A obstrução de cateter venoso central totalmente implantado (CV-TI) é uma das complicações relacionadas ao seu uso. A recuperação da permeabilidade do CVC-TI é a maneira mais adequada de lidar com esta complicação por se tratar de uma intervenção mais rápida e de menor custo quando comparado com o reposicionamento ou a troca do dispositivo. O ácido ascórbico (AA) vem sendo utilizado em alguns hospitais brasileiros e resultados satisfatórios têm sido obtidos. Estudos in vitro relataram que o AA atua no processo fibrinolítico e pode contribuir para a desobstrução de cateter venoso central de longa permanência. O presente estudo tem por finalidade determinar a dose de segurança do ácido ascórbico para o tratamento da obstrução de cateter venoso central totalmente implantado. Trata-se de ensaio clínico fase II, randomizado em três grupos de tratamento (50mg, 100mg e 200mg de ácido ascórbico), não controlado, conduzido em quatro hospitais brasileiros. Para isso, foram incluídos 21 sujeitos com idade média de 53 anos, a maioria com diagnóstico de câncer de mama. Seis sujeitos obtiveram sucesso com o tratamento proposto, apresentando a desobstrução do cateter. Dentre eles, quatro receberam a dose de 50 miligramas e apresentaram desobstrução completa ou parcial. Em relação ao tempo de desobstrução, três cateteres foram desobstruídos em menos de 60 minutos e três em 60 minutos; entre eles, dois que haviam recebido dose de 50 miligramas. Observou-se, também, que houve relação entre a presença de obstrução anterior e a falha no tratamento com AA. Além disso, aqueles que não tiveram o cateter desobstruído apresentaram intervalo de tempo maior entre o diagnóstico da obstrução e o tratamento da mesma, onde foram identificados 355 dias contra 112 dias naqueles que tiveram o cateter desobstruído. A variável de segurança analisada demonstrou que o ácido ascórbico não induziu reações de hipersensibilidade nesses sujeitos. Conclui-se, portanto, que o tamanho de amostra obtido é insuficiente para afirmar que o ácido ascórbico não seja eficaz na desobstrução de cateter venoso central totalmente implantado. Os resultados encontrados neste estudo nos levam a sugerir, por ora, que a dose de 50mg pode ser testada em um ensaio clínico de fase III, com amostra maior, a fim de validar o uso do ácido ascórbico como um possível agente eficaz no tratamento da obstrução de cateter totalmente implantado. / The occlusion of totally implanted central venous catheter (TI-CVC) is one of the catheterrelated complications. The recovery of the permeability of the TI-CVC is the most appropriate way of dealing with this complication, once it is a faster and less costly intervention than the reposition or change of the device. Ascorbic acid (AA) has been used in some Brazilian hospitals and satisfactory results have been obtained. In vitro studies have reported that AA acts on the fibrinolytic process and can contribute to restore the patency of indwelling central venous catheters. This study aimed to determine the safe dosage of ascorbic acid for the treatment of occluded totally implanted central venous catheter. It is a phase II clinical trial, randomized into three treatment groups (50mg, 100mg and 200mg of ascorbic acid), not controlled, carried out in four Brazilian hospitals. In total, 21 subjects with average age of 53 years were included, most of them diagnosed with breast cancer. Six subjects had success in the proposed treatment, presenting the patency of the catheter. Among them, four were given a dose of 50 milligrams and presented complete or partial patency. Concerning the time of patency, three catheters were cleared in less than 60 minutes and three in 60 minutes, including two that had received a dose of 50 milligrams. Association between the presence of previous obstruction and failure in treatment with AA was also observed. Moreover, those who did not have the catheter cleared presented higher time interval between diagnosis of obstruction and treatment of it, being the intervals 355 days opposed to 112 days for those who had the catheter cleared. The safety variable analyzed showed that ascorbic acid did not induce hypersensitivity reactions in these subjects. It is concluded that the sample size obtained is insufficient to state that ascorbic acid is not effective in clearing totally implanted central venous catheter. Results from this study suggest, for now, that the 50mg dose can be tested in a phase III clinical trial, with larger sample, as to validate the use of ascorbic acid as an agent in the treatment of occluded totally implanted catheter.

O exercício físico intenso altera o sistema antioxidante, aumentando a geração de radicais livres e/ou diminuindo a concentração de antioxidantes. Assim o objetivo deste estudo foi verificar os efeitos da oferta de vitamina C através de um suplemento alimentar e dieta rica em ácido ascórbico no estresse oxidativo induzido pelo exercício. A amostra foi composta por 13 nadadores de elite (6 homens e 7 mulheres), com idades entre 18 e 26 anos, IMC médio 21,8kg/m², que treinavam em média 19,4h semanais. Os atletas foram submetidos à carga de exercício aguda em 3 fases, controle (C), dieta rica em vitamina C (D) e suplemento de vitamina C (S), nas quais amostras de sangue foram colhidas antes, imediatamente após e 24 horas depois do exercício, para determinação bioquímica e do estresse oxidativo. O uso de suplementos alimentares foi feito pela maioria dos nadadores (92,3%), e os suplementos mais usados eram Maltodextrina, associação de proteína e carboidrato, enquanto o relato do consumo de antioxidantes não foi muito freqüente (25%). Em relação ao consumo de antioxidantes, os nadadores apresentavam consumo alimentar variável de vitamina C, sendo que muitos deles apenas adequaram o consumo devido à adição feita pelo estudo. O consumo de vitamina E foi inadequado para todos os atletas, já o consumo de selênio, retinol e zinco tiveram uma grande oscilação. Durante as fases o único antioxidante que apresentou flutuações foi o ácido ascórbico, que foi menor na fase C em relação às outras fases. Para a maioria dos indivíduos o consumo de carboidrato e fibras se mostrou insuficiente, e o de lipídeos e calorias adequados, enquanto o consumo de proteínas variou bastante. O uso de dieta rica em vitamina C favoreceu uma menor peroxidação lipídica em nadadores de alto rendimento, já que apresentou menores valores de FOX, e diminuição da peroxidação lipídica após exercício, pela diminuição dos valores de TBARS, enquanto tiveram aumento dos níveis de vitamina C no plasma logo após o exercício. Enquanto o uso de suplemento de vitamina C, que também conteve a peroxidação lipídica após exercício, aumentou o poder antioxidante nos mesmos nadadores, devido maiores níveis do antioxidante GSH. Os quais sem uso de nenhuma adição de vitamina C tiveram um maior dano hepático e tecidual, pois apresentaram maiores níveis de TGO, menores níveis de antioxidantes, devido aos baixos níveis de vitamina C e GSH, e um aumento do ácido úrico, um antioxidante que aumenta em situações onde há grande quantidade de radicais livres presentes. Ainda pode-se verificar que, antes do exercício, quanto mais ácido ascórbico na dieta mais vitamina C, menos TGO e menos ácido úrico no sangue; e ainda logo após o exercício e 24 horas depois quanto mais ácido ascórbico menos TGO e menos ácido úrico séricos. Sendo assim as mudanças observadas com a adição de vitamina C à dieta de nadadores de alto rendimento sugere um importante papel do ácido ascórbico plasmático e da suplementação alimentar na defesa contra o estresse oxidativo induzido pelo exercício / The strenuous exercise alters the antioxidant system by increasing the generation of free radicals and / or decreasing the concentration of antioxidants. Then the aim of this study was to investigate the effects of supply of vitamin C through a dietary supplement and diet rich in ascorbic acid in the exercise-induced oxidative stress. The sample was compound of 13 elite swimmers (6 men and 7 women) aged between 18 and 26 years, average BMI 21.8 kg / m², who trained on average 19.4 hours per week. The athletes were submitted to acute exercise load in three phases: control (C), diet rich in vitamin C (D) and supplement vitamin C (S), in which blood samples were collected before, immediately after and 24 hours after exercise to biochemical determination and oxidative stress. The use of dietary supplements is done by most of the swimmers (92.3%), and supplements most used were maltodextrin, association of protein and carbohydrate, while the report of consumption of antioxidants was not very frequent (25%). Regarding the consumption of antioxidants, the swimmers had dietary vitamin C variable, and many of them just adjusted consumption due to addition made by the study. The consumption of vitamin E was inadequate for all athletes, while the consumption of selenium, retinol and zinc had a great oscillation. During the phases the only antioxidant that showed fluctuations was ascorbic acid, which was lower in phases C when compared to other phases. For most individuals the consumption of carbohydrates and fibers were insufficient, and lipid and calories adequate, while protein intake varied widely. The use of diet rich in vitamin C favored a lower lipid peroxidation in swimmers high performance, then showed lower values of FOX, and decreased lipid peroxidation after exercise by the decrease in TBARS values, while they had increased levels of vitamin C plasma immediately after exercise. While the use of supplement vitamin C, which also contained the lipid peroxidation after exercise, increased the antioxidant power of the same swimmers, due higher levels of the antioxidant GSH. This without use addition of vitamin C had a greater damage liver and tissue, because they showed higher levels of TGO, lower levels of antioxidants, due lower levels of vitamin C and GSH, and increased uric acid, an antioxidant that increases in situations where there are lots amount the free radicals presents. Further can be seen that, before exercise, the more ascorbic acid in vitamin C diet, less TGO and less uric acid in blood, and even after exercise and 24 hours after the more ascorbic acid less serum TGO and uric acid. Thus the observed change with the addition of vitamin C to the diet of high-performance swimmers suggests an important role of ascorbic acid and dietary supplementation in protecting against exercise-induced oxidative stress.

"The stiffness of scaffolds used in surgical ventricular restoration may play an important role in the degree to which they facilitate regeneration of functional cardiac tissue. The stiffness of the scaffold influences the phenotype of cells which are present in it as well as their ability to deform the scaffold. The goal of this study was to evaluate in vitro methods to characterize and alter the stiffness of new scaffold materials. Membrane inflation testing, an in vitro mechanical testing method, was evaluated in this study because of its ease of use and the similar mode of loading which it shares with scaffolds implanted in vivo. The structural stiffness of two scaffold materials, urinary bladder matrix and Dacron, were determined in vivo and using membrane inflation testing. Despite higher tensions and lower area stretch ratios for scaffolds tested using membrane testing, similar changes in structural stiffness between the two materials were found for both methods (5.6 ± 3.3 fold in vivo, 5.0 ± 1.0 in vitro). This finding demonstrated that membrane inflation testing is a useful in vitro method for measuring changes in structural stiffness between scaffold materials with a level of sensitivity similar to that which is measured in vivo. Membrane inflation testing was used to assess the effectiveness of altering scaffold stiffness through exposure to various cell culture conditions. Incubation of a biological membrane in cell culture media resulted in a drastic decrease in the elastic modulus from its initial value (3.55 ± 0.52 MPa) after 2 weeks (1.79 ± 0.30 MPa), 4 weeks (1.04 ± 0.09 MPa), and 10 weeks (0.014 ± 0.01 MPa). When fibroblasts were cultured on the scaffolds for 10 weeks an increase in elastic modulus (0.134 ± 0.05 MPa) over scaffolds incubated in culture media for the same amount of time was observed. The increase in elastic modulus due to the presence of fibroblasts was accompanied by an increase in the percentage of collagen in the samples (54.1 ± 5.1 % without fibroblasts, 83.2 ± 5.1 % with fibroblasts). Contrary to expectation, addition of ascorbic acid to the media to increase production of collagen by the fibroblasts resulted in a decrease in elastic modulus (0.030 ± 0.01 MPa) compared to scaffolds cultured with fibroblasts in standard media and a decrease in the amount of enzymatically degraded collagen (40.8 ± 4.7 % without ascorbic acid, 21.1 ± 3.3 % with ascorbic acid). Regeneration of cardiac tissue after a myocardial infarction is a complicated process which is influenced by a myriad of different factors. Future studies investigating the exact role which substrate stiffness has on regeneration will be essential to the development of improved cardiac scaffolds. Characterization of the stiffness of these scaffolds by membrane inflation and manipulation through exposure to cell culture conditions are powerful approaches to facilitate future studies."

A enzima lipoxigenase através da farinha integral de soja é amplamente utilizada na panificação com objetivos de branqueamento e melhora da reologia. Com base nesse pressuposto, o objetivo inicial deste estudo foi de observar a ação oxidante dessa enzima na presença de dois outros oxidantes (ácido ascórbico e peróxido de benzoíla) nas propriedades reológicas e sensoriais de pães. Sete misturas com diferentes combinações dos três compostos foram elaboradas utilizando-se um delineamento experimental do tipo \"centroide-simplex\", sendo aplicadas à farinha de trigo para o preparo de pães. A enzima apresentou sinergia com o ácido ascórbico na elasticidade da massa, sugerindo uma inter-relação bioquímica entre os dois compostos no fortalecimento da matriz protéica do glúten. A mesma sinergia entre a lipoxigenase da soja e o acido ascórbico foi observada na redução da tonalidade amarela dos pães medida instrumentalmente. A partir desses resultados, buscou-se avaliar a ação da enzima frente a variações tanto na força da farinha como no tempo de fermentação, reproduzindo as condições reais de processamento. Desta vez, um planejamento experimental do tipo Box-Behnken com três fatores (atividade da enzima, força da farinha e tempo de fermentação) em três níveis de variação, foi aplicado no preparo das amostras. Os resultados mostraram que a lipoxigenase da soja (fração 1) é uma enzima oxidante de ação rápida e seu efeito no branqueamento dos carotenóides da farinha de trigo exibiu interação positiva tanto com a força da farinha como o tempo de fermentação. Respostas reológicas e sensoriais decorrentes da ação conjunta de diferentes oxidantes e condições de processamento em pães foram pela primeira vez descritas através de modelos polinomiais com capacidade preditiva. / Soy lipoxygenase enzyme through soy flour is widely used in breadmaking for bleaching and rheological improvement. Based on this fact, the initial objective of this study was to observe the enzymes\' action in the presence of two other oxidants (ascorbic acid and benzoyl peroxide) in the rheological and sensory properties of breads. Seven mixtures with different combinations of the three compounds were prepared using a \"centroid-simplex\" design and applied to wheat flour for breadmaking. The enzyme showed synergism with ascorbic acid in the dough elasticity suggesting a biochemical interrelation between the two compounds in strengthening the gluten protein matrix. The same synergy between soy lipoxygenase and ascorbic acid was observed with the yellow hue reduction of breads measured instrumentally. From these results, the enzyme action was evaluated with wheat strength and proofing time variations reproducing real processing conditions. This time, a Box-Behnken experimental design with three factors (enzyme activity, wheat strength and proofing time), and three variation levels were applied in the sample preparation. The results showed that soy lipoxygenase (type 1) is a fast-acting oxidizing enzyme and its bleaching effect on wheat flour carotenoid exhibited a positive interaction with wheat strength and proofing time. Rheological and sensory results attributed to the combined action of the different oxidants and breadmaking conditions were for the first time described through polynomial models with predictive capacity.

Resumo: A osteoartrose se caracteriza pela degeneração articular, perda de cartilagem e alterações no osso subcondral. Pouco se sabe sobre a patogênese e mudanças que ocorrem na osteoartrose como também em seu reparo. As técnicas terapêuticas disponíveis podem resultar em alívio dos sintomas, mas não na regeneração do tecido lesado. Um dos métodos usuais para pesquisa em osteoartrose com o preceito de mimetizar esta situação e também realizada neste trabalho, é o modelo experimental utilizando a inoculação intra-articular de zymosan (Saccharamyces cerevisiae), gerando artrite em grau progressivo. A eletroterapia potencializa a reparação de tecidos conjuntivos representando uma alternativa na reparação de lesões da cartilagem hialina. O acido ascórbico é um dos precurssores do colágeno que junto com outras estruturas complexas como a trama de glicosaminoglicanas e proteoglicanas constitui a cartilagem. A utilização dessa técnica para administração do acido ascórbico em tecido biológico é fator substancial do presente trabalho. Objetivo: O objetivo do presente estudo foi verificar a resposta imuno-bioquímica e avaliar microscopicamente a cartilagem articular de ratos artrose induzidos, frente ao tratamento com iontoforese na presença e ausência de acido L - ascórbico. Materiais e Métodos: Ratos wistar machos divididos em 6 grupos de 6 animais cada um, diferenciados em grupos: controle positivo C+, controle negativo C-,gavagem com solução fisiológica GSF, gavagem com ácido ascórbico GAA, iontoforese solução fisiológica IFSF iontoforese com ácido ascórbico IFAA.Resultados: Histológicos demonstraram em coloração Hematoxilina e Eosina que com o grupo IFAA obteve normalidade da variável celularidade (40.1 mm2), e manutenção da cartilagem não calcificada (75.5mm) (p<0.05), sugerindo espessuras normais. Quanto ao grupo não tratado C+ apresentou-se menor... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Osteoarthritis is characterized by joint degeneration, loss of cartilage and subchondral bone changes. Little is known about the pathogenesis and changes that occur in osteoarthritis as well as in its repair. Available therapeutic techniques can result in relief of symptoms but not in the regeneration of injured tissue. One of the usual methods for research used in this study is the experimental model which uses intra-articular inoculation of zymosan (Saccharamyces cerevisiae), causing arthritis in progressive degree. Electrotherapy enhances the healing of tissues representing an alternative in the repair of hyaline cartilage injuries. Ascorbic acid is one of the forerunners of collagen which along with other complex structures like the chains of glycosaminoglycans and proteoglycans form the cartilage. The use of this technique for administration of ascorbic acid in biological tissue is a substantial factor in this study. Objective: The objective of this study was to investigate the immune-biochemical reply and evaluate microscopically the histology of articular cartilage in rats arthritis induced, compared to treatment with iontophoresis in the presence and absence of L - ascorbic acid. Methods: Male wistar rats were divided into 6 groups of 6 animals each, in different groups: positive control C+, negative control C-, gavage with saline solution GSS, gavage with ascorbic acid GAA, saline iontophoresis IPSS, iontophoresis with ascorbic acid IPAA. Results: Histological it was demonstrated that in hematoxylin and eosin staining the group that received IPAA obtained normality of variable (40.1 mm2), and maintenance of non calcified cartilage (75.5mm) (p<0.05), suggesting normal thickness. Regarding the untreated group C+, it presented lower average in the number of chondrocytes (13.0mm2), and with regard to the thickness of cartilage it had a higher average of calcified cartilage with... (Complete abstract click electronic access below) / Orientador: Olga Maria Mascarenhas de Faria Oliveira / Coorientador: Maria Rita Pacheco / Banca: Iguatemy Lourenço Brunetti / Banca: Ana Maria Minarelli Gaspar / Banca: Ticiana Sidorenko de Oliveira Capote / Banca: Fábio Viaddanna Serrão / Doutor

Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2017-04-25T11:14:43Z No. of bitstreams: 1 2012 - Liane Caroline S Nascimento.pdf: 1534381 bytes, checksum: a4191d92ac386756692de94030e95ef7 (MD5) / Made available in DSpace on 2017-04-25T11:14:43Z (GMT). No. of bitstreams: 1 2012 - Liane Caroline S Nascimento.pdf: 1534381 bytes, checksum: a4191d92ac386756692de94030e95ef7 (MD5) Previous issue date: 2012-06-25 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / This paper describes the investigation of the centesimal composition, chemical and antioxidant activity of Morinda citrifolia L. (Rubiaceae), native of Southeast Asia, popularly known as noni, which has emerged in Brazil as a plant with great healing potential. The empirical knowledge of the population has meant that the fruit is constantly present in the diet of Maranh?o. Early in the second half of 2010 seedlings of the species were planted in two experimental areas of the Federal Institute of Maranh?o (IFMA), Campus of Z? Doca-MA, broken down by planting time. After three months of the planting in the first area the fruiting process was initiated, and it was possible to perform bromatologic analyzes. For the centesimal composition was found in pulp, seed and mixtures of both, respectively: the ash content (0,82%?0,01; 0,60%?0,01 e 0,79%?0,03), moisture (90%?0,01; 28,34%?0,01; 80,64%?0,05), proteins (4,2%?0,01; 7,47%?0,06; 4,70%?0,02), total lipids (0,34%?0,04; 0,79%?0,03; 0,63%?0,07), carbohydrates (2,68%?0,01; 25,83%?0,02; 13,24%?0,01) and calorific value (30,58kcal/100g?0,02; 140,31 kcal/100g?0,03; 77,43 kcal/100g?0,03). It was found in the pulp and seed values soluble dietary fiber (0,51?0,04; 0,93%?0,03) and insoluble (1,44?0,05; 36,04%?0,38). For the chemical characterization it was found in the pulp, seed and mixtures of both: ? Brix (8,17?0,05;-), the total acidity (0,54?0,02; 0,28?0,01; 0,62?0,02%) and pH (3,95?0,07; 4,5?0,04; 4,1?0,05), the relationship TA / SS pulp was 14.97?0,07. The content of ascorbic acid was calculated by the method Tilmans, pulp and seed fractions (117,33?0,01; 24,33?0,03), expressed in mg/100 g sample. The antioxidant capacity analyzes were performed in three different parts: the pulp, peel and seed using alcoholic extracts (11,63?0,07; 10,03?0,04; 11,19?0,01) and aqueous extract (7,20?0,07; 6,98?0,07; 7,60?0,01) through the sequestration of free radical DPPH, expressed in mM of Trolox / g sample. It was further evaluated the antioxidant capacity of different extracts of the three parts of the fruit and alcoholic extract (98.78% in pulp, 84.76% in peel and 94.96% in the seed) showed much higher antioxidant capacity than the aqueous extract ( 8.08% in the pulp, 5.22% in peel and 22.66% in the seed) and the prominence given to the pulp, followed by seed and peel, respectively. It was demonstrated that the noni fruit grown in the municipality of Z? Doca presented a rich source of nutrition important fact that justifies its inclusion in the diet. It should be noted that the pulp showed a high content of vitamin C and antioxidant activity, and seed a significant amount of insoluble fiber, suggesting that this product can be inserted in the consumer market for being a nutritious food with great herbal medicine potential / Este trabalho descreve a investiga??o da composi??o centesimal, qu?mica e atividade antioxidante de Morinda citrifolia L. (Rubiaceae), origin?rio do sudoeste da ?sia, popularmente conhecida como noni, que vem se configurando no territ?rio brasileiro como um vegetal com grande potencial fitoter?pico. O conhecimento popular tem feito com que o fruto esteja presente constantemente na dieta alimentar maranhense. No in?cio do segundo semestre de 2010 foram plantadas mudas da esp?cie em duas ?reas experimentais do Instituto Federal do Maranh?o (IFMA), Campus Z? Doca-MA, divididas por ?poca de plantio. Ap?s tr?s meses do plantio na primeira ?rea o processo de frutifica??o foi iniciado, sendo poss?vel realizar as an?lises bromatol?gicas. Para composi??o centesimal verificou-se na polpa, semente e mistura de ambos, respectivamente: o teor de cinzas (0,82%?0,01; 0,60%?0,01 e 0,79%?0,03); a umidade (90%?0,01; 28,34%?0,01; 80,64%?0,05); prote?nas (4,2%?0,01; 7,47%?0,06; 4,70%?0,02); lip?deos totais (0,34%?0,04; 0,79%?0,03; 0,63%?0,07); carboidratos (2,68%?0,01; 25,83%?0,02; 13,24%?0,01) e valor cal?rico (30,58 kcal/100g?0,02; 140,31 kcal/100g?0,03; 77,43 kcal/100g?0,03). Verificou-se na polpa e semente os valores de fibras alimentares sol?veis (0,51?0,04; 0,93%?0,03) e insol?veis (1,44?0,05; 36,04%?0,38). Para caracteriza??o qu?mica verificou-se na polpa, semente e mistura de ambos: o ?Brix (8,17?0,05;-), a acidez total (0,54?0,02; 0,28?0,01; 0,62?0,02%) e o pH (3,95?0,07; 4,5?0,04; 4,1?0,05), a rela??o ATT/SS na polpa foi de 14,97?0,07. O Teor de ?cido asc?rbico foi calculado pelo m?todo Tilmans, nas fra??es polpa e semente (117,33?0,01; 24,33?0,03), expressos em mg/100g amostra. As an?lises da capacidade antioxidante foram realizadas em tr?s partes diferentes: polpa, casca e semente utilizando extrato alco?lico (11,63?0,07; 10,03?0,04; 11,19?0,01) e extrato aquoso (7,20?0,07; 6,98?0,07; 7,60?0,01), atrav?s do sequestro do radical livre DPPH, expressos em ?M de Trolox/g amostra. Foi ainda avaliada a capacidade antioxidante dos diferentes extratos, das tr?s partes do fruto e o extrato alco?lico (98,78% na polpa; 84,76% na casca e 94,96% na semente) apresentou capacidade antioxidante bem maior que o extrato aquoso (8,08% na polpa, 5,22% na casca e 22,66% na semente) sendo o destaque dado ? polpa, seguido da semente e da casca, respectivamente. Demonstrou-se que os frutos do noni cultivados no munic?pio de Z? Doca apresentaram uma rica fonte nutricional importante fato que justifica sua inser??o na dieta alimentar. Cabe destacar que a polpa apresentou um elevado teor de vitamina C, e atividade antioxidante, e a semente um relevante teor de fibras insol?veis, sugerindo que esse produto pode ser inserido no mercado consumidor por ser um alimento nutritivo e com grande potencial fitoter?pico.

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.

Thesis (M.Sc. (Pharmaceutics))--North-West University, Potchefstroom Campus, 2007.

Lignins are produced by all vascular plants and they represent one of the most abundant groups of biopolymers in nature. Lignin chemistry research, which has been of great importance for the progress of pulping technologies, has been plagued by the difficulties of its isolation and characterization. The pioneering work of Karl Freudenberg in the 1950’s with synthetic models of lignin paved the way for a detailed structural characterization of many lignin substructures. His work with the so-called “synthetic lignins” or dehydrogenative polymers (DHP) also laid a foundation for understanding how different lignin substructures are formed, reinforcing the already existing theory of lignin polymerization. However, subsequent structural characterizations of DHPs and lignins have repeatedly put this theory to the test. In the past decade, even a new radically different hypothesis for lignin polymerization has emerged and is sustained by a few researchers in the field. In this work, DHPs were produced from phenolic monomers, mostly coniferyl alcohol, a common lignin monomer, in a variety of reaction conditions. This was done in order to establish how different chemical factors, potentially active in the plant cell wall during lignin polymerization, influence the polymer’s final properties. In the presence of nicotine amide adenine dinucleotide (NADH), a quinone methide model, which is an intermediate formed during lignin polymerization, was effectively reduced. An equivalent reduced structure was produced during DHP synthesis in the presence of NADH. These studies showed that reduction might take place during oxidative polymerization, possibly explaining how reduced lignin structures are formed in the plant cell wall. Another reductive agent, ascorbic acid, was also tested during synthesis of DHPs. It displayed a totally different effect than NADH, probably due to its anti-oxidant nature, by altering the final amounts of certain inter-unit substructures, in favour of β-O-4′ structures, which are so prominent in natural lignins. Furthermore, the new suggested model for lignin polymerization, stating that lignin itself possesses the ability for template replication, was tested by synthesizing DHPs in the presence of a simple β-β′ substructure model. The DHPs produced the same amounts of β-β′ substructures as a control synthesis without the model structure, indicating that no replication had occurred. Finally, the role of the monolignol γ-carbon oxidation state in lignin polymerization, was studied. Hypothetically, lignin- like polymers could be produced by the plant, using monolignol biosynthetic precursors which exhibit γ-carbonyl groups instead of an alcohol group, like the common lignin monomer. Synthetic lignins produced with ferulic acid, coniferaldehyde and the normal monolignol, coniferyl alcohol, displayed important differences in chemical and physical properties. Both the ferulic acid and coniferaldehyde polymers exhibited almost no saturated inter-unit substructures and very few cyclic structures, both of which are very common in coniferyl alcohol dehydrogenative polymers and natural lignins. This could have significant implications for the formation of an important type of lignin carbohydrate complexes (LCC). Also the hydrophobicity of the alcohol-type polymer was lower than the other two. The biological implications of all these findings are discussed and some suggestions are made to explain how all these factors might affect lignin polymerization and structure in nature. / QC 20100811

The photocatalytic activity of semiconductor metal oxides can be improved by the addition of sensitizer which enhances the band gap by considerable red shift of the absorption edge of semiconductor. In the present study, the effect of ascorbic acid as sensitizer on the photocatalytic activity of titania-silica binary mixtures was studied. The SiO2-TiO2 mixtures having 50wt%Ti:Si composition were prepared with sol-gel method. The surface area and porosity of the samples were modified by using various amounts of polyethylene glycol (PEG) as template. The thin films of the samples were obtained by dip coating of glass plates to colloidal solutions. The samples were characterized by methylene blue adsorption method and UV-Vis spectrophotometry. The photocatalytic activities of the samples were measured with methylene blue degradation, methyl orange degradation and direct water splitting in the presence and absence of ascorbic acid. Increase in the surface area and reaction rate with increasing PEG addition until a threshold value was observed. Highest methylene blue degradation activity was observed for 27g PEG added sol-gel derived film and surface area of this film is measured as 44m2/m2. Ascorbic acid presence shows a significant increase in the photocatalytic degradation activity of methyl orange. The sensitization effect of ascorbic acid was also compared with the effect of EDTA. It was found that the effect of ascorbic acid on the methyl orange degradation rate is significantly higher than the effect of EDTA. However, the effect of EDTA is more pronounced in water splitting reaction.