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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
471

Development and effect of an N-3 fatty acid-rich spread on the nutritional and cognitive status of school children

Dalton, Annalien 03 1900 (has links)
Thesis (PhD (Food Science))--University of Stellenbosch, 2006. / Long-chain polyunsaturated fatty acids (LCPUFA), especially the n-3 LCPUFA metabolic products eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) play an important role as regulators in many biological processes. To date hake (Merluccius capensis) heads, a rich source of EPA and DHA, have been discarded at sea. The South African Fisheries Policy Development Committee concerned with the environmental impact of this practice has rendered it undesirable. The high prevalence of under-nutrition amongst children in South Africa can be addressed by the supplementation of their diet with this unexploited fish source. The aim of the current study was to develop a microbiologically safe and sensory acceptable sandwich spread using fish flour prepared from fish heads, as a prime ingredient. The intervention trial aimed to compare the effects of an increased dietary intake of n-3 LCPUFA, specifically DHA, on the blood fatty acid levels and absenteeism (as indicator of immune function), as well as the cognitive status, of the subjects. The microbiological content of the sandwich spread was determined after storage for 20 d at 5°C and 15 d at 25°C. Sensory evaluation was performed by consumers (n = 95; M:F = 44:51; 6 – 9 yr) to determine acceptance of the five different flavours individually incorporated into the sandwich spread to mask the fishy note and to provide different flavour options. For the intervention trial subjects (n = 351) were stratified within class group (A - E) and gender and randomly assigned to two treatment categories, an experimental group (EG; n = 174) receiving 25 g sandwich spread.d-1 (191.66 mg DHA. d-1) and a control group (CG; n = 177) receiving an analogous placebo. On school days (104 d), each subject received two sandwiches consisting of two slices of bread (ca. 60 g), spread with 25 g of either the placebo or the experimental spread. Blood samples were drawn at baseline and post intervention. Plasma fatty acid and red blood cell (RBC) membrane status, C-reactive protein levels, as well as vitamin and micronutrient status, were determined. Trained test administrators conducted a battery of cognitive tests. According to South African Government health standards, the sandwich spread remained microbiologically safe after storage. Male and female consumer respondents revealed a significant difference between gender preferences of the five different spread flavours (p <0.05). Significant treatment effects (p <0.05) were observed in n-3 LCPUFA status of the EG, as well as for their absenteeism from school. The two subtests of the Hopkins Verbal Learning test, Recognition and Discrimination Index, showed significant differences between the EG and CG (p <0.05) post intervention in the Grade 2 subjects. The Spelling tests also showed a significant difference between the two groups (p <0.05). In the current study a microbiologically safe and sensory acceptable sandwich spread was developed and tested during an intervention trial, and could possibly in future, provide a healthier option in the School Nutritional Programme. This study proved that supplementation of children (6 - 9 yr) with n-3 LCPUFA, with specific reference to EPA and DHA from a marine source, could have a beneficial effect on their fatty acid status and absenteeism from school. Based on the outcomes of the Hopkins Verbal Learning test and Spelling test, the current study proved that an n-3 fatty acid-rich spread improved the learning ability and memory of children.
472

Hyperon production in p-BE interactions at 158 GeV/c per nucleon at the WA97 CERN experiment

Norman, Paul January 1999 (has links)
No description available.
473

Atténuation de la dépression post-infarctus par une diète riche en oméga-3 ou par la prise de probiotiques

Gilbert, Kim 06 1900 (has links)
L'Infarctus du myocarde (IM) provoque, chez le rat, une augmentation de l'apoptose dans le système limbique en plus d'induire des symptômes qui s'apparentent à la dépression chez l'humain. Nous avons démontré qu'une diète élevée en oméga-3 ou la prise de probiotiques pouvaient être efficaces pour réduire ces effets si ces interventions débutaient avant l'induction de l'ischémie myocardique. Cette étude a pour objectif de déterminer l'efficacité de ces interventions si elles débutent après l'ischémie myocardique. L’IM a été induit chez le rat mâle Sprague-Dawley par l’occlusion de l’artère coronaire descendante antérieure gauche pendant 40 minutes. À la suite de l’ischémie, les rats ont reçu des probiotiques (1 billion de bactéries vivantes de L. helveticus R0052 et de B. longum R0175) ou un véhicule dans leur eau de boisson en présence d'une diète élevée ou faible en oméga-3. À 3 jours post-IM, l’activité enzymatique de la caspase-3 et le nombre de cellules dUTP nick-end labelling (TUNEL) positives sont diminués dans les régions CA1 et le corps godronné de l’hippocampe ainsi que dans l’amygdale en présence de la diète élevée en oméga-3. La prise de probiotiques atténue également l’activité de la caspase-3 et le nombre de cellules TUNEL positives dans le corps godronné et l’amygdale médiane. À 2 semaines post-IM, le comportement dépressif évalué par 3 tests comportementaux (test d’interaction sociale, test de nage forcée et test d’évitement passif) a été observé chez le groupe recevant la diète faible en oméga-3 sans probiotiques et le comportement dépressif a été atténué avec la diète élevée en oméga-3 et/ou la prise de probiotiques. Les probiotiques ont augmenté les niveaux plasmatiques d’interleukine-4 (IL- 4) tandis que la diète élevée en oméga-3 a montré une diminution de la protéine chimiotactique monocytaire 1 (MCP-1). Ces résultats indiquent qu’une diète élevée en oméga-3 ou la prise de probiotiques, débutant à la suite de l’IM, s’avèrent bénéfiques pour atténuer la dépression et l’apoptose dans le système limbique. / Proinflammatory cytokines play a central role in depressive-like behavior and apoptosis in the limbic system after myocardial infarction (MI). Polyunsaturated fatty acids (PUFA) omega-3 diet or the combination of Lactobacillus helveticus R0052 and Bifidobacterium longum R0175 probiotics, when given before ischemic period, reduce circulating proinflammatory cytokines as well as apoptosis in the limbic system. This study was designed to determine if the same nutritional interventions maintain their beneficial effects when started after the onset of the reperfusion period and attenuate depressive-like behavior. MI was induced by the occlusion of the left anterior descending coronary artery for 40 minutes in rats. After the onset of reperfusion, animals were fed with a high or low PUFA omega-3 diet, combined or not with 1 billion live bacteria of L. helveticus R0052 and B. longum R0175. At 3 days post-MI, caspase-3 enzymatic activities and terminal dUTP nickend labelling (TUNEL)-positive cells were decreased in the CA1, dentate gyrus and amygdala with the high PUFA omega-3 diet as compared to the other diet. Probiotics attenuated caspase-3 activity and TUNEL-positive cells in the dentate gyrus and the medial amygdala. At 2 weeks post-MI, depressive-like behaviour, evaluated by 3 behavioural tests (social interaction, passive avoidance and forced swim test), was observed in the low PUFA omega-3 diet without probiotics and this behavior was attenuated with the high PUFA omega-3 diet or/and probiotics. Probiotics increased interleukin-4 plasmatic concentrations while high PUFA omega-3 diet decreased monocyte chemotactic protein 1 (MCP-1). These results indicate that a high PUFA omega-3 diet or the administration of probiotics, starting iii after the onset of reperfusion, are beneficial to attenuate post-MI depression and apoptosis in the limbic system.
474

Solvency considerations in the gamma-omega surplus model

Combot, Gwendal 08 1900 (has links)
Ce mémoire de maîtrise traite de la théorie de la ruine, et plus spécialement des modèles actuariels avec surplus dans lesquels sont versés des dividendes. Nous étudions en détail un modèle appelé modèle gamma-omega, qui permet de jouer sur les moments de paiement de dividendes ainsi que sur une ruine non-standard de la compagnie. Plusieurs extensions de la littérature sont faites, motivées par des considérations liées à la solvabilité. La première consiste à adapter des résultats d’un article de 2011 à un nouveau modèle modifié grâce à l’ajout d’une contrainte de solvabilité. La seconde, plus conséquente, consiste à démontrer l’optimalité d’une stratégie de barrière pour le paiement des dividendes dans le modèle gamma-omega. La troisième concerne l’adaptation d’un théorème de 2003 sur l’optimalité des barrières en cas de contrainte de solvabilité, qui n’était pas démontré dans le cas des dividendes périodiques. Nous donnons aussi les résultats analogues à l’article de 2011 en cas de barrière sous la contrainte de solvabilité. Enfin, la dernière concerne deux différentes approches à adopter en cas de passage sous le seuil de ruine. Une liquidation forcée du surplus est mise en place dans un premier cas, en parallèle d’une liquidation à la première opportunité en cas de mauvaises prévisions de dividendes. Un processus d’injection de capital est expérimenté dans le deuxième cas. Nous étudions l’impact de ces solutions sur le montant des dividendes espérés. Des illustrations numériques sont proposées pour chaque section, lorsque cela s’avère pertinent. / This master thesis is concerned with risk theory, and more specifically with actuarial surplus models with dividends. We focus on an important model, called the gamma-omega model, which is built to enable the study of both periodic dividend distributions and a non-standard type of ruin. We make several new extensions to this model, which are motivated by solvency considerations. The first one consists in adapting results from a 2011 paper to a new model built on the assumption of a solvency constraint. The second one, more elaborate, consists in proving the optimality of a barrier strategy to pay dividends in the gamma-omega model. The third one deals with the adaptation of a 2003 theorem on the optimality of barrier strategies in the case of solvency constraints, which was not proved right in the periodic dividend framework. We also give analogous results to the 2011 paper in case of an optimal barrier under the solvency constraint. Finally, the last one is concerned with two non-traditional ways of dealing with a ruin event. We first implement a forced liquidation of the surplus in parallel with a possibility of liquidation at first opportunity in case of bad prospects for the dividends. Secondly, we deal with injections of capital into the company reserve, and monitor their implications on the amount of expected dividends. Numerical illustrations are provided in each section, when relevant.
475

The HST large programme on omega Centauri - I. Multiple stellar populations at the bottom of the main sequence probed in NIR-Optical

Milone, A. P., Marino, A. F., Bedin, L. R., Anderson, J., Apai, D., Bellini, A., Bergeron, P., Burgasser, A. J., Dotter, A., Rees, J. M. 07 1900 (has links)
As part of a large investigation with Hubble Space Telescope to study the faintest stars within the globular cluster omega Centauri, in this work we present early results on the multiplicity of its main sequence (MS) stars, based on deep optical and near-infrared observations. By using appropriate colour-magnitude diagrams, we have identified, for the first time, the two main stellar Populations I and II along the entire MS, from the turn-off towards the hydrogen-burning limit. We have compared the observations with suitable synthetic spectra of MS stars and conclude that the two main sequences (MSs) are consistent with stellar populations with different metallicity, helium and light-element abundance. Specifically, MS-I corresponds to a metal-poor stellar population ([Fe/H] similar to -1.7) with Y similar to 0.25 and [O/Fe] similar to 0.30. The MS-II hosts helium-rich (Y similar to 0.37-0.40) stars with metallicity ranging from [Fe/H] similar to -1.7 to -1.4. Below the MS knee (m(F160W) similar to 19.5), our photometry reveals that each of the two main MSs hosts stellar subpopulations with different oxygen abundances, with very O-poor stars ([O/Fe] similar to -0.5) populating the MS-II. Such a complexity has never been observed in previous studies of M-dwarfs in globular clusters. A few months before the launch of the James Webb Space Telescope, these results demonstrate the power of optical and near-infrared photometry in the study of multiple stellar populations in globular clusters.
476

Avaliação econômica do uso de ômega-3 na redução dos fatores de risco cardiovascular: análise de custo-efetividade / Economic evaluation of omega-3 use in cardiovascular risk reduction factors: cost-effectiveness analysis

Giaimo, Cinthia Roman Monteiro di 15 May 2019 (has links)
INTRODUÇÃO: As doenças cardiovasculares (DCV) aparecem em primeiro lugar entre as principais causas de mortalidade no mundo, representando 46,2% do total de mortes, número muito próximo aos encontrados no Brasil, impactando os gastos com saúde. A prevenção baseia-se em estilo de vida saudável, contudo, uma vez instaladas, é consenso o tratamento medicamentoso com estatinas. Alguns tratamentos alternativos vêm sendo estudados como o ômega-3 (w-3) na prevenção das DCV. Apesar das evidências clínicas favoráveis, não existem muitos estudos acerca da viabilidade econômica de tais tratamentos. OBJETIVO: Avaliar o custo-efetividade das intervenções com w-3 isolado ou associado às estatinas na redução dos fatores de risco cardiovascular sob a perspectiva do Sistema Único de Saúde (SUS). MATERIAL E MÉTODOS: Para avaliar a efetividade do w-3 isolado e combinado com estatina foram utilizados os dados secundários do ensaio clínico CARDIONUTRI no momento basal e após 8 semanas. A amostra foi composta por 186 indivíduos com idade entre 30 e 74 anos divididos entre aqueles que não tomavam medicação e os que tomavam estatinas. Aleatoriamente, uma parcela deles recebeu cápsulas de 1 g de w-3 (37% de ácido eicosapentaenoico e 23% de docosaexaenoico) ou cápsulas de placebo. A recomendação era de que todos deveriam tomar 3 cápsulas ao dia, totalizando 3g/dia (de w-3 ou placebo) durante 8 semanas. Ao final, obteve-se quatro grupos: a) w-3; b) placebo; c) w-3 + estatina; e d) estatina. Para a avaliação do impacto foi usado o método Diferenças em Diferenças com a adição de variáveis de controle: densidade calórica do consumo alimentar, Índice de Massa Corporal (IMC), prática de atividade física, idade, sexo, raça, hábito tabagista, escolaridade e grau de adesão. Os custos dos tratamentos foram estimados com base no custo médio ponderado pelas probabilidades das eventuais intercorrências relacionadas a efeitos adversos e de sucesso e fracasso por meio do método da árvore de decisão. Foi considerado para fins do cômputo dos custos o período de 2 meses de tratamento. RESULTADOS: Nos quatro grupos, a maioria eram mulheres, obesas e com escore de risco muito alto para DCV. Os grupos w-3 e placebo possuíam maior escolaridade e renda comparadas a aqueles que tomavam estatinas. Todas as variáveis de controle foram estatisticamente significantes em pelo menos um dos modelos, exceto raça. A suplementação com w-3 associada às estatinas mostrou efetividade sobre HDLPEQUENA, com diminuição de 2,211 mg/dL e custo-efetividade de R$ 109,31 por redução em mg/dl da lipoproteína em 2 meses de tratamento. CONCLUSÃO: O tratamento com 1,8g de óleo de peixe isolado ou associado às estatinas em intervenção primária não evidenciou efeitos significativos nas mudanças dos parâmetros lipídicos, exceto no caso da HDLPEQUENA com o tratamento associado, mostrando não ser custo-efetivo na redução dos fatores de risco cardiovascular em geral. Em virtude da existência de controvérsias acerca de seus potenciais efeitos, sugere-se que os ensaios clínicos utilizem métodos estatísticos mais robustos para avaliar o impacto líquido da suplementação. / INTRODUCTION: Cardiovascular diseases (CVD) are among the leading causes of death worldwide, accounting for 46.2% of all cases, very close to those found in Brazil, impacting health expenses. Current prevention is based on a healthy lifestyle, and once a CVD diagnosis is made, the current consensus is drug treatments with statins. Some alternative treatments such as omega-3 (w-3) have been studied in the prevention of these diseases. However, despite favorable clinical evidence, there are not many studies of economic viability of this treatment. OBJECTIVE: To evaluate the cost-effectiveness of interventions with w-3 alone or associated with statins in reducing cardiovascular risk factors from the perspective of the Unified Health System (SUS). METHODS: To assess the effectiveness of w-3 alone and its combination with statin, the secondary data of the classic lipid profile and lipoprotein size of the CARDIONUTRI clinical trial were used at baseline and after 8 weeks. The sample consisted of 186 subjects aged 30 to 74 years randomly received capsules containing 3g of w-3 per day (37% of eicosapentaenoic acid and 23% of docosahexaenoic acid) or 3g of mineral oil (placebo). Capsules were randomly assigned to individuals who were not taking medication or were already taking statins, separated into four groups: a) w-3; b) placebo; c) w-3 associated with statins; d) statins. Data analysis was conducted using the Difference in Differences statistical method with the addition of control variables: caloric density of food consumption, Body Mass Index (BMI), physical activity practice, age, sex, race, smoking, educational level and adherence to the treatment. The treatment costs were estimated based on the weighted average cost by the probabilities of the eventual intercurrences related to adverse effects and of success and failure by means of the decision tree method elapsed in 2 months of treatment. RESULTS: In all four groups, the majority were women, obese and with a very high-risk score for CVD. W-3 and placebo groups had higher educational level and income compared to those who were already taking statins. All control variables were statistically significant in at least one of the models except race. W-3 supplementation showed efficacy on HDLSMALL among those who consumed w-3 + statins with a reduction of 2,211 mg /dL and cost-effectiveness R$ 109.31 per mg/dL for 2 months of treatment. CONCLUSION: The treatment with 1.8g of fish oil isolated or associated with statins in primary intervention did not show significant effects on changes in lipid parameters except HDLSMALL of interventions associated with statins. Therefore it was not cost-effective in reducing cardiovascular risk factors. Due to the existence of controversies about its potential effects, it is suggested that clinical trials use more robust statistical methods to assess the net impact of supplementation.
477

La fonction protectrice des acides gras oméga-3 dans la neuroinflammation et les comportements anxio-dépressifs induits par l’obésité et l’implication du récepteur GPR120

Demers, Geneviève 01 1900 (has links)
No description available.
478

Impact de la forme moléculaire et supramoléculaire de vectorisation des acides gras polyinsaturés n-3 sur leur biodisponibilité : étude physico-chimique et in vivo chez le rat / Influence of the molecular and supramolecular form of targeting of n-3 polyunsaturated fatty acids on their bioavailability : physicochemical and in vivo studies in rats

Sehl, Anthony 15 May 2019 (has links)
Les dernières données de consommation alimentaire de la population française démontrent que les apports nutritionnels en acide eicosapentaénoïque (EPA) et en acide docosahexaénoïque (DHA) sont nettement inférieurs aux recommandations fixées par l’Agence nationale de sécurité sanitaire, de l’alimentation, de l’environnement et du travail (ANSES). Compte tenu de leurs rôles physiologiques, l’amélioration de leur biodisponibilité est devenue une priorité nutritionnelle. La maitrise des formes de vectorisation des acides gras polyinsaturés à longue chaine de la série n-3 (AGPI-LC n-3) représente une piste d’intérêt afin de répondre à cette problématique. C’est dans ce contexte que s’inscrit ce travail de thèse, visant à étudier l’influence de la forme moléculaire (phospholipides (PL) vs triglycérides (TG)) et/ou supramoléculaire (phase continue, émulsion, liposomes) de vectorisation des AGPI-LC n-3 sur leur devenir métabolique.La démarche expérimentale adoptée a consisté, dans un premier temps, à caractériser les différentes formes de vectorisation des AGPI-LC n-3 par un couplage de méthodes d’analyse physico-chimiques (microscopie optique, granulométrie, mesure des produits primaires et secondaires d’oxydation, lipolyse enzymatique). Les données obtenues ont permis de poser des hypothèses mécanistiques pour l’étude de la biodisponibilité chez le rat. Ainsi, dans un deuxième temps, l’étude in vivo a permis d’aborder (1) l’absorption intestinale des acides gras (AG) suite à un apport en bolus de lipides et (2) l’accrétion tissulaire suite à un régime de 8 semaines.Les résultats indiquent que la forme moléculaire de vectorisation des AGPI-LC n-3 (TG marins vs PL marins, en phase continue) n’influence pas leur absorption intestinale mais plutôt leur incorporation dans les lipides lymphatiques, principaux transporteurs des AG alimentaires dans l’organisme. A l’inverse, la structuration des PL marins en milieu aqueux (émulsion ou liposomes), permet d’améliorer l’absorption de l’EPA et du DHA, de façon spécifique à la nature de la structuration supramoléculaire. Les résultats de l’accrétion tissulaire montrent qu’au terme des 8 semaines de régime, l’enrichissement tissulaire en AGPI-LC n-3 s’effectue de façon différente selon leur forme moléculaire de vectorisation. Ainsi, la consommation de TG marins favorise l’incorporation des AGPI-LC n-3 dans les lipides hépatiques, alors que la supplémentation des régimes en PL marins permet d’orienter le DHA vers le cerveau et la rétine.L’ensemble de ces résultats montre que le choix de la forme moléculaire de vectorisation des AGPI-LC n-3 (PL vs TG) peut être un moyen d'orienter leur incorporation tissulaire, alors que leur structuration supramoléculaire (émulsion ou liposomes), une stratégie pour moduler leur absorption intestinale. / The latest data from the cross-sectional national French dietary study show that dietary intakes of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are significantly lower than those recommended by the French Agency for Food, Environmental and Occupational Health & Safety (ANSES). Considering their physiological roles, improving their dietary intake has became a nutritional priority. The control of the different forms of n-3 long chain polyunsaturated fatty (n-3 LC-PUFA) intake represents an interesting way to address this issue. In this context, this thesis aims at studying the influence of the molecular form (phospholipids (PL) vs triglycerides (TG)) and/or supramolecular form (continuous phase, emulsion, liposomes) of n-3 LC-PUFA towards their bioavailability.The experimental approach consisted in characterizing the different forms of n-3 LC-PUFAs by coupling various physicochemical methods (optical microscopy, granulometry, measurement of primary and secondary oxidation products, enzymatic lipolysis). The data obtained made it possible to propose some mechanistic hypothesis for the bioavailability studies conducted in rat. Thus, in a second step, the in vivo study made addresses (1) the intestinal absorption of fatty acids following a single dose of lipids and (2) the lipid tissue accretion following an 8-week diet.The data obtained from the intestinal absorption study indicate that the molecular form of n-3 LC-PUFA targeting (marine TG vs marine PL, in continuous phase) does not influence their intestinal absorption but rather their incorporation into lymphatic lipids, which are the main carriers for dietary fatty acids in the organism. Conversely, structuring marine PL (emulsion or liposomes) improves the EPA and DHA absorption, but differently according to the supramolecular form. The results concerning tissue accretion show that, after 8-week diet, the tissue enrichment in n-3 LC-PUFA is different according to the molecular form of targeting. The consumption of marine TG favours the incorporation of n-3 LC-PUFA into hepatic lipids, while the supplementation of diets with marine PL targets DHA preferentially to brain and retina.All these results show that the molecular form of targeting (PL vs TG) of n-3 LC-PUFA can be a way for managing their tissue incorporation, whereas the supramolecular organization (emulsion or liposomes) can be envisaged to monitor their intestinal absorption.
479

Suplementação alimentar com óleo de peixe reduz a expressão da NADPH oxidase e aumenta a expressão da SOD1 e SOD2 em ilhotas pancreáticas de ratos. / Fish oil supplemented diet reduces NAD(P)H oxidase expression and increases SOD-1 and SOD2 expression in rat pancreatic islets.

Lucena, Camila Ferraz 21 September 2012 (has links)
A secreção de insulina é estimulada pela glicose, porém os ácidos graxos (AG) podem influenciar o processo secretório. A oxidação de AG é importante para a estimulação da secreção de insulina por aumentar o ATP, porém, existem vias dependentes e independentes de ATP. Os AG <font face=\"Symbol\">w-3 interferem em processos fisiológicos e na composição e função da membrana plasmática, promovendo potente ação anti-inflamatória. Considerando a importante relação da NAD(P)H oxidase com a secreção de insulina, o estudo das alterações induzidas pela suplementação com AG <font face=\"Symbol\">w-3 sobre o conteúdo de superóxido (O2<font face=\"Symbol\">&#183;) e a expressão da NAD(P)H oxidase, é importante para a compreensão da fisiologia das células <font face=\"Symbol\">b-pancreáticas. Neste estudo, o grupo suplementado apresentou redução do conteúdo de O2<font face=\"Symbol\">&#183;, redução da expressão das subunidades da NAD(P)H oxidase e aumento na expressão da superóxido dismutase (SOD1 e 2), quando comparado ao grupo controle. Embora desconhecido o mecanismo, este dado é relevante, pois pressupõe melhor regulação do estado redox durante a secreção de insulina. / Insulin secretion is stimulated by glucose (GSIS), but fatty acid (FA) may influence the secretory process. The oxidation of FA is important for the stimulation of insulin secretion by increasing the ATP, although there are dependent and independent ATP pathways. The <font face=\"Symbol\">w-3 FA change physiological processes, and affect the composition and function of the plasma membrane, promote potent anti-inflammatory action. Considering the important relationship of NAD(P)H oxidase with insulin secretion, the study of changes induced by supplementation with <font face=\"Symbol\">w-3 FA on the superoxide (O2<font face=\"Symbol\">&#183;) content, and expression of NAD(P)H oxidase, becomes of great importance for understanding the pancreatic <font face=\"Symbol\">b cells physiology. In this study, the group supplemented with <font face=\"Symbol\">w-3 FA showed a reduction of the O2<font face=\"Symbol\">&#183; content, reduced expression of NAD(P)H oxidase subunits, and increased the expression of the enzyme superoxide dismutase (SOD 1 and 2), compared to control. Although unknown the mechanism, this data is relevant, because it represents better regulation of the redox state during GSIS .
480

Aplicação de planejamento fatorial na oxidação de óleos contendo diferentes tipos de ácidos graxos ômega 3 / The use of factorial design to evaluate the oxidation of oils containing differents types of omega 3 fatty acids.

Agnes Dias Fabiano, Thamyris 27 September 2017 (has links)
Óleos contendo alta proporção de ácidos graxos ômega-3 (n-3 FA) têm sido aplicados na formulação de alimentos ou comercializados como suplementos, com a finalidade de reduzir o risco cardiovascular, principalmente devido aos seus efeitos hipotriglicêmicos e anti-inflamatórios. No entanto, a susceptibilidade à oxidação dos n-3 FA é elevada, levando à formação de vários produtos secundários, incluindo alguns tóxicos e potencialmente aterogênicos. Por esta razão, compostos naturais com propriedades antioxidantes têm sido investigados com o objetivo de melhorar a estabilidade oxidativa dos óleos com alta proporção de n-3 FA. Neste estudo, avaliou-se a capacidade antioxidante de dois compostos naturais (ácido sinápico e hidrato de rutina) utilizando-se um modelo acelerado para oxidar os óleos. Foram combinados cinco indutores (Temperatura; Ferro- Fe2+; 2,2\'-Azobis dicloridrato de 2-amidinopropano - AAPH; ascorbil palmitato - AP e 2,2\'-azobis -2,4-dimetilvaleronitrilo - AMVN) em um delineamento fatorial (25-1) com ½ fração de \"resolução V\" para acelerar a oxidação de três óleos (linhaça, Echium e peixe) contendo diferentes fontes de n-3 FA: ácido &#945;-linolênico (ALA), ácido estearidônico (SDA) e ácido eicosapentaenóico (EPA) + ácido docosahexaenóico (DHA), respectivamente. Não houve diferença entre os marcadores de oxidação (LOOH e TBARS) estimados pelos modelos e os valores observados experimentalmente. Os indutores AMVN e Fe2+ foram os principais fatores responsáveis pelo aumento da concentração de TBARS. Os valores dos marcadores oxidativos obtidos 48 h após a indução foram semelhantes ou superiores àqueles observados nas amostras oxidadas a 60°C por 15 dias, sendo ambos maiores que os valores observados nas amostras de óleo frescas. Entre os compostos voláteis formados pela oxidação de diferentes fontes de n-3 FA, (E, E) 2,4 -heptadienal, (E, E) 2,4-decadienal, decanal, undecanal e (E) -2-undecenal foram identificados em todas as amostras, podendo ser utilizados como marcadores oxidativos mais específicos. Utilizando o modelo de oxidação acelerada, o hidrato de rutina melhorou a estabilidade oxidativa do óleo de peixe, provavelmente devido à presença de grupos catecol em sua estrutura química. Este estudo contribuiu para que ensaios mais rápidos fossem realizados na avaliação do efeito antioxidante de novas moléculas aplicadas em óleos funcionais comestíveis. / Oils containing a high proportion of omega-3 fatty acids (n-3 FA) have been used in the formulation of foods or sold as supplements, aiming to reduce cardio-vascular risks, mainly due to their hypotriglycemic and anti-inflammatory effects. However, n-3 FA are highey susceptible to oxidation, leading to the formation of several products, including some toxic and potentially atherogenic. For this reason, natural products with antioxidant properties have been investigated to improve the oxidative stability of oils with a high proportion of n-3 FA. This study evaluated the antioxidant capacity of two natural compounds (sinapic acid and rutin hydrate), using an accelerated model to oxidize the oils. Five inducers were combined (Temperature, Iron-Fe2+, 2,2\'-Azobis (2-amidinopropane) dihydrochloride-AAPH, Ascorbyl palmitate-AP and 2,2\'-azobis-2,4-dimethylvaleronitrile-AMVN) in a factorial design (25-1) ½ fraction of \"resolution V\" to accelerate the oxidation of three oils (flaxseed, Echium and fish) containing different sources of n-3 FA: &#945;-linolenic acid (ALA), stearidonic acid (SDA) and eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA), respectively. There was no difference between the oxidation markers (LOOH and TBARS) estimated by the regression models and the values experimentally observed. The inducers AMVN and Fe2+ were the main factors responsible for the increase of TBARS concentration. The values of the oxidation markers obtained 48h after the induction were similar to or higher than those obtained when the samples were oxidized at 60°C for 15 days, both being more elevated than the values observed in the fresh oils. Among the volatile compounds formed by the oxidation of different sources of n-3 FA, (E, E) 2,4-heptadienal, (E, E) 2,4-decadienal, decanal, undecanal and (E)-2-undecenal were identified in all samples, and could be used as more specific oxidation markers. Using the accelerated model, rutin hydrate improved the oxidative stability of fish oil, probably due to the presence of catechol groups in its chemical structure. This study showed that faster anays could be performed to evaluate the antioxidant effect of new molecules applied on edible functional oils.

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