Towards new botanical pesticides: the toxic effect of Eremanthus goyazensis (Asteraceae) leaves essential oil against Brevipalpus phoenicis (Acari: Tenuipalpidae)

This work reports the chemical characterization of Eremanthusgoyzensis essential oil and its toxic effect over Brevipalpus phoenicis. The essential oil displayed a major composition of sesquiterpenes (61.87%) including trans-caryophillene (26.81%) and germacrene-D (13.31%). The fumigation test indicated a promising bioactivity over adult B. phoenicis individuals at 24 h (2.03 µL/L of air) and 48 h (1.08 µL/L of air) of exposition. A brief discussion of essential oils composition and their singular role on the toxic effect over B. phoenicis is provided here. Our results may contribute to a new and profitable use of a species of Brazilian flora on agribusiness.

Effect of soybean oil and Tween 80 on the production of botryosphaeran by Botryosphaeria rhodina MAMB-05

The addition of soybean oil and Tween 80 was evaluated with the objective of increasing the production of botryosphaeran, an exopolysaccharide (EPS) of the (1 -> 3 ;1 -> 6)-beta-D-glucan type produced by the fungus Botowsphaeria rhodina MAMB-05. Factorial design and analysis by response surface methodology was developed to select the main factors that would affect and enhance EPS production. The optimized culture conditions were: 40g l(-1) glucose with 10ml l(-1) soybean oil, and 4.5 ml l(-1) Tween 80, during 72h cultivation at 28 degrees C (180 rpm) and initial pH 5.7. The predicted result for botryosphaeran production was 8.22 +/- 1.36 g l(-1), and compared with the experimental value of 7.74 +/- 0.13 g l(-1) . Partial characterization of the botryosphaeran produced under the optimized conditions showed one type of polysaccharide with P-glycosidic linkages containing glucose as monosaccharide. (c) 2007 Elsevier Ltd. All rights reserved.

Electrochemical characterization of the paste carbon modified electrode with KSr2Ni0.75Nb4.25O15-delta solid in catalytic oxidation of the dipyrone

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

Thermal study and physico-chemical characterization of some functional properties of guava seeds protein isolate (Psidium guajava)

The guava seed protein isolate ( PI) was obtained from the protein precipitation belonging to the class of the gluteline (Ip 4.5). The conditions for the preparation of the PI were determined by both the solubility curve and simultaneous thermogravimetry-differential thermal analysis (TG-DTA): pH 11.5, absence of NaCl and whiteners and T=( 25 +/- 3) degrees C. Under these conditions a yield of 77.0 +/- 0.4%, protein content of 94.2 +/- 0.3, ashes 0.50 +/- 0.05% and thermal stability, T= 200 degrees C, were obtained. The TG-DTA curves and the PI emulsification capacity study showed the presence of hydrophobic microdomains at pH 11.5 and 3.0 suggesting a random coil protein conformation and, to pH 10.0, an open protein conformation. The capacity of emulsification (CE), in the absence of NaCl, was verified for: 1 - pH 3.0 and 8.5, using the IP extracted at pH 10.0 and 11.5, CE >= 343 +/- 5 g of emulsified oil/g of protein; 2 - pH 6.60 just for the PI obtained at pH 11.5, CE >= 140 +/- 8 g of emulsified oil/g of protein.

Thermal characterization of solid lipid nanoparticles containing praziquantel

Solid lipid nanoparticles (SLNs), loaded and unloaded with praziquantel (PRZ-load SLN and PRZ-unload SLN) were prepared by two different procedures: (a) oil-in-water hot microemulsion method, obtaining at 70 degrees C an optically transparent blend composed of surfactant, co-surfactant, and water; and (b) oil-in-water microemulsion method, dissolving the lipid in an immiscible organic solvent, emulsified in water containing surfactants and co-surfactant, and then evaporated under reduced pressure at 50 degrees C. The mean diameter, polydispersity index (PdI), and zeta potential were 187 to 665 nm, 0.300 to 0.655, and -25 to -28 mV respectively, depending on the preparation method. The components, binary mixture, SLNs loaded and unloaded with PRZ, and physical mixture were evaluated by differential scanning calorimetry (DSC) and thermogravimetry (TG). The non-isothermal isoconversional Flynn-Wall-Ozawa method was used to determine the kinetic parameters associated with the thermal decomposition of the samples. The experimental data indicated a linear relationship between the apparent activation energy E and the pre-exponential factor A, also called the kinetic compensation effect (KCE), allowing us to determine the stability with respect to the preparation method. Loading with PRZ increased the thermal stability of the SLNs.

Structural characterization and in vivo evaluation of retinyl palmitate in non-ionic lamellar liquid crystalline system

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

Anelastic characterization and superconducting properties of RuSr2GdCu2O8+delta

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Cure Kinetic of Castor Oil-Based Polyurethane

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Structure and Applications of a Rhamnolipid Surfactant Produced in Soybean Oil Waste

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

Characterization of the Pulp and Kernel Oils from Syagrus oleracea, Syagrus romanzoffiana, and Acrocomia aculeata

Vegetable oils are important sources of essential fatty acids. It is, therefore, important to characterize plant species that can be used as new oil sources. This study aimed to characterize the oils from guariroba (Syagrus oleracea), jeriva (Syagrus romanzoffiana), and macauba (Acrocomia aculeata). The physicochemical characterization was performed using official analytical methods for oils and fats, free fatty acids, peroxide value, refractive index, iodine value, saponification number, and unsaponifiable matter. The oxidative stability was determined using the Rancimat at 110 degrees C. The fatty acid composition was performed by gas chromatography. The results were submitted to Tukey's test for the medium to 5% using the ESTAT program. The pulp oils were more unsaturated than kernel oils, as evidenced by the higher refractive index and iodine value, especially the macauba pulp oil which gave 1.4556 and 80 g I(2)/100 g, respectively, for these indices. The kernel oils were less altered by oxidative process and had high induction period, free fatty acids below 0.5%, and peroxide value around 0.19 meq/kg. The guariroba kernel oil showed the largest induction period, 91.82 h.

Synthesis and characterization of silver nanoparticles impregnated into bacterial cellulose

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

Characterization and application of PZT/PU and graphite doped PZT/PU composite

Composites, made of lead zirconate titanate (PZT) ceramic powder and castor oil-based polyurethane (PU), were prepared in the film form. The films were obtained in the thickness range 100-300 mum using up to 50/50 vol.% of ceramic. Another composite (PZT/C/PU) was obtained by adding a small amount (1.0 vol.%) of graphite (C) to the PZT/PU composite. By increasing the conductivity of PU-containing graphite, polarization of PZT could be carried out with better efficiency. A comparison of piezo- and pyroelectric activities and spatial distribution of polarization between graphite doped and undoped composites reveal the advantages of using semiconductor filler. These composites were used as sensors to detect acoustic emission (AE). The detection was made using two simulated sources of AE, i.e., ball bearing drop and pencil lead break. PZT/C/PU composite was able to detect both flexural and extensional components of wave vibration. (C) 2002 Elsevier B.V. B.V. All rights reserved.

Morphology characterization of layer-by-layer films from PAH/MA-co-DR13: the role of film thickness

We report on the use of dynamic scale theory and fractal analyses in the Study of distinct growth stages of layer-by-layer (LBL) films of poly(allylamine hydrochloride) (PAH) and a side-chain-substituted azobenzene copolymer (Ma-co-DR13). The LBL films were adsorbed oil glass substrates and characterized with atomic force microscopy with the Ma-co-DR13 at the top layer. The ganular morphology exhibited by the films allowed the observation of the growth process inside and outside the grains. The growth outside the grains was found to follow the Kardar-Parisi-Zhang model, with fractal dimensions of ca. 2.6. One could expect that inside the grains the morphology would be close to a Euclidian surface with fractal dimension of ca. 2 for any growth stage. The latter, however, was observed only for thicker films containing more than 10 bilayers. For thinner films the morphology was well described by a self-affine fractal. Such dependence of the growth behavior with the film thickness is associated with a more complete coverage of adsorption sites in thicker films due to diffusion of polymer molecules. (c) 2004 Elsevier B.V. All rights reserved.

Purification and characterization of two beta-glucosidases from the thermophilic fungus Thermoascus aurantiacus

beta-Glucosidase from the fungus Thermoascus aurantiacus grown oil semi-solid fermentation medium (using ground corncob as substrate) was partially purified in 5 steps - ultrafiltration, ethanol precipitation, gel filtration and 2 anion exchange chromatography runs, and characterized. After the first anion exchange chromatography, beta-glucosidase activity was eluted in 3 peaks (Gl-1, Gl-2, Gl-3). Only the Gl-2 and Gl-3 fractions were adsorbed on the gel matrix. Gl-2 and Gl-3 exhibited optimum pH at 4.5 and 4.0, respectively. The temperature optimum of both glucosidases was at 75-80 degreesC. The pH stability of Gl-2 (4.0-9.0) was higher than Gl-3 (5.5-8.5); both enzyme activities showed similar patterns of thermostability. Under conditions of denaturing gel chromatography the molar mass of Gl-2 and Gl-3 was 175 and 157 kDa, respectively. Using 4-nitrophenyl beta-D-glucopyranoside as substrate, K-m, values of 1.17 +/- 0.35 and 1.38 +/- 0.86 mmol/L were determined for Gl-2 and Gl-3, respectively. Both enzymes were inhibited by Ag+ and stimulated by Ca2+.

Benzocaine loaded biodegradable poly-(D,L-lactide-co-glycolide) nanocapsules: factorial design and characterization

Local anesthetics are able to induce pain relief since they bind to the sodium channel of excitable membranes, blocking the influx of sodium ions and the propagation of the nervous impulse. Benzocaine (BZC) is a local anesthetic that presents limited application in topical formulations due to its low water-solubility. This study aimed to develop polymeric nanocapsules as a drug delivery system for the local anesthetic benzocaine (BZC). To do so, BZC loaded poly(D,L-lactide-co-glycolide) (PLGA) nanocapsules were prepared using the nanoprecipitation method and were characterized. The factorial experimental design was used to study the influence of four different independent variables oil response to nanocapsules drug loading. The physical characteristics of PLGA nanocapsules were evaluated by analyzing the particle size, the polydispersion index and the zeta potential, using a particle size analyzer. The results of the optimized formulation showed a size distribution with a polydispersity index of 0.12. an average diameter of 123 nm, zeta potential of -33.6 mV and a drug loading of more than 69%. The release profiles showed a significant difference in the release behavior for the pure drug in solution when compared with that containing benzocaine loaded PLGA nanocapsules. Thus, the prepared nonocapsules described here may be of clinical importance in both the processes of stabilization and delivery of benzocaine for pain treatment. (c) 2009 Elsevier B.V. All rights reserved.