985 resultados para Omega


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Highly unsaturated fatty acids derived from fish or algal oils, particularly EPA and DHA, are in high demand as healthy food ingredients in fortified foods. Due to their oxidative instability most food products incorporate stabilized microencapsulated EPA and DHA oils to avoid negative sensory impact associated with oxidation of these fatty acids. Complex coacervation has been particularly successful in stabilizing fish oil and providing an ingredient with a sensory shelf-life consistent with that of the food product. Overcoming the technical challenges associated with the instability of these oils will help drive growth of the omega-3 fortified healthy food ingredient market.

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We describe a simple experiment which allows unequivocal determination of optical phase change upon reflection of light at the mica-silver interface. While the physical origin of such a phase change at the dielectric-metal interface is well understood to lie in absorption of electromagnetic energy by the metal, inconsistency and ambiguity has persisted as to what its sign and magnitude should be in the field of thin film optics. Most commonly, it has been assigned to be negative for mathematical convenience or just arbitrarily. Our finding shows that with the convention exp(-iωt) for time dependence of the electromagnetic wave, the phase change at the interface between mica and the thin silver film is necessarily positive and its magnitude falls between π and 3π/2 for silver thicknesses down to nanometres. This gives a physically reasonable correspondence to an increased equivalent thickness of the dielectric material, and it clarifies the assignment of interference orders in the harmonic series in a spectrum.

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The aim of this study was to develop and evaluate a dietary screening tool for use in a secondary cardiovascular disease (CVD) prevention setting to identify an individual’s overall dietary quality. The Diet Quality Tool (DQT) was validated against a 4-day food diary for 37 individuals with established CVD attending cardiac rehabilitation. Construct validity was demonstrated for % energy from saturated fat (P = 0.002, r = –0.500), dietary fibre (P < 0.001, r = 0.559) and omega-3 fatty acids (P = 0.048, r = 0.327). Criterion validity was established with a significant difference found between mean (95% CI) dietary intakes of fibre (28.2 g, 4.4 to 17.3) and % total energy from saturated fat (10.6%, –4.8 to –0.8) for those with better DQT scores (>60%) versus those with poorer scores (≤60%) when compared with 4-day food diary nutrient values. The usefulness of the DQT was confirmed by both patients (n = 25) and cardiac rehabilitation health professionals (n = 8). The DQT was found to be a valid and useful dietary assessment tool with potential for use in a secondary CVD prevention setting. The tool has the capacity to be used in a wider variety of settings and further refinement of the tool would enable a greater amount of nutrients to be reliably screened.

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Patternable, electrically conductive coatings having a superhydrophobic and superoleophobic surface have been prepared by one-step vapour-phase polymerisation of polypyrrole in the presence of a fluorinated alkyl silane directly on fibrous substrates. The coated fabrics showed a surface resistance of 0.5-0.8 k&Omega; □-1 with water and hexadecane contact angles of 165° and 154°, respectively.

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PET fabric is coated with conducting polypyrrole (PPy) by oxidative polymerization from an aqueous solution of Py using ferric chloride hexahydrate (FeCl3) as oxidant and p-toluene sulphonate (pTSA) as dopant. The optimum concentrations for Py, FeCl3 and pTSA were found to be 0.11, 0.857 and 0.077 mol/l respectively, which yielded a conductive fabrics with resistivity as low as 72 &Omega;/sq. PPy fabric gained resistivity less than one order of magnitude when aged for 18 months at room temperature. The stabilizing effect of the dopant pTSA against thermal degradation was demonstrated; the undoped samples reached resistivity of around 40 k&Omega;, whereas doped samples reached less than 2 k&Omega; at the same temperature and time.

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This study characterizes BaCo0.7Fe0.2Nb0.1O3−δ (BCFN) perovskite oxide and evaluates it as a potential cathode material for proton-conducting SOFCs with a BaZr0.1Ce0.7Y0.2O3-δ (BZCY) electrolyte. A four-probe DC conductivity measurement demonstrated that BCFN has a modest electrical conductivity of 2–15 S cm−1 in air with p-type semiconducting behavior. An electrical conductivity relaxation test showed that BCFN has higher Dchem and Kchem than the well-known Ba0.5Sr0.5Co0.8Fe0.2O3−δ oxide. In addition, it has relatively low thermal expansion coefficients (TECs) with values of 18.2 × 10−6 K−1 and 14.4 × 10−6 K−1 at temperature ranges of 30–900 °C and 30–500 °C, respectively. The phase reaction between BCFN and BZCY was investigated using powder and pellet reactions. EDX and XRD characterizations demonstrated that BCFN had lower reactivity with the BZCY electrolyte than strontium-containing perovskite oxides such as SrCo0.9Nb0.1O3-δ and Ba0.6Sr0.4Co0.9Nb0.1O3−δ. The impedance of BCFN was oxygen partial pressure dependent. Introducing water into the cathode atmosphere reduced the size of both the high-frequency and low-frequency arcs of the impedance spectra due to facilitated proton hopping. The cathode polarization resistance and overpotential at a current density of 100 mA cm−2 were 0.85 &Omega; cm−2 and 110 mV in dry air, which decreased to 0.43 &Omega; cm−2 and 52 mV, respectively, in wet air (∼3% H2O) at 650 °C. A decrease in impedance was also observed with polarization time; this was possibly caused by polarization-induced microstructure optimization. A promising peak power density of ∼585 mW cm−2 was demonstrated by an anode-supported cell with a BCFN cathode at 700 °C.

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Cobalt-free perovskite cathode with excellent oxygen reduction reaction (ORR) properties below 800 °C is a key material toward wide implementation of intermediate-temperature solid oxide fuel cells. This work reports the phase structure, microstructure and performance of such cathode based on the composite phases of triclinic Ba0.9Bi0.1FeO3-δ, cubic BaFeO3 and orthorhombic BaFe2O4 prepared by sol–gel route. The resultant barium ferrites composite cathode exhibits uniform particles, pores and elements distribution. In particular, favorable ORR properties of this cathode is demonstrated by very low interfacial resistance of only 0.036 and 0.072 &Omega; cm2 at 750 and 700 °C and maximum power density of 1295 and 840 mW cm−2 at 750 and 700 °C.

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An expanding body of scientific research indicates that the marine environment is emerging as a unique resource of functional food ingredients with health-promoting properties. Significant attention has been paid to exploration of potential nutraceuticals and pharmaceuticals derived from the ocean. Marine-based  nutraceuticals are gaining attention due to their unique features, which are absent in terrestrial-based resources. A number of new marine nutraceutical products have been introduced in the nutraceuticals and functional foods markets. The main sources and products of primary interest for marine nutraceuticals and ingredients include omega-3 fish/algal oil, phospholipids, micro/macro algal nutrition supplements, fish proteins and peptides, hydrolysates, shellfish chitin, fish collagen, and mineral supplements.

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The research describes a rapid method for the determination of fatty acid (FA) contents in a micro-encapsulated fish-oil (μEFO) supplement by using attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopic technique and partial least square regression (PLSR) analysis. Using the ATR-FTIR technique, the μEFO powder samples can be directly analysed without any pre-treatment required, and our developed PLSR strategic approach based on the acquired spectral data led to production of a good linear calibration with R2 = 0.99. In addition, the subsequent predictions acquired from an independent validation set for the target FA compositions (i.e., total oil, total omega-3 fatty acids, EPA and DHA) were highly accurate when compared to the actual values obtained from standard GC-based technique, with plots between predicted versus actual values resulting in excellent linear fitting (R2 ⩾ 0.96) in all cases. The study therefore demonstrated not only the substantial advantage of the ATR-FTIR technique in terms of rapidness and cost effectiveness, but also its potential application as a rapid, potentially automated, online monitoring technique for the routine analysis of FA composition in industrial processes when used together with the multivariate.

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This paper reviews new drug targets in the treatment of depression and new drug candidates to treat depression. Depression is characterized by aberrations in six intertwined pathways: (1) inflammatory pathways as indicated by increased levels of proinflammatory cytokines, e.g. interleukin-1 (IL-1), IL-6, and tumour necrosis factor α. (2) Activation of cell-mediated immune pathways as indicated by an increased production of interferon γ and neopterin. (3) Increased reactive oxygen and nitrogen species and damage by oxidative and nitrosative stress (O&NS), including lipid peroxidation, damage to DNA, proteins and mitochondria. (4) Lowered levels of key antioxidants, such as coenzyme Q10, zinc, vitamin E, glutathione, and glutathione peroxidase. (5) Damage to mitochondria and mitochondrial DNA and reduced activity of respiratory chain enzymes and adenosine triphosphate production. (6) Neuroprogression, which is the progressive process of neurodegeneration, apoptosis, and reduced neurogenesis and neuronal plasticity, phenomena that are probably caused by inflammation and O&NS. Antidepressants tend to normalize the above six pathways. Targeting these pathways has the potential to yield antidepressant effects, e.g. using cytokine antagonists, minocycline, Cox-2 inhibitors, statins, acetylsalicylic acid, ketamine, &omega;3 poly-unsaturated fatty acids, antioxidants, and neurotrophic factors. These six pathways offer new, pathophysiologically guided drug targets suggesting that novel therapies could be developed that target these six pathways simultaneously. Both nuclear factor (erythroid-derived 2)-like 2 (Nrf2) activators and glycogen synthase kinase-3 (GSK-3) inhibitors target the six above-mentioned pathways. GSK-3 inhibitors have antidepressant effects in animal models of depression. Nrf2 activators and GSK-3 inhibitors have the potential to be advanced to phase-2 clinical trials to examine whether they augment the efficacy of antidepressants or are useful as monotherapy.

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Marine microbes are competent organisms, some of which can accumulate large amounts of lipids. A yeast strain, Rhodotorula mucilaginosa AMCQ8A was isolated from the marine water of the Queenscliff region, Victoria, Australia. The yeast isolate was identified by sequencing 18s rDNA genes. Scanning electron microscopy images revealed scars on the surface of the yeast cells. The Fourier transform infrared spectroscopy microspectroscopy studies demonstrated the presence of unsaturated fatty acids by differential microscopic analysis. The sharp band at 1745 cm-1 was represented by ν(C=O) stretches of ester functional groups from lipids and fats, and therefore indicated the presence of total lipids produced by the cells. Over 65% of the fatty acids from the yeast strain were analyzed as C16 and C18:1 with omega-3 content from about 6% to 7%. Thus, this marine-derived yeast could be a potential source of lipids, including omega-3 fatty acids. 2012, The Society for Biotechnology, Japan. All rights reserved.

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This thesis examines the direct interaction of Docosahexaenoic acid (DHA, an omega-3 fatty acid) against zinc-induced mitochondrial dysfunction and involvement of bioenergetic regulation as a zinc toxicity target, which may be the initiator of oxidative stress, caspase cascade, alteration in epigenetic patterns and therefore gene expression in human neuronal cells.

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Dietary deficiency of &omega;-3 fatty acids (&omega;-3 DEF) produces hypertension in later life. This study examined the effect of &omega;-3 DEF on blood pressure and hypothalamic gene expression in young rats, before the development of hypertension, and in older rats following the onset of hypertension. Animals were fed experimental diets that were deficient in &omega;-3 fatty acids, sufficient in short-chain &omega;-3 fatty acids or sufficient in short- and long-chain &omega;-3 fatty acids, from the prenatal period until 10 or 36 weeks-of-age. There was no difference in blood pressure between groups at 10 weeks-of-age; however, at 36 weeks-of-age &omega;-3 DEF animals were hypertensive in relation to sufficient groups. At 10 weeks, expression of angiotensin-II1A receptors and dopamine D3 receptors were significantly increased in the hypothalamic tissue of &omega;-3 DEF animals. In contrast, at 36 weeks, α2a and β1 adrenergic receptor expression was significantly reduced in the &omega;-3 DEF group. Brain docosahexaenoic acid was significantly lower in &omega;-3 DEF group compared with sufficient groups. This study demonstrates that dietary &omega;-3 DEF causes changes both in the expression of key genes involved in central blood pressure regulation and in blood pressure. The data may indicate that hypertension resulting from &omega;-3 DEF is mediated by the central adrenergic system.

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The neuronal voltage-gated N-type calcium channel (Cav2.2) is a validated target for the treatment of neuropathic pain. A small library of anthranilamide-derived &omega;-Conotoxin GVIA mimetics bearing the diphenylmethylpiperazine moiety were prepared and tested using three experimental measures of calcium channel blockade. These consisted of a 125I-&omega;-conotoxin GVIA displacement assay, a fluorescence-based calcium response assay with SH-SY5Y neuroblastoma cells, and a whole-cell patch clamp electrophysiology assay with HEK293 cells stably expressing human Cav2.2 channels. A subset of compounds were active in all three assays. This is the first time that compounds designed to be mimics of &omega;-conotoxin GVIA and found to be active in the 125I-&omega;-conotoxin GVIA displacement assay have also been shown to block functional ion channels in a dose-dependent manner.