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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.
171

An assessment of medicinal hemp plant extracts as natural antibiotic and immune modulation phytotherapies

Case, Olivia Hildegard January 2005 (has links)
This study aimed to evaluate the antimicrobial efficacy of medicinal hemp plant extracts to determine the antibacterial effects of indigenous Sansevieria species and exotic Cannabis sativa phytotherapy varieties. This study also assessed whether aqueous o
172

Phytochemical studies of Helichrysum patulum.

Swartz, Vuyiswa Gladys January 2006 (has links)
<p>Since Helichrysum is known by the indigenous people of Africa for therapeutic properties, such as against colds, flu and wounds, the aim of this study was to focus on the patulum species found predominantly in the Western Cape region of South Africa and by means of isolation and identification of the plant constituents, be able to relate the therapeutic activity on the basis of literature precedents, to the compounds extracted.</p>
173

The formulation, manufacture and evaluation of capsules containing freeze-dried aqueous extracts of Leonotis Leonorus or Mentha Longifolia.

Ma, Haiqiu January 2006 (has links)
<p>Leonotis leonorus and Mentha longifolia are two herbs commonly used in South Africa, mostly in oral liquid dosage forms. Several disadvantages are associated with these traditional dosage forms which can perhaps be remedied by using an appropriate oral solid dosage form, provided the actual plant material in the latter still resemble, as closely as possible, the traditionally used material and provide products of suitable pharmaceutical quality. The objectives of this study were to prepare and evaluate the pharmaceutical suitability of the freeze-dried aqueous extracts of Leonotis Leonorus and Mentha Longifolia as plant raw material for the capsule dosage of these two therapies and to formulate and manufacture capsules of Leonotis Leonorus and Mentha Longifolia aqueous extract that would contain amounts of the plant materials equivalent to that found in their traditional liquid dosage forms, and have immediate release characteristics and suitability stability.</p>
174

The correlation between color and oxidation status in high oleic deep-frying oils: impact of antioxidants

XU, HUI 23 August 2016 (has links)
Frying oil is a heat and mass transfer medium, which affects the quality of food. The reaction mechanisms in deep-frying oils are mainly thermal oxidation, hydrolysis, and polymerization, which result in lipid deterioration. Addition of synthetic or natural antioxidants can effectively slow down lipid deterioration during deep-frying. Total polar components, polymerized triglycerides, p-anisidine value, acid value and iodine value are reliable indicators for assessing oil degradation during frying. Color darkening of deep-frying oils is one of apparent changes during deep-frying and is closely associated with the levels of decomposition compounds in the frying oils. However, the evidence of the relationship between color and deep-frying oil quality indicators are scanty. The main objective of this thesis is to develop a model for rapid assessment of oil quality during 30-hour deep-frying processes using oil color and quality as indicators. Significant color changes (p < 0.05) were observed in soybean oil as compared to canola and sunflower oil during 30-hour deep-frying trials. Canolol-enriched frying oils showed the highest color values before deep-frying, but the final results showed the least color changes (p < 0.05) during the 30-hour deep-frying trials. The highest percentage of total polar components (15.55 %), polymeric triglycerides (9.3 %), and p-Anisidine value (62.34) were found in TBHQ-enriched deep-frying oil samples in soybean oil. The highest acid value (3.06 mg KOH/100g) was found in canolol-enriched frying oil samples in canola oil. Rosemary and canolol-enriched deep-frying oil samples showed significant effect (p < 0.05) on color changes while reducing formation of total polar components, polymeric triglycerides, and aldehydes during the 30-hour deep-frying study. Significant correlations (p < 0.05) were found between color and oil quality indicators in all of the deep-frying oil samples; significant regression (p < 0.05) models are expressing the level of oil deterioration from color (light-dark, red-green, yellow-blue) in deep-frying oils. Overall, this study established several models using color as an indicator aiming to rapidly assess deep-frying oil quality. / October 2016
175

The Feasibility And Validity Of Novel Dietary Assessment Methods In A Pre-School Setting

Eriksen, Harley 01 January 2016 (has links)
To properly evaluate initiatives targeting children's fruit and vegetable (FV) consumption, we need feasible and valid dietary assessment methods that are time, cost, and resource effective. The objectives of this study were to test the feasibility and validity of two methods, digital imaging (DI) and aggregate plate waste (APW), for assessing children's FV consumption. UVM dietary assessment team graduate students prepared and distributed FV snacks in two pre-school classrooms over 30 consecutive school days. Feasibility of APW was tested by recording the frequency and weight of waste sorting errors by pre-school children and performing paired t-tests comparing uncorrected and corrected FV waste. Feasibility was tested for DI by determining the total number of individual FV snacks from which FV consumption could be estimated using the digital images. Validity was tested for DI using paired t-tests to compare FV consumption as assessed by DI against actual consumption as assessed by weighed plate waste (WPW). A total of 159 cluster APW weights were recorded during the 20 days of APW collection, with an overall mean difference of 0.57 grams (p=0.440) between uncorrected and corrected FV waste. Researchers were able to capture 100-percent usable digital images, effectively displaying 214 individual FV snack servings over the 10-day DI study period. Percent agreement between the two digital image coders was 99.1-percent. DI estimations for individual FV item and cumulative consumption were strongly correlated with WPW (all above r=0.97). Overall FV consumption as estimated by DI differed from WPW by less than one gram, and DI estimations for individual FV items differed from WPW by no more than two grams. Paired t-tests revealed no significant difference between DI estimations of clementine (p=0.954) and peapod (p=0.806) consumption and WPW measurements. However, paired t-tests indicated statistically significant differences between DI and WPW measurements for overall (p=0.001), grape (p=0.031), carrot (p=0.008), and pepper (p=0.027) consumption. Both methods were feasible for assessing mean FV consumption. DI estimations for individual FV items and cumulative consumption were strongly correlated with WPW, suggesting that despite statistical significance between DI and WPW measurements in some cases, the DI method is still precise for mean FV consumption evaluation. APW may be especially advantageous for rapid and efficient evaluation of behavior change in response to interventions targeting children's FV consumption. Due to ease of administration and instantaneous results, the APW method reduces the need for trained research staff to be present, drastically increasing accessibility to group-level dietary assessment.
176

Use and Perspectives of a Social Marketing Campaign to Improve Fruit and Vegetable Intake

Palmberg, Allison 01 January 2015 (has links)
The current study evaluated the development and acceptability of a social marketing campaign to improve emerging adults’ fruit and vegetable (FV) intake. A social marketing campaign was developed through focus groups with 24 college students. Materials were implemented in two dining locations at Virginia Commonwealth University. Sales of carrots, apples, and chips were collected in three phases: baseline, implementation of the campaign, and washout. In addition, surveys were collected from 303 diners across all phases and locations. Results indicated an increase in carrot sales, decrease in sales of chips sold with a meal, and mixed findings regarding sales of apples and chips sold alone. Intercept surveys indicated the marketing materials were perceived positively, and clearly understood. Statistical analysis of self-report measures revealed that perceptions of one’s health status and autonomy were associated with fruit and vegetable (FV) intake and overall nutrition knowledge. The implementation of a social marketing campaign to encourage FV intake appeared to influence sales of both healthy and non-healthy food items. It is vital for future campaigns and policies to highlight autonomy for health behavior decision-making.
177

Caracterização e modificação de poliuretano derivado de óleo vegetal para confecção de órteses / Characterization and modification of vegetable oil based polyurethane to orthosis fabrication

Souza, Mônica Cristina Assaiante de 12 September 2014 (has links)
As patologias que acometem os membros superiores são bastante incapacitantes para os seres humanos, pois elas são sua principal ferramenta de interação com o mundo tanto pelo papel nas tarefas cotidianas quanto pelo simbolismo que carregam. Na Terapia Ocupacional o objetivo é promover uma melhor qualidade de vida, maior autonomia e participação no cotidiano e, dentre os recursos e abordagens possíveis no processo de reabilitação, as órteses têm grande destaque, pois seu uso correto pode \"aumentar a função, prevenir ou corrigir deformidade, proteger estruturas em processo de cicatrização, restringir o movimento e permitir o crescimento ou remodelação tecidual\" (FESS, 2002, p.98). As órteses mais utilizadas na prática clínica são confeccionadas em material termomoldável de baixa temperatura. Não há opções nacionais deste material, implicando na necessidade de importação que pode gerar dificuldades no acesso a este tipo de material. Leite (2007) desenvolveu um poliuretano derivado do óleo vegetal (mamona) que se mostrou apto para a confecção de órteses após ensaios mecânicos, térmicos e clínicos, mas que necessita de melhorias, principalmente em relação aos aspectos de maleabilidade (moldabilidade) e memória do material. O presente trabalho tem como objetivos caracterizar o material desenvolvido e alguns existentes no mercado e modificar o material desenvolvido por Leite (2007). Para tanto, foram introduzidas modificações - acréscimo de cargas e mudanças na proporção poliol e pré-polímero - e realizados ensaios mecânicos e térmicos de Memória, Dureza, Moldabilidade, Análise Dinâmico-Mecânica, Tração, Temperatura no Contato com a Pele Humana e a velocidade de Resfriamento do material. Os resultados indicam que o acréscimo de Sílica Pirogênica e o aumento da proporção de poliol em relação ao pré-polímero melhoraram a moldabilidade do material e tornaram a memória adequada aos propósitos. Conclui-se que o novo material, o compósito CPU POS, é mais rígido que os importados, suportando maior carga, é seguro para o paciente do ponto de vista de temperatura e possui uma grande validade. A moldabilidade é rápida e necessita que o terapeuta posicione o material, pois ele não se acomoda com a ação da gravidade. A dureza foi diminuída, embora ainda seja maior que a dos materiais de comparação. Assim, o presente estudo contribuiu para um maior conhecimento dos termomoldáveis existentes no mercado utilizados para confecção de órteses e aponta o poliuretano derivado de óleo vegetal, modificado com cargas, como um material adequado para este propósito. / Pathologies that affect the upper limbs are very incapacitating to humans, because they are your primary tool for interaction with the world, both thé role of everyday tasks as the symbolism they carry. In Occupational Therapy the objective is promote a better quality of life, more autonomy and participation in daily life and, among the resources and possible approaches in the rehabilitation process, the orthosis have great prominence, because their correct use can \"enhance function, prevent or correct deformities, protect structures in the healing process, restrict movement and support the growth or tissue remodeling\" (FESS, 2002, p.98). The most used orthosis in clinical practice are fabricated with low temperature thermoplastic. There are no national options of this material, resulting in import which can create difficulties in accessing this type of material. Leite (2007) developed a vegetable (castor) oil based polyurethane that proved suitable for orthosis, after mechanical, thermal and clinical testing, but needs improvements especially aspects of malleability (moldability) and memory of the material. The current work aims at characterizing the material developed and some of the existing materials and modify the material developed by Leite (2007). Therefore, changes have been introduced - increase of fillers and changes in the proportion polyol to prepolymer - and performed mechanical and thermal tests of Memory, Hardness, Moldability, Dynamic Mechanical Analysis, Traction, Temperature in contact with human skin and the speed Cooling the material. The results indicate that the addition of Pyrogenic Silica and increased proportion of polyol in relation to the prepolymer improved moldability ofthe material and made appropriate memory to the purpose. We conclude that the new material, composite CPU POS, is more rigid than the imported, supporting higher load, it is safe for the patient in terms of temperature and has a great validity. The moldability is fast and requires the therapist to position the material, because it does not settle by gravity. The hardness was decreased, although it is still higher than the comparison material. Thus, the present study contributed to a better understanding of existing market thermoformables used for orthosis and points the polyurethane derived from vegetable oil, modified with fillers, as a suitable material for this purpose.
178

Desenvolvimento de novas combinações monômero - catalisador para a produção de polímeros via ROMP / Development of new catalyst-monomer pairs for bio-renewable thermoset production by ROMP

Castro, Marcela Portes de 19 July 2016 (has links)
Polímeros com diferentes características foram sintetizados a partir da polimerização por abertura de anel (Ring Opening Metahesis Polymerization-ROMP) de três diferentes monômeros de norborneno (NBE) derivados com triglicerídeos ou monoglicerídeos oriundos de óleos de mamona e de soja: Norbornenyl-functionalized castor oil (NCO), Norbornenyl-functionalized castor oil alcohol (NCA) e o novo Norbornenyl-functionalized epoxized soybean oil (NESBO). Utilizou-se como precursores catalíticos complexos do tipo [RuCl2(PPh3)2(amina)], amina = peridroazepina e piperidina, e catalisadores de Grubbs (1a e 2a geração). Foram investigados os efeitos da estrutura do monômero e do catalisador no processo de polimerização, bem como as propriedades térmicas e mecânicas dos polímeros resultantes. Através da ressonância magnética nuclear de hidrogênio (NMR-1H) foi determinado o número de sítios ativos (unidades de norborneno) por cadeia de ácido graxo em cada monômero: 1,8 em NCO, 2,6 em NCA e 4.5 em NESBO. O número de unidades monoméricas, assim como a viscosidade de cada monômero, desempenha um papel importante no controle da iniciação e propagação do processo de polimerização e nas propriedades finais dos polímeros obtidos. Os complexos do tipo Ru-amina, produziram materiais poliméricos similares aos obtidos com o catalisador de 1° Grubbs. Foram realizados estudos para otimizar as condições experimentais nas reações de ROMP, através da análise das estabilidades térmicas dos polímeros obtidos constatou-se a influência das variáveis tipo de catalisador, concentração de catalisador, tempo de reação, número de NBE por estrutura do monômero e a influência da adição de ácido na atividade catalítica dos complexos. Os valores de transição vítreas foram determinados através de DSC, o monômero de partida mostrou uma influência mais significativa sobre o valor de Tg dos polímeros obtidos do que o tipo de catalisador utilizado. Os estudos mecânicos dos materiais resultantes indicaram que foram obtidos desde materiais borrachosos a rígidos alterando a natureza do monômero e o tipo de catalisador utilizado e não foi possível estabelecer uma correlação entre as densidades de reticulação e a quantidade de anéis NBE da estrutura, nas condições analisadas. A cinética do processo de cura foi acompanhada através da ROMP induzida por temperatura, sob diferentes condições de frequência angular, temperatura e tempo. / Polymers with different characteristics were synthesized from the ring opening polymerization (ROMP) of three different monomers of norbornene (NBE) derived with triglycerides or monoglycerides from castor and soybean oils: Norbornene-functionalized castor oil (NCO), Norbornene-functionalized alcohol castor oil (NCA) and the new Norbornene-functionalized epoxidized soybean oil (NESBO). It was used, as catalyst precursors, complexes of the type [RuCl2(PPh3)2(amine)], amine = perhydroazepine and piperidine and the catalyst Grubbs (1st and 2nd generation). The effects of the structure of the monomer and catalyst in the polymerization process, as well as the thermal and mechanical properties of the resulting polymers, were investigated. Through the nuclear magnetic resonance of proton (1H-NMR), it was determined the number of active sites (norbornene units) per chain of fatty acid in each monomer: 1.8 to NCO, 2.6 to NCA and 4.5 to NESBO. The number of monomeric units (active sites for ROMP), as well as the viscosity of each monomer plays an important role in controlling the initiation and propagation of polymerization and the final properties of the polymers obtained. The Ru-amine complex type, produced polymeric materials similar to those obtained with Grubbs catalyst 1st. Studies were performed to optimize the experimental conditions in ROMP reactions, through analysis of the thermal stabilities of the obtained polymers was found to influence the variables: type of catalyst, catalyst concentration, reaction time, number of NBE in structure of the monomer and influence of acid addition on the catalytic activity of the complex. The glass transition values were determined by DSC, the starting monomer showed a more significant influence over the Tg value of all the obtained polymers compared to the all used catalysts. The mechanical studies of the resulting materials indicated that rubbery and rigid materials were obtained, by changing the nature of the monomer and type of catalyst, although it was not possible to determine a correlation between the crosslinking densities and the quantity of NBE rings of the structure for the analyzed conditions. The kinetic for the cure process was followed through the induced ROMP by temperature under different conditions of angular frequencies, temperature, and time.
179

Avaliação do uso de óleos de origem vegetal para formulação de adjuvantes vacinais / Assessment of the use of vegetable oils for formulation of vaccine adjuvant.

Carvalho, Marnen Almeida 27 July 2012 (has links)
Os óleos vegetais são matérias primas de fontes renováveis. São metabolizáveis, biodegradáveis, de fácil disponibilidade e baixo custo. A necessidade de adjuvantes vacinais seguros e que possam modular a resposta imunológica Th1/Th2, favorece a busca por novas substâncias que assim se comportem. Este trabalho tem o objetivo de avaliar e identificar óleo vegetal capaz de mimetizar ação adjuvante dos óleos minerais comercialmente usados e modular a resposta imune. Foram realizados testes de toxicidade aguda in vivo, testes de formação de emulsões, de estabilidade, de qualidade e, por fim, de imunogenicidade com formulações com o vírus rábico. Algumas formulações derivadas dos óleos de girassol, canola e buriti se mostraram não tóxicas, estáveis e de boa qualidade. Os grupos de camundongos inoculados com estas formulações obtiveram respostas imunológicas que apoiam sua capacidade adjuvante, não diferenciando significativamente (p<0,05) dos resultados do óleo mineral comercial. Concluiu-se que é possível elaborar emulsões estáveis não tóxicas a partir de óleos vegetais para sua utilização como veículos e adjuvantes vacinais. Formulações vacinais em forma de emulsões de óleos vegetais, compostas na sua maior parte pelos óleos de girassol e de canola possuem potência e atividade adjuvante semelhantes e tão eficientes quanto aos do óleo mineral. Os óleos vegetais devem estar em seu estado bruto ou semirrefinado, sem a adição de antioxidantes e conservantes. Por último, parece haver uma tendência de equilíbrio de resposta Th1/Th2 para as formulações com óleos vegetais. / Vegetable oils are renewable raw materials. These substances are metabolizable, biodegradable, of easy availability and low cost. The need for safe vaccine adjuvants that can modulate the Th1/Th2 immune response drives the search for new substances with similar behavior. This study aims to evaluate and identify a vegetable oil able to mimic the adjuvant action of the mineral oils used commercially, and modulate the immune response. There were performed tests of in vivo acute toxicity, emulsion formation, stability, quality and immunogenicity with formulations with rabies virus. Some formulations derived from the sunflower, canola and buriti oils proved to be non-toxic, stable and of good quality. Groups of mice inoculated with these formulations had immune responses supporting their adjuvant capacity, not differing significantly (p <0.05) from the results of the commercial mineral oil. It was concluded that it is possible to prepare stable non-toxic emulsions from vegetable oils to be used as vaccine adjuvants and vehicles. Vaccine formulations as emulsions from vegetable oil, composed mostly by the oils of sunflower and canola had adjuvant activity and potency similar to and as effective as the mineral oil. The vegetable oils should be in its raw state or semi refined, without the addition of antioxidants and preservatives. Finally, there seems to be a tendency to balance Th1/Th2 response by formulations with vegetable oils.
180

The response of soil microbial communities to vegetable cropping systems analyzed for RNA- and DNA-based sampling

Gomez-Montano, Lorena January 1900 (has links)
Doctor of Philosophy / Department of Plant Pathology / Ari Jumpponen / Megan Kennelly / Soil microbial communities play fundamental and complex roles in the productivity of agriculture. However, we still have a limited understanding of the response of microbial communities to different farming systems, such as organic and conventional fertility management regimens. We applied high-throughput sequencing to develop a better understanding of how soil microbial communities (bacteria and fungi) in vegetable production respond to organic or conventional soil fertility management. Specifically, my three studies examined the following questions: 1. How do soil microbial communities from cDNA and DNA samples compare in organic and conventional fertility treatments? 2. How do soil microbial communities in a tomato cropping season respond to long-term organic vs. conventional soil fertility treatments? 3. How do soil bacterial and fungal communities respond to high tunnels, plastic mulch and organic amendments across a tomato cropping season? The first two questions were addressed at the Kansas State University Horticulture and Extension Center in Olathe, KS, using organic and conventional field plots with three levels of fertilizer. We sampled the plots during the development of a tomato crop. The third question was addressed at a commercial farm in Lawrence, KS, during its transition to organic vegetable production, during a tomato crop. The Lawrence experiment included as treatments field plots versus high tunnels, and three organic nutrient amendments. We used 454-pyrosequencing of bacterial and fungal ribosomal markers to compare total resident (DNA) and active microbial communities (cDNA, which is DNA synthesized from a single stranded RNA template) for our first question. We used Illumina MiSeq metabarcoding of bacterial and fungal ribosomal markers for our second and third questions. In all three studies we evaluated bacterial and fungal community responses using Simpson´s diversity index, Simpson´s evenness and richness for each experiment. For the first question, when we compared DNA and cDNA, bacterial diversity was higher in cDNA samples from organic compared to conventional management. In addition, fungal diversity from cDNA samples was higher than from DNA samples. In contrast, in the second question, bacterial and fungal diversity indices did not differ in the tomato crop under organic and conventional management systems. For our third question, high tunnels did not affect bacterial or fungal diversity. Use of plastic mulch for a tomato crop in open field plots did not affect bacterial richness, but decreased fungal richness compared to open field plots without plastic mulch. High-throughput sequencing provides a new perspective on the structure and dynamics of these communities. Information from this approach will ultimately improve our ability to manage soil for sustainable productivity by promoting beneficial microorganisms and suppressing pathogenic ones.

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