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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.
11

Increasing Dietary Linoleic Acid Does Not Increase Tissue Arachidonic Acid Content in Adults Consuming Western- Type Diets

Rett, Brian 01 May 2011 (has links)
Linoleic acid, with a DRI of 12-17g/d, is the most highly consumed polyunsaturated fatty acid in the Western diet and is found in virtually all commonly consumed foods. The concern with dietary linoleic acid, being the metabolic precursor of arachidonic acid, is its consumption may enrich tissues with arachidonic acid and contribute to chronic and overproduction of bioactive eicosanoids. However, no systematic review of human trials regarding linoleic acid consumption and subsequent changes in tissue levels of arachidonic acid has been undertaken. In this study, we reviewed the human literature that reported changes in dietary linoleic acid and its subsequent impact on changing tissue arachidonic acid in erythrocytes and plasma/serum phospholipids. We identified, reviewed, and evaluated all peer-reviewed published literature presenting data outlining changes in dietary linoleic acid in adult human clinical trials that reported changes in phospholipid fatty acid composition (specifically arachidonic acid) in plasma/serum and erythrocytes within the parameters of our inclusion/exclusion criteria. Decreasing dietary linoleic acid up to 90% was not significantly correlated with changes in tissue arachidonic acid levels (p=0.39). Similarly, when dietary linoleic acid levels were increased six fold, no significant correlations with tissue arachidonic acid levels were observed (p=0.72). However, there was a positive relationship between dietary gamma-linolenic acid and arachidonic acid on changes in tissue arachidonic levels. Our results do not support the concept that modifying current intakes of dietary linoleic acid has an effect on changing tissue levels of arachidonic acid in adults consuming Western-type diets.
12

Modulation of Lipopolysaccharide-Stimulated Adipokine Synthesis and Secretion by n-3 and n-6 Polyunsaturated Fatty Acids

Cranmer-Byng, Mary 01 May 2013 (has links)
Dysregulation of adipokines in obese adipose tissue contributes to inflammation and insulin resistance. Fatty acids and lipopolysaccharide (LPS) can modulate adipokine secretion, however, less is known about their effects in combination. Long-chain n-3 polyunsaturated fatty acids (PUFA) exert anti-inflammatory effects and less is known about other n-3 and n-6 PUFA, which are more prevalent in the typical diet. Co-incubation of 3T3-L1 adipocytes with LPS and long-chain n-3 PUFA decreased LPS-induced secreted MCP-1 protein. n-6 PUFA arachidonic acid and LPS synergistically increased MCP-1 and IL-6 secreted proteins. Plant-derived PUFA were relatively neutral stimuli. mRNA expression results suggest potential roles for G protein-coupled receptor 120 and toll-like receptor 2 in mediating the effects of long-chain n-3 PUFA and arachidonic acid, respectively. Overall, this thesis suggests that both n-3 and n-6 PUFA are important factors to consider in the development of nutritional strategies for improving adipose tissue inflammation associated with obesity. / NSERC CGS, Ontario Graduate Scholarship
13

Camargo Guarnieri: uma análise das sonatinas n.3 e n.6 para piano

Ribas, Geraldo Majela Brandão January 2002 (has links)
O presente trabalho pretende analisar as fugas das Sonatinas nº3 e nº6 para piano de Camargo Guarnieri, através de uma análise estilística e tendo em vista os procedimentos utilizados pelo compositor especificamente no tratamento da fuga como técnica composicional. Guarnieri compôs 8 sonatinas para piano escritas entre 1928 e 1982, período que abrange grande parte da vida criativa do compositor. A análise das duas as fugas enfocará cinco parâmetros, conforme o esquema analítico de Jan LaRue: Som, Harmonia, Melodia, Ritmo e Crescimento. Através desses parâmetros, verificaremos como se desenvolvem estruturalmente as fugas, destacando os aspectos mais importantes que caracterizarão o discurso musical desenvolvido pelo compositor.
14

Camargo Guarnieri: uma análise das sonatinas n.3 e n.6 para piano

Ribas, Geraldo Majela Brandão January 2002 (has links)
O presente trabalho pretende analisar as fugas das Sonatinas nº3 e nº6 para piano de Camargo Guarnieri, através de uma análise estilística e tendo em vista os procedimentos utilizados pelo compositor especificamente no tratamento da fuga como técnica composicional. Guarnieri compôs 8 sonatinas para piano escritas entre 1928 e 1982, período que abrange grande parte da vida criativa do compositor. A análise das duas as fugas enfocará cinco parâmetros, conforme o esquema analítico de Jan LaRue: Som, Harmonia, Melodia, Ritmo e Crescimento. Através desses parâmetros, verificaremos como se desenvolvem estruturalmente as fugas, destacando os aspectos mais importantes que caracterizarão o discurso musical desenvolvido pelo compositor.
15

Camargo Guarnieri: uma análise das sonatinas n.3 e n.6 para piano

Ribas, Geraldo Majela Brandão January 2002 (has links)
O presente trabalho pretende analisar as fugas das Sonatinas nº3 e nº6 para piano de Camargo Guarnieri, através de uma análise estilística e tendo em vista os procedimentos utilizados pelo compositor especificamente no tratamento da fuga como técnica composicional. Guarnieri compôs 8 sonatinas para piano escritas entre 1928 e 1982, período que abrange grande parte da vida criativa do compositor. A análise das duas as fugas enfocará cinco parâmetros, conforme o esquema analítico de Jan LaRue: Som, Harmonia, Melodia, Ritmo e Crescimento. Através desses parâmetros, verificaremos como se desenvolvem estruturalmente as fugas, destacando os aspectos mais importantes que caracterizarão o discurso musical desenvolvido pelo compositor.
16

Adsorbuotų ant metalo paviršiaus monosluoksnių su piridinio funkcine grupe struktūros ir sąveikos su tirpalo komponentais tyrimas virpesinės spektroskopijos metodais / Vibrational spectroscopic study on the structure and interaction with solution components of monolayers with pyridinium functional group adsorbed on metal surface

Matulaitienė, Ieva 06 January 2014 (has links)
Savitvarkiai monosluoksniai suteikia metalų paviršiams norimas savybes ir plačiai taikomi elektronų pernašos tyrimuose, konstruojant (bio)jutiklius, biotechnologinius bei fotoelektroninius procesus. Teigiamo krūvio monosluoksniai naudojami kuriant anijonų jutiklius ir (bio)technologinius procesus su adsorbuotomis neigiamo krūvio makromolekulėmis. Darbe buvo susintetinta bifunkcinė molekulė su galinėmis tiolio ir piridinio grupėmis, suformuotas monosluoksnis ir ištirtos jo struktūrinės ir funkcinės savybės. Pagrindiniai darbo tikslai buvo ištirti N-(6-merkapto)heksilpiridinio (MHP) adsorbuoto ant Au ir Ag elektrodų struktūrą ir nustatyti monosluoksnio sąveikos su neorganiniais anijonais, dodecilsulfato anijonu ir grafeno oksidu dėsningumus. Naudojant paviršiaus sustiprintos Ramano spektroskopijos, kvantų chemijos skaičiavimo ir izotopinio pakeitimo metodus nustatyti MHP struktūros ir orientacijos elektrodo atžvilgiu Ramano sklaidos žymenys. Tiriant juostų intensyvumo priklausomybes nuo potencialo ir žadinančios spinduliuotės bangos ilgio parodyta, kad Au/MHP sistemoje pasireiškia krūvio pernešimo Ramano spektrų stiprinimo mechanizmas. Nustatyta, kad adsorbuotų neorganinių anijonų pilnai simetrinio virpesio dažnis sumažėja lyginant su tirpalo spektru ir tas pokytis koreliuoja su Gibso dehidracijos energija. Parodyta, kad MHP pritraukia grafeno oksidą. Nustatyta, kad grafeno oksido C-C ryšio ilgis ir elektroninė struktūra gali būti keičiama, keičiant potencialą. / Self-assembled monolayers provide possibility of changing metal surface properties in controllable manner and are widely used in studies of electron transfer, construction of (bio)sensors, and biotechnological and photoelectronic processes. Positively charged monolayers are valuable in development of sensors for anions and (bio)technological processes with adsorbed negatively charged macromolecules. In this work the structural and functional properties of monolayer formed from synthesized molecule with terminal thiol and pyridinium groups have been studied. The main tasks were to assess the structure of N-(6-mercapto)hexylpyridinium (MHP) on Ag and Au electrodes, and to determine the peculiarities of interaction with inorganic anions, dodecylsulfate, and graphene oxide. Based on surface enhanced Raman spectroscopy (SERS), quantum chemical calculations, and isotopic substitution studies, the Raman marker bands for structure and orientation of MHP have been evaluated. Dependence of SERS intensity on potential and excitation wavelength has revealed the operation of charge transfer Raman enhancement mechanism. It was found that the frequency of symmetric stretching mode of adsorbed ions decreases comparing with solution value and the extent of the shift correlates with the Gibbs dehydration energy. Adsorption of graphene oxide at MHP monolayer has been demonstrated. The electronic structure and length of C-C bonds of graphene oxide was found to be altered by the potential.
17

Vibrational spectroscopic study on the structure and interaction with solution components of monolayers with pyridinium functional group adsorbed on metal surface / Adsorbuotų ant metalo paviršiaus monosluoksnių su piridinio funkcine grupe struktūros ir sąveikos su tirpalo komponentais tyrimas virpesinės spektroskopijos metodais

Matulaitienė, Ieva 06 January 2014 (has links)
Self-assembled monolayers provide possibility of changing metal surface properties in controllable manner and are widely used in studies of electron transfer, construction of (bio)sensors, and biotechnological and photoelectronic processes. Positively charged monolayers are valuable in development of sensors for anions and (bio)technological processes with adsorbed negatively charged macromolecules. In this work the structural and functional properties of monolayer formed from synthesized molecule with terminal thiol and pyridinium groups have been studied. The main tasks were to assess the structure of N-(6-mercapto)hexylpyridinium (MHP) on Ag and Au electrodes, and to determine the peculiarities of interaction with inorganic anions, dodecylsulfate, and graphene oxide. Based on surface enhanced Raman spectroscopy (SERS), quantum chemical calculations, and isotopic substitution studies, the Raman marker bands for structure and orientation of MHP have been evaluated. Dependence of SERS intensity on potential and excitation wavelength has revealed the operation of charge transfer Raman enhancement mechanism. It was found that the frequency of symmetric stretching mode of adsorbed ions decreases comparing with solution value and the extent of the shift correlates with the Gibbs dehydration energy. Adsorption of graphene oxide at MHP monolayer has been demonstrated. The electronic structure and length of C-C bonds of graphene oxide was found to be altered by the potential. / Savitvarkiai monosluoksniai suteikia metalų paviršiams norimas savybes ir plačiai taikomi elektronų pernašos tyrimuose, konstruojant (bio)jutiklius, biotechnologinius bei fotoelektroninius procesus. Teigiamo krūvio monosluoksniai naudojami kuriant anijonų jutiklius ir (bio)technologinius procesus su adsorbuotomis neigiamo krūvio makromolekulėmis. Darbe buvo susintetinta bifunkcinė molekulė su galinėmis tiolio ir piridinio grupėmis, suformuotas monosluoksnis ir ištirtos jo struktūrinės ir funkcinės savybės. Pagrindiniai darbo tikslai buvo ištirti N-(6-merkapto)heksilpiridinio (MHP) adsorbuoto ant Au ir Ag elektrodų struktūrą ir nustatyti monosluoksnio sąveikos su neorganiniais anijonais, dodecilsulfato anijonu ir grafeno oksidu dėsningumus. Naudojant paviršiaus sustiprintos Ramano spektroskopijos, kvantų chemijos skaičiavimo ir izotopinio pakeitimo metodus nustatyti MHP struktūros ir orientacijos elektrodo atžvilgiu Ramano sklaidos žymenys. Tiriant juostų intensyvumo priklausomybes nuo potencialo ir žadinančios spinduliuotės bangos ilgio parodyta, kad Au/MHP sistemoje pasireiškia krūvio pernešimo Ramano spektrų stiprinimo mechanizmas. Nustatyta, kad adsorbuotų neorganinių anijonų pilnai simetrinio virpesio dažnis sumažėja lyginant su tirpalo spektru ir tas pokytis koreliuoja su Gibso dehidracijos energija. Parodyta, kad MHP pritraukia grafeno oksidą. Nustatyta, kad grafeno oksido CC ryšio ilgis ir elektroninė struktūra gali būti keičiama, keičiant potencialą.
18

Influência dos diferentes ácidos graxos da dieta sobre um modelo animal de mania induzido por anfetamina em ratos / Influence different fatty acid of the diet on an animal model of mania induced by amphetamine in rats

Trevizol, Fabíola 22 April 2010 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Fatty acids (FA) are constituent important of the neuronal phospholipids membranes and they carry out important functions in the development and function of the brain During the last decades changes were observed in the feeding habits of western countries, with an increase of the trans FA and omega-6 (n-6) and detriment of omega-3 fatty acids (n-3) consumption, contributing to increase the oxidative stress (OS) generation and development of neuropsychiatric disorders. The influence of FA supplementation containing n-6 (soybean oil-SO), trans (hydrogenated vegetable fat-HVF) and n-3 (fish oil-FO) on behavioral parameters and OS were studied in an animal model of mania. Rats were orally treated for 8 weeks with suspensions of SO, HVF and FO in place of drinking water, and treated with seven daily administrations of amphetamine (AMPH-mg/kg, ip) or vehicle, in the last week of oral treatment. Locomotor activity, vitamin C (VIT C) levels, protein oxidation and mitochondrial slices in striatum and cortex were evaluated. HVF supplemented rats showed an increase in the locomotor activity, higher levels of carbonyl protein in the cortex, and lower mitochondrial viability in the striatum and cortex, showing harmful effects per se. AMPH treatment increased the locomotor activity of all groups, but this effect showed greater intensity in the rats orally treated with HVF (456%). Similarly, AMPH increased the carbonyl protein levels in striatum (39.5%) and cortex (78%) of the animals orally treated with HVF, while SO and FO prevented it in the cortex. AMPH treatment decreased the mitochondrial viability in cortex and striatum of supplemented rats with all the FA; however the HVF group showed greater damage (46 and 44% of viability in the striatum and cortex, respectively). AMPH reduced the VIT C plasma levels of the HVF and SO groups (22.5 and 22.4% respectively), and this antioxidant parameter has not been changed in the FO treated rats. Here, we suggest that the trans FA contained in the HVF may increase the oxidative damages per se, leaving the rats more vulnerable to AMPH damage. FA n-3 contained in the FO showed subtle protecting effects, which were observed by preservation of the VIT C levels and lower levels of carbonyl protein in the cortex. Further studies should be conducted to evaluate the influence of the trans fatty acids consumption on neuronal activity, and consequently on the susceptibility to psychiatric disorders development among them the bipolar disorder. / Ácidos graxos (AG) são constituintes importantes das membranas fosfolipídicas neuronais e desempenham importantes funções no desenvolvimento e funcionamento do cérebro. Durante as últimas décadas foram observadas mudanças nos hábitos alimentares de países ocidentais, com aumento do consumo de AG trans e ômega-6 (n-6) em detrimento do consumo de ácidos graxos ômega-3 (n-3), cujas conseqüências podem estar relacionadas a um aumento dos danos oxidativos, facilitando o desenvolvimento de doenças neuropsiquiátricas. A influência da suplementação com AG n-6 (óleo de soja-OS), trans (gordura vegetal hidrogenada-GVH) e n-3 (óleo de peixe-OP) sobre parâmetros comportamentais e de estresse oxidativo (EO) foram estudados em um modelo animal de mania. Ratos tratados oralmente com suspensões de OS, GVH e OP, junto à água de beber durante 8 semanas, receberam nos últimos sete dias administrações diárias de anfetamina (ANF-4mg/kg, ip) ou veículo. Atividade locomotora, os níveis de vitamina C (VIT C) plasmático, marcadores de oxidação de proteínas e a viabilidade de fatias do estriado e córtex foram determinados. Animais suplementados com GVH mostraram um aumento da atividade locomotora, maior nível de proteínas carbonil no córtex, e menor viabilidade nas fatias do estriado e córtex, demonstrando efeitos prejudiciais per se. O tratamento com ANF aumentou a atividade locomotora dos animais de todos os grupos experimentais, porém este efeito mostrou maior intensidade nos animais que receberam a suplementação com GVH (456%). Semelhante, a ANF aumentou a carbonilação de proteínas no estriado (39.5%) e córtex (78%) dos animais suplementados com GVH, enquanto OS e OP preveniram o dano causado pela ANF no córtex. O tratamento com ANF diminuiu a viabilidade mitocondrial nos tecidos cerebrais de todos os grupos, entretanto o grupo suplementado com GVH apresentou maiores danos (46 e 44% de viabilidade no estriado e córtex, respectivamente). A ANF diminuiu os níveis de VIT C no plasma dos animais suplementados com OS e GVH (22.5 e 22.4%, respectivamente), e este parâmetro antioxidante não foi alterado nos ratos tratados com OP. Os resultados do presente estudo sugerem que os ácidos graxos trans presentes na GVH podem aumentar os danos oxidativos per se, deixando os animais mais expostos aos danos da ANF. A suplementação com ácidos graxos n-3 presentes no OP mostraram efeitos protetores sutis, representados pela preservação dos níveis de VIT C plasmático e menor oxidação de proteínas no córtex. Maiores estudos devem ser realizados para determinar a influência do consumo de ácidos graxos trans sobre a atividade neuronal, e conseqüentemente sobre a suscetibilidade para o desenvolvimento de desordens psiquiátricas entre estas, o transtorno bipolar.
19

Allometric scaling of dietary linoleic acid on changes in tissue arachidonic acid using human equivalent diets in mice

Weldon, Kylie A 01 May 2011 (has links)
The ability to extrapolate nutritional intervention data from experimental rodent models to humans requires standardization of dietary design. The inability to translate the level of nutrients from animal models to humans has contributed to contradictory findings between species. It is hypothesized that dietary linoleic acid (LA) promotes chronic and acute diseases by enriching tissues with arachidonic acid (AA), its downstream metabolite. However, levels of LA in rodent diets are notoriously erratic making interspecies comparisons unreliable. Therefore, the ability to extrapolate the biological effects of dietary LA from experimental rodents to humans necessitates an allometric scaling model that is rooted within a human equivalent context. To determine the physiological effect of dietary LA on tissue AA, a mathematical model for extrapolating nutrients based on energy was designed to mimic human equivalent doses. C57BL/6J mice were divided into 9 groups fed a background diet equivalent to that of the US diet (including LA, ALA, AA, EPA, DHA) with supplemental doses of LA (up to 2.3x) or AA (up to 5x). Changes in the phospholipid fatty acid compositions were monitored in plasma and erythrocytes and compared to data from humans supplemented with equivalent doses of LA or AA. Increasing dietary LA had little effect on tissue AA, while supplementing diets with AA significantly increased tissue AA levels, recapitulating results from human trials. Thus, interspecies comparisons for dietary LA between rodents and humans can be achieved when rodents are provided human equivalent doses based on differences in metabolic activity as defined by energy consumption.
20

Establishing the anti-cancer effects of unsaturated fatty acids and a novel oil on human breast cancer cells

Yu, Howe-Ming Unknown Date
No description available.

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