Caracterización térmica y química de fracciones de aceite de semilla de Syagrus romanzoffiana

The Jerivá (Syagrus romanzoffiana) kernel oil (JKO) has a pleasant coconut-like smell, with about 33% lauric acid and 28% oleic acid. The oil also contains bioactive compounds, such as phenolics, carotenoids, and tocopherols. JKO has a solid consistency at low temperatures, but has a low melting point and low solid content at room temperature. Thus, this work aimed to evaluate the thermal properties related to crystallization and fusion, as well as the chemical and oxidative characteristics of JKO fractions, olein and stearin, obtained from dry and solvent fractionation. In general, stearins had higher crystallization and melting temperatures, and higher solid fat content, unlike oleins, which may be associated with the concentration of high melting triglycerides in the stearins. No statistically significant difference was found for fatty acid profile or oxidative stability of the fractions. The type of fractionation influenced the chemical and thermal properties of JKO fractions. The solvent process promoted the most relevant differentiation of fractions. An olein was obtained with 7% less solid fat at 25 °C which remained visually liquid at 2 °C below the oil, as well as a stearin with 17% more solid fat at 25 °C which remained visually solid at 3 °C above the oil.El aceite de semilla de Jerivá (Syagrus romanzoffiana) (ASJ) tiene un agradable olor a coco, con aproximadamente un 33% de ácido láurico y un 28% de ácido oleico. Este aceite también contiene compuestos bioactivos, como fenólicos, carotenoides y tocoferoles. El ASJ tiene una consistencia sólida a baja temperatura, pero tiene un punto de fusión bajo y un contenido de sólidos bajo a temperatura ambiente. Este trabajo tuvo como objetivo evaluar las propiedades térmicas relacionadas con la cristalización y fusión, así como las características químicas y oxidativas de las fracciones de ASJ, oleína y estearina, obtenidas mediante fraccionamiento en seco y con solvente. En general, las estearinas tuvieron temperaturas de cristalización y fusión más altas y un mayor contenido de grasa sólida, a diferencia de las oleínas, esto puede estar asociado con la concentración de triglicéridos de alto punto de fusión en las estearinas. No se encontraron diferencias estadísticamente significativas para el perfil de ácidos grasos ni en la estabilidad oxidativa de las fracciones. El tipo de fraccionamiento influyó en las propiedades químicas y térmicas de las fracciones de ASJK. El proceso mediante solvente favoreció la diferenciación de fracciones más relevantes. Se obtuvo una oleína con 7% menos de grasa sólida a 25 °C que permaneció visualmente líquida a 2 °C por debajo del aceite, así como una estearina con 17% más de grasa sólida a 25 °C y que permaneció visualmente sólida a 3 °C por encima del aceite

TiO2/PDMS nanocomposites for use on self-cleaning surfaces

AbstractIn this study, polydimethylsiloxane (PDMS)/TiO2 nanocomposite was processed by the spray method. TiO2 nanoparticles were synthesized by microwave-assisted hydrothermal method. Varying the proportion of nanoparticles in 0%, 0.5% and 1% by weight, commercial TiO2 (P25) was used for comparison purposes. The photocatalytic activity of nanocomposites impregnated with methylene blue was assessed by means of UV–visible spectroscopy. Changes in contact angle were analyzed before and after UV degradation tests. The effect of ultraviolet radiation on the chemical structure of the PDMS matrix was evaluated by Fourier transform infrared spectroscopy (FTIR). The results indicated that the addition of TiO2 nanoparticles in PDMS provides good photocatalytic properties in the decomposition of methylene blue, which is an important characteristic for the development of coatings for self-cleaning. For comparison purposes, commercial P25 was also used to investigate the photocatalytic activity

Performance of soybean seedlings upon nutrient application by seed coating

The aim of this study was to evaluate the effect of different seed coatings consisting of various combinations of three nutrients (calcium, magnesium and silicon) on two soybean cultivars (BRS 243 RR and CD 233 RR). Dolomitic limestone and aluminum silicate were chosen as the nutrient sources. Leaf area, plant height, shoots dry matter, crop growth rate, relative growth rate and net assimilation rate were the studied variables, evincing that the seed coating that comprised calcium, magnesium and silicon led to better performance in terms of growth rates 30 days after emergence. Significant differences in the response to the seed coatings were also observed between the two studied soybean genotypes

Cryopreservation of caprine ovarian tissue using glycerol and ethylene glycol

Cryopreservation of ovarian tissue may be a potential alternative for the conservation of genetically superior animals, including high milk- and meat-producing goat breeds. However, until now, no information was available concerning the cryopreservation of preantral follicles (PF) enclosed in caprine ovarian tissue. The objective of the present study was to evaluate the structural and ultrastructural characteristics of caprine PF after exposure to and cryopreservation of ovarian tissue in 1.5 and 3 M glycerol (GLY) and ethylene glycol (EG). At the slaughterhouse, each ovarian pair from five adult mixed breed goats was divided into nine fragments and randomly distributed into treatment groups. One fragment was immediately fixed for histological examination and ultrastructural analysis, after slaughter (control). Four of the ovarian fragments were equilibrated at 20 °C for 20 min in 1.8 ml of MEM containing 1.5 or 3 M GLY or EG for a toxicity test and the final four fragments were slowly frozen using these cryoprotectants at the concentrations above. After toxicity testing and freezing/thawing, the ovarian fragments were fixed for histological examination. Histological analysis showed that after toxicity testing and cryopreservation of the ovarian tissue in GLY or EG at both concentrations, the percentage of normal PF was significantly lower than controls. Ultrastructural analysis of PF frozen in 1.5 and 3 M GLY, as well as 3 M EG demonstrated that these follicles remained morphologically normal. In conclusion, we demonstrated cryopreservation of caprine PF in ovarian tissue

Naturally light right-handed neutrinos in a 3-3-1 Model

In this work we show that light right-handed neutrinos, with mass in the sub-eV scale, is a natural outcome in a 3-3-1 model. By considering effective dimension five operators, the model predicts three light right-handed neutrinos, weakly mixed with the left-handed ones. We show also that the model is able to explain the LSND experiment and still be in agreement with solar and atmospheric data for neutrino oscillation.Comment: About 5 pages, no-figure

Discrete symmetries, invisible axion and lepton number symmetry in an economic 3-3-1 model

We show that Peccei-Quinn and lepton number symmetries can be a natural outcome in a 3-3-1 model with right-handed neutrinos after imposing a Z_11 x Z_2 symmetry. This symmetry is suitably accommodated in this model when we augmented its spectrum by including merely one singlet scalar field. We work out the breaking of the Peccei-Quinn symmetry, yielding the axion, and study the phenomenological consequences. The main result of this work is that the solution to the strong CP problem can be implemented in a natural way, implying an invisible axion phenomenologically unconstrained, free of domain wall formation and constituting a good candidate for the cold dark matter.Comment: 17 pages, Revtex

Effect of recombinant human erythropoietin in a rat model of moderate chronic renal failure – focus on inflammation, oxidative Stress and function/renoprotection

Background/Aims: Chronic renal failure (CRF) patients develop anaemia, thus promoting cardiovascular complications, which seems to be favoured by the low kidney erythropoietin (EPO) production. The renal insufficiency degree might determine the moment to start recombinant human EPO (rhEPO) therapy. It has been attributed important non-hematopoietic effects to rhEPO, which might underlie cardio and renoprotection. This work aimed to evaluate the effect of rhEPO in a rat model of moderate CRF, focusing on inflammation, oxidative stress and function/renoprotection. Methods: Four groups (n=7) of male Wistar rats were evaluated during a 15 week follow-up period: control (without treatment); rhEPO (50 IU/Kg/wk Recormon®); CRF and CRF+rhEPO. Blood samples were collected at the beginning and 3, 9 and 12 weeks after 3/4 nephrectomy, in order to evaluate: renal function, haematological parameters, iron metabolism and serum proliferative (TGF-B1), inflammatory (TNF-a, CRP, IL-2 and IL-1B) and redox status (MDA, TAS and 3-NT) markers. Kidney gene expression of Il2, Vegf, Nos2 and Nos3 were assessed by real-time PCR. Blood pressure, heart rate and tissues trophy indexes were also estimated. Results: Our data are consistent with a sustained moderate degree of CRF with development of moderate and corrected anaemia and hypertension. The remnant kidney showed a proliferative profile, with increased mass (hypertrophism), upregulated tissue Vegf gene expression, accompanied by increased levels of serum TGF-B1. Serum 3-NT was augmented, suggesting oxidative stress, which was accompanied by a trend to higher kidney Nos gene expression of both isoforms. rhEPO treatment was able to partially attenuate renal function markers, totally correct anaemia, also demonstrating a proliferative and antioxidant action, suggesting renoprotection. Conclusion: This study suggests that rhEPO therapy might be recommended in moderate CRF stages in order to efficiently correct not only the anaemia but also the underlying deleterious mechanisms, due to a proliferative and antioxidant action on the remnant kidney.info:eu-repo/semantics/publishedVersio

Properties and DEFC tests of Nafion Functionalized titanate nanotubes composite membranes prepared by melt extrusion

Nafion based composites are promising materials to improve the performance of direct ethanol fuel cells. In this work, composite membranes of Nafion and titanate nanotubes functionalized with sulfonic acid groups were prepared by melt extrusion and tested in a direct ethanol fuel cell. Far and mid infrared spectroscopies evidenced the formation of ionic bridges between the sulfonic acid groups of both functionalized nanoparticles and the ionomer. Small angle X ray scattering measurements revealed that the melt extrusion method leads to an uniform distribution of the inorganic phase in the ionomer matrix. Such structural analysis indicated that the improved the proton conduction properties of the composites, even with the addition of a high concentration of functionalized nanoparticles, are an outcome of the synergistic ionic network due to the hydrid organic inorganic proton conducting phases. However, an improvement of the fuel cell performance is observed for 2.5 wt of functionalized titanate nanotubes, which is a result of the lower ethanol crossover and the plasticizing effect of the aliphatic segments of the organic moieties grafted at the surface of the titanate nanoparticle

Acute Hemorrhagic Conjunctivitis and Coxsackievirus A24v, Rio de Janeiro, Brazil, 2004

An outbreak of acute hemorrhagic conjunctivitis (AHC) occurred in Rio de Janeiro in 2004. Coxsackievirus A24v (CA24v) was identified as the etiologic agent, and partial sequences from the VP1 gene show that the isolates are closely related to CA24v viruses that previously caused AHC epidemics in South Korea and French Guiana