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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.
31

ALGAE OR YEAST SUPPLEMENTATION FOR LACTATING DAIRY COWS

Weatherly, Maegan E 01 January 2015 (has links)
The objective of the first study was to quantify the effects of feeding Schizochytrium sp. microalgae (SP-1, Alltech, Inc., Nicholasville, KY) on milk fat and DHA content. Eight cows were fed: 0, 100, 300, or 600 g of algae per day. Fat percentage was greater (P < 0.05) for cows on treatments 0 g and 100 g than for cows on treatments 300 g and 600 g (P < 0.05). Docosahexaenoic acid in milk was greater for cows on treatment 300 and 600 than for cows on treatment 0 and 100 (P < 0.05). The objective of the second study was to assess yeast supplementation effects on high and low forage dairy cow diets. Four cows were assigned to 1 of 4 treatments: 1) low forage (LF), 2) low forage with 10 g/d yeast (Yea-Sacc®; Alltech Inc., Nicholasville, KY; LFY), 3) high forage (HF), or 4) high forage with 10 g/d yeast (HFY). Only rumination time and DMI were influenced by treatment (P < 0.01). Dry matter intake was 17.05, 13.41, 19.44, and 20.29 ± 1.40 kg/d and rumination time was 442.88, 323.09, 433.34, and 475.50 ± 21.93 min/d for cows on the LF, LFY, HF, and HFY treatments, respectively.
32

Evaluation of Conventional and Novel Dietary Strategies to Promote Intake of Omega-3 Highly Unsaturated Fatty Acids

Patterson, Ashley January 2012 (has links)
Intakes of the highly unsaturated fatty acids (HUFA, ≥20 Carbons, ≥3 double bonds) eicosapentaenoic acid (20:5n-3; EPA) and docosahexaenoic acid (22:6n-3, DHA) greater than 0.25 g/d are currently recommended for health benefits. Targets for omega-3 blood biomarkers have also been proposed based on associations with protection against coronary heart disease mortality. The relationship between diet intakes and blood biomarkers is not well defined, particularly differences between men and women. North American intakes and blood biomarkers of EPA and DHA are typically below recommendations and targets. To address this disparity, adherence to dietary advice strategies to increase EPA + DHA intake was investigated over one year. Adherence was sustained up to 12 weeks and long-term adherence was well characterized by the % of DHA in erythrocytes. For women, n-3 HUFA blood biomarkers increased following nutraceutical or combined strategy dietary advice but not seafood or functional food advice. To assist in the assessment of EPA + DHA intakes, food sources of EPA and DHA in Canada were incorporated into a semi-quantitative, nutrient-specific food frequency questionnaire (FFQ) and validated. The FFQ is an adequate tool for estimating habitual EPA and DHA intake and ranking Canadian adults by their intakes. The blood biomarker response to recommended intakes of 0.25, 0.5 and 1 g/d EPA + DHA was also characterized in adult men and women. Blood n-3 HUFA biomarkers increased in a dose-dependent manner and aligned with blood targets associated with primary cardiac arrest risk reduction. Sex differences in the DHA:EPA ratio in blood observed with low intakes at baseline disappeared following 0.25 g/d EPA + DHA. These findings are applicable towards informing achievable dietary guidelines for EPA + DHA intake and improving measurement of EPA + DHA intake in relation to blood n-3 HUFA biomarkers.
33

Isolation and characterization of Aurantiochytrium species useful for ω-3 fatty acids production / オメガ3脂肪酸生産に有用なAurantiochytrium属微生物の単離と解析

Wu, Chang-Yu 23 March 2022 (has links)
京都大学 / 新制・課程博士 / 博士(農学) / 甲第23957号 / 農博第2506号 / 新制||農||1092(附属図書館) / 学位論文||R4||N5392(農学部図書室) / 京都大学大学院農学研究科応用生命科学専攻 / (主査)教授 小川 順, 教授 阪井 康能, 教授 栗原 達夫 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM
34

The independent effects of purified EPA and DHA supplementation on cardiovascular risk in treated-hypertensive type 2 diabetic individuals /

Woodman, Richard John. January 2003 (has links)
Thesis (Ph.D.)--University of Western Australia, 2003.
35

The role of arachidonic and docosahexaenoic acid in the alteration of hepatic fuel utilization throughout the perinatal period of the pig

Campbell, Jenny A., January 2009 (has links)
Thesis (M.S.)--Ohio State University, 2009. / Title from first page of PDF file. Includes bibliographical references (p. 85-94).
36

Differential effects of arachidonic acid and docosahexaenoic acid on cell biology and osteoprotegerin synthesis in osteoblast-like cells

Coetzee, Magdalena. January 2005 (has links)
Thesis (PhD.(Physiology)--Faculty of Health Sciences)-University of Pretoria, 2005. / Summary in English and Afrikaans. Also available on the Internet via the World Wide Web.
37

Estudos dos produtos da oxidação não enzimática do ácido docosahexaenoico como possíveis biomarcadores para doenças neurodegenerativas / Study of Docosahexaenoic acid non-enzymatic oxidation products as biomarkers for neurodegenerative diseases

Priscilla Bento Matos Cruz Derogis 05 September 2014 (has links)
Os n-3 e n-6 são duas famílias de ácidos graxos poli-insaturados. Os ácidos graxos de cadeia longa como o ácido araquidônico (AA) e docosahexaenoico (DHA) apresentam importantes funções no desenvolvimento e funcionamento do cérebro. Os produtos de oxidação dos ácidos graxos poli-insaturados estão presentes ou aumentados ao longo do desenvolvimento de doenças neurodegenerativas. A caracterização de tais produtos é crítica para o estudo que busca entender o seu papel fisiopatológico no desenvolvimento de tais doenças. No presente trabalho, buscou-se o desenvolvimento de uma ferramenta analítica sensível e específica para a detecção e quantificação dos hidroperóxidos e hidróxidos do AA (HpETE e HETE), do seu precursor, o ácido linoleico (HpODE e HODE) e do DHA (HpDoHE e HDoHE). Estes hidroperóxidos foram sintetizados por fotooxidação e os hidróxidos correspondentes foram obtidos através da redução com o NaBH4. Os isômeros isolados foram caracterizados por LC-MS/MS. Os íons produto específicos de cada isômero foram escolhidos para a construção do método de monitoramento de reação selecionada (selected reaction monitoring - SRM) para a realização da análise quantitativa dos analitos de interesse. Cabe salientar que os dados obtidos poderão ser utilizados em bibliotecas de análise lipidômica e oxi-lipidômica pois serão essenciais para a identificação e quantificação dos analítos de interesse do presente estudo em diversas doenças. Utilizando o método padronizado, buscamos investigar o papel dos hidroperóxidos e hidróxidos do DHA, LA e AA em um modelo animal para a esclerose lateral amiotrófica (ELA), uma doença neurodegenerativa que acomete neurônios motores. Foi observado um aumento nos níveis de 13-HpODE, 9-HpODE e 12-HETE no córtex motor dos animais avaliados. Adicionalmente, foram observadas alterações nas taxas lipólica e lipogênica no tecido adiposo para os animais ELA em relação aos respectivos controles. Em conjunto, os dados apresentados no presente trabalho corroboram com os trabalhos da literatura que associam alteração dos níveis dos produtos de oxidação dos ácidos graxos poli-insaturados em doenças neurodegenerativas e o metabolismo energético alterado em ELA. Futuramente é necessária uma investigação mais ampla dos níveis dos hidroperóxidos e hidróxidos lipídicos em diferentes tecidos e do metabolismo lipídico, e os conhecimentos gerados poderão ser uma importante fonte de novas opções terapêuticas para os pacientes portadores de ELA. / The n-3 and n-6 are two olyunsaturated fatty acids families. The long chain fatty acids such as arachidonic (AA) and docosahexaenoic acid (DHA) have important roles in the development and function of the brain. Polyunsaturated fatty acids (PUFAs) oxidation products are present or increased during the progression of neurodegenerative diseases. The characterization of DHA oxidation products is critical to understand their roles in the development of such diseases. In the present study, we sought to develop a sensitive and specific analytical tool for the detection and quantification of AA hydroperoxides and hydroxides (HPETE and HETE), its precursor linoleic acid (HPODE and HODE) and DHA (HpDoHE and HDoHE). These hydroperoxides were synthesized by photooxidation and the corresponding hydroxides were obtained by reduction with NaBH4. The isolated isomers were characterized by LC-MS/MS, and unique and specific fragment ions were chosen to construct a selected reaction monitoring (SRM) method for the targeted quantitative analysis. It should be emphasized that the data obtained - in the form of lipidomics and oxy-lipidomics libraries - may be used to assist in several diseases. Using the standardized method, we investigated the role of hydroperoxides and hydroxides of DHA, LA and AA in an animal model of amyotrophic lateral sclerosis (ALS), a neurodegenerative disease that affects motor neurons. Increased levels of 13-HPODE, 9-HPODE and 12-HETE were observed in the animals motor cortex. Additionally, results show changes in lipogenic and lipolytic rates in adipose tissue for ALS animals when compared to their respective controls. Altogether, the data presented herein corroborate with the literature by linking altered levels of PUFAs oxidation products in neurodegenerative diseases with altered energetic metabolism in ALS. In the future, a more extensive investigation of the hydroperoxide and hydroxide level in different tissues as well as the lipid metabolism must be done, which could lead to new therapeutic options for ALS patients
38

Total Long-Chain n-3 Fatty Acid Intake and Food Sources in the United States Compared to Recommended Intakes: NHANES 2003–2008

Richter, Chesney K., Bowen, Kate J., Mozaffarian, Dariush, Kris-Etherton, Penny M., Skulas-Ray, Ann C. 27 September 2017 (has links)
The American Heart Association recommends consuming fish (particularly oily fish) at least two times per week, which would provide ae 0.5 g/day of eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) for cardiovascular disease risk reduction. Previous analyses indicate that this recommendation is not being met; however, few studies have assessed different ethnicities, subpopulations requiring additional n-3 fatty acid intake (i.e., children and pregnant and/or lactating women), or deciles of intake. Data from the National Health and Nutrition Examination Survey 2003-2008 was used to assess n-3 fatty acid intake from foods and supplements in the US population, according to age, sex, and ethnicity. A unique "EPA equivalents" factor, which accounts for potential conversion of shorter-chain n-3 fatty acids, was used to calculate total long-chain n-3 fatty acid intake. Data are reported for 24,621 individuals. More than 90% consumed less than the recommended 0.5 g/day from food sources (median = 0.11 g/day; mean = 0.17 g/day). Among the top 15% of n-3 fatty acid consumers, fish was the largest dietary contributor (71.2%). Intake was highest in men aged 20 years or more, and lowest in children and women who are or may become pregnant and/or are lactating. Among ethnicities, intake was lowest in Mexican-Americans. Only 6.2% of the total population reported n-3 fatty acid supplement use, and this did not alter median daily intake. Additional strategies are needed to increase awareness of health benefits (particularly among Mexican-Americans and women of childbearing age) and promote consumption of oily fish or alternative dietary sources to meet current recommendations.
39

Biological and Pathophysiological Roles of End-Products of DHA Oxidation

Yakubenko, Valentin P., Byzova, Tatiana V. 01 April 2017 (has links)
© 2016 Elsevier B.V. Background Polyunsaturated fatty acids (PUFA) are known to be present and/or enriched in vegetable and fish oils. Among fatty acids, n-3 PUFA are generally considered to be protective in inflammation-related diseases. The guidelines for substituting saturated fatty acids for PUFAs have been highly publicized for decades by numerous health organizations. Recently, however, the beneficial properties of n-3 PUFA are questioned by detailed analyses of multiple randomized controlled clinical trials. The reported heterogeneity of results is likely due not only to differential effects of PUFAs on various pathological processes in humans, but also to the wide spectrum of PUFA's derived products generated in vivo. Scope of review The goal of this review is to discuss the studies focused on well-defined end-products of PUFAs oxidation, their generation, presence in various pathological and physiological conditions, their biological activities and known receptors. Carboxyethylpyrrole (CEP), a DHA-derived oxidized product, is especially emphasized due to recent data demonstrating its pathophysiological significance in many inflammation-associated diseases, including atherosclerosis, hyperlipidemia, thrombosis, macular degeneration, and tumor progression. Major conclusions CEP is a product of radical-based oxidation of PUFA that forms adducts with proteins and lipids in blood and tissues, generating new powerful ligands for TLRs and scavenger receptors. The interaction of CEP with these receptors affects inflammatory response, angiogenesis, and wound healing. General significance The detailed understanding of CEP–mediated cellular responses may provide a basis for the development of novel therapeutic strategies and dietary recommendations.
40

The Effect of Docosahexaenoic Acid (DHA)-Containing Phosphatidylcholine (PC) on Liquid-Ordered and Liquid-Disordered Coexistence

Gu, Yongwen 05 August 2014 (has links)
Plasma membranes are essential to both the structure and function of mammalian cells. The first unifying paradigm of membrane structure, the Fluid Mosaic Model, is no longer considered adequate to describe the many non-homogeneous lipid structures that have been observed in both natural and model membranes over the past approximately thirty years. The field of membrane biophysics now appreciates that the complex mixture of different lipid species found in natural membranes produces a range of dynamic, laterally segregated, non-homogeneous structures which exist on time scales ranging from microseconds to minutes. When sphingomyelin (SM), POPC and cholesterol are all present in a bilayer there is wide range of compositional ratios where the bilayer consists of a coexistence between two fluid phases designated liquid ordered (lo) and liquid disordered (ld). The lo phase is cholesterol-rich phase characterized by relatively high molecular order and slow rotational and translational motion, while the ld phase generally has low molecular order and relatively rapid rotational and translational motion. The driving force for the formation of these two phases is the ability of cholesterol to form favorable van der Waals contacts with the two saturated acyl chains on PSM and the one saturated acyl chain on POPC. The ternary system is an important model system for examining the physical properties and functional implications of co-existing lo and ld phases. However, it does not include one of the most significant compositional variables found in many important mammalian membranes. Membranes in the nervous system contain high concentrations of the highly polyunsaturated fatty acid docosahexaenoic acid (DHA), which contains 22 carbons and 6 double bonds. A wide range of experimental evidence shows that DHA-containing phospholipids are important for optimal performance of a number of membrane signaling systems and membrane protein functions. The goal of this study is to determine how addition of a DHA-containing phospholipid, PDPC alters the biologically important lo and ld co-existence region.

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