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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.
121

Estudo dos óleos essenciais de espécies de Pelargonium (Geraniaceae) e de suplementos alimentares e compostos emagrecedores contendo 1,3-dimetilamilamina : uma abordagem química, antifúngica e forense

Santos, Maíra Kerpel dos January 2018 (has links)
A 1,3-dimetilamilamina (DMAA) é um estimulante que passou a ser adicionada aos suplementos alimentares e compostos emagrecedores a partir de 2006, sendo amplamente consumida por atletas e militares americanos. No entanto, após relatos de toxicidade a DMAA foi proibida por agências regulatórias do Brasil e Estados Unidos. Porém, mesmo após a sua proibição, a DMAA ainda pode ser encontrada em suplementos alimentares. A sua origem foi relacionada ao óleo essencial de Pelargonium graveolens, e, no entanto, inúmeros autores questionaram os resultados originais e a sua origem natural. Adicionalmente, os óleos essenciais de espécies de Pelargonium tiveram a sua atividade antimicrobiana reportada frente a bactérias e fungos. Assim, considerando os aspectos abordados, este trabalho teve como objetivo determinar a presença de DMAA nos óleos essenciais de Pelargonium spp. por GC-MS, DART-MS/MS e LC-MS/MS; assim como nas folhas das mesmas espécies, utilizando a extração por headspace, previamente otimizada, seguida de análise por GC-MS. Também se propôs a investigar a atividade antifúngica dos óleos essenciais de P. graveolens de diferentes origens e desenvolver uma formulação contendo uma nanoemulsão do óleo para o tratamento de candidíase vaginal. Por fim, teve como objetivo desenvolver metodologia de screening para avaliar a presença de DMAA e outros estimulantes em suplementos alimentares apreendidos, através de DART-MS/MS. Os resultados revelaram que a DMAA não está presente nos óleos essenciais de diferentes espécies de Pelargonium spp. obtidos por hidrodestilação, do Rio Grande do Sul. Após a otimização através de desenho experimental, a técnica de headspace provou ser eficaz na extração dos constituintes voláteis presentes nas folhas e, no entanto, a DMAA não foi detectada, assim como nos óleos essenciais comerciais de P. graveolens do Brasil, China, Egito, África do Sul, Albânia e Ilhas Reunião. Os óleos essenciais apresentaram atividade antifúngica frente às cinco espécies de Candida. Ainda, este efeito antifúngico apresentou melhores resultados com a nanoformulação contendo o óleo essencial. A análise de screening por DART-MS/MS se mostrou eficaz na detecção de DMAA, efedrina, sinefrina, cafeína, sibutramina e metilfenidato, em amostras de suplementos alimentares apreendidos, apresentando resultados positivos para todos os estimulantes. Com base nos resultados obtidos e nos objetivos propostos, verificou-se que mesmo após a 12 utilização de três técnicas analíticas distintas e uma nova alternativa para extração dos constituintes voláteis, a DMAA não foi econtrada nos óleos essenciais e nas folhas das espécies de Pelargonium, corroborando com outros estudos realizados, e indicando que a sua origem não é natural nestas espécies. A formulação final contendo a nanoemulsão com o óleo essencial apresentou atividade antifúngica superior a do óleo essencial livre. As análises das amostras apreendidas mostraram que mesmo após a sua proibição pelas agências regulatórias, os suplementos contendo DMAA e outros estimulantes ainda são comercializados, representando um grande risco para a saúde dos seus usuários. / 1,3-dimethylamylamine (DMAA) is a stimulant that started to be added in dietary supplements and weight loss compounds since 2006 and is widely consumed by athletes and the USA army. However, after reports of toxicity DMAA has been banned by regulatory agencies in Brazil and United States. However, even after its prohibition, DMAA still can be found in dietary supplements. Its origin was related to the essential oils of Pelargonium graveolens, and, however, many authors questioned the results and its natural origin. In addition, the essential oils of species of Pelargonium, had their antimicrobial activity reported against bacteria and fungi. Considering the aspects mentioned, this work aimed to determine the presence of DMAA in the essential oils by GC-MS, DART-MS/MS and LC-MS/MS; as well as in the leaves of the same species using the headspace extraction, previously optimized, followed by analysis through GC-MS. It has also been proposed to investigate the antifungal activity of essential oils of P. graveolens from different origins and develop a formulation containing an oil nanoemulsion for the treatment of vaginal candidiasis. Finally, it aimed to develop a screening method to evaluate the presence of DMAA and other stimulants in seized dietary supplements by DART-MS/MS. The results showed that DMAA is not present in the Rio Grande do Sul’s essential oils of Pelargonium spp. obtained by hydrodistillation. After optimization through experimental design, the headspace technique proved to be effective in extracting volatile constituents present in the leaves and, however, DMAA was not detected, as well as in commercial essential oils of P. graveolens from Brazil, China, Egypt, South Africa, Albania and Reunion Islands. The essential oils presented antifungal activity against five Candida species. Furthermore, this antifungal effect presented better results with the nanoformulation containing essential oil. DART-MS/MS screening was effective in detection of DMAA, ephedrine, synephrine, caffeine, sibutramine and methylphenidate in seized dietary supplements, showing positive results for all stimulants. Based on the results obtained and proposed objectives, it was verified that even after using three different analytical techniques and a new alternative for volatile constituents extraction, DMAA was not found in essential oils and leaves of Pelargonium spp., corroborating with other studies carried out, and indicating that its origin is not natural in these species. The final formulation containing the nanoemulsion with the essential oil had antifungal activity superior compared to 14 dispersed essential oil. The analysis of seized samples showed that even after its prohibition by regulatory agencies, supplements containing DMAA and other stimulants are still commercialized, representing a major health risk for their users.
122

Anti-aging activity of selected neutraceuticals in Drosophilia melanogaster. / CUHK electronic theses & dissertations collection

January 2011 (has links)
Peng, Cheng. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 142-163). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
123

Informovanost studentů vybraných škol v oblasti vybraných druhů nutraceutik / Selected schools' students' awareness of selected types of nutraceuticals

Homolková, Zuzana January 2018 (has links)
The main topic of this work is food supplements, their legislation and other theory connected with them, the main focus is on plant nutraceuticals, of which are chosen food supplements marketed to support immunity system - echinacea, sea buckthorn and oyster mushroom, food supplements to support psyche - St. John's wort, ginkgo and valerian and dietary supplements to support body fitness - tribulus, garcinia and psyllium. Subsequently, the topic focuses on the marketing of nutraceuticals, its modern ways and the possibilities of increasing the students' awareness in this field through the principles of media education. In the practical part, 112 students aged 15-19 are presented with a lecture presenting the topic and inviting students to raise their interest in the subject. The feedback of the lecture is provided by a questionnaire whose questions correspond to the hypotheses set by the author. KEYWORDS nutraceuticals, media education, marketing, Echinacea, Garcinia, Pleurotus, Hippophae, Gingko, Plantago, Hypericum, Valeriana, Tribulus
124

Addressing Potential Interactions Between Antineoplastics and Dietary Supplements

Bossaer, John B. 01 June 2015 (has links)
Excerpt: Interactions between chemotherapy and dietary or herbal supplements can compromise patient care.
125

Potential Toxicity of Caffeine when Used as a Dietary Supplement for Weight Loss

Pendleton, Morgan, Brown, Stacy D., Thomas, Christan M., Odle, Brian 08 February 2013 (has links)
Background: Caffeine is added to dietary supplements to increase energy and suppress appetite. Many people take dietary supplements for weight loss. Patients may be unaware that supplements can contain caffeine, even if caffeine is not listed as an ingredient. Commonly used herbal dietary supplement ingredients, such as guarana, are natural sources of caffeine. Objective: To describe a case of possible caffeine-induced seizure in a patient taking an over-the-counter weight loss supplement. Case Report: A previously healthy 38-year-old female experienced blurring of vision and a new onset grand mal seizure. The patient had a two-month history of taking the dietary supplement, Zantrex - 3™. Zantrex - 3™ is advertised as a weight loss supplement which may provide rapid weight loss and extreme energy in one “power packed pill.” Conclusions/Summary: After discontinuation of Zantrex - 3™, the patient experienced no further seizure activity. Outpatient follow up at 2 and 6 weeks was noncontributory with follow up MRI and EEG both within normal limits.
126

Effect of dietary ascorbic acid supplementation level on productivity, carcass characteristics and mortality of Venda chickens

Malebana, I. M. M. January 2009 (has links)
Thesis (M.Sc.) --University of Limpopo, 2009 / Two experiments were conducted to determine the effect of dietary ascorbic acid supplementation levels on productivity, carcass characteristics and mortality of Venda chickens. The first experiment determined the effect of dietary ascorbic acid supplementation levels on productivity and mortality rate of 175 unsexed Venda chickens between 1 and 6 weeks old. The second experiment determined the effect of dietary ascorbic acid supplementation levels on productivity, carcass characteristics and mortality rate of 140 female Venda chickens between 8 and 13 weeks old. A Completely Randomized Design was used in both experiments. The treatments ranged from 0 to 2000 mg of ascorbic acid per kg DM feed. A quadratic equation was used to determine levels of ascorbic acid supplementation for optimum feed intake, feed conversion ratio, growth rate, live weight and breast meat yield. Feed conversion ratio, growth rate and live weight were optimized at different levels of 1050, 1301 and 1500 mg of ascorbic acid per kg DM feed, respectively, during the starter phase. Similarly, feed conversion ratio, growth rate, live weight and breast meat yield were optimized at different levels of 1000, 1250, 1482 and 769 mg of ascorbic acid per kg DM feed, respectively, during the grower phase. Dietary feed intake in both phases was not optimized within the range of values of ascorbic acid supplementation used in this experiment. The results indicate that at each growth phase, different levels of ascorbic acid supplementation optimized feed conversion ratio, growth rate and live weight of Venda chickens. However, level of ascorbic acid supplementation for optimum breast meat yield was lower than those for feed conversion ratio, growth rate and live weight. These findings have implications on ration formulation for Venda chickens.
127

Influence of protein supplementation frequency on cows consuming low-quality forage : performance, grazing behavior, and variation in supplement intake

Schauer, Christopher Scott 28 July 2003 (has links)
Graduation date: 2004
128

Effect of infant feeding mode and maternal nutritional supplementation on the nutrition and health of HIV positive mothers and their infants.

Kindra, Gurpreet. January 2012 (has links)
Background: Breastfeeding is known to have benefits both for maternal and child health. Some questions around the benefits and risks of breastfeeding in the presence of HIV infection still remain unclear. Aims: To study the effects of infant feeding mode by HIV-positive mothers, on maternal and child health. In addition, to assess the effect of nutritional supplementation to HIV-positive lactating mothers on nutritional and health status of mothers and their infants and on the quality of breastmilk. Methods: The study had 2 components; a prospective study to examine the impact of infant feeding mode on nutritional and health indices in mothers and their infants and within it a nested randomized controlled clinical trial to study the impact of a daily 50 g soya/peanut based supplement during breastfeeding on the above parameters. The measurements included anthropometry; body composition indicators (using both deuterium dilution and BIA); haematology and biochemical markers; as well as incidence rates of opportunistic infections and clinical disease progression. Breastmilk was analysed for both macro and micronutrients. Cervical screening was offered to all the women. Results: AFASS criteria were fulfilled by 38.7% of the formula feeding mothers. No significant differences between the formula feeding and breastfeeding groups in terms of haematological, immunological and body composition changes were seen. Breastfeeding mothers had significantly lower events with high depression scores (p=0.043). Longer duration of breastfeeding was observed to be significantly associated with a mean increase in CD4 count (74 cells/μL) and better health outcomes. The supplement made no significant impact on any maternal or child outcomes except for a limited effect on mothers with low BMI, where it was significantly associated with preventing loss of lean body mass (p=0.026). Breastfeeding infants had a significantly lower risk of diarrhoea and hospitalisation at 3 months (p=0.006 and 0.014 respectively). Both breastfeeding and longer duration of breastfeeding was significantly associated with better development scores and growth parameters. Supplementation made no impact on breastmilk composition. Of the 86 mothers who agreed for cervical screening, 27.6% had human papilloma virus infection. Conclusions: Breastfeeding is not harmful to the mother despite the presence of HIV infection. On the contrary we observed both breastfeeding and longer breastfeeding duration to be associated with better maternal and child outcomes. Mothers are still choosing formula feeding inappropriately presumably because of the availability of free formula and/or sub-optimal counseling. The new (2010) local PMTCT guidelines based on WHO recommendations should reverse this. Food insecurity was prevalent amongst 32% of our study population, highlighting the need to include sustainable and empowering solutions to encounter this problem. Less sustainable solutions such as nutritional supplementation should be targeted to the malnourished and in emergency situations. / Thesis (Ph.D.)-University of KwaZulu-Natal, Durban, 2012.
129

The effects of ribose supplementation on swimming performance in collegiate male swimmers

Mauritzon, Petra January 2000 (has links)
The purpose of this study was to investigate the effects of ribose supplementation on swimming performance in collegiate male swimmers. Twenty trained collegiate male swimmers (mean ± SE; age: 19.7 ± 0.4 years; height: 182.6 ± 1.2 cm; weight: 75.9 ± 0.6kg) completed three randomly assigned trials; two prior to the supplementation period and one immediately after supplementation. The period between the first and the second trial was used as a control period and all subjects (n=20) participated. During the supplementation period the ribose group (n=10) received 20 g of ribose per day, while the placebo group (n=10) received 20 g of dextrose. The first day involved body composition, swim bench, and swim power measurements. The second day a test set consisting of 15x45.8 m freestyle swimming was performed. A blood sample was obtained from the antecubical vein prior to the swim and 1 minute after the completion of the last repeat. Swimming performance during the test set showed significant improvements for either group from T1 to T3. (mean ± SE 27.44 ± 0.32 and 27.55 ± 0.26 for the ribose and placebo groups respectively at T1). The times at the end of the supplementation period were 27.33 ± 0.28 and 27.36 ± 0.22 seconds. No significantdifferences were reported in swim power or swim bench. Lactate, uric acid, ammonia, and hypoxanthine did not significantly change for either group between the trials. The results from the study suggest that swimming performance does not appear to be enhanced with the supplementation of ribose during exhaustive exercise in collegiate male swimmers. / School of Physical Education
130

Effects of carbohydrate supplementation on variable-intensity exercise responses in boys and men

Guth, Lisa M. January 2009 (has links)
This study examined the physiological and perceptual effects of carbohydrate (CHO) on variable-intensity exercise (VIE) in boys and men. It was hypothesized that CHO would increase RER in boys and men and that this increase would be greater in boys. Additionally, it was hypothesized that RPE would be attenuated by CHO. Five boys (10-12 years) and seven men (18-30 years) consumed CHO or a placebo (PL) beverage before and throughout VIE. VIE included three 12-min sets of cycling; intensity varied every 20-30 seconds between 25, 50, 75, and 125% VO2max. Boys’ post-exercise glucose was higher in the CHO trial than the PL trial and RER was lower in boys than men, but was not affected by trial. RPE increased over time but was not different between groups or trials. Though VIE responses varied between boys and men, CHO ingestion before and during VIE did not provide physiological or perceptual benefits. / School of Physical Education, Sport, and Exercise Science

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