the nanoparticles were uptaken by phagocytic cells after 2 h of incubation. After laser irradiation photodamage was observed in P388-D1 cells where ICG-NPs had been uptaken by phagocytic cells. Conclusion: Polymeric NPs work as an efficient drug delivery system for PDT drugs, and this approach can be used in the administration of amphiphilic photosensitizers in the treatment of neoplasic cells.