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Sample records for da goma guar

  1. Efeito da goma guar parcialmente hidrolisada no metabolismo de lipídeos e na aterogênese de camundongos

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    Fernandes, Luciana Rodrigues; Xisto,Marilene Diniz; Penna,Michele Groenner; Matosinhos,Izabela Mascarenhas; Leal,Matheus Calab; Portugal,Luciane Rodrigues; Leite, Jacqueline Isaura Alvarez

    2006-01-01

    OBJETIVO: Observar os efeitos da goma guar parcialmente hidrolisada no metabolismo de colesterol e na formação de placa aterosclerótica em aorta de camundongos deficientes no receptor LDL, euglicêmicos ou com hiperglicemia induzida por estreptozotocina. MÉTODOS: Trinta e seis camundongos deficientes para o receptor de LDL foram divididos em quatro grupos de nove animais: grupos euglicêmicos, alimentados com dieta aterogênica padrão (controle euglicêmico) ou suplementada com 7,5% de goma guar ...

  2. Efeito terapêutico da fibra goma-guar parcialmente hidrolisada na constipação intestinal funcional em pacientes hospitalizados

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    Belo,Geise Maria da Silva; Diniz, Alcides da Silva; Pereira,Ana Paula Campos

    2008-01-01

    Avaliação do impacto da fibra goma-guar parcialmente hidrolisada na constipação intestinal funcional em pacientes hospitalizados. Ensaio clínico com 64 adultos, randomizados para duas dietas: grupo 1 dieta laxante (± 30 g de fibras) e grupo 2 mesma dieta + 10 g de fibra goma-guar parcialmente hidrolisada, durante 15 dias. A dieta laxante ou acrescida da referida fibra reduziu em 78% a constipação intestinal funcional, assim como sua adição não provocou efeito adicional na freqüência evacuatór...

  3. Efeitos da goma guar (cyamopsis tetragonolosa) sobre a ingestão de alimentos, lipidemia e glicemia em ratos normais e diabeticos

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    Andrea Cristina Dario Frias

    1996-01-01

    Resumo: Goma guar, derivada do endosperma de sementes de Cyamopsis tetragonoloba foi utilizada nesta pesquisa sendo formada de 75% de fibra solúvel, 7,6% de fibra insolúvel, 2,16% de proteína bruta, 0,78% de lipídios totais, 0,54% de cinza e 9,55% de umidade. O tamanho das partículas (granulometria) e a viscosidade da goma utilizada durante os ensaios, foram determinadas. Quanto ao tamanho das partículas, verificou-se que 98,6% foram menores que 200?m. A viscosidade foi influenciada pelo pH e...

  4. Efeito terapêutico da fibra goma-guar parcialmente hidrolisada na constipação intestinal funcional em pacientes hospitalizados Effect of partially hidrolized guar-gum in the treatment of functional constipation among hospitalized patients

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    Geise Maria da Silva Belo

    2008-03-01

    Full Text Available Avaliação do impacto da fibra goma-guar parcialmente hidrolisada na constipação intestinal funcional em pacientes hospitalizados. Ensaio clínico com 64 adultos, randomizados para duas dietas: grupo 1 dieta laxante (± 30 g de fibras e grupo 2 mesma dieta + 10 g de fibra goma-guar parcialmente hidrolisada, durante 15 dias. A dieta laxante ou acrescida da referida fibra reduziu em 78% a constipação intestinal funcional, assim como sua adição não provocou efeito adicional na freqüência evacuatória, consistência fecal, uso de laxativos, embora tenha reduzido a sintomatologia gastrointestinal. Fibras devem ser utilizadas no tratamento da constipação intestinal funcional; entretanto, a suplementação com fibra goma-guar parcialmente hidrolisada precisa ser melhor investigada.The effect of hydrolyzed partially guar-gum was evaluated in the treatment of functional constipation among hospitalized patients. Following a randomized blind controlled-trial 64 adults were allocated to two groups: one received daily high-fiber diet (@ 30 g and the other similar diet plus 10 g of hydrolyzed partially guar-gum, during 15 days. Dietary fiber reduced functional constipation by 78.0%. Hydrolyzed partially guar-gum did not show any additional effect in defecation frequency, fecal consistence, need of laxative drug use, although a reduction in bowel complaints. Dietary fiber may be used in the treatment of functional constipation. However the therapeutic role of hydrolyzed partially guar-gum should be further investigated.

  5. Efeito da goma guar parcialmente hidrolisada no metabolismo de lipídeos e na aterogênese de camundongos Effect of partially hydrolyzed guar gum on lipid metabolism and atherogenesis of mice

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    Luciana Rodrigues Fernandes

    2006-10-01

    Full Text Available OBJETIVO: Observar os efeitos da goma guar parcialmente hidrolisada no metabolismo de colesterol e na formação de placa aterosclerótica em aorta de camundongos deficientes no receptor LDL, euglicêmicos ou com hiperglicemia induzida por estreptozotocina. MÉTODOS: Trinta e seis camundongos deficientes para o receptor de LDL foram divididos em quatro grupos de nove animais: grupos euglicêmicos, alimentados com dieta aterogênica padrão (controle euglicêmico ou suplementada com 7,5% de goma guar parcialmente hidrolisada (goma guar parcialmente hidrolisada euglicêmico e grupos hiperglicêmicos alimentados com dieta aterogênica padrão (controle hiperglicêmico ou suplementada com 7,5% de goma guar parcialmente hidrolisada (goma guar parcialmente hidrolisada hiperglicêmico. Após quatro semanas de experimento foram medidos: ingestão alimentar, ganho de peso, glicemia, colesterol plasmático e hepático, assim como lesão aterosclerótica na aorta torácica e abdominal. RESULTADOS: Os resultados mostram que a suplementação de goma guar parcialmente hidrolisada levou ao aumento do colesterol hepático e plasmático em animais euglicêmicos, mas sem aumento na área de lesão aterosclerótica na aorta. Em animais hiperglicêmicos, a redução no colesterol plasmático não foi estatisticamente significante, mas no que se refere à lesão da aorta, observou-se redução significante. CONCLUSÃO: Os resultados sugerem que a goma guar parcialmente hidrolisada pode reduzir a aterosclerose associada ao Diabetes Mellitus tipo 1.OBJECTIVE: The objective of this study was to observe the effects of partially hydrolyzed guar gum on cholesterol metabolism and atherosclerosis in the aorta of euglycemic and streptozotocin-induced hyperglycemic LDL receptor deficient mice. METHODS: Thirty six LDL receptor deficient mice were divided into 4 groups of 9 animals: euglycemic groups fed on hypercholesterolemic diet without or supplemented with 7.5% of

  6. INFLUENCIA DE GOMA XANTAN Y GOMA GUAR SOBRE LAS PROPIEDADES REOLÓGICAS DE LECHE SABORIZADA CON COCOA INFLUÊNCIA DA GOMA XANTANA E GUAR SOBRE AS PROPRIEDADES REOLÓGICAS DO LEITE AROMATIZADO COM CACAU INFLUENCE OF GUM XANTHAN AND GUAR ON THE RHEOLOGICAL PROPERTIES OF COCOA- FLAVORED MILK BEVERAGE

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    MÓNICA M. OSPINA

    2012-06-01

    Full Text Available En las bebidas lácteas son utilizados diferentes hidrocoloides con el fin de estabilizar el sistema líquido, en este sentido es necesario determinar la interacción entre algunos hidrocoloides en la matriz alimenticia. El objetivo de este trabajo fue evaluar 3 estabilizantes: goma guar, goma xantan y carragenina kappa en leche saborizada con cocoa alcalina. Inicialmente fue estimada la mezcla óptima entre estos estabilizantes. La variable respuesta utilizada fue viscosidad, en la cual la evaluación de tixotropía tuvo en cuenta los índices: adelgazamiento, recuperación y tixotropía. Los análisis reológicos y fisicoquímicos fueron realizados en un periodo de dos semanas. La mejor mezcla de hidrocoloides fue 70% y 30% para goma xantan y goma guar, respectivamente. La concentración ideal fue determinada bajo 3 tratamientos: T1:0,08%, T2:0,1% y T3:0,12% para el sistema de leche saborizada con cocoa. Los resultados del análisis reológico muestran diferencia significativa (pNas bebidas lacteas são utilizados diferentes hidrocolóides para a estabilização do líquido, neste sentido, é necessário determinar a interação entre alguns hidrocolóides na matriz alimentar. O objetivo deste estudo foi avaliar três estabilizadores: a goma guar, goma xantana e carragena kappa no leite aromatizado com cacau alcalino. Inicialmente, estimase a combinação ideal entre esses estabilizadores. A variável resposta utilizada foi a viscosidade, em que a avaliação levou em conta os índices de tixotropia: perda de peso, recuperação e tixotropia. A análise reológica e físico-química foram realizadas em um período de duas semanas. A melhor mistura de hidrocolóides foi de 70% e 30% de goma xantana e goma guar, respectivamente. A concentração ideal foi determinada em três tratamentos: T1:0,08%, T2:0,1% y T3:0,12%, para o sistema de leite aromatizado com cacau. Resultados das análises reológicas mostram uma diferença significativa (p

  7. AVALIAÇÃO DA ADIÇÃO DE GOMA GUAR E SAL NA ABSORÇÃO DE ÁGUA E NA QUALIDADE DE MACARRÃO INSTANTÂNEO

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    Maria Gabriela VERNAZA

    2012-08-01

    Full Text Available Atualmente, todas as técnicas utilizadas para caracterizar a farinha de trigo são referentes ao processo de panificação sendo pouco encontrados dados específicos para a produção de macarrão instantâneo ou de massas alimentícias em geral. O mercado mundial de macarrão instantâneo vem crescendo a taxas relativamente altas. O objetivo deste trabalho foi estudar o efeito da adição de sal e goma guar nas propriedades tecnológicas de macarrão instantâ- neo, além de estudar uma relação entre a absorção de água obtida nos farinogramas e a absorção de água ótima para produção de macarrão instantâneo quando adicionados sal e goma guar. Para obtenção dos macarrões foi utilizado um delineamento central composto rotacional 22 , permitindo a análise dos resultados pela Metodologia de Superfície de Resposta. Os resultados mostraram que a adição de goma guar (0-1,5 % e sal (0-3 % à formulação de macarrão instantâneo alteraram as propriedades da massa e a qualidade do produto final. Os maiores valores de absorção de gordura e os menores valores de firmeza foram obtidos quando utilizados valores médios das duas variáveis (0,5-1% goma guar e 1,12-1,80% sal. Foi possível encontrar uma relação entre a absorção de água obtida no farinógrafo com a adi- ção de água ótima necessária para a produção de macarrão instantâneo de boa qualidade. As superfícies de resposta indicaram que a absorção de água da massa foi menor quando utilizados valores baixos de gomar guar (0-0,375% e altos de sal (1,5-3%.

  8. Avaliação da Goma Guar no desenvolvimento de comprimidos matriciais de liberação controlada de teofilina

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    Edilene Gadelha de Oliveira; Rosana de Sousa Campos; Anaiara Silva Machado; Juliana Fernandes Pereira; Tamara Gonçalves de Araújo

    2015-01-01

    Resumo O objetivo desse estudo foi formular e avaliar comprimidos de liberação controlada. Comprimidos de liberação controlada de teofilina foram preparadas pelo método de compressão direta usando dois polímeros como, o HPMC K 100M (polímero hidrofílico) e a Goma Guar (Polímero natural), isolado ou em mistura (GG:HPMC 3:1) e GG:HPMC 1:3). Os comprimidos foram caracterizados através do peso médio, diâmetro, altura, dureza, friabilidade. Todos os resultados estiveram em conformidade com os limi...

  9. Effect of guar gum supplementation on lipidic and glycidic metabolic control and body mass index in type 2 diabetes Efeito da suplementação com goma guar no controle metabólico lipídico e glicídico e no índice de massa corporal em diabéticos do tipo 2

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    Mirela dos Santos Ourique Figueiredo

    2006-04-01

    Full Text Available OBJECTIVE: To evaluate the effects of guar gum supplementation in the metabolic control and body mass index (BMI of type 2 diabetic patients. METHODS: A total of 17 (12 women and 5 men participants ingested 10 grams of fiber supplement daily for three months. Changes in BMI and the biochemical parameters (fasting glycemia, glycosilated hemoglobin (HbA1c, total plasma cholesterol and triglycerides were evaluated at the beginning and the end of the study. RESULTS: No changes in mean BMI (p=0.770, mean fasting glycemia (p=0.09 or triglyceride levels were observed. However, significant increases in HbA1c levels were observed (pOBJETIVO: Avaliar os efeitos da suplementação de goma guar no controle metabólico e índice de massa corporal (IMC em pacientes portadores de diabetes do tipo 2. MÉTODOS: Um total de dezessete participantes (doze mulheres e cinco homens receberam a suplementação diária de dez gramas do suplemento de fibra durante três meses. Alterações no IMC e nos parâmetros bioquímicos (glicemia de jejum, hemoglobina glicada (HbA1c, colesterol plasmático total e triglicérides foram avaliadas no início e ao final do estudo. RESULTADOS: Não foram verificadas alterações nos valores médios de IMC (p=0,770, glicemia de jejum (p=0,09 ou triglicérides (p=0,06. No entanto, foi observado aumento significativo (p<0,001 dos níveis de HbA1c após a ingestão dos suplementos de goma guar. Análise posterior indicou que cinco participantes que tiveram valores médios de glicemia de jejum e de HbA1c mais altos tiveram uma redução significativa (p=0,03 da glicemia de jejum ao final do estudo. Uma redução significativa (p<0,001 na concentração de colesterol total foi observada após os três meses de suplementação com a goma guar. CONCLUSÃO: A suplementação dietética de goma guar (10g/dia a pacientes portadores de diabetes tipo 2, com sobrepeso, proporcionando uma ingestão total de fibra próxima de 20g por dia, não foi

  10. ELABORAÇÃO DE SALSICHAS UTILIZANDO GOMA GUAR E GOMA XANTANA EM SUBSTITUIÇÃO AO AMIDO DE MANDIOCA (MANIHOT ESCULENTA

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    Crispin Humberto GARCIA-CRUZ

    2009-07-01

    Full Text Available

    RESUMO: Foram elaboradas salsichas utilizando uma formulação padrão, na qual foi usado amido de mandioca na concentração de 2%, substituindo posteriormente por 1% das gomas guar e xantana. Para estes três tipos de salsichas foram determinadas a estabilidade ao calor, a análise da textura e a análise sensorial. Foram enlatadas e armazenadas por 90 dias à temperatura ambiente. Após este período foi determinada a concentração de gordura liberada na salmoura. Os resultados obtidos foram analisados estatisticamente e foi observado que as salsichas elaboradas com os hidrocolóides acima mencionados apresentaram a mesma estabilidade ao tratamento térmico e não apresentaram diferenças significativas em relação ao painel de provadores. Entretanto, as salsichas enlatadas preparadas com goma xantana retiveram maior quantidade de gordura, proporcionando um produto de melhor aparência. PALAVRAS-CHAVE: Hidrocolóides; elaboração de salsichas; emulsões de carne.

  11. Obtenció, caracterització i fabricació d’una solució gel de goma Guar per a ús oftàlmic

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    Bautista Reverter, Sara

    2008-01-01

    L’objectiu del projecte és descriure el procés d’obtenció, caracterització i fabricació d’una solució gel de goma Guar per a ús farmacèutic. L’obtenció i caracterització de la fórmula és va dur a terme en els laboratoris Alcon. Per a l’obtenció i caracterització d’una solució gel de goma Guar, s’ha realitzat un estudi de la estabilitat tèrmica a l’autoclau de solucions de la goma Guar purificada i no purificada. S’ha provat la eficàcia del mètode utilitzat al laboratori per a l...

  12. Effect of the ionizing radiation of the {sup 60}Co on the radiological properties of guar gum and carboxymethylcellulose for the food industry use; Efeito da radiacao ionizante de {sup 60}Co sobre propriedades radiologicas da goma guar e carboximetilcelulose para uso na industria alimenticia

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    Vieira, Fernando Fabris; Mastro, Nelida Lucia del [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

    2002-07-01

    Hydrosoluble polysaccharides or gums are long chain polymers that dissolve or disperse in water. When added to foods, they change rheological characteristics, stabilize emulsions, promote particle suspension, control crystallization and inhibit sineresis of processed foods. Guar gum is an hydro soluble polysaccharide obtained from the seed of Cyamopsis tetragonolobus. Carboxy-methylcellulose (CMC) is an homopolisaccharide prepared by the treatment of alkaline cellulose with sodium monochloroacetate. This work presents the results of the study of radiation effects on the viscosity of guar gum and CMC used for the food industry when irradiated with {sup 60} Co ionizing radiation. (author)

  13. Caracterización y estudios de digestión in vitro de extrudidos de almidón-goma guar

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    Borries Medrano, Erich von

    2015-01-01

    En la presente investigación se elaboraron extrudidos de almidón-goma guar. Las muestras se formularon empleando un modelo estadístico de Box-Behnken con tres variables: porcentaje de humedad (20-30%), concentración de goma guar (0-2.5% w/w) y temperatura de extrusión (110-140 °C). La morfología, el índice de expansión, la viscosidad y la cristalinidad de los extrudidos fueron analizados a través de la metodología de superficie de respuesta (RMS). Las muestras extrudidas presentaron índice...

  14. Estabilidade de géis de amido de milho normal, ceroso e com alto teor de amilose adicionados de gomas guar e xantana durante os processos de congelamento e descongelamento Freeze-thaw stability of normal, waxy and high amylose corn starch gels with added guar and xanthan gums

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    Fernanda Hart Weber

    2008-06-01

    Full Text Available O objetivo do presente trabalho foi estudar os efeitos das gomas guar e xantana sobre a estabilidade dos géis de amido de milho normal, ceroso e com alto teor de amilose submetidos aos processos de congelamento e descongelamento. Os géis desses amidos, com concentração total de sólidos de 10% e adicionados das gomas (0,15; 0,50; 0,85 e 1%, foram submetidos a 5 ciclos de congelamento (20 horas a -18 °C e descongelamento (4 horas a 25 °C, com exceção dos géis com alto teor de amilose, que foram submetidos a apenas 1 ciclo, devido à perda da estrutura de gel. A determinação da sinérese (porcentagem de água liberada foi realizada pela diferença entre a massa inicial e a massa final das amostras. O gel de amido de milho normal liberou 74,45% de água, sendo que a adição de 1% da goma xantana reduziu significativamente a sinérese para 66,43%. A adição de 0,85 e 1% da goma xantana também reduziu a sinérese dos géis de amido ceroso. O menor teor de sinérese foi obtido com a utilização de 1% de goma xantana ao gel de amido de milho com alto teor de amilose, evidenciando a ação crioprotetora desta goma.The objective of the present work was to study the effects of guar and xanthan gums on the stability of normal, waxy and high amylose corn starch gels, submitted to freeze-thaw processes. The gels of these starches with a total solids content of 10% and added gums (0.15;0.50;0.85and1%, were submitted to 5 freezing (20 hours, -18 °C and thawing (4 hours, 25 °C cycles, with exception of the high amylose gels that were submitted to only 1 cycle. Syneresis (% water released was determined by the difference between the initial and final masses of the samples. The normal corn starch gel released 74.45% water and the addition of 1% xanthan gum significantly reduced syneresis to 66.43%. The incorporation of 0.85 and 1% xanthan gum also reduced syneresis of waxy starch gels. The lowest level of syneresis was reached with the use of 1

  15. Doce cremoso de goiaba adicionado de goma guar e seu efeito hipoglicêmico em indivíduos sadios e diabéticos

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    LIMA Keila S.C.

    1999-01-01

    Full Text Available Estudos mostram que as fibras solúveis no organismo desempenham melhor controle glicêmico, redução do colesterol sérico, retardam o esvaziamento gástrico, podendo, também, ser metabolizadas no intestino, gerando energia. Empregou-se doce cremoso de goiaba com 1,89% de goma guar, como fonte de fibra solúvel, em indivíduos sadios e diabéticos. Os resultados do Teste Oral de Tolerância à Glicose (TOTG, em 50% dos indivíduos sadios, mostraram que a ingestão simultânea do produto com 4,34g de fibra solúvel ao TOTG promoveu uma significativa redução a nível de 5% (P > 0,05 na glicose plasmática aos 60, 90 e 120 minutos. Houve uma redução significativa (P > 0,05 na glicose plasmática nos indivíduos diabéticos, que receberam o produto com 4,34g de fibra solúvel no TOTG, aos 60 e 120 minutos. O doce cremoso de goiaba por conter 2,89% de fibra solúvel, apresentar baixo valor calórico, ser pronto para o consumo, pode servir como opção para indivíduos sadios e diabéticos.

  16. Hydrolyzed collagen, modified starch and guar gum addition in turkey ham Adição de colágeno hidrolisado, amido modificado e goma guar em presunto de peru

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    Rosa Cristina Prestes

    2012-07-01

    Full Text Available The main problems observed in cooked hams are bad sliceability and excessive fluid loss after cooking. To reduce these problems the industry uses non-meat ingredients such as soy protein and carrageenan, but under Brazilian law, it is not allowed to add starch or modified starch in hams. Three ingredients were tested in the present research: modified starch (0 to 2.0%, gum guar (0 to 0.30% and hydrolyzed collagen (0 to 2.0%, following a 2³ full factorial design with five repetitions in the central point. The guar gum produced low resistance to reheating, however in losses by cooling, the results were adequate. The hydrolyzed collagen tested did not give satisfactory results, showing low acceptance due to formation of gel in the ham and high losses. The developed products were not different from the commercial product in relation to texture (P>0.05. The formulation F6 (2.0% of modified starch was the one with the best results and greater acceptance as detected by the tasters. Based on the results obtained it seems appropriate to propose the legal permission of starch in ham or the creation of a new class of product in which starch addition would be allowed.Os principais problemas observados em presuntos são a má fatiabilidade e a perda excessiva de líquidos após o cozimento. Para reduzir esses problemas, a indústria utiliza ingredientes não cárneos, tais como a proteína de soja e a carragena, porém, segundo a legislação brasileira, não é permitida a adição de amido ou amido modificado. Neste trabalho, foram testados três ingredientes, em presunto cozido de peru: amido modificado (0 a 2,0%, goma guar (0 a 0,30% e colágeno hidrolisado (0 a 2,0%, seguindo um delineamento fatorial completo 2³ com cinco repetições no ponto central. A goma guar apresentou baixa resistência ao reaquecimento, no entanto, nas perdas por resfriamento, os resultados foram adequados. O colágeno hidrolisado testado não proporcionou resultados satisfat

  17. Caracterização tecnológica de sobremesas lácteas achocolatadas cremosas elaboradas com concentrado protéico de soro e misturas de gomas carragena e guar Technological characterization of creamy chocolate dairy desserts prepared with whey protein concentrate and a mixture of carrageenan and guar gum

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    Patrícia Hideko Lemos Nikaedo

    2004-09-01

    Full Text Available O consumo de sobremesas lácteas tem apresentado importante crescimento nesta última década, justificado pelo progresso tecnológico em ingredientes e processos. Neste trabalho efetuou-se a caracterização físico-química e sensorial de sobremesas lácteas achocolatadas cremosas, nas quais o concentrado protéico de soro - CPS (3,0; 2,0 e 1,0% foi usado com o leite em pó integral (5,0; 6,0 e 7,0%, carragena (0,05; 0,15 e 0,25%, goma guar (0,25; 0,15 e 0,05%, chocolate em pó (2,8%, açúcar (11,5% e sorbato de potássio (0,08%. Os resultados mostram que é viável utilizar o CPS em substituição ao leite em pó, oferecendo um produto com menores teores de gordura e de sólidos totais, e maior teor de proteínas. O produto apresentou melhor qualidade nutricional, além da redução calórica, favorecendo seu consumo por pessoas preocupadas com a saúde. A sobremesa elaborada com 1,00% de CPS, 7,00% de leite em pó, 0,05% de carragena e 0,25% de goma guar foi considerada a melhor pelos provadores, com aceitabilidade acima do valor 4 (bom.The consumption of dairy desserts has boomed in the last few decades, due to the technological progress in the development of ingredients and processes. In this study the physicochemical and sensory characterization of creamy chocolate dairy desserts were carried out. Whey powder concentrate - WPC (3.0; 2.0 and 1.0% was used with whole milk powder (5.0; 6.0 and 7.0%, carrageenan (0.05; 0.15 and 0.25%, guar gum (0.25; 0.15 and 0.05%, cocoa powder (2.8%, sugar (11.5% and potassium sorbate (0.08%, according to the trial. The results showed that it is possible to use WPC, replacing whole milk powder, and therefore creating a product with low fat and total solids, and high protein content. The final product presented better nutritional quality, besides reduced caloric value, which favors the consumption by people concerned with health. The experimental dairy dessert prepared with 1.00% WPC, 7.00% whole milk

  18. GUAR GUM EFFECTS ON BLOOD SERUM LIPIDS AND GLUCOSE CONCENTRATIONS OF WISTAR DIABETIC RATS1

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    Andrea DARIO FRIAS

    1998-05-01

    Full Text Available The effects of guar gum derived from the endosperm of Cyamopsis tetragonoloba (75% soluble fiber, 7.6% insoluble fiber, 2.16% crude protein, 0.78% total lipids, 0.54% ash and 9.55% moisture on diabetic rats were studied concerning food intake, body weight gain, blood serum cholesterol, triacylglycerols, glucose, LDL-, and HDL-cholesterol concentrations. The effect of gum on indexes of protein absorption and utilization was also investigated. Diets containing 0%, 10% and 20% (w/w guar gum were fed to diabetic rats for 28 days. In spite of the fact that diabetes elevated blood lipids in all animals, guar gum diet significantly decreased (p Os efeitos da goma guar derivada do endosperma de Cyamopsis tetragonoloba (75% fibra solúvel, 7,6% fibra insolúvel, 2,16% proteína bruta, 0,78% lipídios totais, 0,54% cinza e 9,55% umidade foram estudados em relação à ingestão de alimento, ganho de peso corporal, concentrações séricas de colesterol, triacilgliceróis, glicose, HDL e LDL-colesterol. O efeito da goma sobre índices de absorção e utilização de proteína também foi investigado. Dietas contendo 0%, 10% e 20% de goma guar foram utilizadas na alimentação de ratos diabéticos por 28 dias. Apesar do diabetes ter elevado os lipídios sangüíneos em todos animais, as dietas com goma guar decresceram significantemente (p <0,05 as concentrações séricas de colesterol e triacilgliceróis. Além disso, foi encontrado um aumento no nível de HDL-colesterol, com uma elevação substancial na relação de HDL/LDL colesterol. O resultado mais significativo deste ensaio, foi a drástica redução da glicose sangüínea nos ratos diabéticos tratados com dietas contendo goma guar. A goma promoveu uma melhora geral nas condições dos animais diabéticos, no ganho de peso corporal e nos índices de absorção e utilização protéica. Os resultados desta pesquisa sugerem que a goma guar, em concentrações igual ou superiores a 10%, podem ser

  19. Efeitos da galactomanana de Cyamopsis tetragonolobus na osteoartrite induzida por transecÃÃo do ligamento cruzado anterior em ratos

    OpenAIRE

    Rondinelle Ribeiro Castro

    2008-01-01

    No modelo de osteoartrite (OA) induzida por transecÃÃo do ligamento cruzado anterior em ratos (TLCA), havÃamos demonstrado que a goma guar (GG), uma galactomanana extraÃda das sementes de Cyamopsis tetragonolobus goma guar, apresenta atividade analgÃsica em magnitude semelhante à exibida pelo Hilano G-F 20, um derivado do Ãcido hialurÃnico utilizado em terapia intra-articular da OA humana. Utilizando o referido modelo, objetivamos desenvolver um mÃtido bioquÃmico paramÃtrico para avaliaÃÃo da...

  20. Influência da natureza do rejeito agroindustrial fermentado por Xanthomonas axonopodis pv. manihotis nas propriedades das gomas xantana resultantes

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    Denilson de Jesus Assis

    2014-01-01

    Full Text Available Um destino para resíduos agro-industriais é usá-los como substratos fermentescíveis, diminuindo o custo na produção de produtos com alto valor agregado. Este trabalho avaliou a influência da natureza dos resíduos fermentescíveis e das cepas de Xanthomonas sobre a produção e propriedades do biopolímero resultante. A produção foi realizada em agitador orbital (250 rpm / 28 °C / 120 h por fermentação de sacarose (controle, glicerina residual do biodiesel e resíduo líquido de sisal. Tanto a composição do substrato como as cepas mostraram um forte efeito sobre a produção (0,36-2,40 gL- 1, viscosidade aparente (13,73 para 36,31 mPa.s e massa molecular (2,1-5,9 × 10(6 Da da goma de xantana resultante, não influenciando o comportamento pseudoplástico de soluções aquosas dos biopolímeros.

  1. Conservation of papaya minimally processed with the use of edible coating based on xanthan gum Conservação de mamão minimamente processado com uso de revestimento comestível à base de goma xantana

    Directory of Open Access Journals (Sweden)

    William Renzo Cortez-Vega

    2013-09-01

    ,25% de goma guar e 1% de quitosana (T5. Tais revestimentos foram preparados em solução aquosa e adicionados a eles 1% do plastificante glicerol. No tratamento controle e nos pedaços de mamão revestidos foram analisados a perda de massa, firmeza, pH, acidez titulável cor e os seguintes grupos de micro-organismos: psicrófilos, Salmonella spp., coliformes totais e termotolerantes. Os diferentes revestimentos à base de goma xantana foram eficientes na conservação do mamão “Formosa” minimamente processado, em relação à amostra controle. A adição de goma guar ao revestimento de xantana influenciou negativamente na perda de massa e nos parâmetros de cor, luminosidade, a* e b*. A adição de quitosana (T3 influenciou beneficamente na redução da perda de massa, manutenção da luminosidade e menor redução nos parâmetros a* e b*, entretanto, não foi observado efeito antimicrobiano. Assim, sugere-se como revestimento comestível de mamão “Formosa” minimamente processado o revestimento composto somente de goma xantana (T2, o qual propiciou redução da perda de massa, manutenção da luminosidade e b* e menor redução no a*. Entretanto, experimentos visando à manutenção da firmeza, pH e acidez deverão ser futuramente realizados.

  2. PROSPECÇÃO TECNOLÓGICA: APLICAÇÃO DA GOMA DO CAJUEIRO (Anacardium occidentale EM NANOTECNOLOGIA

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    celia cunha e silva

    2013-12-01

    Full Text Available O cajueiro (Anacardium occidentale, da família Anacardiaceae, é uma planta originária do Norte e Nordeste do Brasil, com arquitetura de copa tortuosa e de diferentes portes, bastante cultivada no Brasil, principalmente no Nordeste. O objetivo deste trabalho foi realizar uma prospecção, com busca de precedência e apresentar uma visão geral do estado atual de desenvolvimento científico e tecnológico relacionado à aplicação da goma do cajueiro na nonotecnologia, baseado no número de patentes depositadas e de artigos publicados. A prospecção foi realizada no Banco Europeu de Patentes (Europen Patent Office - EPO, no Banco da Organização Mundial de Propriedade Intelectual (World Intellectual Organization - WIPO, no Banco Americano de Marcas e Patentes (United States Patent and Trademark Office - USPTO e no Banco de dados do Instituto Nacional de Propriedade Industrial do Brasil – INPI, bem como na base de periódicos, Web of Science. O Brasil detém o maior número de artigos científicos envolvendo a Anacardium ocidentale, enquanto o Japão se sobressai na proteção desta pesquisa. Foi observado que das patentes depositadas nas referidas bases, mais da metade foram depositadas no período de 2000 a 2012, demostrando um aumento nas pesquisas relacionadas com o cajueiro nos últimos 12 anos, e que a maior parte das patentes possuem código de classificaçao de patente A61K e A61P que estão relacionadas a necessidades humanas.

  3. Microbiota benefits after inulin and partially hydrolized guar gum supplementation: a randomized clinical trial in constipated women Beneficios en la microbiota intestinal después de la suplementación con inulina y la goma guar parcialmente hidrolizada: un ensayo clínico aleatorizado en mujeres con estreñimiento

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    D. Linetzky Waitzberg

    2012-02-01

    Full Text Available Introduction: Prebiotics positively affect gut microbiota composition, thus improving gut function. These properties may be useful for the treatment of constipation. Objectives: This study assessed the tolerance and effectiveness of a prebiotic inulin/partially hydrolyzed guar gum mixture (I-PHGG for the treatment of constipation in females, as well as its influence on the composition of intestinal microbiota and production of short chain fatty acids. Methods: Our study enrolled 60 constipated female health worker volunteers. Participants reported less than 3 bowel movements per week. Volunteers were randomized to treatment with prebiotic or placebo. Treatment consisted of 3 weeks supplementation with 15 g/d IPHGG (fiber group or maltodextrin (placebo group. Abdominal discomfort, flatulence, stool consistency, and bowel movements were evaluated by a recorded daily questionnaire and a weekly interview. Changes in fecal bacterial population and short chain fatty acids were assessed by real-time PCR and gas chromatography, respectively. Results: There was an increased frequency of weekly bowel movements and patient satisfaction in both the fiber and placebo groups with no significant differences. Total Clostridium sp significantly decreased in the fiber group (p = 0.046 and increased in the placebo group (p = 0.047. There were no changes in fecal short chain fatty acid profile. Conclusions: Consumption of I-PHGG produced clinical results comparable to placebo in constipated females, but had additional protective effects on gut microbiota by decreasing the amount of pathological bacteria of the Clostridium genera.Introducción: Los prebióticos influyen positivamente en la composición de la microbiota intestinal, mejorando así la función intestinal. Estas propiedades pueden ser útiles para el tratamiento del estreñimiento. Objetivos: Este estudio evaluó la tolerancia y la eficacia de una mezcla de prebiótico inulina con la goma guar

  4. Comportamento reológico de recheios para chocolates em base gordurosa e formulados com polpas de frutas e gomas

    OpenAIRE

    Alline Áurea do Amaral

    2013-01-01

    Recheios são componentes utilizados na indústria de chocolates e de confeitos. Os recheios para chocolates podem ser elaborados com gorduras vegetais, açúcar fondant, creme de leite, amido ou com preparados de frutas contendo gomas. Nesses produtos, as gomas podem ser empregadas com a função de estabilizante, espessante ou como redutores de gordura, minimizando alterações sensoriais, de textura e de separação de fases. A goma guar vem sendo utilizada em muitos produtos alimentícios. A goma ch...

  5. Desenvolvimento, parâmetros físico-químicos e avaliação sensorial de sobremesas lácteas elaboradas com soro de queijo e gomas

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    Janaína de Souza

    2013-08-01

    Full Text Available Soro de queijo é um subproduto da indústria de laticínios de elevada carga orgânica, que se considerado resíduo deverá ser encaminhado a estação de tratamento de efluentes, antes do descarte em corpos hídricos, porém as proteínas do soro apresentam excelente qualidade nutricional. A produção de sobremesas lácteas a base de soro de queijo é uma alternativa de aproveitamento deste resíduo visando agregar valor e reduzir os custos das empresas. Portanto, o objetivo desse trabalho foi desenvolver e avaliar as características físico-químicas, reológicas e sensoriais de diferentes formulaçõesde sobremesas lácteas sabor morango elaboradas com soro de queijo e gomas. Foram elaboradas formulações com diferentes concentrações de gomas xantana, carragena, guar e pectina. Os teores médios de umidade, proteínas e lipídios das formulações de sobremesa láctea elaboradas foram de 67%, 7,7% e 5,9%, respectivamente. A avaliação reológica demonstrou comportamento não-newtoniano, com fluxo plástico e tixotropia para todas as formulações de sobremesas lácteas. Na avaliação sensorial, a amostra com 0,3% de goma xantana e 0,2% de goma guar apresentou o maior índice de aceitabilidade dos atributos aparência e textura, além disso, a nota média da impressão global não diferiu significativamente da amostra comercial de sobremesa láctea analisada. Em relação a intenção de compra, 67,5% dos provadores assinalaram que "certamente" ou "provavelmente comprariam" o produto com 0,3% de goma xantana e 0,2% de goma guar caso fosse comercializado. O emprego do soro de queijo na elaboração de sobremesas lácteas é uma alternativa viável sob os aspectos tecnológicos e ambientais para os laticínios.

  6. Goma sifilítica – uma apresentação rara da neurossífilis na idade pediátrica

    OpenAIRE

    do Céu Espinheira, Maria; Soares, Susana; Guardiano, Micaela; Maia, Ana; Rego, Carla; João Gil-da-Costa, Maria; Manuel Campos, Maria; Júlia Eça Guimarães, Maria

    2014-01-01

    Resumo: Apresenta-se o caso de uma criança de seis anos de idade com quadro de cefaleia, alteração do equilíbrio, disartria e vómitos de evolução progressiva ao longo de três semanas. A tomo grafia computorizada cerebral identificou uma lesão da fossa posterior. O estudo etiológico foi direccionado para a exclusão de uma patologia neoplásica ou infecciosa/inflamatória e culminou no diagnóstico de goma sifilítica, corroborado pela identificação de Treponema pallidum no líquor, por técnica de p...

  7. INFLUÊNCIA DA TEMPERATURA NA REOLOGIA DE FLUIDOS DE PERFURAÇÃO PREPARADOS COM CARBOXIMETILCELULOSE, GOMA XANTANA E BENTONITA

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    Klismeryane Costa de Melo

    2013-10-01

    Full Text Available O comportamento reológico dos fluidos de perfuração pode sofrer alterações ao longo da perfuração em função do gradiente de temperatura do poço. A degradação térmica sofrida por alguns aditivos utilizados como viscosificantes restringe a utilização da classe dependendo da temperatura a qual será exposto. Este trabalho apresenta um estudo sobre o comportamento reológico da Goma Xantana (GX, da Carboximetilcelulose (CMC e da Bentonita (BNT em função da temperatura. Os Modelos matemáticos de Ostwald de Waale e o de Herschel-Bulkley foram aplicados para determinar os parâmetros reológicos. O efeito da hidratação dos polímeros e da argila na reologia de soluções aquosas foram previamente estudados. A caracterização reológica foi realizada através de ensaios de reologia, utilizando sistema de cilindros coaxiais, para obtenção das curvas de fluxo. A reologia foi avaliada em função da temperatura para cada um dos aditivos utilizados. Os resultados mostraram que a CMC se solubiliza rapidamente em água, porém apresenta maior degradação quando exposta a temperatura mais elevada. A GX se mostrou apta para ser utilizada em formulações de fluidos que serão usados em poços com gradiente de temperatura mais elevados. A bentonita não apresentou alterações no comportamento reológico em função do gradiente de temperatura estudado.

  8. GOMA 6.0 :

    Energy Technology Data Exchange (ETDEWEB)

    Schunk, Peter Randall; Rao, Rekha Ranjana; Chen, Ken S; Labreche, Duane A.; Sun, Amy Cha-Tien; Hopkins, Matthew M; Moffat, Harry K.; Roach, Robert Allen; Hopkins, Polly L.; Notz, Patrick K.; Roberts, Scott Alan; Sackinger, Philip A.; Subia, Samuel Ramirez; Wilkes, Edward Dean; Baer, Thomas A.; Noble, David R.; Secor, Robert B.

    2013-07-01

    Goma 6.0 is a finite element program which excels in analyses of multiphysical processes, particularly those involving the major branches of mechanics (viz. fluid/solid mechanics, energy transport and chemical species transport). Goma is based on a full-Newton-coupled algorithm which allows for simultaneous solution of the governing principles, making the code ideally suited for problems involving closely coupled bulk mechanics and interfacial phenomena. Example applications include, but are not limited to, coating and polymer processing flows, super-alloy processing, welding/soldering, electrochemical processes, and solid-network or solution film drying. This document serves as a users guide and reference.

  9. Aplicação de modelo matemático às propriedades reológicas de géis mistos de agarose e de goma guar Application of a mathematical model to the rheological properties of agarose-guar gum mixed gels

    Directory of Open Access Journals (Sweden)

    Cristina T. Andrade

    1997-04-01

    Full Text Available Certain biopolymers are capable of forming physically cross-linked gels in aqueous medium, stabilized by forces such as Coulombic, charge transfer, hydrogen bonding, dipole-dipole, van der Waals, and hydrophobic interactions. The mathematical description of these physical networks are difficult, but should contribute to a better understanding of the gelling process. The Clark and Ross-Murphy model was applied to experimental data for agarose-guar gum mixed systems, in which only agarose is the gelling polysaccharide. A computational routine based on the statistical maximum likehood principle was employed to estimate the f, K and a characteristic parameters. Statistical t-test and F-test were used to analyse the set of parameters.

  10. Evaluation of new polysaccharides networks for extended-release purposes: mesquite seed gum (MSG, xanthan gum and chitosan Estudo da utilização de polissacarídeos no desenvolvimento de formulações de liberação prolongada: goma de semente de algaroba, goma xantana e quitosano

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    Carlos César dos Santos Nogueira

    2003-09-01

    Full Text Available The aim of this work was to design new hydrophilic matrix (HM systems by cross-linking Mesquite Seed Gum (MSG, a galactomannan that occurs in the endosperm layer of the seeds of a Brazilian tree,Prosopis juliflora DC, with two well-known polysaccharides with the ability of retarding drug release, chitosan and xanthan gum. This had in mind the idea of using these new compounds in the preparation of extended-release dosage oral forms. The first part of this study was dedicated to the evaluation of MSG in terms of its functionality as a hydrophilic matrix (HM system for extended-release purposes. Next, we started the study of water uptake profile of all polymers of interest (MSG, Xanthan Gum and Chitosan, in the following media: water, SGF and SIF. Following, we searched for the best cross-linking agent between Glutharaldehyde (GA and Hexamethylenediisocyanate (HMDI, which turned out to be the GA. Next step we begun to prepare new hydrophilic matrices of MSG_Chitosan and MSG_Xanthan Gum, with different ratios, 1:1, 1:2 and 2:1. Finally, after deciding which new HM system presented best results, by using statistics tools, we investigated the mechanism controlling the rate release of the model drug, from tablets made with this new matrix. As a final result we concluded that the best combination of polysaccharides was achieved with MSG and Xanthan Gum, with mass ratio of 1:2, using glutharaldehyde aqueous solution as cross-linking agent. It presented a prevalent zero order kinetics, which is a very important feature when thinking about an extended-release oral dosage.O objetivo deste trabalho foi o desenvolvimento de novos sistemas de matrizes hidrofílicas através da formação de ligações cruzadas (cross-linking entre a Goma da Semente da Algaroba (GSA, uma galactomanana que ocorre no endosperma das sementes de uma árvore nativa do Brasil, a Prosopis juliflora DC, e dois polissacarídeos bem conhecidos pela sua habilidade de retardar a libera

  11. Composição e propriedades reológicas da goma do angico (anadenanthera macrocarpa benth Composition and rheological properties of exudate gum from anadenanthera macrocarpa

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    André G. da Silva

    1998-06-01

    Full Text Available A goma do angico foi purificada através de três estágios, cada um deles envolvendo dissolução em água e precipitação em etanol. As duas primeiras precipitações foram efetuadas em presença de NaCl e a última, em ausência. Os teores de umidade, cinza, proteína e cátions foram determinados para a goma nos vários estágios de purificação. A composição do polissacarídeo, obtida por HPLC, foi: 67,8% de arabinose, 24,1% de galactose e 2,0% de ramnose. O teor de 5,9% de ácido urônico foi calculado a partir de titulação condutométrica. Os cátions presentes na goma bruta (Na+, K+, Ca2+, Mg2+ e Fe3+ foram analisados por absorção atômica e gradualmente substituídos por Na+. O teor de proteína, no entanto, não diminuiu significativamente ao longo das purificações, o que pode ser um indicativo de que ela se encontra agregada ao polissacarídeo. O estudo por GPC sugere a presença de um complexo polissacarídeo-proteina de massa molar 7,9 x 10(5 g/mol e de polissacarídeos de massa molar 8,3 x 10(4 g/mol e 2,2 x 10(4 g/mol. A goma do angico apresenta baixa viscosidade e Energia de ativação de fluxo 16,8 kJ/mol, 17,2 kJ/mol e 17,7 kJ/mol, respectivamente para soluções 2%, 3% e 5%. Comparação com outros polissacarídeos indica que a macromolécula é ramificada, mas em menor grau do que a goma arábica e a goma do cajueiro.A pure salt gum was obtained by using a method of purification based on dissolutions in water and precipitation with ethanol, first in presence of NaCl, and later in absence of salt. Characterization was performed by determination of moisture, ash, protein and cations. The composition of the polysaccharide was determined as 67.8% arabinose, 24.1% galactose, 2.0% rhamnose by HPLC and 5.9 % of uronic acid by condutometric analysis. Cations presents in the crude gum (Na+, K+, Ca2+, Mg2+ and Fe3+ were investigated by atomic absorption spectrophotometry and gradually substituted by Na+. Protein was tightly

  12. Resgatando identidades por meio da solidariedade e da literatura: uma análise das personagens Rosálio e Irene em O voo da guará vermelha, de Maria Valéria Rezende

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    Fernanda Aquino Sylvestre

    2014-09-01

    Full Text Available Resumo: Maria Valéria Rezende aborda em O voo da guará vermelha o retrato contemporâneo da miséria, não apenas em termos econômicos, mas principalmente morais. Os personagens carecem de identidade e só a recuperam por meio da solidariedade e da literatura, fantasiando, contando histórias. Diante do exposto, o objetivo deste artigo é traçar algumas considerações acerca dos personagens Rosálio da Conceição e Irene, sobretudo no que diz respeito à construção de suas identidades em um contexto miserável, e mostrar como eles as recuperam por meio do contar e do ouvir histórias. Também pretende-se mostrar como os personagens vencem a situação de miséria, através do papel humanizador da literatura. Palavras-chave: Literatura contemporânea; Maria Valéria Rezende; identidade; papel humanizador da literatura. Abstract: Maria Valeria Rezende discusses in O voo da guará vermelha the contemporary portrait of misery, not only in economic terms, but mostly moral, in which the characters lack their identity and recover it only through solidarity and literature, fantasizing, telling histories. Given the above, the purpose of this paper is to outline some considerations about the characters Rosalio and Irene da Conceição, especially with regard to the construction of their identities in a context of widespread poverty, showing how they recover their identities by telling and hearing stories. This article also aims to show how the characters overcome the misery through the humanizing role of literature. Keywords: Contemporary literature; Maria Valéria Rezende; identity; humanizing role of literature.

  13. EFEITO DA ADIÇÃO DE HIDROCOLÓIDES EM SISTEMAS MODELO CARNE-ÁGUA

    OpenAIRE

    Crispin Humberto GARCIA-CRUZ; Scamparini, Adilma Regina Pippa

    2009-01-01

    RESUMO: Foram testados diferentes tipos de hidrocolóides comerciais num sistema carne-água na proporção 1:2. Utilizaram-se diferentes concentrações (1% a 6%) dos hidrocolóides: carboximetilcelulose de sódio, gelatina, amido de mandioca, amido modificado por fosfatação, goma arábica, goma guar, goma tragacanta, goma xantana, goma locusta, carragena, alginato de sódio, pectina de alto e baixo teor de metoxilação e a mistura das gomas xantana-locusta. Dos resultados obti...

  14. Estimulantes químicos na extração da goma de cajueiro(Anacardium occidentale, L. Chemical stimulants in the extraction of the gum of cashew tree

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    Antônio Calixto Lima

    2001-06-01

    Full Text Available O trabalho foi instalado no campo experimental de Pacajus - Ceará - Brasil, pertencente ao Centro Nacional de Pesquisa de Caju (CNPAT/EMBRAPA, no decurso do ano agrícola 1991 / 1992, tendo como objetivo avaliar o uso de estimulantes químicos na extração da goma de cajueiro (Anacardium occidentale, L., bem como estudar sua interferência sobre safras futuras da referida matéria. Na pesquisa, foram testadas, através de esquema fatorial, concentrações de 0, 15, 30 e 45% de ácido sulfúrico, combinadas com um nível de dimetil sulfóxido (5% mais 5 níveis de ethephon que variaram de 0 a 20% do ácido 2 - cloroetilfosfônico. Obteve-se um aumento generalizado das produções de goma nos meses que se seguiram à primeira operação de estriamentos por efeito dos estimulantes aplicados. O ácido sulfúrico não interferiu na exsudação, enquanto a solução de 15% de ácido 2-cloroetilfosfônico promoveu a melhor resposta sobre a produção de goma.The work was carried out at the Experimental Field Station of the National Institute of Cashew Research (CNPAT/EMBRAPA in Pacajus County, State of Ceará, Brazil, in order to study the influence of chemical stimulants to extract gum from cashew tree (Anacardium occidentale, L., as well as to study its interference on future gum productions. Sulphuric acid concentrations of 0, 15, 30 and 45%, combined with concentrations of 0, 5, 10, 15 and 20% of 2-chloroethylphosphonic acid and 5% dimetil sulphoxide were tested in a factorial design. The influence of the stimulant over the future gum exudation was also assessed. A general increase of gum exudation was obtained in all months following the stimulant applications; sulphuric acid did not increase gum exudation in any of the used concentrations. On the other hand, a 15% concentration of 2-chloroethylphosphonic acid allowed the highest rate of gum exudation.

  15. Efeito do congelamento sobre a microestrutura da massa do pão.

    OpenAIRE

    Fabrício de Souza Resende

    2011-01-01

    A qualidade global da massa de pão congelada por um longo período é um desafio para indústria de panificação. O uso de diferentes técnicas pode ajudar a explicar os danos sofridos à massa de pão durante o congelamento e armazenamento congelado. A presença de água na forma de cristais de gelo foi vista como a principal causa de defeitos à estrutura da massa. Gomas guar e xantana foram incorporadas às massas para contornar os danos causados pelo congelamento. Das análises térmicas conduzi...

  16. EFEITO DA ADIÇÃO DE HIDROCOLÓIDES EM SISTEMAS MODELO CARNE-ÁGUA

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    CRISPIN HUMBERTO GARCIA-CRUZ

    2009-07-01

    Full Text Available

    RESUMO: Foram testados diferentes tipos de hidrocolóides comerciais num sistema carne-água na proporção 1:2. Utilizaram-se diferentes concentrações (1% a 6% dos hidrocolóides: carboximetilcelulose de sódio, gelatina, amido de mandioca, amido modificado por fosfatação, goma arábica, goma guar, goma tragacanta, goma xantana, goma locusta, carragena, alginato de sódio, pectina de alto e baixo teor de metoxilação e a mistura das gomas xantana-locusta. Dos resultados obtidos, selecionaram-se aqueles hidrocolóides que proporcionaram maior estabilidade ao sistema após o cozimento. Os hidrocolóides selecionados foram as gomas guar, xantana, locusta e a mistura xantana-locusta, sendo que, destes, a goma xantana, a goma guar e a goma locusta proporcionaram melhores resultados na estabilidade do sistema ao cozimento (99,0%, 90,5% e 91,0%, respectivamente e a menor sinerese (0,01; 0,08 e 0,10 ml/g de pasta na concentração de 1,0%. Determinou-se também a capacidade emulsificante dos hidrocolóides anteriormente selecionados. Os resultados obtidos mostraram que a goma xantana proporcionou a capacidade emulsificante mais elevada, quando comparada com a capacidade emulsificante obtida com as gomas guar, locusta e a mistura xantana-locusta. PALAVRAS-CHAVE: Hidrocolóides; sistema modelo; emulsão; gomas.

  17. Avaliação pós-vacinal de lobos guarás Chrysocyon brachyurus (Illiger, 1811 contra os vírus da cinomose e parvovirose caninas

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    Maia O.B.

    1999-01-01

    Full Text Available Este estudo teve como objetivos acompanhar a resposta sorológica pós-vacinal de lobos guarás cativos imunizados contra os vírus da cinomose (CDV e da parvovirose (CPV caninas com vacina vírus vivo modificado (VVM produzida para cães domésticos e determinar um programa de vacinação para a espécie. Amostras de soro foram coletadas de 47 lobos com idades variadas, provenientes de seis zôos. Foram utilizados os testes de soroneutralização (SN e inibição da hemaglutinação (HI para mensurar os títulos de anticorpos contra CDV e CPV, respectivamente, sendo testadas 361 amostras para CDV e 353 para CPV. A avaliação pós-vacinal demonstrou que 72% dos espécimes desenvolveram títulos de SN > ou = 100 contra CDV e 98% desenvolveram títulos de HI > ou = 80 contra CPV. Lobos guarás sem histórico de vacinação apresentaram soroconversão após a vacinação. Espécimes com histórico de vacinação e títulos considerados protetores para cães domésticos mantiveram títulos estáveis ao longo de 12 meses após a vacinação. A VVM utilizada (CDV atenuado por passagens em ovos embrionados de aves SPF e posteriormente adaptado às células da linhagem VERO mostrou-se segura para os lobos guarás adultos e filhotes.

  18. Caracterização reológica da goma xantana: influência de íons metálicos univalente e trivalente e temperatura em experimentos dinâmicos Rheological characterization of xanthan gum: influence from univalent and trivalent metallic ions and from the temperature in dynamic experiments

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    Samuel Luporini

    2011-01-01

    Full Text Available As propriedades dinâmicas das soluções aquosas de goma xantana com e sem adição de NaCl ou Al2(SO43.18H2O foram medidas em um reômetro de deformação controlada aplicando ciclos de aquecimento e resfriamento. O tempo de relaxação decresceu com o aumento da temperatura; no entanto, este tempo aumentou com a adição de sal nas soluções de 0,5% em peso de goma xantana, mas diminuiu com a adição de 1%. Durante o aquecimento das soluções de goma xantana pura ocorreu uma mudança de conformação a 51 °C, e durante o resfriamento foi observada a formação de duas estruturas: entre 86 e 47 °C e abaixo de 47 °C. Com a adição de sal não houve mudança conformacional durante o aquecimento, enquanto no resfriamento duas estruturas foram novamente observadas, mas para faixas de temperatura diferentes.The dynamic rheological properties of water xanthan gum solutions with and without the addition of NaCl or Al2(SO43.18H2O were measured in a strain controlled rheometer applying heating and cooling cycles. The terminal relaxation time decreased with increasing temperature. This time increased with the addition of 0.5 wt. (% of salt, but decreased when 1 wt. (% was added. During heating a conformational change occurred at 51 °C and upon cooling two structures were observed between 86 and 47 °C and below 47 °C. When salt was added there was no conformational change during heating, but the two structures again appeared during cooling, though at different temperature ranges.

  19. 76 FR 44811 - Carboxymethyl Guar Gum Sodium Salt and Carboxymethyl-Hydroxypropyl Guar; Exemption From the...

    Science.gov (United States)

    2011-07-27

    ...-0531; FRL-8880-5] Carboxymethyl Guar Gum Sodium Salt and Carboxymethyl- Hydroxypropyl Guar; Exemption... carboxymethyl guar gum sodium salt (CAS Reg. No. 39346-76-4) and carboxymethyl-hydroxypropyl guar (CAS Reg. No... residues of carboxymethyl guar gum sodium salt and carboxymethyl- hydroxypropyl guar. DATES:...

  20. Safety assessment and caloric value of partially hydrolyzed guar gum.

    Science.gov (United States)

    Finley, John W; Soto-Vaca, Adriana; Heimbach, James; Rao, T P; Juneja, Lekh Raj; Slavin, Joanne; Fahey, George C

    2013-02-27

    Guar gum and partially hydrolyzed guar gum (PHGG) are food ingredients that have been available for many years. PHGG is the partially hydrolyzed product from guar gum obtained from the Indian cluster bean (Cyanopsis tetragonolopus). The gum (CAS Registry No. 9000-30-0) is composed of galactomannan, a gel-forming polysaccharide with a molecular weight ranging from 200 to 300 kDa. The intact and partially hydrolyzed forms have multiple food applications. The intact material can be used to control the viscosity, stability, and texture of foods. PHGG is highly soluble and has little physical impact on foods. Both forms are indigestible but are excellent sources of fermentable dietary fiber. The caloric value of intact guar gum is accepted as 2.0, whereas the caloric value of PHGG has not been firmly established. It is the goal of this paper to review the chemistry, safety, in vivo effects, and caloric value of PHGG.

  1. Influência de diferentes aglutinantes na digestibilidade aparente da matéria seca e da proteína, no pacu (Piaractus mesopotamicus arraçoado com rações elaboradas com ou sem vapor Influence of different binders in the apparent digestibility of dry matter and protein in pacu (Piaractus mesopotamicus fed with ration processed with or without steam

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    Maria Angélica Rosa Ribeiro

    1999-07-01

    Full Text Available O trabalho foi realizado no Centro Nacional de Pesquisa de Peixes Tropicais - Cepta, com o objetivo de determinar a influência de vários aglutinantes: carboximetilcelulose, polimetilcarbamida, amido de mandioca, alginato de sódio, polivinilpirrolidona e goma guar, bem como a técnica de processamento, com ou sem vapor, na digestibilidade aparente das frações matéria seca e proteína bruta. Os resultados obtidos demonstraram que a técnica de processamento a que se submete a mistura, durante a confecção de ração para peixes, influencia o coeficiente de digestibilidade aparente das frações matéria seca e proteína bruta, em pacus. Quando da confecção de rações para peixes, houver a necessidade de utilizar-se de aglutinantes, a fim de obter pelletes mais estáveis, recomenda-se, para os equipamentos dotados de câmara de acondicionamento com adição de vapor, a polivinilpirrolidona, e para os sem a adição de vapor, a goma guar.This work was carried out at National Research of Tropical Fishes - Cepta, with the objective to determine the influence of different dietary binders with their respective concentrations: sodium alginate, guar gum, polymethylolcarbamide, polyvinylpyrrolidone, carboxymethylcellulose, cassava starch, and the manufacturing process with or without steam, in the apparent digestibility of protein and dry matter. The results obtained showed that the manufacturing technique during the fish ration process, influences the apparent digestibility coefficient of dry matter and protein in pacu. When binders are required to obtain more stable diet pellets, polyvinylpyrrolidone for equipments with steam addition chambers and guar gum for equipment without steam are recommended.

  2. Textura instrumental de queijo petit-suisse potencialmente probiótico: influência de diferentes combinações de gomas Instrumental texture of probiotic petit-suisse cheese: influence of different combinations of gums

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    Larissa Yukie Maruyama

    2006-06-01

    Full Text Available O efeito de diferentes combinações de gomas sobre os parâmetros de textura instrumental de queijo tipo petit-suisse probiótico foi avaliado. Queijos petit-suisse foram produzidos utilizando-se massa-base de queijo quark preparada com o starter Streptococcus thermophilus e os probióticos Lactobacillus acidophilus e Bifidobacterium longum. Três formulações de queijo petit-suisse foram preparadas, a partir de massa-base de queijo quark adicionada de 0,75% do produto final da mistura de gomas - xantana (X, carragena (C, guar (G, pectina (P: F1 = 2,5X:2,5C:5G; F2 = 2X:3C:5P; F3 = 5C:5G. Os parâmetros avaliados após 1, 7, 14 e 21 dias de armazenamento do produto a 4±1ºC incluíram a contagem de probióticos, a textura instrumental, o pH e a umidade. As populações de probióticos mantiveram-se acima de 6,40 log UFC/g para L. acidophilus e de 7,30 log UFC/g para B. longum. Houve diferença significativa entre as formulações (pThe effect of different combinations of gums over texture parameters of probiotic petit-suisse cheese was evaluated. Petit-suisse cheeses were produced using Quark cheese-base prepared with the starter Streptococcus thermophilus and the probiotics Lactobacillus acidophilus and Bifidobacterium longum. Three formulations of petit-suisse were prepared, using the quark cheese-base added of 0.75% of the final product of the mixture of the hydrocolloids xanthan gum (X, carrageenan gum (C, guar gum (G, pectin (P: F1 = 2,5X:2,5C:5G; F2 = 2X:3C:5P; F3 = 5C:5G. Parameters evaluated after 1, 7, 14, and 21 days of storage of the product at 4±1ºC included microbial counts of probiotic microorganisms, instrumental texture parameters, pH and moisture. Probiotic counts were always above 6.40 log CFU/g for L. acidophilus and above 7.30 log CFU/g for B. longum. The formulations were significantly different (p<0.05 for all the texture parameters, except for firmness of F1. The pH and the moisture were similar for the three

  3. 21 CFR 184.1339 - Guar gum.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Guar gum. 184.1339 Section 184.1339 Food and Drugs... Substances Affirmed as GRAS § 184.1339 Guar gum. (a) Guar gum is the natural substance obtained from the maceration of the seed of the guar plant, Cyamopsis tetragonoloba (Linne) Taub., or Cyamopsis...

  4. Goma de cajueiro (Anacardium occidentale: Avaliação das modificações químicas e físicas por extrusão termoplástica

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    Kelita C. S. Andrade

    2013-01-01

    Full Text Available Países tropicais, como o Brasil, são depositários de uma grande variedade de fontes de polissacarídeos vegetais conhecidos e outros ainda não explorados que possuem grande potencial em aplicações industriais. Alguns estudos reportam a possibilidade de aplicação industrial da goma exsudada do cajueiro em substituição à goma arábica devido à semelhança estrutural e química. Neste estudo propôs-se caracterizar comparativamente algumas propriedades destas duas gomas, antes e após dois tratamentos de extrusão termoplástica. Nos resultados de composição centesimal as amostras de goma de cajueiro in natura e processadas destacaram-se pelo alto teor de fibra solúvel. Por outro lado, apresentaram menor teor de minerais que a goma arábica. Por meio da análise de viscosidade rápida, foi observado que este parâmetro aumentou nas amostras de goma arábica processadas, enquanto nas amostras processadas de goma de cajueiro houve redução. Nos resultados da análise de difração de raios X predominou-se a conformação amorfa das cadeias poliméricas de ambas as amostras. A partir dos parâmetros avaliados, a goma de cajueiro poderia ser indicada como substituta da goma arábica.

  5. EFEITO DA GOMA ARÁBICA NAS CONCENTRAÇÕES DE COLESTEROL HEPÁTICO, SÉRICO E FECAL DE RATOS ALIMENTADOS COM SEMENTE DE LINHAÇA, ÓLEO DE LINHAÇA E COLESTEROL SINTÉTICO

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    S. S. MELO

    2009-01-01

    Full Text Available

    A semente de linhaça, rica em ácidos graxos poliinsaturados, tem sido sugerida para reduzir o risco de doenças cardiovasculares. O presente estudo objetivou avaliar os efeitos das dietas com semente ou óleo de linhaça substituindo em até 50% os teores de óleo de soja da dieta original, associadas ou não à goma arábica (5%, nas concentrações de colesterol hepático, sérico e fecal de 66 ratos distribuídos em 11 grupos induzidos ou não à hipercolesterolemia com a adição de 1% de colesterol sintético na dieta. Durante os 28 dias de experimento os animais permaneceram em ambiente controlado, receberam suas respectivas dietas e a excreção fecal foi registrada semanalmente. Após este período foi realizada a eutanásia e coletou-se sangue e fígado para análises. Com a metodologia adotada não foi possível induzir acúmulo de colesterol hepático e sérico, com exceção quando o óleo de linhaça foi adicionado. A goma arábica quando associada ao óleo de linhaça exerceu efeito redutor sobre as concentrações hepáticas de colesterol (-68,39%, em animais induzidos à hipercolesterolemia. A semente de linhaça associada à goma arábica na presença ou não de dieta hipercolesterolemiante reduziu as concentrações séricas de colesterol em 25,56% e 24,17%, respectivamente. Desse modo, conclui-se que a adição dietética de goma arábica associada ao óleo ou à semente de linhaça pode trazer benefícios para o metabolismo lipídico.

  6. 21 CFR 582.7339 - Guar gum.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Guar gum. 582.7339 Section 582.7339 Food and Drugs..., AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Stabilizers § 582.7339 Guar gum. (a) Product. Guar gum. (b) Conditions of use. This substance is generally recognized as safe when used...

  7. EFEITO DA DESIDRATAÇÃO FOAM MAT NA RETENÇÃO DA VITAMINA C DA POLPA DE CAJAMANGA

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    Caroline Alves BREDA

    2013-04-01

    Full Text Available O objetivo do trabalho foi avaliar o efeito da desidratação foam mat na retenção da vitamina C em polpa de cajamanga. A polpa de cajamanga foi elaborada a partir de quatro formulações utilizando três agentes espumantes combinados em diferentes concentrações: 1 pectina cítrica, 2 produto à base de monoglicerídeos destilados, monoestearato de sorbitana e polissorbato 60 (Emustab e 3 produto à base de sacarose, carboximetilcelulose e goma guar (Super Liga Neutra. A composição proximal e o conteúdo de vitamina C foram determinados na polpa fresca e nas polpas desidratadas obtidas a partir das formulações. Os resultados mostraram que a adição de agentes espumantes favoreceu ao incremento de açúcares e fibras na polpa desidratada. Os agentes formadores de espuma influenciaram na retenção da vitamina C. A polpa desidratada contendo 1,5% de Emustab e 1,0% de pectina obteve maior retenção da vitamina (28,55%.

  8. Influência da adição da goma arábica em filmes isolados de polímero acrílico: estudo das propriedades de intumescimento e de permeabilidade Influence of arabic gum in acrylic polymer isolated films: study of swelling properties and permeability

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    Victor Gustavo Santos Gabas

    2003-12-01

    Full Text Available Goma arábica associada ao polímero acrílico Eudragit RS30D® na formação de filmes isolados foram obtidos e investigados como material potencialmente adequado à liberação modificada de fármacos. Foram preparadas dispersões aquosas de 4% (p/v e o citrato de trietila (20% massa polímero acrílico foi usado como plastificante. Dispersões foram vertidas em placa de Nylon revestida com Teflon® e colocadas em estufa a 60 ºC. A determinação do índice de intumescimento (Ii% em fluidos de simulação gástrica (FSG e intestinal (FSI, além da permeabilidade ao vapor d'água (TVA foram avaliadas. As dispersões propostas apresentaram habilidades filmogênicas. O polissacarídeo favoreceu, proporcionalmente à sua concentração, o grau de hidratação e a permeabilidade ao vapor d'água dos filmes formados. Estas particularidades observadas sugerem que os filmes constituídos por estas associações garantem acessibilidade com maior intensidade, quando comparado ao polimetacrilato individualmente, condição essa indispensável para uma biodegradação efetiva, em especial às regiões distais do trato gastrintestinal.Arabic gum combined with polymeric acrylic Eudragit RS30D® in isolated films for film coating, were obtained and investigated as potential material adapted for drug delivery systems. They were prepared aqueous dispersions of 4% (p/v, the triethyl citrate (20% w/w of the methacrylate polymer it was used with plasticizer. Sample of dispersions were poured over plate of Nylon covered with Teflon and placed in an air circulated oven at 60 ºC. Determination of the swelling index (Is% in fluids of gastric (SGF or intestinal simulation or intestinal (SIF, and the permeability to the water vapour (TVA were investigated. An increase in the amount of added polysaccharide favored the degree of hydration/swelling and permeability of the formed films. These observed particularities suggest that the films constituted by these

  9. Study Of Hydration Kinetics and Rheological Behaviour of Guar Gum

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    K.Nandhini Venugopal

    2010-01-01

    Full Text Available Guar galactomannan is a plant polysaccharide with extensive pplications in food, paper, textile and petroleum industries. The main advantages for using guar are its low cost, easy availability and capacity to form viscous solutions and gels at low concentration. Additionally, chain architecture of guar galactomannan can be selectively modified to tailor properties of guar formulations and open up new opportunities for guar usage.The parameters such as hydration of guar, intrinsic viscosity measurements for determining the molecular weight of guar, rheological properties of guar were studied.

  10. Under Familiar Fire: Making Decisions During the “Kivu Crisis” 2008 in Goma, DR Congo Unter vertrautem Feuer: Entscheidungsfindung während der “Kivu-Krise” in Goma, DR Kongo, 2008

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    Silke Oldenburg

    2010-01-01

    Full Text Available This paper explores the decision-making processes used by the inhabitants of Goma during the Kivu Crisis in October 2008. The paper’s aim is twofold: After providing a short history of the October 2008 events, it seeks in the empirical part to distinguish and clarify the role of rumours and narratives in the setting of violent conflict as well as to analyse their impact on decision-making processes. As the epistemological interest lies more on the people who stay rather than those who flee, in the second part the paper argues that the practice of routinization indicates a conscious tactic whose purpose is to counter the non-declared state of exception in Goma. Routinization is defined as a means of establishing order in everyday life by referring to narratives based on lived experiences. Die Autorin des Beitrags untersucht Entscheidungsfindungsprozesse der Einwohner von Goma während der Kivu-Krise im Oktober 2008. Nach einer kurzen Geschichte der Ereignisse wird im empirischen Teil des Beitrags die Rolle von Gerüchten und Erzählungen für die gesellschaftliche Szenerie gewaltsamer Konflikte aufgezeigt und voneinander abgegrenzt und ihre jeweilige Bedeutung für Entscheidungsfindungsprozesse analysiert. Da sich das Forschungsinteresse der Autorin in erster Linie auf den Teil der Bevölkerung richtet, der am Ort des Geschehens bleibt, und weniger auf den, der sich zur Flucht entscheidet, wird im zweiten Teil des Beitrags die Praxis der Routinisierung hervorgehoben, eine bewusste Strategie der Betroffenen, um mit dem nicht-deklarierten Ausnahmezustand in Goma umzugehen. Routinisierung wird als Mittel definiert, die alltägliche Ordnung aufrechtzuerhalten, indem man auf Erzählungen gelebter Erfahrung zurückgreift.

  11. Curdlan: an important microbial hydrocolloid/ Goma curdlana: um importante hidrocolóide microbiano

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    Elaine Soares Amorim

    2003-05-01

    Full Text Available The use of gums in the food industry is mainly based in its functional properties, which are related to the capacity to prevent or delay a series of physicals phenomenon, having an important role in the stability of many industrialized food. The use of these in the several food productions is indispensable, because they contribute to thickening, gelling, stabilization, suspension, film formation and gums can act as auxiliary agents of processing. Therefore, our objective was evaluated the chemistries physical properties, as well as, the areas of application of the microbial hydrocolloid, curdlan.O uso das gomas na indústria de alimentos baseia-se principalmente no aproveitamento de suas propriedades funcionais, que estão relacionadas à capacidade de prevenir ou retardar uma série de fenômenos físicos, desempenhando papel importante na estabilidade de muitos alimentos industrializados. É indispensável o uso destas na produção de diversos produtos alimentícios, pois contribuem para o espessamento, gelificação, estabilização, suspensão, formação de filme e podem atuar como agentes auxiliares de processamento. Desta forma, o presente trabalho buscou avaliar as propriedades físico-químicas, bem como, as áreas de aplicação da goma curdlana que é um hidrocolóide de origem microbiana.

  12. Modification of hydroxypropyl guar gum with ethanolamine.

    Science.gov (United States)

    Zhao, Yongchao; He, Jianping; Han, Xiaoxiao; Tian, Xiulin; Deng, Mingyu; Chen, Weiping; Jiang, Bo

    2012-10-01

    A new guar gum derivative containing amino group was synthesized through nucleophilic substitution of p-toluenesulfonate activated hydroxypropyl guar gum with ethanolamine. For the preparation of p-toluenesulfonate esters hydroxypropyl guar gum, the results showed that the reaction rate was optimal at 25 °C and the reaction could reach equilibrium state when it was carried out for 10h at 25 °C. For the nucleophilic substitution of tosyl group with ethanolamine, the reaction was completed after 10h reaction at 50 °C. The structures of products were characterized by NMR and FT-IR spectroscopy. The results showed that the p-toluenesulfonate esters can be effectively substituted by ethanolamine to form the hydroxyethyl amino hydroxypropyl guar gum (EAHPG). The content of nitrogen of EAHPG was determined by acid-base titration and element analysis.

  13. Foaming properties of guar foaming albumin

    OpenAIRE

    細見, 典子; Hosomi, Noriko; 原田, 麻子; Harada, Asako; 下山, 亜美; Shimoyama, Ami; 土居, 幸雄; Doi, Yukio

    2009-01-01

    From guar meal we recently isolated an albumin fraction with a high foaming ability, named guar foaming albumin (GFA) . Here, we further characterized the foaming activity, foam stability and surface tension of GFA solutions. Foaming activity and foam stability were estimated by measuring the conductivity of foam using a glass column with a conductivity cell. Surface tension was measured by the drop weight method using a stalagmometer. GFA showed higher foaming activity than casein at any pro...

  14. GUAR GUM: PRESENT STATUS AND APPLICATIONS

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    Surendra Tripathy

    2013-08-01

    Full Text Available Naturally occurring excipients are currently getting prime importance among which the polysaccharides occupy a special position because of their easy availability, non-toxic, eco-friendly and biodegradable nature. The objective of this review was to explore the excipient profile of Guar gum which is obtained from Cyamopsis tetragonolobus (Linn. Leguminosae. The chief constituent of guar gum is a Gallactomannan which is composed of galactose and mannose in a ratio of 1:2 that provides the main physical phenomenon of gelling or thickening to this gum. The chemistry of this gallactomannan suggested the presence of multiple hydroxyl groups which are proved to be excellent for derivatization by grafting or cross-linking with other polymers to create new chemically modified entity of desired properties. The native as well as guar gum derivatives are found to have therapeutic importance in certain physiological disorders. Guar gum is used as suspending, emulsifying and stabilizing agent in the conventional dosage forms. In tablet dosage form it is used as a potential binding and disintegrating agent. The swelling property of guar gum is used for controlling the drug release rate in the novel pharmaceutical dosage forms. By virtue of its better thickening and stabilizing power accompanied by a sound safety profile, guar gum has acquired a wide acceptance in cosmetics and food industry.

  15. Colon targeted curcumin delivery using guar gum.

    Science.gov (United States)

    Elias, Edwin J; Anil, Singhal; Ahmad, Showkat; Daud, Anwar

    2010-06-01

    Curcumin is used in the treatment of colon cancer, but its very poor absorption in the upper part of the GIT is a major concern. As a site for drug delivery, the colon offers a near neutral pH, reduced digestive enzymatic activity, a long transit time and an increased responsiveness to absorption enhancers. The aim of the present study was to identify a suitable polymer (guar gum) based matrix tablet for curcumin with sufficient mechanical strength and promising in vitro mouth-to-colon release profile. Three formulations of curcumin were prepared using varying concentrations of guar gum containing 50 mg curcumin by the wet granulation method. Tablets were subjected to evaluation by studying parameter like hardness, friability, drug content uniformity, and in-vitro drug release. In vitro drug release was evaluated using simulated stomach, intestinal and colonic fluids. The susceptibility of guar gum to colonic bacteria was also assessed by a drug release study with rat caecal contents. The 40% guar gum containing formulation (F-1) showed better drug release (91.1%) after 24 hours in the presence of rat caecal contents in comparison with the 50% guar gum containing formulation (F-2) (82.1%). Curcumin could, thus, be positively delivered to the colon for effective colon cancer treatment using guar gum.

  16. Efeito da adição de polpa, carboximetilcelulose e goma arábica nas características sensoriais e aceitação de preparados em pó para refresco sabor laranja Effect of adding pulp, carboxymethyl cellulose and arabic gum to sensory characteristics and acceptance of powdered orange-flavored refreshments

    Directory of Open Access Journals (Sweden)

    Valentina de Fátima Caleguer

    2007-06-01

    Full Text Available O trabalho teve como objetivo avaliar o efeito sensorial da adição de polpa, carboximetilcelulose (CMC e goma arábica (fibra nos atributos e aceitação de refrescos de laranja. Utilizou-se uma amostra padrão e outras formuladas com polpa, CMC, fibra e todos os ingredientes. Foram realizadas análises físico-químicas (pH, acidez titulável, sólidos solúveis, vitamina C, cor e turbidez, e as amostras também foram caracterizadas pela técnica de Perfil Livre. Na análise descritiva utilizou-se 14 provadores e, para a avaliação dos resultados foi empregada a Análise Procrustes Generalizada. As amostras caracterizadas como diferentes (padrão, CMC, fibra foram submetidas a teste de aceitação. Os refrescos foram caracterizados e separados com base em atributos de aparência (cor laranja e turbidez, aroma (adocicado e laranja, sabor (doce, laranja e ácido e textura (viscosidade. O padrão e a amostra com polpa, que não foram diferenciadas sensorialmente, apresentaram menor intensidade de cor laranja e turbidez, e foram consideradas menos encorpadas e mais ácidas. As amostras com CMC e fibra se diferenciaram do padrão e apresentaram comportamento intermediário. A formulação com todos os ingredientes apresentou características opostas: maior intensidade de cor e turbidez, mais encorpada e menos ácida. As amostras com CMC e fibra foram mais aceitas que o padrão.The aim of this work was to evaluate the sensory effect of adding pulp, carboxymethyl cellulose (CMC and arabic gum (fiber to characteristics and acceptance of powdered orange flavored soft drinks. A standard sample and another formulated with pulp, CMC, fiber with all the ingredients were used. Physicochemical analyses (pH, titratable acidity, soluble solids, vitamin C, color and turbidity were applied and samples were characterized by Free-Choice Profiling. Fourteen panelists were used in the descriptive analysis and the Generalized Procrustes Analysis was applied to

  17. Biobased alternatives to guar gum as tackifiers for hydromulch

    Science.gov (United States)

    Guar gum, obtained from guar [Cyamopsis tetragonoloba (L.) Taub.] seeds, is currently the principal gum used as a tackifier (binder) for hydraulically-applied mulches (hydromulches) used in erosion control. The oil industry’s increased use of guar gum in hydraulic fracturing together with lower glo...

  18. Synthesis and characterization of guar gum templated hybrid nano silica.

    Science.gov (United States)

    Singh, V; Singh, S K; Pandey, S; Sanghi, R

    2011-08-01

    The objective of the present study was the fabrication of green adsorbent hybrids for which native guar gum was used as template to polymerize tetraethoxysilane. The properties and performances of the hybrids could be tailored by using varying molecular sizes of the partially depolymerized guar gum templates of various molecular sizes as control. Zn(II) uptake from aqueous solution was used as a criterion for evaluating the adsorbent efficiency. The optimum material (H4) in terms of maximum Zn(II) uptake, was obtained when the template size used was 375 kDa at a calcination temperature of 700°C. H4 was also evaluated for Ca(II), Mg(II), Cd(II) and Hg(II) adsorption. To explore the other applicability areas, the hybrids have been extensively characterized using FTIR, XRD, TGA-DTA, PL, SEM, TEM and BET analyses. H4 was found to be as efficient as previously reported vinyl modified-silica nanohybrids. It had a high surface area (264 m(2)/g) with silica nanoparticles in the size range of 90-140 nm. Being thermally very stable and photoluminescent, the material can be potentially used for many biological, medical and environmental applications.

  19. Linear Rheology of Guar Gum Solutions

    NARCIS (Netherlands)

    Wientjes, Roland H.W.; Duits, Michel H.G.; Jongschaap, Rob J.J.; Mellema, Jorrit

    2000-01-01

    We have investigated the linear viscoelastic behavior of guar gum solutions as a function of frequency, temperature, polymer concentration, and molecular weight. This was done to sort out the importance of different relaxation mechanisms like reptation or the breakup of physical bonds. In the kilohe

  20. GOMA: functional enrichment analysis tool based on GO modules

    Institute of Scientific and Technical Information of China (English)

    Qiang Huang; Ling-Yun Wu; Yong Wang; Xiang-Sun Zhang

    2013-01-01

    Analyzing the function of gene sets is a critical step in interpreting the results of high-throughput experiments in systems biology.A variety of enrichment analysis tools have been developed in recent years,but most output a long list of significantly enriched terms that are often redundant,making it difficult to extract the most meaningful functions.In this paper,we present GOMA,a novel enrichment analysis method based on the new concept of enriched functional Gene Ontology (GO) modules.With this method,we systematically revealed functional GO modules,i.e.,groups of functionally similar GO terms,via an optimization model and then ranked them by enrichment scores.Our new method simplifies enrichment analysis results by reducing redundancy,thereby preventing inconsistent enrichment results among functionally similar terms and providing more biologically meaningful results.

  1. GOMA: functional enrichment analysis tool based on GO modules

    Science.gov (United States)

    Huang, Qiang; Wu, Ling-Yun; Wang, Yong; Zhang, Xiang-Sun

    2013-01-01

    Analyzing the function of gene sets is a critical step in interpreting the results of high-throughput experiments in systems biology. A variety of enrichment analysis tools have been developed in recent years, but most output a long list of significantly enriched terms that are often redundant, making it difficult to extract the most meaningful functions. In this paper, we present GOMA, a novel enrichment analysis method based on the new concept of enriched functional Gene Ontology (GO) modules. With this method, we systematically revealed functional GO modules, i.e., groups of functionally similar GO terms, via an optimization model and then ranked them by enrichment scores. Our new method simplifies enrichment analysis results by reducing redundancy, thereby preventing inconsistent enrichment results among functionally similar terms and providing more biologically meaningful results. PMID:23237213

  2. Guar gum: processing, properties and food applications-A Review.

    Science.gov (United States)

    Mudgil, Deepak; Barak, Sheweta; Khatkar, Bhupendar Singh

    2014-03-01

    Guar gum is a novel agrochemical processed from endosperm of cluster bean. It is largely used in the form of guar gum powder as an additive in food, pharmaceuticals, paper, textile, explosive, oil well drilling and cosmetics industry. Industrial applications of guar gum are possible because of its ability to form hydrogen bonding with water molecule. Thus, it is chiefly used as thickener and stabilizer. It is also beneficial in the control of many health problems like diabetes, bowel movements, heart disease and colon cancer. This article focuses on production, processing, composition, properties, food applications and health benefits of guar gum.

  3. Diseño de una planta de producción de goma Xantana a partir de melaza de remolacha

    OpenAIRE

    2015-01-01

    Objeto del proyecto El objetivo del presente proyecto es el diseño de una planta de producción de goma xantana a partir de melaza de remolacha, así como la descripción y dimensionamiento de las principales unidades de proceso de la planta industrial. Justificación La elección del presente Proyecto Fin de Carrera se sustenta en la posibilidad de obtener un producto que muestra propiedades muy interesantes en cuanto a su reología y textura. El motivo principal para su desarrollo, es da...

  4. Purified guar galactomannan as an improved pharmaceutical excipient.

    Science.gov (United States)

    Gebert, M S; Friend, D R

    1998-08-01

    The purpose of this study was to assess certain pharmaceutical attributes of guar galactomannan, a hydrocolloid polysaccharide obtained from the endosperm of the leguminous plant Cyamopsis tetragonolobus (L.), following purification using both literature procedures and new processes. Experiments were performed to measure viscosity, hydration rate, tablet hardness, and dissolution profiles of guar galactomannan both before and after purification. The viscosity of an aqueous 1% purified galactomannan solution is typically 40-50% higher than its unpurified guar galactomannan precursor. The hydration rate of an aqueous 1% purified galactomannan solution increases by 100% after purification. These physicochemical changes resulted in improvements in pharmaceutical properties such as better stir speed independence in both tablet and capsule dissolution profiles and improved tablet hardness. For instance, time to 50% dissolution of ranitidine HCl from capsules containing unpurified guar gum was 0.4 and 1.8 hr at 20 and 40 rpm, respectively, using USP Apparatus II. Using the same amount of purified guar gum and the same conditions (20 and 40 rpm), these values were increased to 2.9 and 3.8 hr, respectively. These data demonstrate a reduced effect of changing agitation conditions and the need for less guar gum to sustain the release of a water-soluble drug. Tablet hardness of purified guar gum (particle size < 75 microns) was about 7 kP and the same unpurified guar gum of equal particle size and hydration gave a hardness of less than 1 kP.

  5. INTERMOLECULAR AND INTRAMOLECULAR INTERACTIONS OF POLYMER GUAR GUM IN SOLUTIONS

    Institute of Scientific and Technical Information of China (English)

    Yun-fei Yan; Hai-yang Yang; Wen-yong Liu; Ping-ping Zhu; Ping-sheng He

    2005-01-01

    The tetrahedral borate ion can crosslink with polymer guar gum in aqueous solutions. If the concentration of guar gum is less than 0.045 g/dL, the intramolecular interaction between guar gum and borate ion increases due to the formation of crosslinks. As a result, the polymer chains of guar gum in solution shrink in size and the reduced viscosity of polymer solution decreases accordingly. On the other hand, if the concentration of guar gum is greater than 0.045 g/dL, the intermolecular interaction becomes apparent due to the same reason. The polymer chains, therefore, associate together and the reduced viscosity of polymer solution increases considerably. According to this technique, the critical concentration c*,presented by de-Gennes[1], is determined successfully.

  6. Análises físico-químicas e estabilidade de compostos bioativos presentes em polpa de uvaia em pó obtidos por métodos de secagem e adição de maltodextrina e goma arábica

    Directory of Open Access Journals (Sweden)

    Fernanda Krumreich

    2016-09-01

    Full Text Available A uvaia apresenta curta vida pós-colheita e a obtenção de frutas em pó adicionadas de gomas visam aumentar a sua estabilidade. Portanto, estudou-se a influência do método de desidratação e da aplicação de gomas (maltodextrina e goma arábica sobre a estabilidade dos compostos da polpa de uvaia em pó, avaliando-se: higroscopicidade, solubilidade, cor, retenção de carotenoides, ácido ascórbico e parâmetros físico-químicos. A liofilização preservou a cor amarela intensa da polpa, bem como, o ácido ascórbico. A adição das gomas foram eficientes em aumentar a solubilidade dos pós obtidos tanto por liofilização quanto por secagem em estufa a 70ºC e diminuir a higroscopicidade destes últimos, enquanto os pós sem tratamento apresentaram a menor solubilidade.

  7. Synthesis of galactosyl glycerol from guar gum by transglycosylation of α-galactosidase from Aspergillus sp. MK14.

    Science.gov (United States)

    Kurakake, Masahiro; Okumura, Takumi; Morimoto, Youichirou

    2015-04-01

    A guar gum-hydrolyzing strain, Aspergillus sp. MK14, secreted α-galactosidase selectively in liquid culture. Its α-galactosidase activity (0.820 U/ml) was much higher than its β-mannosidase and β-mannanase activities (0.027 and 0.050 U/ml, respectively). The molecular weight was estimated to be 59,000 Da by SDS-PAGE. The optimal pH was 5 and it was active from pH 2.2 to 6.2. The optimal temperature was 60 °C and the activity was stable below 50 °C. Enzyme activity toward melibiose was much lower than that with pNP-α-D-galactopyranoside. The activities toward 6(1)-α-D-galactosyl-mannobiose and 6(3),6(4)-α-D-galactosyl-mannopentaose were relatively high (86.2% and 48.4% relative to pNP-α-D-galactopyranoside, respectively). MK14 crude enzyme released only the monosaccharides, galactose and mannose (Gal/Man: 0.64) from guar gum. When glycerol was added to the reaction mixture, the transglycosylation proceeded efficiently, and the synthesis of galactosyl glycerol was 76.6 mg/g of guar gum. MK14 α-galactosidase could use guar gum as a good substrate (donor) in the transglycosylation.

  8. Physico-chemical interactions between corn starches and hydrocolloids (guar and xantham gums) and their effects on the functional properties.

    OpenAIRE

    2005-01-01

    Resumo: O amido é utilizado como agente gelificante na indústria de alimentos. Devido a diversidade de textura que pode ser obtida com o amido, ele é usado para produtos que vão desde sopas líquidas até pudins com consistência sólida, mas é nos produtos de panificação que adquire maior importância, por ser um componente presente naturalmente nas farinhas de cereais. A incorporação de gomas em suspensões de amido modifica as propriedades reológicas, causa aumento da viscosidade, melhora a text...

  9. Propiedades fisicoquímicas y funcionales de las gomas de acacia cochliacantha y acacia farnesiana.

    OpenAIRE

    Sibaja Hernández, Roberto

    2016-01-01

    Acacia cochliacantha y Acacia farnesiana son recursos bióticos poco estudiados que presentan gomosis. El presente trabajo aporta conocimiento de las características fisicoquímicas, comportamiento reológico y capacidad de emulsión de las gomas de árboles de A. cochliacantha y A. farnesiana colectadas en la selva baja caducifolia de Morelos, México. Las gomas de Prosopis laevigata y Acacia senegal se usaron como referentes. Las plantas de A. cochliacantha crecen en suelos del tipo Leptosol rend...

  10. The effect of ingestion of guar gum on ileostomy effluent.

    Science.gov (United States)

    Higham, S E; Read, N W

    1992-01-01

    Randomized, paired studies were carried out on five healthy volunteers equipped with terminal ileostomies to investigate the effect of incorporating 15 g of the viscous polysaccharide guar gum in the normal diet on the volume, weight, composition and physical properties of ileostomy effluent. Subjects ate an identical diet during two 5 d study periods, which were separated by 2 d. Outputs of fat, protein, sodium, potassium, dry weight and water were all increased during guar gum administration, but outputs of carbohydrate, calcium and phosphorus were not significantly altered. Mouth-to-stoma transit was not significantly affected and, surprisingly, the viscosity of the ileostomy effluent was reduced by guar gum. These results show that it is not always possible to predict what will happen to small intestinal function when guar gum is added to the diet from experiments carried out when guar gum is administered alone or with glucose. While our findings show that guar gum will reduce fat absorption, the mechanisms involved are more sophisticated than hitherto envisaged.

  11. Cholera epidemic among Rwandan refugees: experience of ICDDR,B in Goma, Zaire.

    Science.gov (United States)

    Siddique, A K

    1994-01-01

    In July 1994, one of the worst cholera epidemics broke out among the nearly a million Rwandan refugees in Goma, eastern Zaire. The United Nations High Commission for Refugees estimated that nearly 12,000 people died during the epidemic. The International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B) sent an eight-member medical team to Goma headed by Dr AK Siddique, a senior scientist of the Center and head of the Epidemic Control Preparedness Program, Dacca, Bangladesh. During their two-week stay, the team, in collaboration with UNICEF and the Ministry of Health, Zaire, conducted epidemiological assessment, operated a temporary treatment center and provided technical advice on case management of cholera and shigellosis to other health workers. The team also set up a microbiology laboratory in Goma to identify the pathogens responsible for the epidemic and their drug sensitivity patterns. The team visited a number of temporary treatment facilities in two of the five camp sites and provided technical advice to the health-care providers. They also visited treatment facilities in Goma city, where an estimated 200,000 refugees were affected by the epidemic. Deaths from cholera even in the treatment centers were much higher than expected. The overall case-fatality rate in the treatment centers was nearly 15%. Laboratory investigations showed that the initial epidemic was indeed caused by Vibrio cholerae strains resistant to tetracycline and doxycycline. By the first week of August, the number of cholera cases was declining, but the number of dysentery cases was increasing rapidly. Predominantly Shigella dysenteriae type 1 was responsible, which was resistant to most drugs used for treating shigellosis, except mecillinam. Inappropriate rehydration therapy and inadequate experience of health workers failed to prevent deaths. The team took over the operation of temporary treatment center at Katindo in Goma city with one of the highest case-fatality rates (14

  12. Ultrasound assisted enzymatic depolymerization of aqueous guar gum solution.

    Science.gov (United States)

    Prajapat, Amrutlal L; Subhedar, Preeti B; Gogate, Parag R

    2016-03-01

    The present work investigates the effectiveness of application of low intensity ultrasonic irradiation for the intensification of enzymatic depolymerization of aqueous guar gum solution. The extent of depolymerization of guar gum has been analyzed in terms of intrinsic viscosity reduction. The effect of ultrasonic irradiation on the kinetic and thermodynamic parameters related to the enzyme activity as well as the intrinsic viscosity reduction of guar gum using enzymatic approach has been evaluated. The kinetic rate constant has been found to increase with an increase in the temperature and cellulase loading. It has been observed that application of ultrasound not only enhances the extent of depolymerization but also reduces the time of depolymerization as compared to conventional enzymatic degradation technique. In the presence of cellulase enzyme, the maximum extent of depolymerization of guar gum has been observed at 60 W of ultrasonic rated power and ultrasonic treatment time of 30 min. The effect of ultrasound on the kinetic and thermodynamic parameters as well as the molecular structure of cellulase enzyme was evaluated with the help of the chemical reaction kinetics model and fluorescence spectroscopy. Application of ultrasound resulted in a reduction in the thermodynamic parameters of activation energy (Ea), enthalpy (ΔH), entropy (ΔS) and free energy (ΔG) by 47%, 50%, 65% and 1.97%, respectively. The changes in the chemical structure of guar gum treated using ultrasound assisted enzymatic approach in comparison to the native guar gum were also characterized by FTIR. The results revealed that enzymatic depolymerization of guar gum resulted in a polysaccharide with low degree of polymerization, viscosity and consistency index without any change in the core chemical structure which could make it useful for incorporation in food products.

  13. Analysis of proteins associated with growth of Bacteroides ovatus on the branched galactomannan guar gum.

    OpenAIRE

    Valentine, P J; Salyers, A A

    1992-01-01

    Bacteroides ovatus, a gram-negative obligate anaerobe from the human colon, can ferment the branched galactomannan guar gum. Previously, three enzymes involved in guar gum breakdown were characterized. The expression of these enzymes appeared to be regulated; i.e., specific activities were higher in extracts from bacteria grown on guar gum than in extracts from bacteria grown on the monosaccharide constituents of guar gum, mannose and galactose. In the present study, we used two-dimensional g...

  14. Propiedades Fisicoquímica, Reológica y funcionalidad de la goma de semilla de Prosopis juliflora "cuji"

    OpenAIRE

    Rincón Acosta, Fernando Javier

    2013-01-01

    Las gomas, hidrocoloides, son ampliamente usadas en la industria alimentaria, donde cumplen diferentes aplicaciones, tales como productos del control de la humedad, espesantes, agentes gelificantes, estabilizadores de diferentes tipos de dispersiones, fibras dietarías, inhibidores de la cristalización e incluso como emulsionantes. Considerando que las gomas exhiben interesantes propiedades como estabilizantes y emulsionantes, es importante su caracterización reológica (compo...

  15. Propriedades de barreira e solubilidade de filmes de amido de ervilha associado com goma xantana e glicerol Barrier properties of films of pea starch associated with xanthan gum and glycerol

    Directory of Open Access Journals (Sweden)

    Manoel D. da Matta Jr

    2011-01-01

    Full Text Available O objetivo do trabalho foi avaliar as propriedades de barreira e a solubilidade de biofilmes obtidos a partir de amido de ervilha de alto teor de amilose em associação à goma xantana e glicerol. Soluções filmogênicas (SF com diferentes teores de amido de ervilha (3, 4 e 5%, goma xantana (0, 0,05 e 0,1% e glicerol (proporção glicerol-amido de 1:5 P/P foram estudadas. As SF foram obtidas por ebulição (5 minutos, seguida de autoclavagem por 1 hora a 120 ºC e os filmes foram preparados por casting. O aumento da concentração de amido e de glicerol na composição causou aumento da espessura e da solubilidade dos filmes em água. O plastificante gerou ainda elevação dos coeficientes de permeabilidade ao vapor d'água e ao oxigênio. O aumento da concentração da goma xantana não interferiu nas propriedades estudadas. Os biofilmes obtidos a partir de amido de ervilha verde, associado ou não à goma xantana e glicerol, se comparados com filmes de amido de ervilha amarelas e outras fontes de amido, apresentaram boa barreira ao oxigênio e ao vapor d'água e baixa solubilidade em água.The aim of this work was to evaluate the barrier properties and solubility of biofilms made from wrinkled pea starch with high amylose content in association with xanthan gum and glycerol. Filmogenic solution (FS with different levels of pea starch (3, 4 and 5%, xanthan gum (0, 0.05 and 0.1% and glycerol (glycerol-starch 1:5 W/W were tested. FS was obtained by boiling (5 minutes, autoclaving for 1 hour at 120 ºC and the films were prepared by casting. The increased concentration of starch and glycerol in the composition caused increases in thickness of the films and in their solubility in water. The plasticizer also generated higher coefficients of water vapor and oxygen permeabilities to water vapor and to oxygen. The increasing concentration of xanthan gum did not interfere in the properties studied. Biofilms produced with wrinkled pea starch, with or

  16. TECHNICAL NOTE: The effect of the green additive guar gum on the properties of magnetorheological fluid

    Science.gov (United States)

    Fang, Chen; Zhao, Bin Yuan; Chen, LeSheng; Wu, Qing; Liu, Nan; Hu, Ke Ao

    2005-02-01

    Magnetorheological (MR) fluid containing guar gum was prepared for the first time by ball-milling the guar gum powder together with silicone oil and carbonyl iron powder. By forming a coating layer over the ground carbonyl iron powder, the guar gum improves the sedimentation stability and thixotropy of the MR fluid effectively.

  17. Synthesis of Hydroxypropyl Guar Gum by Phase Transfer Catalysis

    Institute of Scientific and Technical Information of China (English)

    Rong Chun XIONG; Ming Zhu CHANG; Jian Ming CHEN; Nan ZHOU; Gang WEI

    2005-01-01

    HGG (Hydroxypropyl guar gum) was synthesized by phase transfer catalysis for the first time. The effects of alkalinity, phase transfer catalyst, etherification, pH value, temperature,reaction time and stirring speed were investigated. An optimal synthetic reaction technology was established, namely, dose of guar gum is 100 g, propylene oxide 40-50 g, HTAC (hexadecyl trimethyl ammonium chloride ) 1.3-1.7 g, pH value 10-10.5, temperature 45-50℃, and reaction time 3-4 hours. The result shows that the improved HGG has high viscosity. Its dissolution speed, content of insoluble residue, colloid light transparency and stability are apparently superior to guar flour.

  18. Post-electrospinning crosslinking of guar/polyvinyl alcohol membrane

    Directory of Open Access Journals (Sweden)

    Shi Jingjing

    2016-01-01

    Full Text Available College of Material and Textile Engineering, Jiaxing University, Jiaxing, China The present study reports post-electrospinning crosslinking of guar/polyvinyl alcohol (PVA/citric acid nanofiber membranes by heat treatment. Porous, interconnected nonwoven nanofiber membranes (average diameter 194±23 nm were electrospun from a homogeneous blend of 1wt% guar gum and 8wt% polyvinyl alcohol solution (3:7 weight ratio containing 5 wt% (by the total weight of the solution citric acid. The electrospun nanofiber membranes were then cured at 140 oC for 2 h. The crosslinked nanofiber membranes were insoluble in water, while the non-crosslinked membranes dissolved instantaneously. FT-IR spectrum investigates that crosslinking of guar/PVA occurred through esterfication reaction during heat treatment.

  19. CARACTERIZACIÓN BIOQUÍMICA Y PROPIEDADES VISCOELÁSTICAS DE GOMAS DE Acacia farnesiana (L.) Willd. y Acacia cochliacantha Humb. & Bonpl. ex Willd.

    OpenAIRE

    Cabañas García, Emmanuel

    2014-01-01

    Las gomas son biopolímeros formados principalmente por carbohidratos y en una menor proporción por proteínas. Las proteínas de algunas gomas son del tipo arabinogalactano-proteínas (AGPs). Las características bioquímicas de éstos compuestos son las que definen las propiedades funcionales de las gomas. El objetivo de este trabajo fue conocer algunas de las características bioquímicas y propiedades viscoelásticas de las gomas de Acacia farnesiana y Acacia cochliacantha, dos especies característ...

  20. Preparation and characterization of carboxymethyl guar gum nanoparticles.

    Science.gov (United States)

    Gupta, Anek Pal; Verma, Devendra Kumar

    2014-07-01

    Carboxymethyl guar gum nanoparticles (CMGGNPs) were synthesized by nanoprecipitation and sonication method. This method was used for the first time for the synthesis of carboxymethyl guar gum nanoparticles. It was found that the formation of nanoparticles might depend upon the sonication time, solvent, and stirring time. Nanoparticles were characterized by SEM, TEM, XRD and FTIR. The sizes of the particles in suspension have been found in the range 12-30nm. It was concluded that such type of nanoparticles may be used in pharmaceutical and drug delivery.

  1. Effect of enzymatic depolymerization on physicochemical and rheological properties of guar gum.

    Science.gov (United States)

    Mudgil, Deepak; Barak, Sheweta; Khatkar, B S

    2012-09-01

    Depolymerization of guar gum using enzymatic hydrolysis was performed to obtain depolymerized guar gum having functional application as soluble dietary fiber. Enzymatic hydrolysis of guar gum significantly affected the physicochemical and rheological characteristics of guar gum. The depolymerized guar gum showed a significant increase in crystallinity index from 3.86% to 13.2% and flow behavior index from 0.31 to 1.7 as compared to native guar gum. Remarkable decrease in intrinsic viscosity and consistency index was also observed from 9 to 0.28 and 4.04 to 0.07, respectively. Results revealed that enzymatic hydrolysis of guar gum resulted in a polysaccharide with low degree of polymerization, viscosity and consistency which could make it useful for incorporation in food products as dietary fiber without affecting the rheology, consistency and texture of the products.

  2. Desenvolvimento de espessante alimentar com valor nutricional agregado, destinado ao manejo da disfagia

    Directory of Open Access Journals (Sweden)

    Carlos Henrique Pagno

    2014-04-01

    Full Text Available A disfagia se caracteriza por uma disfunção no processo de deglutição, sinal prevalente de doenças degenerativas como esclerose múltipla e doença de Parkinson. Alimentos de textura modificada e bebidas espessadas são tradicionalmente utilizados no auxílio para o tratamento clínico da disfagia. Assim, este trabalho objetivou desenvolver uma formulação de espessante alimentar com valor nutricional agregado, e avaliar sua eficiência em diferentes alimentos líquidos (leite integral, sucos de maçã, uva e laranja, sob diferentes condições de tempo de preparo (10 e 120 minutos e 24 horas e temperatura ambiente (25°C e refrigerada (10°C. A formulação foi composta de concentrado proteico de soro, mix de vitaminas e minerais e goma guar como agente espessante. Os valores obtidos para a viscosidade mostraram diferença estatisticamente significativa (P<0,05 entre os tempos de espessamento, sendo que as viscosidades no tempo de 10 minutos e após 24 horas variaram, respectivamente, 58±3cP a 180±2cP na consistência de néctar; de 310±4Cp a 1084±3cP na consistência de mel e 844±14 a 2848±22cP na consistência de pudim. No entanto, a maioria das bebidas permaneceu dentro dos padrões internacionais sugeridos pela National Dysphagia Diet (NDD, para a consistência de alimentos destinados a pacientes disfágicos.

  3. New Guar Biopolymer Silver Nanocomposites for Wound Healing Applications

    Directory of Open Access Journals (Sweden)

    Runa Ghosh Auddy

    2013-01-01

    Full Text Available Wound healing is an innate physiological response that helps restore cellular and anatomic continuity of a tissue. Selective biodegradable and biocompatible polymer materials have provided useful scaffolds for wound healing and assisted cellular messaging. In the present study, guar gum, a polymeric galactomannan, was intrinsically modified to a new cationic biopolymer guar gum alkylamine (GGAA for wound healing applications. Biologically synthesized silver nanoparticles (Agnp were further impregnated in GGAA for extended evaluations in punch wound models in rodents. SEM studies showed silver nanoparticles well dispersed in the new guar matrix with a particle size of ~18 nm. In wound healing experiments, faster healing and improved cosmetic appearance were observed in the new nanobiomaterial treated group compared to commercially available silver alginate cream. The total protein, DNA, and hydroxyproline contents of the wound tissues were also significantly higher in the treated group as compared with the silver alginate cream (P<0.05. Silver nanoparticles exerted positive effects because of their antimicrobial properties. The nanobiomaterial was observed to promote wound closure by inducing proliferation and migration of the keratinocytes at the wound site. The derivatized guar gum matrix additionally provided a hydrated surface necessary for cell proliferation.

  4. Influence of deacetylation on the rheological properties of xanthan-guar interactions in dilute aqueous solutions.

    Science.gov (United States)

    Khouryieh, H A; Herald, T J; Aramouni, F; Bean, S; Alavi, S

    2007-04-01

    An oscillating capillary rheometer was used to investigate the effects of xanthan deacetylation on the viscoelastic properties and intrinsic viscosity of xanthan and guar mixtures in dilute aqueous solutions. Deacetylated xanthan exhibited a stronger synergistic interaction with guar than native xanthan did due to the destabilized helical structure and increased chain flexibility of the deacetylated xanthan. No gels were observed for all xanthan-guar mixtures. Native xanthan-guar mixtures exhibited a liquid-like behavior, whereas deacetylated xanthan-guar mixtures exhibited a gel-like behavior. The relative viscosity and elasticity of deacetylated xanthan-guar mixtures were much stronger than those for native xanthan-guar mixtures. The intrinsic viscosities of deacetylated xanthan-guar mixtures were higher than the calculated values assuming no interaction, whereas the intrinsic viscosities of native xanthan-guar mixtures were lower than the calculated values assuming no interaction, demonstrating that intermolecular binding occurred between the disordered segments of xanthan and guar gum in dilute aqueous solutions.

  5. Dynamic and shear stress rheological properties of guar galactomannans and its hydrolyzed derivatives.

    Science.gov (United States)

    Hussain, Majid; Bakalis, Serafim; Gouseti, Ourania; Zahoor, Tahir; Anjum, Faqir Muhammad; Shahid, Muhammad

    2015-01-01

    Guar galactomannan from seed of Cyamopsis tetragonolobus was hydrolyzed using acid (HCl), base [Ba(OH)2] and enzyme (mannanase) method to obtain depolymerized substances with possible functional applications as soluble dietary fiber. Rheological behavior of crude, purified, and depolymerized guar gum solutions was studied at 25 °C, using shear stress and dynamic oscillatory measurements, performed with controlled stress rheometer Bohlin CVO (Malvern Instruments) fitted with cone-and-plate geometry. The various guar gums solutions with different viscosities exhibited shear-thinning behavior at high shear rate and Newtonian behavior at low shear rate. At low shear rate, sigma crude guar gum (SCGG), crude guar gum (CGG), acid hydrolyzed guar gum (AHGG) and enzyme hydrolyzed guar gum (EHGG) exhibited viscosities of 18.59, 1.346, 0.149 and 0.022 Pas, respectively. Oscillatory experiments (G", G') of gums solutions showed typical behavior of weak viscoelastic gel. All investigated guar gums were further used for glucose bio-accessibility using a novel in vitro small intestinal model (SIM). All gums solutions resulted in 20% reduction in simulated glucose absorption, indicating a non-significant functionality difference between various guar gums. So, it can be concluded that hydrolyzed guar gums without disturbing their rheological and physiological behavior would be useful for incorporation in various food products as soluble dietary fiber.

  6. Evaluation of guar gum derivatives as gelling agents for microbial culture media.

    Science.gov (United States)

    Gangotri, Waikhom; Jain-Raina, Ruchi; Babbar, Shashi B

    2012-05-01

    Guar gum, a galactomannan, has been reported to be an inexpensive substitute of agar for microbial culture media. However, its use is restricted probably because of (1) its highly viscous nature even at high temperatures, making dispensing of the media to Petri plates difficult and (2) lesser clarity of the guar gum gelled media than agar media due to impurities present in guar gum. To overcome these problems, three guar gum derivatives, carboxymethyl guar, carboxymethyl hydroxypropyl guar and hydroxypropyl guar, were tested as gelling agents for microbial growth and differentiation. These were also evaluated for their suitability for other routine microbiological methods, such as, enumeration, use of selective and differential media, and antibiotic sensitivity test. For evaluation purpose, growth and differentiation of eight fungi and eight bacteria grown on the media gelled with agar (1.5%), guar gum (4%) or one of the guar gum derivatives (4%), were compared. All fungi and bacteria exhibited normal growth and differentiation on all these media. Generally, growth of most of the fungi was better on guar gum derivatives gelled medium than on agar medium. The enumeration carried out for Serratia sp. and Pseudomonas aeruginosa by serial dilution and pour plate method yielded similar counts in all the treatments. Likewise, the selective succinate medium, specific for P. aeruginosa, did not allow growth of co-inoculated Bacillus sp. even if gelled with guar gum derivatives. The differential medium, Congo red mannitol agar could not differentiate between Agrobacterium tumefaciens and Rhizobium meliloti on color basis, if gelled with guar gum or any of its derivatives However, for antibiotic sensitivity tests for both Gram-positive and -negative bacteria, guar gum and its derivatives were as effective as agar.

  7. Produção de goma xantana por fermentação do resíduo de suco de maçã Xanthan gum production by fermentation from residue of apple juice

    Directory of Open Access Journals (Sweden)

    Janice Izabel Druzian

    2007-03-01

    Full Text Available Goma xantana é um heteropolissacarídeo hidrosolúvel, produzida industrialmente por fermentação da sacarose por Xanthomonas campestris. Suas excelentes propriedades reológicas contribuem para o grande número de aplicações na indústria de alimentos e recuperação terciária de petróleo. Economicamnte a utilização petroquímica não é ainda viável em função do custo da sacarose, o que torna interessante estudar fontes de carbonos alternativas, como é o caso do resíduo do suco de maçã. As cepas de Xanthomonas campestris pv maniothis foram mantidas em agar YM a 4 °C, e o inóculo foi incubado em meio YM. A produção de goma foi realizada nos meios fermentativos I e II, com sacarose como fonte de carbono padrão, e como fonte alternativa o resíduo de maçã fuji. A fermentação em Incubadora/28 °C/150 rpm produziu goma precipitada em álcool. A condição otimizada de 45 g.L-1 de meio II (0,05% uréia, 0,5% de KH2PO4 e 70% de resíduo representou um rendimento 10 vezes maior do que o obtido com sacarose. Por CG-EM obteve-se 44,53% de manose, 34,76% de glicose e 20,71% de ácido glucurônico para a composição desta goma. O uso de resíduo de maçã para produção de goma xantana é viável porque pode ser usado com um substrato suplementar e apresentar rendimento de goma muito superior ao obtido com sacarose.Xanthan gum is heteropolysaccharide aquosoluble produced industrially for fermentation with sucrose by Xanthomonas campestris. Excellent gum rheological properties contribute to the use in a wide range of applications in the food industry and tertiary recovery of oil. Commercially, the use of petrochemical is no longer viable in the cost of sucrose, which makes it interesting to evaluate alternative carbon sources such as the residue from apple juice processing. The Xanthomonas campestris pv maniothis was maintained at 4 °C on YM agar slants and innocuous in a medium of YM. Gum production was carried out in

  8. X-ray diffraction, IR spectroscopy and thermal characterization of partially hydrolyzed guar gum.

    Science.gov (United States)

    Mudgil, Deepak; Barak, Sheweta; Khatkar, B S

    2012-05-01

    Guar gum was hydrolyzed using cellulase from Aspergillus niger at 5.6 pH and 50°C temperature. Hydrolyzed guar gum sample was characterized using Fourier transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, X-ray diffraction, dilute solution viscometry and rotational viscometry. Viscometry analysis of native guar gum showed a molecular weight of 889742.06, whereas, after enzymatic hydrolysis, the resultant product had a molecular weight of 7936.5. IR spectral analysis suggests that after enzymatic hydrolysis of guar gum there was no major transformation of functional group. Thermal analysis revealed no major change in thermal behavior of hydrolyzed guar gum. It was shown that partial hydrolysis of guar gum could be achieved by inexpensive and food grade cellulase (Aspergillus niger) having commercial importance and utilization as a functional soluble dietary fiber for food industry.

  9. Optimization of enzymatic hydrolysis of guar gum using response surface methodology.

    Science.gov (United States)

    Mudgil, Deepak; Barak, Sheweta; Khatkar, B S

    2014-08-01

    Guar gum is a polysaccharide obtained from guar seed endosperm portion. Enzymatically hydrolyzed guar gum is low in viscosity and has several health benefits as dietary fiber. In this study, response surface methodology was used to determine the optimum conditions for hydrolysis that give minimum viscosity of guar gum. Central composite was employed to investigate the effects of pH (3-7), temperature (20-60 °C), reaction time (1-5 h) and cellulase concentration (0.25-1.25 mg/g) on viscosity during enzymatic hydrolysis of guar (Cyamopsis tetragonolobus) gum. A second order polynomial model was developed for viscosity using regression analysis. Results revealed statistical significance of model as evidenced from high value of coefficient of determination (R(2) = 0.9472) and P guar gum as potential source of soluble dietary fiber for human health benefits.

  10. Electrospun Nanofibers of Guar Galactomannan for Targeted Drug Delivery

    Science.gov (United States)

    Chu, Hsiao Mei Annie

    2011-12-01

    Guar galactomannan is a biodegradable polysaccharide used widely in the food industry but also in the cosmetics, pharmaceutical, oil drilling, textile and paper industries. Guar consists of a mannose backbone and galactose side groups that are both susceptible to enzyme degradation, a unique property that can be explored for targeted drug delivery especially since those enzymes are naturally secreted by the microflora in human colon. The present study can be divided into three parts. In the first part, we discuss ways to modify guar to produce nanofibers by electrospinning, a process that involves the application of an electric field to a polymer solution or melt to facilitate production of fibers in the sub-micron range. Nanofibers are currently being explored as the next generation of drug carriers due to its many advantages, none more important than the fact that nanofibers are on a size scale that is a fraction of a hair's width and have large surface-to-volume ratio. The incorporation and controlled release of nano-sized drugs is one way in which nanofibers are being utilized in drug delivery. In the second part of the study, we explore various methods to crosslink guar nanofibers as a means to promote water-resistance in a potential drug carrier. The scope and utility of water-resistant guar nanofibers can only be fully appreciated when subsequent drug release studies are carried out. To that end, the third part of our study focuses on understanding the kinetics and diffusion mechanisms of a model drug, Rhodamine B, through moderately-swelling (crosslinked) hydrogel nanofibers in comparison to rapidly-swelling (non-crosslinked) nanofibers. Along the way, our investigations led us to a novel electrospinning set-up that has a unique collector designed to capture aligned nanofibers. These aligned nanofiber bundles can then be twisted to hold them together like yarn. From a practical standpoint, these yarns are advantageous because they come freely suspended and

  11. The Digestion of Guar Gum by Individual Strains of Colonic Bacteria

    OpenAIRE

    Tomlin, J.; Read, N W; Edwards, C. A.; Duerden, B. I.

    2011-01-01

    Experiments were carried out to determine the range of human colonic bacteria that could ferment the viscous polysaccharide, guar gum, and to seek evidence for collaboration between different strains of colonic bacteria. Single strains of a variety of species of bacteria isolated from human faeces were incubated with guar gum. Only seven ofthe 57 different strains of bacteria tested could alter the viscosity and pH of guar gum. These seven strains were all of the fragilis group of the genus B...

  12. Chemical and Physical Properties, Safety and Application of Partially Hydrolized Guar Gum as Dietary Fiber

    OpenAIRE

    2007-01-01

    The ideal water-soluble dietary fiber for the fiber-enrichment of foods must be very low in viscosity, tasteless, odorless, and should produce clear solutions in beverages. Partially hydrolyzed guar gum (PHGG) produced from guar gum by enzymatic process has the same chemical structure with intact guar gum but less than one-tenth the original molecular length of guar gum, which make available to be used as film former, foam stabilizer and swelling agent. The viscosity of PHGG is about 10 mPa·s...

  13. Dietary guar gum reduces lymph flow and diminishes lipid transport in thoracic duct-cannulated rats.

    Science.gov (United States)

    Shirouchi, Bungo; Kawamura, Sayaka; Matsuoka, Ryosuke; Baba, Sanae; Nagata, Kazuko; Shiratake, Sawako; Tomoyori, Hiroko; Imaizumi, Katsumi; Sato, Masao

    2011-08-01

    Guar gum has a well-recognized hypolipidemic effect. This effect is thought to be due to the physicochemical properties of guar gum, which may cause changes in adsorption of lipids or the viscosity of the intestinal contents. Guar gum is a non-specific absorption inhibitor of any type of lipid-soluble compound. Permanent lymph duct cannulation was performed on rats to investigate the effects of dietary guar gum on lymph flow and lipid transport. Rats fed a 5% guar gum diet were compared with those fed a 5% cellulose diet, and lymph was collected after feeding. The water-holding capacity (WHC), settling volume in water (SV), and viscosity of guar gum were compared with those of cellulose. Rats fed with the guar gum diet had significantly lower lymph flow and lymphatic lipid transport than did rats fed with the cellulose diet. The WHC, SV, and viscosity of guar gum were significantly higher than those of cellulose. We propose that dietary guar gum reduces lymph flow and thereby diminishes lipid transport by means of its physicochemical properties related to water behavior in the intestine.

  14. Why treatment centres failed to prevent cholera deaths among Rwandan refugees in Goma, Zaire.

    Science.gov (United States)

    Siddique, A K; Salam, A; Islam, M S; Akram, K; Majumdar, R N; Zaman, K; Fronczak, N; Laston, S

    1995-02-11

    In July, 1994, in one of the worst cholera outbreaks in recent times, an estimated 12,000 Rwandan refugees died in Goma in eastern Zaire. The Vibrio cholerae strains were resistant to tetracycline and doxycycline, the commonly used drugs for cholera treatment. Despite the efforts of international organisations, which provided medical relief by establishing treatment centres in Goma, mortality from the disease was much higher than expected. In the area of Muganga camp, which had the largest concentration of refugees and where most of the medical aid organisations were active, the highest reported case-fatality ratio for a single day was 48%. The slow rate of rehydration, inadequate use of oral rehydration therapy, use of inappropriate intravenous fluids, and inadequate experience of health workers in management of severe cholera are thought to be some of the factors associated with the failure to prevent so many deaths during the epidemic. In one of the temporary treatment centres with the worst case-fatality record, our team showed that improvement of these factors could increase the odds of survival of cholera patients even in a disaster setting.

  15. Low viscosity hydrogel of guar gum: preparation and physicochemical characterization.

    Science.gov (United States)

    Cunha, Pablyana L R; Castro, Rondinelle R; Rocha, Francisco A C; de Paula, Regina C M; Feitosa, Judith P A

    2005-10-30

    Guar gum was cross-linked with glutaraldehyde and characterized by GPC, rheology, WADX, SEM and TGA. This guar gum is a galactomannan polysaccharide, that contains small amount of arabinose, glucose and uronic acid, besides galactose and mannose. The polymer has high molar mass, with Mw, Mn and Mv values of 2.0x10(6), 1.2x10(6) and 1.9x10(6)g/mol, respectively. The reticulation follows a slow process and lead to a viscosity increase of 40 times compared with the original gum solution. The final viscosity was similar to that of Hylan G-F 20, a hyaluronate derivative, commercially used in viscosupplementation treatment. The gel contains 95.6% of water and the amount of residual glutaraldehyde is much lower than the LD-50. Porous structure was detected by SEM and thermal stability was improved by the cross-linking. The low viscosity, the small amount of remained glutaraldehyde, and the thermal stability indicates that the guar hydrogel has potential to be applied as biomaterial with specific rheological requirements.

  16. Facing medical care problems of victims of sexual violence in Goma/Eastern Democratic Republic of the Congo

    Directory of Open Access Journals (Sweden)

    Dünser Martin W

    2011-03-01

    Full Text Available Abstract Background Since 1998, the Eastern Democratic Republic of the Congo has been torn by a military conflict. A particular atrocity of the war is widespread sexual violence. Methods In this combined retrospective analysis and prospective survey, we sought to identify hospital facilities and resources available to treat victims of sexual violence in Goma, the capital city of the North Kivu province. Results Of twenty-three acute care hospitals registered in the area of Goma, four (17% regularly cared for victims of sexual violence. One hospital had all resources always available to appropriately care for victims of sexual violence. From Jan 2009 until Oct 2010, 7,048 females sought medical care because of physical or psychological sequelae from sexual violence in the four hospitals of Goma. Only half of the hospitals had physicians specialized in gynaecology or gynaecological surgery available. Similarly, anaesthetists and psychiatrists/psychologists were available in two (50% and one (25% hospital, respectively. Post-discharge care facilities, material resources, such as surgical and anaesthesiological equipment and drugs, were inconsistently available in the hospitals caring for sexually abused females. At one selected hospital, acyclovir and/or antibiotics were administered to 1,202 sexually abused females (89.5%, whereas post-exposure HIV prophylaxis and surgery because of vesico-vaginal fistula was provided to only 75 (5.6% and 121 (9% patients, respectively. Conclusions This study provides data that only few hospitals in Goma care for victims of sexual violence. In addition, these hospitals suffer from a relevant shortage of human and material resources to provide adequate care for sexually abused females. Aside from establishment of adequate protection strategies, steps must be taken to increase the availability of trained health care professionals and resources to provide adequate care for victims of sexual violence in Goma and the

  17. Water vapor permeability, mechanical, optical and sensorial properties of plasticized guar gumedible films

    Science.gov (United States)

    Edible films were prepared by casting method using guar gum and glycerol in different ratios. The concentration of guar gum was 1.0, 1.5 and 2.0% whereas glycerol concentration was 20, 30 and 40% (w/v). The water vapor permeability (WVP), mechanical properties (tensile strength and elongation), thic...

  18. Ethanol-resistant ethylcellulose/guar gum coatings--importance of formulation parameters.

    Science.gov (United States)

    Rosiaux, Y; Velghe, C; Muschert, S; Chokshi, R; Leclercq, B; Siepmann, F; Siepmann, J

    2013-11-01

    Recently, ethylcellulose/guar gum blends have been reported to provide ethanol-resistant drug release kinetics from coated dosage forms. This is because the ethanol insoluble guar gum effectively avoids undesired ethylcellulose dissolution in ethanol-rich bulk fluids. However, so far the importance of crucial formulation parameters, including the minimum amount of guar gum to be incorporated and the minimum required guar gum viscosity, remains unclear. The aim of this study was to identify the most important film coating properties, determining whether or not the resulting drug release kinetics is ethanol-resistant. Theophylline matrix cores were coated in a fluid bed with blends of the aqueous ethylcellulose dispersion "Aquacoat®ECD30" and guar gum. The polymer blend ratio, guar gum viscosity, and degree of dilution of the final coating dispersion were varied. Importantly, it was found that more than 5% guar gum (referred to the total polymer content) must be incorporated in the film coating and that the apparent viscosity of a 1% aqueous guar gum solution must be greater than 150 cP to provide ethanol-resistance. In contrast, the investigated degree of coating dispersion dilution was not found to be decisive for the ethanol sensitivity. Furthermore, all investigated formulations were long term stable, even upon open storage under stress conditions for 6 months.

  19. Functional vegetable guar (Cyamopsis tetragonoloba L. Taub.) accessions for improving flavonoid concentrations in immature pods

    Science.gov (United States)

    Dry guar (Cyamopsis tetragonoloba L. Taub) seed are primarily used to extract galactomannan gum for oil fracking, however the immature pods are used as a vegetable in India and sold in ethnic grocery stores in the Atlanta, GA area. Twenty-two guar genotypes were grown in the field at Griffin, GA, US...

  20. Prospective of guar gum and its derivatives as controlled drug delivery systems.

    Science.gov (United States)

    Prabaharan, M

    2011-08-01

    Guar gum is a non-ionic polysaccharide that is found abundantly in nature and has many properties desirable for drug delivery applications. However, due to its high swelling characteristics in aqueous solution, the use of guar gum as delivery carriers is limited. Guar gum can be modified by derivatization, grafting and network formation to improve its property profile for a wide spectrum of biomedical applications. This review article is aimed at focusing the recent efforts and developments on guar gum and its derivatives as colon-specific, antihypertensive, protein and transdermal drug delivery systems. Based on the literatures reviewed, it is concluded that guar gum and its derivatives in the various forms such as coatings, matrix tablets, hydrogels and nano/microparticles can be exploited as potential carriers for targeted drug delivery.

  1. Irradiation depolymerized guar gum as partial replacement of gum Arabic for microencapsulation of mint oil.

    Science.gov (United States)

    Sarkar, Shatabhisa; Gupta, Sumit; Variyar, Prasad S; Sharma, Arun; Singhal, Rekha S

    2012-11-06

    Spray dried microcapsules of mint oil were prepared using gum Arabic alone and its blends with radiation or enzymatically depolymerized guar gum as wall materials. Microcapsules were evaluated for retention of mint oil during 8-week storage during which qualitative changes in encapsulated mint oil was monitored using principal component analysis. The microcapsules with radiation depolymerized guar gum as wall material component could better retain major mint oil compounds such as menthol and isomenthol. The t(1/2) calculated for mint oil in microcapsules of gum Arabic, gum Arabic:radiation depolymerized guar gum (90:10), gum Arabic:enzyme depolymerized guar gum (90:10) was 25.66, 38.50, and 17.11 weeks, respectively. The results suggested a combination of radiation depolymerized guar gum and gum Arabic to show better retention of encapsulated flavour than gum Arabic alone as wall material.

  2. Selective depression behavior of guar gum on talc-type scheelite flotation

    Science.gov (United States)

    Zhang, Yong-zhong; Gu, Guo-hua; Wu, Xiang-bin; Zhao, Kai-le

    2017-08-01

    The depression behavior and mechanism of guar gum on talc-type scheelite flotation were systematically investigated by flotation experiments, adsorption tests, zeta-potential measurements, and infrared spectroscopic analyses. The flotation results for monominerals, mixed minerals, and actual mineral samples indicated that guar gum exhibited much higher selective depression for talc than for scheelite. Bench-scale closed-circuit tests showed that a tungsten concentrate with a WO3 grade of 51.43% and a WO3 recovery of 76.18% was obtained. Adsorption tests, zeta-potential measurements, and infrared spectral analyses confirmed that guar gum absorbed more strongly onto the talc surface than onto the scheelite surface because of chemisorption between guar gum and talc. This chemisorption is responsible for the guar gum's highly selective depression for talc and small depression for scheelite. The flotation results provide technical support for talc-type scheelite flotation.

  3. Efeito de diferentes tipos de fibras sobre frações lipídicas do sangue e fígado de ratos wistar Effect of different types of fibers on the lipid portions of wistar rat blood and liver

    Directory of Open Access Journals (Sweden)

    Moacir Robson Eufrásio

    2009-12-01

    Full Text Available Conduziu-se o presente estudo, com o objetivo de avaliar o efeito de diferentes tipos de fibras sobre as fraçoes lipídicas do sangue e fígado de ratos. Para determinar o efeito da pectina citrica, goma guar e celulose sobre o perfil lipidico dos ratos utilizaramse 36 ratos machos da linhagem wistar. Os ratos foram distribuidos aleatoreamente em seis grupos. Cada gruopo foi submetido a uma dieta por 58 dias. As dietas utilizadas foram: A- 10% de pectina, B - 15% de pectina, C - 10% de goma guar, D- 15% de goma guar, E - 5% de Celulose sem colesterol e F - 5% celulose com 1% de colesterol. A pectina e a goma guar evitaram o aumento do colesterol total e LDL-c sérico observado na dieta F (pThe present study was designed to evaluate the effect of different types of fibers on lipid portions of mice blood and liver. To determine the effect of citric pectin, guar gum and cellulose on the rat lipid profile, 36 male mice of the Wistar strain were utilized. The mice were allocated randomly into six groups. Each group was submitted to an experimental diet for 58 days. The utilized diets were: A- 10% pectin, B - 15% pectin, C - 10% guar gum, D- 15% guar gum, E - 5% cellulose with no cholesterol and F - 5% cellulose with 1% cholesterol. Pectin and guar gum prevented the increase of total cholesterol and serum LDL-c found in diet F (p<0.05. There was no significant difference among the types of soluble fibers and the amounts utilized. The serum levels HDL-c, VLDL-c, and TAG did not alter in all the treatments. The results show the potential beneficial effect of the ingestion of the soluble fibers pectin and guar gum in cholesterolemia control.

  4. Guar gum solutions for improved delivery of iron particles in porous media (Part 1): Porous medium rheology and guar gum-induced clogging

    Science.gov (United States)

    Gastone, Francesca; Tosco, Tiziana; Sethi, Rajandrea

    2014-10-01

    The present work is the first part of a comprehensive study on the use of guar gum to improve delivery of microscale zero-valent iron particles in contaminated aquifers. Guar gum solutions exhibit peculiar shear thinning properties, with high viscosity in static conditions and lower viscosity in dynamic conditions: this is beneficial both for the storage of MZVI dispersions, and also for the injection in porous media. In the present paper, the processes associated with guar gum injection in porous media are studied performing single-step and multi-step filtration tests in sand-packed columns. The experimental results of single-step tests performed by injecting guar gum solutions prepared at several concentrations and applying different dissolution procedures evidenced that the presence of residual undissolved polymeric particles in the guar gum solution may have a relevant negative impact on the permeability of the porous medium, resulting in evident clogging. The most effective preparation procedure which minimizes the presence of residual particles is dissolution in warm water (60 °C) followed by centrifugation (procedure T60C). The multi-step tests (i.e. injection of guar gum at constant concentration with a step increase of flow velocity), performed at three polymer concentrations (1.5, 3 and 4 g/l) provided information on the rheological properties of guar gum solutions when flowing through a porous medium at variable discharge rates, which mimic the injection in radial geometry. An experimental protocol was defined for the rheological characterization of the fluids in porous media, and empirical relationships were derived for the quantification of rheological properties and clogging with variable injection rate. These relationships will be implemented in the second companion paper (Part II) in a radial transport model for the simulation of large-scale injection of MZVI-guar gum slurries.

  5. Paul Goma. Sabina: Social Avatars and the Vectors of creating the “New-Man”

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    Mariana PASINCOVSCHI

    2012-06-01

    Full Text Available Interested in building the novel based on real events and providing another version of reality, having as primary target the description of a society in which the lack of modesty is an essential feature of the “normality”, Paul Goma takes a proper route avoiding the linearity and faithfully reflecting the disorder of the evoked world. Being an agent of systematization, the narrator shows how the vectors of creating the “new-man” act: Lie, Fear, Terror, Concessions, Reeducation, Equalization and Suspendationalism, creating an autonomous and essential whole. Without having the possibility to shirk, “history is [emphasis added] the woman, with all her versatility and betrayal”, spirally expressed, in communion with the writer’s style. Therefore, in order to support the narrative pulse, feeling the writing in his fingers, the narrator combines the two “realities”, identifying the existence with the transcendence and balancing them through the dignity he demonstrates in both plans.

  6. Humanitarian presence and urban development: new opportunities and contrasts in Goma, DRC.

    Science.gov (United States)

    Büscher, Karen; Vlassenroot, Koen

    2010-04-01

    This paper examines the impact of the presence of international humanitarian organisations on local urban transformation processes in the city of Goma, Democratic Republic of the Congo (DRC). Rather than evaluating the direct effects of humanitarian interventions and strategies, it focuses on the indirect but profound effects of the presence of this 'humanitarian sector'. It argues that the international humanitarian presence became a significant factor in the recent shaping and reshaping of the city's profile and has reinforced competition over the urban political and socioeconomic space. The paper evaluates the direct and indirect impact of the international humanitarian presence on the local urban economy and the larger political economy of war in eastern DRC. It analyses how this presence has reinforced processes of spatial reconfiguration, how it has influenced urban planning, and how it has affected dynamics of gentrification and marginalisation on the urban spatial level.

  7. Knowledge and attitude of schoolgirls about illegal abortions in Goma, Democratic Republic of Congo

    Directory of Open Access Journals (Sweden)

    Lussy J. Paluku

    2010-03-01

    Full Text Available Background: Adolescent sexual activity, early pregnancy, induced abortion and the increase in HIV infection have become major concerns in sub-Saharan Africa and understanding adolescent sexual behaviour remains a challenge. In the Democratic Republic of Congo (DRC, the practice of illegal abortions is prevalent among school-going adolescent girls with unplanned pregnancies. Assessing their attitude and knowledge on the subject could be a starting point from which to address the problem.Objectives: To determine the knowledge of schoolgirls in Goma, DRC about the health consequences of illegal abortions and to assess their attitude towards these abortions.Method: A descriptive cross-sectional study was conducted among a randomly selected sample of 328 high school girls aged 16 to 20 years. A pre-tested, self-administered questionnaire was used for data collection. Nine out of 55 (11 public and 44 private secondary schools were randomly selected for inclusion in the study. The Epi-Info 2000 computer program was used for data capturing and analysis.Results: The different sources of information were the radio (66.2%, 217, friends (31.7%, 104, parents (1.5%, 5, and the church (0.5%, 2. The health consequences of illegal abortion mentioned were death, infertility, infection and bleeding. Of the participants, 9.8% (32 had committed an abortion before and 46% (151 knew where to obtain it; 76.2% (250 of participants were against illegal abortion, while 23.8% (78 supported it.Conclusion: Girls in secondary school in Goma had good knowledge of the illegal abortion practice and its consequences. A fifth of them were in support of the procedure. The DRC government may need to consider legalising abortion to secure a healthy future for affected girls.

  8. Knowledge and attitude of schoolgirls about illegal abortions in Goma, Democratic Republic of Congo

    Directory of Open Access Journals (Sweden)

    Lussy J. Paluku

    2010-03-01

    Full Text Available Background: Adolescent sexual activity, early pregnancy, induced abortion and the increase in HIV infection have become major concerns in sub-Saharan Africa and understanding adolescent sexual behaviour remains a challenge. In the Democratic Republic of Congo (DRC, the practice of illegal abortions is prevalent among school-going adolescent girls with unplanned pregnancies. Assessing their attitude and knowledge on the subject could be a starting point from which to address the problem.Objectives: To determine the knowledge of schoolgirls in Goma, DRC about the health consequences of illegal abortions and to assess their attitude towards these abortions.Method: A descriptive cross-sectional study was conducted among a randomly selected sample of 328 high school girls aged 16 to 20 years. A pre-tested, self-administered questionnaire was used for data collection. Nine out of 55 (11 public and 44 private secondary schools were randomly selected for inclusion in the study. The Epi-Info 2000 computer program was used for data capturing and analysis.Results: The different sources of information were the radio (66.2%, 217, friends (31.7%, 104, parents (1.5%, 5, and the church (0.5%, 2. The health consequences of illegal abortion mentioned were death, infertility, infection and bleeding. Of the participants, 9.8% (32 had committed an abortion before and 46% (151 knew where to obtain it; 76.2% (250 of participants were against illegal abortion, while 23.8% (78 supported it.Conclusion: Girls in secondary school in Goma had good knowledge of the illegal abortion practice and its consequences. A fifth of them were in support of the procedure. The DRC government may need to consider legalising abortion to secure a healthy future for affected girls.

  9. Nuevas representaciones rupestres en Ojo Guareña (Burgos

    Directory of Open Access Journals (Sweden)

    Francisco JORDÁ CERDÁ

    2009-10-01

    Full Text Available Traemos hoy a estas páginas una simple información acerca de unos nuevos descubrimientos de pinturas y grabados rupestres en la Cueva Palomera de Ojo Guareña. Necesariamente habrá que realizar en la citada cueva una investigación completa e intensiva, ya que los hallazgos, como vamos a ver, presentan aspectos en cierto modo heterodoxos respecto al arte rupestre conocido. Como esta labor posiblemente sea larga, hemos preferido dar a conocer una visión rápida de los aspectos más interesantes que estos meses atrás se pusieron al descubierto.

  10. Production of secreted guar α-galactosidase by Lactococcus lactis

    OpenAIRE

    Leenhouts, K J; Bolhuis, A; Ledeboer, A.; Venema, G; Kok, J

    1995-01-01

    A plant α-galactosidase gene was inserted in the expression vector pGKV259. The resulting plasmid pGAL2 consisted of the replication functions of the broad-host-range lactococcal plasmid pWV01, the lactococcal promoter P59, and the DNA sequences encoding the α-amylase signal sequence from Bacillus amyloliquefaciens and the mature part of the α-galactosidase from Cyamopsis tetragonoloba (guar). Lactococcus cells of strain MG1363 harbouring this vector produced the plant α-galactosidase and sec...

  11. Reactivity recovery of guar gum coupled mZVI by means of enzymatic breakdown and rinsing

    Science.gov (United States)

    Velimirovic, Milica; Chen, Hong; Simons, Queenie; Bastiaens, Leen

    2012-11-01

    Microscale zerovalent iron (mZVI) reduces chlorinated aliphatic hydrocarbons (CAHs) to harmless compounds, but the sedimentation of the mZVI particles in the injection fluid limits the injectability of the particles during field applications. In this study, mZVI particles in suspension were stabilized by green polymer guar gum, which had a positive impact on mZVI stability, but decreased the reactivity of the particles towards CAHs by 1 to 8 times. Guar gum (GG) was found to adsorb onto the mZVI surface, inhibiting contact between the chlorinated compounds and the reactive iron surface. Indications were found for intermolecular hydrogen bonding between mZVI and the guar gum. Subsequent addition of commercially available enzymes resulted in the cleavage of the polysaccharide guar gum into lower molecular fragments, but not in improved reactivity. The reactivity recovery of guar gum coupled mZVI was recovered after intensive rinsing of the iron particles, removing the guar gum fragments from the particles. Overall, this study shows that CAHs can be treated efficiently by guar gum stabilized mZVI after reactivation by means of enzymatic breakdown and rinsing.

  12. Guar gum coupled microscale ZVI for in situ treatment of CAHs: continuous-flow column study.

    Science.gov (United States)

    Velimirovic, Milica; Simons, Queenie; Bastiaens, Leen

    2014-01-30

    A column study was performed under in situ conditions to evaluate to which extend the inactivation of the microscale zerovalent iron (mZVI) by guar gum occurs under continuous flow conditions. Five aquifer containing columns were set up under different conditions. Efficient removal of trichloroethene was observed for the column amended by mZVI. Stabilization of the mZVI with guar gum led to slightly reduced activity. More reduced reactivity was observed in the poisoned column containing guar gum stabilized mZVI. This confirms that soil microorganisms can degrade guar gum and that subsequent removal of the oligosaccharides by the groundwater flow (flushing effect) can reactivate the mZVI. After more than six months of continuous operation the columns were dismantled. DNA-based qPCR analysis revealed that mZVI does not significantly affect the bacterial community, while guar gum stabilized mZVI particles can even induce bacterial growth. Overall, this study suggests that the temporarily decreased mZVI reactivity due to guar gum, has a rather limited impact on the performance of in situ reactive zones. The presence of guar gum slightly reduced the reactivity of iron, but also slowed down the iron corrosion rate which prolongs the life time of reactive zone.

  13. In vitro evaluation of guar gum as a carrier for colon-specific drug delivery.

    Science.gov (United States)

    Prasad, Y V; Krishnaiah, Y S; Satyanarayana, S

    1998-02-12

    A novel tablet formulation for oral administration using guar gum as the carrier and indomethacin as a model drug has been investigated for colon-specific drug delivery using in vitro methods. Drug release studies under conditions mimicking mouth to colon transit have shown that guar gum protects the drug from being released completely in the physiological environment of stomach and small intestine. Studies in pH 6.8 phosphate buffered saline (PBS) containing rat caecal contents have demonstrated the susceptibility of guar gum to the colonic bacterial enzyme action with consequent drug release. The pre-treatment of rats orally with 1 ml of 2% w/v aqueous dispersion of guar gum for 3 days induced enzymes specifically acting on guar gum thereby increasing drug release. A further increase in drug release was observed with rat caecal contents obtained after 7 days of pre-treatment. The presence of 4% w/v of caecal contents obtained after 3 days and 7 days of enzyme induction showed biphasic drug release curves. The results illustrate the usefulness of guar gum as a potential carrier for colon-specific drug delivery. The study also reveals that the use of 4% w/v of rat caecal contents in PBS, obtained after 7 days of enzyme induction provide the best conditions for in vitro evaluation of guar gum.

  14. Analysis of cDNA libraries from developing seeds of guar (Cyamopsis tetragonoloba (L. Taub

    Directory of Open Access Journals (Sweden)

    Dixon Richard A

    2007-11-01

    Full Text Available Abstract Background Guar, Cyamopsis tetragonoloba (L. Taub, is a member of the Leguminosae (Fabaceae family and is economically the most important of the four species in the genus. The endosperm of guar seed is a rich source of mucilage or gum, which forms a viscous gel in cold water, and is used as an emulsifier, thickener and stabilizer in a wide range of foods and industrial applications. Guar gum is a galactomannan, consisting of a linear (1→4-β-linked D-mannan backbone with single-unit, (1→6-linked, α-D-galactopyranosyl side chains. To better understand regulation of guar seed development and galactomannan metabolism we created cDNA libraries and a resulting EST dataset from different developmental stages of guar seeds. Results A database of 16,476 guar seed ESTs was constructed, with 8,163 and 8,313 ESTs derived from cDNA libraries I and II, respectively. Library I was constructed from seeds at an early developmental stage (15–25 days after flowering, DAF, and library II from seeds at 30–40 DAF. Quite different sets of genes were represented in these two libraries. Approximately 27% of the clones were not similar to known sequences, suggesting that these ESTs represent novel genes or may represent non-coding RNA. The high flux of energy into carbohydrate and storage protein synthesis in guar seeds was reflected by a high representation of genes annotated as involved in signal transduction, carbohydrate metabolism, chaperone and proteolytic processes, and translation and ribosome structure. Guar unigenes involved in galactomannan metabolism were identified. Among the seed storage proteins, the most abundant contig represented a conglutin accounting for 3.7% of the total ESTs from both libraries. Conclusion The present EST collection and its annotation provide a resource for understanding guar seed biology and galactomannan metabolism.

  15. The role of an anaesthetist in a field hospital during the cholera epidemic among Rwandan refugees in Goma.

    Science.gov (United States)

    Ginosar, Y; Shapira, S C

    1995-12-01

    In 1849 John Snow, already the leading anaesthetic practitioner and innovator of his day, made a historic contribution to the epidemiology of infectious disease by his famous study of the distribution of cholera around the area of Broad Street in London. We report on our experience as anaesthetists in a field hospital, dispatched as part of the international rescue effort to Goma, Zaire, to help combat the effects of cholera among the Rwandan refugees.

  16. Self-healing guar gum and guar gum-multiwalled carbon nanotubes nanocomposite gels prepared in an ionic liquid.

    Science.gov (United States)

    Sharma, Mukesh; Mondal, Dibyendu; Mukesh, Chandrakant; Prasad, Kamalesh

    2013-10-15

    Guar gum is a galactomannan extracted from the seed of the leguminous shrub Cyamopsis tetragonoloba. It was found to form a soft viscoelastic gel in 1-butyl-3-methylimidazolium chloride, an ionic liquid at an optimized concentration of 10%w/v. A nanocomposite gel of the gum with enhanced strength could be prepared with 0.2%w/v of multiwalled carbon nanotubes (MWCNTs) in the ionic liquid. When the gels thus prepared were subjected to surface fractures or bisected completely, they found to self-heal at room temperature without any external interventions. The self-healing process could be repeated several times. These viscoelastic gel systems showed thixotropic nature and recovery of the storage modulus with time for several cycles was observed upon rheological investigations. The interaction took place between ionic liquid, guar gum and MWCNT was studied by SEM, TEM, FT-IR, powder XRD and rheometry. The results suggested that, upon standing at room temperature development of electrostatic interactions and the van der Waals interactions among the ionic liquid molecules facilitated the formation of reversible noncovalent bonds and eventually activated the self-healing in the gel systems through appropriate chain entanglements.

  17. Estabilidade da polpa de morango atomizada utilizando diferentes agentes carreadores

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    Maria Isabel Sousa Oliveira

    2013-12-01

    Full Text Available Este trabalho teve por objetivo avaliar o efeito de diferentes agentes carreadores (Maltodextrina 5DE, Maltodextrina 10DE, Goma arábica e Capsul® nas características físico-químicas (umidade, densidade, solubilidade, teor de antocianinas e atividade antioxidante da polpa de morango desidratada por atomização e armazenada à temperatura ambiente por 90 dias. A utilização dos diferentes agentes carreadores resultou em pós com valores de densidade aparente entre 0,40 e 0,52 g/cm³ e umidade menor do que 2,5%. Todas as amostras foram altamente solúveis, mas os pós obtidos com a Maltodextrina 5DE e com a Goma arábica apresentaram menor higroscopicidade. As isotermas de sorção obtidas foram do tipo III e o modelo de GAB foi o que melhor se ajustou aos dados experimentais. A amostra produzida com goma arábica apresentou a maior concentração de antocianinas e, consequentemente, maior valor de atividade antioxidante, tanto imediatamente após a secagem como ao longo de 90 dias de armazenamento. Os resultados obtidos indicaram que a goma arábica foi o agente carreador mais adequado para a produção de polpa de morango em pó.

  18. Effect of guar and xanthan gums on functional properties of mango (Mangifera indica) kernel starch.

    Science.gov (United States)

    Nawab, Anjum; Alam, Feroz; Haq, Muhammad Abdul; Hasnain, Abid

    2016-12-01

    The effects of different concentrations of guar and xanthan gums on functional properties of mango kernel starch (MKS) were studied. Both guar and xanthan gum enhanced the water absorption of MKS. The addition of xanthan gum appeared to reduce the SP (swelling power) and solubility at higher temperatures while guar gum significantly enhanced the SP as well as solubility of MKS. The addition of both gums produced a reinforcing effect on peak viscosity of MKS as compared to control. Pasting temperature of MKS was higher than that of starch modified by gums indicating ease of gelatinization. Guar gum played an accelerative effect on setback but xanthan gum delayed the setback phenomenon during the cooling of the starch paste. Both gums were found to be effective in reducing the syneresis while gel firmness was markedly improved. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Partially hydrolysed guar gum supplemented comminuted chicken diet in persistent diarrhoea: a randomised controlled trial

    OpenAIRE

    N. Alam; Meier, R.; Sarker, S; Bardhan, P.; Schneider, H.; Gyr, N

    2005-01-01

    Background: Partially hydrolysed guar gum (Benefiber) added to a diet is fermented in the colon, producing short chain fatty acids, which improve intestinal function, including colonic salt and water absorption.

  20. Effect of feeding guar meal on nutrient utilization and growth performance in Mahbubnagar local kids

    Science.gov (United States)

    Janampet, Razia Sultana; Malavath, Kishan Kumar; Neeradi, Rajanna; Chedurupalli, Satyanarayana; Thirunahari, Raghunandan

    2016-01-01

    Aim: This study was conducted to evaluate the growth performance and nutrient digestibility of guar meal, an unconventional protein-rich feed ingredient in kids in comparison to conventional groundnut cake. Materials and Methods: A total of 18 kids were randomly allotted to three groups, and T1 group was fed on basal diet, T2 and T3 groups were offered diet replacing groundnut cake at 50% and 100% with guar meal, respectively, for a period of 120-day. At the end of the growth trial, a digestibility trial was conducted to evaluate the nutrient utilization. Results: There was no significant difference in dry matter intake among three groups. Nutrient digestibilities were significantly higher (p<0.05) in kids fed T2 ration with 50% replacement of groundnut cake with guar meal. Conclusion: It can be concluded that guar meal can be incorporated at 50% level in the concentrate mixture of goats replacing groundnut cake without any adverse effects. PMID:27847410

  1. Preparation of Acetylated Guar Gum – Unsaturated Polyester Composites & Effect of Water on Their Properties

    Directory of Open Access Journals (Sweden)

    David D’Melo

    2012-07-01

    Full Text Available Guar gum has seen extensive use in blends, however, its application as a filler in thermoset composites has as yet not been investigated. The effect of the addition of guar gum and its acetyl derivatives on the kinetics of water diffusion in unsaturated polyester composites was studied. The effect of water on the mechanical properties of the composites was studied with respect to the nature of filler, filler concentration and time of immersion. All the mechanical properties were observed to decrease on exposure to water. Further, it was observed that acetylated guar gum, with a degree of substitution of 0.21, showed the best mechanical properties, surpassing the other filled composites and that of the pure unsaturated polyester. Thus, acetylated guar gum showed promise as eco-friendly filler in composite formulation.

  2. TECHNICAL NOTE: The strengthening effect of guar gum on the yield stress of magnetorheological fluid

    Science.gov (United States)

    Wu, Wei Ping; Zhao, Bin Yuan; Wu, Qing; Chen, LeSheng; Hu, Ke Ao

    2006-08-01

    In this paper we present a novel approach for producing obvious strengthening of the magnetorheological (MR) effect of MR fluids. Carbonyl iron powders coated with guar gum were used as magnetic particles in the MR fluid. Experimental results showed that inducing a guar gum coating not only greatly improved the sedimentation stability but also strengthened the yield stress of the MR fluid. An intermolecular force based model was proposed for explaining the strengthening effect.

  3. Guar gum/borax hydrogel: Rheological, low field NMR and release characterizations

    OpenAIRE

    Grassi, M; T. Coviello; Matricardi, P; Alhaique, F.; Farra, R; G. Tesei; S. Fiorentino; F. Asaro; Milcovich, G.

    2013-01-01

    Guar gum (GG) and Guar gum/borax (GGb) hydrogels are studied by means of rheology, Low Field Nuclear Magnetic Resonance (LF NMR) and model drug release tests. These three approaches are used to estimate the mesh size (ζ) of the polymeric network. A comparison with similar Scleroglucan systems is carried out. In the case of GGb, the rheological and Low Field NMR estimations of ζ lead to comparable results, while the drug release approach seems to underestimate ζ. Such discrepanc...

  4. Nonionic gelation agents prepared from hydroxypropyl guar gum.

    Science.gov (United States)

    Kono, Hiroyuki; Hara, Hideyuki; Hashimoto, Hisaho; Shimizu, Yuuichi

    2015-03-06

    Nonionic gels were prepared from hydroxypropyl guar gum (HPG) with different molar substitution degrees by crosslinking with ethylene glycol diglycidyl ether (EGDE). FTIR and solid-state NMR spectroscopy revealed that the crosslinking degree of HPG gels increased with the amount of EGDE used during the reaction; this result was also confirmed by the water mobility in the swollen gels. Rheological characterization revealed behaviors typical of true gels, and their viscoelastic behaviors strongly depended on the crosslinking degree. The HPG gels absorbed buffers, aqueous saline, and water, and the absorption was not affected by the ionic strength or pH of the solution. In addition, HPG gels with high crosslinking degrees and molar substitution degrees exhibited gelation ability toward protic organic solvents such as methanol, ethanol, and 1-propanol. These HPG gels may find application as gelation agents for many industrial uses.

  5. Comparison of guar gum from different sources for the preparation of prolonged-release or colon-specific dosage forms.

    Science.gov (United States)

    Acartürk, Füsun; Celkan, Armağan

    2009-01-01

    The aim of the present study was to compare some physicochemical properties of guar gum samples from different sources and thus to investigate the suitability of these samples for the formulation of either prolonged-release or colon-specific dosage forms. Twelve different guar gum samples from India, Pakistan and the USA were used. Theophylline was chosen as a model drug. The flow type of the guar gum samples was determined as pseudoplastic. The viscosity and the particle size of the guar gum samples were found to be the main parameters which could affect the drug release from matrix tablets. All of the guar gum samples are suitable for use in the preparation of prolonged-release matrix tablets. But, three of them, obtained from India and the USA, may be potentially the most suitable guar gum samples for the preparation of colon-specific dosage forms.

  6. Compatibility testing and rheological characterization in development of novel in situ guar gum-based ophthalmic dosage form

    Directory of Open Access Journals (Sweden)

    N G Nanjundaswamy

    2011-01-01

    Full Text Available Guar gum is derived from the seeds of Cyamopsis tetragonolobus. Guar has certain drawbacks such as uncontrolled rate of hydration, fall in viscosity on storage, susceptibility to microbial degradation, and turbidity in aqueous dispersion. Many of these drawbacks can be overcome by using guar derivatives. Guar derivatives upon contact with water hydrate to form hydrogels for controlled-release mechanism and show stimuli-responsive changes in their structural network, and hence, the drug release. The present investigation aims at screening guar derivative (hydroxyl propyl guar during preformulation stage by spectral (FTIR spectroscopy, thermal (differential scanning calorimetry (DSC, isothermal (HPLC technique, and rheological characterization for the development of stable in situ ophthalmic dosage using linezolid as the model drug.

  7. Kinetic study of the gum decomposition from brazilian gasoline; Estudo cinetico da decomposicao da goma oriunda de gasolina brasileira

    Energy Technology Data Exchange (ETDEWEB)

    Pivesso, Paulo Roberto; Galvao, Luzia Patricia Fernandes de Carvalho; Fernandes Junior, Valter Jose; Coutinho, Ana Carla S.L.S. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil); Souza, Antonio Gouveia de [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil)

    2004-07-01

    The modern gasoline contains in your composition insatured hydrocarbons that can be degraded by the action of the air, heat and substances presenting catalytic activity. The presence of air and heat promote oxidation reactions and polymerization, which promote the gum formation, that is a product with diverse characteristics. The petroleum and l the automobile industries have been investing in researches to lessen the gum undesirable effects. Nowadays, several products are added to the gasoline, for example, the surfactant additives, with the purpose to reduce the formation of deposits in the engine. This work evaluated the influence of a polyester amine addictive, used as the main active component in Brazilian gasoline. The gums were generated evaporating the gasolines according to the ASTM D 381 method. Two types of gum were obtained; the Common Washed Gum (White Sample) and the Additive based Washed Gum (Additive Sample). Both samples were characterized for thermal analysis and submitted for a kinetic study using the model-free method proposed by Vyazovkin. This approach was applied to the final stage of the gums decomposition, supplying the corresponding relative kinetic parameters, such as energy of activation and conversion (author)

  8. Effect of guar gum on glucose and lipid metabolism in white sea bream Diplodus sargus.

    Science.gov (United States)

    Enes, P; Pousão-Ferreira, P; Salmerón, C; Capilla, E; Navarro, I; Gutiérrez, J; Oliva-Teles, A

    2013-04-01

    The aim of this study was to assess the role of soluble non-starch polysaccharide (guar gum) on white sea bream Diplodus sargus, glucose and lipid metabolism. A control diet was formulated to contain 40 % crude protein, 14 % crude lipids and 35 % pregelatinized maize starch, and three other diets were formulated similar to the control diet except for guar gum, which was included at 4 % (diet GG4), 8 % (diet GG8) or 12 % (diet GG12). Diets were fed to the fish for 9 weeks on a pair-feeding scheme. Guar gum had no effect on growth performance, feed efficiency, glycaemia, cholesterolaemia and plasma triacylglyceride levels. Hepatic glucokinase and pyruvate kinase activities, liver glycogen content and liver insulin-like growth factor-I gene expression were not affected by dietary guar gum, while fructose-1,6-bisphosphatase activity was lower in fish fed guar gum-supplemented diets. Hepatic glucose-6-phosphate dehydrogenase activity was higher in fish fed diets GG4 and GG8 than in the control group. Overall, data suggest that in contrast to mammals guar gum had no effect on white sea bream glucose utilization and in lowering plasma cholesterol and triacylglyceride levels. However, it seems to contribute to lower endogenous glucose production.

  9. Glucose absorption, hormonal release and hepatic metabolism after guar gum ingestion

    Science.gov (United States)

    Simoes Nunes, C.; Malmlof, K.

    1992-01-01

    Six non-anaesthetized Large White pigs (mean body weight 59 +/- 1.7 kg) were fitted with permanent catheters in the portal vein, the brachiocephalic artery and the right hepatic vein and with electromagnetic flow probes around the portal vein and the hepatic artery. The animals were provided a basal none-fibre diet (diet A) alone or together with 6% guar gum (diet B) or 15% purified cellulose (diet C). The diets were given for 1 week and according to a replicated 3 x 3 latin-square design. On the last day of each adaptation period test meals of 800 g were given prior to blood sampling. The sampling was continued for 8 h. Guar gum strongly reduced the glucose absorption as well as the insulin, gastric inhibitory polypeptide (GIP) and insulin-like growth factor-1 (IGF-1) production. However, the reduction in peripheral blood insulin levels caused by guar gum was not associated with a change in hepatic insulin extraction. IGF-1 appeared to be strongly produced by the gut. The liver had a net uptake of the peptide. Ingestion of guar gum increased the hepatic extraction coefficient of gut produced IGF-1. Guar gum ingestion also appeared to decrease pancreatic glucagon secretion. Cellulose at the level consumed had very little effect on the parameters considered. It is suggested that the modulation of intestinal mechanisms by guar gum was sufficient to mediate the latter internal metabolic effects.

  10. Fluoride kinetics in saliva after the use of a fluoride-containing chewing gum Cinética de flúor na saliva após o uso de uma goma de mascar fluoretada

    Directory of Open Access Journals (Sweden)

    Maria Francisca Thereza Borro Bijella

    2005-12-01

    Full Text Available There is a relationship between the use of fluoride, the reduction of dental caries and the increase of dental fluorosis. The purpose of this study was to analyze the fluoride kinetics in saliva after using the HappydentTM chewing gum, which contains 3.38 mg of fluoride as monofluorophosphate. Fifteen 7-9-year-old volunteers were instructed to chew the gum TridentTM (control and HappydentTM on different days. Total saliva was collected for 3 minutes, at 0, 3, 6, 9, 15, 30 and 45 minutes after starting chewing. Salivary fluoride was analyzed with a fluoride-specific electrode (Orion 96-09 after acid hydrolysis. The data were analyzed by two-way analysis of variance and by Tukey’s post hoc test (p Há uma relação entre o uso de fluoretos, a redução na cárie e o aumento da fluorose dentária. O objetivo deste estudo foi analisar a cinética do flúor na saliva após o uso da goma de mascar Happydent®, que contém 3,38 mg de flúor como monofluorfosfato. A saliva foi coletada de 15 voluntários entre 7 e 9 anos de idade, durante 3 minutos nos intervalos de 0, 3, 6, 9, 15, 30 e 45 minutos. Inicialmente, a coleta foi realizada com o Trident® (controle e, após 24 h, a coleta foi repetida com a goma de mascar Happydent®. O flúor foi analisado com um eletrodo íon-específico (Orion 96-09 após a realização da hidrólise ácida. Os dados foram analisados através da análise de variância a dois critérios e pelo teste de Tukey (p < 0,05. A quantidade média ± dp (mg de flúor liberado na saliva foi 0,276 ± 0,126 e 0,024 ± 0,014 para o Happydent® e o Trident®, respectivamente. A quantidade de flúor nas amostras de saliva após o uso do Happydent® foi significativamente maior do que após o uso do Trident® em todos os tempos experimentais, com exceção dos períodos de 30 e 45 minutos. A alta quantidade de flúor na saliva após o uso do Happydent® poderia ser eficiente na prevenção da cárie dentária, o que deveria ser avaliado

  11. Cholera epidemics, war and disasters around Goma and Lake Kivu: an eight-year survey.

    Directory of Open Access Journals (Sweden)

    Didier Bompangue

    Full Text Available BACKGROUND: During the last eight years, North and South Kivu, located in a lake area in Eastern Democratic Republic of Congo, have been the site of a major volcano eruption and of numerous complex emergencies with population displacements. These conditions have been suspected to favour emergence and spread of cholera epidemics. METHODOLOGY/PRINCIPAL FINDINGS: In order to assess the influence of these conditions on outbreaks, reports of cholera cases were collected weekly from each health district of North Kivu (4,667,699 inhabitants and South Kivu (4,670,121 inhabitants from 2000 through 2007. A geographic information system was established, and in each health district, the relationships between environmental variables and the number of cholera cases were assessed using regression techniques and time series analysis. We further checked for a link between complex emergencies and cholera outbreaks. Finally, we analysed data collected during an epidemiological survey that was implemented in Goma after Nyiragongo eruption. A total of 73,605 cases and 1,612 deaths of cholera were reported. Time series decomposition showed a greater number of cases during the rainy season in South Kivu but not in North Kivu. Spatial distribution of cholera cases exhibited a higher number of cases in health districts bordering lakes (Odds Ratio 7.0, Confidence Interval range 3.8-12.9. Four epidemic reactivations were observed in the 12-week periods following war events, but simulations indicate that the number of reactivations was not larger than that expected during any random selection of period with no war. Nyiragongo volcanic eruption was followed by a marked decrease of cholera incidence. CONCLUSION/SIGNIFICANCE: Our study points out the crucial role of some towns located in lakeside areas in the persistence of cholera in Kivu. Even if complex emergencies were not systematically followed by cholera epidemics, some of them enabled cholera spreading.

  12. Green stabilization of microscale iron particles using guar gum: bulk rheology, sedimentation rate and enzymatic degradation.

    Science.gov (United States)

    Gastone, Francesca; Tosco, Tiziana; Sethi, Rajandrea

    2014-05-01

    Guar gum can be used to effectively improve stability and mobility of microscale zerovalent iron particles (MZVI) used in groundwater remediation. Guar gum is a food-grade, environment friendly natural polysaccharide, which is often used as thickening agent in a broad range of food, pharmaceutical and industrial applications. Guar gum solutions are non-Newtonian, shear thinning fluids, characterized by high viscosity in static conditions and low viscosity in dynamic conditions. In particular, the high zero shear viscosity guarantees the MZVI dispersion stability, reducing the sedimentation rate of the particles thus enabling its storage and field operations. In this work, a comprehensive rheological characterization of guar gum-based slurries of MZVI particles is provided. First, we derived a model to link the bulk shear viscosity to the concentration of guar gum and then we applied it for the derivation of a modified Stokes law for the prediction of the sedimentation rate of the iron particles. The influence of the preparation procedure (cold or hot dissolution and high shear processing) on the viscosity and on the stability of the suspensions was then assessed. Finally, the dosage and concentration of enzymes - an environment friendly breaker--were studied for enhancing and controlling the degradation kinetics of the suspensions. The derived empirical relationships can be used for the implementation of an iron slurry flow and transport model and for the design of full scale injection interventions. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Chemical and physical properties, safety and application of partially hydrolized guar gum as dietary fiber.

    Science.gov (United States)

    Yoon, Seon-Joo; Chu, Djong-Chi; Raj Juneja, Lekh

    2008-01-01

    The ideal water-soluble dietary fiber for the fiber-enrichment of foods must be very low in viscosity, tasteless, odorless, and should produce clear solutions in beverages. Partially hydrolyzed guar gum (PHGG) produced from guar gum by enzymatic process has the same chemical structure with intact guar gum but less than one-tenth the original molecular length of guar gum, which make available to be used as film former, foam stabilizer and swelling agent. The viscosity of PHGG is about 10 mPa.s in 5% aqueous solution, whereas 1% solution of guar gum shows range from 2,000 to 3,000 mPa.s. In addition, PHGG is greatly stable against low pH, heat, acid and digestive enzyme. For these reasons, PHGG seems to be one of the most beneficial dietary fiber materials. It also showed that interesting physiological functions still fully exert the nutritional function of a dietary fiber. PHGG has, therefore, been used primarily for a nutritional purpose and became fully integrated food material without altering the rheology, taste, texture and color of final products. PHGG named as Benefiber(R) in USA has self-affirmation on GRAS status of standard grade PHGG. PHGG named as Sunfiber(R) is now being used in various beverages, food products and medicinal foods as a safe, natural and functional dietary fiber in all over the world.

  14. Antihyperglycemic and antihyperlipidemic effects of guar gum on streptozotocin-induced diabetes in male rats

    Directory of Open Access Journals (Sweden)

    Samarghandian Saeed

    2012-01-01

    Full Text Available Background: Herbal medicine is widely used in the treatment of diseases like diabetes mellitus. We investigated the effects of guar gum in diabetic rats for the reduction of the risk of diabetes and cardiovascular disease. Dietary pattern emphasizing foods high in complex carbohydrates and fiber are associated with low blood glucose and cholesterol levels. Materials and Methods: Diet containing 0%, 5%, 10% and 20% (w/w guar gum was fed to diabetic rats for 28 days. Blood serum glucose, triglycerides, cholesterol, low-density lipoprotein cholesterol (LDL-C, high-density lipoprotein cholesterol levels, atherogenic index levels, body weights and food intake were monitored at 0, 7.14 and 28 days after induction of diabetes. Results: In spite of the fact that diabetes elevated blood lipids in all rats after 14 days, the guar gum diet significantly decreased the serum concentration of cholesterol, triacylglicerols and LDL-C and atherogenic index. The most significant result in this study was the reduction of blood glucose in diabetic rats treated with the guar gum diet after 28 days versus non- and glibenclamide-treated rats. The gum promoted a general improvement in the condition of the diabetic rats in body weight and food intake in comparison with nontreated rats. Conclusion: The results of this research suggest that guar gum was significantly effective in comparison with glibenclamide in the treatment of hyperlipidemia and hyperglycemia in diabetes rats. Therefore, it may be suggested as a reliable fiber in diabetic regimes in diabetic patients.

  15. Starch-guar gum extrudates: microstructure, physicochemical properties and in-vitro digestion.

    Science.gov (United States)

    von Borries-Medrano, Erich; Jaime-Fonseca, Mónica R; Aguilar-Méndez, Miguel A

    2016-03-01

    Starch-guar gum mixtures were obtained by extrusion using a three-variable Box-Behnken statistic design. Morphology, expansion index, viscosity, crystallinity and digestion in vitro of the extruded samples were analyzed through response surface methodology (RSM). The extrusion temperature and the moisture content were the factors that significantly affected the physicochemical properties of the samples. Starch-guar gum samples showed expansion index and viscosity up to 1.55 and 1400mPas, respectively. The crystallinity of the samples was modified by adding guar gum to the extrudates, showing correlation between long-range order (X-ray diffraction) and short-range order (FTIR spectroscopy). Guar induced microstructural changes and its role in gelatinization-melting processes was significant. The rate of glucose release decreased from 0.47 to 0.43mM/min when the extrusion temperature decreased. However, adding guar gum to starch had no significant effect on glucose release. Overall, the extrusion temperature and the moisture content were the factors that significantly affected the physicochemical properties of the extruded samples.

  16. Mechanical and barrier properties of guar gum based nano-composite films.

    Science.gov (United States)

    Saurabh, Chaturbhuj K; Gupta, Sumit; Bahadur, Jitendra; Mazumder, S; Variyar, Prasad S; Sharma, Arun

    2015-06-25

    Guar gum based nano-composite films were prepared using organically modified (cloisite 20A) and unmodified (nanofil 116) nanoclays. Effect of nanoclay incorporation on mechanical strength, water vapor barrier property, chromatic characteristics and opacity of films was evaluated. Nano-composites were characterized using X-ray scattering, FTIR and scanning electron microscopy. A nanoclay concentration dependent increase in mechanical strength and reduction in water vapor transmission rate was observed. Films containing nanofil 116 (2.5% w/w guar gum) and closite 20A (10% w/w guar gum) demonstrated a 102% and 41% higher tensile strength, respectively, as compared to the control. Lower tensile strength of cloisite 20A films as compared to nanofil 116 films was due to its incompatibility with guar gum. X-ray scattering analysis revealed that interstitial spacing between nanofil 116 and cloisite 20A sheets increased due to intercalation by guar gum polymer. This resulted in improved mechanical and barrier properties of nano-composites compared to control.

  17. Electrically conducting silver/guar gum/poly(acrylic acid) nanocomposite.

    Science.gov (United States)

    Abdel-Halim, E S; Al-Deyab, Salem S

    2014-08-01

    This article describes the synthesis of an electrically conducting silver/guar gum/poly(acrylic acid) nanocomposite hydrogel. The synthesis process started with grafting acrylic acid monomers onto the natural polymer guar gum by the use of ammonium persulphate as a free radical initiator in acid medium. Guar gum/poly(acrylic acid) graft copolymer was separated from the polymerization medium, purified and subjected to crosslinking treatment, using alkaline epichlorohydrin as a crosslinking agent. Silver nitrate solution was added during the crosslinking treatment in varying concentrations, that the reaction conditions affect crosslinking of guar gum/poly(acrylic acid) graft copolymer to a hydrogel, as well as reduction of silver nitrate to silver nanoparticles, giving rise to the formation of silver/guar gum/poly(acrylic acid) nanocomposite. Factors affecting the grafting reaction as well as those affecting the crosslinking/reduction treatment were optimized. The so synthesized nanocomposite hydrogel samples were fully characterized, regarding their contents of silver nanoparticles and swelling ratio. The electrical conductivity of the nanocomposite hydrogel was studied and it was found to be affected by the swelling ratio of the hydrogel as well as its content of silver nanoparticles.

  18. Synthesis of oxidized guar gum by dry method and its application in reactive dye printing.

    Science.gov (United States)

    Gong, Honghong; Liu, Mingzhu; Zhang, Bing; Cui, Dapeng; Gao, Chunmei; Ni, Boli; Chen, Jiucun

    2011-12-01

    The aim of this study was to prepare oxidized guar gum with a simple dry method, basing on guar gum, hydrogen peroxide and a small amount of solvent. To obtain a product with suitable viscosity for reactive dye printing, the effects of various factors such as the amount of oxidant and solvent, reaction temperature and time were studied with respect to the viscosity of reaction products. The product was characterized by Fourier transform infrared spectroscopy, size exclusion chromatography, scanning electron microscopy and differential scanning calorimetry. The hydrated rate of guar gum and oxidized guar gum was estimated through measuring the required time when their solutions (1%, w/v) reached the maximum viscosity. The effects of the salt concentration and pH on viscosity of the resultant product were studied. The mixed paste containing oxidized guar gum and carboxymethyl starch was prepared and its viscosity was determined by the viscometer. The rheological property of the mixed paste was appraised by the printing viscosity index. In addition, the applied effect of mixed paste in reactive dye printing was examined by assessing the fabric stiffness, color yield and sharp edge to the printed image in comparison with sodium alginate. And the results indicated that the mixed paste could partially replace sodium alginate as thickener in reactive dye printing. The study also showed that the method was low cost and eco-friendly and the product would have an extensive application in reactive dye printing.

  19. Rapid screening of guar gum using portable Raman spectral identification methods.

    Science.gov (United States)

    Srivastava, Hirsch K; Wolfgang, Steven; Rodriguez, Jason D

    2016-01-25

    Guar gum is a well-known inactive ingredient (excipient) used in a variety of oral pharmaceutical dosage forms as a thickener and stabilizer of suspensions and as a binder of powders. It is also widely used as a food ingredient in which case alternatives with similar properties, including chemically similar gums, are readily available. Recent supply shortages and price fluctuations have caused guar gum to come under increasing scrutiny for possible adulteration by substitution of cheaper alternatives. One way that the U.S. FDA is attempting to screen pharmaceutical ingredients at risk for adulteration or substitution is through field-deployable spectroscopic screening. Here we report a comprehensive approach to evaluate two field-deployable Raman methods--spectral correlation and principal component analysis--to differentiate guar gum from other gums. We report a comparison of the sensitivity of the spectroscopic screening methods with current compendial identification tests. The ability of the spectroscopic methods to perform unambiguous identification of guar gum compared to other gums makes them an enhanced surveillance alternative to the current compendial identification tests, which are largely subjective in nature. Our findings indicate that Raman spectral identification methods perform better than compendial identification methods and are able to distinguish guar gum from other gums with 100% accuracy for samples tested by spectral correlation and principal component analysis.

  20. Utilizing guar gum for development of "tabs in cap' system of losartan potassium for chronotherapeutics.

    Science.gov (United States)

    Gangwar, Guarav; Kumar, Anil; Pathak, Kamla

    2015-01-01

    The project was aimed to achieve biphasic pulsed drug release of losartan potassium by fabricating 'Tabs in cap' system wherein drug loaded tablets sandwiched the erodible guar gum time spacer tablet. The system was capsulated in non biodegradable body capped with water soluble cap. The system was investigated for in-vitro release and ex-vivo continuous dissolution-absorption and stability. The influence of spray dried lactose (SDL): guar gum ratio on lag time was investigated. In-vitro release capsule evidenced immediate release followed by delayed pulse (>90%) and a lag time 6h was achieved by maintaining an optimum ratio of SDL: guar gum in erodible guar gum tablet. Ex-vivo continuous dissolution-absorption study demonstrated two successive pulses for dissolution and indicated delay in absorption of drug. Histological study revealed viability of intestinal cells and the system had shelf- life of 15 months. Conclusively, using guar gum spacer tablet, biphasic pulsed drug release 'Tabs in Cap' system of losartan potassium was successfully developed that has potential for chronotherapeutics in hypertension.

  1. Preparation and in vitro evaluation of guar gum based triple-layer matrix tablet of diclofenac sodium.

    Science.gov (United States)

    Chavda, H V; Patel, M S; Patel, C N

    2012-01-01

    The objective of the present study was to design an oral controlled drug delivery system for sparingly soluble diclofenac sodium (DCL) using guar gum as triple-layer matrix tablets. Matrix tablet granules containing 30% (D1), 40% (D2) or 50% (D3) of guar gum were prepared by the conventional wet granulation technique. Matrix tablets of diclofenac sodium were prepared by compressing three layers one by one. Centre layer of sandwich like structure was incorporated with matrix granules containing DCL which was covered on either side by guar gum granule layers containing either 70, 80 or 87% of guar gum as release retardant layers. The tablets were evaluated for hardness, thickness, drug content, and drug release studies. To ascertain the kinetics of drug release, the dissolution profiles were fitted to various mathematical models. The in vitro drug release from proposed system was best explained by the Hopfenberg model indicating that the release of drug from tablets displayed heterogeneous erosion. D3G3, containing 87% of guar gum in guar gum layers and 50% of guar gum in DCL matrix granule layer was found to provide the release rate for prolonged period of time. The results clearly indicate that guar gum could be a potential hydrophilic carrier in the development of oral controlled drug delivery systems.

  2. Evaluation of alternatives to guar gum as tackifiers for hydromulch and as clumping agents for biodegradable cat litter

    Science.gov (United States)

    Guar gum is currently the principal gum used as a tackifier for hydromulch used in erosion control, and as a clumping agent in biodegradable cat litters. Due to recent severe price increases for guar gum, cheaper alternatives are being investigated. We examined several alternatives, including xanth...

  3. Development and characterization of guar gum nanoparticles for oral immunization against tuberculosis.

    Science.gov (United States)

    Kaur, Mandeep; Malik, Basant; Garg, Tarun; Rath, Goutam; Goyal, Amit K

    2015-05-01

    The main aim of this study was to develop an effective carrier system containing Ag85A-loaded guar gum nanoparticles for oral vaccination against tuberculosis. Nanoparticles were prepared by Nanoprecipitation method. The developed particles with mean diameter 895.5 ± 14.73 nm and high antigen entrapment seem to be optimum for oral vaccine delivery. The acid protection assay, Peyer's patch uptake study and in-vitro antigen study confirmed that the developed formulations can protect the antigen from harsh gastric environment and can safely deliver the antigen to the intestinal region. In vivo studies data indicated that the developed nanocarriers can induce a strong mucosal as well as systemic immune response. Therefore, the experimental evidence suggests that guar-gum nanoparticle findings indicated that the guar gum nanoparticles can be utilized for safe and effective vaccine delivery via oral route.

  4. Guar gum and scleroglucan interactions with borax: experimental and theoretical studies of an unexpected similarity.

    Science.gov (United States)

    Bocchinfuso, Gianfranco; Mazzuca, Claudia; Sandolo, Chiara; Margheritelli, Silvia; Alhaique, Franco; Coviello, Tommasina; Palleschi, Antonio

    2010-10-21

    Guar gum is a galactomannan that assumes a very flexible conformation in solution, while Scleroglucan is a very rigid polysaccharide that dissolves in water as triple helices. Both polymers can form gels in the presence of borax. Despite their structural differences, the freeze-dried gel systems of both polymers, when compressed to form tablets, show a peculiar anisotropic swelling in water that reflects an amazing similarity in terms of their molecular properies. In this paper the behavior of the Guar/borax gel is compared with that of Scleroglucan/borax. The macroscopic properties of the two systems were characterized in terms of rheological measurements. Atomic force microscopy images and molecular dynamics simulation allowed to evaluate, at molecular level, the effect of borax addition to the Guar polymer. Both experiments show that an increasing of the polymer rigidity is produced by borax. The role played by galactose in the side chain was also discussed.

  5. Cationic guar gum orchestrated environmental synthesis for silver nano-bio-composite films.

    Science.gov (United States)

    Abdullah, Md Farooque; Ghosh, Sumanta Kumar; Basu, Sreyasree; Mukherjee, Arup

    2015-12-10

    This work is meant for environmentally friendly synthesis and functional evaluation of silver nanoparticles in a newer cationic guar biopolymer (GGAA). Assembly of molecules in lower size range (∼ 10 nm) was attained in a biopolymer entrapped bottom-up synthesis. Guar gum is a filming biopolymer. Nanoparticles encaged in cationic guar (GGAgnC) were preserved as films for months without any significant effect on particle size, distribution or plasmonic intensity. The new nano-bio-composite and films were characterized fully in FTIR, XRD, SEM and TEM studies. Silver nanoparticles induced surface water repellency remarkably and lowered moisture permeability. GGAgnC film water contact angle was recorded as 115° while, that in case of GGAA was 59°. GGAgnC expressed intense antimicrobial activity when tested against a range of microorganisms. Immobilized silver nanoparticles in GGAA can feasibly be used as filming microbicidals suitable for textiles, packaging and biomedical device applications.

  6. Effect of pH on the rheological properties of borate crosslinked hydroxypropyl guar gum hydrogel and hydroxypropyl guar gum.

    Science.gov (United States)

    Wang, Shibin; Tang, Hongbiao; Guo, Jianchun; Wang, Kunjie

    2016-08-20

    pH is an important factor affecting the performance of polymer fluid. The rheological properties of hydroxypropyl guar gum (HPG) base fluid and the structural strength, rheological properties, viscoelastic properties and thixotropy properties of HPG gel depend largely on the pH values. For the base fluid, an apparent viscosity-increasing effect was observed over the pH range from 7 to 11, and the apparent viscosity gradually decreased at pH 11.5-14, exhibiting electrostatic repulsion behavior and steric effects. For the HPG gel, at pH 7-12.5, the gel possessed higher apparent viscosity, higher elastic modulus (G'), lower tanδ (the ratio of the viscous modulus to the elastic modulus) and an "8"-shaped hysteresis loop, indicating stronger gel structure strength and the elastic dominant property. At pH 13-13.5, the gel samples exhibited the transition from a pseudoplastic fluid to a Newtonian fluid, and their viscosity, elastic modulus decreased but tanδ increased with the increase in pH values, exhibiting gradually weakened elastic properties. When the pH was 14, the gel mainly exhibited viscous characteristics.

  7. Guar gum, xanthan gum, and HPMC can define release mechanisms and sustain release of propranolol hydrochloride.

    Science.gov (United States)

    Mughal, Muhammad Akhlaq; Iqbal, Zafar; Neau, Steven Henry

    2011-03-01

    The objectives were to characterize propranolol hydrochloride-loaded matrix tablets using guar gum, xanthan gum, and hydroxypropylmethylcellulose (HPMC) as rate-retarding polymers. Tablets were prepared by wet granulation using these polymers alone and in combination, and physical properties of the granules and tablets were studied. Drug release was evaluated in simulated gastric and intestinal media. Rugged tablets with appropriate physical properties were obtained. Empirical and semi-empirical models were fit to release data to elucidate release mechanisms. Guar gum alone was unable to control drug release until a 1:3 drug/gum ratio, where the release pattern matched a Higuchi profile. Matrix tablets incorporating HPMC provided near zero-order release over 12 h and erosion was a contributing mechanism. Combinations of HPMC with guar or xanthan gum resulted in a Higuchi release profile, revealing the dominance of the high viscosity gel formed by HPMC. As the single rate-retarding polymer, xanthan gum retarded release over 24 h and the Higuchi model best fit the data. When mixed with guar gum, at 10% or 20% xanthan levels, xanthan gum was unable to control release. However, tablets containing 30% guar gum and 30% xanthan gum behaved as if xanthan gum was the sole rate-retarding gum and drug was released by Fickian diffusion. Release profiles from certain tablets match 12-h literature profiles and the 24-h profile of Inderal(®) LA. The results confirm that guar gum, xanthan gum, and HPMC can be used for the successful preparation of sustained release oral propranolol hydrochoride tablets.

  8. Efeito de diferentes tipos de fibras sobre frações lipídicas do sangue e fígado de ratos wistar

    OpenAIRE

    Eufrásio,Moacir Robson; Barcelos,Maria de Fátima Piccolo; Sousa,Raimundo Vicente de; Abreu,Wilson César de; Lima,Maria Aparecida Correa; Pereira, Michel Cardoso de Angelis

    2009-01-01

    Conduziu-se o presente estudo, com o objetivo de avaliar o efeito de diferentes tipos de fibras sobre as fraçoes lipídicas do sangue e fígado de ratos. Para determinar o efeito da pectina citrica, goma guar e celulose sobre o perfil lipidico dos ratos utilizaramse 36 ratos machos da linhagem wistar. Os ratos foram distribuidos aleatoreamente em seis grupos. Cada gruopo foi submetido a uma dieta por 58 dias. As dietas utilizadas foram: A- 10% de pectina, B - 15% de pectina, C - 10% de goma gua...

  9. EFFECT OF ANIONIC SURFACTANT UPON THE VISCOSITY OF POLYMER GUAR GUM SOLUTIONS

    Institute of Scientific and Technical Information of China (English)

    Xiao-ming Chen; Hai-yang Yang; Xian You; Ping-ping Zhu; Ping-sheng Hea

    2006-01-01

    The reduced viscosity of polymer guar gum solutions containing a certain concentration of sodium dodecyl benzene sulfonate (SDBS) was measured. It has been found that the Huggins coefficient kH of polymer solutions is verysensitive to the concentration of the surfactant, cSDBS, in solutions. If cSDBS is lower than CMC, the critical micelle concentration of SDBS, kH increases rapidly with cSDBS. On the other hand, if cSDBS is larger than CMC, kH decreases rapidly with cSDBS. Comparatively, the intrinsic viscosity of polymer solution does not show a notable change with cSDBS. The experimental results indicate that the interchain association of polymer guar gum in solution is greatly associated with SDBS interacted with polymer chains through hydrogen bonds. However, the effect of SDBS upon the intrachain association of polymer guar gum solution is negligible, presumably due to the fact that guar gum is a slightly stiffened random-coil chain polymer.

  10. Effect of partially hydrolyzed guar gum (PHGG) on the bioaccessibility of fat and cholesterol

    NARCIS (Netherlands)

    Minekus, M.; Jelier, M.; Xiao, J.-Z.; Kondo, S.; Iwatsuki, K.; Kokubo, S.; Bos, M.; Dunnewind, B.; Havenaar, R.

    2005-01-01

    The Addition of a compound that lowers the intestinal uptake of fat and cholesterol might be an interesting strategy to reduce the risk of vascular disease. Partially hydrolyzed guar gum (PHGG) has been shown to have this effect in healthy volunteers after intake of a yogurt drink with 3 to 6% PHGG.

  11. Effect of feeding guar meal on nutrient utilization and growth performance in Mahbubnagar local kids

    Directory of Open Access Journals (Sweden)

    Razia Sultana Janampet

    2016-10-01

    Full Text Available Aim: This study was conducted to evaluate the growth performance and nutrient digestibility of guar meal, an unconventional protein-rich feed ingredient in kids in comparison to conventional groundnut cake. Materials and Methods: A total of 18 kids were randomly allotted to three groups, and T1 group was fed on basal diet, T2 and T3 groups were offered diet replacing groundnut cake at 50% and 100% with guar meal, respectively, for a period of 120-day. At the end of the growth trial, a digestibility trial was conducted to evaluate the nutrient utilization. Results: There was no significant difference in dry matter intake among three groups. Nutrient digestibilities were significantly higher (p<0.05 in kids fed T2 ration with 50% replacement of groundnut cake with guar meal. Conclusion: It can be concluded that guar meal can be incorporated at 50% level in the concentrate mixture of goats replacing groundnut cake without any adverse effects.

  12. Colon Targeted Guar Gum Compression Coated Tablets of Flurbiprofen: Formulation, Development, and Pharmacokinetics

    Directory of Open Access Journals (Sweden)

    Sateesh Kumar Vemula

    2013-01-01

    Full Text Available The rationale of the present study is to formulate flurbiprofen colon targeted compression coated tablets using guar gum to improve the therapeutic efficacy by increasing drug levels in colon, and also to reduce the side effects in upper gastrointestinal tract. Direct compression method was used to prepare flurbiprofen core tablets, and they were compression coated with guar gum. Then the tablets were optimized with the support of in vitro dissolution studies, and further it was proved by pharmacokinetic studies. The optimized formulation (F4 showed almost complete drug release in the colon (99.86% within 24 h without drug loss in the initial lag period of 5 h (only 6.84% drug release was observed during this period. The pharmacokinetic estimations proved the capability of guar gum compression coated tablets to achieve colon targeting. The Cmax of colon targeted tablets was 11956.15 ng/mL at Tmax of 10 h whereas it was 15677.52 ng/mL at 3 h in case of immediate release tablets. The area under the curve for the immediate release and compression coated tablets was 40385.78 and 78214.50 ng-h/mL and the mean resident time was 3.49 and 10.78 h, respectively. In conclusion, formulation of guar gum compression coated tablets was appropriate for colon targeting of flurbiprofen.

  13. Enhanced transport of zerovalent iron nanoparticles in saturated porous media by guar gum

    Energy Technology Data Exchange (ETDEWEB)

    Tiraferri, Alberto; Sethi, Rajandrea, E-mail: rajandrea.sethi@polito.i [Politecnico di Torino, DITAG - Dipartimento di Ingegneria del Territorio, dell' Ambiente e delle Geotecnologie (Italy)

    2009-04-15

    In order to ensure adequate mobility of zerovalent iron nanoparticles in natural aquifers, the use of a stabilizing agent is necessary. Polymers adsorbed on the nanoparticle surface will give rise to electrosteric stabilization and will decrease attachment to the surface soil grains. Water saturated sand-packed columns were used in this study to investigate the transport of iron nanoparticle suspensions, bare or modified with the green polymer guar gum. The suspensions were prepared at 154 mg/L particle concentration and 0.5 g/L polymer concentration. Transport experiments were conducted by varying the ionic strength, ionic composition, and approach velocity of the fluid. Nanoparticle deposition rates, attachment efficiencies, and travel distances were subsequently calculated based on the classical particle filtration theory. It was found that bare iron nanoparticles are basically immobile in sandy porous media. In contrast, guar gum is able to ensure significant nanoparticle transport at the tested conditions, regardless of the chemistry of the solution. Attachment efficiency values for guar gum-coated nanoparticles under the various conditions tested were smaller than 0.066. Although the calculated travel distances may not prove satisfactory for field application, the investigation attested the promising role of guar gum to ensure mobility of iron nanoparticles in the subsurface environment.

  14. Colon targeted guar gum compression coated tablets of flurbiprofen: formulation, development, and pharmacokinetics.

    Science.gov (United States)

    Vemula, Sateesh Kumar; Bontha, Vijaya Kumar

    2013-01-01

    The rationale of the present study is to formulate flurbiprofen colon targeted compression coated tablets using guar gum to improve the therapeutic efficacy by increasing drug levels in colon, and also to reduce the side effects in upper gastrointestinal tract. Direct compression method was used to prepare flurbiprofen core tablets, and they were compression coated with guar gum. Then the tablets were optimized with the support of in vitro dissolution studies, and further it was proved by pharmacokinetic studies. The optimized formulation (F4) showed almost complete drug release in the colon (99.86%) within 24 h without drug loss in the initial lag period of 5 h (only 6.84% drug release was observed during this period). The pharmacokinetic estimations proved the capability of guar gum compression coated tablets to achieve colon targeting. The C(max) of colon targeted tablets was 11956.15 ng/mL at T max of 10 h whereas it was 15677.52 ng/mL at 3 h in case of immediate release tablets. The area under the curve for the immediate release and compression coated tablets was 40385.78 and 78214.50 ng-h/mL and the mean resident time was 3.49 and 10.78 h, respectively. In conclusion, formulation of guar gum compression coated tablets was appropriate for colon targeting of flurbiprofen.

  15. Linear viscoelastic behavior of enzymatically modified guar gum solutions: structure, relaxations and gel formation

    NARCIS (Netherlands)

    Wientjes, R.H.W.; Duits, M.H.G.; Bakker, J.W.P.; Jongschaap, R.J.J.; Mellema, J.

    2001-01-01

    To gain more insight into the mechanisms of stress relaxation in aqueous guar gum solutions, we investigated the effect of chemical modifications of the polymer and of the solvent on the linear viscoelastic behavior in different regions of the frequency domain. Interchain bonding could be ruled out

  16. Enhanced transport of zerovalent iron nanoparticles in saturated porous media by guar gum

    Science.gov (United States)

    Tiraferri, Alberto; Sethi, Rajandrea

    2009-04-01

    In order to ensure adequate mobility of zerovalent iron nanoparticles in natural aquifers, the use of a stabilizing agent is necessary. Polymers adsorbed on the nanoparticle surface will give rise to electrosteric stabilization and will decrease attachment to the surface soil grains. Water saturated sand-packed columns were used in this study to investigate the transport of iron nanoparticle suspensions, bare or modified with the green polymer guar gum. The suspensions were prepared at 154 mg/L particle concentration and 0.5 g/L polymer concentration. Transport experiments were conducted by varying the ionic strength, ionic composition, and approach velocity of the fluid. Nanoparticle deposition rates, attachment efficiencies, and travel distances were subsequently calculated based on the classical particle filtration theory. It was found that bare iron nanoparticles are basically immobile in sandy porous media. In contrast, guar gum is able to ensure significant nanoparticle transport at the tested conditions, regardless of the chemistry of the solution. Attachment efficiency values for guar gum-coated nanoparticles under the various conditions tested were smaller than 0.066. Although the calculated travel distances may not prove satisfactory for field application, the investigation attested the promising role of guar gum to ensure mobility of iron nanoparticles in the subsurface environment.

  17. Graft (partially carboxymethylated guar gum-g-poly vinyl sulfonic acid) copolymer: from synthesis to applications.

    Science.gov (United States)

    Yadav, Mithilesh; Srivastav, Abhishek; Verma, Shiv Kumar; Behari, Kunj

    2013-09-12

    The aim of the paper is to study the physico-chemical phenomenon of synthesized graft copolymer (carboxymethylated guar gum-g-vinylsulfonic acid). The reaction optimum conditions for grafting has also been determined by studying the effect of vinylsulfonic acid, hydrogen ion, peroxymonosulphate, glycolic acid concentration and carboxymethylated guar gum along with time and temperature. Experimental results show that maximum grafting has been obtained at 1.8 g dm(-3) concentration of partially carboxymethylated guar gum and 5.3 × 10(-2) mol dm(-3) concentration of vinylsulfonic acid. It has been observed that grafting ratio, add on, conversion, efficiency increase up to 4.0 × 10(-3) mol dm(-3) of hydrogen ion, 4 × 10(-3) mol dm(-3) of glycolic acid, 14 × 10(-3) mol dm(-3) of peroxymonosulphate and 35 °C of temperature. Grafted copolymer has been characterized by FTIR spectroscopy and thermogravimetric analysis. Water swelling, flocculating, metal ion uptake and resistance to biodegradability properties of partially carboxymethylated guar gum-g-vinylsulfonic acid have been determined.

  18. Ronidazole pharmacokinetics in cats following delivery of a delayed-release guar gum formulation.

    Science.gov (United States)

    Papich, M G; Levine, D N; Gookin, J L; Davidson, G S; Stagner, W C; Hayes, R B

    2013-08-01

    Ronidazole (RDZ) is the only known effective treatment for feline diarrhea caused by Tritrichomonas foetus. This study aimed to develop guar gum-coated colon-targeted tablets of RDZ and to determine the pharmacokinetics of this delayed-release formulation in cats. Guar gum-coated tablets were administered orally once to five healthy cats (mean dose 32.3 mg/kg). The tablets were then administered once daily for 5 days to four cats (mean dose 34.5 mg/kg), and absorption studies repeated on day 5. Plasma was collected and analyzed for RDZ concentration, and pharmacokinetic noncompartmental and deconvolution analysis were performed on the data. There was negligible RDZ release until after 6 h, and a delayed peak plasma concentration (mean Cmax 28.9 μg/mL) at approximately 14.5 h, which coincides with colonic arrival in cats. Maximum input rate (mg/kg per hour) occurred between 6 and 16 h. This delayed release of ronidazole from guar gum-coated tablets indicates that release of RDZ may be delayed to deliver the medication to a targeted area of the intestine. Repeated dosing with guar gum tablets to steady-state did not inhibit drug bioavailability or alter the pharmacokinetics. Such targeted RDZ drug delivery may provide improved efficacy and reduce adverse effects in cats.

  19. Graft polymerization of guar gum with acryl amide irradiated by microwaves for colonic drug delivery.

    Science.gov (United States)

    Shahid, Muhammad; Bukhari, Shazia Anwer; Gul, Yousra; Munir, Hira; Anjum, Fozia; Zuber, Mohammad; Jamil, Tahir; Zia, Khalid Mahmood

    2013-11-01

    This article is aimed to discuss the modification of guar gum through microwave irradiation by varying the time of irradiation. The characterization of the modified products was carried out using FTIR spectroscopic analysis. The FT-IR spectrum of the pure guar gum (GG) sample showed a broad peak at 3298 cm(-1) while the modified GG sample displayed a peak at 1541 cm(-1) which was absent in the crude sample. The X-ray diffraction (XRD) analysis confirmed the increase in crystallinity due to grafting of the sample with polyacrylamide (GG-g-PAM). Scanning electron microscope (SEM) images revealed that granular form of guar gum was changed into fibrillar structure after grafting. Thermo-gravimetric analysis of the modified samples was also carried out and discussed. The role of guar gum as a matrix for controlled release of drug triamcinolone was evaluated. The GG-acrylamide grafted samples presented a correlation between drug release and time of microwave exposure. The results revealed that such modified product has potential applications in colonic drug delivery system.

  20. Efek Penambahan -Galaktosidase Famili 27 Glikosida Hidrolase Bacillus Halodurans terhadap Kekentalan Guar Gum

    Directory of Open Access Journals (Sweden)

    Andian Ari Anggraeni

    2008-10-01

    Full Text Available Penelitian ini bertujuan untuk mempelajari aktivitas protein hasil translasi gen a-galaktosidase dari Bacillus halodurans famili 27 glikosida hidrolase dengan cara mengamati pengaruh penambahan protein terhadap kekentalan larutan guar gum. Penelitian ini dilakukan dengan menggunakan metode eksperimen. a-Galaktosidase adalah enzim yang mengkatalisasi hidrolisis ikatan a-1,6-galaktosida dari terminal non-reducing pada oligosakarida, liposakarida dan/atau polisakarida yang mengandung galaktosa. Protein rekombinan yang diekspresikan oleh gen  agalaktosidase BH1870 Bacillus halodurans dipurifikasi menggunakan His-binding metal affinity chromatography. Uji aktivitas dilakukan dengan menggunakan substrat guar gum pada beberapa interval suhu, yaitu 37, 45, 55 dan 65o C. Enzim ini mampu menghidrolisa guar gum pada suhu 37 oC, yang ditunjukkan dengan penurunan kekentalan larutan guar gum.  Namun, enzim ini tidak stabil pada suhu yang lebih besar dari 37 oC. Beberapa residu asam amino yang dianggap penting bagi aktivitas hidrolisis enzim famili 27 ternyata tidak terdapat pada B. halodurans a-galaktosidase. Ketiadaan residu ini mungkin dapat mempengaruhi kestabilan enzim pada suhu tinggi. Untuk membuktikan asumsi ini, diperlukan studi lanjut tentang site-directed mutagenesis pada residu-residu ini.

  1. Growth and Yield Performance of Five Guar Cultivars in a Mediterranean Environment

    Directory of Open Access Journals (Sweden)

    Orazio Sortino

    2007-12-01

    Full Text Available In order to evaluate growth and yield performance of guar (Cyamopsis tetragonoloba L. in Mediterranean area, main morphological parameters (plant height, dry weight of single plant parts, branch and leaf number, dry biomass accumulation and seed yield response of five varieties of guar (Esser, Malosan, Kinman, Lewis and Santa Cruz were studied. Seed crude protein and fibre content were also determined. Irrigation was applied to ensure that water availability did not limit production. The growing season of guar lasted for 120 days for all the varieties. Average plant height at harvest was about 63 cm (ranging from 56.0 to 70.6 cm. The highest dry weight increment was recorded during 55-70 days after sowing. Malosan, Santa Cruz and Kinman showed the highest individual seed weight (> 30 mg. Above average leaf and branch number were observed in Kinman, Esser and Santa Cruz. The greatest seed protein content was observed in Lewis and Esser (35.6% and 34.7%. High yield and seed quality were obtained in these environments with limited water supply, indicating that guar may represent a valid alternative multipurpose crop for semiarid regions.

  2. Extensional flow behavior of aqueous guar gum derivative solutions by capillary breakup elongational rheometry (CaBER).

    Science.gov (United States)

    Szopinski, Daniel; Handge, Ulrich A; Kulicke, Werner-Michael; Abetz, Volker; Luinstra, Gerrit A

    2016-01-20

    The extensional rheological properties of aqueous ionic carboxymethyl hydroxypropyl guar gum (CMHPG) and non-ionic hydroxypropyl guar gum (HPG) solutions between the semi-dilute solution state and the concentrated network solution state were investigated by capillary breakup elongational rheometry (CaBER). Carboxymethylated guar gum derivatives show an instable filament formation in deionized water. The ratio of elongational relaxation time λE over the shear relaxation time λS follows a power law of λE/λS∼(c · [η])(-2). The difference of the relaxation times in shear and elongation can be related to the loss of entanglements and superstructures in elongational flows at higher strains.

  3. The human health impact of Nyiragongo and Nyamulagira eruptions on Goma city and its surrounding area

    Science.gov (United States)

    Michellier, C.; Dramaix, M.; Arellano, S. R.; Kervyn, F.; Kahindo, J. B.

    2012-04-01

    Located in the east of the Democratic Republic of Congo (DRC), Nyiragongo and Nyamulagira are two of the most active volcanoes in Africa. Nyiragongo last erupted in January 2002 and Nyamulagira in November 2011. Even if only a small number of victims resulted directly from these eruptions (notably because they both happened in the day-time), the town of Goma (approx. 700 000 inhabitants) is directly threatened by the fluid lava flows, of which the speed can reach several tens of km/h. But this is not the only menace. Indeed, Nyiragongo hosts a permanent lava lake that produces a plume of gases rich in sulphur (SO2), carbon (CO2), and halogen compounds (HCl, HF). As for Nyamulagira, it makes a major contribution to these emissions during its frequent and regular periods of eruptive activity (approx. every two years). Although the region under study is densely populated (up to 250 inh/km2), and basic volcanic hazard mapping exists, an updated and long-term evaluation of the specific impact of Nyiragongo and Nyamulagira semi-permanent volcanic plumes on the population health has not been done to date. It is the objective of this study. Michigan Technological University (MTU, USA) provides satellite data retrievals of volcanogenic SO2 gas columns. These remote sensing data provide insights about the spatial distribution of Nyiragongo and Nyamulagira plumes, which are used to select the sampling areas for studying the human health impact of volcanic emissions. Based on the Congolese Health Information System (HIS) data provided by the CEMUBAC, our study is focused on the 1999-2010 time period. Scientific studies carried out on other active volcanoes suggest that certain pathologies could be linked to a high concentration of SO2 in the atmosphere. These include Acute Respiratory Infections (ARI), conjunctivitis, skin diseases, and ear-nose-throat infections. Using Poisson regression analysis, we determine a Relative Risk Index (IRR) that allows us to identify the years

  4. Synthesis, characterization and evaluation of the antioxidant potential of vanadium encapsulated guar gum nanoparticles.

    Science.gov (United States)

    Soumya, R S; Reshmi, R; Jomon, S; Antu, K A; Riya, M P; Raghu, K G

    2014-03-01

    The present study investigated the antioxidant potential of guar gum macroparticles (GGMs), vanadium oxide sulphate (VS) encapsulated guar gum macroparticles (GVMs), guar gum nanoparticles (GGNs), VS encapsulated guar gum nanoparticles (GVNs) and VS. GGNs and GVNs prepared by nanoprecipitation were characterized by SEM (scanning electron microscopy), TEM (transmission electron microscopy) and particle size analysis to confirm the nanostructure of the particles. Particle size analysis revealed that GVNs possess a size of 239 nm, about 148 nm larger than that of GGNs. TEM imaging and EDAX data also confirmed the formation of fine spherical nanoparticles with vanadium incorporation. In addition the larger size of GVNs also confirmed the vanadium incorporation. MTT assay showed that concentrations up to 100 nM of GVNs for 24 h exposure did not induce significant toxicity when VS was toxic (16%) at 100 nM. Various in vitro antioxidant assays (total reducing power, total antioxidant capacity, DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid), hydroxyl radical and superoxide anion radical scavenging assays) revealed significantly high antioxidant potential of GVNs compared to GGNs, VS, GGMs and GVMs. The IC50 of GVNs was 23.21 ± 2.1 μg mL(-1), 33.0 ± 2.93 μg mL(-1), 21 ± 1.98 μg mL(-1) and 22.79 ± 2.12 μg mL(-1) for DPPH, ABTS, hydroxyl, superoxide anion scavenging activity assays respectively. The cell line based assay also proved that the GVN was more effective in reactive oxygen species (ROS) scavenging than VS against tertiary butyl hydrogen peroxide (TBHP) induced oxidative stress in H9c2 cell lines. The overall results indicated that vanadium in combination with nano guar gum exhibits significantly high antioxidant potential.

  5. Freeze-dried Xanthan/Guar Gum Nasal Inserts for the Delivery of Metoclopramide Hydrochloride.

    Science.gov (United States)

    Dehghan, Mohamed Hassan; Girase, Mohan

    2012-01-01

    Prolonged residence of drug formulation in the nasal cavity is important for the enhancing intranasal drug delivery. The objective of the present study was to develop a mucoadhesive in-situ gelling nasal insert which would enable the reduced nasal mucociliary clearance in order to improve the bioavailability of metoclopramide hydrochloride. Metoclopramide hydrochloride is a potent antiemetic and effective for preventing emesis induced by cancer chemotherapy, migraine, pregnancy and gastroparesis. It undergoes hepatic first pass metabolism and both the absolute bioavailability and the plasma concentrations are subjected to wide inter-individual variation showing values between 32% and 98%. Oral antiemetic often gets vomited out before the systemic absorption compelling parenteral administration which results in low patient compliance. Adverse effect of metoclopramide HCL on CNS caused by high plasma peaks can be avoided through sustained formulation. A novel combination of xanthan gum and guar gum was used to prepare the nasal inserts and the effect of blend ratio of xanthan gum and guar gum on drug release from in-situ gelling nasal inserts and on other insert properties such as bioadhesion potential and water uptake was studied. PXRD was used to determine the effect of freeze-drying on crystalline nature of formulation. The viscosities of xanthan gum in combination with guar gum were observed to be higher than that of single polymer solutions. This is because of the synergistic rheological interaction between xanthan and guar gum. There is a substantial loss in crystalline nature of the formulation after freeze-drying. The best nasal inserts formulation containing xanthan gum and guar gum ratio 1:5, showed good release (91.83%) as well as bioadhesion which may result in an increase in the nasal residence time.

  6. Collagen-poly(dialdehyde) guar gum based porous 3D scaffolds immobilized with growth factor for tissue engineering applications.

    Science.gov (United States)

    Ragothaman, Murali; Palanisamy, Thanikaivelan; Kalirajan, Cheirmadurai

    2014-12-19

    Here we report the preparation of collagen-poly(dialdehyde) guar gum based hybrid functionalized scaffolds covalently immobilized with platelet derived growth factor - BB for tissue engineering applications. Poly(dialdehyde) guar gum was synthesized from selective oxidation of guar gum using sodium periodate. The synthesized poly(dialdehyde) guar gum not only promotes crosslinking of collagen but also immobilizes the platelet derived growth factor through imine bonds. The covalent crosslinking formed in collagen improves thermal, swelling and biodegradation properties of the hybrid scaffolds. The prepared hybrid scaffolds show 3D interconnected honeycomb porous structure when viewed under a microscope. The release of immobilized platelet derived growth factor was seen up to 13th day of incubation thereby proving its sustained delivery. The developed hybrid scaffold leads to a quantum increase in NIH 3T3 fibroblast cell density and proliferation thereby demonstrating its potential for tissue engineering applications.

  7. Influência de hidrocolóides na textura de gel de amido de milho Influence of hydrocolloids in texture of corn starch gel

    Directory of Open Access Journals (Sweden)

    Maisa Peixoto Munhoz

    2004-09-01

    Full Text Available O presente trabalho tem como objetivo determinar a influência das interações das gomas xantana e guar com o amido de milho de alto teor de amilose na textura de gel durante o armazenamento. Foram utilizadas amostras de amido milho Hylon VII® (71% de amilose, National Starch, goma guar (Higum 55I®, Rhodia e goma xantana (Rhodigel 200®, Rhodia. Foram utilizadas diferentes concentrações das gomas guar e xantana, que variaram de 0 a 1%, de acordo com o delineamento experimental central composto rotacional. Em cada tratamento foram utilizadas 50g de amido com alto teor de amilose (Hylon VII, adicionadas das gomas. Estas amostras foram diluídas em água destilada e submetidas à agitação mecânica até completa dissolução. As soluções foram aquecidas até 95°C por 5 minutos para formação dos géis, os quais foram acondicionados em recipientes plásticos de 50mL e mantidos em temperatura de 5-10°C até 120h. Nos tempos T1 (24h, T2 (48h, T3 (72h, T4 (96h e T5 (120h de armazenamento foram feitas medidas da força máxima do gel de amilose em texturômetro (Stable Micro-System, Modelo TAX-T2. No período inicial, de 24 horas, a goma guar não apresentou influência positiva na redução da força do gel, sendo que a aplicação de goma xantana entre 0,7 e 1,0% apresentou os menores valores de força do gel de amilose. Após 120h de armazenamento, a força do gel de amilose diminuiu com a adição de 0,5-1,0% de goma xantana e 0-0,15% de goma guar.The main objective of this study was to determine the influence of the interactions between guar and xanthan gums with high amylose content corn starch on the texture of the gel during storage. The samples used were Hylon VII® corn starch (71% amylose (National Starch, Guar gum (Higum 551®, Rhodia and Xanthan gum (Rhodigel 200®, Rhodia. A central composite rotational design was used to formulate gels with different concentrations of the guar and xanthan gums, from 0 to 1%. For each treatment

  8. Preparation and in vitro evaluation of guar gum based triple-layer matrix tablet of diclofenac sodium

    OpenAIRE

    Chavda, H. V.; M. S. Patel; Patel, C N

    2012-01-01

    The objective of the present study was to design an oral controlled drug delivery system for sparingly soluble diclofenac sodium (DCL) using guar gum as triple-layer matrix tablets. Matrix tablet granules containing 30% (D1), 40% (D2) or 50% (D3) of guar gum were prepared by the conventional wet granulation technique. Matrix tablets of diclofenac sodium were prepared by compressing three layers one by one. Centre layer of sandwich like structure was incorporated with matrix granules containin...

  9. Effect of incorporation of pumpkin (Cucurbita moshchata) powder and guar gum on the rheological properties of wheat flour

    OpenAIRE

    Kundu, Himani; Grewal, Raj Bala; Goyal, Ankit; Upadhyay, Neelam; Prakash, Saurabh

    2012-01-01

    The present study was carried out to study the effect of incorporation of fibre rich pumpkin powder and guar gum on the farinographic characteristics of wheat flour. The flour and pumpkin powder were assessed for proximate composition, total dietary fibre, minerals and β-carotene. Pumpkin powder contained appreciable amount of fibre, minerals and β-carotene. The effects of incorporation of different levels of pumpkin powder and guar gum along with pumpkin powder on farinographic characteristi...

  10. Avaliação do perfil eletrocardiográfico pré e trans-anestesia em lobos-guará

    Directory of Open Access Journals (Sweden)

    W.O. Dias

    2015-12-01

    Full Text Available O presente estudo tem como objetivo avaliar o efeito da administração do Zolazepam/Tiletamina nas funções cardiorrespiratórias e eletrocardiográficas em lobos-guará (Chrysocyon brachyurus mantidos em cativeiro. Foram utilizados dez lobos-guará clinicamente saudáveis (seis machos e quatro fêmeas, com média de peso 23,5±3,5kg, e idade de 6,5±2,8 anos. Os lobos eram mantidos em cativeiro e foram capturados pelos tratadores, proporcionando o mínimo de estresse possível para avaliação dos parâmetros pré-anestésicos. Foram avaliadas frequência cardíaca e respiratória, temperatura retal, pressão arterial média e eletrocardiografia. Após coleta dos parâmetros fisiológicos e eletrocardiográficos pré-anestesia, foi administrada a dose de 5,1±0,7mg/kg de Zolazepam/Tiletamina intramuscular. Depois da anestesia, colocaram-se os eletrodos do eletrocardiograma nos membros torácicos e pélvicos. Os animais eram monitorados durante uma hora, sendo que, a cada 10 minutos, era realizado o registro dos valores eletrocardiográficos, assim como os valores dos parâmetros fisiológicos e cardiorrespiratórios. Os resultados mostraram alteração significativa na amplitude da onda P entre 10 a 50 minutos pós-anestesia. Frequência cardíaca (153±20bmp, frequência respiratória (29±6mpm, temperatura corporal (38,4±1oC, pressão arterial média (114±20mmHg e as outras variáveis eletrocardiográficas não apresentaram alterações. O aumento da amplitude da onda P nos animais deste trabalho sugeriu um aumento atrial, oriundo de doenças cardíacas ou simplesmente pelo aumento da frequência cardíaca durante a contenção.

  11. Caracterização por espectroscopia vibracional de filmes Layer-by-Layer contendo ftalocianina, polímeros condutores e gomas naturais

    OpenAIRE

    Kitagawa, Igor Lebedenco [UNESP

    2009-01-01

    Esta dissertação apresenta o estudo do crescimento (em escala nanométrica) e morfológica (em escala micrométrica) de filmes finos fabricados segundo a técnica Layer-by-Layer (LbL) contendo ftalocianina tetrasulfonada de níquel, polímeros condutores, o polímero poli(alilamina hidroclorada) (PAH), e gomas naturais. Três sistemas foram investigados: i) filmes LbL de NiTsPc e PAH; ii) filme LbL de NiTsPc, PAH e gomas naturais e iii) filmes LbL dos polímeros condutores polianilina (PANI) e poli(o-...

  12. [Study on the selective removal of plasma low-density lipoprotein and fibrinogen by degraded guar sulfate].

    Science.gov (United States)

    Zhu, Ye; Fang, Bo; Huang, Li; Guan, Chen; Yang, Guang

    2008-10-01

    Degraded guar was prepared by acid with guar as the main material, which was then brought into reaction with chlorosulfonic acid under proper conditions, the sulfonated degraded guar was obtained successfully. The effects of sulfonation conditions on the SO4(2-) content were investigated, and the proper reaction conditions were determined. The results of infrared spectrometry showed that this sulfated derivative is a novel heparin-like polysaccharide. At the same time, the selective removal of low density lipoprotein (LDL) and fibrinogen (Fib) by degraded guar gum sulfate was studied. The experimental results showed that degraded guar gum sulfate is a novel LDL/ Fib purifying agent. When pH= 5.15 and the initial concentration of the degraded guar gum sulfate is 2500 mg/L, the reduction percentages were about 60%-66% for total cholesterol, about 76%-89% for LDL and very low-density lipoproteins (VLDL), and almost 100% for fibrinogen. There were no significant changes regarding the level of high-density lipoproteins and total proteins.

  13. Effect of nano-alumina concentration on the mechanical, rheological, barrier and morphological properties of guar gum.

    Science.gov (United States)

    Savvashe, Prashant; Kadam, Pravin; Mhaske, Shashank

    2016-04-01

    In this work, nano-alumina was utilized as a reinforcing agent for guar gum, with an aim to improve its performance properties; especially, mechanical and barrier i.e. water vapor transmission rate (WVTR). Films were prepared by the process of solution casting. Concentration of nano-alumina was varied as 0, 1, 3, 5 and 7 parts per hundred parts of resin (phr) in guar gum. The prepared pristine and guar gum/alumina nano-composite films were characterized for mechanical, puncture, x-ray diffraction, barrier, rheological and morphological properties. Tensile strength, Young's modulus, puncture strength, viscosity and crystallinity increased; whereas, WVTR, elongation at break (%) and damping factor decreased with increased concentration of nano-alumina in guar gum. However, optimized improvement in the performance properties were determined for 5 phr nano-alumina loaded guar gum polymer matrix, attributed to its better dispersion and interaction into the guar gum polymer chains due to the hydrophilic nature of both the materials. Above 5 phr concentration nano-alumina started forming aggregates, as evident from scanning electron microscopy.

  14. Prevalence and associated factors of partially/non-immunization of under-five in Goma city, Democratic Republic of Congo: a community-based cross-sectional survey

    Science.gov (United States)

    Kabudi, André Mwanishayi; Lutala, Prosper Mukobelwa; Kazadi, Junior Mulaja; Bardella, Inis Jane

    2015-01-01

    Introduction At the East part of DRC, anecdotal reports are advancing several causes of unsuccessful campaigns of vaccination by the time going: rumors about use of vaccines for killing purpose, injection of vaccine to decrease the reproductive potential in coming generations, use of vaccines by some rebellions and neighboring countries to kill children indirectly, ineffectiveness of vaccines currently on the market. While those rumors seem to be less reliable, potential beneficiaries are taking them seriously and justifying a reluctance to bring their children or siblings for immunization. Against this above background, our community Primary Health Care team indicates that still, in Goma city in general and even in the referral hospital catchment area, there are children who have never been vaccinated. Objectives To determine the prevalence and determinants of non-immunization of under-five children in Goma City. Study design Cross-sectional community-based survey. Methods A sample size of 384 children aged under-five years from the target population was used for the study. The ratio of under-five years of age Goma city to the total population of Goma city for the year 2012 was considered as the study population frame. Results The prevalence of under-five non-immunized children was 25.7%. There was an association between immunization status of children and their gender, school characteristics, age, sibling, the level of literacy, the marital status of their parents and the age of their mothers. Conclusion For improving the quality of under-five children immunization, the medical authorities must consider these different determinants. PMID:26029327

  15. Radiation-induced grafting of acrylamide onto guar gum in aqueous medium: Synthesis and characterization of grafted polymer guar-g-acrylamide

    Science.gov (United States)

    Biswal, Jayashree; Kumar, Virendra; Bhardwaj, Y. K.; Goel, N. K.; Dubey, K. A.; Chaudhari, C. V.; Sabharwal, S.

    2007-10-01

    Mutual radiation grafting technique has been applied to carry out grafting of acrylamide (AAm) onto guar gum (GG) using high-energy Co 60γ radiation to enhance its flocculating properties for industrial effluents. The grafted product was characterized using analytical probes like elemental analysis, thermal analysis, Fourier transformed infrared (FTIR), X-ray diffraction (XRD) and scanning electron microscope (SEM). The grafting extent was observed to decrease with the dose rate and increase with the concentration of AAm. Thermo gravimetric analysis (TGA) of grafted and ungrafted samples indicated better stability of grafted product. γ and microwave radiation effect on grafted and virgin GG has also been reported.

  16. Radiation-induced grafting of acrylamide onto guar gum in aqueous medium: Synthesis and characterization of grafted polymer guar-g-acrylamide

    Energy Technology Data Exchange (ETDEWEB)

    Biswal, Jayashree [Radiation Technology Development Section, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085 (India); Kumar, Virendra [Radiation Technology Development Section, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085 (India); Bhardwaj, Y.K. [Radiation Technology Development Section, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085 (India)]. E-mail: ykbhard@magnum.barc.ernet.in; Goel, N.K. [Radiation Technology Development Section, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085 (India); Dubey, K.A. [Radiation Technology Development Section, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085 (India); Chaudhari, C.V. [Radiation Technology Development Section, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085 (India); Sabharwal, S. [Radiation Technology Development Section, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085 (India)

    2007-10-15

    Mutual radiation grafting technique has been applied to carry out grafting of acrylamide (AAm) onto guar gum (GG) using high-energy Co{sup 60} {gamma} radiation to enhance its flocculating properties for industrial effluents. The grafted product was characterized using analytical probes like elemental analysis, thermal analysis, Fourier transformed infrared (FTIR), X-ray diffraction (XRD) and scanning electron microscope (SEM). The grafting extent was observed to decrease with the dose rate and increase with the concentration of AAm. Thermo gravimetric analysis (TGA) of grafted and ungrafted samples indicated better stability of grafted product. {gamma} and microwave radiation effect on grafted and virgin GG has also been reported.

  17. Stretching properties of xanthan, carob, modified guar and celluloses in cosmetic emulsions.

    Science.gov (United States)

    Gilbert, Laura; Loisel, Vincent; Savary, Géraldine; Grisel, Michel; Picard, Céline

    2013-04-02

    The filament stretching properties of various polysaccharides (including xanthan, carob, hydroxypropyl guar, hydroxypropylmethyl and hydroxyethyl celluloses) were investigated and compared to synthetic polymers generally used as texturing agents in cosmetic emulsions. The stretchability was examined by sensory evaluation as "the amount of sample that strings rather than breaks when fingers are separated". Different behaviors were evidenced: the xanthan emulsion showed the highest stretchability, followed by the hydroxypropyl guar and hydroxyethyl cellulose emulsions while the synthetic polymers presented stretching properties to a much lesser extent. The instrumental characterization of the stretchability was conducted at a controlled speed and recorded with a camera using a texture analyzer. The maximum stretchable length at 40mm/s was highly significantly correlated to the sensory Stringiness, thus allowing a good predictability of this attribute. Finally, this method was applied to aqueous solutions to better understand the role of the polymers in emulsion and to validate the measurement on a wider range of products.

  18. Synergistic Interaction and Gelation in Cationic Guar Gum-Sodium Alginate System

    Institute of Scientific and Technical Information of China (English)

    He Dong-bao; Li Li-hua; Li Qing; Yang Xiao-zhen

    2004-01-01

    The synergistic interaction between the cationic guar gum (the ammonium hydroxy-propyl-trimethyl chloride of guar gum) and sodium alginate has been studied. The effects of the mass ratio of them, mixed temperature, balk salt ion concentration, incubation time and pH value on gelation were investigated. It has been observed that there was a gel strength maximum when the mass ratio was 0.6, the mixed temperature was 70℃, the balk salt ion concentration was 1.0 mol·L-1,the incubation time was 30 min and the pH value was 8. Interaction between molecules of these two polysaccharides was investigated by FT-IR spectrometry.

  19. Structure-property relationships of carboxymethyl hydroxypropyl guar gum in water and a hyperentanglement parameter.

    Science.gov (United States)

    Szopinski, Daniel; Kulicke, Werner-Michael; Luinstra, Gerrit A

    2015-03-30

    The viscoelastic properties of carboxymethyl hydroxypropyl guar gum (CMHPG) in aqueous solution were determined as function of concentration and of molecular weight, using SEC/MALLS/dRI and viscometry. The chain is more rigid as in native guar as was deduced from the molecular parameter in dilute solution. Superstructures are formed in moderately concentrated solutions as is shown from the comparison of steady state shear and small amplitude oscillatory shear (SAOS) experiments. The shear rate dependent viscosity of CMHPG can satisfactorily be described by the Carreau-Yasuda model with the rheological parameters (η0, λ0, n, b) obtained from the evaluation of viscosity data. A quantitative hyperentanglement parameter is introduced to account for the differences in responses in shear and SAOS experiments.

  20. High Temperature Stable Separator for Lithium Batteries Based on SiO₂ and Hydroxypropyl Guar Gum.

    Science.gov (United States)

    Carvalho, Diogo Vieira; Loeffler, Nicholas; Kim, Guk-Tae; Passerini, Stefano

    2015-10-23

    A novel membrane based on silicon dioxide (SiO₂) and hydroxypropyl guar gum (HPG) as binder is presented and tested as a separator for lithium-ion batteries. The separator is made with renewable and low cost materials and an environmentally friendly manufacturing processing using only water as solvent. The separator offers superior wettability and high electrolyte uptake due to the optimized porosity and the good affinity of SiO₂ and guar gum microstructure towards organic liquid electrolytes. Additionally, the separator shows high thermal stability and no dimensional-shrinkage at high temperatures due to the use of the ceramic filler and the thermally stable natural polymer. The electrochemical tests show the good electrochemical stability of the separator in a wide range of potential, as well as its outstanding cycle performance.

  1. Guar gum/borax hydrogel: Rheological, low field NMR and release characterizations

    Directory of Open Access Journals (Sweden)

    M. Grassi

    2013-09-01

    Full Text Available Guar gum (GG and Guar gum/borax (GGb hydrogels are studied by means of rheology, Low Field Nuclear Magnetic Resonance (LF NMR and model drug release tests. These three approaches are used to estimate the mesh size (ζ of the polymeric network. A comparison with similar Scleroglucan systems is carried out. In the case of GGb, the rheological and Low Field NMR estimations of ζ lead to comparable results, while the drug release approach seems to underestimate ζ. Such discrepancy is attributed to the viscous effect of some polymeric chains that, although bound to the network to one end, can freely fluctuate among meshes. The viscous drag exerted by these chains slows down drug diffusion through the polymeric network. A proof for this hypothesis is given by the case of Scleroglucan gel, where the viscous contribution is not so significant and a good agreement between the rheological and release test approaches was found.

  2. Radiation dose dependent change in physiochemical, mechanical and barrier properties of guar gum based films.

    Science.gov (United States)

    Saurabh, Chaturbhuj K; Gupta, Sumit; Bahadur, Jitendra; Mazumder, S; Variyar, Prasad S; Sharma, Arun

    2013-11-06

    Mechanical and water vapor barrier properties of biodegradable films prepared from radiation processed guar gum were investigated. Films prepared from GG irradiated up to 500 Gy demonstrated significantly higher tensile strength as compared to non-irradiated control films. This improvement in tensile strength observed was demonstrated to be due to the ordering of polymer structures as confirmed by small angle X-ray scattering analysis. Exposure to doses higher than 500 Gy, however, resulted in a dose dependent decrease in tensile strength. A dose dependent decrease in puncture strength with no significant differences in the percent elongation was also observed at all the doses studied. Water vapor barrier properties of films improved up to 15% due to radiation processing. Radiation processing at lower doses for improving mechanical and barrier properties of guar based packaging films is demonstrated here for the first time. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Synthesis of acrylate guar-gum for delivery of bio-active molecules

    Indian Academy of Sciences (India)

    Ajeet Kumar; Arnab De; Subho Mozumdar

    2015-08-01

    Modification of natural polymers by graft copolymerization is a promising technique as it functionalizes these biopolymer to their potential, imparting desirable properties onto them. Grafting with vinyl monomers is the route for modifying the properties of the naturally occurring guar-gum for their better industrial exploitation and development of various commercial products. Acrylated guar-gum chain is synthesized and analysed using Fourier transform infrared, differential scanning calorimetry and X-ray diffraction techniques to gain an insight into the particle size and structural features. Chlorpyrifos is then entrapped into the polymer, and its release is studied under various conditions. Critical factors influencing the size, entrapment efficiency and release behaviour of entrapped chlorpyrifos have been studied.

  4. Grafting of vinyl acetate-ethylacrylate binary monomer mixture onto guar gum.

    Science.gov (United States)

    Singh, Vandana; Singh, Angela; Joshi, Sneha; Malviya, Tulika

    2016-03-01

    Present article reports on guar gum (GG) functionalization through graftcopolymerization of vinylacetate (VAC) and ethylacrylate (EA) from their binary mixtures. The potassium persulfate/ascorbic acid (KPS/AA) redox initiator system has been used for the binary grafting under the previously optimized conditions for VAC grafting at guar gum. The concentration of ascorbic acid (AA), persulfate (KPS), and grafting temperature were varied to optimize the binary grafting. A preliminary investigation revealed that the copolymer has excellent ability to capture Hg(II) from aqueous solution. It was observed that the optimum % grafting sample (CP3) was best at Hg(II) adsorption. CP3 and mercury loaded CP3 (CP3-Hg) have been extensively characterized using Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), and Thermo gravimetric analysis (TGA) and a plausible mechanism for the grafting has been proposed.

  5. Removal of guar and humus from water by layered double hydroxides.

    Science.gov (United States)

    Jin, Song; Cui, Kangping; Fallgren, Paul H; Urynowicz, Michael A; Jian, Jiazhong

    2009-01-01

    Natural organic matter such as guar and humus are recalcitrant to conventional pretreatment technologies and can potentially foul processes such as membranes during water treatment. An innovative method of using synthetic layered double hydroxides (LDH) was investigated for removing common natural organic matter in the form of guar gum (GG) and humic acid (HA) from water. Adsorption isotherms were evaluated with Langmuir and Freundlich models. Results show the affinity of GG and HA to LDH to be 11.31 and 9.33 mg g(-1) LDH, respectively. Kinetic isotherms indicate that the sorbing rates of LDH to GG and HA increase with initial GG and HA concentrations, fitting a pseudo-second order model. This study demonstrate that LDH may be an effective material in removing GG and HA from waters and offer an alternative to conventional pretreatment technologies for the mitigation fouling of membrane and other systems in water treatment.

  6. Synthesis of Novel Nanocomposites of Silica and Guar Gum:Efficient Zinc Ion Binder

    Institute of Scientific and Technical Information of China (English)

    Vandana; Singh; Sadanand; Pandey; Somit; kumar; Singh; Rashmi; Sanghi

    2007-01-01

    1 Results Adsorption using commercial activated carbon (CAC)[1] can remove heavy metals from wastewater[2-4].However,CAC remains an expensive material for heavy metal removal.Ion exchange techniques are also used but it generates volumetric sludge and increases the cost[5].Using naturally occurring seed polysaccharides can solve these problems but their solubility in water limits its application as an adsorbent.Guar gum is a commercially available,industrially important[6-7] polysaccharide material havi...

  7. Synthesis, Optimization, Property, Characterization, and Application of Dialdehyde Cross-Linking Guar Gum

    Directory of Open Access Journals (Sweden)

    Tang Hongbo

    2016-01-01

    Full Text Available Dialdehyde cross-linking guar gum (DCLGG, as a novel material, was synthesized using phosphorus oxychloride as a cross-linking reagent, sodium periodate as an oxidant, and ethanol as a solvent through keeping the original particle form of guar gum. The process parameters such as the reaction temperature, reaction time, pH, amount of sodium periodate, and amount of ethanol were optimized by the response surface methodology in order to obtain the regression model of the oxidization. The covalent binding of L-asparagine onto the surfaces of DCLGG was further investigated. The results showed that the best technological conditions for preparing DCLGG were as follows: reaction temperature = 40°C, reaction time = 3.0 h, pH = 4.0, and amount of ethanol = 74.5%. The swelling power of DCLGG was intermediate between cross-linking guar gum and dialdehyde guar gum. The cross-linking and dialdehyde oxidization reduced the viscosity of GG. The cross-liking reduced the melting enthalpy of GG. However, the oxidization increased melting enthalpy of ACLGG. The thermal stability of GG was increased by cross-linking or oxidization. The variation of the onset decomposition temperature and end decomposition temperature of GG was not consistent with thermal stability of GG. L-asparagine could be chemically bound well by DCLGG through forming Schiff base under the weak acidity. The maximum adsorption capacity of L-asparagine on DCLGG with aldehyde content of 56.2% reached 21.9 mg/g.

  8. Carboxymethyl guar gum nanoparticles for drug delivery applications: Preparation and preliminary in-vitro investigations

    Energy Technology Data Exchange (ETDEWEB)

    Dodi, G., E-mail: gianina.dodi@yahoo.co.uk [“Gheorghe Asachi” Technical University of Iasi (Romania); SCIENT — Research Centre for Instrumental Analysis, Bucharest (Romania); Pala, A. [University of Sassari, Sassari (Italy); Barbu, E. [University of Portsmouth, Portsmouth (United Kingdom); Peptanariu, D. [“Petru Poni” Institute of Macromolecular Chemistry, Iasi (Romania); Hritcu, D.; Popa, M.I. [“Gheorghe Asachi” Technical University of Iasi (Romania); Tamba, B.I. [“Gr. T. Popa” University of Medicine and Pharmacy, Iasi (Romania)

    2016-06-01

    Carboxymethyl guar gum (CMGG) synthesized from commercially available polysaccharide was formulated into nanoparticles via ionic gelation using trisodium trimetaphosphate (STMP) as cross-linking agent. Characterisation using a range of analytical techniques (FTIR, NMR, GPC, TGA and DLS) confirmed the CMGG structure and revealed the effect of the CMGG and STMP concentration on the main characteristics of the obtained nanoformulations. The average nanoparticle diameter was found to be around 208 nm, as determined by dynamic light scattering (DLS) and confirmed by scanning electron microscopy (SEM) and nanoparticle tracking analysis (NTA). Experiments using simulated gastric and intestinal fluids evidenced significant pH-dependent drug release behaviour of the nanoformulations loaded with Rhodamine B (RhB) as a model drug (loading capacity in excess of 83%), as monitored by UV–Vis. While dose-dependent cytotoxicity was observed, the nanoformulations appeared completely non-toxic at concentrations below 0.3 mg/mL. Results obtained so far suggest that carboxymethylated guar gum nanoparticles formulated with STMP warrant further investigations as polysaccharide based biocompatible drug nanocarriers. - Highlights: • Carboxymethyl guar gum nanoparticles preparation by ionic gelation • The optimum synthesis system designed particles around 200 nm • The nanoformulations appeared completely non-toxic at specific concentrations • The loaded formulations evidenced significant pH-dependent drug release behaviour • The results encourage further investigations as polysaccharidic drug nanocarriers.

  9. Guar gum as a promising starting material for diverse applications: A review.

    Science.gov (United States)

    Thombare, Nandkishore; Jha, Usha; Mishra, Sumit; Siddiqui, M Z

    2016-07-01

    Guar gum is the powdered endosperm of the seeds of the Cyamopsis tetragonolobus which is a leguminous crop. The endosperm contains a complex polysaccharide called galactomannan, which is a polymer of d-galactose and d-mannose. This hydroxyl group rich polymer when added to water forms hydrogen bonding imparting significant viscosity and thickening to the solution. Due to its thickening, emulsifying, binding and gelling properties, quick solubility in cold water, wide pH stability, film forming ability and biodegradability, it finds applications in large number of industries. In last few decades a lot of research has been done on guar gum to fit it into particular application, as such or by its structural modifications. This review gives an overview of the nature, chemistry and properties of guar gum and discusses recent developments in its modifications and applications in major industries like hydraulic fracturing, explosives, food, agriculture, textile, paper, cosmetics, bioremediation, drug delivery, medical and pharmaceuticals. This article would help researchers engaged in biopolymer area and other end-users who want to begin research in natural polysaccharides.

  10. Potential use of curcumin loaded carboxymethylated guar gum grafted gelatin film for biomedical applications.

    Science.gov (United States)

    Manna, Piyali Jana; Mitra, Tapas; Pramanik, Nilkamal; Kavitha, V; Gnanamani, A; Kundu, P P

    2015-04-01

    Present study describes the synthesis of carboxylmethyl guar gum (CMGG) from the native guar gum (GG). Further, the prepared CMGG is grafted with gelatin to form CMGG-g-gelatin and then mixed with curcumin to prepare a biomaterial. The resultant biomaterial is subjected to the analysis of (1)H NMR, ATR-FTIR, TGA, SEM and XRD ensure the carboxymethylation and grafting. The results reveal that 45% of the amine groups of gelatin have been reacted with the--COOH group of CMGG and 90-95% of curcumin is released from CMGG-g-gelatin after 96h of incubation in the phosphate buffer at physiological pH. In vitro cell line studies reveal the biocompatibility of the biomaterial and the antimicrobial studies display the growth inhibition against gram +ve and gram -ve organisms at a considerable level. Overall, the study indicates that the incorporation of curcumin into CMGG-g-gelatin can improve the functional property of guar gum as well as gelatin.

  11. Application of guar-xanthan gum mixture as a partial fat replacer in meat emulsions.

    Science.gov (United States)

    Rather, Sajad A; Masoodi, F A; Akhter, Rehana; Rather, Jahangir A; Gani, Adil; Wani, S M; Malik, A H

    2016-06-01

    The physicochemical, oxidative, texture and microstructure properties were evaluated for low fat meat emulsions containing varying levels of guar/xanthan gum mixture (1:1 ratio) as a fat substitute. Partial replacement of fat with guar/xanthan gum resulted in higher emulsion stability and cooking yield but lower penetration force. Proximate composition revealed that high fat control had significantly higher fat and lower moisture content due to the difference in basic formulation. Colour evaluation revealed that low fat formulations containing gum mixture had significantly lower lightness and higher yellowness values than high fat control formulation. However non-significant difference was observed in redness values between low fat formulations and the high fat control. The pH values of the low fat formulations containing gum mixture were lower than the control formulations (T0 and TC). The MetMb% of the high fat emulsion formulation was higher than low fat formulations. The significant increase of TBARS value, protein carbonyl groups and loss of protein sulphydryl groups in high fat formulation reflect the more oxidative degradation of lipids and muscle proteins during the preparation of meat emulsion than low fat formulations. The SEM showed a porous matrix in the treatments containing gum mixture. Thus, the guar/xanthan gum mixture improved the physicochemical and oxidative quality of low fat meat emulsions than the control formulations.

  12. The effect of guar gum on fluid friction in spiral pipe

    Science.gov (United States)

    Yanuar, Gunawan, Baqi, M.

    2012-06-01

    Pipeline is the most effective equipment to transport of fluid. Based on the shape, pipe can classify as circular, square, triangle and spiral. Each shape has different characteristics. On the transport of fluid using pipe, pressure drop is very important aspect because related with energy consumption. Special pipe as spiral pipe is used as a fuel mixing system of fuel. It is intended to prevent precipitation and to reduce the pressure drop. The purpose of this research is to investigate the reduction of pressure drop in a spiral pipe with the addition biopolymer (guar gum). Spiral pipe with the best aspect ratio, P/Di = 7 is used in this study. Working fluid used guar gum solution of 150 ppm and 200 ppm. Circular pipe with same diameter is used for comparison. Analysis of flow characteristics based on the power law model for non-Newtonian fluid. Experimental was conducted from low to high Reynolds number up to 60,000. The results showed that the effect of biopolymer guar gum solution can reduce drag either on a circular pipe and spiral pipe.

  13. Viscoelastic properties of aqueous guar gum derivative solutions under large amplitude oscillatory shear (LAOS).

    Science.gov (United States)

    Szopinski, Daniel; Luinstra, Gerrit A

    2016-11-20

    The industrial relevant nonlinear viscoelastic properties of aqueous carboxymethyl hydroxypropyl guar gum (CMHPG) and non-ionic hydroxypropyl guar gum (HPG) solutions between semi-dilute and concentrated solution state were investigated by large amplitude oscillatory shear flow (LAOS). Aqueous CMHPG and HPG solutions enter the nonlinear flow regime at deformations γ0>100%. The nonlinear stress waveforms were analyzed by FT-rheology and orthogonal stress decomposition along the MITlaos framework. A rheological fingerprint is generated (Pipkin space) showing that the guar gum derivative solutions undergo a shear-thinning at high strains, which is preceded by a thickening above a minimum strain rate at intermediate strains. The influence and breakup of superstructures/aggregates gives a "rheological fingerprint", a function of the applied deformation and time scale (Pipkin space). A characteristic process time was found that scales exponentially with the overlap parameter with an exponent of 4/2, and is proposed to represent the relaxation process of the superstructure in solution.

  14. Highly viscous guar gum shifts dietary amino acids from metabolic use to fermentation substrate in domestic cats.

    Science.gov (United States)

    Rochus, Kristel; Janssens, Geert P J; Van de Velde, Hannelore; Verbrugghe, Adronie; Wuyts, Birgitte; Vanhaecke, Lynn; Hesta, Myriam

    2013-03-28

    The present study evaluated the potential of affecting amino acid metabolism through intestinal fermentation in domestic cats, using dietary guar gum as a model. Apparent protein digestibility, plasma fermentation metabolites, faecal fermentation end products and fermentation kinetics (exhaled breath hydrogen concentrations) were evaluated. Ten cats were randomly assigned to either guar gum- or cellulose-supplemented diets, that were fed in two periods of 5 weeks in a crossover design. No treatment effect was seen on fermentation kinetics. The apparent protein digestibility (P= 0.07) tended to be lower in guar gum-supplemented cats. As a consequence of impaired small-intestinal protein digestion and amino acid absorption, fermentation of these molecules in the large intestine was stimulated. Amino acid fermentation has been shown to produce high concentrations of acetic and butyric acids. Therefore, no treatment effect on faecal propionic acid or plasma propionylcarnitine was observed in the present study. The ratio of faecal butyric acid:total SCFA tended to be higher in guar gum-supplemented cats (P= 0.05). The majority of large-intestinal butyric acid is absorbed by colonocytes and metabolised to 3-hydroxy-butyrylcoenzyme A, which is then absorbed into the bloodstream. This metabolite was analysed in plasma as 3-hydroxy-butyrylcarnitine, which was higher (P= 0.02) in guar gum-supplemented cats. In all probability, the high viscosity of the guar gum supplement was responsible for the impaired protein digestion and amino acid absorption. Further research is warranted to investigate whether partially hydrolysed guar gum is useful to potentiate the desirable in vivo effects of this fibre supplement.

  15. Effects of guar gum and cellulose on glucose absorption, hormonal release and hepatic metabolism in the pig

    Science.gov (United States)

    Nunes, C. S.; Malmlof, K.

    1992-01-01

    Six Large White pigs (mean body-weight 59 (SE 1.7) kg) were surgically fitted with permanent catheters in the portal vein, the brachiocephalic artery and the right hepatic vein, as well as with electromagnetic flow probes around the portal vein and the hepatic artery, and allowed to recover. The non-anaesthetized animals were given a basal non-fibre diet (diet A) alone or together with 60 g guar gum/kg (diet B) or 150 g purified cellulose/kg (diet C) by substitution for mica. The diets were given for weekly periods and according to a replicated 3 x 3 Latin square design. On the last day of each such adaptation period, test meals of 800 g were given before blood sampling. Sampling was continued for 8 h. Guar gum strongly reduced glucose apparent absorption without changing the absorption and the hepatic uptake profiles. Production rates of insulin, gastric inhibitory polypeptide and insulin-like growth factor-1 (IGF-1) were lowest after guar gum ingestion. However, the reductions in peripheral blood insulin levels caused by guar gum were not associated with a change in hepatic insulin extraction. IGF-1 appeared to be strongly secreted by the gut, whereas the liver had a net uptake of the peptide. Ingestion of guar gum increased the hepatic extraction coefficient of gut-produced IGF-1. Guar gum ingestion appeared also to decrease glucagon secretion. Cellulose at the level consumed had very few effects on the variables considered. It is suggested that the modulation of intestinal mechanisms by guar gum was sufficient to mediate the metabolic effects described.

  16. Beneficial properties of selenium incorporated guar gum nanoparticles against ischemia/reperfusion in cardiomyoblasts (H9c2).

    Science.gov (United States)

    Soumya, R S; Vineetha, V P; Salin Raj, P; Raghu, K G

    2014-11-01

    Nanotechnology for the treatment and diagnosis has been emerging recently as a potential area of research and development. In the present study, selenium incorporated guar gum nanoparticles have been prepared by nanoprecipitation and characterized by transmission electron microscopy and particle size analysis. The nanoparticles were screened for antioxidant potential (metal chelation, total reducing power and hydroxyl radical scavenging activity) and were evaluated against the cell line based cardiac ischemia/reperfusion model with special emphasis on oxidative stress and mitochondrial parameters. The cell based cardiac ischemia model was employed using H9c2 cell lines. Investigations revealed that there was a significant alteration (P ≤ 0.05) in the innate antioxidant status (glutathione↓, glutathione peroxidase↓, thioredoxin reductase↓, superoxide dismutase↓, catalase↓, lipid peroxidation↑, protein carbonyl↑, xanthine oxidase↑ and caspase 3 activity↑), mitochondrial functions (reactive oxygen species generation, membrane potential, and pore opening) and calcium homeostasis (calcium ATPase and intracellular calcium overload) during both ischemia and reperfusion. For comparative evaluation, selenium, guar gum and selenium incorporated guar gum nanoparticles were evaluated for their protective properties against ischemia/reperfusion. The study reveals that selenium incorporated guar gum nanoparticles were better at protecting the cells from ischemia/reperfusion compared to selenium and guar gum nanoparticles. The potent antioxidant capability shown by the sample in in vitro assays may be the biochemical basis of its better biological activity. Further, the nanodimensions of the particle may be the additional factor responsible for its better effect.

  17. AN IN-VITRO STUDY FOR MUCOADHESION AND CONTROL RELEASE PROPERTIES OF GUAR GUM AND CHITOSAN IN ITRACONAZOLE MUCOADHESIVE TABLETS

    Directory of Open Access Journals (Sweden)

    A. A. Shaikh*, Y. D. Pawar and S. T. Kumbhar

    2012-05-01

    Full Text Available This study describes the effect of Guar gum and chitosan on formulation of mucoadhesive drug delivery system of itraconazole. Mucoadhesive strength, Drug content, Hardness, Friability, Weight variation, Moisture content and accelerated stability studies were performed to study the effect of polymers on prepared mucoadhesive tablets. Results of the present study clarified the potential of guar gum and chitosan in mucoadhesion and control release of itraconazole tablets. Both polymers i.e. Chitosan and guar gum were helpful for controlling the drug release in better way when used in proper combinations. When result of mucoadhesion was checked guar gum gives more mucoadhesive strength to the prepared tablets as compared to chitosan. Accelerated stability studies were performed on prepared formulations, results indicates that the formulations were stable that mince excipients used in the formulations were stable and are not causing major changes in drug release pattern after a period of 6 months. From above mentioned work it can be concluded that combination of Chitosan and guar gum is better and effective approach to have controlled mucoadhesive drug delivery system of Itraconazole.

  18. Effect of incorporation of pumpkin (Cucurbita moshchata) powder and guar gum on the rheological properties of wheat flour.

    Science.gov (United States)

    Kundu, Himani; Grewal, Raj Bala; Goyal, Ankit; Upadhyay, Neelam; Prakash, Saurabh

    2014-10-01

    The present study was carried out to study the effect of incorporation of fibre rich pumpkin powder and guar gum on the farinographic characteristics of wheat flour. The flour and pumpkin powder were assessed for proximate composition, total dietary fibre, minerals and β-carotene. Pumpkin powder contained appreciable amount of fibre, minerals and β-carotene. The effects of incorporation of different levels of pumpkin powder and guar gum along with pumpkin powder on farinographic characteristics were studied. Dough development time, dough stability, time to break down and farinograph quality number increased whereas mixing tolerance index decreased with incorporation of pumpkin powder (> 5 %) and guar gum (1.0 and 1.5 %) along with pumpkin powder in the flour. Resistance to extension as well as extensibility of dough prepared increased significantly by adding pumpkin powder (5-15 %) whereas increase in resistance to extension only was noticed with inclusion of guar gum (0.5-1.5 %) to flour containing 5 % pumpkin powder. Results indicated that pumpkin can be processed to powder that can be utilized with guar gum for value addition.

  19. Economic and environmental sustainability analysis of guar (Cyamopsis tetragonoloba L. farming process in a Mediterranean area: two case studies

    Directory of Open Access Journals (Sweden)

    Fabio Gresta

    2014-02-01

    Full Text Available Guar (Cyamopsis tetragonoloba L. is a spring-summer legume with a high drought tolerance, grown mainly in India, Pakistan, United States and South Africa, whose seeds contain galactomannans. These can be used as an emollient, softening or thickening agent, a flocculant, as well as in hydraulic fracturing, and as a stabiliser in a wide range of other industrial activities: the production of cosmetics, paper, textiles, paints and varnishes, detergents, in construction, and in food products (jams, jellies, yogurt, mayonnaise, ketchup, diet foods, foods for coeliacs, etc.. In the light of a growing industrial demand for guar flour, in May 2012 a trial was carried out in southern Italy. Seeds from South Africa were sown in large plots on two farms with different soil characteristics. The crop showed yields varying between 1.8 and 2.2 t ha–1. Agronomic results were then used to conduct an integrated sustainability analysis using the production cost analysis and the life cycle assessment, in order to assess, respectively, the cost-effectiveness and the environmental impact of the production process of guar in a Mediterranean environment. Compared to other competitive crops, guar, with less than 3000 kg of CO2 eq. emissions, can be considered as a low-emission crop. Given the above-mentioned yield, guar growing is economically sustainable when the purchase price of seeds is not less than 0.96 € kg–1.

  20. Sonication-Based Improvement of the Physicochemical Properties of Guar Gum as a Potential Substrate for Modified Drug Delivery Systems

    Directory of Open Access Journals (Sweden)

    Siddique Akber Ansari

    2013-01-01

    Full Text Available Guar Gum is a natural polysaccharide that, due to its physicochemical properties, is extensively investigated for biomedical applications as a matrix for modified drug delivery, but it is also used in the food industry as well as in cosmetics. A commercial sample of Guar Gum was sonicated for different periods of time, and the reduction in the average molecular weight was monitored by means of viscometric measurements. At the same time, the rheological behaviour was also followed, in terms of viscoelasticity range, flow curves, and mechanical spectra. Sonicated samples were used for the preparation of gels in the presence of borate ions. The effect of borax on the new samples was investigated by recording mechanical spectra, flow curves, and visible absorption spectra of complexes with Congo Red. The anisotropic elongation, observed in previous studies with tablets of Guar Gum and borax, was remarkably reduced when the sonicated samples were used for the preparation of the gels.

  1. Microwave assisted synthesis of guar gum grafted sodium acrylate/cloisite superabsorbent nanocomposites: reaction parameters and swelling characteristics.

    Science.gov (United States)

    Likhitha, M; Sailaja, R R N; Priyambika, V S; Ravibabu, M V

    2014-04-01

    In this study, superabsorbent nanocomposites of guar gum grafted sodium acrylate have been synthesized via both microwave and conventional techniques. The reaction parameters of both techniques were optimized and the microwave assisted method was proved to have higher grafting yield with lesser time of reaction as compared to the conventional method. X-ray diffraction and scanning electron microscopy analyses revealed that cloisite was exfoliated and uniformly dispersed in guar gum grafted sodium acrylate matrix. The results show that introducing cloisite into the guar gum grafted sodium acrylate network improved the swelling capability and the swelling rate of the superabsorbent nanocomposite was found to be enhanced at an optimal loading of 10% cloisite. The nanocomposites showed high water absorbency within a wide pH range. Preliminary studies on crystal violet dye removal showed promising results.

  2. Sonication-based improvement of the physicochemical properties of Guar Gum as a potential substrate for modified drug delivery systems.

    Science.gov (United States)

    Ansari, Siddique Akber; Matricardi, Pietro; Cencetti, Claudia; Di Meo, Chiara; Carafa, Maria; Mazzuca, Claudia; Palleschi, Antonio; Capitani, Donatella; Alhaique, Franco; Coviello, Tommasina

    2013-01-01

    Guar Gum is a natural polysaccharide that, due to its physicochemical properties, is extensively investigated for biomedical applications as a matrix for modified drug delivery, but it is also used in the food industry as well as in cosmetics. A commercial sample of Guar Gum was sonicated for different periods of time, and the reduction in the average molecular weight was monitored by means of viscometric measurements. At the same time, the rheological behaviour was also followed, in terms of viscoelasticity range, flow curves, and mechanical spectra. Sonicated samples were used for the preparation of gels in the presence of borate ions. The effect of borax on the new samples was investigated by recording mechanical spectra, flow curves, and visible absorption spectra of complexes with Congo Red. The anisotropic elongation, observed in previous studies with tablets of Guar Gum and borax, was remarkably reduced when the sonicated samples were used for the preparation of the gels.

  3. Insetos visitantes de gomas exsudadas por Terminalia argentea Mart & Zucc (Combretaceae Visiting insects of exudated gums by Terminalia argentea Mart. & Zucc (Combretaceae

    Directory of Open Access Journals (Sweden)

    Samuel Boff

    2008-09-01

    Full Text Available Uma das fontes efêmeras de alimento que os insetos podem utilizar são as gomas exsudadas por plantas. No mês de maio de 2005, em uma área de cerrado no município de Campo Grande, Mato Grosso do Sul, foram observados insetos visitando as estruturas de exsudação em um indivíduo de Terminalia agentea Mart & Zucc (Combretaceae. Foram registradas 19 espécies, principalmente Trigona branneri (Cockerell e Mesembrinella bicolor (Fabricius. Todos os visitantes foram observados coletando ou ingerindo a goma exsudada. Observações sobre o horário de visitação e comportamento das espécies mais abundantes são relatadas. As amostras de exsudatos apresentaram baixa concentração de proteínas e açucares redutores e alta concentração de carboidratos complexos, permitindo inferir que os visitantes de T. argentea buscam na goma um recurso alimentar de alta massa molecular que contribui para o armazenamento de reservas energéticas.One of the ephemeral food sources that insects may use is the exudated gums from plants. In May 2005, in an area of Cerrado from Campo Grande, Mato Grosso do Sul, Brazil, insects visiting an exudation structure of an individual of Terminalia argentea Mart & Zucc (Combretaceae were observed. Nineteen species were identified, mainly Trigona branneri (Cockerel and Mesembrinella bicolor (Fabricius. All visitors had been observed collecting or ingesting the gum. Visitation time and behavior of the most abundant species were reported. Samples of exudates showed a low concentration of proteins and reducing sugars and high concentration of complex carbohydrate, allowing infer that visitors of T. argentea seek the gum a food resource of high molecular weight that contributes to the storage of energy reserves.

  4. Quality assurance of malaria case management in an urban and in sub-rural health centres in Goma, Congo

    Directory of Open Access Journals (Sweden)

    Prosper M. Lutala

    2011-02-01

    Full Text Available Background: Every year, up to three million deaths throughout the world occur as a result of malaria, 90% of which occur in Africa. Despite training providers in malaria case management and the availability of appropriate medical suppliers, there are still weaknesses in the management chain of malaria.Objectives: Our aim was to assess the quality of malaria case management in two primary health care centres in the Goma health district. Specific objectives were the assessment of quality accuracy in the dosage, the duration of treatment, the intervals between administrations, and the routes of administration of anti-malarial medication in two health centres, as well as the subsequent comparison of those two sites. Method: A descriptive retrospective study was conducted using the malaria register’s review to assess two health centres in the Goma health district. Socio-demographical and clinical data were recorded and the quality was assessed against the national guidelines. Descriptive statistics with percentages and Chi-square values were computed. Results: Under-dosage was more common in CCLK (Centre Chrétien du Lac Kivu [Lake Kivu Christian Centre] with 55 patients (62.5%; 95% CI, 52% – 71.8% patients, whilst the over-dosage was present in 64 patients (80%; 95% CI, 69.9% – 87.2% in CASOP (Caisse de Solidarité Ouvrière et Paysanne [Fund of Solidarity Workers and Peasants]. The duration of treatment was shorter in CCLK in 15 patients (93.7%; 95% CI, 71.6% – 98.8%; CASOP had a high rate of inappropriate intervals between the administration of drugs in 14 patients (82.3%; 95% CI, 58.9% – 93.8%. Intravenous administration rates were high in both sites with respectively 102 patients in CASOP (62.5%; 95% CI, 54.9% – 69.6% and 61 patients in CCLK (37.4%; 95% CI, 30.3% – 45.0%. Significant differences were found between the two sites with regard to intervals of administration (χ2 = 7.11, p = 0.007, duration of treatment (χ2 = 8.51, p

  5. Health care seeking and financial behaviours of the elderly during wartime in Goma, Democratic Republic of Congo

    Directory of Open Access Journals (Sweden)

    M. Prosper Lutala

    2010-03-01

    Full Text Available Background: Health and social services utilisation is seen to be more closely related to age than to other socio-demographic characteristics. Many health problems are known to increase with age and this demographic trend may lead to an increase in the absolute number of health conditions in this population. However, questions are still emerging as to how the elderly seek care in response to their needs in the context of a war-torn region. Objectives: The aim of this study was to determine the behaviour of the elderly in seeking care during a time of conflict.Method: A descriptive cross-sectional study was carried out in the health district Goma, in the Democratic Republic of the Congo (DRC, using a multistage sampling of 500 senior citizens. Eight trained field-workers were deployed in the field where they administered a structured questionnaire.Results: The public health sector was well known and preferred by 186 participants (37.2%, but only used by 16 (3.2% participants. Financial support received by the elderly came from their own relatives and fellow believers in 33.5% and 20.2% of cases, respectively. Almost 71% of monetary support is the result of begging and unknown sources – there is no government involvement whatsoever. Much of the external support that the elderly receive involves support in the form of food. Disease expenses remain a main concern of the elderly themselves.Conclusion: Government support for the elderly in the DRC is non-existent. There is an overuse of private sector and traditional medicine, despite the preference indicated for the public health sector. As a recommendation, a general increase in income-related activities could contribute to alleviating the health state of the elderly in a war situation. Further studies might explore in future the contribution of those results on the health of elders.

  6. Health care seeking and financial behaviours of the elderly during wartime in Goma, Democratic Republic of Congo

    Directory of Open Access Journals (Sweden)

    M. Prosper Lutala

    2010-03-01

    Full Text Available Background: Health and social services utilisation is seen to be more closely related to age than to other socio-demographic characteristics. Many health problems are known to increase with age and this demographic trend may lead to an increase in the absolute number of health conditions in this population. However, questions are still emerging as to how the elderly seek care in response to their needs in the context of a war-torn region. Objectives: The aim of this study was to determine the behaviour of the elderly in seeking care during a time of conflict.Method: A descriptive cross-sectional study was carried out in the health district Goma, in the Democratic Republic of the Congo (DRC, using a multistage sampling of 500 senior citizens. Eight trained field-workers were deployed in the field where they administered a structured questionnaire.Results: The public health sector was well known and preferred by 186 participants (37.2%, but only used by 16 (3.2% participants. Financial support received by the elderly came from their own relatives and fellow believers in 33.5% and 20.2% of cases, respectively. Almost 71% of monetary support is the result of begging and unknown sources – there is no government involvement whatsoever. Much of the external support that the elderly receive involves support in the form of food. Disease expenses remain a main concern of the elderly themselves.Conclusion: Government support for the elderly in the DRC is non-existent. There is an overuse of private sector and traditional medicine, despite the preference indicated for the public health sector. As a recommendation, a general increase in income-related activities could contribute to alleviating the health state of the elderly in a war situation. Further studies might explore in future the contribution of those results on the health of elders.

  7. A three-layer guar gum matrix tablet for oral controlled delivery of highly soluble metoprolol tartrate.

    Science.gov (United States)

    Krishnaiah, Y S R; Karthikeyan, R S; Satyanarayana, V

    2002-07-25

    The objective of the study is to design oral controlled drug delivery systems for highly water-soluble drugs using guar gum as a carrier in the form of a three-layer matrix tablet. Metoprolol tartrate was chosen as a model drug because of its high water solubility. Matrix tablets containing either 30 (M1), 40 (M2) or 50% (M3) of guar gum were prepared by wet granulation technique using starch paste as a binder. Three-layer matrix tablets of metoprolol tartrate were prepared by compressing on both sides of guar gum matrix tablet granules of metoprolol tartrate M1, M2 or M3 with either 50 (TL1M1, TL1M2 or TL1M3) or 75 mg (TL2M1, TL2M2 or TL2M3) of guar gum granules as release retardant layers. Both the matrix and three-layer matrix tablets were evaluated for hardness, thickness, drug content uniformity, and subjected to in vitro drug release studies. The amount of metoprolol tartrate released from the matrix and three-layer matrix tablets at different time intervals was estimated by using a HPLC method. Matrix tablets of metoprolol tartrate were unable to provide the required drug release rate. However, the three-layer guar gum matrix tablets (TL2M3) provided the required release rate on par with the theoretical release rate for metoprolol tartrate formulations meant for twice daily administration. The three-layer guar gum matrix tablet (TL2M3) showed no change either in physical appearance, drug content or in dissolution pattern after storage at 40 degrees C/75% RH for 6 months. The FT-IR study did not show any possibility of metoprolol tartrate/guar gum interaction with the formulation excipients used in the study. The results indicated that guar gum, in the form of three-layer matrix tablets, is a potential carrier in the design of oral controlled drug delivery systems for highly water-soluble drugs such as metoprolol tartrate.

  8. [done no pages] An overview on applications of guar gum in food systems to modify structural properties

    Directory of Open Access Journals (Sweden)

    Biljana B. Popova

    2017-01-01

    Full Text Available Polysaccharides define as complex polymers composed of units interlinked with glycosidic bonds originated naturally. Polysaccharides are categorizing in several groups and among them, Gums are those with critical roles in food systems. Guar Gum is imparting softness, emulsification, stabilizing via its addition to formulas. This Gum is a fast soluble in cold water and can be active in a wide range of pH. The aim of this overview is giving an initial concept about guar gum and then convey to an introduction of its applications in food industries.

  9. Fracturing Fluid (Guar Polymer Gel Degradation Study by using Oxidative and Enzyme Breaker

    Directory of Open Access Journals (Sweden)

    Aung Kyaw

    2012-06-01

    Full Text Available Oxidative and enzyme breakers are used in this research project with the main objective to study on the degradation pattern of fracturing fluid (i.e., guar polymer gel as a function of time, temperature and breaker concentration itself. The fracturing fluid used in hydraulic fracturing or frac pack contain a chemical breakers to reduce the viscosity of the fluid intermingled with the proppant. Chemical breakers reduce viscosity of the guar polymer by cleaving the polymer into small-molecular-weight fragments. The reduction of viscosity will facilitate the flow-back of residual polymer providing rapid recovery of polymer from proppant pack. Ineffective breakers or misapplication of breakers can result in screen-outs or flow-back of viscous fluids both of which can significantly decrease the well productivity. Breaker activity of low to medium temperature range oxidative and enzyme breaker systems was evaluated. ViCon NF an oxidative breaker (Halliburton product and GBW 12- CD an enzyme breaker (BJ Services product were used in this research project with the main objective to study on the degradation pattern of fracturing fluid (guar polymer gel as a function of (time, temperature and breaker concentration itself. This study provides focuses on the way to mix the fracturing fluid, compositions of the fracturing fluid and how to conduct the crosslink and break test. Crosslink test indicate the optimum cross-linker concentration to produce good crosslink gel and the break test gave the characteristic of the gel during degradation process and also the break time. Besides relying on the laboratory experiment, information obtained from research on SPE and US Pattern papers were used to make a comparison study on oxidative and enzyme breakers properties. Degradation pattern observed from the break test showed that reduction in gel viscosity depends on time, temperature and breaker concentration. Observations from experiment also revealed that small

  10. Guar Gum Stimulates Biogenic Sulfide Production at Elevated Pressures: Implications for Shale Gas Extraction.

    Science.gov (United States)

    Nixon, Sophie L; Walker, Leanne; Streets, Matthew D T; Eden, Bob; Boothman, Christopher; Taylor, Kevin G; Lloyd, Jonathan R

    2017-01-01

    Biogenic sulfide production is a common problem in the oil industry, and can lead to costly hydrocarbon processing and corrosion of extraction infrastructure. The same phenomenon has recently been identified in shale gas extraction by hydraulic fracturing, and organic additives in fracturing fluid have been hypothesized to stimulate this process. Constraining the relative effects of the numerous organic additives on microbial metabolism in situ is, however, extremely challenging. Using a bespoke bioreactor system we sought to assess the potential for guar gum, the most commonly used gelling agent in fracturing fluids, to stimulate biogenic sulfide production by sulfate-reducing microorganisms at elevated pressure. Two pressurized bioreactors were fed with either sulfate-amended freshwater medium, or low-sulfate natural surface water, in addition to guar gum (0.05 w/v%) and an inoculum of sulfate-reducing bacteria for a period of 77 days. Sulfide production was observed in both bioreactors, even when the sulfate concentration was low. Analysis of 16S rRNA gene sequences indicate that heterotrophic bacteria closely associated with the genera Brevundimonas and Acinetobacter became enriched early in the bioreactor experiments, followed by an increase in relative abundance of 16S rRNA genes associated with sulfate-reducing bacteria (Desulfosporosinus and Desulfobacteraceae) at later time points. Results demonstrate that guar gum can stimulate acid- and sulfide-producing microorganisms at elevated pressure, and may have implications for the potential role in microbially induced corrosion during hydraulic fracturing operations. Key differences between experimental and in situ conditions are discussed, as well as additional sources of carbon and energy for biogenic sulfide production during shale gas extraction. Our laboratory approach can be tailored to better simulate deep subsurface conditions in order to probe the role of other fracturing fluid additives and downhole

  11. Design and evaluation of guar gum-based ofloxacin sustained release ocular insert

    Directory of Open Access Journals (Sweden)

    Sunil Kumar

    2012-01-01

    Full Text Available To prepare ocular inserts of ofloxacin using guar gum as a polymer for sustained delivery over a period of 24 h. Ofloxacin ocular inserts were prepared by the solvent casting method using guar gum in different proportions (0.5% w/v, 0.75% w/v and 1.0% w/v. The prepared formulations were evaluated for thickness, weight variation, percentage drug content, surface pH, folding endurance, percentage moisture absorption and loss, percentage swelling, mechanical strength and in vitro transcorneal permeation. In vitro transcorneal permeation study was performed on goat cornea using a modified Franz diffusion cell. The inserts were found to be of uniform thickness (ranging from 51.230 ± 0.385 μm to 109.275 ± 0.522 μm and weight (1.720 ± 0.079 mg to 3.402 ± 0.105 mg. The % drug content in the inserts was found to vary between 95.450 ± 0.427% and 98.471 ± 0.225. The cumulative % drug releases from the formulation ranged from 38.19 to 75.21 over a period of 24 h. All the formulations followed a zero order release pattern. The in vitro transcorneal study revealed that an increase in concentration of the polymer slowed down the release of ofloxacin from the formulation. Ocular inserts using guar gum as a polymer were successfully prepared and can be effectively used for sustained ocular delivery over a period of 24 h.

  12. 5-Fluorouracil loaded guar gum microspheres for colon delivery:preparation, characterization and in vitro release

    Institute of Scientific and Technical Information of China (English)

    KAUSHIK Dinesh; SARDANA Satish; MISHRA DN

    2009-01-01

    The present investigation is aimed to develop a new formulation containing chemically cross-linked guar gum microspheres loaded with 5-fluorouracil for targeting colorectal cancer. The emulsification polymerization method involving the dispersion of aqueous phase of guar gum in castor oil was used to prepare spherical microspheres. Various processing parameters were studied in order to optimize the formulation. Particle size and surface morphology of the microspheres were determined using optical microscopy and scanning electron microscopy. The in vitro drug release studies performed in simulated gastric fluid (SGF) for 2 h followed by intestinal fluid for 3 h, revealed the retention of the drug inside the microspheres from which only (15.27±0.56)% of the drug was released in 5 h. In vitro release rate studies were also carried out in simulated colonic fluid (SCF) in the presence of rat caecal contents, which showed improved drug release. The drug release from the formulation was found to be (41.6±3.5) % with 2% (w/v) caecal matter in 24 h as compared to control study where (25.2±3.5) % of drug was released. The drug release from the formulation with 2% and 4% rat caecal contents medium after 2 days of enzyme induction was found to be (56.3±4.1) % and (78.9±2.8) % in 24 h respectively. Similarly, (61.3±5.4) % and (90.2±2.9) % drug was released respectively with 2% and 4% rat caecal matter after 4 days of enzyme induction and (72.1±2.9) % and (90.2±3.2) % after 6 days of enzyme induction. In this way, 5-fluorouracil loaded guar gum microspheres have shown promising results in the management of colorectal cancer, warranting thorough in vivo study for scale up technology.

  13. Effective remediation of phenol,2,4-bis(1,1-dimethylethyl) and bis(2-ethylhexyl) phthalate in farm effluent using Guar gum--A plant based biopolymer.

    Science.gov (United States)

    Kee, Yang Ling; Mukherjee, Sumona; Pariatamby, Agamuthu

    2015-10-01

    This study was carried out to evaluate the efficiency of Guar gum in removing Persistent Organic Pollutants (POPs), viz. phenol,2,4-bis(1,1-dimethylethyl) and bis(2-ethylhexyl) phthalate (DEHP), from farm effluent. The removal efficiency was compared with alum. The results indicated that 4.0 mg L(-1) of Guar gum at pH 7 could remove 99.70% and 99.99% of phenol,2,4-bis(1,1-dimethylethyl) and DEHP, respectively. Box Behnken design was used for optimization of the operating parameters for optimal POPs removal. Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR) spectroscopy studies were conducted on the flocs. SEM micrographs showed numerous void spaces in the flocs produced by Guar gum as opposed to those produced by alum. This indicated why Guar gum was more effective in capturing and removal of suspended particles and POPs as compared to alum. FTIR spectra indicated a shift in the bonding of functional groups in the flocs produced by Guar gum as compared to raw Guar gum powder signifying chemical attachment of the organics present in the effluent to the coagulant resulting in their removal. Guar gum is highly recommended as a substitute to chemical coagulant in treating POPs due to its non-toxic and biodegradable characteristics.

  14. Predictors of Persistent Anaemia in the First Year of Antiretroviral Therapy: A Retrospective Cohort Study from Goma, the Democratic Republic of Congo.

    Science.gov (United States)

    Akilimali, Pierre Zalagile; Kashala-Abotnes, Espérance; Musumari, Patou Masika; Kayembe, Patrick Kalambayi; Tylleskar, Thorkild; Mapatano, Mala Ali

    2015-01-01

    Anaemia is associated with adverse outcomes including early death in the first year of antiretroviral therapy (ART). This study reports on the factors associated with persistent anaemia among HIV-infected patients initiating ART in the Democratic Republic of Congo (DR Congo). We conducted a retrospective cohort study and analyzed data from patients receiving HIV care between January 2004 and December 2012 at two major hospitals in Goma, DR Congo. Haemoglobin concentrations of all patients on ART regimen were obtained prior to and within one year of ART initiation. A logistic regression model was used to identify the predictors of persistent anaemia after 12 months of ART. Of 756 patients, 69% of patients were anaemic (IC95%: 65.7-72.3) at baseline. After 12 months of follow up, there was a 1.2 g/dl average increase of haemoglobin concentration (P anaemia at the beginning, 33% (147/445) had the condition resolved. Among patients with anaemia at ART initiation, those who did not receive cotrimoxazole prophylaxis before starting ART(AOR 3.89; 95% CI 2.09-7.25; P anaemia. More than two thirds of patients had anaemia at baseline. The AZT-containing regimen and absence of cotrimoxazole prophylaxis before starting ART were associated with persistent anaemia 12 months, after initiation of treatment. Considering the large proportion of patients with persistence of anaemia at 12 months, we suggest that it is necessary to conduct a large study to assess anaemia among HIV-infected patients in Goma.

  15. Taphonomy and paleoecology inferences of vertebrate ichnofossils from Guará Formation (Upper Jurassic), southern Brazil

    Science.gov (United States)

    Dentzien-Dias, Paula C.; Schultz, Cesar L.; Bertoni-Machado, Cristina

    2008-03-01

    In southern Brazil, the eolian facies of the Guará Formation (Late Jurassic) reveal footprints and trackways of vertebrates (dinosaurs), as well as burrows made by small vertebrates. All the footprints and trackways are preserved in dunes and sand sheets. The footprints made in the sand sheets are not well preserved due to intense trampling and can be distinguished only by the deformation of the sandstone laminations. In some cases it is possible to see this deformation in plan and in section. Tracks of theropods, ornithopods and middle-sized sauropods are present. Two footprints preserved in the foreset of a paleodune permitted recognition of slide structures and identification of the trackmaker, a theropod. Burrows horizontally across the foresets were found at this same paleodune. Ribbons of massive sandstone - interpreted as the partial filling of the base of the burrows - covered by little blocks of stratified sandstone - suggest the collapse of the burrow roof inward. There are no body fossils in the Guará Formation, consequently the preservation of these tracks provides unique evidence of widespread dinosaurs activity in southern Brazil near the end of the Jurassic.

  16. Guar gum succinate as a carrier for colon-specific drug delivery.

    Science.gov (United States)

    Seeli, D Sathya; Prabaharan, M

    2016-03-01

    A novel type of pH-sensitive colon-specific controlled drug delivery carrier based on guar gum succinate (GGS) was prepared by reacting guar gum (GG) with succinic anhydride (SA) in the presence of 4-dimethylaminopyridine (DMAP). The formation of GGS was confirmed by FT-IR and (1)H NMR and characterized using XRD techniques. GGS microparticles with 460-740 μm in size were prepared using sodium trimetaphosphate (STMP) as a cross-linking agent. The size and morphologies of GGS microparticles were assessed by scanning electron microscopy (SEM). The swelling degree of the GGS microparticles was found to be higher in pH 7.4 than in pH 1.2. In addition, GGS microparticles showed a pH dependent drug release profile when compared to the GG microparticles. The MTT assay revealed that there is no apparent cytotoxicity of GGS against a mouse mesenchymal stem cell line at a concentration range of 0-200 μg/ml. These results confirm that GGS could be used as a carrier for colon-specific drug delivery.

  17. Fabrication and fluorescent labeling of guar gum nanoparticles in a surfactant free aqueous environment.

    Science.gov (United States)

    Ghosh, Sumanta Kumar; Abdullah, Farooque; Mukherjee, Arup

    2015-01-01

    Guar gum (GG) is a galactomannan obtained from the seeds of Cyamopsis tetragonoloba. GG polysaccharide is used in a range of technology arenas and its properties in water environment elicited a lot of interest. We report a simple acid hydrolysis technique to derive water dispersible spherical nanoparticles from GG for the first time without any stabilizing surfactant. The particles demonstrated colloidal stability and were observed to carry negative surface charges in aqueous environment. The TEM study of guar gum nanoparticles (GGn) indicated a size range of 30-80 nm with a mean at 48.8 nm. Mineral acid at apposite concentration have apparently solubilized the amorphous regions of the polymer chain leaving the crystalline parts. GGn were further covalently functionalized in aqueous environment with fluorescein isothiocyanate (FITC) using a hydroxy-propyl amine spacer group. Nanoparticle fluorescence intensity can be modulated with pH changes and a significant augmentation in the intensity was noticed at the physiologically relevant range of 6-8. New fluorescently labeled nanoparticles have potential for applications in bioimaging, biomolecular interaction studies and as a pH sensing probe in sub cellular environment.

  18. Interactions between fluorinated cationic guar gum and surfactants in the dilute and semi-dilute solutions.

    Science.gov (United States)

    Wang, Chen; Li, Xiaorui; Li, Peizhi; Niu, Yuhua

    2014-01-01

    The interactions between the fluorinated cationic guar gum (FCGG) and ionic surfactants including cetyl trimethyl ammonium bromide (CTAB) and sodium lauryl sulfate (SDS) were studied by light scattering, fluorescence spectroscopy, UV-spectrophotometer, (19)F NMR and dynamic rheometer, respectively. The FCGG is prepared with cationic guar gum, isophorone diisocyanate and 2,2,3,4,4,4-hexafluoro-1-butanol. The results show that, with the addition of the surfactants, the stretching degree of the FCGG chains is increased in the FCGG/CTAB solutions, while the dramatical shrinking of FCGG chain, the phase separation and the re-stretched macromolecules appear successively because of the electricity neutralization reaction in the FCGG/SDS system. The mixed hydrophobic domains in all solutions will be reinforced and then dismantled. The solution elasticity shows up the maximum value accordingly. The surfactants can be embedded in the micro-domains and then hinder the fluorinated segmental motions. The interactions between FCGG and SDS are much stronger than those between FCGG and CTAB.

  19. Guar gum-g-N,N'-dimethylacrylamide: synthesis, characterization and applications.

    Science.gov (United States)

    Pandey, Vijay Shankar; Verma, Shiv Kumar; Yadav, Mithilesh; Behari, Kunj

    2014-01-01

    The graft copolymerization of N,N'-dimethylacrylamide onto guar gum initiated by potassium peroxymonosulphate/glycolic acid redox pair in an aqueous medium was studied gravimetrically under a nitrogen atmosphere. Grafting ratio, grafting efficiency and add on increase on increasing the concentration of potassium peroxymonosulphate (8.0 × 10(-3) to 24.0 × 10(-3) mol dm(-3)) and glycolic acid concentration (4.4 × 10(-3) to 7.6 × 10(-3) mol dm(-3)). On increasing the hydrogen ion concentration from 4 × 10(-3) to 12.0 × 10(-3) mol dm(-3), grafting ratio, efficiency, add on and conversion were increased. Maximum grafting was obtained when guar gum and N,N'-dimethylacrylamide concentration were 1.0 × 10(-2) g dm(-3) and 14.0 × 10(-2) mol dm(-3), respectively. An increase in temperature from 25 °C to 45 °C, the grafting ratio increases but conversion and homopolymer decrease. The optimum time period for graft copolymerization was 2h. The graft copolymers were characterized by IR spectroscopy and thermogravimetric analysis.

  20. Carboxymethyl guar gum nanoparticles for drug delivery applications: Preparation and preliminary in-vitro investigations.

    Science.gov (United States)

    Dodi, G; Pala, A; Barbu, E; Peptanariu, D; Hritcu, D; Popa, M I; Tamba, B I

    2016-06-01

    Carboxymethyl guar gum (CMGG) synthesized from commercially available polysaccharide was formulated into nanoparticles via ionic gelation using trisodium trimetaphosphate (STMP) as cross-linking agent. Characterisation using a range of analytical techniques (FTIR, NMR, GPC, TGA and DLS) confirmed the CMGG structure and revealed the effect of the CMGG and STMP concentration on the main characteristics of the obtained nanoformulations. The average nanoparticle diameter was found to be around 208 nm, as determined by dynamic light scattering (DLS) and confirmed by scanning electron microscopy (SEM) and nanoparticle tracking analysis (NTA). Experiments using simulated gastric and intestinal fluids evidenced significant pH-dependent drug release behaviour of the nanoformulations loaded with Rhodamine B (RhB) as a model drug (loading capacity in excess of 83%), as monitored by UV-Vis. While dose-dependent cytotoxicity was observed, the nanoformulations appeared completely non-toxic at concentrations below 0.3 mg/mL. Results obtained so far suggest that carboxymethylated guar gum nanoparticles formulated with STMP warrant further investigations as polysaccharide based biocompatible drug nanocarriers.

  1. Thermoresponsive magnetic nanoparticle--aminated guar gum hydrogel system for sustained release of doxorubicin hydrochloride.

    Science.gov (United States)

    Murali, Ragothaman; Vidhya, Ponraj; Thanikaivelan, Palanisamy

    2014-09-22

    Hydrogel based sustained drug delivery system has evolved as an immense treatment method for solid tumors over the past few decades with long term theranostic ability. Here, we synthesized an injectable hydrogel system comprising biocompatible aminated guar gum, Fe3O4-ZnS core-shell nanoparticles and doxorubicin hydrochloride. We show that amination of guar gum resulted in attraction of water molecules thereby forming the hydrogel without using toxic crosslinking agents. Hydrogel formation was observed at 37°C and is stable up to 95°C. The prepared hydrogel is also stable over a wide pH range. The in vitro studies show that the maximum de-gelation and drug release up to 90% can be achieved after 20 days of incubation. Studies reveal that the drug and the core-shell nanoparticles can be released slowly from the hydrogel to provide the healing and diagnosis of the solid tumor thereby avoiding several drug administrations and total excision of organs.

  2. Alginate beads of Captopril using galactomannan containing Senna tora gum, guar gum and locust bean gum.

    Science.gov (United States)

    Pawar, Harshal A; Lalitha, K G; Ruckmani, K

    2015-05-01

    Gastro-retentive Captopril loaded alginate beads were prepared by an ionotropic gelation method using sodium alginate in combination with natural gums containing galactomannans (Senna tora seed gum, guar gum and locust bean gum) in the presence of calcium chloride. The process variables such as concentration of sodium alginate/natural polymer, concentration of calcium chloride, curing time, stirring speed and drying condition were optimized. Prepared beads were evaluated for various parameters such as flow property, drug content and entrapment efficiency, size and shape, and swelling index. Surface morphology of the beads was studied using scanning electron microscopy. In vitro mucoadhesion and in vitro drug release studies were carried out on the prepared beads. From the entrapment efficiency and dissolution study, it was concluded that galactomannans in combination with sodium alginate show sustained release property. The bead formulation F4 prepared using combination of sodium alginate and guar gums in the ratio 2:1 showed satisfactory sustained release for 12h. The release of Captopril from the prepared beads was found to be controlled by the swelling of the polymer followed by drug diffusion through the swelled polymer and slow erosion of the beads.

  3. The use of molecular dynamics for the study of solution properties of guar gum

    Science.gov (United States)

    Laguna, M. Teresa R.; Tarazona, M. Pilar; Saiz, Enrique

    2003-07-01

    Size exclusion chromatography with dual detection, i.e., employing a refractive index, concentration sensitive, detector together with a multiangle light scattering detector which is sensitive to molecular size, has been applied to study the solution properties of guar gum in water with different concentrations of K2SO4 at 25 °C. The analysis of a single highly polydisperse sample is enough for obtaining calibration curves for molecular weight and radius of gyration and the scaling law coefficients. The influence of the ionic strength on the conformational properties of the polymer can also be analyzed. Moreover, unperturbed dimensions can be obtained by extrapolation of the values measured in a good solvent. The value of the characteristic ratio of the unperturbed dimensions thus obtained is Cn=0/nl2≈19±1. A theoretical analysis is also included. Thus, molecular dynamics procedures were employed to analyze the conformational properties of an oligomer of guar gum under different conditions; namely, standing alone in vacuo, in bulk solid state and in water solution, both with and without salt. These conformational properties were then employed to compute molecular dimensions of Monte Carlo generated chains with different lengths according to standard procedures of the matrix multiplication scheme, thus allowing the evaluation of both perturbed and unperturbed dimensions which are in very good agreement with the experimental values. Moreover our result permits the explanation of the discrepancies among experimental and theoretical values reported in the literature.

  4. Study of hydroxy propyl guar derivative for its gelling property and it's use in the formulation of tenoxicam gels.

    Science.gov (United States)

    Swamy, N G N; Dharmarajan, T S; Paranjothi, K L K

    2007-01-01

    Gels of tenoxicam 1% w/w were formulated using 2% w/w hydroxy propyl guar derivative and 3% w/w sodium carboxy methyl cellulose as gelling agents. A detailed rheological investigation was carried out to study the influence of preservative, drug and preservative, solvent system and the preservative, drug, solvent system and the preservative on the pseudoplastic behaviour of polymers. Hydroxy propyl guar derivative in 2% w/w strength resulted in gels with a higher pseudoplastic index value of 3.383 in contrast to an index value of 1.797 for a 3% w/w sodium carboxy methyl cellulose gels of a similar composition. The gels were stored at different temperatures and variations in pH values were recorded. Hydroxy propyl guar derivative based gels revealed variations in pH values over a narrow range in contrast to sodium carboxy methyl cellulose gels. The gels were subjected to short term stability studies by storing gels at refrigerated temperature, lab temperature, at 37 degrees C and at 45 degrees C. Gels based on hydroxy propyl guar derivative revealed better drug keeping qualities in contrast to sodium carboxy methyl cellulose stabilized gels. Release studies of tenoxicam from formulations across hairless albino mice skin revealed a zero order drug release pattern from both the formulations.

  5. Graft [partially carboxymethylated guar gum-g-poly N-(hydroxymethyl) acrylamide] copolymer: from synthesis to applications.

    Science.gov (United States)

    Pandey, Vijay Shankar; Verma, Shiv Kumar; Behari, Kunj

    2014-09-22

    Graft copolymer of N-(hydroxymethyl) acrylamide with carboxymethylated guar gum was synthesized and the reaction conditions were optimized for better yield using potassium peroxymonosulfate and thiourea as a redox initiator. The optimum reaction conditions for grafting have also been determined by studying the effect of N-(hydroxymethyl) acrylamide, hydrogen ion, peroxymonosulphate, thiourea concentration and carboxymethylated guar gum along with time and temperature. Experimental results show that maximum grafting has been obtained at 1.4 g dm(-3) concentration of carboxymethylated guar gum and 16×10(-2) mol dm(-3) concentration of N-(hydroxymethyl) acrylamide. It has been observed that grafting ratio, add on, conversion, efficiency and rate of grafting increase up to 6.0×10(-3) mol dm(-3) of hydrogen ion, 2.4×10(-3) mol dm(-3) of thiourea, 14×10(-3) mol dm(-3) of peroxymonosulphate and 35°C of temperature. Grafted copolymer has been characterized by FTIR spectroscopy and thermogravimetric analysis. Water swelling, flocculating, and metal ion uptake properties of partially carboxymethylated guar gum-g-N-(hydroxymethyl) acrylamide have been determined.

  6. Influence of innovative technologies on rheological and thermophysical properties of whey proteins and guar gum model systems

    Directory of Open Access Journals (Sweden)

    Greta Krešić

    2011-03-01

    Full Text Available The aim of this study was to examine the effect of high-power ultrasound (US and highpressure processing (HP on model systems composed of whey protein concentrate (WPC and whey protein isolate (WPI with or without guar gum addition. This kind of systems can be found in food production industry so the aim was to use novel food processing technologies to be utilized as a method for products development. Aqueous suspensions (10 g kg-1 of powdered whey proteins were treated with either ultrasound or high pressure. The treatment conditions were as follows: US: frequency of 30 kHz, for 5 and 10 min; HP: pressure intensity 300-600 MPa, for 5 and 10 min. Rheological and thermophysical properties were analyzed after guar gum addition (0.5 g kg-1. Ultrasound treatment showed a significant influence on all examined properties through protein denaturation caused by cavitation and microstreaming effects. High pressure caused significant increase in viscosity and consistency coefficients of model systems with and without guar addition. Significant decrease of initial freezing and initial thawing temperature was observed in all samples. With this research the direct influence of ultrasound and high-pressure treatment on the rheological and thermophysical properties of whey protein isolate and concentrate model systems with or without guar gum was demonstrated.

  7. Molecular Properties of Guar Gum and Pectin Modify Cecal Bile Acids, Microbiota, and Plasma Lipopolysaccharide-Binding Protein in Rats.

    Science.gov (United States)

    Ghaffarzadegan, Tannaz; Marungruang, Nittaya; Fåk, Frida; Nyman, Margareta

    2016-01-01

    Bile acids (BAs) act as signaling molecules in various physiological processes, and are related to colonic microbiota composition as well as to different types of dietary fat and fiber. This study investigated whether guar gum and pectin-two fibers with distinct functional characteristics-affect BA profiles, microbiota composition, and gut metabolites in rats. Low- (LM) or high-methoxylated (HM) pectin, and low-, medium-, or high-molecular-weight (MW) guar gum were administered to rats that were fed either low- or high-fat diets. Cecal BAs, short-chain fatty acids (SCFA) and microbiota composition, and plasma lipopolysaccharide-binding protein (LBP) levels were analyzed, by using novel methodologies based on gas chromatography (BAs and SCFAs) and 16S rRNA gene sequencing on the Illumina MiSeq platform. Strong correlations were observed between cecal BA and SCFA levels, microbiota composition, and portal plasma LBP levels in rats on a high-fat diet. Notably, guar gum consumption with medium-MW increased the cecal amounts of cholic-, chenodeoxycholic-, and ursodeoxycholic acids as well as α-, β-, and ω-muricholic acids to a greater extent than other types of guar gum or the fiber-free control diet. In contrast, the amounts of cecal deoxycholic- and hyodeoxycholic acid were reduced with all types of guar gum independent of chain length. Differences in BA composition between pectin groups were less obvious, but cecal levels of α- and ω-muricholic acids were higher in rats fed LM as compared to HM pectin or the control diet. The inflammatory marker LBP was downregulated in rats fed medium-MW guar gum and HM pectin; these two fibers decreased the cecal abundance of Oscillospira and an unclassified genus in Ruminococcaceae, and increased that of an unclassified family in RF32. These results indicate that the molecular properties of guar gum and pectin are important for their ability to modulate cecal BA formation, gut microbiota composition, and high-fat diet induced

  8. Potencial do soro de leite líquido como agente encapsulante de Bifidobacterium Bb-12 por spray drying: comparação com goma arábica Potential of liquid whey as the encapsulating agent of Bifidobacterium Bb-12 by spray drying: comparison with arabic gum

    Directory of Open Access Journals (Sweden)

    Fabiane Picinin de Castro-Cislaghi

    2012-09-01

    Full Text Available O objetivo do trabalho foi avaliar o potencial do soro de leite líquido como agente encapsulante de Bifidobacterium Bb-12 por spray drying, comparando-o com a goma arábica, a qual é tradicionalmente utilizada na tecnologia de microencapsulação. Foram determinados o rendimento da microencapsulação e a viabilidade das microcápsulas durante o armazenamento. Quando o soro de leite foi utilizado como agente encapsulante, o rendimento da microencapsulação foi maior e a viabilidade das células manteve-se elevada e constante durante doze semanas. O soro de leite apresentou-se como um eficiente agente encapsulante de Bifidobacterium por spray drying.The objective of this study was to evaluate the potential of liquid whey as the encapsulating agent Bifidobacterium Bb-12 by spray drying, compared with arabic gum, which is typically used in microencapsulation technology. The microencapsulation yield and viability during storage were determined. When the whey was used as the encapsulating agent, the microencapsulation yield was higher, and cell viability remained high and steady for twelve weeks. The whey was shown to be an effective encapsulating agent of Bifidobacterium by spray drying.

  9. Formulation development and evaluation of novel oral jellies of carbamazepine using pectin, guar gum, and gellan gum

    Directory of Open Access Journals (Sweden)

    Katakam Prakash

    2014-01-01

    Full Text Available Medicated jelly formulations are more suitable for pediatric, geriatric and dysphagic patients, which offer rapid dissolution and absorption of drugs thereby early onset of action. The aim was to develop and evaluate oral jelly formulations of carbamazepine (CBZ. Carbamazepine oral jellies were prepared to employ pectin, guar gum and gellan gum alone and pectin-guar gum combination. Preformulation studies, organoleptic, physical characteristics, drug content, pH, spreadability, rheological properties, syneresis, taste masking, in vitro dissolution testing, drug release kinetics and stability studies were conducted. The Fourier transform infrared and differential scanning calorimeter studies showed that there was no interaction between drug and excipients. The pH of all the formulations was found between pH 6.37 ± 0.03 and 6.83 ± 0.04. The concentration of gelling agents influenced the spreadability. Syneresis was observed in jellies made from guar gum alone, whereas those made from pectin and guar gum it was absent. The optimized formulations (F3, F11 and F15 masked the bitter taste of CBZ and demonstrated acceptable flavor and mouth feel. All formulations showed more than 50% drug release in 15 min except those made of gellan gum alone. The formulations F3, F11 and F15, were found stable for 90 days as per International Conference on Harmonization stability protocol. Carbamazepine jellies made from pectin (F3, 1.2%, gellan gum (F11, 1.5% and pectin-guar gum (F15, 1:0.4% were found more successful and could be employed to improve the palatability and acceptability by pediatric, geriatric and dysphagic patients. The jellies could be useful to overcome the problems of poorly soluble CBZ.

  10. GOMA - A full-Newton finite element program for free and moving boundary problems with coupled fluid/solid momentum, energy, mass, and chemical species transport: User`s guide

    Energy Technology Data Exchange (ETDEWEB)

    Schunk, P.R.; Sackinger, P.A.; Rao, R.R. [and others

    1996-01-01

    GOMA is a two- and three-dimensional finite element program which excels in analyses of manufacturing processes, particularly those involving free or moving interfaces. Specifically, the full-Newton-coupled heat, mass, momentum, and pseudo-solid mesh motion algorithm makes GOMA ideally suited for simulating processes in which the bulk fluid transport is closely coupled to the interfacial physics. Examples include, but are not limited to, coating and polymer processing flows, soldering, crystal growth, and solid-network or solution film drying. The code is based on the premise that any boundary can be (1) moving or free, with an apriori unknown position dictated by the distinguishing physics, (2) fixed, according to a global analytical representation, or (3) moving in time and space under user-prescribed kinematics. The goal is to enable the user to predict boundary position or motion simultaneously with the physics of the problem being analyzed and to pursue geometrical design studies and fluid-structure interaction problems. The moving mesh algorithm treats the entire domain as a computational Lagrangian solid that deforms subject to the physical principles which dictate boundary position. As an added benefit, the same Lagrangian solid mechanics can be exploited to solve multi-field problems for which the solid motion and stresses interact with other transport phenomena, either within the same material phase (e.g. shrinking coating) or in neighboring material phases (e.g. flexible blade coating). Thus, analyses of many fluid-structure interaction problems and deformable porous media problems are accessible. This document serves as a user`s guide and reference for GOMA and provides a brief overview of GOMA`s capabilities, theoretical background, and classes of problems for which it is targeted.

  11. OTIMIZAÇÃO DE UM SISTEMA ESTABILIZANTE PARA O “IOGURTE” DE SOJA

    Directory of Open Access Journals (Sweden)

    ELIZEU ANTONIO ROSSI

    2009-07-01

    Full Text Available

    RESUMO: Com um propósito de obter um “iogurte” de soja com textura e aceitabilidade adequadas, 15 formulações com diferentes proporções de gelatina, goma guar e goma xantana foram estudadas pela metodologia de superfície de resposta, visando estabelecer um sistema otimizado. Em cada um dos casos, as amostras tiveram a viscosidade e a consistência determinadas e foram também submetidas a um painel sensorial constituído por 8 membros treinados. Os resultados mostraram que é possível obter um produto com textura otimizada e alta aceitabilidade empregando-se gelatina, goma guar e goma xantana nas proporções e 1,27; 2,32 e 0,19 g/1, respectivamente. O uso da metodologia de superfície de resposta também permitiu estabelecer modelos matemáticos preditivos para textura e aceitabilidade geral. PALAVRAS-CHAVE: Soja-fermentados; iogurte-estabilizantes.

  12. Partially hydrolyzed guar gum affects the expression of genes involved in host defense functions and cholesterol absorption in colonic mucosa of db/db male mice.

    Science.gov (United States)

    Yasukawa, Zenta; Naito, Yuji; Takagi, Tomohisa; Mizushima, Katsura; Tokunaga, Makoto; Ishihara, Noriyuki; R Juneja, Lekh; Yoshikawa, Toshikazu

    2012-07-01

    Biomedical evidence in the last 20 years has shown that the consumption of partially hydrolyzed guar gum may influence lipid and/or carbohydrate metabolism at many levels. Since intestine represents the first interface to interact with dietary partially hydrolyzed guar gum in vivo, we evaluated gene expression profiles in small intestinal mucosa of db/db mice fed with partially hydrolyzed guar gum in an effort to delineate its effect on the small intestine. DNA microarray and real-time PCR analyses were performed to evaluate the gene expression profiles in mice small intestinal mucosa. Among the 28,853 transcripts represented on the GeneChip® microarray, no more than 20 genes exhibited up- or down-regulation by 1.5-fold or more after four weeks following partially hydrolyzed guar gum consumption. No adverse effects were apparent. We detected up- or down-regulation of some genes known to be involved in host defense functions and cholesterol absorption.

  13. Semi-dilute galactomannan solutions: observations on viscosity scaling behavior of guar gum

    Science.gov (United States)

    Pollard, Michael A.; Fischer, Peter

    2014-11-01

    Based on experimental work involving evaluation of viscosity enhancement of aqueous solutions by high molecular weight guar gum, we have observed that the shear viscosity scaling exponent b for semi-dilute solutions, ηsp ˜ (c[η])b, is sensitive to molecular weight, being approximately 4.7 for native samples and decreasing progressively as Mw is lowered. The critical overlap parameter demarcating the dilute and semi-dilute regimes also depends on the molecular weight as {{≤ft(c[η ]\\right)}*} ˜ Mw-0.82 . Consequently, viscosity-concentration plots fail to achieve overlap using only specific viscosity and overlap concentration as reducing variables, a commonly accepted empiricism for random-coil polysaccharides. To bridge the gap, we propose to account for water solubility, its temperature dependence and the resulting chain flexibility as additional factors to fully describe the solution behavior of these highly-important raw materials.

  14. A thixotropic hydrogel from chemically cross-linked guar gum: synthesis, characterization and rheological behaviour.

    Science.gov (United States)

    Barbucci, Rolando; Pasqui, Daniela; Favaloro, Roberto; Panariello, Giuseppe

    2008-12-08

    Polysaccharide guar gum (GG) was cross-linked in an alkaline solution with polyethylene glycol diglycidyl ether (PEGDGE) to create a new hydrogel. The GG hydrogel was examined by FT-IR spectroscopy, AFM analysis and SEM analysis. The water uptake of the GG hydrogel was measured at different pHs, and rheological studies were performed to verify the thixotropic nature of the material. Rheological studies revealed the pseudoplastic behaviour of the GG hydrogel and its thixotropic nature. AFM analysis on a sample which was subjected to shear stress showed the presence of nanoparticles in the hydrogel. When the sample was left to settle, the gel surface returned to its original homogenous morphology. The thixotropic and injectable nature of the GG hydrogel suggest its possible use in biomedical applications.

  15. Dynamic and steady: shear rheological properties of xanthan and guar gums dispersed in yellow passion fruit pulp (Passiflora edulis f. flavicarpa

    Directory of Open Access Journals (Sweden)

    I. C. F Moraes

    2011-09-01

    Full Text Available Yellow passion fruit pulp is unstable, presenting phase separation that can be avoided by the addition of hydrocolloids. For this purpose, xanthan and guar gum [0.3, 0.7 and 1.0% (w/w] were added to yellow passion fruit pulp and the changes in the dynamic and steady - shear rheological behavior evaluated. Xanthan dispersions showed a more pronounced pseudoplasticity and the presence of yield stress, which was not observed in the guar gum dispersions. Cross model fitting to flow curves showed that the xanthan suspensions also had higher zero shear viscosity than the guar suspensions, and, for both gums, an increase in temperature led to lower values for this parameter. The gums showed different behavior as a function of temperature in the range of 5 - 35ºC. The activation energy of the apparent viscosity was dependent on the shear rate and gum concentration for guar, whereas for xanthan these values only varied with the concentration. The mechanical spectra were well described by the generalized Maxwell model and the xanthan dispersions showed a more elastic character than the guar dispersions, with higher values for the relaxation time. Xanthan was characterized as a weak gel, while guar presented a concentrated solution behavior. The simultaneous evaluation of temperature and concentration showed a stronger influence of the polysaccharide concentration on the apparent viscosity and the G' and G" moduli than the variation in temperature.

  16. Pressure-controlled injection of guar gum stabilized microscale zerovalent iron for groundwater remediation.

    Science.gov (United States)

    Luna, M; Gastone, F; Tosco, T; Sethi, R; Velimirovic, M; Gemoets, J; Muyshondt, R; Sapion, H; Klaas, N; Bastiaens, L

    2015-10-01

    The paper reports a pilot injection test of microsized zerovalent iron (mZVI) dispersed in a guar gum shear thinning solution. The test was performed in the framework of the EU research project AQUAREHAB in a site in Belgium contaminated by chlorinated aliphatic hydrocarbons (CAHs). The field application was aimed to overcome those critical aspects which hinder mZVI field injection, mainly due to the colloidal instability of ZVI-based suspensions. The iron slurry properties (iron particles size and concentration, polymeric stabilizer type and concentration, slurry viscosity) were designed in the laboratory based on several tests (reactivity tests towards contaminants, sedimentation tests and rheological measurements). The particles were delivered into the aquifer through an injection well specifically designed for controlled-pressure delivery (approximately 10 bars). The well characteristics and the critical pressure of the aquifer (i.e. the injection pressure above which fracturing occurs) were assessed via two innovative injection step rate tests, one performed with water and the other one with guar gum. Based on laboratory and field preliminary tests, a flow regime at the threshold between permeation and preferential flow was selected for mZVI delivery, as a compromise between the desired homogeneous distribution of the mZVI around the injection point (ensured by permeation flow) and the fast and effective injection of the slurry (guaranteed by high discharge rates and injection pressure, resulting in the generation of preferential flow paths). A monitoring setup was designed and installed for the real-time monitoring of relevant parameters during injection, and for a fast determination of the spatial mZVI distribution after injection via non-invasive magnetic susceptibility measurements.

  17. Goma o absceso tuberculoso metastásico como diagnóstico inicial de tuberculosis en un paciente inmunocompetente: una presentación inusual

    Directory of Open Access Journals (Sweden)

    A. Marco

    2014-10-01

    Full Text Available Fundamento y Objetivo: Los abscesos fríos tuberculosos o gomas son inusuales y producto de la diseminación hematógena de micobacterias latentes, formando abscesos en extremidades o tronco, generalmente sin compromiso de tejidos profundos.Se presenta un caso de goma como diagnóstico inicial de tuberculosis diseminada. Métodos: Caso estudiado en 2012 por los servicios médicos del centro penitenciario de Hombres de Barcelona y el Servicio de Medicina Interna del Hospital Consorci Sanitari de Terrassa. Se recogen los datos de la historia clínica, de los informes hospitalarios y de las pruebas complementarias practicadas. Resultados: Preso, 35 años, de Cabo Verde, residente en España desde los 4 años. IDR Mantoux positiva. Inmunocompetente. Por síndrome constitucional se programó estudio hospitalario. Exploración anodina, excepto palpación de masa en región lumbar. La punción aspirativa fue positiva para M. tuberculosis mediante PCR y cultivo Lowenstein. La TC mostró nódulos pulmonares, apical D cavitado y en LSD. Tras aislamiento respiratorio, tratamiento antituberculoso y excelente evolución fue dado de alta con diagnóstico de tuberculosis diseminada. Discusión: Se recomienda vigilar lesiones que, aunque infrecuentes, pueden ser secundarias a infección por M tuberculosis, especialmente en población inmunocomprometida y en inmigrantes procedentes de zonas hiperendémicas de tuberculosis.

  18. High Temperature Stable Separator for Lithium Batteries Based on SiO2 and Hydroxypropyl Guar Gum

    Science.gov (United States)

    Carvalho, Diogo Vieira; Loeffler, Nicholas; Kim, Guk-Tae; Passerini, Stefano

    2015-01-01

    A novel membrane based on silicon dioxide (SiO2) and hydroxypropyl guar gum (HPG) as binder is presented and tested as a separator for lithium-ion batteries. The separator is made with renewable and low cost materials and an environmentally friendly manufacturing processing using only water as solvent. The separator offers superior wettability and high electrolyte uptake due to the optimized porosity and the good affinity of SiO2 and guar gum microstructure towards organic liquid electrolytes. Additionally, the separator shows high thermal stability and no dimensional-shrinkage at high temperatures due to the use of the ceramic filler and the thermally stable natural polymer. The electrochemical tests show the good electrochemical stability of the separator in a wide range of potential, as well as its outstanding cycle performance. PMID:26512701

  19. High Temperature Stable Separator for Lithium Batteries Based on SiO2 and Hydroxypropyl Guar Gum

    Directory of Open Access Journals (Sweden)

    Diogo Vieira Carvalho

    2015-10-01

    Full Text Available A novel membrane based on silicon dioxide (SiO2 and hydroxypropyl guar gum (HPG as binder is presented and tested as a separator for lithium-ion batteries. The separator is made with renewable and low cost materials and an environmentally friendly manufacturing processing using only water as solvent. The separator offers superior wettability and high electrolyte uptake due to the optimized porosity and the good affinity of SiO2 and guar gum microstructure towards organic liquid electrolytes. Additionally, the separator shows high thermal stability and no dimensional-shrinkage at high temperatures due to the use of the ceramic filler and the thermally stable natural polymer. The electrochemical tests show the good electrochemical stability of the separator in a wide range of potential, as well as its outstanding cycle performance.

  20. Glycaemic and insulin responses of diabetic patients to traditional Malaysian meals and the effect of guar gum.

    Science.gov (United States)

    Khalid, B A; Lee, L F; Samad, A H; Ng, M L

    1996-12-01

    The aims of the project were to determine the glycaemic and insulin responses of non-insulin dependent diabetic patients (NIDDM) to 3 traditional Malaysian meals compared to oral glucose, and to determine whether guar gum would affect these responses. Patients with NIDDM were tested with 75 g oral glucose and three common breakfast meals of the three main ethnic groups of Malaysia. When compared with the oral glucose group, significantly by lower blood glucose responses were seen at 90 and 120 minutes post prandial for nasi lemak (pnasi lemak and between 15 and 30 minutes (p<0.03) for mee sup but not with roti telur. With addition of guar gum, there was no significant change of insulin responses with the three meals but a significant increase was seen at 30 minutes (p<0.02) after ingestion of glucose.

  1. Preparation of C-GG modified guar gum%C-GG型改性瓜胶的制备

    Institute of Scientific and Technical Information of China (English)

    田跃儒; 宋爱莉; 周际永; 熊俊杰; 安琦; 斯旭

    2012-01-01

    天然瓜尔胶粉与醚化剂在乙醇溶液中反应,制备C-GG改性瓜尔胶,考察了反应物料比、反应时间、反应温度等对产品性能的影响.结果表明,合成C-GG改性瓜尔胶的最佳制备条件为:瓜尔胶粉:氢氧化钠:3-氯-2-羟丙基三甲基氯化铵为1:0.2:0.06,反应温度为70℃,反应时间为3h.在最佳反应条件下,得到产品的性能符合标准,粘度达到3650 mPa·s,取代度为0.224.%The C-GG modified guar gum was prepared by reacting guar gum with 3-chloro-2-hydroxypropyl trimethylammonium chloride. The effects of some factors such as the proportion of materials,reaction time, reaction temperature were studied and the proper conditions were determined. The results showed that the best preparation conditions for the synthesis of C-GG modified guar gum were as follows: guar gum powder: sodium hydroxide: 3-chloro-2-hydroxypropyl trimethylammonium chloride is 1:0. 2:0. 06, reac-tion temperature at 70℃ ,and reaction time for 3 h. Under the optimum reaction conditions, get the per-formance of products meet the stand, the viscosity was 3 650 mPa·s and the substitution degree was 0. 224.

  2. In vitro drug release studies on guar gum-based colon targeted oral drug delivery systems of 5-fluorouracil.

    Science.gov (United States)

    Krishnaiah, Y S R; Satyanarayana, V; Dinesh Kumar, B; Karthikeyan, R S

    2002-08-01

    Intravenous administration of 5-fluorouracil for colon cancer therapy produces severe systemic side-effects due to its cytotoxic effect on normal cells. The broad objective of the present study was to develop novel tablet formulations for site-specific delivery of 5-fluorouracil to the colon without the drug being released in the stomach or small intestine using guar gum as a carrier. Fast-disintegrating 5-fluorouracil core tablets were compression coated with 60% (FHV-60), 70% (FHV-70) and 80% (FHV-80) of guar gum, and were subjected to in vitro drug release studies. The amount of 5-fluorouracil released from the compression-coated tablets in the dissolution medium at different time intervals was estimated by a HPLC method. Guar gum compression-coated tablets released only 2.5-4% of the 5-fluorouracil in simulated GI fluids. When the dissolution study was continued in simulated colonic fluids (4% w/v rat caecal content medium) the compression-coated FHV-60, FHV-70 and FHV-80 tablets released another 70, 55 and 41% of the 5-fluorouracil respectively. The results of the study show that compression-coated tablets containing 80% (FHV-80) of guar gum are most likely to provide targeting of 5-fluorouracil for local action in the colon, since they released only 2.38% of the drug in the physiological environment of the stomach and small intestine. The FHV-80 formulation showed no change either in physical appearance, drug content or dissolution pattern after storage at 40 degrees C/RH 75% for 6 months. The differential scanning calorimetric study showed that 5-fluorouracil did not interact with the formulation excipients used in the study.

  3. In vitro release characteristics of matrix tablets: Study of Karaya gum and Guar gum as release modulators

    Directory of Open Access Journals (Sweden)

    Senapati M

    2006-01-01

    Full Text Available Matrix tablets of phenylpropanolamine were fabricated using karaya gum and guar gum, alone or in combination with other excipients. The tablets were evaluated for physical characteristics like hardness, weight variation, friability, swelling index and drug content. In vitro release of drug was performed in 0.1N HCl (pH 1.2 for 2 h and the rest of dissolution in phosphate buffer (pH 6.8. The effect of water-soluble (lactose and water-insoluble (dicalcium phosphate excipients on drug release was evaluated. All the physical characteristics of the fabricated tablets were within acceptable limits. The tablets with karaya gum exhibited greater swelling indices than those with guar gum. All the batches provided drug release over a period of 6 h. The level of matrix former in the tablets affects drug release. Incorporation of lactose or dicalcium phosphate influenced drug release, but at lower polymer levels only. A combination of karaya gum and guar gum exhibited more sustained release than individual gum.

  4. 干法制阳离子瓜尔胶%The Study on the Dry Preparation of Cationic Guar Gum

    Institute of Scientific and Technical Information of China (English)

    贺小兰; 朱进; 邓勋民

    2012-01-01

    目前我国阳离子瓜儿胶工业化生产大都采用传统的湿法生产,湿法生产瓜尔胶存在需大量的有机溶剂,劳动强度大、能耗高、安全风险高、生产成本高等问题。本实验采用干法研制瓜尔胶,改变传统工艺。确定干法生产瓜尔胶最佳工艺配方及工艺条件,以确定产品最优成本,达到最大经济利益。%At present, cationic guar gum mostly use the traditional wet preparauon m muusmat prouucuul, in China. Wet preparation of guar gum has some disadvantages, such as required large amounts of organic solvents, high labor intensity, high energy consumption, high safety risk, higher production costs, etc. Tthe method of dry preparation of guar gum instead of the traditional process was reported. Through the experiment, we found out the optimum formulation and conditions of this method to make sure the optimal product costs and achieve maximum economic benefits.

  5. Effect of partially hydrolyzed guar gum on pasting, thermo-mechanical and rheological properties of wheat dough.

    Science.gov (United States)

    Mudgil, Deepak; Barak, Sheweta; Khatkar, B S

    2016-12-01

    Partially hydrolyzed guar gum was prepared using enzymatic hydrolysis of native guar gum that can be utilized as soluble fiber source. The effect of partially hydrolyzed guar gum (PHGG) on pasting, thermo-mechanical and rheological properties of wheat flour was investigated using rapid visco-analyzer, Mixolab and Microdoughlab. Wheat flour was replaced with 1-5g PHGG per 100g of wheat flour on weight basis. PHGG addition decreased the peak, trough, breakdown, setback and final viscosity of wheat flour. Water absorption and amylase activity of wheat dough were increased whereas starch gelatinization and protein weakening of wheat dough were reduced as a result of PHGG addition to wheat flour. PHGG addition also increased the peak dough height, arrival time, dough development time, dough stability and peak energy of wheat dough system. However, dough softening was decreased after PHGG addition to wheat flour dough. Overall, it can be assumed that PHGG has influenced the properties of wheat flour dough system by decreasing the RVA viscosities and increasing the water absorption and starch gelatinization of wheat dough system.

  6. Research the printing properties of the modified guar gum%改性瓜尔豆胶印花性能探讨

    Institute of Scientific and Technical Information of China (English)

    李林; 黄小华; 卢殿光

    2011-01-01

    对改性瓜尔豆胶和海藻酸钠印花糊料的各项性能及其用于棉织物活性染料印花效果进行对比.实验表明,改性瓜尔豆胶的成糊率较高,其PVI值比海藻酸钠印花糊料PVI值低,粘度较大,更接近平网印花对糊料粘度的要求,且印花织物具有较好耐摩擦、耐水洗性能;改性瓜尔豆胶糊料其印花织物的K/S值与海藻酸钠糊料的印花织物相接近.因此,使用改性瓜尔豆胶可以部分替代海藻酸钠作为印花糊料,以降低生产成本.%The effects of reactive dyes printing between modified guar gum and sodium alginates were compared on the cotton fabrics including a variety of their properties tested.Experiments indicate that modified guar gum has high rate of paste,the PVI value of modified guar gum is lower than sodium alginates's,cotton fabrics useing modified guar gum has better friction and wash property,and modified guar gum's viscosity are close to the plate scream printing of paste viscosity request;the cotton fabrics's K/S with modified guar gum are similar to the cotton fabrics's K/S with sodium alginates.Therefore,sodium alginates can be replaced by the modified guar gum as printing paste,so as to reduce the production cost.

  7. Folic acid conjugated guar gum nanoparticles for targeting methotrexate to colon cancer.

    Science.gov (United States)

    Sharma, Monika; Malik, Ritu; Verma, Ashwni; Dwivedi, Pankaj; Banoth, Gabbar Singh; Pandey, Nagendra; Sarkar, Jayant; Mishra, Prabhat Ranjan; Dwivedi, Anil Kumar

    2013-01-01

    It was envisaged to develop surface modified Guar Gum Nanoparticles (GGNP) with Folic acid (FA) charged with methotrexate (MTX) to target the colon specifically. The MTX loaded FA functionalized GGNP (MTX-FA-GGNP) have been prepared by emulsion crosslinking method. These surface modified nanoparticles were compared with unmodified MTX loaded GGNP (MTX-GGNP). The developed formulations were evaluated for size and size distribution, zeta potential, Differential Scanning Calorimetry (DSC), release profile and uptake studies. The nanoparticles have been found to have average size of 325 nm in diameter having polydispersity index (PDI) 0.177 indicating mono-disperse particles. The zeta potential of the particles was found to be -36.9 mV. The percent growth inhibition of Caco 2 cells with MTX-FA-GGNP was found to be better than MTX-GGNP indicating folate receptor mediated uptake. The MTX-GGNP protects the release of MTX in upper gastrointestinal tract while maximum release of MTX occurred in simulated colonic fluids of pH 6.8. The in vivo uptake studies revealed preferential uptake of nanoparticles formulation in the colon. These studies provide evidences that MTX-FA-GGNP holds promise to address colorectal cancer over-expressing folate receptors. This prototype formulation enjoys dual advantage of having propensity to release the drug in the colon and in the conditions of colorectal carcinoma; it could be better localized and targeted with improved therapy due to over-expression of folate receptors.

  8. Adsorptional removal of methylene blue by guar gum-cerium (IV) tungstate hybrid cationic exchanger.

    Science.gov (United States)

    Gupta, V K; Pathania, Deepak; Singh, Pardeep; Kumar, Amit; Rathore, B S

    2014-01-30

    Guar gum-cerium (IV) tungstate nanocomposite (GG/CTNC) cationic exchanger was synthesized using simple sol gel method. The GG/CTNC was characterized using X-ray diffraction (XRD), Fourier transmission infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and energy dispersive X-ray spectrophotometer (EDX). The XRD studies confirmed amorphous and fibrous in nature of GG/CTNC. The high percentage of oxygen in the nanocomposite material confirmed the functionality tungstate (WO4(-)). The ion exchange capacity of GG/CTNC for Na(+) ion was observed to be 1.30 mequivg(-1). The hybrid exchanger was used as potential adsorbent for the removal of methylene blue (MB) from aqueous system. The correlation coefficients value indicated a good fit of monolayer Langmuir model to the adsorption of methylene blue onto GG/CTNC. The adsorption kinetic study revealed that the adsorption process followed the pseudo second order kinetic. The Gibbs free energy (ΔG) values confirmed the spontaneous nature of adsorption process.

  9. INCORPORATION AND RELEASE KINETICS OF ALPHA-BISABOLOL FROM PCL AND CHITOSAN/GUAR GUM MEMBRANES

    Directory of Open Access Journals (Sweden)

    F. C. Bombaldi de Souza

    Full Text Available Abstract Alpha-bisabolol, an anti-inflammatory and antioxidant compound extracted from candeia trees (Eremanthus erythropappus, was incorporated into hydrophobic polycaprolactone (PCL and hydrophilic chitosan/guar gum (Ch-G membranes aiming at the production of bioactive wound dressings. The incorporation efficiency achieved a maximum of ca. 18% (1 gram of alpha-bisabolol per gram of membrane for Ch-G membranes. For PCL membranes, all of the active compound added was retained (0.2 gram of alpha-bisabolol per gram of membrane. Alpha-bisabolol release in phosphate-buffered saline was relatively slow in both cases, reaching around 6% and 24% after 120 hours respectively for PCL and Ch-G membranes presenting equivalent initial alpha-bisabolol/membrane mass ratios. Both formulations were capable of releasing alpha-bisabolol in the typically recommended topical dose range (from 1 to 10 grams of alpha-bisabolol per gram of vehicle. The extended release periods observed are advantageous, allowing less frequent dressing changes and contributing to turn the treatment more comfortable for the patient.

  10. Post-meal perceivable satiety and subsequent energy intake with intake of partially hydrolysed guar gum.

    Science.gov (United States)

    Rao, Theertham Pradyumna; Hayakawa, Mariko; Minami, Tadayasu; Ishihara, Noriyuki; Kapoor, Mahendra Parkash; Ohkubo, Tsutomu; Juneja, Lekh Raj; Wakabayashi, Kazuo

    2015-05-14

    Partially hydrolysed guar gum (PHGG), a soluble dietary fibre, has been shown to provide many health benefits. Previous studies had suggested that the combination of PHGG with protein provided a significant satiation effect on visual analogue scales (VAS). What was lacking was only the effect of administration of small doses of PHGG on post-meal satiation and subsequent energy intake. The objectives of the present investigations were to find the subjective perception of post-meal satiety with acute and long term administration of small amounts of PHGG alone with food, its effects on subsequent energy intake and the comparative effects among different types of soluble fibres. The following three separate studies were conducted: in study 1, healthy subjects (n 12) consumed PHGG along with breakfast, lunch and an evening snack; in study 2, healthy subjects (n 24) consumed 2 g of PHGG or dextrin along with yogurt as breakfast for 2 weeks; in study 3, healthy subjects (n 6) took 6 g each of either PHGG or indigestible dextrin or inulin along with lunch. In all the studies, various satiety parameters were measured on VAS before and after consumption of PHGG. The addition of PHGG showed significant (P satiety effects compared to the control and/or an equal amount of carbohydrate or other types of soluble fibre. Study 2 also indicated that the prolonged consumption of PHGG may significantly (P satiety effects for comfortable appetite control.

  11. Hydrophobic derivatives of guar gum hydrolyzate and gum Arabic as matrices for microencapsulation of mint oil.

    Science.gov (United States)

    Sarkar, Shatabhisa; Gupta, Sumit; Variyar, Prasad S; Sharma, Arun; Singhal, Rekha S

    2013-06-05

    Guar gum hydrolyzate (GGH) modified with n-octenyl succinic anhydride (OSA) and oleic acid having induced hydrophobicity was evaluated for encapsulation of mint oil and compared with gum Arabic (GA) and GA-OSA as wall material. Spray dried microcapsules prepared with these wall materials were evaluated for qualitative changes by principal component analysis and for percent retention of mint oil during 8-week storage. Results revealed that microcapsules with GGH-OSA and GGH-oleate showed slightly lower retention of mint oil as compared to GA. GA-OSA microcapsules showed better retention of mint oil than GA itself, as observed from the t1/2, the time required for the mint oil to come down to 50% of its original content. The t1/2 of mint oil in microcapsules of GA, GGH-oleate, GGH-OSA and GA-OSA was 26.12, 23.50, 24.11 and 29.67 weeks, respectively. The results suggested that GGH-OSA has the potential to replace gum Arabic for encapsulation of mint oil. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Effect of xanthan/enzyme-modified guar gum mixtures on the stability of whey protein isolate stabilized fish oil-in-water emulsions.

    Science.gov (United States)

    Chityala, Pavan Kumar; Khouryieh, Hanna; Williams, Kevin; Conte, Eric

    2016-12-01

    The effect of xanthan gum (XG) and enzyme-modified guar (EMG) gum mixtures on the physicochemical properties and oxidative stability of 2wt% whey protein isolate (WPI) stabilized oil-in-water (O/W) emulsions containing 20%v/v fish oil was investigated. EMG was obtained by hydrolyzing native guar gum using α-galactosidase enzyme. At higher gum concentrations (0.2 and 0.3wt%), the viscosity of the emulsions containing XG/EMG gum mixtures was significantly higher (Pgum mixtures did not affect the droplet size of emulsions. Microstructure images revealed decreased flocculation at higher concentrations. Primary and secondary lipid oxidation measurements indicated a slower rate of oxidation in emulsions containing XG/EMG gum mixtures, compared to XG, guar (GG), and XG/GG gum mixtures. These results indicate that XG/EMG gum mixtures can be used in O/W emulsions to increase physical and oxidative stabilities of polyunsaturated fatty acids in foods.

  13. 阳离子瓜儿胶季铵盐的制备及应用%Preparation and Application of Cationic Guar Gum Quaternary Ammonium Salt

    Institute of Scientific and Technical Information of China (English)

    孟小华

    2015-01-01

    通过对阳离子瓜尔胶的制备方法、影响因素及其在洗发香波中应用的研究,得到有机溶剂法制备阳离子瓜尔胶的最佳工艺条件如下:以异丙醇作溶剂,瓜尔胶用量10 g, CTA用量2.5 g,氢氧化钠用量0.8 g,在80℃下,持续反应9 h,所得阳离子瓜尔胶的取代度为0.075,反应效率为73%。1.0%的阳离子瓜尔胶可以使洗发香波的粘度由1650 mPa・ s增至8150 mPa・ s,洗发后使毛发显著变得柔软光滑。%This experiment has systematically studied preparation method of the cationic guar, the influence factor and the application of cationic guar gum in shampoo.The best process conditions of organic solvent preparation of cationic guar gum were as follows:using isopropyl alcohol as solvent, the amount of guar gum was 10 g, CTA dosage was 1.5 g, sodium hydroxide dosage was 0.8 g, reaction temperature was 80 ℃, time was 9 h, the degree of substitution of the cationic guar gum was 0.075 , the reaction efficiency was 73%.The 1.0%Cationic Guar may enable shampoo’viscosity from 1650 mPa・ s to 8150 mPa・ s, and after washed with it the hair was softer and smoother remarkable.

  14. 交联瓜尔胶制备工艺%Preparation of Cross-linked Guar Gum

    Institute of Scientific and Technical Information of China (English)

    唐洪波; 王习光; 李艳平

    2012-01-01

    以瓜尔胶为原料、环氧氯丙烷为交联剂、氢氧化钠为催化剂、乙醇为溶剂,对交联瓜尔胶的制备工艺进行研究。考察环氧氯丙烷用量、pH值、反应时间、反应温度和乙醇质量分数对交联瓜尔胶沉降积的影响。结果表明,环氧氯丙烷用量、pH值、反应时间、反应温度和乙醇质量分数对瓜尔胶交联反应均有影响。制备交联瓜尔胶的最佳工艺条件为交联剂环氧氯丙烷用量8%、pH值、反应时间3.5h、反应温度40℃、乙醇质量分数95%。瓜尔胶交联反应的影响主次顺序依次为环氧氯丙烷用量〉反应温度〉pH值〉反应时间〉乙醇质量分数。热分析表明,随着交联瓜尔胶交联度的增加,交联瓜尔胶的热稳定性、焓变、吸收峰起始温度、峰值温度和结束温度增加。%The preparation of cross-linked guar gum was investigated by using epichlorohydrin as the cross-linking agent, sodium hydroxide as the catalyst and ethanol as the solvent in this study. The effects of epichlorohydrin amount, pH, reaction time, reaction temperature and alcohol concentration on the sediment volume of cross-linked guar gum was explored. The results showed that epichlorohydrin amount, pH, reaction time, reaction temperature and alcohol concentration had obvious impact on cross-linked reaction of guar gum. The optimal conditions for preparing cross-linked guar gum were epichlorohydlin amount of 8%, reaction time of 3.5 h, reaction temperature of 40 ℃ and ethanol concentration of 95%. Five reaction conditions were ranked in decreasing order of their effect on the sediment volume of cross-linked guar gum as follows: epichlorohydrin amount, reaction temperature, pH, reaction time and alcohol concentration. The thermal stability, enthalpy change, endothermic onset temperature, peak temperature and final temperature of cross-linked guar gum increased with increasing degree of cross-linking.

  15. Solvents addition influence on the automotive gasoline gum formation; Influencia da adicao de solventes na formacao de goma em gasolinas automotivas

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Diocleciano P. dos; Teixeira, Leonardo Sena Gomes; Almeida, Selmo Queiroz; Pontes, Luiz Antonio Magalhaes; Vitor Sobrinho, Eledir; Guimaraes, Paulo Roberto Britto; Vianna, Regina Ferreira [Universidade Salvador - UNIFACS, Salvador, BA (Brazil). Dept. de Engenharia e Arquitetura]. E-mail: leonardoteixeira@unifacs.br

    2003-07-01

    The unlawful addition of hydrocarbons such as kerosene, thinner, turpentine and diesel oil to gasoline has been often observed in Brazil lately. This not only results in undeserved market advantage, but may also cause serious damage to the consumer and to the environment, since it may change several physicochemical properties of the fuel, reduce engine performance and increase fuel consumption. Among the former, some of the most important are the distillation curve, octane number and the tendency for gum formation. This contribution is concerned with the analysis of the influence of a number of commercially available hydrocarbons on the tendency for gum formation of gasoline. The analytical method used was ASTM D381, and results indicate that for some of the hydrocarbons tested there is a marked increase in gum formation, and in some cases may be higher than the limit specified by law. (author)

  16. Determinação da estrutura química do polissacarídeo das gomas de exsudatos de Vochysia tucanorum e Vochysia thyrosidea /

    OpenAIRE

    Wagner, Ricardo

    2007-01-01

    Orientador : Philip A.J. Gorin Co-orientador : Marcello Iacomini Tese (doutorado) - Universidade Federal do Paraná, Setor de Ciências Biológicas, Programa de Pós-Graduação em Bioquímica. Defesa: Curitiba, 2007 Inclui bibliografia

  17. Preparation and in vitro characterization of mucoadhesive hydroxypropyl guar microspheres containing amlodipine besylate for nasal administration.

    Science.gov (United States)

    Swamy, N G N; Abbas, Z

    2011-11-01

    Amlodipine besylate microspheres for intranasal administration were prepared with an aim to avoid first-pass metabolism, to achieve controlled blood level profiles and to improve therapeutic efficacy. Hydroxypropyl Guar, a biodegradable polymer, was used in the preparation of microspheres by employing water in oil emulsification solvent evaporation technique. The formulation variables were drug concentration, emulsifier concentration, temperature, agitation speed and polymer concentration. All the formulations were evaluated for particle size, particle shape and surface morphology by scanning electron microscopy, percentage yield, drug entrapment efficiency, in vitro mucoadhesion test, degree of swelling and in vitro drug diffusion through sheep nasal mucosa. The microspheres obtained were free flowing, spherical and the particles ranged in size from 13.4±2.38 μm to 43.4±1.92 μm very much suitable for nasal delivery. Increasing polymer concentration resulted in increased drug entrapment efficiency and increased particle size. Amlodipine besylate was entrapped into the microspheres with an efficiency of 67.2±1.18 % to 81.8±0.64 %. The prepared microspheres showed good mucoadhesion properties, swellability and sustained the release of the drug over a period of 8 h. The data obtained were analysed by fitment into various kinetic models; it was observed that the drug release was matrix diffusion controlled and the release mechanism was found to be non-Fickian. Stability studies were carried out on selected formulations at 5±3°, 25±2°/60±5% RH and 40±2°/75±5% RH for 90 days. The drug content was observed to be within permissible limits and there were no significant deviations in the in vitro mucoadhesion and in vitro drug diffusion characteristics.

  18. Preparation and in vitro characterization of mucoadhesive hydroxypropyl guar microspheres containing amlodipine besylate for nasal administration

    Directory of Open Access Journals (Sweden)

    N. G. N. Swamy

    2011-01-01

    Full Text Available Amlodipine besylate microspheres for intranasal administration were prepared with an aim to avoid first-pass metabolism, to achieve controlled blood level profiles and to improve therapeutic efficacy. Hydroxypropyl Guar, a biodegradable polymer, was used in the preparation of microspheres by employing water in oil emulsification solvent evaporation technique. The formulation variables were drug concentration, emulsifier concentration, temperature, agitation speed and polymer concentration. All the formulations were evaluated for particle size, particle shape and surface morphology by scanning electron microscopy, percentage yield, drug entrapment efficiency, in vitro mucoadhesion test, degree of swelling and in vitro drug diffusion through sheep nasal mucosa. The microspheres obtained were free flowing, spherical and the particles ranged in size from 13.4±2.38 μm to 43.4±1.92 μm very much suitable for nasal delivery. Increasing polymer concentration resulted in increased drug entrapment efficiency and increased particle size. Amlodipine besylate was entrapped into the microspheres with an efficiency of 67.2±1.18 % to 81.8±0.64 %. The prepared microspheres showed good mucoadhesion properties, swellability and sustained the release of the drug over a period of 8 h. The data obtained were analysed by fitment into various kinetic models; it was observed that the drug release was matrix diffusion controlled and the release mechanism was found to be non-Fickian. Stability studies were carried out on selected formulations at 5±3° , 25±2° /60±5% RH and 40±2° /75±5% RH for 90 days. The drug content was observed to be within permissible limits and there were no significant deviations in the in vitro mucoadhesion and in vitro drug diffusion characteristics.

  19. Nanostructured SnO2 encapsulated guar-gum hybrid nanocomposites for electrocatalytic determination of hydrazine.

    Science.gov (United States)

    Malik, Priya; Srivastava, Manish; Verma, Ranjana; Kumar, Manish; Kumar, D; Singh, Jay

    2016-01-01

    The present article deals with synthesis of sol-gel derived tin dioxide (SnO2) nanoparticles encapsulated in to guar gum (GG) biopolymer as the organic-inorganic hybrid materials for the determination of hydrazine. The organic-inorganic hybrid combines the perfunctory strength offered by the inorganic SnO2 nanoparticles with flexible binding sites provided by the organic biopolymer (GG) solution by the ultrasonication. The phase identification, crystalline size, surface morphology and optical properties of prepared SnO2 and SnO2-GG nanocomposites has been investigated through FT-IR, XRD, SEM, AFM, TEM, UV-Vis, and PL techniques. The colloidal solution of SnO2 and GG is electrophoretically deposited (EPD) onto the indium tin-oxide (ITO) glass substrate and studied for the electrooxidation of hydrazine. Under the optimized experimental conditions, the linearity between the current response and the hydrazine concentration has been obtained in the range of 2-22 mM, with a low detection limit of 2.76 mM and a high sensitivity of 5.72 μA cm(-2). Based on the linear increase in amperometric current, a sensitive hydrazine electrochemical sensor is constructed. The proposed SnO2-GG/ITO electrode shows a good response time (35s), reproducibility, and long-term stability. The obtained results suggest that SnO2-GG nanocomposites electrode provides a favorable sensing platform for the electrochemical studies. In addition, the cyclic voltammetry (CV) studies are used to evaluate the kinetic parameters.

  20. Protection against the Metabolic Syndrome by Guar Gum-Derived Short-Chain Fatty Acids Depends on Peroxisome Proliferator-Activated Receptor γ and Glucagon-Like Peptide-1.

    Science.gov (United States)

    den Besten, Gijs; Gerding, Albert; van Dijk, Theo H; Ciapaite, Jolita; Bleeker, Aycha; van Eunen, Karen; Havinga, Rick; Groen, Albert K; Reijngoud, Dirk-Jan; Bakker, Barbara M

    2015-01-01

    The dietary fiber guar gum has beneficial effects on obesity, hyperglycemia and hypercholesterolemia in both humans and rodents. The major products of colonic fermentation of dietary fiber, the short-chain fatty acids (SCFAs), have been suggested to play an important role. Recently, we showed that SCFAs protect against the metabolic syndrome via a signaling cascade that involves peroxisome proliferator-activated receptor (PPAR) γ repression and AMP-activated protein kinase (AMPK) activation. In this study we investigated the molecular mechanism via which the dietary fiber guar gum protects against the metabolic syndrome. C57Bl/6J mice were fed a high-fat diet supplemented with 0% or 10% of the fiber guar gum for 12 weeks and effects on lipid and glucose metabolism were studied. We demonstrate that, like SCFAs, also guar gum protects against high-fat diet-induced metabolic abnormalities by PPARγ repression, subsequently increasing mitochondrial uncoupling protein 2 expression and AMP/ATP ratio, leading to the activation of AMPK and culminating in enhanced oxidative metabolism in both liver and adipose tissue. Moreover, guar gum markedly increased peripheral glucose clearance, possibly mediated by the SCFA-induced colonic hormone glucagon-like peptide-1. Overall, this study provides novel molecular insights into the beneficial effects of guar gum on the metabolic syndrome and strengthens the potential role of guar gum as a dietary-fiber intervention.

  1. Protection against the Metabolic Syndrome by Guar Gum-Derived Short-Chain Fatty Acids Depends on Peroxisome Proliferator-Activated Receptor γ and Glucagon-Like Peptide-1.

    Directory of Open Access Journals (Sweden)

    Gijs den Besten

    Full Text Available The dietary fiber guar gum has beneficial effects on obesity, hyperglycemia and hypercholesterolemia in both humans and rodents. The major products of colonic fermentation of dietary fiber, the short-chain fatty acids (SCFAs, have been suggested to play an important role. Recently, we showed that SCFAs protect against the metabolic syndrome via a signaling cascade that involves peroxisome proliferator-activated receptor (PPAR γ repression and AMP-activated protein kinase (AMPK activation. In this study we investigated the molecular mechanism via which the dietary fiber guar gum protects against the metabolic syndrome. C57Bl/6J mice were fed a high-fat diet supplemented with 0% or 10% of the fiber guar gum for 12 weeks and effects on lipid and glucose metabolism were studied. We demonstrate that, like SCFAs, also guar gum protects against high-fat diet-induced metabolic abnormalities by PPARγ repression, subsequently increasing mitochondrial uncoupling protein 2 expression and AMP/ATP ratio, leading to the activation of AMPK and culminating in enhanced oxidative metabolism in both liver and adipose tissue. Moreover, guar gum markedly increased peripheral glucose clearance, possibly mediated by the SCFA-induced colonic hormone glucagon-like peptide-1. Overall, this study provides novel molecular insights into the beneficial effects of guar gum on the metabolic syndrome and strengthens the potential role of guar gum as a dietary-fiber intervention.

  2. Efeito de gomas de mascar contendo clorofenol / peróxido de hidrogênio, xilitol ou clorexidina no fluxo salivar, pH, capacidade tampão e escores salivares de Streptococcus mutans = Effects of chlorophenol / hydrogen peroxide versus xylitol or chlorhexidine as chewing gum on salivary flow rate, pH, buffer capacity and salivary Streptococcus mutans scores

    OpenAIRE

    Yévenes López, Ismael

    2014-01-01

    Objetivos: Gomas de mascar medicadas são preparações sólidas, de dose única, que devem ser mastigadas por um determinado período de tempo a fim de que um ou mais agentes farmacológicos sejam admnistrados. Neste contexto, gomas de mascar medicadas com três ingredientes farmacêuticos ativos cânfora, p-clorofenol e peróxido de hidrogênio foram avaliadas como agentes terapêuticos para cárie dentária. O objetivo deste estúdio foi comparar o efeito de gomas de mascar contendo chlorophenol / peróx...

  3. Photo-induced Synthesis and Characterization of Poly(methyl methacrylate) Grafted Sodium Salt of Partially Carboxymethylated Guar Gum

    Institute of Scientific and Technical Information of China (English)

    J.H.Trivedi; M.D.Thaker; H.C.Trivedi

    2014-01-01

    Photo-induced graft copolymerization of methyl methacrylate (MMA) onto sodium salt of partially carboxymethylated guar gum (Na-PCMGG,DS =0.291) was carried out in an aqueous medium using ceric ammonium nitrate (CAN) as photoinitiator to synthesize a novel graft copolymer,Na-PCMGG-g-PMMA,which may find its potential application as a metal adsorbent.The influences of synthesis variables such as concentrations of photoinitiator (CAN),nitric acid and monomer (MMA) as well as reaction time,temperature and amount of substrate on the grafting yields were studied and the reaction conditions for optimum photo-grafting were evaluated.At optimum concentration,the maximum values of the grafting yields achieved were G =271.61% and GE =63.89%.The experimental results were found to be in very good agreement with the proposed kinetic scheme.The photo-graft copolymerization of MMA onto Na-PCMGG (DS =0.291) was also carried out in the presence and absence of ultraviolet radiation for studying the efficiency of the photoinitiator.The influence of carboxymethyl groups introduced onto the guar gum molecules with regard to its behavior towards ultra-violet radiation induced grafting with MMA was also investigated.Photo-grafting process was confirmed and the products were characterized with the help of the spectroscopic (1H-NMR and FTIR) and SEM techniques.

  4. Synthesis, characterization and swelling properties of guar gum-g-poly(sodium acrylate-co-styrene)/muscovite superabsorbent composites

    Science.gov (United States)

    Wang, Wenbo; Kang, Yuru; Wang, Aiqin

    2010-04-01

    A series of novel guar gum-g-poly(sodium acrylate-co-styrene)/muscovite (GG-g-P(NaA-co-St)/MVT) superabsorbent composites were prepared by free-radical grafting copolymerization of natural guar gum (GG), partially neutralized acrylic acid (NaA), styrene (St) and muscovite (MVT) using ammonium persulfate (APS) as the initiator and N,N-methylene-bis-acrylamide (MBA) as the crosslinker. Optical absorption spectra confirmed that NaA and St had been grafted onto the GG main chain and MVT participated in the polymerization reaction. The simultaneous introduction of St and MVT into the GG-g-PNaA matrix could clearly improve the surface morphologies of the composites, and MVT led to better dispersion in the polymeric matrix without agglomeration, as revealed by electron microscopy. The effects of St and MVT on the water absorption and swelling behavior in various saline solutions, aqueous solutions of hydrophilic organic solvents and surfactant solutions were investigated. Results indicated that the swelling rate and capabilities of the composites were markedly enhanced by the incorporation of the hydrophobic monomer St and inorganic MVT clay mineral. The superabsorbent composite showed a clearer deswelling characteristic in solutions of multivalent saline, acetone and ethanol, and cationic surfactant than that in the solutions of multivalent saline, methanol and anionic surfactant.

  5. Novel cross linked guar gum-g-poly(acrylate) porous superabsorbent hydrogels: Characterization and swelling behaviour in different environments.

    Science.gov (United States)

    Chandrika, Ksv Poorna; Singh, Anupama; Rathore, Abhishek; Kumar, Anil

    2016-09-20

    A new series of eco-friendly cross linked guar gum-g-poly(acrylate) porous superabsorbent hydrogels was prepared by in situ grafting polymerization and cross-linking on to a natural guar gum employing N,N-methylene bis acrylamide as cross linker. Morphological and structural characterization of the prepared hydrogels (SPHs) done by Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and solid state C(13) NMR spectroscopy confirmed formation of porous grafted and crosslinked hydrogel structure. Increase in cross linker concentration in the feed mass exhibited decrease in porosity and increase in density of the hydrogels. Swelling of an optimized hydrogel (SPH) in response to external stimuli namely, salt solutions, fertilizer solutions, temperature, and pH exhibited high swelling ratios in various environments. Swelling rate of the SPH was faster than the corresponding nonporous superabsorbent hydrogel. The prepared hydrogels can serve as excellent carriers of pesticides, fertilizers and agriculturally important microbes. Biocontrol formulations based on a representative SPH exhibited excellent shelf-life characteristics and bioefficacy against phytopathogenic fungus Pythium aphanidermatum.

  6. Synthesis, characterization and swelling properties of guar gum-g-poly(sodium acrylate-co-styrene)/muscovite superabsorbent composites

    Energy Technology Data Exchange (ETDEWEB)

    Wang Wenbo; Kang Yuru; Wang Aiqin, E-mail: aqwang@licp.cas.c [Center for Eco-material and Green Chemistry, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)

    2010-04-15

    A series of novel guar gum-g-poly(sodium acrylate-co-styrene)/muscovite (GG-g-P(NaA-co-St)/MVT) superabsorbent composites were prepared by free-radical grafting copolymerization of natural guar gum (GG), partially neutralized acrylic acid (NaA), styrene (St) and muscovite (MVT) using ammonium persulfate (APS) as the initiator and N,N-methylene-bis-acrylamide (MBA) as the crosslinker. Optical absorption spectra confirmed that NaA and St had been grafted onto the GG main chain and MVT participated in the polymerization reaction. The simultaneous introduction of St and MVT into the GG-g-PNaA matrix could clearly improve the surface morphologies of the composites, and MVT led to better dispersion in the polymeric matrix without agglomeration, as revealed by electron microscopy. The effects of St and MVT on the water absorption and swelling behavior in various saline solutions, aqueous solutions of hydrophilic organic solvents and surfactant solutions were investigated. Results indicated that the swelling rate and capabilities of the composites were markedly enhanced by the incorporation of the hydrophobic monomer St and inorganic MVT clay mineral. The superabsorbent composite showed a clearer deswelling characteristic in solutions of multivalent saline, acetone and ethanol, and cationic surfactant than that in the solutions of multivalent saline, methanol and anionic surfactant.

  7. Synthesis, characterization and swelling properties of guar gum-g-poly(sodium acrylate-co-styrene/muscovite superabsorbent composites

    Directory of Open Access Journals (Sweden)

    Wenbo Wang, Yuru Kang and Aiqin Wang

    2010-01-01

    Full Text Available A series of novel guar gum-g-poly(sodium acrylate-co-styrene/muscovite (GG-g-P(NaA-co-St/MVT superabsorbent composites were prepared by free-radical grafting copolymerization of natural guar gum (GG, partially neutralized acrylic acid (NaA, styrene (St and muscovite (MVT using ammonium persulfate (APS as the initiator and N,N-methylene-bis-acrylamide (MBA as the crosslinker. Optical absorption spectra confirmed that NaA and St had been grafted onto the GG main chain and MVT participated in the polymerization reaction. The simultaneous introduction of St and MVT into the GG-g-PNaA matrix could clearly improve the surface morphologies of the composites, and MVT led to better dispersion in the polymeric matrix without agglomeration, as revealed by electron microscopy. The effects of St and MVT on the water absorption and swelling behavior in various saline solutions, aqueous solutions of hydrophilic organic solvents and surfactant solutions were investigated. Results indicated that the swelling rate and capabilities of the composites were markedly enhanced by the incorporation of the hydrophobic monomer St and inorganic MVT clay mineral. The superabsorbent composite showed a clearer deswelling characteristic in solutions of multivalent saline, acetone and ethanol, and cationic surfactant than that in the solutions of multivalent saline, methanol and anionic surfactant.

  8. Budesonide-Loaded Guar Gum Microspheres for Colon Delivery: Preparation, Characterization and in Vitro/in Vivo Evaluation

    Directory of Open Access Journals (Sweden)

    Ye Liu

    2015-01-01

    Full Text Available A novel budesonide (BUD colon delivery release system was developed by using a natural polysaccharide, guar gum. The rigidity of the microspheres was induced by a chemical cross-linking method utilizing glutaraldehyde as the cross-linker. The mean particle size of the microspheres prepared was found to be 15.21 ± 1.32 µm. The drug loading and entrapment efficiency of the formulation were 17.78% ± 2.31% and 81.6% ± 5.42%, respectively. The microspheres were spherical in shape with a smooth surface, and the size was uniform. The in vitro release profiles indicated that the release of BUD from the microspheres exhibited a sustained release behavior. The model that fitted best for BUD released from the microspheres was the Higuchi kinetic model with a correlation coefficient r = 0.9993. A similar phenomenon was also observed in a pharmacokinetic study. The prolongation of the half-life (t1/2, enhanced residence time (mean residence time, MRT and decreased total clearance (CL indicated that BUD microspheres could prolong the acting time of BUD in vivo. In addition, BUD guar gum microspheres are thought to have the potential to maintain BUD concentration within target ranges for a long time, decreasing the side effects caused by concentration fluctuation, ensuring the efficiency of treatment and improving patient compliance by reducing dosing frequency. None of the severe signs, like the appearance of epithelial necrosis and the sloughing of epithelial cells, were detected.

  9. Protection against the Metabolic Syndrome by Guar Gum-Derived Short-Chain Fatty Acids Depends on Peroxisome Proliferator-Activated Receptor. and Glucagon-Like Peptide-1

    NARCIS (Netherlands)

    den Besten, Gijs; Gerding, Albert; van Dijk, Theo H.; Ciapaite, Jolita; Bleeker, Aycha; van Eunen, Karen; Havinga, Rick; Groen, Albert K.; Reijngoud, Dirk-Jan; Bakker, Barbara M.

    2015-01-01

    The dietary fiber guar gum has beneficial effects on obesity, hyperglycemia and hypercholesterolemia in both humans and rodents. The major products of colonic fermentation of dietary fiber, the short-chain fatty acids (SCFAs), have been suggested to play an important role. Recently, we showed that S

  10. Long term ingestion of a preload containing fructo-oligosaccharide or guar gum decreases fat mass but not food intake in mice.

    Science.gov (United States)

    Hadri, Zouheyr; Chaumontet, Catherine; Fromentin, Gilles; Even, Patrick C; Darcel, Nicolas; Bouras, Abdelkader Dilmi; Tomé, Daniel; Rasoamanana, Rojo

    2015-08-01

    Fermentable dietary fibre such as fructo-oligosaccharide and viscous dietary fibers such as guar gum and alginate affect energy homeostasis. The goal of this study was to compare the impact of long term intake of these three dietary fibers on food intake, meal pattern, body weight and fat accumulation in mice. Over a period of 3weeks, the mice were fed daily with a preload containing 32mg of fructo-oligosaccharide or alginate or 13mg of guar gum. Food intake and body weight were monitored weekly, while meal patterns, adiposity and the expression of hypothalamic neuropeptide genes were evaluated at the end of the study period. The 3 dietary fibers produced a similar decrease in total daily food intake (14 to 22%) at the end of the first week, and this effect disappeared over time. The 3 dietary fibers induced a slight variation in satiation parameters. Body weight and expression of hypothalamic neuropeptide genes were not affected by any of the treatment. Preload of fructo-oligosaccharide and guar gum induced a similar and substantial decrease in the development of adiposity (17% and 14%, respectively), while alginate had no effect. Our results demonstrate mainly that the inhibitory effect of dietary fiber on food intake is lost over time, and that guar gum limits fat storage.

  11. Efectos de la inclusión de máquina isoinercial en el tratamiento del hombro del nadador con gomas elásticas. Ensayo aleatorizado controlado doble ciego

    OpenAIRE

    Sarabia Marañón, Elsa

    2014-01-01

    RESUMEN: Contexto: Las lesiones de hombro son comunes en los nadadores debido a las demandas del deporte. Los desequilibrios musculares son frecuentes debido a la biomecánica del deporte, que predispone los nadadores a la lesión. A día de hoy, no ha sido establecido un tratamiento con contracción concéntrica-excéntrica basada en máquina isoinercial. Objetivo: Determinar la efectividad de un programa de intervención de refuerzo con gomas elásticas cuando se añade también el trab...

  12. Study on synthesis of zwitterionic guar gum containing.sulfobetaine%磺酸甜菜碱两性离子瓜尔胶的合成研究

    Institute of Scientific and Technical Information of China (English)

    杜国勇; 陈国平

    2012-01-01

    A way for synthesis of zwitterionic guar gum containing sulfobetaine from epichlorohydrin, sodium bisulfite, dimethylamine and guar gum was designed. IR was used to characterize the sulfobetaine zwitterionic intermediate compound and zwitterionic guar gum containing sulfobetaine. The effects of reaction temperature, reaction time and the dosages of NaOH and etherifying agent on the substituting degree were investigated and the optimal conditions were determined as follows: reaction temperature of 70℃, time of 5 hours, mass ratio of NaOH to guar gum of 0.09 and mass ratio of etherifying agent to guar gum of 0.5.%设计了以环氧氯丙烷、亚硫酸氢钠、二甲胺和瓜尔胶为原料合成磺酸甜菜碱两性离子瓜尔胶的路线;并用红外对磺酸甜菜碱两性离子中间体和磺酸甜菜碱两性离子瓜尔胶进行了表征.考察了氢氧化钠和醚化剂用量、反应温度以及反应时间对取代度的影响,得到的最优条件是反应温度70℃、时间5h、氢氧化钠/瓜尔胶质量比为0.09和醚化剂/瓜尔胶质量比为0.5.

  13. The short-chain fatty acid uptake fluxes by mice on a guar gum supplemented diet associate with amelioration of major biomarkers of the metabolic syndrome.

    Science.gov (United States)

    den Besten, Gijs; Havinga, Rick; Bleeker, Aycha; Rao, Shodhan; Gerding, Albert; van Eunen, Karen; Groen, Albert K; Reijngoud, Dirk-Jan; Bakker, Barbara M

    2014-01-01

    Studies with dietary supplementation of various types of fibers have shown beneficial effects on symptoms of the metabolic syndrome. Short-chain fatty acids (SCFAs), the main products of intestinal bacterial fermentation of dietary fiber, have been suggested to play a key role. Whether the concentration of SCFAs or their metabolism drives these beneficial effects is not yet clear. In this study we investigated the SCFA concentrations and in vivo host uptake fluxes in the absence or presence of the dietary fiber guar gum. C57Bl/6J mice were fed a high-fat diet supplemented with 0%, 5%, 7.5% or 10% of the fiber guar gum. To determine the effect on SCFA metabolism, 13C-labeled acetate, propionate or butyrate were infused into the cecum of mice for 6 h and the isotopic enrichment of cecal SCFAs was measured. The in vivo production, uptake and bacterial interconversion of acetate, propionate and butyrate were calculated by combining the data from the three infusion experiments in a single steady-state isotope model. Guar gum treatment decreased markers of the metabolic syndrome (body weight, adipose weight, triglycerides, glucose and insulin levels and HOMA-IR) in a dose-dependent manner. In addition, hepatic mRNA expression of genes involved in gluconeogenesis and fatty acid synthesis decreased dose-dependently by guar gum treatment. Cecal SCFA concentrations were increased compared to the control group, but no differences were observed between the different guar gum doses. Thus, no significant correlation was found between cecal SCFA concentrations and metabolic markers. In contrast, in vivo SCFA uptake fluxes by the host correlated linearly with metabolic markers. We argue that in vivo SCFA fluxes, and not concentrations, govern the protection from the metabolic syndrome by dietary fibers.

  14. The short-chain fatty acid uptake fluxes by mice on a guar gum supplemented diet associate with amelioration of major biomarkers of the metabolic syndrome.

    Directory of Open Access Journals (Sweden)

    Gijs den Besten

    Full Text Available Studies with dietary supplementation of various types of fibers have shown beneficial effects on symptoms of the metabolic syndrome. Short-chain fatty acids (SCFAs, the main products of intestinal bacterial fermentation of dietary fiber, have been suggested to play a key role. Whether the concentration of SCFAs or their metabolism drives these beneficial effects is not yet clear. In this study we investigated the SCFA concentrations and in vivo host uptake fluxes in the absence or presence of the dietary fiber guar gum. C57Bl/6J mice were fed a high-fat diet supplemented with 0%, 5%, 7.5% or 10% of the fiber guar gum. To determine the effect on SCFA metabolism, 13C-labeled acetate, propionate or butyrate were infused into the cecum of mice for 6 h and the isotopic enrichment of cecal SCFAs was measured. The in vivo production, uptake and bacterial interconversion of acetate, propionate and butyrate were calculated by combining the data from the three infusion experiments in a single steady-state isotope model. Guar gum treatment decreased markers of the metabolic syndrome (body weight, adipose weight, triglycerides, glucose and insulin levels and HOMA-IR in a dose-dependent manner. In addition, hepatic mRNA expression of genes involved in gluconeogenesis and fatty acid synthesis decreased dose-dependently by guar gum treatment. Cecal SCFA concentrations were increased compared to the control group, but no differences were observed between the different guar gum doses. Thus, no significant correlation was found between cecal SCFA concentrations and metabolic markers. In contrast, in vivo SCFA uptake fluxes by the host correlated linearly with metabolic markers. We argue that in vivo SCFA fluxes, and not concentrations, govern the protection from the metabolic syndrome by dietary fibers.

  15. Pasting and Rheological Properties of Starch and Guar Gum Mixed Systems%淀粉与瓜尔豆胶复配体系糊化及流变特性研究

    Institute of Scientific and Technical Information of China (English)

    张雅媛; 顾正彪; 洪雁; 蔡旭冉

    2012-01-01

    This paper investigated the pasting and rheolgical properties of corn starch/guar gum and waxy corn starch/guar gum mixed systems. Moreover,the microstructures of starch/guar gum mixed systems were also observed by SEM. The results showed that the mixture pastes added with guar gum exhibited a more significant thickening effect and superior viscoelastic properties . The synergistic interaction was much more pronounced in corn starch/guar gum mixed systems. A decrease in the pasting temperature and behavior index of corn starch/guar gum mixed systems has been attributed to interactions between the guar gum molecules and amylose molecules. The SEM images showed the starch/guar gum mixed systems presented a more uniform and tight network.%以玉米淀粉和蜡质玉米淀粉为原料,加入不同配比的瓜尔豆胶,比较两者复配后糊化及流变特性的变化,并采用扫描电镜观察复配体系微观结构.结果表明:添加瓜尔豆胶可使玉米淀粉及蜡质玉米淀粉体系具有更好的增稠性,复配体系表现出更优越的黏弹性.胶体分子与直链淀粉分子间的相互作用是引起玉米淀粉与瓜尔豆胶复配体系流体指数和淀粉成糊温度显著降低,协同作用更为显著的主要原因.微观结构观察表明淀粉与胶体复配体系呈现出更加均一、紧凑的结构.

  16. A novel combination of plant growth regulators for in vitro regeneration of complete plantlets of guar [Cyamopsis tetragonoloba (L.) Taub].

    Science.gov (United States)

    Verma, S; Gill, K S; Pruthi, V; Dhugga, K S; Randhaw, G S

    2013-12-01

    A novel combination of plant growth regulators comprising indole-3-butyric acid (IBA), 6-benzylaminopurine (BA) and gibberellic acid (GA3) in Murashige and Skoog basal medium has been formulated for in vitro induction of both shoot and root in one culture using cotyledonary node explants of guar, (Cyamopsis tetragonoloba). Highest percentages of shoot (92%) and root (80%) induction were obtained in the medium containing (mg/L) 2 IBA, 3 BA and 1 GA3. Shoot regeneration from the cotyledonary node explants was observed after 10-15 days. Regeneration of roots from these shoots occurred after 20 to 25 days. The regenerated plantlets showed successful acclimatization on transfer to soil. This protocol is expected to be helpful in carrying out various in vitro manipulations in this economically and industrially important legume.

  17. Novel guar gum/Al2O3 nanocomposite as an effective photocatalyst for the degradation of malachite green dye.

    Science.gov (United States)

    Pathania, Deepak; Katwal, Rishu; Sharma, Gaurav; Naushad, Mu; Khan, Mohammad Rizwan; Al-Muhtaseb, Ala'a H

    2016-06-01

    Guar gum/Al2O3 (GG/AO) nanocomposite was prepared using simple and cost effective sol-gel method. This nanocomposite was characterized by several analytical techniques viz. scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), thermal analysis (TGA/DTA), Fourier transform infrared spectroscopy (FTIR) and ultraviolet-visible spectroscopy (UV-vis). The FTIR analysis confirmed that GG/AO composite material was formed. TEM images inferred the particle size in the range between 20 and 45nm. GG/AO nanocomposite exhibited good photocatalytic performance for malachite green (MG) dye (dye initial concentration 1.5×10(-5)M) degradation from aqueous phase. The adsorption followed by photocatalysis and coupled adsorption/photocatalysis reaction achieved about 80% and 90% degradation of MG dye under solar irradiation. Antibacterial test showed the excellent activity of GG/AO nanocomposite against Staphylococcus aureus.

  18. 羟丙基瓜尔胶的制备及表征%Preparation and characterization of hydroxypropyl guar gum

    Institute of Scientific and Technical Information of China (English)

    邹时英; 王克; 殷勤俭; 江波

    2004-01-01

    瓜尔胶(guar gum)是一种天然半乳甘露聚糖,其水溶性和增稠性很好,广泛用做增稠剂、破乳剂等。原粉胶溶解较慢、水不溶物含量高、粘度不易控制,人们常利用化学手段改变其理化特性以满足实际工业生产需要,羟丙基化是有效的手段之一,但对羟丙基化的表征较为困难。S.

  19. Effects of xanthan, guar, carrageenan and locust bean gum addition on physical, chemical and sensory properties of meatballs.

    Science.gov (United States)

    Demirci, Zeynep Ozben; Yılmaz, Ismail; Demirci, Ahmet Şukru

    2014-05-01

    This study evaluated the effects of xanthan gum, guar gum, carrageenan and locust bean gum on physical, chemical and sensory properties of meatballs. Meatball samples were produced with three different formulations including of 0.5, 1, and 1.5% each gum addition and gum added samples were compared with the control meatballs. Physical and chemical analyses were carried out on raw and cooked samples separately. Moisture contents of raw samples decreased by addition of gums. There were significant decreases (p gum when compared with control. Ash contents and texture values increased with gum addition to meatballs. Meatball redness decreased with more gum addition in raw and cooked meatball samples, which means that addition of gums resulted in a lighter-coloured product. According to sensory analysis results, locust bean gum added (1%) samples were much preferred by the panelists.

  20. Effect of guar gum and fiber-enriched wheat bran on gastric emptying of a semisolid meal in healthy subjects

    Energy Technology Data Exchange (ETDEWEB)

    Rydning, A.; Berstad, A.; Berstad, T.; Hertzenberg, L.

    1985-01-01

    The effect of physiological doses of guar gum (Guarem), 5 g, and fiber-enriched wheat bran (Fiberform), 10.5 g, on gastric emptying was studied by two different methods in healthy subjects: by a simple isotope localization monitor placed over the upper part of the abdomen, and by gamma camera. The fiber preparations were added to a semisolid meal consisting of wheatmeal porridge and juice, using technetium-99 DTPA as a marker. The gamma camera showed no effect of fiber on gastric emptying. The isotope localization monitor, however, indicated that Fiberform prevented postprandial accumulation of the meal within the upper part of stomach. The simple isotope localization monitor cannot be recommended for measurements of gastric emptying.

  1. Características físicas de dietas para peixes confeccionadas com diferentes aglutinantes Influence of agglutinants on physical stability of fish diets

    Directory of Open Access Journals (Sweden)

    Margarida Maria Barros

    2002-04-01

    Full Text Available Este experimento teve por objetivo avaliar a eficiência de diferentes aglutinantes, a seco e na água, por meio da estabilidade física do pélete. Foram avaliadas duas técnicas de processamento (com ou sem vapor e seis aglutinantes (carboximetilcelulose, polimetilcarbamida, amido de mandioca, alginato de sódio, polivinilpirrolidona, goma guar, através da análise de variância no esquema fatorial (2x6, além de um controle, ao qual não foi acrescido aglutinante. Concluiu-se que o aglutinante melhora significativamente a resistência física do grânulo, independente da técnica de processamento; que o vapor determina grânulos mais estáveis quando em contato com a água e, que o alginato de sódio proporciona grânulos fisicamente mais estáveis, em ambas as técnicas de processamento, enquanto a goma guar a pior.The aim of this paper was to determine the influence of different dry and water agglutinants, through physical stability of pellets. The agglutinants were sodium alginate, guar gum, polymetylcarbamide, polyvinylpirrolidone, carboxymetilcellulose, and cassava starch. The manufacturing processes were two: with and without steam and extrusion. These treatments were evaluated through the variance analysis technique with the factorial scheme 2 x 6 (two processes and six agglutinants, and one control where no extra agglutinants was added. Results showed that, independently of processing technique, the presence the agglutinants improves the physical resistance of the pellets significantly, giving the whole pellets more stability while in contact with water, and that the sodium alginate gives pellets the highest aggregated characteristic, in both processes, while that guar gum gives the lowest.

  2. Efeito de gomas de mascar contendo clorofenol / peróxido de hidrogênio, xilitol ou clorexidina no fluxo salivar, pH, capacidade tampão e escores salivares de Streptococcus mutans = Effects of chlorophenol / hydrogen peroxide versus xylitol or chlorhexidine as chewing gum on salivary flow rate, pH, buffer capacity and salivary Streptococcus mutans scores

    Directory of Open Access Journals (Sweden)

    Yévenes López, Ismael

    2014-01-01

    Full Text Available Objetivos: Gomas de mascar medicadas são preparações sólidas, de dose única, que devem ser mastigadas por um determinado período de tempo a fim de que um ou mais agentes farmacológicos sejam admnistrados. Neste contexto, gomas de mascar medicadas com três ingredientes farmacêuticos ativos – cânfora, p-clorofenol e peróxido de hidrogênio – foram avaliadas como agentes terapêuticos para cárie dentária. O objetivo deste estúdio foi comparar o efeito de gomas de mascar contendo chlorophenol / peróxido de hidrogênio, xilitol ou clorexidina sobre Streptococos mutans salivares, pH, capacidade tampão, a taxa de secreção salivar. Métodos: Foi realizado estudo duplo-cego, com deliamento de randomização cruzada de tratamento em 24 pacientes. Esses foram submetidos a seis sequências diferentes de tratamento. Gomas de mascar foram administradas três vezes ao dia durante 20 minutos, pela manhã, tarde e noite. No início e no final das três fases de amostras de saliva experimentais foram obtidas para a determinação de pH, capacidade tampão, fluxo salivar e enumeração quantitativa de S. mutans. Resultados: O uso de goma medicado de cânfora com p-clorofenol e peróxido de hidrogénio não modificaram os parâmetros químicos salivares medidos, e reduziram o número de S. mutans, após 7 dias. Gomas de mascar contendo clorexidina reduziram significativamente a contagem quantitativa de S. mutans e a taxa de fluxo salivar em um período de 7 dias. Conclusões: O uso de gomas de mascar medicadas com base de cânfora / p-clorofenol ou com peróxido de hidrogênio não altera significativamente os parâmetros químicos salivares e não reduz significativamente o número de S. mutans após a utilização por período de 7 dias

  3. Modification of Guar Gum and Study of Transmittance%瓜尔胶的改性及其透光性能研究

    Institute of Scientific and Technical Information of China (English)

    李聪暖; 罗儒显

    2012-01-01

    瓜尔豆片为原料,经羟丙基提纯后阳离子改性,得到透明性较好的阳离子瓜尔胶(CGG)。经分析碱法水解除蛋白质最优工艺为:豆片25g,NaOH5g,98℃下反应3h:蛋白质去除率为98.24%,透光率达77%。羟丙基化较优工艺为:环氧丙烷8mL。60℃反应4h;羟丙基取代度为0.2650,透光率为89%e阳离子化最优工艺为:醚化剂10mL,60℃反应3~5h,取代度(DS)为0.1701,透光率达97%。用IR对产蹦结构进行了表征,用TG和DSC对瓜尔胶、羟丙基瓜尔胶和阳离子瓜尔胶的对比研究表明,接枝的阳离子基团对瓜尔胶的相态稳定温度有影响,阳离予瓜尔胶的水分含量和结合水含量有所降低,利于储存。此产品用于对透光率要求较高的领域。%Cationic guar gum(CGG)with perfect transparency was obtained by hydroxypropyl purification and then cationization modification on guar gum. The discarding protein technology factors by alkaline process were provided as follows: the mass of splits and sodium hydroxide were 25 g and 5 g, respectively, reaction temperature was 98 ℃, reaction time was 3 h. The removal rate of protein was 98.24 %, the luminousness was 77 %. The synthetic process technology factors of hydroxypropyl guar gum were provided as follows: the volume of epoxy propane was 8 mL, reaction temperature and reaction time were 4 h and 60℃, respectively. The degree of substitution was 0.2650, the luminousness was 89 %. The optimal synthetic process technology factors of cationic guar gum were as follows: the vohn-ae of etberifying agent was 10 mL, reaction temperature and reaction time were 3-5 h and 60 ℃, respectively. The degree of substitution (DS) of CGG was 0.170 1, the luminousness was 97 %. The chemical structure of CGG was characterized by IR. The contrast among guar gum, hydroxypropyl guar gum and Cationic guar gum was analyzed by TG and DSC. Cationic groups

  4. Field assessment of guar gum stabilized microscale zerovalent iron particles for in-situ remediation of 1,1,1-trichloroethane

    Science.gov (United States)

    Velimirovic, Milica; Tosco, Tiziana; Uyttebroek, Maarten; Luna, Michela; Gastone, Francesca; De Boer, Cjestmir; Klaas, Norbert; Sapion, Hans; Eisenmann, Heinrich; Larsson, Per-Olof; Braun, Juergen; Sethi, Rajandrea; Bastiaens, Leen

    2014-08-01

    A pilot injection test with guar gum stabilized microscale zerovalent iron (mZVI) particles was performed at test site V (Belgium) where different chlorinated aliphatic hydrocarbons (CAHs) were present as pollutants in the subsurface. One hundred kilograms of 56 μm-diameter mZVI (~ 70 g L- 1) was suspended in 1.5 m3 of guar gum (~ 7 g L- 1) solution and injected into the test area. In order to deliver the guar gum stabilized mZVI slurry, one direct push bottom-up injection (Geoprobe) was performed with injections at 5 depths between 10.5 and 8.5 m bgs. The direct push technique was preferred above others (e.g. injection at low flow rate via screened wells) because of the limited hydraulic conductivity of the aquifer, and to the large size of the mZVI particles. A final heterogeneous distribution of the mZVI in the porous medium was observed explicable by preferential flow paths created during the high pressure injection. The maximum observed delivery distance was 2.5 m. A significant decrease in 1,1,1-TCA concentrations was observed in close vicinity of spots where the highest concentration of mZVI was observed. Carbon stable isotope analysis (CSIA) yielded information on the success of the abiotic degradation of 1,1,1-TCA and indicated a heterogeneous spatio-temporal pattern of degradation. Finally, the obtained results show that mZVI slurries stabilized by guar gum can be prepared at pilot scale and directly injected into low permeable aquifers, indicating a significant removal of 1,1,1-TCA.

  5. 魔芋胶与瓜胶未来产业竞争态势分析%Future Industrial Competition Analysis between Konjac Gum and Guar Gum

    Institute of Scientific and Technical Information of China (English)

    张东华; 汪庆平; 骆桂英

    2014-01-01

    The biological characteristics and the distribution areas of konjac and guar bean are compared. Judging from the comprehensive compression, breeding coefficient, biological yield, sale prices, and industrial application scale, even thorough guar gum is more common in the application for its large quantity and relatively low price, konjac gum be more competitive contrast to guar gum in the future with the increase of large scale of plantation and application of with new species, A.muelleri for the fundamental characters, viscosity and jellying function more superior.%比较魔芋和瓜尔豆生物学特性、现有资源区位优势及魔芋胶和瓜胶产品性状等,魔芋胶在理化指标方面明显优于瓜胶,尤其是粘度及凝胶特性显著好于瓜胶。弥勒魔芋规模种植必将伴随魔芋产量的大幅增加,可提升我国魔芋产业在全球的市场份额及产业集中度,显著增强魔芋胶的竞争力,逐渐动摇瓜胶在传统产业中的现有竞争优势。

  6. Strain and strain rate by two-dimensional speckle tracking echocardiography in a maned wolf Strain e strain rate por meio de ecocardiogratia speckle traking bidimensional em um lobo-guará

    Directory of Open Access Journals (Sweden)

    Matheus M. Mantovani

    2012-12-01

    ções miocárdicas. Objetivou-se avaliar a função miocárdica esquerda de um lobo guará por meio do uso da 2D STE. Desta forma, foram obtidas as variáveis Strain e Strain Rate longitudinais, circunferenciais e radiais, assim como a velocidade e o deslocamento longitudinais e radiais, utilizando os cortes eixo longo paraesternal direito quatro câmaras, paraesternal esquerdo apical quatro câmaras e eixo curto paraesternal direito no plano dos músculos papilares. Os resultados das variáveis longitudinais fora -13,52±7,88, -1,60±1,05, 4,34±2,52 e 3,86±3,04 para Strain (%, Strain rate (1/s, deslocamento (mm e velocidade (cm/s, respectivamente. Quanto ao Strain e Strain rate radiais e circunferenciais foram obtidos 24,39±14,23, 1,86±0,95 e -13,69±6,53, -1,01±0,48. Portanto, o presente estudo fornece os primeiros dados a respeito do uso desta ferramenta em lobos guarás, permitindo uma quantificação da função miocárdica de forma mais completa nesta espécie.

  7. Guar gum solutions for improved delivery of iron particles in porous media (Part 2): Iron transport tests and modeling in radial geometry

    Science.gov (United States)

    Tosco, Tiziana; Gastone, Francesca; Sethi, Rajandrea

    2014-10-01

    In the present work column transport tests were performed in order to study the mobility of guar-gum suspensions of microscale zero-valent iron particles (MZVI) in porous media. The results were analyzed with the purpose of implementing a radial model for the design of full scale interventions. The transport tests were performed using several concentrations of shear thinning guar gum solutions as stabilizer (1.5, 3 and 4 g/l) and applying different flow rates (Darcy velocity in the range 1 · 10- 4 to 2 · 10- 3 m/s), representative of different distances from the injection point in the radial domain. Empirical relationships, expressing the dependence of the deposition and release parameters on the flow velocity, were derived by inverse fitting of the column transport tests using a modified version of E-MNM1D (Tosco and Sethi, 2010) and the user interface MNMs (www.polito.it/groundwater/software). They were used to develop a comprehensive transport model of MZVI suspensions in radial coordinates, called E-MNM1R, which takes into account the non Newtonian (shear thinning) rheological properties of the dispersant fluid and the porous medium clogging associated with filtration and sedimentation in the porous medium of both MZVI and guar gum residual undissolved particles. The radial model was run in forward mode to simulate the injection of MZVI dispersed in guar gum in conditions similar to those applied in the column transport tests. In a second stage, we demonstrated how the model can be used as a valid tool for the design and the optimization of a full scale intervention. The simulation results indicated that several concurrent aspects are to be taken into account for the design of a successful delivery of MZVI/guar gum slurries via permeation injection, and a compromise is necessary between maximizing the radius of influence of the injection and minimizing the injection pressure, to guarantee a sufficiently homogeneous distribution of the particles around the

  8. 瓜尔豆胶降血脂作用研究进展%Advances in research of hypolipidemic efficacy of guar gum

    Institute of Scientific and Technical Information of China (English)

    梁菡峪; 王健; 丁晓雯; 张亚琼

    2013-01-01

    瓜尔豆胶是从印度豆类植物瓜尔豆中提取到的一种可溶性膳食纤维,自90年代引入中国以来,一直作为食品添加剂用于食品工业中.近年来,相关文献报道瓜尔豆胶对高血脂等疾病能起到很好的辅助调节作用.其具有的凝胶特性,能抑制在肠道内胆固醇的吸收,阻碍胆汁酸重吸收进入肝肠循环,导致胆汁酸和固醇排出;另一方面通过增强HMG-CoA还原酶的活性和降低葡萄糖吸收从而间接导致肝脏胆固醇合成减少.本文就瓜尔豆胶降血脂作用及其可能机制进行了综述,文章内容包括瓜尔豆胶的结构及化学组成、理化性质、功能应用和降血脂作用及机制四个部分,为瓜尔豆胶的科学利用提供参考.%Guar gum is a soluble dietary fiber which had been extracted from india bean guar.It had been used in food industry as food additives since been introduced into China in 1990s.ln recent years,it has been reported that guar gum could play a very good role of adjuvant regulation on hyperlipemia.lt can inhibit cholesterol absorption in the intestine,obstruction the absorption of bile acid into the enterohepatic circulation,leading to discharge of bile acids and sterols.On the other hand,guar gum can enhance the activity of HMG-CoA reeducate and decrease glucose uptake thus indirectly decrease the synthesis of hepatic cholesterol.In this paper,guar gum' s hypolipidemic effect and its possible mechanism to refer for scientific utilization of guar gum was reviewed.The content of the article include structure,physicochemical properties,function application,hypolipidemic effect and mechanism.

  9. 羟丙基瓜尔胶在离子液体中的制备%Preparation of hydroxypropyl guar gum in ionic liquid

    Institute of Scientific and Technical Information of China (English)

    战振生; 尹恒; 杜彬; 康如坤; 崔平

    2012-01-01

    In this paper,hydroxypropyl guar gum(HPG)was successfully prepared in an ionic liquid l-allyl-3-methylimidazolium chloride with sodium hydroxide as catalyst,and the molar substitution degree( MS) was determined by means of H NMR spectrosco-py. The effects of the dosage of the water,the dosage of the propylene oxide,reaction temperature and reaction time on MS of HPG were investigated. The HPG with the MS value of 0. 76 could be obtained under conditions of the mass ratio of water to guar gum 1. 7, that of NaOH to guar gum 5% ,that of propylene oxide to guar gum 3. 5 when the reaction was heated at 60 ℃ for 12h. In addition, the hydroxypropylation of the guar gum could be carried out without NaOH as catalyst using AmimCl as a reaction medium.%本文以离子液体1-烯丙基-3-甲基咪唑氯盐(AmimCl)为反应介质,以氢氧化钠为催化剂合成了羟丙基瓜尔胶(HPG),并通过1 H NMR确定了产品的摩尔取代度.探讨了水的用量、环氧丙烷的用量、反应温度和反应时间对摩尔取代度的影响.在水与瓜尔胶的质量比为1.7、氢氧化钠与瓜尔胶的质量比为5%、环氧丙烷与瓜尔胶的质量比为3.5、反应温度为60℃和反应时间为12h的条件下,摩尔取代度(MS)可以达到0.76.同时发现在不加催化剂NaOH的情况下,瓜尔胶在AmimCl中的羟丙基化反应同样可以发生,只是得到的HPG的MS相对较小.

  10. Study on preparation of cross-linked carboxymethyl guar gum%交联羧甲基瓜尔胶的制备

    Institute of Scientific and Technical Information of China (English)

    陈娜丽; 冯辉霞; 赵霞; 张娟

    2011-01-01

    以植物瓜尔胶为原料、环氧氯丙烷为交联剂、氨乙酸为羧甲基化试剂,制备了交联羧甲基瓜尔胶。研究了环氧氯丙烷的用量、氯乙酸的用量、氢氧化钠的用量及反应温度对产品取代度的影响;考查了产品糊的耐温性能,并用FT—IR对产品的结构进行了表征。实验结果表明:配料质量比瓜尔胶:环氧氯丙烷:氢氧化钠:氯乙酸为1.00:0.015:0.45:0.40,反应温度50℃时,产品的取代度达最高0.340。FT-IR分析结果表明,瓜尔胶分子中引入了羧甲基基团,交联羧甲基瓜尔胶成功制备。与原瓜尔胶糊相比,产品糊的耐温性能得到改善。%With natural guar gum as material,epichlorohydrin as cross-linking agent,chloroacetic acid as carboxymethylating agent,cross-linked carboxymethyl guar gum was prepared. The effects of epichlorohydrin dosage,chloroacetic acid dosage,sodium hydroxide dosage,and reaction temperature on the degree of substitution of product were studied. The temperature resistance of product paste was also investigated. The maximum degree of substitution of product of 0.340 was obtained under the following conditions: the mass ratio of guar gum :epichlorohydrin :sodium hydroxide :chloroacetic acid 1.00:0.015:0.45:0.40,reaction temperature 50℃. The FT-IR results showed that the group of carboxymethyl had introduced to the product,and crosslinked carboxymethyl guar gum was successfully prepared. Product paste had improved temperature resistance in contrast to native guar gum paste.

  11. Nanostructured SnO{sub 2} encapsulated guar-gum hybrid nanocomposites for electrocatalytic determination of hydrazine

    Energy Technology Data Exchange (ETDEWEB)

    Malik, Priya [Department of Applied Chemistry & Polymer Technology, Delhi Technological University, Shahbad Daulatpur, Main Bawana Road, Delhi 110042 (India); Srivastava, Manish [Department of Physics & Astrophysics, University of Delhi, Delhi 110007 (India); Verma, Ranjana [Solar Energy Material Laboratory, Department of Energy, Tezpur University, Tezpur, Assam 784 028 (India); Kumar, Manish [Department of Applied Chemistry & Polymer Technology, Delhi Technological University, Shahbad Daulatpur, Main Bawana Road, Delhi 110042 (India); Kumar, D., E-mail: dkumar@dce.ac.in [Department of Applied Chemistry & Polymer Technology, Delhi Technological University, Shahbad Daulatpur, Main Bawana Road, Delhi 110042 (India); Singh, Jay, E-mail: jay_singh143@yahoo.co.in [Department of Applied Chemistry & Polymer Technology, Delhi Technological University, Shahbad Daulatpur, Main Bawana Road, Delhi 110042 (India)

    2016-01-01

    The present article deals with synthesis of sol–gel derived tin dioxide (SnO{sub 2}) nanoparticles encapsulated in to guar gum (GG) biopolymer as the organic–inorganic hybrid materials for the determination of hydrazine. The organic–inorganic hybrid combines the perfunctory strength offered by the inorganic SnO{sub 2} nanoparticles with flexible binding sites provided by the organic biopolymer (GG) solution by the ultrasonication. The phase identification, crystalline size, surface morphology and optical properties of prepared SnO{sub 2} and SnO{sub 2}-GG nanocomposites has been investigated through FT-IR, XRD, SEM, AFM, TEM, UV–Vis, and PL techniques. The colloidal solution of SnO{sub 2} and GG is electrophoretically deposited (EPD) onto the indium tin-oxide (ITO) glass substrate and studied for the electrooxidation of hydrazine. Under the optimized experimental conditions, the linearity between the current response and the hydrazine concentration has been obtained in the range of 2–22 mM, with a low detection limit of 2.76 mM and a high sensitivity of 5.72 μA cm{sup −2}. Based on the linear increase in amperometric current, a sensitive hydrazine electrochemical sensor is constructed. The proposed SnO{sub 2}-GG/ITO electrode shows a good response time (35 s), reproducibility, and long-term stability. The obtained results suggest that SnO{sub 2}-GG nanocomposites electrode provides a favorable sensing platform for the electrochemical studies. In addition, the cyclic voltammetry (CV) studies are used to evaluate the kinetic parameters. - Graphical abstract: Synthesis of sol–gel derived tin dioxide (SnO{sub 2}) nanoparticles grafted in to gaur gum (GG) organic–inorganic hybrid nanocomposite for determination of hydrazine (HZ). Under optimized experimental conditions, SnO{sub 2}-GG/ITO electrode shows, linearity 2–22 mM, and detection limit 2.769 mM with high sensitivity of 5.72 μA cm{sup −2}. The results clearly suggest that SnO{sub 2}-GG

  12. 超级瓜尔胶理化特征及压裂液配方评价%PHYSICOCHEMICAL CHARACTERISTICS OF THE PROCESSED ENHANCED GUAR AND FORMULA EVALUATIONS FOR FRACTURING FLUID

    Institute of Scientific and Technical Information of China (English)

    王贤君; 韩松; 肖丹凤; 张明慧; 侯堡怀

    2011-01-01

    针对大庆油田特低渗透储层压裂增产改造的需要,开发了一种新型超级瓜尔胶压裂液.利用核磁共振和黏度实验技术表征了超级瓜尔胶的化学结构和相对分子质量,利用流变仪测定了超级瓜尔胶压裂液的流变性质.结果表明:超级瓜尔胶与瓜尔胶原粉的化学结构基本相同,但是相对分子质量却比瓜尔胶原粉高1.4倍左右;在相同温度和相同剪切速率条件下,配置相同剪切黏度压裂液所需超级瓜尔胶用量仅为羟丙基瓜尔胶用量的一半;和羟丙基瓜尔胶压裂液相比较,超级瓜尔胶配置的压裂液残渣含量降低了一半以上,破胶更加彻底.利用超级瓜尔胶压裂技术对海拉尔油田低渗透储层的61口井119个层位进行了压裂施工,平均产液强度为1.10 t/(m·d),比利用常规的羟丙基瓜尔胶压裂液技术对相同区块12口井22个层位进行压裂施工的平均产液强度提高了22.7%,取得了较好的增产效果.%Aiming at the demands of fracturing stimulation in ultra-low permeability reservoirs in Daqing Oilfield, a new kind of processed enhanced guar fracturing fluid is developed. The chemical structure and molecular weight of the processed enhanced guar are characterized through the application of nuclear magnetic resonance ( NMR) and viscosity measurement technique, and the rheological properties of the processed enhanced guar fracturing fluid is measured by rheometers. The result shows that: chemical structures of the processed enhanced guar and the guar powder are basically the same, but the molecular weight of the processed enhanced guar is approximately 1.4 times greater than that of guar gum powder. At the same temperature and the same shear rate, the usage of the processed enhanced guar used to prepare the fracturing fluid with the same shear viscosity is only half of the usage of hydroxypropyl guar. Compared with hydroxypropyl guar fracturing fluid, the residue content of the

  13. 烷基烯酮二聚体改性瓜尔胶的制备及应用%Preparation and Application of Alkyl Ketene Dimmer Modified Guar Gum

    Institute of Scientific and Technical Information of China (English)

    薛贝; 沈一丁; 杨晓武; 李培枝; 隋明炜

    2011-01-01

    The lactone group of A KI) and the activated hydroxyl of guar gum was esterifled and produce a new surface sizing agent with alkyl ketene dimmer ( AKD) 's hydrophobicity and guar gum's hydrophilicity. The guar gum modified by AKD was dissolved in ethanol without water. Paper surface sizing with the modified guar gum was carried out and die application result was measured. The effect of reaction temperature and reaction time in the modified guar gum preparation as well as the dosage of modified guar gum on sizing efficiency were discussed. The modified compound was characterized by the SEM, FT-IR. Stability experiment showed that when the ratio of the guar gum and AKD is 2-1, reaction temperature is 70℃ , reaction time is 4 h, the AKD can be grafted on the guar gum successfully. The sizing degree is 52 s when the dosage of the modified guar gum is 0.6%.%结合烷基烯酮二聚体(AKD)的疏水性与瓜尔胶的亲水性能,利用AKD的内酯基与瓜尔胶原粉上活性羟基发生酯化反应,得到了具有一定施胶度的新型表面施腔剂.将改性后的瓜尔胶配制成一定浓度的施胶液对纸张进行表面施胶,并测定了其施腔效果.讨论了瓜尔胶与AKD的反应温度、反应时间、改性瓜尔胶进行表面施胶时的用量等对施胶效果的影响.同时用扫描电镜(SEM)、红外光谱(FT-IR)和接触角仪(CA)等测量手段对其结构、性能和应用效果进行了表征.结果表明,当瓜尔胶原粉与AKD质量比为2∶1,反应温度为70℃,反应时间4h时,在瓜尔胶分子上成功接枝了烃基长链,改性瓜尔胶表面施胶用量为0.6%时,纸张的施胶度可以达到52 s.

  14. Synthesis and characterization of PEPO grafted carboxymethyl guar and carboxymethyl tamarind as new thermo-associating polymers.

    Science.gov (United States)

    Gupta, Nivika R; Torris A T, Arun; Wadgaonkar, Prakash P; Rajamohanan, P R; Ducouret, Guylaine; Hourdet, Dominique; Creton, Costantino; Badiger, Manohar V

    2015-03-06

    New thermo associating polymers were designed and synthesized by grafting amino terminated poly(ethylene oxide-co-propylene oxide) (PEPO) onto carboxymethyl guar (CMG) and carboxymethyl tamarind (CMT). The grafting was performed by coupling reaction between NH2 groups of PEPO and COOH groups of CMG and CMT using water-soluble EDC/NHS as coupling agents. The grafting efficiency and the temperature of thermo-association, T(assoc) in the copolymer were studied by NMR spectroscopy. The graft copolymers, CMG-g-PEPO and CMT-g-PEPO exhibited interesting thermo-associating behavior which was evidenced by the detailed rheological and fluorescence measurements. The visco-elastic properties (storage modulus, G'; loss modulus, G") of the copolymer solutions were investigated using oscillatory shear experiments. The influence of salt and surfactant on the T(assoc) was also studied by rheology, where the phenomenon of "Salting out" and "Salting in" was observed for salt and surfactant, respectively, which can give an easy access to tunable properties of these copolymers. These thermo-associating polymers with biodegradable nature of CMG and CMT can have potential applications as smart injectables in controlled release technology and as thickeners in cosmetics and pharmaceutical formulations.

  15. Silver nanoparticles-containing dual-function hydrogels based on a guar gum-sodium borohydride system

    Science.gov (United States)

    Dai, Lei; Nadeau, Ben; An, Xingye; Cheng, Dong; Long, Zhu; Ni, Yonghao

    2016-01-01

    Dual-function hydrogels, possessing both stimuli-responsive and self-healing properties, have recently attracted attention of both chemists and materials scientists. Here we report a new paradigm using natural polymer (guar gum, GG) and sodium borohydride (NaBH4), for the preparation of silver nanoparticles (AgNPs)-containing smart hydrogels in a simple, fast and economical way. NaBH4 performs as a reducing agent for AgNPs synthesis using silver nitrate (AgNO3) as the precursor. Meanwhile, sodium metaborate (NaBO2) (from NaBH4) behaves as a cross-linking agent between GG molecular chains. The AgNPs/GG hydrogels with excellent viscoelastic properties can be obtained within 3 min at room temperature without the addition of other cross-linkers. The resultant AgNPs/GG hydrogels are flowable and injectable, and they possess excellent pH/thermal responsive properties. Additionally, they exhibit rapid self-healing capacity. This work introduces a facile and scale-up way to prepare a class of hydrogels that can have great potential to biomedical and other industrial applications. PMID:27819289

  16. FORMULATION AND IN VITRO EVALUATION OF GLIPIZIDE AS FLOATING DRUG DELIVERY SYSTEM WITH NATURAL POLYMER (GUAR-GUM

    Directory of Open Access Journals (Sweden)

    Singh Amit Kumar

    2012-08-01

    Full Text Available The purpose of this investigation was to prepare a gastro retentive drug delivery system of Glipizide. Floating tablets of Glipizide were prepared employing different polymers like HPMC K15M, Guar-Gum, Carbopol 934p and Magnesium Stearate by effervescent technique. Sodium bicarbonate and citric acid were incorporated as a gas generating agent. The Floating tablets were evaluated for uniformity of weight, hardness, friability, drug content, in- vitro buoyancy, swelling study, dissolution studies and stability studies. The drug release profile and floating properties was investigated. The prepared tablets exhibited satisfactory physico-chemical characteristics. All the prepared batches showed good in vitro buoyancy. It was aimed to prepare for prolonged residence in the stomach over conventional Gastroretentive approaches. The tablets are produced by direct compression method. The release of the drug is concern from the nine formulations. F5 is a best formulation to determine the mode of release the data was subjected to Zero Order model. F5 optimized formulation released approximately 98.15% drug in 12 hours in vitro.

  17. Rheological and Pasting Properties of Naked Barley Flour as Modified by Guar, Xanthan, and Locust Bean Gums

    Science.gov (United States)

    Yoon, Sung-Jin; Lee, Youngseung; Yoo, Byoungseung

    2016-01-01

    To understand the effects of adding different gums (guar, xanthan, and locust bean gums) on naked barley flour (NBF), the rheological and pasting properties of NBF-gum mixtures were measured at different gum concentrations (0, 0.3, and 0.6% w/w). Steady shear rheological properties were determined by rheological parameters for power law and Casson models. All samples showed a clear trend of shear-thinning behavior (n=0.16~0.48) and had a non-Newtonian nature with yield stress. Consistency index, apparent viscosity, and yield stress values increased with an increase in gum concentration. Storage modulus values were more predominant than loss modulus values with all concentrations of gums. There is a more pronounced synergistic effect of elastic properties of NBF in the presence of xanthan gum. Rapid visco analyser pasting properties showed that the addition of gums resulted in a significant increase in the peak, breakdown, setback, and final viscosities, whereas the pasting temperature decreased. PMID:28078260

  18. Selective removal of toxic anionic dyes using a novel nanocomposite derived from cationically modified guar gum and silica nanoparticles.

    Science.gov (United States)

    Patra, Abhay Shankar; Ghorai, Soumitra; Ghosh, Shankhamala; Mandal, Barun; Pal, Sagar

    2016-01-15

    A novel nanocomposite derived from cationically modified guar gum and in-situ incorporated SiO2 NP (cat-GG/SiO2) has been developed. The cat-GG has been synthesised by grafting poly(2-(diethylamino)ethyl methacrylate) on GG backbone. Various analyses endorse the suitability of cat-GG as well-organized template for the development of homogeneous SiO2 NPs. Dye adsorption studies predict that cat-GG/SiO2 efficiently and selectively adsorb anionic dyes (reactive blue-RB and Congo red-CR) from mixture of dye solutions. This is because of high surface area, multifunctional chelating H-bonding interactions and electrostatic interactions of cationic adsorbent with anionic dyes. Dyes adsorbed on the composite surface are desorbed reversibly using pH 10 stripping solution. Besides, cat-GG/SiO2 has been recycled efficiently with no prominent loss of dye uptake capacity, even after 4 adsorption-desorption cycles.

  19. Industrial Application of Guar Gum Retention Aid in Making Cigarette Paper%瓜尔胶助留剂在卷烟纸企业的工业应用

    Institute of Scientific and Technical Information of China (English)

    罗彤彤

    2011-01-01

    该文探讨了瓜尔胶助留剂在卷烟纸企业的工业应用,研究了其细度、水不溶物、pH和黏度等技术指标对卷烟纸质量的影响,尤其是最为关键的黏度指标。%Industrial application of guar gum retention aid in making cigarette paper is discussed in this paper.Technical specifications on the guar gum,including its fineness,contents of water insoluble substances,pH and especially the solution viscosity,are studies in detail,focusing on how they influence the quality of cigarette paper after the application of guar gum.

  20. 醇对瓜尔胶高分子水溶液黏度的影响%Effect of Alcohol upon the Viscosity of Polymer Guar Gum in Aqueous Solution

    Institute of Scientific and Technical Information of China (English)

    张玲; 杨海洋; 李化真; 朱平平; 何平笙

    2011-01-01

    Effect of both isopropyl alcohol and ethylene glycol upon the viscosity of polymer guar gum in aqueous solution was measured. It has been found that with the addition of isopropyl alcohol into guar gum solution, the intrinsic viscosity of solution decreases gradually whereas the Huggins parameter κH increases successively. On the other hand, by adding ethylene glycol into guar gum solution, the intrinsic viscosity of solution increases gradually whereas the Huggins parameter κH decreases successively. Our experimental results indicate that both isopropyl alcohol and ethylene glycol associate greatly with guar gum in solution. However, the effect of either isopropyl alcohol or ethylene glycol upon the hydrophobic property and steric hindrance of guar gum is different. As a result, the effect of either isopropyl alcohol or ethylene glycol upon the viscosity behavior of guar gum is different.%潮定了异丙醇和乙二醇对瓜尔胶高分子水溶液黏度的影响,发现随着异丙醇的加入,瓜尔胶高分子水溶液的特性黏数逐渐减小,Huggins相互作用参数会逐渐增加;与此相反,随着乙二醇的加入,瓜尔胶高分子水溶液的特性黏数逐渐增加,Huggins相互作用参数却逐渐减小.醇和瓜尔胶高分子之间缔合导致高分子链疏水性质和空间位阻效应的改变,是异丙醇和乙二醇对瓜尔胶高分子水溶液黏度行为影响显著不同的根本原因.

  1. 疏水改性胍胶稠化剂的制备及结构与性能的相关性%Synthesis of Hydrophobic Modified Guar Gum Thickener and Correlation Analysis of Its Structure and Property

    Institute of Scientific and Technical Information of China (English)

    赵建波; 沈一丁; 王磊; 赖小娟

    2011-01-01

    The modified guar gum was synthesized with guar gum as material and bromododecane as etherifying agent by suspension polymerization method.The solution and gel of the modified guar gum were also prepared.The structure and the property of the modified guar gum were analysized by Fourier transform infrared spectrum(FT-IR),X-ray diffraction(XRD) and thermogravimetric analysis(TGA).The heat resistance and the viscoelasticity modulus of the gel were also researched by rheometer.The results of FT-IR and XRD show that the hydrophobic long chain has been introduced into the guar gum successfully.TGA indicates that the modified guar gum has higher thermal stability.The rheology tests reflect that with different temperature conditions,the shear viscosity,the viscoelasticity modulus of the gel and the heat resistance of the modified guar gum are both better than that of the unmodified.The modified guar gum can be used as thickener of fracturing fluid,and it can reduce its amount.%以胍胶为原料,溴代十二烷(C12H25Br)为醚化剂,在碱的催化作用下通过悬浮聚合制备出疏水改性胍胶,并制备了改性胍胶的水溶液及冻胶。通过红外、X射线衍射(XRD)、热重(TGA)测试对改性胍胶结构与性能进行了研究。测定了溶液表观黏度,并对冻胶耐剪切、耐温性能及粘弹性进行了研究。红外和XRD分析表明,疏水长链被成功引入胍胶,TGA分析表明,疏水改性可以提高胍胶的热稳定性。相同浓度的改性胍胶溶液的稳定性及黏度较胍胶溶液的高。测试表明,溶液在不同温度下的剪切黏度及冻胶的粘弹性模量、耐温能力等改性胍胶均优于胍胶。改性胍胶作为压裂液的稠化剂可以降低其使用浓度。

  2. The Evaluation and Application of a Instant Guar Gum%一种速溶胍胶的评价与应用

    Institute of Scientific and Technical Information of China (English)

    闫鹏; 汪志臣; 袁丹丹; 何明亮

    2014-01-01

    Multistage fracturing of horizontal well is a good explored mode for unconventional oil and gas resources.In this mode,continuous mix is required,and fracturing liquid is required to dissolve and disperse in a short time in order to fit application demand.The basic physical property,dispersibility and swelling property of an instant guar gum are studied,which is compared with another used guar gum in work site.The results showed that the instant guar gum was characteristic of favorable dispersibility and swellability and met the requirements of operation.It has been used in Xinjiang oil field successfully.%水平井多级压裂是对非常规油气藏资源的一种良好的开发模式。这种开发模式需要的压裂现场工艺是连续混配,要求压裂液体能够在短时间分散溶解好,原液黏度要在短时间达到施工要求。经过实验室评价,对一种速溶胍胶的基本物性、分散性能以及溶胀性能进行了评价,并与现场常规使用的一级胍胶的性质进行对比。实验表明,这种速溶胍胶在分散性和溶胀性上具有良好的性能,能够满足现场施工要求。新疆油田成功应用该速溶胍胶进行施工。

  3. Optimization of guar gum extraction by response surface methodology%响应面法优化瓜儿豆胶提取工艺

    Institute of Scientific and Technical Information of China (English)

    黄杰; 黄健峰; 陈珊虹; 于新; 黄士玮; 桑圣贤

    2014-01-01

    以瓜儿豆( Cyamopsis tetragonoloba ( Linn.) Taub.)种子为原料,在单因素试验的基础上,选定料液比、浸提温度和pH进行中心组合试验,利用响应面法优化瓜儿豆胶的提取工艺.结果表明,瓜儿豆胶的优化提取工艺条件为: pH 4.0,52℃,料液比1∶30 g/mL,验证试验表明,瓜儿豆胶的提取率实际值为30.3%,与预测值(30.6%)接近.%Response surface analysis was applied to optimize the extraction techniques of guar gum from the seed of Cyamopsis tetragonoloba ( Linn.) Taub.based on the results of single factor test with tem-perature , pH value and ratio of material to water as the factors .The results showed that the optimal con-ditions of guar gum extraction were:pH 4.0, 52℃and the ratio of solid to liquid 1∶30 g/mL, the actual extraction rate of guar gum reached up to 30.3%, which was close to the predicted value of 30.6%.

  4. Study on preparation and properties of modified guar-based fracturing fluids%改性瓜胶压裂液的制备及性能研究

    Institute of Scientific and Technical Information of China (English)

    吴亚; 赵攀; 李凡; 徐甜莉; 白海涛; 吴新民

    2015-01-01

    分别以十二烷基和磺酸盐甜菜碱为修饰基团,以瓜胶原粉为主剂,制备了2种改性瓜胶增稠剂:疏水改性羟丙基瓜胶和磺酸盐甜菜碱型瓜胶。模拟现场配方,对其配制的压裂液的抗剪切性能和耐温性能进行评价。通过对比发现磺酸盐甜菜碱型胍胶比油田提供CJ2-6胍胶耐温抗剪切能力有所下降,疏水改性羟丙基胍胶比油田提供CJ2-6胍胶耐温抗剪切能力有明显改善。其中,疏水改性羟丙基瓜胶80℃下剪切60 min 后,表观粘度为93.4 mPa· s,比油田提供CJ2-6瓜胶耐温抗剪切能力有明显改善。可以考虑疏水改性羟丙基瓜胶在压裂液体系的进一步应用。%Two modified guar-based fluids were prepared using meloncollagen powder as the main agent , halogenated dodecylane and sulfonate betaine as modified groups ,respectively.According to oil field,the shear ability and temperature resistance were evaluated .It was found sulfonate betaine-type guanidine gum are less tolerant of high-shear conditions and high temperature than CJ 2-6 guanidine gum ,while the hy-drophobic modification of hydroxypropyl guar gum are less tolerant of high-shear conditions and high tem-perature.Among them,the apparent viscosity of the hydrophobically modified hydroxypropyl guar gum re-mains 93.4 mPa· s for shearing 60 min at 80℃.Considering the hydrophobically modified hydroxypropyl guar gum in the further application of fracturing fluid system .

  5. Prebiotic Effects and Fermentation Kinetics of Wheat Dextrin and Partially Hydrolyzed Guar Gum in an In Vitro Batch Fermentation System

    Directory of Open Access Journals (Sweden)

    Justin Carlson

    2015-08-01

    Full Text Available Scientific research demonstrates that two indigenous gut bacteria, Lactobacillus and Bifidobacterium can contribute to human health. Although these bacteria can be consumed as probiotics, they can also be produced in the gut by bacteria, and are then called prebiotics. The primary objective of this in vitro study was to quantitatively analyze at the genus level how two dietary fibers, wheat dextrin (WD and partially hydrolyzed guar gum (PHGG changed the levels of these two gut bacteria at 12 and 24 h, via real time qualitative polymerase chain reaction (qPCR. Secondary objectives were changes in fecal pH, short chain fatty acids (SCFAs and total gas volume produced. At 12 h WD was more bifidogenic (9.50 CFU log10/mL than PHGG (9.30 CFU log10/mL (p = 0.052, and also at 24 h WD (9.41 CFU log10/mL compared with PHGG (9.27 CFU log10/mL (p = 0.043. WD produced less total SCFAs at both 12 and 24 h than PHGG, and produced significantly lower amounts of gas at 12 and 24 h (p < 0.001. Both PHGG and WD also promoted growth of Lactobacilli when measured at 12 and 24 h compared with the 0 h analysis, indicating that both fibers are lactogenic. These results demonstrate the prebiotic effect of WD and PHGG. Based on fermentation kinetics, PHGG is more rapidly fermented than WD, and both fibers show prebiotic effects as early as 12 h.

  6. Prebiotic Effects and Fermentation Kinetics of Wheat Dextrin and Partially Hydrolyzed Guar Gum in an In Vitro Batch Fermentation System

    Science.gov (United States)

    Carlson, Justin; Hospattankar, Ashok; Deng, Ping; Swanson, Kelly; Slavin, Joanne

    2015-01-01

    Scientific research demonstrates that two indigenous gut bacteria, Lactobacillus and Bifidobacterium can contribute to human health. Although these bacteria can be consumed as probiotics, they can also be produced in the gut by bacteria, and are then called prebiotics. The primary objective of this in vitro study was to quantitatively analyze at the genus level how two dietary fibers, wheat dextrin (WD) and partially hydrolyzed guar gum (PHGG) changed the levels of these two gut bacteria at 12 and 24 h, via real time qualitative polymerase chain reaction (qPCR). Secondary objectives were changes in fecal pH, short chain fatty acids (SCFAs) and total gas volume produced. At 12 h WD was more bifidogenic (9.50 CFU log10/mL) than PHGG (9.30 CFU log10/mL) (p = 0.052), and also at 24 h WD (9.41 CFU log10/mL) compared with PHGG (9.27 CFU log10/mL) (p = 0.043). WD produced less total SCFAs at both 12 and 24 h than PHGG, and produced significantly lower amounts of gas at 12 and 24 h (p < 0.001). Both PHGG and WD also promoted growth of Lactobacilli when measured at 12 and 24 h compared with the 0 h analysis, indicating that both fibers are lactogenic. These results demonstrate the prebiotic effect of WD and PHGG. Based on fermentation kinetics, PHGG is more rapidly fermented than WD, and both fibers show prebiotic effects as early as 12 h.

  7. Viscoelastic gels of guar and xanthan gum mixtures provide long-term stabilization of iron micro- and nanoparticles

    Science.gov (United States)

    Xue, Dingqi; Sethi, Rajandrea

    2012-11-01

    Iron micro- and nanoparticles used for groundwater remediation and medical applications are prone to fast aggregation and sedimentation. Diluted single biopolymer water solutions of guar gum (GG) or xanthan gum (XG) can stabilize these particles for few hours providing steric repulsion and by increasing the viscosity of the suspension. The goal of the study is to demonstrate that amending GG solutions with small amounts of XG (XG/GG weight ratio 1:19; 3 g/L of total biopolymer concentration) can significantly improve the capability of the biopolymer to stabilize highly concentrated iron micro- and nanoparticle suspensions. The synergistic effect between GG and XG generates a viscoelastic gel that can maintain 20 g/L iron particles suspended for over 24 h. This is attributed to (i) an increase in the static viscosity, (ii) a combined polymer structure the yield stress of which contrasts the downward stress exerted by the iron particles, and (iii) the adsorption of the polymers to the iron surface having an anchoring effect on the particles. The XG/GG viscoelastic gel is characterized by a marked shear thinning behavior. This property, coupled with the low biopolymer concentration, determines small viscosity values at high shear rates, facilitating the injection in porous media. Furthermore, the thermosensitivity of the soft elastic polymeric network promotes higher stability and longer storage times at low temperatures and rapid decrease of viscosity at higher temperatures. This feature can be exploited in order to improve the flowability and the delivery of the suspensions to the target as well as to effectively tune and control the release of the iron particles.

  8. Guar gum succinate-sodium alginate beads as a pH-sensitive carrier for colon-specific drug delivery.

    Science.gov (United States)

    Seeli, D Sathya; Dhivya, S; Selvamurugan, N; Prabaharan, M

    2016-10-01

    Guar gum succinate - sodium alginate (GGS-SA) beads cross-linked with barium ions were prepared and characterized as a pH sensitive carrier for colon-specific drug delivery. The structure of GGS-SA beads was confirmed by FT-IR spectroscopy. Scanning Electron Microscope (SEM) studies revealed that the drug loaded GGS-SA beads prepared using 2:2 (w/v) weight percent of GGS and SA had a diameter about 1.4mm and roughly spherical in shape. X-ray diffraction (XRD) studies showed that the peaks corresponding to GGS and SA at 13.5°, 17.5°, 20.2° and 13.5°, 22°, 24.1°, respectively were destroyed in GGS-SA beads which show that these beads are more amorphous in nature. Swelling studies demonstrated the pH-dependent swelling behavior of GGS-SA beads. The beads showed higher swelling degrees in pH 7.4 than that in pH 1.2 due to the existence of anionic groups in the polymer chains. The drug release study showed that the amount of model drug, ibuprofen, released from the GGS-SA beads was higher in pH 7.4 than that in pH 1.2 due to the pH-dependent swelling behavior of the beads. MTT assay revealed that GGS-SA beads at a concentration range of 0-30μg/ml had no cytotoxic effect on the cultured mouse mesenchymal stem cells (C3H10T1/2). These results suggest that GGS-SA beads can be used as effective colon-specific drug delivery system with pH-dependent drug release ability. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Removal of Chromium(VI from aqueous solution using guar gum–nano zinc oxide biocomposite adsorbent

    Directory of Open Access Journals (Sweden)

    Tabrez A. Khan

    2017-05-01

    Full Text Available Guar gum–nano zinc oxide (GG/nZnO biocomposite was used as an adsorbent for enhanced removal of Cr(VI from aqueous solution. The maximum adsorption was achieved at 50 min contact time, 25 mg/L Cr(VI conc., 1.0 g/L adsorbent dose and 7.0 pH. Langmuir, Freundlich, Dubinin–Kaganer–Radushkevich and Temkin isotherm models were used to interpret the experimental data. The data obeyed both Langmuir and Freundlich models (R2 = 0.99 indicating a multilayer adsorption of Cr(VI onto the heterogeneous surface. The linear plots of Temkin isotherm showed adsorbent-adsorbate interactions. Moreover, the energy obtained from DKR isotherm (1.58–2.24 kJ/mol indicated a physical adsorption of the metal ions onto the adsorbent surface, which implies more feasibility of the regeneration of the adsorbent. GG/nZnO biocomposite adsorbent showed an improved adsorption capacity for Cr(VI (qm = 55.56 mg/g as compared to other adsorbents reported in the literature. Adsorption process followed pseudo-second order kinetics; controlled by both liquid-film and intra-particle diffusion mechanisms. Thermodynamic parameters (ΔGo, ΔHo and ΔSo reflected the feasibility, spontaneity and exothermic nature of adsorption. The results suggested that GG/nZnO biocomposite is economical, eco-friendly and capable to remove Cr(VI from natural water resources.

  10. Viscoelastic gels of guar and xanthan gum mixtures provide long-term stabilization of iron micro- and nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Xue Dingqi [Politecnico di Torino, Dipartimento Scienza Applicata e Tecnologia-DISAT and Dipartimento di Ingegneria dell' Ambiente, del Territorio e delle Infrastrutture-DIATI (Italy); Sethi, Rajandrea, E-mail: rajandrea.sethi@polito.it [Politecnico di Torino, Dipartimento di Ingegneria dell' Ambiente, del Territorio e delle Infrastrutture-DIATI (Italy)

    2012-11-15

    Iron micro- and nanoparticles used for groundwater remediation and medical applications are prone to fast aggregation and sedimentation. Diluted single biopolymer water solutions of guar gum (GG) or xanthan gum (XG) can stabilize these particles for few hours providing steric repulsion and by increasing the viscosity of the suspension. The goal of the study is to demonstrate that amending GG solutions with small amounts of XG (XG/GG weight ratio 1:19; 3 g/L of total biopolymer concentration) can significantly improve the capability of the biopolymer to stabilize highly concentrated iron micro- and nanoparticle suspensions. The synergistic effect between GG and XG generates a viscoelastic gel that can maintain 20 g/L iron particles suspended for over 24 h. This is attributed to (i) an increase in the static viscosity, (ii) a combined polymer structure the yield stress of which contrasts the downward stress exerted by the iron particles, and (iii) the adsorption of the polymers to the iron surface having an anchoring effect on the particles. The XG/GG viscoelastic gel is characterized by a marked shear thinning behavior. This property, coupled with the low biopolymer concentration, determines small viscosity values at high shear rates, facilitating the injection in porous media. Furthermore, the thermosensitivity of the soft elastic polymeric network promotes higher stability and longer storage times at low temperatures and rapid decrease of viscosity at higher temperatures. This feature can be exploited in order to improve the flowability and the delivery of the suspensions to the target as well as to effectively tune and control the release of the iron particles.

  11. Estudio de la fotodegradación de ácido fólico encapsulado en microesferas de goma arábiga y maltodextrina Study of photodegradation of folic acid encapsulated in microspheres of gum arabic and maltdextrin

    Directory of Open Access Journals (Sweden)

    Seneida Lopera Cardona

    2010-12-01

    Full Text Available En este estudio se adaptó un método HPLC de par iónico que permitió medir de forma selectiva el ácido fólico y sus 2 productos de degradación formados en las condiciones de irradiación usadas (lámpara de xenón a 250 Wm-2. Los tiempos de retención fueron: ácido fólico 10,2 min, formilpterina 4,4 min y p-aminobenzoil-L-ácido glutámico 6,1 min. El método se aplicó para determinar la longitud de onda responsable de la fotodegradación y para cuantificar el porcentaje de degradación que sufre el ácido fólico incorporado en microesferas obtenidas por secado por aspersión y con proporciones diferentes de goma arábiga-maltodextrina: 100-0, 80-20, 70-30 y 50-50, como materiales de cubierta. Se encontró como responsable de la fotodegradación la radiación de 350 nm, y las microesferas con mayor contenido de goma arábiga fueron las que presentaron mayor capacidad de proteger el ácido fólico, en estas el porcentaje de degradación fue de 20,1 % mientras que en el control fue de 49,2 %.In present paper a par ionic HPLC method was adapted to measure in a selective way the folic acid and its two degradation products formed under the irradiation conditions used (250 Wm². The retention times were: folic acid (10.2 min; formylpterin (4,4 min and p-aminobenzoil-glutamic acid (6,1 min. Method was applied to determine the wavelength accounting for photodegradation and also to quantify the degradation percentage suffering ty the folic acid added in microspheres obtained by aspersion driying and with different ratios of gum arabic and maltodextrin: 100-0, 80-20, 70-30 and 50-50 as covering materials. The responsible of photodegradation was the 350 nm radiacion and the microspheres with a great content of gum arabic had the greater ability to protect the folic acid, in these ones el degradation percentage was of 20.1 % whereas in the control it was of 49.2 %.

  12. The Guará Campaign: A series of rocket-radar investigations of the Earth's upper atmosphere at the magnetic equator

    Science.gov (United States)

    Pfaff, R. F.; Sobral, J. H. A.; Abdu, M. A.; Swartz, W. E.; LaBelle, J. W.; Larsen, M. F.; Goldberg, R. A.; Schmidlin, F. J.

    The Guará Campaign consisted of a series of sounding rockets that were launched from August-October, 1994 at a new launch facility at Alcântara, Brazil, which is within one degree of the Earth's magnetic equator. The campaign consisted of focused scientific experiments designed to investigate the electrodynamics and irregularities in the equatorial ionosphere and mesosphere and to study their relationship with neutral upper atmosphere motions. In all, 13 large sounding rockets and 20 small meteorological rockets were launched as part of four different experiment groups designed to investigate: (1) the daytime equatorial electrojet, (2) very high altitude Spread-F processes, (3) sunset electrodynamics, and (4) middle atmosphere-thermosphere coupling at the equator. All of the experiments utilized ground-based scientific instruments including a VHF backscatter radar interferometer, magnetometers, ionosondes, and scintillation receivers. The project was a joint undertaking of the National Aeronautics and Space Administration (NASA) of the United States and the Instituto Nacional de Pesquisas Espacias (INPE) of Brazil. The project was named the Guará Campaign after a beautiful species of bird that is native to the equatorial region of Brazil.

  13. The influence of carboxymethylcellulose, xanthan and guar-gum addition in bread dough before freezing on metabolism and viability of Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Kocić-Tanackov Sunčica D.

    2009-01-01

    Full Text Available Doughs were prepared with different concentrations of carboxymethylcellulose, xanthan, and guar-gum (0.1, 0.2 and 0.3% in doughs, freezed at -20°C and analyzed after 0, 7, 15 and 30 days. Pure Saccharomyces cerevisiae culture was isolated from dough and was cultivated under optimal conditions during 24 hrs to determine the following parameters: specific growth rate, fermentative activities and cytochromes contents in intact cells with the aim of determining the respiration intensity. During freezing of dough for 30 days, the percentage of living cells from dough surface was 53.11% and from the middle 54.95%. Carboxymethylcellulose in concentration of 0.3 and 0.5% increased number of survived cells on the surface to 70.64, and 70.28% and in the middle to 74.79, and 76.54%, respectively. Guar-gum increased number of survived cells only in concentration of 0.1% on the surface to 70.17% and in the middle of the dough to 75.26%. The mean specific growth rate decreased by approximately 10% during 30 days of storage at -20°C. Content of cytochromes in intact cells decreased in all samples during freezing.

  14. Efficient and rapid adsorption characteristics of templating modified guar gum and silica nanocomposite toward removal of toxic reactive blue and Congo red dyes.

    Science.gov (United States)

    Pal, Sagar; Patra, Abhay Shankar; Ghorai, Soumitra; Sarkar, Amit Kumar; Mahato, Vivekananda; Sarkar, Supriyo; Singh, R P

    2015-09-01

    The present study highlights the potentiality of sol-gel synthesized guar gum-graft-poly (acrylamide)/silica (g-GG/SiO2) hybrid nanocomposite toward the rapid removal of toxic reactive blue 4 (RB) and Congo red (CR) dyes from aqueous solution. Various physicochemical characterizations support the feasibility of the functionalized guar gum matrix as efficient template for the formation of homogeneous nanoscale silica particles. The composite demonstrates rapid and superior adsorption efficiency of RB (Qmax: 579.01 mg g(-1) within 40 min) and CR (Qmax: 233.24 mg g(-1) within 30 min) dyes from aqueous environment. Here, the pH driven adsorption process depends strongly on the ionic strength of the salt solution. The adsorption kinetics data predicts that pseudo second-order (surface adsorption) and intraparticle diffusion take place simultaneously. The adsorption equilibrium is in good agreement with the Langmuir isotherm, while the thermodynamics study confirms spontaneous nature of the adsorption process. Desorption study predicts the excellent regenerative efficacy of nanocomposite.

  15. Preparation of guar gum scaffold film grafted with ethylenediamine and fish scale collagen, cross-linked with ceftazidime for wound healing application.

    Science.gov (United States)

    Jana, Piyali; Mitra, Tapas; Selvaraj, Thirupathi Kumara Raja; Gnanamani, A; Kundu, P P

    2016-11-20

    Present study describes the synthesis of carboxymethyl guar gum (CMGG) from the native guar gum (GG) and the prepared CMGG is grafted with ethylenediamine (EDA) to form aminated CMGG. Then, fish scale collagen and aminated CMGG are cross-linked by ceftazidime drug through non- covalent ionic interaction. The resultant cross-linked film is subjected to the analysis of (1)HNMR, ATR-FTIR, TGA, SEM and XRD. The TNBS results revealed that 45% of interaction between EDA and CMGG and 90-95% of Ceftazidime is released from aminated CMGG-Ceftazidime-Collagen (ACCC) film after 96h of incubation at physiological pH. In vitro cell line studies reveal the biocompatibility of the cross-linked film and the antimicrobial studies display the growth inhibition against Staphylococcus aureus and Pseudomonas aeruginosa organisms. Overall, the study indicates that the incorporation of Ceftazidime into collagen and aminated CMGG can improve the functional property of aminated CMGG as well as collagen, leading to its biomedical applications.

  16. Identification of two additives, locust bean gum (E-410) and guar gum (E-412), in food products by DNA-based methods.

    Science.gov (United States)

    Urdiain, M; Doménech-Sánchez, A; Albertí, S; Benedí, V J; Rosselló, J A

    2004-07-01

    Locust bean gum (E-410) and guar gum (E-412) are high molecular weight galactomannans used by the food industry as versatile food additives. The compounds, although chemically closely related, do not have the same functional properties when used in foods, and the substitution or unadvertised addition of either could change the desired qualities of the product. Analytical discrimination between E-410 and E-412 is technically difficult since they only differ in their galactose: mannose ratios, being 1 : 4 and 1 : 2 for locust bean gum and guar gum, respectively. A qualitative DNA-based method is reported for the authentication of additives E-410 and E-412 in finished food products (ice cream, dehydrated desserts, milk derivatives, dehydrated soups, salad dressing, marmalade and meat) from small quantities of food. DNA sequences from the nuclear ribosomal spacers of Ceratonia siliqua and Cyamopsis tetragonoloba, the plant sources of E-410 and E-412, respectively, were used to design polymerase chain reaction primers specific for each additive (PA23/PA21 and PG22/PG21). Twenty-two foods were analysed for the presence of E-410 and E-412 additives by this single-step polymerase chain reaction-based method. Positive DNA amplifications with the E-410 and/or E-412 primers were obtained in all 19 samples reported to contain either additive.

  17. The effects of glycerol and guar-xanthan mixture on mechanical and barrier properties of starch based edible films - chemometric analysis

    Directory of Open Access Journals (Sweden)

    Šuput Danijela Z.

    2016-01-01

    Full Text Available The aim of this work was to evaluate the simultaneous effect of glycerol (30%, 40%, 50% and guar-xanthan gum addition (0.1%, 0.3%, 0.5% effect on starch based edible film mechanical and barrier properties. According to Response Surface Methodology, the most influential parameter in the second order polynomial models calculation was the percentage of glycerol, while the linear term of guar-xanthan content was important only for second order polynomial model calculation for tensile strength and water vapor permeability. According to Principal Component Analysis, samples grouping along the first component are primarily due to the content of glycerol, which is also confirmed by ANOVA analysis. According Cluster Analysis, two separate clusters are observed on the dendrogram, which includes the right (with the increased value of tensile strength and the left cluster (with the increased value of elongation break and water vapor permeability. The observed distance the two clusters is considerable (approx. 80. [Projekat Ministarstva nauke Republike Srbije, br. TR-31055: Osmotic dehydration of food - energy and environmental aspects of sustainable production

  18. 羟丙基胍胶压裂液交联增效剂研究%Study on crosslinking boosters of fracturing with hydroxypropyl guar gum

    Institute of Scientific and Technical Information of China (English)

    马俯波; 王延忠; 王衍; 杨志辉

    2016-01-01

    With guar gum as a thickening agent,a water⁃based fracturing fluid is currently the most widely used fracturing fluid,but be⁃cause of guar gum containing a certain proportion of water⁃insoluble materials,broken plastic residues remain will harm the reservoir,e⁃ven seriously affecting the fracturing effect and injection⁃production capacity of the well.To solve at how the fracturing fluid without af⁃fecting the performance of the premise,while reducing the fracturing fluid formation damage problems,based on theoretical research,the authors analyzed the mechanism of the guanidine gum fracturing fluid thickening,crosslinking mechanism guar gum fracturing fluid;u⁃sing laboratory experiments as a means to develop a cross⁃linking can effectively reduce the amount of guar gum agonist.The use of the synergist fracturing fluid system,under the premise without affecting the fracturing fluid performance,can reduce the amount of guar gum from 30% to 50%,this has greatly reduced the damage of the reservoir caused by fracturing fluid residues and remains,and can reduce the cost.This research has important significance for the transformation of low permeability reservoir fracturing and shale reservoirs.%以胍胶为稠化剂的水基压裂液是目前油气层改造中应用最广泛的压裂液体系,但由于胍胶中含有一定比例水不溶物,破胶残渣滞留会对储层造成伤害,严重影响压裂效果和井的注采能力。为了解决在不影响压裂液性能的前提下,同时降低压裂液对地层的伤害问题,从理论研究着手,着重分析了压裂液中胍胶增黏机理、胍胶压裂液的交联机理;以室内实验为手段,开发出了一种可有效降低胍胶用量的交联增效剂。使用该增效剂的压裂液体系,在不影响压裂液性能的前提下,可降低胍胶用量30%~50%,大大降低了压裂液残渣滞留对储层造成的伤害,且可降低压裂液成本。该研究成果

  19. 瓜尔豆胶对莲子淀粉糊特性影响的研究%Influence of Guar Gum on the Characteristics of Lotus-Seed Starch Paste

    Institute of Scientific and Technical Information of China (English)

    林鸳缘; 曾绍校; 张怡; 郑宝东

    2011-01-01

    研究瓜尔豆胶对莲子淀粉糊化特性和冻融稳定性的影响.结果表明,添加瓜尔豆胶使莲子淀粉糊起糊温度降低,峰值黏度显著提高,热稳定性、冷稳定性均下降,且添加量越大影响越显著:当瓜尔豆胶添加量为0.5%时,淀粉凝沉性变化不大;瓜尔豆胶添加量为1%时,淀粉凝沉性减弱.瓜尔豆胶可大大降低莲子淀粉糊的析水率,提高莲子淀粉糊的冻融稳定性.%Effect of guar gum on pasting properties and freeze-thaw stability of lotus seed starch was investigated.The results showed that the beginning gelatinization temperature, heat and cold stability of lotus seed starch pastes decresed, the peak viscosity greatly increased with increasing the concentration of guar gum. However, guar gum had no effect in retarding retrogradation of lotus seed starch pastes at 0.5%, but at 1%, guar gum was highly effective in reducing the syneresis, improving the freeze-thaw stability of lotus seed starch pastes.

  20. Technological application of an extracellular cell lytic enzyme in xanthan gum clarification Aplicação tecnológica de uma enzima celulolítica para clarificação de goma xantana

    Directory of Open Access Journals (Sweden)

    Suresh Shastry

    2005-03-01

    Full Text Available An extracellular cell lytic enzyme from Pseudomonas sp. was active on heat killed cells of Xanthomonas campestris. The lytic activity caused enzymatic digestion of X.campestris xanthan gum. Digestion was effective for highly viscous native xanthan 2.0% (w/v and 2.5% (w/v commercial Sigma xanthan. Scanning electron microscopy and SDS-PAGE observations confirmed the cell lytic action on X.campestris cells.Uma enzima extracelular celulolítica produzida por Pseudomonas sp. foi ativa sobre células de Xanthomonas campestris mortas pelo calor. A atividade lítica causou a digestão enzimática de goma xantana de X. campestris. A digestão foi eficiente tanto para xantana nativa altamante viscosa (2,0% w/v como para xantana comercial Sigma (2,5% w/v. Observações por microscopia eletrônica de varredura demonstraram a ação celulolítica sobre células de X. campestris.

  1. Study on microwave-assisted synthesis of cationic guar gum%微波辅助阳离子瓜尔胶的合成研究

    Institute of Scientific and Technical Information of China (English)

    戴晓琳; 曹光群; 杨成

    2011-01-01

    以瓜尔胶为原料,3-氯-2-羟丙基三甲基氯化铵为醚化剂,氢氧化钠为催化剂,异丙醇作为溶剂,利用微波辅助合成了阳离子瓜尔胶.结果表明,在瓜尔胶醚化过程中使用微波辅助,反应时间是传统阳离子瓜尔胶合成方法的1/6,提高了反应效率.最佳反应条件为:溶剂选用85%异丙醇,微波功率300 W,微波辐射时间为30 min,反应温度40℃,醚化剂与瓜尔胶的物质的量比为0.25,碱与瓜尔胶的物质的量比为0.20.产物水溶性很好,可与表面活性剂复配.%Cationic guar gum(CGC) was obtained by means of microwave-irradiation using guar gum as raw materials,3-chloro-2-(hydroxypropyl) trimethylammonium chloride as cationic etherifying agent,sodium hydroxide as catalyst and isopropanol as solvent. Experimental results showed that comparing with traditional synthesis method,the reaction time decreased to 1/6 and the rate of reaction efficiency increased by using microwave. The synthesis conditions were optimized as follows: isopropanol as solvent, reaction power 300 W, reaction temperature 40 ℃ , radiation time 30 min, n (etherifying): n(CGG) = 0. 25, n(NaOH):n(CGG) =0.20. The product had good water-solubility and good compatibility with surfac tants.

  2. View registration of lobo-guará (Carnivore, Canidae, Chrysocyon brachyurus in the National Forest of Três Barras, SC

    Directory of Open Access Journals (Sweden)

    Anésio da Cunha Marques

    2009-12-01

    Full Text Available The lobo-guará is the major representative of the family of Canidae in South America. It lives in an open environment, such as fields and scrub. It is also found in nearby swamps and woods along the courses of water. This note narrates the viewing of an adult specimen of the lobo-guará in the National Forest (Flona of Ibama in Três Barras, SC (lat. 26º10’15”S; long. 50º10’15”W and elev. 750m that is characterized by remnants of Mixed Ombrofila Forest and presents huge areas with reforestation of Pinus sp. and Araucaria angustifolia of over 50 years of age. The Flona has an area of 4,458.5ha, with isotherms of 20 to 22ºC in January and 12 to 14ºC in July. The average annual relative humidity of the air is 85% and it precipitates between 1,200 and 1,400mm each year. The animal was seen many times in the morning by employees of Ibama at the end of July 2008 between the co-ordinates lat. 26º12’56”S long. 50º18’17”W and lat. 26º12’33”S long. 50º18’20”W. The individual was photographed for the fi rst time on July 3 at 7:30am and for the second time on July 19 at 7:48am for the same place, on the access road to Flona.

  3. Effect of the operating variables of a fluid catalytic cracking unit (FCC) on the naphtha gum formation; Efeito das variaveis operacionais de uma unidade de craqueamento catalitico (FCC) na formacao da goma na nafta

    Energy Technology Data Exchange (ETDEWEB)

    Mattos, Leandro Generoso de [PETROBRAS, Betim, MG (Brazil). Unidade de Negocio Refinaria Gabriel Passos (REGAP). Gerencia de Hidrotratamento e Coque]. E-mail: leandrogm@petrobras.com.br; Almeida, Gustavo Matheus de [Universidade de Sao Paulo (USP), SP (Brazil). Escola Politecnica. Dept. de Engenharia Quimica]. E-mail: gustavo@lscp.pqi.ep.usp.br; Oliveira, Eder Domingos de; Cardoso, Marcelo [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Quimica]. E-mails: eder@deq.ufmg.br; mcardoso@deq.ufmg.br

    2006-12-15

    One of the main problems brought by gasoline combustion in vehicles is the deposition of gum in the fuel system. Gum, though soluble in gasoline, appears in the form of a viscous residue after gasoline has evaporated. The carbon deposits coating carburetors, nozzles, collector pipes, intake valves and combustion chambers affect the car's steering capacity, lower the engine's performance and increase the emission of exhaust gas. Given the sort of refining used in Brazil, the content of naphtha resulting from catalytic cracking in gasoline coming from refineries is quite significant. The chains resulting from catalytic or thermal cracking processes have a strong tendency to form gum. In Fluid Catalytic Cracking (FCC), a complex network of chemical reactions takes place, which can either be catalytic or thermal. Principal Component Analysis techniques (PCA), stepwise regression and genetic algorithms have been used to select the operating variables of FCC that will bear the most influence on gum formation. An ARN (Artificial Neural Networks) software tool was also used to anticipate gum forming from operating variables selected by means of the above mentioned techniques. The results achieved in forecasting gum forming in cracked naphtha lead us to believe that the data analysis methodology used was suitable. It is possible to forecast potential gum through seven variables with a 10% Mean Relative Error (MRE) and a 1.75 g/100 mL Mean Absolute Error (MAE) with a linear correlation coefficient of 0.844; or through eight variables with an 11% MRE and a 1.93 g/100 mL MAE with a linear correlation coefficient of 0.829. In the first case, the methodology employed to reduce variables was stepwise regression, and in the second, genetic algorithms. (author)

  4. Biossíntese de goma xantana a partir da fermentação de soro de leite: rendimento e viscosidade Biosynthesis of xanthan gum from the fermentation of milk whey: productivity and viscosity

    Directory of Open Access Journals (Sweden)

    Tatiana Barreto Rocha Nery

    2008-01-01

    Full Text Available Xanthan is a polysaccharide synthesized by Xanthomonas bacteria and of extreme commercial importance as a microbial polysaccharide. The aim of this work was to produce xanthan using mozzarella cheese whey as substrate, by different isolates natives the Xanthomonas. The alternative medium for production was milk whey, urea and K2HPO4. The xanthan maximum productivity was 21.91 g L-1. Analysis of apparent viscosity was made in solutions of gum at 0.5-2.0%, 25-65 ºC with shear rate of 25-1000 s-1.The maximum viscosity found was 57.30 mPa.s. The isolates demonstrate capacity to degrade the lactose and to produce xanthan, being constituted an alternative for the industrial production.

  5. Research on Soy Protein Isolate-guar Gum Blending Composite Membrane%大豆分离蛋白-瓜尔胶共混复合膜的研究

    Institute of Scientific and Technical Information of China (English)

    隋春霞; 于国萍

    2011-01-01

    文章以大豆分离蛋白作为成膜基质,添加天然高分子材料瓜尔胶作为共混物,通过变化大豆分离蛋白、瓜尔胶间量的关系以及改变甘油含量,结合调节共混溶液pH,研究在不同条件下获得复合膜的抗拉强度和断裂伸长率.%This paper attempts to research the changes of tensile strength and breaking elongation from a serial of blend membranes with soy protein isolate as film substrate. which are mixed by adding a natural polymer material-guar gum, changed the contents of glycerol, proportion of guar gum and soy protein isolate, pH.

  6. Ocorrência (novo registro de lobo-guará chrysocyon brachyurus (Illiger, 1815 (carnivora, canidae no sul do Brasil

    Directory of Open Access Journals (Sweden)

    Leandro Chisté Pinto

    2013-03-01

    Full Text Available http://dx.doi.org/10.5902/198050988459No presente estudo é apresentado o registro da ocorrência de Chrysocyon brachyurus (Illiger 1815 em uma área de campo úmido adjacente a faixa de mata ciliar do rio Ibicuí, estado do Rio Grande do Sul, Brasil. A espécie foi encontrada através do uso de armadilhas fotográficas e da procura de vestígios em transecções pré-estabelecidas na área, como parte de um programa de monitoramento ambiental de um projeto silvicultural.

  7. Influência da mono-hidrogenação da fração C5 na síntese do TAME usando Amberlyst 15 como catalisador

    Directory of Open Access Journals (Sweden)

    Gilberto da Cunha Gonçalves

    2001-05-01

    Full Text Available No presente trabalho, foi estudada a síntese do TAME, em fase líquida, a partir de uma fração C5 e metanol, utilizando Amberlyst 15 como catalisador. A fração C5 utilizada possui uma diolefina, que tem uma alta tendência à formação de gomas e um alto teor de mono-olefinas. Deste modo, o objetivo deste trabalho foi avaliar o efeito da mono-hidrogenação da fração C5 na síntese do TAME. A hidrogenação foi feita a 80oC e 10 kgf/cm2 de H2, usando um catalisador 0,3% Pt/Al2O3. A diolefina foi totalmente hidrogenada e o teor de mono-olefinas significativamente reduzido sem um decréscimo apreciável no teor de isoamilenos reativos. A eterificação foi feita em um reator tipo batelada de 250 mL, com agitação magnética. A temperatura foi variada na faixa de 50 a 90oC, com uma pressão de 10 kgf/cm2 e razão molar isoamileno/metanol de aproximadamente um. Os produtos de reação foram analisados por cromatografia gasosa. A conversão total observada foi aproximadamente a mesma para o os cortes original e mono-hidrogenado. Entretanto, os produtos obtidos utilizando a fração C5 original apresentaram cheiro forte e coloração, mesmos para os testes a temperaturas mais baixas, que são características da formação de gomas. Por outro lado, quando a fração mono-hidrogenada foi usada na eterificação, o cheiro forte e coloração não foram observados. Portanto, a mono-hidrogenação da fração C5 contendo os isoamilenos reativos é necessária para que o TAME produzido na reação de eterificação possa ser adicionado à gasolina

  8. N,N-二乙基胺乙基取代瓜尔胶的合成及结构表征%Synthesis and structural characterization of N, N-diethylaminoethyl guar gum

    Institute of Scientific and Technical Information of China (English)

    邓明宇; 周利英; 宋建锋; 孙雪莲; 何建平; 尹恒; 叶应庆

    2012-01-01

    在碱催化条件下,利用N,N-二乙基氯乙胺盐酸盐与瓜尔胶和羟丙基瓜尔胶一步法合成得到N,N-二乙基胺乙基瓜尔胶和N,N-二乙基胺乙基羟丙基瓜尔胶.结果显示合成过程中温度、反应时间、羟丙基取代度及溶剂等因素对产品分子量和N,N-二乙基胺乙基取代度有影响.通过红外光谱和核磁法对N,N-二乙基胺乙基瓜尔胶和羟丙基N,N-二乙基胺乙基瓜尔胶的分子结构进行了分析,并通过碳谱对N,N-二乙基胺乙基在瓜尔胶分子链中糖环上的取代分布进行了分析.%In the base-catalyzed conditions,N,N-diethylaminoethyl guar gum and N,N-diethyl amino ethyl hydroxypropyl guar gum were synthesized by one-step process. On the basis of investigation on reaction factors such as the reaction temperature,the reaction time,MS of HPG and solvent on the molecular weight of products and MS of N,N-diethylamido ethyl,the proper synthetic condition was obtained. Using NMR analysis technique, MS and DS of N, N-diethyLamino ethyl guar gum and N, N-diethylamino ethyl hydroxypropyl guar gum were determined.

  9. Propriedades físicas de misturas para sherbet de mangaba Physical properties of mixes to mangaba sherbet

    Directory of Open Access Journals (Sweden)

    Alessandra Lopes de Oliveira

    2005-06-01

    Full Text Available O objetivo deste trabalho foi avaliar a viscosidade, a quantidade de água não congelada (w nc e a temperatura de transição vítrea da fração maximamente crioconcentrada (Tg' de misturas para sherbet, e a incorporação de ar (IAr dos sherbets, com diferentes concentrações de goma guar (0,2% a 0,5% e polpa de mangaba (21,1%, 25,8% e 28,6%. A viscosidade aparente variou de 85,8 a 286,1 cP, aumentando com as concentrações de goma guar e mangaba. As análises térmicas com calorímetro diferencial de varredura mostraram que a w nc variou entre 12% e 20%, diminuindo com o aumento da concentração de polpa. A Tg' variou de -57,65ºC a -53,45ºC e não apresentou diferença entre as amostras. A IAr foi de 20,01% a 40,59%. Sherbets com a mesma concentração de polpa apresentaram valores diferentes desta variável, mas uma relação entre o aumento da quantidade de goma guar e maior IAr foi observada somente para os sherbets com 25,8% de polpa. O estabilizante interfere na viscosidade da mistura e IAr, e a concentração de polpa influencia as propriedades térmicas. O aumento de IAr proporciona melhor maciez ao produto. Maior quantidade de polpa diminui a w nc, assim o produto terá menos água disponível para migrar e formar cristais de gelo maiores durante as oscilações na temperatura, diminuindo a qualidade do produto.Viscosity, unfrozen water (w nc and glass transition temperature of the maximally freeze-concentrated material (Tg' of sherbet mixtures and the overrum of the sherbets with different concentrations of guar gum (from 0.2% to 0.5% and mangaba pulp (21.1%, 25.8% and 28.5% were evaluated. Apparent viscosity ranged from 85.8 to 286.1 cP, increasing with guar gum concentration and mangaba pulp. Thermal analysis using differential scanning calorimetry of sherbets mixture showed that w nc was from 12% to 20%, decreasing with the increasing of mangaba pulp concentration. The Tg' ranged from -57.65ºC to -53.45ºC and was not

  10. Preparation of Quick-Dissolving Guar Gum and its Application in Papermaking%速溶型瓜尔胶的制备及在造纸中的应用1

    Institute of Scientific and Technical Information of China (English)

    赵昱; 龙柱; 王长红; 邓海波

    2016-01-01

    对瓜尔胶原粉进行处理制备速溶型瓜尔胶,并将其应用于造纸。实验结果表明,速溶型瓜尔胶具有较快的水合速率,30 min即可达到最大黏度的96.4%,造纸应用抗张指数可提高21.3%,耐破指数提高38.1%,撕裂指数提高22.2%。%To deal with collagen guar gum powder, the quick-dissolving guar gum was prepared, and applied to papermaking. The result showed that the quick-dissolving guar gum with faster hydration rate, 96.4%of the 30 min could achieve maximum viscosity, paper application could improve the tensile index by 21.3%, improve resistance index by 38.1%and improve the tear index by 22.2%.

  11. 磺酸基羟丙基瓜尔胶的制备和性能%PREPARATION AND PROPERTIES OF SULFONIC ACID HYDROXYPROPYL GUAR GUM

    Institute of Scientific and Technical Information of China (English)

    曹军胜; 龙柱; 朱莹

    2011-01-01

    以3-氯-2-羟基丙磺酸钠,瓜尔胶原粉为原料,在碱性催化剂作用下采用湿法合成了磺酸基羟丙基瓜尔胶.讨论了外加盐、酸度、取代度和不同浓度的瓜尔胶水溶液对磺酸基羟丙基瓜尔胶流变曲线的影响,并通过红外光谱,扫描电镜,核磁图谱,XRD等进行了分析.结果发现,随着外加盐浓度的增大,表观黏度逐渐减小,表现出明显的聚电解质的通性,AlCl3> MgCl2> NaC1.随着酸度的增大,表观黏度在pH值约为7时达到最大,随后减小趋势趋于平缓,表明对酸的敏感程度远远大于对碱的敏感程度;随着取代度的增大,水不溶物含量和表观黏度逐渐减小,在取代度超过0.3的时候,减小趋势趋于平缓;随着剪切速率的增大,表观黏度逐渐减小.%Sulfonic acid hydroxypropyl guar gum (SHGG) was prepared in laboratory by a wet process based on the reaction of guar gum and sodium 3-chloro-2-hydroxy propanesulfonate with an alkali catalyst. The effects of SHGG aqueous solution, including electrolyte added, acidity, substitution degree and concentration on the rheology properties of SHGG were investigated. The structure of the guar gum product was characterized by IR, SEM, NMR, XRD, and DSC. The results showed that SHGG aqueous solution had the behaviors of typical polymerizing-electrolyte. Additionally, the effect of the high metal ion was bigger than that of low metal ion: AlCl3>MgCl2>NaCl. The viscosity of SHGG aqueous solution decreased with increasing the concentration of electrolyte. With the acidity increased, the apparent viscosity reached the maximum about pH 7. 0, and then decreased slightly, showing that the sensibility of SHGG aqueous solution to acid is more pronounced than that to alkali. The insoluble residue and the apparent viscosity reduced following the substitution degree increased. When the substitution degree was greater than 0. 3, the tendency became gentle. The apparent viscosity decreased with

  12. Efecto de la concentración de goma de semillas de mezquite y proteínas de soya en la microestructura de coágulos obtenidos de leche

    Directory of Open Access Journals (Sweden)

    Araceli Hernández T.

    2003-01-01

    Full Text Available Desde hace algunas décadas y por muchas razones, existe el interés por la incorporación de biopolímeros en la matriz de caseína, tales como proteínas y polisacáridos. Dicho proceso ha logrado aumentar rendimientos, reducir calorías o desarrollar atributos especiales. En la mayoría de los casos, esta adición se hizo mezclando los biopolímeros en coágulos de leche previamente obtenidos. El artículo trata acerca de la incorporación de la goma de semillas de mezquite (GSMez y las proteínas de soya (PS en la leche antes de la coagulación y su efecto sobre la matriz protéica de caseína. Lo anterior se realizó por método enzimático, con cuajo líquido microbiano. Se emplearon concentraciones de 0.15 y 0.45 % (p/v para GSMez y de 0.6 y 1.5 % (p/v para PS. Se observó que conforme se incrementaba la concentración de GSMez y de PS se dificultaba más la coagulación y había formación de cúmulos de caseína más pequeños. Tanto la GSMez como la PS presentaron concentración crítica arriba de la cual no se produce la coagulación, lo que genera una suspensión arenosa. Los coágulos prensados de GSMez, obtenidos justo en concentración crítica, mostraron una apariencia suave y húmeda, mientras que los adicionados de PS, destacan por su apariencia seca, dura y arenosa. Las observaciones concluyeron que tanto la GSMez como la PS producen un impedimento de tipo estérico que no permite la correcta adhesión de las caseínas para formar el coágulo. Este efecto limita el uso de estos biopolímeros a concentraciones mayores de 0.15% (p/v para GSMez y 0.6 % (p/v para PS

  13. Problemas da sociologia da arte

    OpenAIRE

    Bastide, Roger

    2006-01-01

    A partir de um balanço das realizações consideradas pelo autor como as mais relevantes no campo da sociologia da arte até o final dos anos de 1940, o texto propõe novos rumos para a disciplina, considerando o modo como a arte é socialmente produzida como linguagem e valor.

  14. Aislamiento y caracterización parcial de heterofilina, una nueva lectina de semillas de Artocarpus heterophyllus

    OpenAIRE

    Veras Mourao, Rosa Helena; Filho, José Xavier; Alves,Elias Walter; Orellano Elena Graciela; Fernandes de Melo, Dirce; Farías de Aragao, María Erivalda; Silva Lima, María da Guia; Prouvost-Danon, Annie

    1999-01-01

    Fueron aisladas cuatro (4) lectinas presentes en las semillas de Artocarpus heterophyllus Lamk. ("jaca") mediante el uso de criterios de solubilidad y varias cromatografias de afinidad: goma de guar, quitina y agarosa-D-manosa. De las dos lectinas que tuvieron afinidad a la goma de guar, una se comportó como albúmina (AII) y fue identificada como la bien conocida lectina "jacalina" por su especificidad al azúcar, movilidad electroforética y secuencia de aminoácidos en el extremo N-terminal. L...

  15. 低表面张力ASA改性瓜尔胶表面施胶剂的制备及其应用%Preparation and Application of Surface Sizing Agent with Low Surface Tension of Guar Gum Modified by ASA

    Institute of Scientific and Technical Information of China (English)

    杨晓武; 沈一丁; 李培枝; 薛贝

    2012-01-01

    采用烯基琥珀酸酐(ASA)对瓜尔胶原粉进行改性来制备一种环境友好型表面施胶剂,对纸张进行表面施胶并对其施胶效果进行了测定。讨论了瓜尔胶与ASA的用量比例、反应温度及反应时间等对施胶效果的影响,同时采用红外光谱(FT-IR)、X射线衍射(XRD)和动态接触角(DCA)等测试手段对其结构、性能和应用效果进行了表征。结果表明,当瓜尔胶原粉与ASA比例为7:1,反应温度为60℃,反应时间为10h,在瓜尔胶分子上成功引入疏水性长链,改性瓜尔胶表面施胶浓度为2.5%时,纸张的施胶度可以达到54S,动态接触角可达118°以上。%In order to prepare a kind of environment-friendly surface sizing agent, the guar gum was modified by alkenyl succinic anhydride (ASA), and the surface sizing effect of the modified guar gum was studied. ~ae effect on surface sizing of the reactant ratio, reaction temperature and reaction time were discussed, and the structure, performance and application effect were characterized by the infrared spectrum (FT-IR), X-ray diffraction (XRD), dynamic contact angle (DCA) and so on. ]-he results showed that when the ratio of the guar gum and ASA was 7:1, reaction temperature was 60~C, reaction time was 10 hours, the hydrophobic long chain was introduced onto the guar gum successfiaUy. As the dosage of modified guar gum was 2.5%, the sizing degree was up to 54 seconds, and the dynamic contact angle was more than 118°.

  16. Influence of the addition orders of guar gum and tannic acid on sulfide flotation%古尔胶和鞣酸添加方式对硫化矿浮选的影响

    Institute of Scientific and Technical Information of China (English)

    邱仙辉; 孙传尧

    2014-01-01

    通过浮选实验研究了两种不同结构的有机抑制剂古尔胶和鞣酸以及这两种药剂与乙基黄药不同添加顺序对方铅矿、黄铜矿及黄铁矿浮选行为的影响。当先加入古尔胶时,古尔胶对三种硫化矿抑制作用较强;而古尔胶后于乙基黄药加入时,古尔胶对三种硫化矿的抑制作用明显减弱。鞣酸与乙基黄药不同的添加顺序不影响鞣酸对黄铁矿和方铅矿的抑制作用。紫外光谱研究表明,古尔胶对乙基黄药在三种硫化矿表面吸附没有影响,而鞣酸能够阻碍乙基黄药在硫化矿表面吸附。红外光谱研究表明,鞣酸通过化学作用吸附在方铅矿表面,因此能够抑制吸附了乙基黄药的硫化矿。%The effects of two types of organic depressants, guar gum and tannic acid, on the flotation of galena, chalcopyrite and pyrite were investigated using micro-flotation tests, and different addition orders of the two reagents and ethyl xanthate were also stud-ied. When guar gum is added first, its depression effect on sulfides is considerable;but when ethyl xanthate is added first, guar gum has little depression effect on sulfide flotation. Tannic acid depresses pyrite and galena whatever addition order of ethyl xanthate. The interaction between guar gum or tannic acid and ethyl xanthate on the sulfide surface was studied by UV spectroscopy. It is indicated that guar gum has no impact on the adsorption of ethyl xanthate on the sulfide surface, while tannic acid can prevent the adsorption of ethyl xanthate. Infrared spectroscopy analysis suggests that tannic acid adsorbs on the galena surface by chemical action, which is the reason that tannic acid can depress sulfides adsorbing ethyl xanthate.

  17. 磷酸酯型两性瓜尔胶的合成及增强性能研究%Synthesis of Amphoteric Guar Gum Derivative Containing Phosphate Group and Its Strengthening Effect

    Institute of Scientific and Technical Information of China (English)

    万小芳; 李友明; 陈金中; 林胜任

    2009-01-01

    The amphoteric guar gum derivative containing phosphate and quaternary-amine groups was synthesized in isopropanol solvent. An- ionic phosphate was introduced at first through the homemade anionic intennedium reagent and then cationic groups were grafted at the pres- ence of cationic etherifying agent. The anionic intermedium reagent and guar gum derivative were characterized by1H-NMR. The effects of re- action temperature, anionic/cationic reagent doses and NaOH dose on P/N conent of the purified product were investigated. The optimal conditions were obtained as follows: reaction temperature 60℃, 5% dose of NaOH (on guar gum content)at etberification process, 15%/ 28% doses of anionic/cationic reagent. Meanwhile the P/N contents in the guar gum derivative reach 0.44% and 0.8%. When the product is used in ONP system, it exhibits better ability in increasing handsheets' strength properties in comparison with amphoteric starch which has been using in the industry. This guar gum derivative can increase the surface strength by 24.5% (compared with the control sample)at the dosage of 0.2%.%以异丙醇为溶剂,采用先阴离子化后阳离子化工艺合成了含磷酸酯和季铵基团的两性瓜尔胶,并通过1H-NMR证实自制阴离子中间体和两性瓜尔胶的官能用结构.研究了反应温度,阴离子中间体、阳离子单体、碱用量对产物的磷、氮含量的影响,确定优化条件为:反应温度60℃、醚化时NaOH用晕5%、阴离子中间体及阳离子单体用量分别为15%和28%,此时产物的磷和氮含量分别为0.44%和0.8%.该新型两性瓜尔胶用于ONP浆体系,能明显提高手抄片的强度性能,当其用量为0.2%时可使印刷表面强度提高24.5%,优于工厂现用两性淀粉.

  18. 离子液体的合成及其对瓜尔胶的溶解性能%Synthesis of ionic liquids and its application for dissolving guar gum

    Institute of Scientific and Technical Information of China (English)

    周静; 杜彬; 彭树华; 何建平; 邓明宇; 王克

    2013-01-01

    l-allyl-2-isoallyl-4, 5-dihydro-imidazole chloride ( AihimCl) , l-butyl-2-isoallyl-4, 5-dihydro-imidazole chloride ( Bi-himCl) , l-hexyl-2-isoallyl-4, 5-dihydro-imidazole chloride ( HihimCl ) and 1-octyl-2-isoallyl-4, 5-dihydro-imidazole chloride (OihimCl)were synthesized as solvent for guar gum. Their chemical structures were characterized by FT-IR,1H NMR and 13C NMR. The solubility of guar gum in the ionic liquids was investigated by means of polarizing optical microscopy (POM). The solubility of guar gum in BihimCl was up to 5. 5%. The dissolution velocity of guar gum in BihimCl and OihimCl was higher than that in AihimCl and HihimCl. After 6 hours guar gum could be dissolved completely.%本文合成了氯化1-烯丙基-2-丙烯基-4,5-二氢化咪唑(AihimCl),氯化1-丁基-2-丙烯基-4,5-二氢化咪唑(BihimCl),氯化1-己基-2-丙烯基4,5-二氢化咪唑(HihimCl),氯化1-辛基-2-丙烯基-4,5-二氢化咪唑(OihimCl)四种离子液体;并用傅立叶转换红外光谱(FT-IR),核磁共振氢谱(1H NMR)和碳谱(13C NMR)表征了其结构;研究了这四种离子液体对瓜尔胶(GG)的溶解性,并用偏光显微镜观察了其溶解过程,瓜尔胶在BihimCl中的溶解度可达5.5%;比较了瓜尔胶在四种离子液体中的溶解速度,在BihimCl和OihimCl中的溶解速度比在AihimCl和HihimCl中快,6小时后都能够完全溶解.

  19. Adsorption isotherms, kinetics and thermodynamic studies towards understanding the interaction between cross-linked alginate-guar gum matrix and chymotrypsin.

    Science.gov (United States)

    Woitovich Valetti, Nadia; Picó, Guillermo

    2016-02-15

    The adsorption kinetics of chymotrypsin, a pancreatic serine protease, onto an alginate-gum guar matrix cross-linked with epichlorohydrin has been performed using a batch-adsorption technique. The effect of various experimental parameters such as pH, salt presence, contact time and temperature were investigated. The pseudo-first-order and pseudo-second-order kinetic models were used to describe the kinetic data which shows that the adsorption of the enzyme followed the pseudo-second-order rate expression. The Langmuir, Freundlich and Hill adsorption isotherm models were applied to describe the equilibrium isotherms, and the isotherm constants were determined. It was found that Hill model was more suitable for our data because the isotherm data showed a sigmoidal behavior with the free enzyme concentration increasing in equilibrium. At 8°C and at pH 5.0, 1g hydrate matrix adsorbed about 7mg of chymotrypsin. In the desorption process 80% of the biological activity of chymotrypsin was recovered under the condition of 50mM phosphate buffer, pH 7.00-500mM NaCl. When successive cycles of adsorption/washing/desorption were performed, it was observed that the matrix remained functional until the fourth cycle of repeated batch enzyme adsorption. These results are important in terms of diminishing of cost and waste generation.

  20. Microencapsulation of grape (Vitis labrusca var. Bordo) skin phenolic extract using gum Arabic, polydextrose, and partially hydrolyzed guar gum as encapsulating agents.

    Science.gov (United States)

    Kuck, Luiza Siede; Noreña, Caciano Pelayo Zapata

    2016-03-01

    Bordo grape skin extract was microencapsulated by spray-drying and freeze-drying, using gum arabic (GA), partially hydrolyzed guar gum (PHGG), and polydextrose (PD) as encapsulating agents. Total phenolics and total monomeric anthocyanin, antioxidant activity, color, moisture, water activity (aw), solubility, hygroscopicity, glass transition temperature (Tg), particle size, and microstructure of the powders were evaluated. The retention of phenolics and anthocyanins ranged from 81.4% to 95.3%, and 80.8% to 99.6%, respectively, while the retention of antioxidant activity ranged from 45.4% to 83.7%. Treatments subjected to spray-drying had lower moisture, aw, and particle size, and greater solubility, while the freeze-dried samples were less hygroscopic. Tg values ranged from 10.1 to 52.2°C, and the highest values corresponded to the spray-dried microparticles. The spray-dried particles had spherical shape, while the freeze-dried powders showed irregular structures. The spray drying technique and the use of 5% PHGG and 5% PD has proven to be the best treatment.

  1. Guar gum: Structural and electrochemical characterization of natural polymer based binder for silicon-carbon composite rechargeable Li-ion battery anodes

    Science.gov (United States)

    Kuruba, Ramalinga; Datta, Moni Kanchan; Damodaran, Krishnan; Jampani, Prashanth H.; Gattu, Bharat; Patel, Prasad P.; Shanthi, Pavithra M.; Damle, Sameer; Kumta, Prashant N.

    2015-12-01

    Long term cyclability of a composite Li-ion anode electrode comprised of 82 wt.% Si/C lithium ion active material along with 8 wt.% polymeric binder and 10 wt.% Super P conductive carbon black has been studied utilizing polymeric binders exhibiting different elastic/tensile moduli and tensile yield strengths. Accordingly, electrochemically active Si/C composite synthesized by high energy mechanical milling (HEMM), exhibiting reversible specific capacities of ∼780 mAh/g and ∼600 mAh/g at charge/discharge rates of ∼50 mA/g and ∼200 mA/g, respectively were selected as the Li-ion active anode. Polyvinylidene fluoride (PVDF) and purified guar gum (PGG) with reported elastic moduli ∼1000 MPa and ∼3200 MPa, respectively were selected as the binders. Results show that the composite electrode (Si/C + binder + conducting carbon) comprising the higher elastic modulus binder (PGG) exhibits better long term cyclability contrasted with PVDF. 1H-NMR analysis of the polymer before and after cycling shows structural degradation/deformation of the low elastic modulus PVDF, whereas the high elastic modulus PGG binder shows no permanent structural deformation or damage. The results presented herein thus suggest that PGG based polymers exhibiting high elastic modulus are a promising class of binders with the desired mechanical integrity needed for enduring the colossal volume expansion stresses of Si/C based composite anodes.

  2. Maintenance Therapy with Partially Hydrolyzed Guar Gum in the Conservative Treatment of Chronic Anal Fissure: Results of a Prospective, Randomized Study

    Directory of Open Access Journals (Sweden)

    Antonio Brillantino

    2014-01-01

    Full Text Available Purpose. This study was designed to evaluate the role of maintenance therapy with partially hydrolyzed guar gum (PHGG after topical application of glyceryl trinitrate (GTN in the conservative treatment of chronic anal fissure (CAF. Methods. From all the patients with CAF observed during the study period, 165 subjects with healed CAF after standard therapy with topical GTN 0.4% ointment were randomized to receive (group II or not (group I maintenance therapy with PHGG for 10 months. Clinical and manometric followup was carried out 6 and 12 months after treatment. Results. At six-month followup, median visual analogue scale score was significantly higher in group I if compared with group II. The success and recurrence rate at 12-month followup were, respectively, 38.3% (28/73 in group I versus 58.5% (41/70 in group II (P=0.019; Fisher’s exact test and 30.2% (13/43 in group I versus 14.5% (7/48 in group II (P=0.0047; Fisher’s exact test. Conclusion. The maintenance therapy with PHGG in patients with healed CAF after chemical sphincterotomy by topical application of GTN 0.4% ointment seems associated with a significant reduction of recurrence rate and with a significant increase of success rate at 12-month followup.

  3. Formulação de meios de cultivo à base de soro de leite para a produção de goma xantana por X. Campestris C7L Formulation of whey-based media for xanthan gum production by X. Campestris C7L isolate

    Directory of Open Access Journals (Sweden)

    Marcia NITSCHKE

    2001-01-01

    Full Text Available A goma xantana é um polissacarídeo microbiano de grande significado comercial especialmente para a indústria de alimentos. O objetivo deste trabalho foi avaliar a produção de xantana em diferentes meios de cultura à base de soro de leite utilizando o isolado Xanthomonas campestris C7L. Dentre as formulações testadas o meio de soro de leite integral produziu maior viscosidade e concentração final de xantana. Um sistema combinando soro integral (0,35% de proteína e soro filtrado (0,18%de proteína foi proposto. Na primeira fase em soro integral a produção de xantana foi de 13g/L e 45% de rendimento,enquanto que na segunda fase utilizando-se soro filtrado obteve-se um total de 28g/L de xantana e 75% de rendimento. O rendimento geral do processo foi de 55% e a viscosidade final do meio atingiu 18000cP. As soluções de xantana produzidas em soro de leite apresentaram comportamento pseudoplástico e tixotrópico característicos deste tipo de polímero. O isolado C7L demonstrou capacidade de produzir gomas de alta viscosidade e qualidade em soro de leite, constituindo uma alternativa promissora para a produção industrial de goma xantana a partir deste subproduto.Xanthan gum is a microbial polysaccharide of great commercial interest, especially in the food industry. The aim of this work was the evaluation of xanthan gum production from different whey - based media by a lactose utilizing Xanthomonas campestris C7L isolate. Three whey media formulations were tested: unfiltered whey, filtered whey and hydrolyzed whey. The medium composed of unfiltered whey showed the highest viscosities and xanthan concentrations. A two stage fermentation strategy, combining unfiltered whey (0,35% protein and filtered whey (0,18% protein, was proposed. The first stage, using unfiltered whey medium, showed a xanthan production of 12g/L and a 45% yield. The second stage, with filtered whey addition, gave final xanthan concentration of 28g/L and a 75% yield

  4. Evolving Service Poles in Presence Missions.

    Science.gov (United States)

    1995-08-01

    pressure the government of Haiti. 98 94 7 Zaire U.S. Army and Air Force personnel began Operation SUPPORT HOPE in Goma , Zaire in an effort to...takes with Colombia. Tta CoaSt GuarS hefe shioS.^nUnder «■««»«*<» Venezuela, and a oureulr «^ „._ shipboarding agreement with Barbuda, ’A ^SSStl

  5. 疏水缔合改性羟丙基瓜尔胶的合成工艺%RESEARCH ON THE SYNTHESIS OF HYDROPHOBICALLY ASSOCIATING HYDROXYPROPYL GUAR GUM

    Institute of Scientific and Technical Information of China (English)

    赵修太; 仇东旭; 宋丽; 孙昆

    2011-01-01

    The paper studied the reaction of the active hydroxyl of molecular chain in hydroxypropyl guar gum (HPG) with 1-bromo dodecane molecule for the preparation of hydrophobically modified hydroxypropyl guar gum (BD-HAHPG) through the introduction of long-chain hydrophobic monomers to hydrophilic hydroxypropyl guar gum molecular chain. The optimum conditions of synthesis have been obtained as follows: reaction temperature 80 ℃, the concentration of active agent 2.0%,the concentration of HPG 9.0%, the concentration of 1-bromo dodecane 1.7%, and the reaction time 6 h. The results of rheological property showed that BD-HAHPG had viscosity increasing, thermalresistance, salt-tolerance and shear resistance properties.%实验以羟丙基瓜尔胶(HPG)分子链上的活泼羟基与1-溴代十二烷的大分子反应,将长链疏水单体引入羟丙基瓜尔胶的亲水分子链上,制备疏水缔合改性羟丙基瓜尔胶(BD-HAHPG).讨论了工艺条件对增黏性能的影响,实验结果表明,其最佳合成工艺条件为:反应温度80℃,w(氢氧化钠)=2.0%,w(HPG)=9.0%,w(1-溴代十二烷)=1.7%,反应时间6 h.经流变性能测试,BD-HAHPG具有一定的增黏性、耐温抗盐性和耐剪切性.

  6. 改性胍胶水煤浆分散剂的制备与性能表征%Synthesis and Propertis of Modified Guar Gum Dispersant for Coal-water Slurry

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Modified guar gum dispersant was synthesized with guar gum as based agent, acrylic aid, AMPS and AM as modifying agents.The structure of the dispersant was characterized by means of Fourier transform infrared spectrometry (FTIR), thermal gravimetric analysis (TG).The properties of the coal-water slurry with the dispersant were measured by rheometer and zetasizer. The results show that modified guar gum dispersant starts to decompose at 280 ℃;the viscosity of the system is 760 mPa·s when the dispersant dosage is 0.4% and the pulp concentration is 64%;the condensate rate of the coal-water slurry is less, and the system is stable.%以胍胶为主剂,经过氧化还原反应后在分子链上引入含有羧基的丙烯酸、含有磺酸基的2-丙烯酰胺-2-甲基丙磺酸(AMPS)和丙烯酰胺分子单体,通过自由基缩合反应合成出改性胍胶聚合物分散剂,通过红外光谱、热分析仪、流变仪及激光粒度仪对合成产物及水煤浆体系进行测试,改性胍胶聚合物分散剂在280℃开始逐级分解,热稳定性较好;在分散剂加量为0.4%,制浆浓度为64%时,水煤浆体系的表观粘度为760 mPa·s,水煤浆析水量较少、体系稳定。

  7. Disclosure of HIV status and its impact on the loss in the follow-up of HIV-infected patients on potent anti-retroviral therapy programs in a (post-) conflict setting: A retrospective cohort study from Goma, Democratic Republic of Congo

    Science.gov (United States)

    Akilimali, Pierre Zalagile; Musumari, Patou Masika; Kashala-Abotnes, Espérance; Kayembe, Patrick Kalambayi; Lepira, François B.; Mutombo, Paulin Beya; Tylleskar, Thorkild; Ali, Mapatano Mala

    2017-01-01

    Background The study aimed to identify the impact of non-disclosure of HIV status on the loss to follow-up (LTFU) of patients receiving anti-retroviral therapy. Methodology A historic cohort of HIV patients from 2 major hospitals in Goma, Democratic Republic of Congo was followed from 2004 to 2012. LTFU was defined as not taking an ART refill for a period of 3 months or longer since the last attendance, and had not yet been classified as ‘dead’ or ‘transferred-out’. Kaplan-Meier plots were used to determine the probability of LTFU as a function of time as inclusive of the cohort. The log-rank test was used to compare survival curves based on determinants. Cox proportional hazard modeling was used to measure predictors of LTFU from the time of treatment induction until December 15th, 2012 (the end-point). Results The median follow-up time was 3.99 years (IQR = 2.33 to 5.59). Seventy percent of patients had shared their HIV status with others (95% CI: 66.3–73.1). The proportion of LTFU was 12% (95%CI: 9.6–14.4). Patients who did not share their HIV status (Adjusted HR 2.28, 95% CI 1.46–2.29), patients who did not live in the city of Goma (Adjusted HR 1.97, 95% CI 1.02–3.77), and those who attained secondary or higher education level (Adjusted HR 1.60, 95% CI 1.02–2.53) had a higher hazard of being LTFU. Conclusion This study shows the relationship between the non–disclosure HIV status and LTFU. Healthcare workers in similar settings should pay more attention to clients who have not disclosed their HIV status, and to those living far from health settings where they receive medication. PMID:28170410

  8. Technology research of the recycled low molecular guar gum f racturing fluid%可回收再利用的低分子胍胶压裂液技术研究

    Institute of Scientific and Technical Information of China (English)

    熊颖; 刘友权; 石晓松; 张永国; 吴文刚; 黄晨直; 陈楠

    2014-01-01

    To solve the problems of water shortage in fracturing operation and fracturing out-let liquid handling difficulty ,the borate dissociation equilibrium principle is controlled by pH val-ue to change the crosslinked state of guar gum fracturing fluid for the degradability of gel break-ing under acidic condition .The molecular structure of guar gum is not damaged ,so it can be crosslinked again .This paper used the biodegradation technology to degrade guar gum ,and con-trolled the molecular weight of the guar gum by controlling the degradation conditions to control the degree of degradation of guar gum ,eventually a low molecular crosslinked guar gum have been developed with molecular weight from 30 × 104 to 50 × 104 under the condition of borate . The viscosity of aqueous solution of the low molecular guar gum was low ,and the water insoluble content was less than or equal to 4% .Taking a solid acid as a capsule core ,a polymer being grad-ually dissolved in the w ater as the capsule dressing ,a capsule breaker have been prepared using the method of air suspension film .The capsule breaker is not acidic on the ground for ensuring the fracturing fluid to be crosslinked well ,and under formation temperature and pressure condi-tions the capsule breaker can gradually release the solid acid for the fracturing fluid degradability gel breaking .Taking the low molecular guar gum as the thickening agent ,the capsule breaker parceling solid acid as the breaker ,a recycled low molecular guar gum fracturing fluid has been developed .The fracturing fluid has been widely used in Sichuan Xu Jiahe reservoir reconstruction ,and a lot of fracturing outlet liquids have been recycled .The effect of energy conservation and emissions reduction is remarkable .%为解决压裂作业水资源缺乏和返排液难处理的问题,利用pH值控制硼酸盐离解平衡移动原理来改变胍胶压裂液的交联状态,使其在酸性条件下非降解性破胶,胍胶分子结构

  9. 氯化钠和氯化钙对玉米淀粉-瓜尔胶复配体系的影响%Effects of Sodium Chloride and Calcium Chloride on Corn Starch and Guar Gum Mixed System

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

      通过测定分析玉米淀粉-瓜尔胶复配体系在有无氯化钠和氯化钙存在条件下的糊化特性、动态与静态流变学特性,研究氯化钠和氯化钙对玉米淀粉-瓜尔胶复配体系的影响。结果表明,氯化钠和氯化钙的加入,提高了玉米淀粉-瓜尔胶复配体系的成糊温度,降低了崩解值和回升值,峰值黏度也略微下降;玉米淀粉-瓜尔胶复配体系的弹性模量G′值显著减小,黏性模量G″值的频率依赖性较大;氯化钠和氯化钙使玉米淀粉-瓜尔胶复配体系的假塑性增强,且氯化钙的作用大于氯化钠。%Through the analysis and determination of pasting property, dynamic and static rheological properties of corn starch and guar gum mixed system with or without sodium chloride and calcium chloride, the effects of sodium chloride and calcium chloride on corn starch and guar gum mixed system were studied. The results showed, the addition of sodium chloride and calcium chloride increased the pasting temperature of corn starch and guar gum mixed system, decreased the breakdown value and consistence value, and the peak viscosity also dropped slightly. The G′ value of elastic modulus decreased significantly, the frequency dependence of G" value of viscous modulus was larger. The addition of sodium chloride and calcium chloride enhanced pseudo-plasticity of corn starch and guar gum mixed system, and calcium chloride was more effective.

  10. Determination of the molar substitution degree and substitution position of hydropropyl guar gum%羟丙基瓜尔胶中羟丙基摩尔取代度以及取代位置的表征

    Institute of Scientific and Technical Information of China (English)

    张明华; 彭树华; 何建平; 王军民; 巩沛鑫; 王克

    2009-01-01

    本文探索了表征羟丙基瓜尔胶(HPG)中羟丙基摩尔取代度(MS)以及取代位置的化学方法.当反应温度为110℃、反应时间为14h以及HPG中羟基与对甲苯磺酸-乙酸酐摩尔比为1:3.5时,用对甲苯磺酸-乙酸酐化学法和气相色谱法可准确测定HPG的羟丙基MS,与1H-NMR测定结果相对误差小于10%.在pH=10.30和0℃的条件下,瓜尔胶的伯羟基被2,2,6,6-四甲基哌啶氮--氧化物(TEMPO)-NaClO-NaBr体系选择性氧化成羧基,由此可表征羟丙基链段的取代位置.%An improved chemical method for the determination of the molar substitution degree and substitution position of hydropropyl guar gum has been described.The hydropropyl groups are totally cleaved from modified guar gum at 110℃ in the presence of excess mixed p-toluenesulfonic-acetic anhydride for 14 hours,and the products entirely hydrolyzed into 1,2-dihyroxypropane at pH=11 in an hour.Quantifying the mass of the reaction products derived from the hyropropyl groups,the molar substitution degree of the substituted-hydropropyl guar gum can be exactly estimated,and the relative error of the method is less than 10% compared with the result of the 1H-NMR.Only primary hydroxyl groups can be oxidized to carboxyl groups by use of TEMPO-mediated oxidation,and that is applied for characterizing the substitution position of hydropropyl guar gum.

  11. 大豆分离蛋白-瓜尔胶生物材料混合体系疏水性的研究%Study on hydrophobicity of biomaterial mixture from soy protein isolate-guar gum system

    Institute of Scientific and Technical Information of China (English)

    隋春霞; 江连洲; 于国萍

    2011-01-01

    The changes of surface hydrophobicity of biomaterial mixture from soy protein isolate-guar gum under the different pH,protein,salt and guar gum concentrations was studied.The results showed:when guar gum was added into one-component soy protein isolate system, surface hydrophobicity value decreased.Soluble protein surface hydrophobicity value was the highest at pH lever of 8.0 without salt.If salt was added at pH lever of 10.0,the value was higher than that under the condition of pure water,the surface hydrophobicity value increased as salt concentration increased if salt concentration was below 0.1mol/L and at pH lever of 10.0.On the contrary,the value decreased as salt concentration increased.This study laid a theoretical foundation for film-forming mechanism of biomaterial mixture from soy protein isolate-guar gum.%以大豆分离蛋白为原料,添加瓜尔胶多糖,通过共混改性制备生物材料溶液,探讨了混合体系在不同pH、不同蛋白、盐和瓜尔胶浓度条件下表面疏水值的变化.结果表明:瓜尔胶多糖加入到单组分大豆分离蛋白体系后,会使体系表面疏水值降低;未加盐时pH=8.0条件下,体系可溶性蛋白的表面疏水值最大,加入盐后pH=10.0时混合体系表面疏水值明显大于纯水条件;且pH=10.0条件下,当盐浓度小于0.1moL/L时,体系表面疏水值随盐浓度的增大而增大,反之减小.此研究为大豆分离蛋白-瓜尔胶生物材料的成膜机理解释奠定了理论基础.

  12. Application of Guar Gum and Its Derivatives in Papermaking Reconstituted Tobacco Sheet%瓜尔胶及其衍生物在造纸法再造烟叶中的应用

    Institute of Scientific and Technical Information of China (English)

    陈冬海; 李友明; 夏正林; 万小芳; 陈威; 陈伟明

    2012-01-01

    Fiber morphology and screening situation were observed and analysed in this paper. Retention and drain- age performance of adding guar gum and its derivatives on reconstituted-tobacco slurry was researched and a conclu- sion that guar gum and its derivatives improve the retention and drainage performance of the slurry was got. We also analysed the effect of guar gum and its derivatives on physical properties of papermaking reconstituted-tobacco sheet and found that guar gum and its derivatives could improve the sheet' s tensile strength and bulk.%本文在分析了造纸法再造烟叶浆料的纤维形态及筛分情况的基础上,研究了瓜尔胶及其衍生物对造纸法再造烟叶浆料的助留助滤性能。结果表明瓜尔胶及其衍生物能够改善浆料的助留助滤性能,实验室自制的阳离子羟丙基瓜尔胶的助留助滤性能较好,当其用量为0.08%时,浆料中总细小组分首程留着率较未添加时提高了44.0%,浆料的打浆度由43°SR下降到21°SR。同时研究了瓜尔胶及其衍生物对造纸法再造烟叶基片物理性能的影响,结果表明在添加量适当时,阳离子羟丙基瓜尔胶和阳离子瓜尔胶一丙烯酰胺接枝共聚物能够在不影响基片匀度的情况下提高基片的抗张强度和松厚度。

  13. EFFECT OF LUMINAL pH CHANGES ON GUAR GUM-HPMC E15 LV MIXED MATRIX TABLETS FOR MESALAMINE DRUG DELIVERY TO COLON AND STUDY ON IN- VITRO CHARACTERISTICS IN TWO DIFFERENT DISSOLUTION MODELS vs. MARKETED FORMULATION

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    A. Maria John Newton*, L. Prabakaran and K.N. Jayaveera

    2012-07-01

    Full Text Available The study was designed to investigate the impact of colonic pH changes on formulated colon targeted Mesalamine matrix tablets in the treatment of inflammatory bowel disease (IBD. Mesalamine tablets were fabricated with guar gum as Polymer system. The different batches of Mesalamine tablets (GMM1-GMM6 were compressed with increasing proportion of guar gum and HPMC E15 LV. The different buffer conditions were chosen to mimic the pH changes in terminal part of the ileum as well as the colon. A separate two in vitro studies were conducted in all the formulations. The impact of the pH changes on the coated tablets in normal pH condition and reduced pH condition (pH reduced during IBD were compared. In IBD the pH of the colon falls below its normal level. The extent of pH change depends on the severity of the disease. The study was designed to evaluate the in vitro dissolution characteristics of Mesalamine matrix tablets in a variety of simulated fluids (pH range 1.2, 6, 6.8, 7.2, 5. The results indicated that the impact of pH changes on drug release profile was not affected in the diseased and normal pH condition of the colon. The present treatment methods of IBD mostly depend on pH sensitivity polymers or enteric coating technique. These pH sensitive polymers based colonic devices may not serve the patient needs successfully because the influence of colonic pH on pH sensitive polymer based devices plays an important role in triggering the drug release in target site. The lowered pH condition in diseased state could not trigger the drug release in pH sensitive polymer based devices as it was not the threshold pH of the particular coated polymer. In case of enteric coating there may be a possibility of disintegration of the tablet before reaching the colon due to the contractile movement of GI tract and fluctuation in the GI pH. The present matrix tablets were prepared with guar gum, which cannot be affected by the pH changes of the colon, maintained

  14. Partially hydrolyzed guar gum in the treatment of irritable bowel syndrome with constipation: Effects of gender, age, and body mass index

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    Luigi Russo

    2015-01-01

    Full Text Available Background/Aims: Partially hydrolyzed guar gum (PHGG relieves symptoms in constipation-predominant irritable bowel syndrome (IBS and may have prebiotic properties. However, the correlation between the effectiveness of PHGG and patient characteristics has not been examined. We aimed to investigate the effect of PHGG in symptom relief on constipation-predominant IBS according to gender, age, and body mass index (BMI. Patients and Methods: Sixty-eight patients with IBS entered a 2-week run-in period, followed by a 4-week study period with PHGG. Patients completed a daily questionnaire to assess the presence of abdominal pain/discomfort, swelling, and the sensation of incomplete evacuation. The number of evacuations/day, the daily need for laxatives/enemas and stool consistency-form were also evaluated. All patients also underwent a colonic transit time (CTT evaluation. Results: PHGG administration was associated with a significant improvement in symptom scores, use of laxatives/enemas, stool form/consistency and CTT. At the end of the study period and compared with baseline, the number of evacuations improved in women, patients aged ≥ 45 years and those with BMI ≥ 25 (P < 0.05 for all comparisons; abdominal bloating improved in males (P < 0.05, patients < 45 years (P < 0.01 and those with BMI < 25 (P < 0.05. A decrease in the number of perceived incomplete evacuations/day was reported in patients with a BMI ≥ 25 (P < 0.05. Reductions in laxative/enema use were recorded in females (P < 0.05, patients < 45 years (P < 0.01, and patients with BMI < 25 (P < 0.05. Conclusions: Gender, age, and BMI seem to influence the effect of PHGG supplementation in constipated IBS patients. Further studies are needed to clarify the interaction of such parameters with a fiber-enriched diet.

  15. Effects of Dietary Inclusion of Guar Meal Supplemented by β-Mannanase on Performance of Laying Hens, Egg Quality Characteristics and Diacritical Counts of White Blood Cells

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    Mohammad Ehsani

    2010-01-01

    Full Text Available Problem statement: Using Guar Meal (GM in poultry diets has being limited because of having β-mannan, one of the Nonstarch Polysaccharides (NSP. In this study we try evaluating effects of enzyme supplementation of GM-included diets on productive performance of laying hens. Approach: A total number of 144 Lohmann LSL-Lite hens were divided in 24 cages (n = 6. Based on a 3 × 2 factorial arrangement of treatments, six iso-caloric and iso-nitrogenous diets including 3 levels of GM (0.0, 35.0 and 70.0 g kg-1 with and without enzyme (Hemicell® a β-mannanase-based enzyme, 0.0 and 0.6 g kg-1 were assigned to hens in 4 cages (replicates. Data was analyzed based on completely randomized design using GLM procedure of SAS. Results: Dietary GM inclusion significantly affected on Egg Production (EP on weeks 2, 4 and 6 as well as the overall trail period. Hens fed the GM-included diets did have decreased EP compared to hens fed the control diet. Almost the same trend was observed in terms of Egg Mass (EM; so that hens fed the GM-included diets showed decreased EM compared to the hens fed the control diet. Enzyme supplementation did not have significant effect on EP in the present experiment, but EM was significantly improved in the hens fed the β-mannanase-supplemented diets on weeks 3, 6 and the overall experimental period. Dietary inclusion GM increased Feed Conversion Ratio (FCR of laying hens compared to the hens fed the control diets on weeks 2, 4, 6 and overall trial period. Conclusion/Recommendations: Including GM in laying hens’ diets more than 3% may decrease productive performance. Supplementing cornsoybean or corn-soybean-GM diets by β-mannanase would have beneficial effects on performance of hens especially in terms of FCR and EP.

  16. Fermentation Profiles of Wheat Dextrin, Inulin and Partially Hydrolyzed Guar Gum Using an in Vitro Digestion Pretreatment and in Vitro Batch Fermentation System Model

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    Joanne Slavin

    2013-05-01

    Full Text Available This study investigated the fermentation and microbiota profiles of three fibers, wheat dextrin (WD, partially hydrolyzed guar gum (PHGG, and inulin, since little is known about the effects of WD and PHGG on gut microbiota. A treatment of salivary amylase, pepsin, and pancreatin was used to better physiologic digestion. Fibers (0.5 g were fermented in triplicate including a control group without fiber for 0, 4, 8, 12, and 24 h. Analysis of pH, gas volume, hydrogen and methane gases, and short chain fatty acid (SCFA concentrations were completed at each time point. Quantitative polymerase chain reaction (qPCR was used to measure Bifidobacteria and Lactobacillus CFUs at 24 h. WD produced the least gas during fermentation at 8, 12, and 24 h (P < 0.0001, while inulin produced the most by 8 h (P < 0.0001. Each fiber reached its lowest pH value at different time points with inulin at 8 h (mean ± SE (5.94 ± 0.03, PHGG at 12 h (5.98 ± 0.01, and WD at 24 h (6.17 ± 0.03. All fibers had higher total SCFA concentrations compared to the negative control (P < 0.05 at 24 h. At 24 h, inulin produced significantly (P = 0.0016 more butyrate than WD with PHGG being similar to both. An exploratory microbial analysis (log10 CFU/µL showed WD had CFU for Bifidobacteria (6.12 and Lactobacillus (7.15 compared with the control (4.92 and 6.35, respectively. Rate of gas production is influenced by fiber source and may affect tolerance in vivo. Exploratory microbiota data hint at high levels of Bifidobacteria for WD, but require more robust investigation to corroborate these findings.

  17. Effect of addition of different hydrocolloids on pasting, thermal, and rheological properties of cassava starch Efeito da adição de diferentes hidrocoloides sobre as propriedades de pasta, térmicas e reológicas do amido de mandioca

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    Tatiana Dias Leite

    2012-09-01

    Full Text Available Starches and gums are hydrocolloids frequently used in food systems to provide proper texture, moisture, and water mobility. Starch-gum interaction in food systems can change the starch granule swelling and its gelatinization and rheological properties. In this study, the effect of the addition of xanthan gum (XG, sodium carboxymethyl cellulose (SCMC, and carrageenan (CAR at the concentrations of the 0.15, 0.25, 0.35 and 0.45% (w/v on the pasting, thermal, and rheological properties of cassava starch was studied. The swelling power (SP and the scanning electron microscopy (SEM of the starch gels were also evaluated. The results obtained showed that xanthan gum (XG had a strong interaction with the cassava starch penetrating between starch granules causing increase in pasting viscosities, SP, storage and loss (G', and G", respectively modulus and reduction in the setback of the starch; sodium carboxymethyl cellulose (SCMC greatly increased the pasting viscosities, the SP, and the storage and loss (G', and G", respectively modulus of the starch-mixtures, mainly due to its greater capacity to hold water and not due to the interaction with cassava starch. Carrageenan (CAR did not change any of the starch properties since there was no interaction between this gum and cassava starch at the concentrations used.Amidos e gomas são hidrocoloides frequentemente usados em sistemas alimentícios com a finalidade de fornecer textura, umidade e mobilidade de água. A interação amido-goma em sistemas alimentícios pode alterar o inchamento do grânulo de amido e as suas propriedades de gelatinização e reológicas. Neste trabalho, o efeito da adição de goma xantana (GX, carboximetilcelulose sódica (CMC e carragena (CAR nas concentrações de 0,15, 0,25, 0,35 e 0,45% (p/v sobre as propriedades de pasta, térmicas e reológicas do amido de mandioca foi estudado. O Poder de inchamento (PI e a Microscopia Eletrônica de Varredura (MEV dos géis de amido tamb

  18. Impact of the N content of Cationic Guar Gum (CGG) on the Combing of Shampoo%阳离子瓜尔胶含氮量对洗发水梳理性的影响

    Institute of Scientific and Technical Information of China (English)

    戴晓琳; 曹光群

    2012-01-01

    In this paper, the impact of the N content of shampoo conditioner guar 3-chloro-2- (hydroxypropyl) trimethylam- monium on the combing of shampoo was studied. Kjeldahl apparatus was used to measure the N content of CGG from different companies. A series of shampoo with these different CGG products were made. Research shows that the cationic guar gum with higher N content results in better combing in shampoo.%研究了洗发水中调理剂瓜尔胶羟丙基三甲基氯化铵的含氮量对洗发水梳理性的影响.利用凯氏定氮仪测定不同公司7种阳离子瓜尔胶产品中的氮含量,并将各个公司产品应用到二合一香波洗发水中进行梳理性的对比.研究表明,瓜尔胶羟丙基三甲基氯化铵的含氮量较大者应用于洗发水中梳理性较好.

  19. 低质量分数胍胶压裂液体系研究及应用%Study and Application of Low Mass Fraction Guar Gum Fracturing Fluid System

    Institute of Scientific and Technical Information of China (English)

    栾飞; 武玉东; 梁洁; 熊欣; 邢争强

    2015-01-01

    The low mass fraction guar gum fracturing fluid system adapting to the temperature of 90 ~ 130 ℃ was prepared through reducing proportion of guar gum by 10% and 2 varieties of additives. The temperature resistance, shear resistance, proppant carrying capacity and gel breaking performance of the fracturing fluid system were assessed, and the situation of field application was analyzed.%通过减少胍胶比例和添加剂种类的方法,形成了适应90~130℃的低质量分数胍胶压裂液体系,胍胶的用量整体降低了10%,添加剂的种类也减少了两种。对该压裂液体系的抗高温、抗剪切、携砂性能和破胶性能进行评价,还对其现场应情况进行了分析。

  20. Preparation and the properties of the composite films from cassava starch and guar gum%木薯淀粉-瓜尔胶复合膜的制备及性质研究

    Institute of Scientific and Technical Information of China (English)

    贾英

    2012-01-01

    The raw guar gum,anionic guar gum with cassava starch were blended to make composite basic edible film in the certain proportion.The films with different contents of starch and guar gum were respectively prepared and characterized.Their properties were measured.The film containing cassave starch and guar gum with the ratio of 80∶20 exhibited the good elongation(E).Compared with the pure starch film,tensile strength(TE)increased by 50%,E decreased by 30%,and the water vapor permeability decreased to 15.8%,water absorption changed a little.The film containing cassave starch and anionic guar gum with the ratio of 80∶20 had the good E.Compared with cassava starch film,the E increased by 142%,but the TE decreased by 22%.The water vapor permeability decreased by 5.4%,while the water absorption decreased by 5.5%.%研究木薯淀粉与瓜尔胶、木薯淀粉与阴离子瓜尔胶的复合膜,淀粉含量为复合基质量的100%、80%、60%、40%和20%制成复合膜,对膜的性质用红外、热重以及扫描电镜分别表征,对膜的力学性能、水蒸气透过率和吸水性能测试。分别以强度和伸长率为指标得出最优的复合膜配比。以强度为指标的最优复合膜成分:淀粉为80%,瓜尔胶为20%,得到样本1-2与原淀粉膜相比强度提高50%,伸长率下降30%,水蒸气透过率下降15.8%,吸水率几乎没有变化。以伸长率为指标的最优膜成分:淀粉80%,阴离子瓜尔胶20%,得到样本2-1与原木薯淀粉膜相比伸长率提高了142%,但强度降低了22%,水蒸气透过率下降了5.4%,吸水性降低了5.5%。成膜条件为:淀粉糊化温度为95℃,反应时间0.5 h,烘干温度为50℃。

  1. Oral manifestations of syphilis Manifestações orais da sífilis

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    Jair Carneiro Leão

    2006-04-01

    Full Text Available The past decade has shown a significant rise in the prevalence of infective syphilis in the developed world, and striking increases in its frequency have occurred in Eastern Europe, particularly the UK, and in the US. Although oral manifestations of syphilis are most likely to be observed during secondary disease, all stages of the disease can give rise to oral lesions. Significant oral lesions such as gumma-associated bony destruction and a possible predisposition to oral squamous cell carcinoma are associated with tertiary disease. Since the prevalence of infective syphilis in heterosexuals has been increasing, there has now been a gradual rise in the number of children born with congenital syphilis. Consequently, the congenital disease gives rise to dental anomalies as well as bone, skin, and neurological anomalies of the face. The aim of this report is to review syphilis-related oral lesions, as well as to summarize the relations between human immunodeficiency virus (HIV and syphilis.A última década tem mostrado um aumento importante na prevalência de sífilis infecciosa nos países desenvolvidos e epidemias surgiram na Europa ocidental, particularmente no Reino Unido, bem como nos EUA. Embora as manifestações orais da sífilis sejam mais freqüentes na fase secundária da doença, todos os estágios podem apresentar lesões orais. A fase terciária da doença está associada a lesões orais significativas tais como destruição óssea associada à goma sifilítica e uma possível predisposição ao carcinoma espinocelular. Com o aumento da prevalência da sífilis infecciosa, há também um aumento gradual de crianças nascidas com sífilis congênita. Consequentemente esta patologia leva a anomalias faciais de ordem dentária, óssea, dermatológica e neurológica. O objetivo deste artigo é revisar as lesões orais associadas á sífilis, bem como discorrer brevemente sobre a relação entre a infecção pelo vírus da imunodefici

  2. Pedological Heterogeneity of Soils Developed from Lithologies of the Pirambóia, Sanga-do-Cabral, and Guará Geological Formations in Southern Brazil

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    Pablo Grahl dos Santos

    Full Text Available ABSTRACT The source material is one of the factors that most influence soil genesis and the mainly responsible for the nature, composition, and behavior of the soil. Given the geological complexity of the Santa Maria River basin, the objective of this study was to investigate whether the new lithologies described recently may be responsible for a greater variation in soil properties, as well as in the soil taxonomy itself. The study area is located in the municipality of Rosário do Sul, RS, Brazil at 30° 15’ 28” S and 54° 54’ 50” W, with average altitude of 132 m and climate type Cfa. This study was supported by a cartographic base composed of topographic charts, geological maps, satellite images, digital elevation models, and maps of geomorphometric variables, with the support of GPS receivers and GIS. Topolithosequences were defined from soils developed from the Pirambóia, Sanga-do-Cabral, and Guará Formations, and soil profiles were chosen based on types of source materials, variations in relief, and altitude. A classical model of slope compartmentalization was applied for correlation of the geomorphic surfaces with pedogenesis. Soil profiles were described in a general and morphological manner, and soil samples were collected for analysis. The physical and chemical properties determined were particle size, active and potential acidity, organic C content, Ca2+, Mg2+, K+, and Al3+. The sum of bases, CEC, flocculation activity and degree of flocculation of the clay fraction, and base (V, aluminum (m, and sodium saturation were calculated. Soil properties were evaluated through factor analysis and grouping, which allowed profiles to be grouped based on their variables and identification of which variables were preponderant in distinguishing them. Furthermore, multivariate analysis allowed statistical differentiation of the profiles in the same lithostratigraphic unit and in different relief positions, and also differentiation of

  3. Potencial tecnológico do galactomanano de sementes de faveiro (Dimorphandra mollis para uso na indústria de alimentos Seeds of faveiro (Dimorphandra mollis as a potential source of galactomannan for the food industry

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    Valéria Regina PANEGASSI

    2000-12-01

    Full Text Available A utilização de gomas de sementes tem trazido muitos benefícios à indústria de alimentos, melhorando as propriedades dos produtos, principalmente pelo seu poder espessante, estabilizante e geleificante. Gomas obtidas a partir do endosperma de sementes de leguminosas são compostas por manose e galactose (galactomanano. A partir da trituração e posterior peneiramento das sementes de faveiro (Dimorphandra mollis, espécie brasileira que ocorre com alta freqüência nos cerrados e caatinga, foi obtido um extrato rico em galactomanano (83,2% com proporção manose:galactose 2,7. Esses parâmetros são comparáveis aos obtidos para os galactomananos de uso consagrado em formulações de alimentos, tais como a goma guar com 78-82% de rendimento e razão manose galactose igual a 2 e a goma locusta com 88% de rendimento e razão manose:galactose igual a 4. Ensaios biológicos demonstraram que a goma do faveiro é considerada praticamente atóxica. Esses resultados sugerem que a goma de Dimorphandra mollis apresenta potencial para ser utilizada em formulações de alimentos. Além disso, como é espécie já utilizada para a extração de rutina e também espécie de larga ocorrência em ecossistemas de grande importância tais como o Cerrado e a Caatinga, sua exploração poderia ser feita de forma ecologicamente sustentável.The use of seed gums has brought a lot of benefits to the food industry, improving their properties primarily for their ability of thickening, stabilising and gelling. The gums obtained from the endosperm of legume seeds are composed of mannose and galactose in different proportions. Using a procedure of grinding and milling, an extract rich in galactomannan (83.2%, with a mannose:galactose ratio of 2.7, was obtained from faveiro (Dimorphandra mollis, which is a Brazilian species native to the savannah and caatinga environments. The yield and composition obtained were comparable to the commercially exploited gums of guar

  4. Pancreatite esclero-gomosa simulando sindrome cancerosa da cabeça do pâncreas

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    A. Penna de Azevedo

    1944-06-01

    Full Text Available Em um homem de 49 anos de idade, observou-se um sindrome de tumor da cabeça do pâncreas. Realizada a intervenççao cirúrgica foi verificada a presença de uma formaão dura de aspecto fibroso, medindo 9 x 7,5 x 6,5 cm. O exame microscópico mostrou tratar-se de uma pancreatite indurativa associada à presença de gomas miliares, infiltração de eosinófilos e lesões produtivas dos vasos sanguíneos, correspondendo ao aspecto dos processo esclerogomosos sifilíticos do pâncreas.A tumor of the head of the pancreas is reported ina a male, 49 years old, which corresponded to a nodule of fibrous tissue measuring 9 x 7,5 x 6,5 cm. Microscopically, a chronic interstitial pancreatitis associated to miliary gummata, eosinophilic infiltration and proliferation of blood vessels was found and the diagnosis of siphilitic pancreatitis was done.

  5. ESTUDIO PRELIMINAR SOBRE LA INFLUENCIA DE LA CARRAGENINA KAPPA, KAPPA I.II Y GOMA TARA EN LA VISCOSIDAD Y TIXOTROPÍA DE LAS SALMUERAS DE INYECCIÓN PARA JAMONES COCIDOS PICADOS DE CERDO PRELIMINARY STUDY ON THE INFLUENCE OF KAPPA, KAPPA I.II CARRAGEENAN AND TARA GUM IN THE VISCOSITY AND THIXOTROPY OF INJECTION BRINES FOR COOKED CHOPPED HAMS OF PORK

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    Fabio Alexander Molina Cote

    2010-12-01

    Full Text Available El presente estudio determinó el efecto que sobre la viscosidad y la tixotropía de una salmuera de masajeo para jamones picados cocidos de cerdo, tiene la adición de carragenina kappa, carragenina kappa I.II y goma tara, cuando son usadas a un nivel del 1% en la salmuera. Para tal efecto se incorporaron seis mezclas distintas de hidrocoloides provenientes de la carragenina kappa, kappa I.II y goma tara (individualmente, en mezclas binarias y mezclas terciarias, en una salmuera de inyección y masajeo para jamones; a las cuales se les determinó su comportamiento viscoso y tixotrópico a 4 ºC. Los datos obtenidos de índice de tixotropía (máximos, se analizaron mediante un modelo cuadrático derivado de un arreglo de mezclas. Los resultados mostraron que todas las salmueras se comportaron tixotrópicamente, presentando mayor área de histéresis, las mezclas que contenían goma tara. El modelo usado para el índice de tixotropía arrojó, con un nivel de significancia de 0,05, que la relación óptima, es la que contiene la mezcla de carragenina kappa I.II-goma tara (79% y 21%. Adicionalmente, las salmueras que contenían carragenina kappa, carragenina kappa I.II y carragenina kappa-carragenina kappa I.II presentaron menor viscosidad que las mezclas que contenían goma tara.The aim of this study was to determine the thixotropy´s effect of a massage brine in cooked chopped pork hams with addition of kappa, kappa I.II carrageenan, tara gum and their mixtures, when were used at 1% injection level of brine to meat. Six mixtures were evaluated. A protocol for thixotropy measurement adjusted to the conditions of brines used taking in account salinity, pH, temperature and shear stress. Data obtained from thixotropy index (maximum were analyzed with quadratic model derived from blends array. Results showed thixotropic measurement to brines presented a very small area, showing structural changes, but with very fast recovery. It was observed

  6. Caracterização morfofisiológica e análise de PCR-SSCP de isolados de Phytophthora da acácia-negra na região Sul do Brasil

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    Tatiane Cristina Albuquerque Alves

    2011-09-01

    Full Text Available O objetivo do trabalho foi caracterizar isolados de Phytophthora da acácia-negra (Acacia mearnsii provenientes do Sul do Brasil, com base em características fenotípicas tais como morfologia, crescimento micelial, características das culturas, compatibilidade sexual e patogenicidade, e em perfis de polimorfismo de conformação de fita simples (SSCP = Single Strand Conformation Polymorphism da região ITS-gene 5.8S do rDNA. Os isolados apresentaram esporângios com papilas proeminentes, arranjo dos esporângios irregularmente simpodial, culturas heterotálicas com presença de anterídios anfígenos, presença de clamidósporos e crescimento micelial em temperatura acima de 35°C, permitindo a classificação dos 12 isolados como P. nicotianae. Todos os isolados foram patogênicos, causando necrose em ramos de acácia-negra, sem formação de goma, com diferenças significativas de agressividade (p=0,05. Duas populações podem ser distinguidas em P. nicotianae da acácia negra pela análise PCR-SSCP do rDNA; no entanto essa separação não apresenta aparente correlação com características fenotípicas.

  7. Avaliação da incorporação de galactomanana de Caesalpinia pulcherrima em sorvetes e comparação com estabilizantes comerciais

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    Antonia Ariana Camelo Passos

    2016-06-01

    Full Text Available RESUMO Com o mercado cada vez mais competitivo e consumidores mais exigentes é de suma importância buscar alternativas mais eficientes e diversificadas para a melhoria da qualidade de sorvetes. Este trabalho teve como objetivo desenvolver sorvetes sabor goiaba utilizando galactomanana de Caesalpinia pulcherrima em substituição a estabilizantes, avaliar suas propriedades e comparar com dois estabilizantes comumente utilizados (goma xantana e super liga neutra. Para caracterizar os sorvetes foram feitas análises de overrun, resistência ao derretimento, umidade, cinzas, proteínas, lipídios, carboidratos, sólidos totais e pH. A qualidade microbiológica foi investigada pelas análises de coliformes a 45 °C/g, Estafilococos coagulase positiva/g e Salmonella sp/25 g. Sensorialmente, foram avaliados a intenção de compra e os atributos sensoriais de cor, aroma, textura, sabor e impressão global. Foram realizadas três formulações de sorvetes, modificando o estabilizante empregado: super liga neutra (T1, galactomanana de C. pulcherrima (T2 e goma xantana (T3. A taxa de derretimento mostrou-se similar até 35 minutos para as três formulações, mostrando-se comportamentos lineares. As amostras de sorvetes apresentaram um bom valor de overrun. Nenhuma das variáveis físico-químicas apresentou diferença estatística entre si. Sensorialmente, a formulação T2 apresentou desempenho semelhante a T1 e T3. No entanto, o sorvete da formulação T3 apresentou no atributo textura uma nota melhor que o estabilizante super liga neutra (T1. Todas as formulações apresentaram altos índices de intenção de compra por parte dos provadores. Todos os sorvetes produzidos apresentaram-se de acordo com a legislação vigente demonstrando que a galactomanana de Caesalpinia pulcherrima pode ser utilizada como substituto aos estabilizantes convencionais.

  8. 有机锆对羧甲基羟丙基瓜胶的交联性能研究%Study on the crosslinking properties of the organic zirconium/carboxymethyl hydroxypropyl guar gum*

    Institute of Scientific and Technical Information of China (English)

    刘祥; 李丛妮

    2011-01-01

    The zirconium-organic crosslinker, which can be used for carboxymethyl hydroxypropyl gnat gum in acidic condition, was synthesized using zirconium oxychloride and citric acid as raw material. The effects of pH value, temperature, cross-linking agent and carboxymethyl hydroxypropyl guar gum amount on crosslinking time have been discussed. The gel prepared under zirconium-organic crosslinker, whose stability of temperature resistance and shear, filtration properties and gel breaking performance on gel formation has been evaluated. When pH value was 3.0, the results showed that carboxy- methyl hydroxypropyl guar gum/organic zirconium system has a property of controllable delay crosslinking properties, and with the mass fraction of carboxymethyl hydroxypropyl guar gum is 0.5% and 0.6%and the crosslinking rate 100:1.6 to 100:2.0, the gel prepared showed good shear stability and low filtration. Moreover, the gel broke completely and had a low residue.%以氧氯化锆和柠檬酸等为原料,合成了适用于羧甲基羟丙基瓜胶在酸性条件下交联的有机锆交联剂,考察了pH值、温度、羧甲基羟丙基瓜胶和交联剂加量等对体系成胶时间的影响,评价了形成冻胶的抗温抗剪切性能、滤失性能和破胶性能.实验发现,在pH值为3.0时,羧甲基羟丙基瓜胶/有机锆体系具有可控的延缓交联特性,质量分数为0.5%和0.6%的羧甲基羟丙基瓜胶在交联比为100:1.6~2时形成的冻胶具有较好的剪切稳定性,较低的滤失量,且破胶彻底,残渣含量低.

  9. Synthesis of Graft Copolymer of Acryl Amide onto Guar Gum by Inverse Emulsion%瓜尔胶/丙烯酰胺的反相乳液接枝共聚

    Institute of Scientific and Technical Information of China (English)

    林兆云; 张贤贤; 李友明; 万小芳; 刘军

    2012-01-01

    A graft copolymer of guar gum with acryl amide was made by using ammonium eerie nitrate/ nitric acid as initiator. The effects of m ( AM): m ( GG), initiator concentration, reaction temperature and reaction time on polymerization were investigated. The results indicate that the grafting ratio and comonomer conversion of grafting copolymerization were 147. 05% and 87.7% when m{ AM} :m( GG) = 3:2,initiator concentration was 4 mmol/L,reaction time was 4 h and reaction temperature was 45 ℃. The largest molecule of the graft copolymer could reach a dimension of 1. 73 × 106. The analysis of IR spectrum shows that AM was substantially grafted onto the molecular chain of guar gum. TGA indicates that the grafted AM has no effect on the thermal stability of guar gum.%以硝酸铈铵/硝酸为引发剂,在反相乳液中引发瓜尔胶/丙烯酰胺的接枝共聚反应.考察了m(丙烯酰胺AM)∶m(瓜尔胶GG)、引发剂浓度、反应温度和反应时间对接枝聚合的影响.结果表明,当m(AM)∶m(GG)=3∶2,引发剂浓度为4mmol/L,反应时间为4h,反应温度为45℃时,接枝共聚反应的接枝率和单体转化率分别为147.05%和87.7%.接枝共聚物的最大相对分子质量(简称分子量,下同)可达到1.73×106.红外光谱(IR)分析证明了AM确实接枝到GG分子链上,热重分析(TGA)显示接枝的AM单体并未影响GG的热稳定性.

  10. Research and application of guar gum solution mixing equipment in food industry%食品工业中瓜尔胶溶液配制设备的研究与应用

    Institute of Scientific and Technical Information of China (English)

    罗彤彤

    2011-01-01

    为解决食品工业瓜尔胶溶液的配制问题,本文开展了影响溶液配制因素的研究,考察搅拌时间、静止时间、温度对溶液配制的影响;研制了专利溶液配制设备,采用集成化设计、模块化配置和自动化控制.主体设备包括高效混合器、静态分散器、快速释放机;辅助设备有多级上料装置、精密给料装置等;以及自动控制系统.该设备特点是溶液浓度准确,水粉高效混合,粘度快速释放,瞬间达到最佳分散状态,不产生水包粉现象.胶粉用量在0.2%~1.0%之间连续可调,粘度波动范围小,自动配液粘度波动±1%,手动配液粘度波动±2%.配液设备出口粘度达到标称粘度80%以上,静止10min即达到标称粘度.%The research is carried out on the influencial factors of guar gum solution mixing, such as agitating time,static time and temperature. Efficient - mixing and rapid - releasing equipment has been developed, adopting integration design, modularized allocation, automatic control. Main parts consist of efficient mixing set, static dispersing set,rapid releasing set; auxiliary parts consist of multistage feeding set, precision feeding set and automatic control system.The chief characteristics are as follows, solution concentrate is correct, guar gum and water mix efficiently without lump, solution viscosity increases rapidly, guar gum dosage is adjustable between 0.2%~ 1.0% successively, viscosity has a small fluctuation, auto mode 1%, manual mode 2%. Solution viscosity at equipment outlet is 80% of nominal viscosity, achieving nominal viscosity after 10min releasing.

  11. Effect of magnesium chloride guar gum mixture on the coagulation process of tofu%氯化镁瓜尔胶复合凝固剂对豆腐凝固过程影响

    Institute of Scientific and Technical Information of China (English)

    李蒙; 陈复生; 杨宏顺; 王萌蕾; 赖少娟

    2014-01-01

    分别利用氯化镁、石膏和氯化镁、瓜尔胶复配凝固剂制作豆腐,瓜尔胶降低了氯化镁制作豆腐的硬度,但复配凝固剂制作的豆腐和石膏豆腐有相似的质构特性,红外光谱对三种豆腐粉末测定的结果表明:三种凝固剂对豆腐中蛋白的二级结构并没有影响;在37℃下研究三种凝固剂对豆浆黏度变化的影响,发现瓜尔胶提高了凝固过程第一阶段的速率,但降低了第二阶段凝固过程的速率。瓜尔胶通过改变豆浆的凝固速率影响了豆腐的凝胶结构和质构特性。%Magnesium chloride based coagulants were compared with traditional gypsum for coagulating tofu. The hardness of magnesium chloride coagulated tofu decreased significantly after adding guar gum,being much closer to gypsum coagulated tofu. The texture profile of tofu coagulated by the mixture coagulant was similar as tofu prepared with gypsum. The results of FTIR shows the coagulants had little effect on the secondary structure of denatured protein during the coagulation process,viscosity results of soymilk coagulated with these three coagulants at 37℃ indicated guar gum promoted the coagulation rate in the first stage,whereas the rate decreased in the second stage. The change of coagulation rate of soymilk resulted from adding guar gum modified the network and the texture profile of the tofu prepared with MgCl2.

  12. Depressant behavior and mechanism of guar and xanthan gums on calcite flotation%瓜尔胶和黄原胶对方解石浮选的抑制行为差异及机理

    Institute of Scientific and Technical Information of China (English)

    高志勇; 宋韶博; 孙伟; 胡岳华; 钟宏

    2016-01-01

    The depressant behavior and mechanism of guar and xanthan gums on calcite flotation were investigated through flotation experiment, adsorption study,zetapotential measurement and infrared spectroscopy measurement. The results show thatwhenpHis8.8 and oleate concentrationis 0.3 mmol/L, xanthan gum with a dosage of 50mg/L can markedly reduce the adsorption capacity of sodium oleate on calcite surfaces, and hence decrease the calcite recovery, while a higher dosage of 100mg/L for guar gum should be added in order to achieve the similar depressant effect.The guar gumisadsorbedon calcite surface through hydrogen bonding, while xanthan interacts with calcite through chemisorption and hydrogen bonding.%采用浮选试验、吸附量测试、zeta电位测试、红外光谱测试等方法研究瓜尔胶(非离子型)和黄原胶(阴离子型)2种天然胶对方解石的浮选抑制行为及机理。研究结果表明:当pH为8.8,油酸钠浓度为0.3 mmol/L时,用量为50 mg/L的黄原胶,可显著降低捕收剂油酸钠在方解石表面的吸附量,降低方解石的浮选回收率,而瓜尔胶要达到相同的抑制效果,用量需超过100 mg/L。上述抑制行为差异主要是由于2种天然胶在方解石表面的吸附方式和强度不同造成的。瓜尔胶通过氢键作用在方解石表面吸附,而黄原胶的主要作用方式为化学键合和氢键作用。

  13. Método de avaliação da resistência de clones de cajueiro à resinose

    Directory of Open Access Journals (Sweden)

    José Emilson Cardoso

    2010-12-01

    Full Text Available A resinose (Lasiodiplodia theobromae é uma importante doença do cajueiro no Brasil. A resistência genética é o método mais promissor de controle, entretanto, a seleção de clones resistentes em campo é onerosa e demorada. Com o objetivo de definir um método de seleção precoce de genótipos resistentes à resinose, foram avaliados meios de cultura para produção de inóculo e métodos de inoculação do patógeno. Foram avaliados os método do bisel, da injeção de suspensão de esporos e do palito nos clones BRS 226 (resistente e CCP 76 (susceptível. O efeito do estresse hídrico produzido pelo aumento do intervalo de rega (diário, três, seis e sete dias das plantas foi testado com os melhores métodos de inoculação. Aos 17 e 21 dias após a inoculação foram feitas avaliações externa e interna dos sintomas (exsudação de goma, comprimento da lesão e morte, respectivamente. O meio de aveia-ágar para produção de inóculo do fungo e os métodos do bisel e da injeção foram os mais eficientes. A avaliação externa não possibilitou diferenciar genótipos, enquanto que, pela lesão interna foi possível diferenciar as reações entre os clones, independentemente do intervalo de regas. O método do bisel foi o melhor para diferenciação dos clones.

  14. Analysis of the geometry of diabase sills of the Serra Geral magmatism, by 2D seismic interpretation, in Guareí region, São Paulo, Paraná basin, Brazil

    Directory of Open Access Journals (Sweden)

    Diego Felipe Bezerra da Costa

    Full Text Available ABSTRACT: The Paraná Basin holds in its stratigraphic record a thick layer of volcanic rocks related to the opening of the Gondwana Supercontinent, which occurred during the Eocretaceous. Based on the interpretation of three two-dimensional (2D seismic lines in the region of Guareí, East-Central São Paulo state, in the Southeast of Brazil, the subsurface geometries of these volcanic rocks were identified. Since the original seismic resolution quality was low, alternative techniques were utilized to improve the seismic imaging, such as isolating maximum and minimum amplitude values by manipulating the color scale, and using the root mean square (RMS attribute and the Amplitude Volume technique (tecVA, which emphasize the seismic signature of igneous rocks in relation to sedimentary layers. The use of such techniques allowed the identification of different geometries of diabase sills and showed a relationship between these intrusive and organic matter maturation of the source rock.

  15. 压裂用瓜胶用杀菌剂筛选与作用效果评价%Screening and Evaluation of Bactericide for Guar Gum using in Fracturing Fluid

    Institute of Scientific and Technical Information of China (English)

    薛东圆; 张洁; 秦芳玲; 汤颖; 谢璇

    2015-01-01

    油田压裂液稠化剂主要是植物胶,由于受到微生物的降解,天然植物胶极易发生降解、解黏和发霉等问题.本研究通过对4类杀菌剂及复配杀菌剂对瓜胶原液黏度保持作用的对比,评价了其杀菌效果.结果表明,0.5%的丙烯醛、0.5%脲醛、0.5% 1,4-对苯二酚、0.1%水解植物酚、0.9﹪生理盐水及0.9% NaCl与0.5%丙烯醛的复配杀菌剂具有较显著的抑制瓜胶降解的作用,在杀菌处理4d时,0.5%瓜胶原液的黏度降低率均低于16%.%Plant gum was the main viscosifier in oil field fracturing fluid. The plant gum degraded and mildewed easily, and the vis-cosity of its solution decreased correspondingly. In this work, the efficiency of the bactericides was evaluated by the viscosity main-taining. The results showed that 0.5% acrolein, 0.5% urea formaldehyde, 0.5% 1,4-hydroquinone, hydrolyzed plant phenol, 0.9% saline and 0.9% NaCl & 0.5% acrolein could inhibit the degradation of guar gum, and the viscosity of 0.5% guar gum solution only decreased by less than 16% within 4d.

  16. 瓜尔豆胶对凹凸棒石黏土胶体黏度的影响%Inlfuences of Adding Guar Gum on Viscosity of Attapulgite Colloid

    Institute of Scientific and Technical Information of China (English)

    徐金覃; 尹琳; 陆现彩

    2015-01-01

    向粉碎至150μm的凹凸棒石黏土中添加不同比例的瓜尔豆胶,然后用不同的制浆方法制备盐饱和胶体,并分别测试胶体的黏度和筛余量。结果表明:剪切能力强的搅拌机有助于凹凸棒石黏土分散成胶,提高胶体黏度降低筛余量;瓜尔豆胶能增加凹凸棒石胶体的黏度,但添加过量后会导致胶体絮凝从而降低胶体黏度;用筛余量表征添加了瓜尔胶的凹凸棒石黏土胶体的絮凝情况有一定局限性。%In order to make colloid with saturated salt water of higher viscosity, adding various amounts of guar gum into attapulgite clay with sizes less than150μm and several methods of colloid preparation were optimized in this study. The measured colloidal viscosity and its sieve remains indicate that addition of guar gum can clearly increase the viscosity of clay colloid, but excessive addition leads to viscosity decreasing and sieve remains increasing due to colloidal lfocculation. Stronger stir-force mixer can be used to improve the viscosity of attapulgite colloid and reduce colloidal sieve remains. It is also found that the parameter of sieve remains has limitation to represent viscosity and lfocculation of attapulgite colloid.

  17. 2-羟基-3-丁氧基丙基胍胶的制备及流变性能%Preparation and rheological property of 2-hydroxy-3-butoxypropyl guar gum

    Institute of Scientific and Technical Information of China (English)

    薛小佳; 沈一丁; 赖小娟; 王磊; 赵建波

    2012-01-01

    以胍胶原粉(GG)为原料,正丁基缩水甘油醚(BGE)为疏水化试剂,氢氧化钠为催化剂,异丙醇为溶剂,制备了2-羟基-3-丁氧基丙基胍胶(HBPG)。通过FT-IR、XRD、TGA对HBPG结构性能进行了表征,并研究了HBPG水溶液和冻胶的流变性能。结果表明,HBPG结构中由于引入疏水基团,使其结晶度下降,热稳定性能提高,HBPG相比GG具有更好的增稠性能,且溶液稳定性能得到明显改善,HBPG制备的冻胶的流变性能优于GG,具有良好的耐温和剪切稳定性能。%2-hydroxy-3-butoxypropyl guar gum(HBPG) was synthesized with guar gum(GG) as material,using n-butyl glycidyl ether(BGE) as the hydrophobic reagent,sodium hydroxide as catalyst and isopropanol as solvent.The structure of HBPG was characterized by means of FT-IR,XRD and TGA,meanwhile,the rheological property of the aqueous solution and the gel of HBPG were discussed.The results showed that the hydrophobic modification can reduce the crystallinity and improve the thermal stability.Compared to GG,HBPG has better thickening property and the solution stability has significantly improved.The rheological property of the gel of HBPG was better than GG.The gel of HBPG has good temperature resistance and shear stability properties.

  18. THE GEOLOGIC RISK IN THE LAKE KIVU BASIN AREA PRODUCTED BY EARTHQUAKES. Case of the February 3th 2008 earthquake. By: L.M.Bagalwa(1), F.Lukaya(1), M.Burume(2), J.Moeyerson(3) (1): Goma Volcano Observatory, D.R.Congo (2): Naturals Sciences Research Center

    Science.gov (United States)

    Bagalwa Rukeza, Montfort

    2010-05-01

    The eastern Democratic Republic of Congo is prone to earthquakes of magnitude greater than or equal to 4 on the Richter scale. The western edge of Lake Kivu, the most populated part of the region is no exception to the solicitation of these earthquakes. Since 1997, the western basin of Lake Kivu is experiencing intense seismicity, several earthquakes of great intensity, magnitude greater than or equal to 4 develop major destructive phenomena. These include the 1997 earthquake (M = 4.7) 2000 (M = 4.6 and 5.4), 2002 (M = 4.9, 5.2, 6.1 and 24 October 2002 M = 6.2) of February 3rd 2008 (M = 6). Earthquakes of Kalehe on October 24th 2002 and Birava, February 3rd 2008 have resulted deformations of soil, human and material damage. This latest natural disaster ever known in the south-western basin of Lake Kivu has attracted our scientific curiosity we go there to inquire into its causes and consequences in this region. The basin of Lake Kivu is affected by transform faults emerging (MUKONKI & CHOROWICZ, 1980, quoted by K.S.KAVOTHA & ali, 1990) that delimit the Rift were intersecting at the level of Lake Kivu. We Consider the seismicity, volcanism and uplift of the basin of Lake Kivu as a sign of fracturing under way to delimit a plate tectonics formed (Wong and Von Herzen, 1974, quoted by KSKAVOTHA et al, 1990). The physiography of Lake Kivu is dominated by the fault which borders the western shore and one which intersects the island of Idjwi. The telemetry data of Goma Volcano Observatory added to those of the seismographic station of Lwiro have always revealed a pattern of epicenters clearer in Lake Kivu. In correlation with the faults of the region, earthquakes affect mainly the western edge of Lake Kivu and the island of Idjwi with increasing density from north to south (K.S.KAVOTHA et al, 1990). The great earthquake of Lake Kivu basin on February 03rd 2008, of magnitude 6 on the Richter scale occurred at 07 hours 34 minutes 12 seconds GMT, about 20 km north of Bukavu

  19. 结肠定位释药瓜尔胶/乙基纤维素包衣小丸%Guar gum/ethylcellulose coated pellets for colon-specific drug delivery

    Institute of Scientific and Technical Information of China (English)

    季崇敏; 徐惠南; 孙宁云; 陆燕萍; 吴伟

    2007-01-01

    体外研究瓜尔胶/乙基纤维素混合包衣小丸的结肠靶向性.以5-氟尿嘧啶为模型药, 采用流化包衣技术以瓜尔胶/乙基纤维素混合物的水/醇混悬液对载药小丸进行喷液包衣.瓜尔胶/乙基纤维素混合包衣小丸的释药行为取决于包衣处方中瓜尔胶与乙基纤维素的比例和包衣厚度.分别以混合包衣液中瓜尔胶与乙基纤维素的比例及包衣增重为自变量, 以T5和T90(药物释放5%和90%所需要的时间)为效应, 进行3×4析因设计/效应面优化, 筛选较优处方.结果表明随着乙基纤维素在衣层中所占比例的增大及包衣厚度的增加, 药物释放时滞增加.当瓜尔胶与乙基纤维素的比例在0.2~0.7, 并且包衣增重在250%~500%时, T5%为5.1~7.8 h, T90%为9.8~16.3 h.并且在释药时滞之后, 进入模拟结肠微菌群酶解作用的释放环境中(pH 6.5)药物释放速度加快, T90%缩短到9.0~14.5 h.由此可以看出适当的瓜尔胶/乙基纤维素混合衣层既可以保护药物顺利通过上消化道而不释放, 达到结肠后药物开始释放, 并且可在结肠微菌群的酶解作用下加速药物的释放, 实现结肠定位释药的目的.%The aim of this work was to investigate guar gum/ethylcellulose mix coated pellets for potential colon-specific drug delivery. The coated pellets, containing 5-fluorouracil as a model drug, were prepared in a fluidized bed coater by spraying the aqueous/ethanol dispersion mixture of guar gum and ethylcellulose. The lag time of drug release and release rate were adjustable by changing the ratio of guar gum to ethylcellulose and coat weight gain. In order to find the optimal coating formulation that was able to achieve drug targeting to the colon, the effect of two independent variables (the ratio of guar gum to ethylcellulose and the coat weight gain) on drug release characteristics was studied using 3×4 factorial design and response surface methodology. Results

  20. pH值对羟丙基胍胶压裂液性能的影响%Effect of pH Value on Performance of Hydroxypropyl Guar Gum Fracturing Fluid

    Institute of Scientific and Technical Information of China (English)

    唐洪彪; 王世彬; 郭建春

    2016-01-01

    为了弄清压裂液的pH值在水力压裂施工不同阶段所起的作用,开展了pH值对羟丙基胍胶溶胀、交联、携砂、破胶性能的影响研究。结果表明,pH=7数10时,羟丙基胍胶在20 min内完全溶胀;pH=11数14时,羟丙基胍胶至少需要50 min才能完成溶胀。Ostwald-Dewaele方程能描述冻胶黏度随剪切速率变化关系,pH=7数12时的稠度系数较大,大于16744 mPa·sn;pH=13数14时的稠度系数明显减小,小于3130 mPa·sn。静态沉降实验表明,pH=9数12时的静态沉降速度较小,为1.31数5.94 mm/h;pH=7、8、13时的静态沉降速度较大,大于10.64 mm/h;pH=14时,支撑剂20 s内完成沉降。破胶实验研究发现,冻胶在pH=7数10时的破胶速度大于pH=1数14时的破胶速度;pH=7数12时,残渣含量较小,为400 mg/L左右。满足各施工阶段的pH值范围为9数10。图5表2参12 lnha=lnK+(n-1)lng%pH was an important factor affecting the performance of hydraulic fracturing. The effect of pH on the swelling performance of hydroxypropyl guar gum,crosslinking properties,proppant settlement,guar gum degradation was studied. The results showed that,at the pH value of 7—10,the swelling time of hydroxypropyl guar gum was less than 20 min,while at the pH value of 11—14 ,the swelling time was larger than 50 min ,the swelling rate at the pH value of 7—10 was relatively higher than that at the pH value of 11 —14. The relationship between gel viscosity and shear rate could be described by the Ostwald-Dewaele equation ,and at the pH value of 7—12 ,the consistency coefficient of hydroxypropyl guar gum solution was larger than 16744 mPa·sn,while the consistency coefficient at the pH value of pH 13—14 was less than 3130 mPa·sn. The proppant settlement experiments showed that,at the pH value of 9—12,the settling rate of proppant was relatively low,being of 1.31—5.94 mm/h;at the pH value of 7,8,13,the settling rate increased and the value

  1. An estimation of the frequency of gestational toxoplasmosis in the Brazilian Federal District Contribuição para a estimativa da freqüência de toxoplasmose em gestantes do Distrito Federal

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    Otávio de Tolêdo Nóbrega

    2005-08-01

    Full Text Available Acute infections by the protozoan Toxoplasma gondii during pregnancy (gestational toxoplasmosis are known to cause serious health problems to the fetus (congenital toxoplasmosis. In Brasília, there have been few studies on the incidence of toxoplasmosis. This report summarizes a retrospective study performed on 2,636 selected pregnant women attended by the public health system of Guará, a satellite-city of Brasília. In this survey, 17 cases of gestational toxoplasmosis were detected; 15 of which were primary maternal infection and the remaining 2 were consistent with secondary maternal infection. These results suggest an annual seroconversion rate of 0.64 percent (90 percent confidence interval: 0.38, 0.90.Infecções agudas pelo protozoário Toxoplasma gondii durante a gravidez (toxoplasmose em gestantes são conhecidas por causar sérios problemas de saúde ao feto (toxoplasmose congênita. Em Brasília, estudos sobre a incidência da toxoplasmose são escassos. Este relato resume um estudo retrospectivo realizado com um grupo selecionado de 2.636 gestantes assistidas pelo sistema público de saúde do Guará, cidade-satélite de Brasília. Nesta investigação, foram detectados 17 casos de toxoplasmose gestacional; 15 dos quais casos de infecção materna primária, e os 2 restantes consistentes com infecção materna secundária. Estes resultados sugerem uma taxa de soroconversão anual da ordem de 0,64 porcento (intervalo de confiança de 90 porcento: 0,38; 0,90.

  2. Avaliação do comportamento reológico de diferentes iogurtes comerciais Rheological evaluation of different commercial yoghurts

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    Thiago Rocha dos Santos Mathias

    2013-03-01

    Full Text Available A consistência e a viscosidade do iogurte são uns dos principais fatores envolvidos na qualidade e aceitação do produto. Dessa forma, este trabalho apresenta um estudo de comparação reológica entre iogurtes comerciais do Rio de Janeiro, Brasil, em cujas formulações constam diferentes espessantes. Foram utilizadas três grandes marcas do mercado e, entre os espessantes utilizados, estão: goma guar, goma xantana, goma carragena, goma alfarroba e carboximetilcelulose. Previamente às análises reológicas, as amostras de iogurtes foram submetidas à determinação do pH, da acidez (expressa em ácido láctico e da umidade. As curvas de fluxo e de viscosidade foram obtidas em reômetro rotacional Thermo Haake Mars com geometria placa/placa (35 mm de diâmetro, com variação de taxa de cisalhamento entre 0,02 e 100 s-1 (curva ascendente, e 100 e 0,02 s-1 (curva descendente, em um tempo total de 20 minutos. Foi determinada a histerese como a área entre as curvas e ajustados os modelos de Bingham, Casson, Herschel-Bulkley e Ostwald de Waele. Foram realizados também testes de tixotropia, pela medição da viscosidade em função do tempo a uma taxa constante de 100 s-1, por 10 minutos. Estes foram ajustados pelo modelo de Weltman. Além disso, foram verificadas alterações no comportamento reológico em função da variação de temperatura (4 a 24 ºC, cujos resultados foram avaliados pela Equação de Arrhenius. Todas as amostras de iogurte analisadas apresentaram comportamento pseudoplástico e tixotrópico. Todos os modelos foram bem ajustados para as curvas de fluxo, exceto o modelo de Weltman, que não representou bem os testes de tixotropia.Yoghurt consistency and viscosity are two of the major factors involved in product quality and acceptance. Thus this paper presents a comparative study of the rheology of commercial yoghurts in Rio de Janeiro, Brazil, whose formulations included different thickeners. Three major market brands

  3. Arte Rupestre en el Karst de Ojo Guareña (Merindad de Sotoscueva-Burgos : trabajos de documentación y estudio en «La Sala de La Fuente»

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    Juan A. Gómez Barrera

    2001-01-01

    Full Text Available La amplia nómina de autores que firman el presente artículo dan forma al equipo multidisciplinar que en 1995 inició un ambicioso proyecto, subvencionado por la Junta de Castilla y León, denominado «Trabajos de Documentación y Estudio del Arte Rupestre en el Karst de Ojo Guareña». El avance de sus primeros trabajos está recogido en el siguiente texto y fue presentado al Primer Congreso de Arqueología Burgalesa (1998, mas, al no haberse publicado éste, sigue aún inédito. Su interés, y de forma especial la continuidad de la investigación, aconseja a los autores su edición en Espacio, Tiempo y Forma con vistas a una mayor difusión del proyecto y, con ello, a un mejor conocimiento de la grafía rupestre de las galerías subterráneas del norte de la provincia de Burgos.The wide number of researchers who sign the present añide joined in the multi-discipline team that started an ambitious project, which was sponsored by the regional authority: Junta de Castilla y León, called «Records and Research on Cave Art at the karst in Ojo Guareña». The deveiopment of thelr first researches Is shown in the present Ítem and it was also presented in the First Burgos Archaeology Congress (1998, although it is still unavailable since it has never been published. Both, the Importance of its contents and specially the continuity of the research led its authors to publish this article in Espacio, Tiempo y Forma so that the project could be widely known and, at the same time, provide a better knowledge of rock graphics in the underground galleries which can be found in the north of Burgos province.

  4. Datación de las pinturas y revisión del Arte Paleolítico de Cueva Palomera (Ojo Guareña, Burgos, España

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    Soledad CORCHÓN RODRÍGUEZ

    2009-12-01

    Full Text Available RESUMEN: La datación de cuatro muestras de pintura negra (carbón, efectuadas por el sistema A.M.S., permite precisar la cronología y el contexto cultural de la Sala de Las Pinturas de Cueva Palomera (Ojo Guareña, Burgos. Las figuras parietales datadas incluyen, junto a sujetos de características paleolíticas, otra tradicionalmente considerada de «estilo esquemático» (postpaleolítico y de características propias de la Pintura Esquemática. Las cinco dataciones, sin embargo, ofrecen una gran coherencia interna, situando la totalidad de las muestras a finales del Interestadio Tardiglaciar (Allerôd o en la transición al Dryas reciente. La revisión del conjunto, muy homogéneo, de las figuras y signos de la Sala de Las Pinturas, permite definir el contexto de estas pinturas negras (Magdaloaziliense o Aziliense antiguo, y las características del Arte a finales del Paleolítico y comienzos del Epipaleolítico.ABSTRACT: The dating of four samples of black painting (coal using the A.M.S. system gives the exact chronology and cultural context of the Hall of Painting of the Cave of Palomera (Ojo Guareña, Burgos, Spain. The parietal figures dated include, together with subjects of Paleolithic characteristics, another traditionally considered as «schematic style» (post-Paleolithic and with characteristics peculiar to Schematic Painting. The five datings, however, offer great internal cohesion, situating all the samples at the end of the Late Glacial Interstage (Allerôd or in the transition to the recent Dryas. Revision of the very homogeneous set of the figures and signs in the Hall of Paintings allowed us to define the context of these black paintings (Magdalo-Azilian or Ancient Azilian and the characteristics of art the end of the Paleolithic and beginning of the Epipaleolithic.

  5. 低聚羧甲基瓜胶可再生凝胶体系的流变特性%Rheological Properties of the Regenerable Gel Systems of Low Molecular Weight Carboxymethyl Guar Gum

    Institute of Scientific and Technical Information of China (English)

    唐美芳; 苏创; 方波

    2011-01-01

    Low molecular weight guar gum fracturing fluids play an important role in the enhancement of oil-gas recovery for low permeable oil-gas reservoirs. The production of the regenerable cross-linked gel systems consisting of low molecular weight carboxymethyl guar gum (LMWCMG) and borax were studied. The effects of LMWCMG concentration and borate concentration on the formation and regeneration of the gel systems were investigated, and the stable can be regenerated LMWCMG cross-linked gel systems were obtained. Furthermore, the Theological properties of the gel systems with different regeneration times were studied. The results show that the regenerable gel systems possess good visco-elasticity and thixotropy, and shear thinning properties. Non-linear co-rotational Jeffreys model can be applied to describe the viscosity curves of the regenerable LMWCMG gel systems correctly, and using the model, the calculated values are in good agreement with the experimental data.%低聚瓜胶压裂液在低渗透油气田开发增产中有重要的应用.今对硼砂交联低聚羧甲基瓜胶可再生凝胶体系进行了研究.考察了低聚羧甲基瓜胶浓度、硼砂浓度对凝胶形成以及再生的影响,获得了结构稳定的可再生凝胶体系.考察了不同再生次数的凝胶体系的流变特性,结果表明可再生凝胶体系具有良好的黏弹性、触变性和剪切变稀性.低聚羧甲基瓜胶可再生凝胶体系的流变曲线可用非线性共转Jeffreys模型描述,模拟值与实验值吻合良好.

  6. A Sintaxe da Janela

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    Luís Antônio Jorge

    1993-12-01

    Full Text Available A preocupação fundamenta! do trabalho é de caráter ontológico: esboçar o problema das significações apriorísticas e autônomas dos elementos que compõem a sintaxe arquitetônica. O trabalho elege um desses elementos: a janela. Este artigo parte da aproximação histórica entre a janela e a secção da pirâmide visual, construção imaginária da teoria da perspectiva renascentista. A consideração da janela na linguagem arquitetônica implica reconhecer uma ambigüidade essencial: a janela deve inserir-se ordenadamente no plano da parede - raciocínio típico da modenatura - mas também relacionar-se com a imagem vista através dela, que extrapola o plano, ressaltando a tridimensionalidade - herança da perspectiva renascentista, fundamentada no espaço euclidiano. Ver janela ou ver através da janela são alternativas que se colocam tanto ao observador interno ao edifício, quanto ao externo. Texto de duplaface, a sintaxe da janela versa sobre o relacionamento desses dois lados

  7. Partially Hydrolyzed Guar Gum Increases  Ferroportin Expression in the Colon of Anemic  Growing Rats

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    Luciana Carvalho

    2017-03-01

    Full Text Available Studies have reported a positive effect of prebiotics on the bioavailability of iron. This study evaluated the effect of partially hydrolyzed guar gum (PHGG on iron absorption mechanisms in anemic rats. Male Wistar rats were fed 75g American Institute of Nutrition Rodent Diets for growth, pregnancy and lactation (AIN93‐G without iron for three weeks in order to induce iron deficiency anemia. Then they were fed a control diet (n = 12; without fiber or a diet with 7.5% of PHGG (n = 12, both without iron. Food intake, body growth and the feed efficiency coefficient (FEC were measured. The animals were euthanized after two weeks of treatment. The weight of the organs, the pH of the cecal content, and the hepatic iron and ferroportin expression in the cecum, duodenum, and liver were assessed. The intake of PHGG reduced food intake without affecting body growth, and there was a difference between the groups regarding the FEC (p = 0.026, with the highest value found in the PHGG group. The weight of the cecal content increased (p ≤ 0.001 and the pH of the cecal content was significantly lower in the PHGG group. The intake of PHGG significantly increased ferroportin expression in the cecum; however, the difference was not significant in the duodenum and the liver. PHGG seems to have a positive influence on iron absorption through transporter expression, and structural and physiological changes in the colon of anemic growing animals.

  8. Genealogias da alegria

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    Bruno Vasconcelos de Almeid

    2009-08-01

    Full Text Available Genealogias da Alegria tem por objetivo rastrear conceitos e construir planos sobre os quais podemos pensar a alegria como campo problemático. Trata-se de traçar linhas e acoplar fragmentos históricos e literários com a finalidade de subsidiar a discussão contemporânea em torno da alegria. O procedimento genealógico vale-se de trechos das obras de Calímaco e Luciano de Samósata, da elegia erótica romana e da alegria cristã. O passo seguinte consiste em rastrear o pensamento da alegria na obra de Gilles Deleuze, especialmente em três momentos: uma passagem de Diferença e Repetição, um trecho dos Diálogos extraído de Da Superioridade da Literatura Anglo-americana e a comunicação Pensamento Nômade no Colóquio de Cerisy. A alegria não se define como sentimento ou emoção; ao contrário, está ligada à premissa de afirmação da vida e ao caráter trágico da existência.

  9. A sabedoria da democracia

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    Gilson Matilde Diana

    2010-01-01

    Full Text Available http://dx.doi.org/10.5007/1677-2954.2010v9n1p131Durante a maior parte da história, a democracia foi desprezada como uma forma política inferior – a regra do povo, ou “dos muitos”, era logo identificada como a regra da ralé, da escória. Herdando do povo a volubilidade e a instabilidade, a democracia estava sempre perigosamente próxima do arbítrio e da anarquia, com toda a violência que se costuma associar a isso.

  10. High dilutions of euphorbia tirucalli L. (aveloz modify the viability and glycolytic metabolism of cell lines Altas Diluciones de Euphorbia tirucalli L. (arbusto de goma modifican la viabilidad y metabolismo glucolítico de líneas celulares Altas diluições de Euphorbia tirucalli L. (aveloz modificam a viabilidade e o metabolismo glicolítico de linhas celulares

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    Carla Holandino

    2008-09-01

    needed to better understand the mechanisms involved in this in vitro biological response to HDs. Keywords:  Euphorbia tirucalli L.; Aveloz; PFK-1; High Dilutions; Cell metabolism.   Altas diluições de Euphorbia tirucalli L. (aveloz modificam a viabilidade e o metabolismo glicolítico de linhas celulares Resumo O látex de Ephorbia tirucalli L. (aveloz é usado popularmente no tratamento de diversos tipos de câncer incluindo mama, próstata, pulmão e rim. Além do mais, altas diluições desse látex (latex-HDs têm sido utilizadas com sucesso no tratamento de tumores, embora o mecanismo dessa ação ainda seja desconhecido. O presente trabalho objetivou pesquisar os efeitos citotóxicos de látex-HDs em 2 linhas celulares humanas, incluindo melanócitos não tumorais (línha MelanA e células de câncer de mama humano (linha MCF7. As látex-HDs foram obtidas através de 2 procedimentos: diluição 1:100 em massa e agitação, com 2 solventes, água e etanol 70%, nas diluições homeopáticas 5, 15cH e 30cH de acordo com a Farmacopéia Homeopática Brasileira. As linhas celulares foram incubadas com látex-HDs 1% e 10% por 24 horas. Foram preparados controles similares sem o látex e incubados sob as mesmas condições. A viabilidade celular foi analisada através do método May-grunwald-Giemsa. A ultrastrutura celular foi analisada através de microscopia eletrônica de transmissão. As alterações metabólicas foram detectadas por ensaio de espectrofotometria para a atividade da anzima 6-fosfofructo-1-quinase (PFK-1. Látex-Hds em etanol 1% não induziram qualquer alteração na viabilidade das células MelanA, mas Aveloz 15cH induziu aumento da

  11. Corporeidade da voz : estudo da vocalidade poetica

    OpenAIRE

    Fernando Manoel Aleixo

    2004-01-01

    Resumo: Este material é o resultado da investigação prática da voz realizada a partir do desenvolvimento do princípio da sabedoria sensível do corpo. O texto expõe as etapas percorridas no levantamento de experiências e reflexões pedagógicas sobre a voz do ator, no estabelecimento de referências sobre o corpo e o aprendizado sensível e, também, no processo de composição poética do espetáculo teatral Voz Mercê Abstract: This material springs from a practical investigative work on voice base...

  12. Modelagem da laringe: da biologia ao computador

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    Marcelo de Oliveira Rosa

    2016-01-01

    Full Text Available Neste trabalho apresentamos uma descrição daanatomia e fisiologia da laringe, enfatizando os aspectos relevantes à fonação. A partir destes aspectos, a modelagem da laringe é apresentada. O principal objetivo de modelara laringe é representar de uma maneira simples esse órgãoatravés de equações matemáticos intimamente relacionadoscom características fisiológicas. Equações aerodinâmicase viscoelásticas são simplificadas de acordo com as pesquisas,sempre buscando simplicidade e aplicabilidade computacional. Assim, pesquisadores podem compreender melhor a laringe e a fala humana em termos dos efeitos linguísticos, cirúrgicos e computacionais produzidos pelamovimentação desse órgão. Palavras-chave: Laringe, modelagem, sinal glotal,produção da fala.

  13. Caracterização da diversidade genética entre acessos crioulos de feijão (Phaseolus vulgaris L. coletados em Santa Catarina por marcadores RAPD Characterization of the genetic diversity of landraces of common bean (Phaseolus vulgaris L. collected in Santa Catarina State by RAPD markers

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    Márcio Fonseca de Carvalho

    2008-09-01

    Full Text Available O conhecimento da diversidade genética, por meio da dissimilaridade entre os genótipos, permite a organização, a amostragem e a utilização eficiente do germoplasma em programas de melhoramento genético. O objetivo deste trabalho foi estimar a dissimilaridade entre acessos crioulos de feijão coletados no Estado de Santa Catarina, integrantes do banco ativo de germoplasma de feijão da UDESC e de três cultivares comerciais ("Pérola", "SCS 202-Guará" e "BRS Valente", por meio de marcadores moleculares RAPD. Foram utilizados 21 iniciadores decâmeros que permitiram a visualização de 96 bandas, sendo que 41 (42,7% apresentaram polimorfismo entre os acessos estudados, resultando em bandas entre 650 e 2000pb. A dissimilaridade foi calculada utilizando-se o coeficiente de Sorensen-Dice e o agrupamento foi realizado pelo método UPGMA. Os acessos foram separados em dois grupos principais, com dissimilaridade relativamente alta, quando comparada com a dissimilaridade observada dentro de cada grupo. Os dois grupos formados indicam os centros de domesticação, Mesoamericano ou Andino, dos acessos analisados. A dissimilaridade entre as cultivares avaliadas ("SCS 202-Guará", "BRS Valente" e "Pérola" é baixa (0,15, se comparada com a dissimilaridade entre os demais acessos do banco de germoplasma (0,65. A menor dissimilaridade entre os acessos estudados (BAF63 e BAF04 foi de 0,02. A inexistência de acessos repetidos reforça a necessidade de novas coletas de germoplasma, o que resultará em um banco de germoplasma de feijão mais representativo da variabilidade genética remanescente em Santa Catarina.The knowledge of the genetic diversity through the divergence among the genotypes allows the organization of the germplasm, sampling and efficient utilization in breeding programs. The objective of this study was to analyze the dissimilarity among germplasm collected in Santa Catarina State, stored in UDESC germplasm active bank of common bean

  14. Métodos para abandono do tabagismo e tratamento da dependência da nicotina Methods for smoking cessation and treatment of nicotine dependence

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    Aracy Pereira Silveira Balbani

    2005-12-01

    Full Text Available O tabagismo está relacionado a 30% das mortes por câncer. É fator de risco para desenvolver carcinomas do aparelho respiratório, esôfago, estômago, pâncreas, cérvix uterina, rim e bexiga. A nicotina induz tolerância e dependência pela ação nas vias dopaminérgicas centrais, levando às sensações de prazer e recompensa mediadas pelo sistema límbico. É estimulante do sistema nervoso central (SNC, aumenta o estado de alerta e reduz o apetite. A diminuição de 50% no consumo da nicotina pode desencadear sintomas de abstinência nos indivíduos dependentes: ansiedade, irritabilidade, distúrbios do sono, aumento do apetite, alterações cognitivas e fissura pelo cigarro. O aconselhamento médico é fundamental para o sucesso no abandono do fumo. A farmacoterapia da dependência de nicotina divide-se em: primeira linha (bupropiona e terapia de reposição da nicotina, e segunda linha (clonidina e nortriptilina. A bupropiona é um antidepressivo não-tricíclico que age inibindo a recaptação de dopamina, cujas contra-indicações são: epilepsia, distúrbios alimentares, hipertensão arterial não-controlada, abstinência recente do álcool e uso de inibidores da monoaminoxidase (MAO. A terapia de reposição de nicotina pode ser feita com adesivos e gomas de mascar. Os efeitos da acupuntura no abandono do fumo ainda não estão completamente esclarecidos. As estratégias de interrupção abrupta ou redução gradual do fumo têm a mesma probabilidade de sucesso.Smoking is related to 30% of cancer deaths. It is a risk factor for respiratory tract, esophagus, stomach, pancreas, uterine cervix, kidney and bladder carcinomas. Nicotine induces tolerance and addiction by acting on the central dopaminergic pathways, thus leading to pleasure and reward sensations within the limbic system. It stimulates the central nervous system (CNS, enhances alertness and reduces the appetite. A 50% reduction of nicotine consumption may trigger withdrawal

  15. A importância das plantações de eucalipto na conservação da biodiversidade

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    Vagner de Araujo Gabriel

    2013-06-01

    Full Text Available Nas últimas décadas a expansão de plantações de Eucalyptus sp. foi notável no Brasil, destacando-se no cenário mundial. Diversos estudos revelam que tais plantações, especialmente aquelas respaldadas por instrumentos de certificação, podem trazer benefícios de cunho social e ambiental. Este trabalho apresenta dados coletados no período de 2002 a 2011 sobre a riqueza de plantas, aves e mamíferos em fazendas de plantação de eucalipto no Brasil. Discute-se sobre a importância dessas fazendas na conservação da biodiversidade, em que já foram registradas diversas espécies de plantas arbustivo-arbóreas, aves e mamíferos de médio e grande porte, respectivamente. Foi registrada a ocorrência de regeneração de plantas ameaçadas de extinção nos talhões de eucalipto: Araucaria angustifolia, Couratari asterotricha, Buchenavia hoehneana, Dalbergia nigra, Ocotea catharinensis e Ocotea porosa. Quanto às espécies da fauna ameaçadas de extinção, a águia-cinzenta (Urubitinga coronata, o chauá (Amazona rhodochorytha, o lobo-guará (Chrysocyon brachyurus, o tamanduá (Myrmecophaga tridactyla e a anta (Tapirus terrestris já foram observados. Plantações florestais e fragmentos compostos por vegetação secundária figurarão entre os principais elementos das paisagens tropicais futuras. Desta forma, não se pode negligenciar a contribuição das plantações de eucalipto na conservação da biodiversidade.

  16. A ciclovia da morte

    OpenAIRE

    Gois, Ancelmo

    2016-01-01

    De acordo com levantamento da FGV/DAPP, houve mais de 36 mil menções ao desabamento no Twi er, até o fim da tarde de ontem, com palavras como "vergonha", "incompetência" e "culpa" em destaque, além de muitas criticas ao prefeito Eduardo Paes.

  17. Influência da mono-hidrogenação da fração C5 na síntese do TAME usando Amberlyst 15 como catalisador Influence of mono-hydrogenation of C5 cut on the synthesis of TAME using Amberlyst 15

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    Gilberto da Cunha Gonçalves

    2001-05-01

    Full Text Available No presente trabalho, foi estudada a síntese do TAME, em fase líquida, a partir de uma fração C5 e metanol, utilizando Amberlyst 15 como catalisador. A fração C5 utilizada possui uma diolefina, que tem uma alta tendência à formação de gomas e um alto teor de mono-olefinas. Deste modo, o objetivo deste trabalho foi avaliar o efeito da mono-hidrogenação da fração C5 na síntese do TAME. A hidrogenação foi feita a 80oC e 10 kgf/cm2 de H2, usando um catalisador 0,3% Pt/Al2O3. A diolefina foi totalmente hidrogenada e o teor de mono-olefinas significativamente reduzido sem um decréscimo apreciável no teor de isoamilenos reativos. A eterificação foi feita em um reator tipo batelada de 250 mL, com agitação magnética. A temperatura foi variada na faixa de 50 a 90oC, com uma pressão de 10 kgf/cm2 e razão molar isoamileno/metanol de aproximadamente um. Os produtos de reação foram analisados por cromatografia gasosa. A conversão total observada foi aproximadamente a mesma para o os cortes original e mono-hidrogenado. Entretanto, os produtos obtidos utilizando a fração C5 original apresentaram cheiro forte e coloração, mesmos para os testes a temperaturas mais baixas, que são características da formação de gomas. Por outro lado, quando a fração mono-hidrogenada foi usada na eterificação, o cheiro forte e coloração não foram observados. Portanto, a mono-hidrogenação da fração C5 contendo os isoamilenos reativos é necessária para que o TAME produzido na reação de eterificação possa ser adicionado à gasolinaTAME was synthesized in liquid phase from refinery C5 cut and methanol using Amberlyst 15 as catalyst. The C5 stream contains mainly mono-olefins and, in a less amount, a diolefin, which have a high gum formation tendency. The main purpose of this research was to evaluate the effect of mono-hydrogenation of C5 cut on TAME synthesis. The hydrogenation step was carried out at 80 oC and 10 kgf/cm2 of H2

  18. Cartografia da paisagem alterada

    Directory of Open Access Journals (Sweden)

    Simone Cortezão

    2011-04-01

    Full Text Available O presente trabalho de pesquisa surge da investigação de paisagens alteradas, áreas pós-industriais e da geografia urbana que é conformada pela indústria. A preocupação principal é revê-las como espaço de investigação crítica sob o ponto de vista particular, integradas às noções da peculiar natureza industrial com suas consequentes transformações na paisagem, além das relações do indivíduo com esse novo meio produzido. “Cartografia da paisagem alterada” é uma pesquisa que indicia a paisagem alterada em pelo menos dois estratos: um que é o da construção da geografia da cidade pela indústria, e o outro que é a paisagem alterada subjetivamente, o que configura uma crítica e uma reação à conformação sócio geográfica em outros parâmetros - da proximidade, da experiência vivida e da construção de um vocabulário próprio.  A pesquisa teórica sobre áreas pós-industriais, associada a referências nas artes e arquitetura, constitui o primeiro estrato. Teorias e procedimentos artísticos de Robert Smithson, Joseph Beuys e Rem Koolhaas fornecem material para o segundo, mediante a pesquisa do cotidiano no lugar, a região do Vale do Aço, que se configura em um guia - glossário

  19. GERONTOLOGIA: ESTADO DA ARTE

    Directory of Open Access Journals (Sweden)

    Vera M.A.Tordino Brandão

    2010-02-01

    Full Text Available O Programa de Gerontologia da PUC desenvolve pesquisas focando o ser na perspectiva do envelhecimento. As atividades são interdisciplinares e reúnem docentes, alunos e ex-alunos. Nesta mesa redonda apresentamos um panorama sobre estes estudos. Na área da educação e comunicação o foco está centrado na longevidade e na preparação e representação social da velhice. São ressaltadas como temáticas: a formação continuada de profissionais e pesquisadores; o significado da religiosidade/espiritualidade ao longo da trajetória, e sua repercussão na qualidade de vida do idoso; os programas sócio-educacionais para idosos e concepções sobre educação; o monitoramento da mídia na cobertura da crescente longevidade e seus impactos. Em identidade e modos de morar reflete-se sobre soluções planejadas e sua adequação para a inclusão do envelhecimento populacional como questão fundamental, que implica a elaboração de novas políticas, investigações e, especialmente, apresenta-se como questão a ser analisada, refletida e vivenciada pela sociedade em geral. Quanto à saúde, o Programa desenvolve várias pesquisas numa abordagem interdisciplinar tendo como objetos de estudo: a terapia assistida com animais direcionada a idosos com diagnóstico de Alzheimer; o acompanhamento terapêutico e o atendimento psicoterapêutico em grupo, a aplicação da técnica de Calatonia em idosos moradores de ILPI, além da investigação sobre impasses clínicos no idoso frágil. Palavras-chave: gerontologia, longevidade, envelhecimento

  20. CONDICIONANTES DA COMPETITIVIDADE EMPRESARIAL

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    José Luiz Contador

    2010-03-01

    Full Text Available Este trabalho examina teoricamente os fatores determinantes da competitividade do produto e do negócio, imprescindíveis à elaboração de estratégias competitivas que visam à obtenção e sustentação de vantagens competitivas. Esse tema é objeto tanto da área de marketing estratégico quanto da de estratégia empresarial. Nas duas áreas, há um ponto de consenso que afirma que a empresa deve diferenciar sua oferta para conquistar e manter vantagem competitiva. Mas, os estudos conduzidos por meio do modelo de Campos e Armas da Competição revelaram que a empresa pode diferenciar seu produto e/ou serviço de modo mais amplo, levando em consideração, na formulação da sua estratégia competitiva, também o campo da competição, quer do produto, quer dela própria. Assim, o objetivo deste artigo é evidenciar que, para a empresa ser competitiva, além de diferenciar seu produto e/ou seu serviço no sentido tradicional, ela precisa: 1 diferenciar seu produto incluindo a definição em quais campos vai competir em cada segmento; e 2 escolher as armas da competição que irá utilizar e definir a intensidade de cada arma. Para atingir tal objetivo, foram necessários vários conceitos do modelo de Campos e Armas da Competição: campo da competição, arma da competição, tese do modelo, configuração dos campos da competição, campo coadjuvante, produto coadjuvante e par produto-mercado. Como uma proposta inovadora sempre desperta dúvida, é mostrado o processo de validação do modelo de Campos e Armas da Competição e são discutidas sua universalidade, consistência e completude.

  1. Het Italiaanse voorzetsel da

    NARCIS (Netherlands)

    Boer, M.G. de

    2010-01-01

    SAMENVATTING In een voorzetselstudie in het kader van Jackendoffs semantische theorie wordt het sterk polyseme Italiaanse voorzetsel da geanalyseerd als een verzameling deelbetekenissen waarbij de meeste door een of meer semantische regels afgeleid kunnen worden van de basisbetekenis ruimtelijke

  2. Het Italiaanse voorzetsel da

    NARCIS (Netherlands)

    Boer, M.G. de

    2010-01-01

    SAMENVATTING In een voorzetselstudie in het kader van Jackendoffs semantische theorie wordt het sterk polyseme Italiaanse voorzetsel da geanalyseerd als een verzameling deelbetekenissen waarbij de meeste door een of meer semantische regels afgeleid kunnen worden van de basisbetekenis ruimtelijke He

  3. ESPECTROS INFRAVERMELHOS DA CREATINA

    Directory of Open Access Journals (Sweden)

    Kumiko K. Sakane

    2011-08-01

    Full Text Available São apresentados espectros infravermelhos da creatina, na faixa de 4000 a 400 cm−1. Os resultados são comparados com espectros observados e calculados, publicados na literatura.

  4. Impacto ambiental da apicultura

    OpenAIRE

    1999-01-01

    A cultura da abelha doméstica Apis. mellifera L. ou apicultura é conhecida desde a antiguidade, sendo o mel uni alimento natural corrente entre os povos primitivos. Pinturas rupestres mostram que desde o neolítico o homem era atraído pelo mel, pois tentava recolher ninhos de abelhas selvagens e instalava-os em cavidades naturais das rochas, muito perto da sua habitação.

  5. 瓜尔胶和黄原胶对马铃薯淀粉及其变性淀粉糊化和流变性质的影响%Effects of Guar Gum and Xanthan Gum on Pasting and Rheological Properties of Native and Modified Potato Starch

    Institute of Scientific and Technical Information of China (English)

    蔡旭冉; 顾正彪; 洪雁; 张雅媛; 朱玲

    2011-01-01

    In this study,pasting and rheological properties of native potato starch,potato starch phosphate ester and cationic potato starch were determined in the respective presence and simultaneous absence of guar gum and xanthan gum.The results indicated that the presence of guar gum enhanced the peak viscosity and pasting temperature of all three kinds of potato starches and deteriorated the thermal stability of starch pastes.The peak viscosities of native potato starch and potato starch phosphate ester rose and the thermal stability and pasting temperature declined due to the presence of xanthan gum,compared to opposite changes observed for cationic potato starch.Dynamic rheological studies revealed that the addition of xanthan gum considerably raised the G' and G'' values and declined the tanδvalue of each kind of potato starch.The dynamic rheological properties of cationic potato starch were affected most obviously.By contrast,guar gum had no obvious effect on the dynamic rheological properties of all three kinds of potato starches.In static rheological studies,we found that starch pastes remained pseudo-plastic fluids despite the presence of either guar gum or xanthan gum,with shorted lag ring area and improved stability.Native potato starch and potato starch phosphate ester were more obviously affected than cationic potato starch.Moreover,xanthan gum had more obvious effect than guar gum.Further,our studies demonstrated that gum-starch interactions play a vital role in pasting and rheological properties of gum-starch complexes.%研究瓜尔胶和黄原胶对马铃薯淀粉、马铃薯磷酸酯淀粉和马铃薯阳离子淀粉糊化和流变性质的影响。糊化性质实验表明瓜尔胶增加了3种淀粉的峰值黏度和成糊温度,降低了淀粉糊的热稳定性。黄原胶降低了马铃薯淀粉和马铃薯磷酸酯淀粉的峰值黏度并提高了糊的热稳定性和成糊温度,但对马铃薯阳离子淀粉起相反作用。动态流变实验

  6. Indicação de punção lombar para diagnóstico da neurossífilis

    Directory of Open Access Journals (Sweden)

    Filipe Augusto Gava Martins

    2015-08-01

    Full Text Available A sífilis é um agravo infectocontagioso causado pelo Treponema pallidum, de transmissão predominantemente sexual, que afeta 12 milhões de pessoas por ano no mundo. Se não curada em suas fases iniciais, predispõe a complicações potencialmente graves. Uma dessas complicações é a neurossífilis, caracterizada pela invasão do sistema nervoso central pelo T. Pallidum em qualquer fase da história natural da infecção, cuja mortalidade ultrapassa 60%. Em pessoas com HIV, essa complicação pode ser mais frequente, surgir após um menor período de latência e ser mais agressiva.Na maioria das vezes, a neurossífilis é assintomática ou se apresenta por meio de manifestações clínicas pouco específicas que demandam alto índice de suspeição e propedêutica laboratorial invasiva. O diagnóstico é feito através de provas sorológicas ou de biologia molecular no líquor. A controvérsia é sobre a indicação desse diagnóstico e respectivo tratamento nos casos assintomáticos, principalmente em se tratando de pessoas que vivem com o HIV. Esta revisão narrativa da literatura concluiu que a punção lombar propedêutica da neurossífilis está indicada em pessoas que apresentam sororreagência ao VDRL, associado a uma ou mais das seguintes condições: manifestações neurológicas na esfera motora, sensitiva ou cognitiva; sintomatologia sifilítica ou VDRL maior que 1:8 pós-tratamento, descartada reinfecção; pessoas com HIV na presença de CD4 menor que 351 células/mm3 e VDRL maior ou igual a 1:32; e evidência de doença sifilítica terciária não neurológica em atividade (goma ou aortite. Feito o diagnóstico a partir desses critérios, o tratamento específico deverá ser administrado mesmo nos casos assintomáticos.

  7. EFECTO DE LA ADICIÓN DE CARRAGENINA KAPPA I.II Y GOMA TARA SOBRE CARACTERÍSTICAS DE CALIDAD DEL JAMÓN DE CERDO PICADO Y COCIDO EFFECT OF THE ADDITION OF KAPPA I.II CARRAGEENAN AND TARA GUM ON QUALITY CHARACTERISTICS OF COOKED AND CHOPPED PORK HAMS

    Directory of Open Access Journals (Sweden)

    Diego Alonso Restrepo Molina

    2010-12-01

    Full Text Available Se evaluaron sinéresis, color y dureza instrumental y, sensorialmente las características de olor, sabor, color y dureza en jamones inyectados, cocidos y picados de cerdo, los cuales se habían elaborado aplicando en la salmuera de inyección una mezcla de hidrocoloides compuesta por carragenina kappa I.II y goma tara en una proporción de 79:21, en niveles del 1% y 1,2%, usando tres repeticiones para el estudio. Los jamones así elaborados se compararon contra un jamón testigo, elaborado sin el uso de estos hidrocoloides. Los valores obtenidos para los atributos, se analizaron mediante un diseño de una sola vía, con 5 repeticiones en el tiempo (0, 10, 20, 28 y 34 días, dando un arreglo factorial. Los resultados muestran que el tratamiento 2 (1,2% presentó la menor liberación de agua y la mayor dureza. No se registró diferencia entre los tratamientos y el testigo para la característica elasticidad. El testigo mostró las mejores características de color, olor y sabor sensoriales. La edad influyó en las características dureza y sinéresis en forma determinante, señalando el período desde el día 15 hasta el día 28 como aquel en que más se agudiza la sinéresis, siendo ésta más notable en el testigo que no contenía hidrocoloide.Characteristics of quality, color, texture and sineresis (instrumental and, odor, flavor, color and hardness (sensory of injected, cooked and chopped pork hams were assessed, which were manufactured using a mix of hydrocolloids in the brine of injection comprised by kappa I.II carrageenan and tara gum in a 79:21 ratio, at levels of 1% and 1.2%, using three replicates for the study; the finished hams were compared with a control ham, manufactured without the use of these hydrocolloids. The values obtained for the attributes, were analyzed through a one way design, with 5 repetitions in time (0, 10, 20, 28 and 34 days, providing a factorial arrangement. The results showed that the treatment 2 (1

  8. Em defesa da semiodiversidade

    Directory of Open Access Journals (Sweden)

    Antônio Risério

    2008-11-01

    Full Text Available Semiodiversidade é um conceito que denomina a esfera da vida que se refere particularmente ao reino dos signos. Embora tenha sido criado no contexto das discussões sobre a biodiversidade, ele compreende um amplo campo que é quase desconhecido. Contrariamente à biodiversidade, não é um termo da moda, ainda que abarque um amploconjunto de problemas. As mais diferentes linguagens, signos e códigos culturais encontram lugar no domí­nio da semiodiversidade. Neste artigo a defesa da semiodiversidade é uma forma de preservar a vida humana neste momento da aventura do homem no planeta.Abstract: Semiodiversity is a concept to denominate the sphere of life that refers, particularly, to the realm of signs. Although it has been created in the context of biodiversity, it assigns a wider territory, which is almost unknown. Contrary to biodiversity, it is not a trendy' term, even though embeding a much wider scope. The most different languages, signs and cultural codes can be found in the domain of semiodiversity. In this article, the defense of semiodiversity is a way to preserve human life at this moment of humanadventure on Earth.

  9. da etiologia ao tratamento

    OpenAIRE

    Soares, Tânia Alexandra Maia

    2013-01-01

    Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina Dentária A luxação da articulação temporomandibular (ATM) ocorre quando o côndilo mandibular se desloca para fora da fossa mandibular e não é capaz de retornar. As manifestações clinicas mais frequentes desta patologia são: dificuldade de fechar a boca, depressão pré-auricular, sialorréia, tensão dos músculos da mastigação e dor severa na reg...

  10. Fundamentos da psicologia social

    OpenAIRE

    Kruger, Helmuth Ricardo

    1984-01-01

    O tema central deste estudo é o dos fundamentos da Psicologia Social. Neste sentido, foram examinados pressupostos ontológicos, epistemológicos, lógicos e axiológicos mas, também, as bases conceituais, teóricas e metodológicas deste setor da Psicologia contemporânea. A justificar este empreendimento, encontram-se duas suposições: a de que qualquer ciência é inexoravelmente construída sobre postulados metafísicos e lógicos, e a de que a falta de clareza em relação a estes impede a instalação d...

  11. DA LITERATURA AO PENSAMENTO

    Directory of Open Access Journals (Sweden)

    Gustavo Bernardo

    2012-07-01

    Full Text Available Apresento uma concepção pessoal do ensino de literatura, condensando a discussão das principais questões que o afetam: a singularidade da disciplina entre as demais disciplinas escolares; a crítica do realismo como valor dominante; a importância do exemplo; os efeitos da desvalorização salarial e moral do professor; a praga das adaptações literárias para jovens. A partir dessas questões, apresento cinco modos de leitura e ensino do texto literário, a saber: ler como resposta; ler como pergunta; a leitura ingênua; a leitura crítica; a leitura teórica. Concluo pela necessidade de proteção radical à dúvida, fundadora da literatura e do próprio pensamento.

  12. Medidas de rentabilidade da empresa

    OpenAIRE

    Mota, Haroldo Moura Vale

    2010-01-01

    Faz uma avaliação da medida de retorno contábil da corporação (return on investment - ROI) à luz da verdadeira medida de retorno econômico (taxa interna de retorno - TIR). Apresenta modelo para cálculo da taxa interna de retorno da empresa, o qual é submetido à testes para aferir o seu valor informativo. Utilizando o conceito de taxa interna de retorno da corporação, é criado um modelo denominado de Modelo de Avaliação Econômica Base Caixa, aplicável a uma empresa b...

  13. Da Vinci Linjen

    DEFF Research Database (Denmark)

    Nissen, Poul

    Afsluttende evalueringsrapport fra følgeforskningen gennem tre år i forbindelse med dety pædagogiske arbejde på Blåbjerggårdskolens Da Vinci Linje for skolemotiverede og underpræsterende elever på 7. til 9. klassetrin.......Afsluttende evalueringsrapport fra følgeforskningen gennem tre år i forbindelse med dety pædagogiske arbejde på Blåbjerggårdskolens Da Vinci Linje for skolemotiverede og underpræsterende elever på 7. til 9. klassetrin....

  14. GESTAO DA AGRICULTURA URBANA

    OpenAIRE

    2014-01-01

    Este artigo apresenta o conceito de agricultura urbana e sua contribuição para a integração da atividade agrícola com o ambiente urbano, incentivando o desenvolvimento de cidades sustentáveis. Analisa o grau de complexidade encontrado pelas autoridades ao criar e aplicar politicas pública onde os sistemas urbanos de suprimento de alimentos não são acessíveis a toda a população. Traz luz a algumas das questões diretamente relacionadas à implantação da agricultura em grandes centros urbanos, ta...

  15. Profilaxia da peste

    Directory of Open Access Journals (Sweden)

    Renato dos Santos Araújo

    1967-12-01

    Full Text Available O autor parte da premissa de que a profilaxia da doença infecciosa decorre do encadeamento epidemiológico: fonte de infecção-veículo transmissor - receptivel, para explicar a da peste, baseada no mesmo princípio. Depois de citar os 4 principais complexos epidemiológicos da peste e afirmar que tôda a profilaxia da doença consiste em atingir os dois primeiros elos dessas cadeias e proteger o último, passa a classificar os vários métodos profiláticos empregados em 2 grandes grupos: o das medidas destrutivas ou provisórias e o das medidas supressivas ou definitivas. Entre as primeiras arrola a desratização e a despulização, às quais acrescenta o tratamento e isolamento do doente e do portaãor, e entre as segundas inclui a anti-ratização e a imunização. A seguir, passa a explicar em que consistem essas várias medidas profiláticas e quais os agentes de que se tem lançado mão para executá-las, expendendo ao curso dessa exposição o conceito que formula a respeito de cada uma delas, à guisa de apreciação do seu valor relativo. Enaltece sobretudo as medidas supressivas ou definitivas, às quais empresta a maior significação na luta antipestosa, chamando a atenção, em especial, para a necessidade de estudos imunológicos para aperfeiçoamento do poder imunitário das vacinas de germes vivos avirulentos, que considera um grande recurso para a profilaxia da doença, sobretudo para a proteção do rurícola, cujo labor e modo de vida o expõem inevitavelmente a se infectar, por ocasião da ocorrência de epizootias de origem silvestre. Concluída essa primeira parte, passa a fazer o histórico de como se desenvolveu a campanha contra a peste, no Brasil, desde a época da sua invasão em 1899 pelo pôrto de Santos até os nossos dias. Nesse histórico, detem-se um pouco para expôr a atuação do extinto Serviço Nacional de Peste, o qual, criado em 1941, após a reorganização do Departamento Nacional de Saúde, passou

  16. O livro da alma

    Directory of Open Access Journals (Sweden)

    Oliver Tolle

    2016-12-01

    Full Text Available Trata-se de compreender os pressupostos da filosofia concreta pretendida por Johann Gottfried Herder (1744-1803 em uma série de textos redigidos durante as décadas de 1760-70. Se, por um lado, Herder demonstra afinidade com a mesma harmonia preestabelecida que está na base de leibnizianos como Gottsched e Baumgarten, por outro, ele aprofunda a discussão sobre a origem do conhecimento humano ao reduzir a importância de juízos de valor universal e acentuar a necessidade de uma aproximação constante das sensações que se agitam obscuramente no fundo da alma. Disso resulta uma concepção inusitada de sabedoria, a qual depende de uma renúncia à posse confortável de conhecimentos abstratos e da aceitação da natureza cambiante e apenas parcialmente perscrutável daquilo que nos move. Se com isso perde-se a certeza, abre-se em contrapartida uma dimensão essencialmente ativa e sensível de realização no mundo.

  17. O esvaziamento da cultura

    Directory of Open Access Journals (Sweden)

    Andressa Paula de Andrade

    2015-01-01

    Full Text Available Trata-se da resenha da obra "A civilização do espetáculo: uma radiografia do nosso tempo e da nossa cultura" de autoria de Mario Vargas Llosa, ganhador do Nobel de Literatura em 2010. O trabalho busca compreender este tempo em que a diversão assume maior relevância em detrimento da cultura profunda e reflexiva. Destarte, a todo momento se olha para o passado com vistas a examinar este fenômeno que se tornou um verdadeiro "esvaziamento cultural". Outrossim, busca-se elucidar que embora ocorra um progresso científico, acesso a educação e a tecnologia de forma vertiginosa, isso não significa que a as artes avançaram na mesma velocidade, pelo contrário, acabou estagnando e já não visa mais a modificação de estruturas, mas apenas entreter.

  18. O labirinto da contemporaneidade

    Directory of Open Access Journals (Sweden)

    Lang, Charles Elias

    2011-01-01

    Full Text Available O presente trabalho discute a modernidade e a produção da subjetividade contemporânea. Toma-se como modelo o labirinto de Eco (1985. Existem três tipos de labirintos: o labirinto clássico, o maneirístico, e a rede. O clássico é unicursal. Assim que se entra, a única coisa que se pode fazer é chegar ao centro e, do centro, só o que se pode fazer é encontrar uma saída. O maneirístico propõe escolhas alternativas. Todos os percursos levam a um ponto morto, com exceção de um que leva à saída. Na rede, cada ponto pode ter conexão com qualquer outro ponto. Se os labirintos anteriores têm um interior e um exterior, a rede, extensível ao infinito, não tem nem um dentro nem um fora. A partir deste modelo discute-se a produção de individualidades e subjetividades, do corpo como meio de comunicação e a produção de imagens do corpo através da mídia

  19. Dj Da Hai

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Miko Da Hai is DJ at a Xi’an disco bar. At work, in his cool attire, the pulsing disco beat punctuated by his distinctive vocal commentary, he makes a striking impression. The job having come his way by chance, Miko is now a skilled and experienced DJ of eight years’ standing. This may be

  20. Quixotada linguística: para além da bravura e das estabilidades, invenções dos que não podem correr

    Directory of Open Access Journals (Sweden)

    Miguel Angel Schmitt Rodriguez

    2013-12-01

    Full Text Available http://dx.doi.org/10.5007/1984-784X.2013v13n20p112 Dom Quixote constituiu-se como um clás­sico da lite­ratura ocidental através das in­terpretações ca­nônicas que enfati­zaram as qualidades pedagó­gicas que as aventuras do herói cervantino possi­bili­tam ao leitor. No presente artigo, entretanto, busca-se pensar tal texto para além dos ensina­men­tos humanistas que a tradição procurou des­tacar. Insinua-se, por exemplo, que a morte de Deus anunciada por Nietzsche po­deria guar­dar relações íntimas com os disparates qui­xotes­cos. Busca-se, ademais, enfati­zar a presença de uma escritura que des­taca a instabilidade dos signi­ficantes e que apontaria para uma prática de ope­ra­ção sobe­rana ou de experiência inte­rior tal qual sugerida por Georges Bataille.

  1. Quixotada linguística: para além da bravura e das estabilidades, invenções dos que não podem correr

    Directory of Open Access Journals (Sweden)

    Miguel Angel Schmitt Rodriguez

    2013-12-01

    Full Text Available Dom Quixote constituiu-se como um clás­sico da lite­ratura ocidental através das in­terpretações ca­nônicas que enfati­zaram as qualidades pedagó­gicas que as aventuras do herói cervantino possi­bili­tam ao leitor. No presente artigo, entretanto, busca-se pensar tal texto para além dos ensina­men­tos humanistas que a tradição procurou des­tacar. Insinua-se, por exemplo, que a morte de Deus anunciada por Nietzsche po­deria guar­dar relações íntimas com os disparates qui­xotes­cos. Busca-se, ademais, enfati­zar a presença de uma escritura que des­taca a instabilidade dos signi­ficantes e que apontaria para uma prática de ope­ra­ção sobe­rana ou de experiência inte­rior tal qual sugerida por Georges Bataille.

  2. Transitoriedade ou o desterro da certeza

    Directory of Open Access Journals (Sweden)

    Paulo José Carvalho da Silva

    2012-12-01

    Full Text Available O tema da transitoriedade era lugar-comum da medicina da alma da primeira modernidade. Este artigo analisa algumas dessas fontes para mostrar como a dor do tempo e os males da alma atinentes eram relacionados a um modo de encarar a fugacidade do tempo e a fragilidade da vida. Dá-se destaque, sobretudo, às construções em torno da condição humana enquanto desterro da certeza.

  3. 烯基琥珀酸酐改性瓜尔胶的合成及其凝胶破胶性能研究%Synthesis and Property Study of Gel and Gel Breaking for Guar Gum Modified by Alkenyl Succinic Anhydride

    Institute of Scientific and Technical Information of China (English)

    薛贝; 沈一丁; 杨晓武; 李培枝; 王健

    2012-01-01

    A novel guar gum modified by alkenyl succinic anhydride (ASA) was synthesized by dry preparation method when the catalyst was NaHCO3. The optimum reaction condition of the gum was obtained as follows: guar gum and ASA in mass ratio 7:1, 60℃ reaction temperature, 10 hrs reaction time and 0.4% NaHCO3dosage. The surface tension of 0.4% modified guar gum solution was of 35.29 raN/m, and that of the gelout solution, which was broken by ammonium persulfate, was of 29.65 mN/m. The interf~ial tension of gelout solution and kerosene was of 2.27 raN/m, and the residue content was of 300 mg/L. It was showed that the properties of temperature and shear resistance were improved after the guar gum modified. When the shearing rate or temperature was low, the viscosity of modified gum decreased, which was beneficial to reduce the flowing friction of fluid in pipeline. On the contrary, when the shearing rate or temperature was high, the viscosity increased, which was conducive to bring sand fracturing in later process.%以碳酸氢钠为催化剂,采用干法制备烯基琥珀酸酐(ASA)改性瓜尔胶。瓜尔胶与ASA反应的最佳条件为:瓜尔胶原粉、ASA质量比7:1,反应温度60℃,反应时间10h,碳酸氢钠质量分数0.4%。0.4%的ASA改性瓜尔胶水溶液的表面张力为35.29mN/m。用过硫酸铵破胶后破胶液的表面张力为29.65mN/m,煤油/冻胶破胶液的界面张力为2.27mN/m,残渣含量为300mg/L。与瓜尔胶原粉相比,改性瓜尔胶制备冻胶的耐温性、耐剪切性提高。在低剪切速率或温度较低时,改性瓜尔胶黏度降低,有利于减少流体在管道中流动的摩阻;而在高剪切速率或温度较高时,改性瓜尔胶黏度增加,有利于后期的携沙造缝。图8表1参13

  4. O Tema da Cidadania

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    Adriano Moreira

    2009-11-01

    Full Text Available Neste artigo tentaremos evidenciar a natureza pelo menos tripartida da cidadania que responde ao incontroladoglobalismo: uma que se confunde com os direitos humanos, exigentes querem seja o Estado o seu interlocutor,quer não exista tal interlocutor; outra que se insere na fenomenologia dos grandes espaços em formação, de que aUnião Europeia é exemplo, e a que o projecto da Constituição Europeia, agora em recolhimento de meditação, jáoferece o apoio de uma definição específica de direitos; e finalmente, a cidadania que diz respeito à relação com oEstado soberano em crise de redefinição, sobretudo, pelo que nos interessa, no espaço europeu.

  5. Fisiopatologia da asma grave

    OpenAIRE

    Todo-Bom, Ana; Mota-Pinto, Anabela

    2006-01-01

    Não tem resumo. Transcreve-se o primeiro parágrafo: A história natural da asma e os condicionalismos de uma evolução para formas moderadas ou graves não está completamente estabelecida. Contudo, quer os factores genéticos quer os factores ambientais, serão determinantes na fisiopatologia e no prognóstico da doença. A asma é, por definição, uma doença inflamatória crónica das vias aéreas caracterizada por uma obstrução brônquica generalizada mas variável que é, pelo menos parcialmente, reve...

  6. [da Vinci surgical system].

    Science.gov (United States)

    Watanabe, Gou; Ishikawa, Norihiro

    2014-07-01

    The da Vinci surgical system was developed by Intuitive Surgical Inc. in the United States as an endoscopic surgical device to assist remote control surgeries. In 1998, the Da Vinci system was first used for cardiothoracic procedures. Currently a combination of robot-assisted internal thoracic artery harvest together with coronary artery bypass grafting (CABG) through a mini-incision (ThoraCAB) or totally endoscopic procedures including anastomoses under robotic assistance (TECAB) are being conducted for the treatment of coronary artery diseases. With the recent advances in catheter interventions, hybrid procedures combining catheter intervention with ThoraCAB or TECAB are anticipated in the future.On the other hand, with the decrease in number of coronary artery bypass surgeries, the share of valvular surgeries is expected to increase in the future. Among them, mitral valvuloplasty for mitral regurgitation is anticipated to be conducted mainly by low-invasive procedures, represented by minimally invasive cardiac surgery( MICS) and robot-assisted surgery. Apart from the intrinsic good surgical view, robotic-assisted systems offer additional advantages of the availability of an amplified view and the easy to observe the mitral valve in the physiological position. Thus, robotic surgical surgeries that make complicated procedures easier are expected to accomplish further developments in the future. Furthermore, while the number of surgeries for atrial septal defects has decreased dramatically following the widespread use of Amplatzer septal occluder, robotic surgery may become a good indication for cases in which the Amplatzer device is not indicated. In Japan, clinical trial of the da Vinci robotic system for heart surgeries has been completed. Statutory approval of the da Vinci system for mitral regurgitation and atrial septal defects is anticipated in the next few years.

  7. 瓜尔豆胶、汉生胶、褐藻酸钠复合耐盐增稠剂的流变性研究%Rheological Study on the Complex Salt-Tolerant Thickener of Guar Gum,Xanthan Gum and Sodium Alginate

    Institute of Scientific and Technical Information of China (English)

    徐粉燕; 刘昌辉; 彭传丰

    2011-01-01

    The rheology of the complex of salt-tolerant thickener guar gum,xanthan gum and sodium alginate are studied.The results show that the optimal proportion of guar gum,xanthan gum and sodium alginate is 4:5:1;the best heating temperature of the complex of salt-tolerant thickener is in the range of 70~80 ℃.The optimal heating time is 1.0~2.0 h and pH 4~10;the addition amount of NaCl can be up to 50% and the change of frost thawing has little impact on the viscosity;complex salt-tolerant thickener is of better salt-tolerance.%本研究对瓜尔豆胶、汉生胶、褐藻酸钠的最佳配比及其复合耐盐增稠剂体系的流变性进行了研究。实验结果表明,瓜尔豆胶、汉生胶、褐藻酸钠的最佳配比为4:5:1,复合耐盐增稠剂体系的最佳加热温度为70~80℃,最佳加热时间为1.0~2.0h;pH 4~10;NaCl添加量可高达50%;冻融变化对其粘度影响较小;复合耐盐增稠剂具有较好的耐盐稳定性。

  8. O paradoxo da legitimidade a partir da legalidade segundo Habermas

    Directory of Open Access Journals (Sweden)

    Aylton Barbieri Durão

    2010-12-01

    Full Text Available http://dx.doi.org/10.5007/1677-2954.2008v7n2p233A autonomia jurídica surge da conexão co-originária entre a autnomia privada dos indivíduos e a autonomia pública dos cidadãos, a qual, contudo, ficou velada ao longo da história da filosofia política e jurídica por causa da herança metafísica do direito natural racional e da filosofia da consciência que gerou uma relação de competição entre os direitos humanos e a vontade soberana do povo. Por causa desta conexão entre a autonomia privada e pública, o processo democrática de produção de normas jurídicas apresenta um aparente paradoxo porque os cidadãos tanto podem aprovar as normas motivados pela busca do êxito da racionalidade estratégica como orientados pelo reconhecimento de sua validade através da racionalidade comunicativa, o qual se dissolve, contudo, quando se considera a democracia como um processo aberto para a solidariedade dos cidadãos no mundo da vida.

  9. O Cognitivismo e o problema da Cientificidade da Psicologia

    OpenAIRE

    Arja Castañon, Gustavo

    2010-01-01

    Este artigo trata do problema do estatuto científico da psicologia. Seu objetivo é avaliar em que medida o cognitivismo solucionou objeções históricas levantadas contra a possibilidade de uma psicologia científica. Com base em avaliação de textos clássicos da “revolução cognitiva”, se conclui que esta abordagem apresentou um projeto filosófico de ciência psicológica que resolveu a maior parte dos problemas ontológicos e epistemológicos endêmicos da disciplina, como o da natureza inquantificáv...

  10. A Utopia da Paz Universal

    Directory of Open Access Journals (Sweden)

    Daniel Serrão

    2009-11-01

    Full Text Available Como o Homem atingiu a fase da cultura exterior simbólica em que se encontra actualmente. Apresentaçãosucinta da teoria dos patamares evolutivos de Merlin Donald. O paradigma "popperiano" da investigaçãocientífica moderna: verificar ou falsificar hipóteses. O caso típico da teoria darwiniana da evolução das espéciesvivas. A Bioética como diálogo de saberes em ordem à criação de uma nova sabedoria (wisdom. Apresentação doconceito de Van Rensselaer Potter. O "credo" de Potter e a utopia da paz universal.

  11. Custos da qualidade

    Directory of Open Access Journals (Sweden)

    Gilberto Caetano

    2009-01-01

    Full Text Available Este artigo pretende demonstrar através de uma síntese histórico-conceitual , a evolução da importância do sistema de qualidade, bem como a sua mensuração no processo de tomada de decisão das organizações frente à competitividade estabelecida no contexto da globalização. Assim, procura dar ênfase à ação planejada no sentido de reduzir ou eliminar falhas e defeitos nos vários processos, com vistas a agregar valor ao cliente e ao mesmo tempo reduzir os custos da não-conformidade. Palavras-chave: Custo, qualidade, satisfação, inspeção, controle, requisito, conformidade, não-conformidade, mensuração, processo, prevenção, problema e avaliação. Abstract This article intends to demonstrate through a historical-conceptual synthesis, the evolution of the importance of the quality system, as well as your measurement the process of decision making of the organizations front to the established competitiveness in the context of the globalization. Like this, it tries to give emphasis to the action drifted in the sense of to reduce or to eliminate flaws and defects in the several processes, with views to join value to the customer and at the same time to reduce the costs of the no-conformity. Key-words: Cost, quality, satisfaction, inspection, control, requirement, conformity, no-conformity, measurement, process, prevention, problem and evaluation.

  12. Pioneirismo da associacao brasileira de enfermagem no desenvolvimento da pesquisa: da revista ao centro de pesquisa

    Directory of Open Access Journals (Sweden)

    Lais de Araujo Pereira

    2013-09-01

    Full Text Available O presente estudo tem como objetivo analisar as primeiras iniciativas da Associação Brasileira de Enfermagem para o desenvolvimento da pesquisa em enfermagem. Com um recorte temporal que engloba o período de 1932 a 1971, ano de criação da Revista Brasileira de Enfermagem à criação do Centro de Estudos e Pesquisas, da Associação Brasileira de Enfermagem. As fontes utilizadas foram documentos escritos localizados no Centro de Documentação da Escola de Enfermagem Anna Nery da Universidade Federal do Rio de Janeiro e no Centro de Memória da Associação Brasileira de Enfermagem, além de edições da revista localizadas na Biblioteca Setorial da Pós-Graduação da Escola de Enfermagem Anna Nery. Percebe-se, nesta análise, que os empreendimentos realizados por essa entidade representaram um verdadeiro espaço de investigação e de formação de enfermeiros pesquisadores no Brasil.

  13. Pensamento da America

    OpenAIRE

    2013-01-01

    Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Filosofia e Ciências Humanas, Programa de Pós-Graduação em História, Florianópolis, 2013. Esta dissertação objetivou investigar a atividade editorial de Rui Ribeiro Couto e Renato Costa Almeida enquanto estes intelectuais estiveram à frente do Pensamento da America, uma publicação mensal vinculada ao A Manhã, jornal porta voz do Estado Novo. Este suplemento panamericano veio a público entre 1941 e 1949, no entanto a...

  14. Propriedades antioxidantes da melatonina

    OpenAIRE

    Teixeira,Adriana

    2003-01-01

    Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Biológicas. Programa de Pós-Graduação em Neurociências. Foram investigadas as ações da melatonina (MEL) contra a lipoperoxidação (LPO) induzida por hidroxil (OH), ascorbil (Asc) e peroxinitrito (ONOO-) em diversos modelos de membranas como lipossomas de fosfatidilcolina (LipPC) e asolecitina (LipASO), microssomas de cérebro (MicC) e fígado (MicF) e homogeneizado de cérebro (HC); e seu efeito contra enzimas ...

  15. A moral da infidelidade

    Directory of Open Access Journals (Sweden)

    Bundt, Roger

    2007-01-01

    Full Text Available Através das representações da infidelidade conjugal encontradas em três filmes do diretor Adrian Lyne realizados nas décadas de 1980, 1990 e 2000 (Atração Fatal, Proposta Indecente e Infidelidade, busca- se entender as idéias trabalhadas em cada obra, as maneiras de representar a mulher, a família, a relação amorosa e a monogamia, a partir das noções de dever e moral trabalhadas por Gilles Lipovetsky

  16. A moralidade da nanotecnologia

    OpenAIRE

    2012-01-01

    A nanotecnologia é um conjunto formado por saberes, técnicas e práticas que estudam e exploram as novas propriedades dos materiais, quando manipulados em níveis atômicos e moleculares. A possibilidade técnica de organizar e controlar a matéria, desde suas menores dimensões e unidades, pode implicar profundas transformações no processo industrial de produção e ter consequências, moralmente significativas, sobre as inter-relações humanas, a organização da conjuntura social vigente e o próprio f...

  17. Aspectos moleculares da anemia falciforme

    Directory of Open Access Journals (Sweden)

    Galiza Neto Gentil Claudino de

    2003-01-01

    Full Text Available No presente artigo abordaram-se vários aspectos relacionados à natureza molecular da anemia falciforme, desordem hematológica de caráter hereditário que acomete expressivo número de indivíduos em várias regiões do mundo. As pesquisas realizadas em torno desta patologia da hemácia, ao longo de quase um século, a partir de 1910, cooperaram para a criação de um novo e importante segmento da ciência, denominado biologia molecular. A descoberta dos polimorfismos da mutação (GAT->GTG no gene que codifica a cadeia beta da hemoglobina, originando diferentes haplótipos da doença, permitiu um melhor e mais amplo conhecimento em torno da heterogeneidade clínica nos pacientes falcêmicos. Analisando a hemoglobina na sua estrutura normal e mutante, sua produção e evolução, pode-se ter um entendimento mais completo da fisiopatologia desta doença e da sua complexidade clínica.

  18. Fractais : da geometria à videoarte

    OpenAIRE

    2013-01-01

    A descoberta da geometria fractal é datada de meados do séc. XX. É conhecida como a geometria da natureza já que permite descrever muitos fenómenos naturais que apresentam irregularidades que são impossíveis de descrever através dos princípios da geometria tradicional. O aparecimento de novas tecnologias digitais veio alterar o modo como a arte é encarada. Este trabalho pretende demonstrar possibilidades de integração da geometria fractal e a Teoria do Caos na criação de videoarte, b...

  19. Fisiopatogênese da dor

    Directory of Open Access Journals (Sweden)

    Miguel R. Covian

    1965-09-01

    Full Text Available O estudo da dor é um capítulo do estudo das bases neurofisiológicas da sensação, pois a dor nada mais é que uma sensação de conteúdo desagradável originada por estímulos nocivos. Enquanto a função das outras modalidades sensoriais é informativa ou gnósica, a dor é de proteção. O estudo da fisiología da dor compreende o estudo dos receptores, dos estímulos, das vias, das estruturas do sistema nervoso central que partici- pam da fisiología da dor, da percepção dolorosa e das reações motoras e neurovegetativas. São analisados os receptores e as vias e discutidas sua especificidade, assim como a transmissão da dor rápida e lenta por vias nervosas diferentes até o córtex cerebral. É comentada a influência da atenção na intensidade da percepção dolorosa e, com base em estudos experimentais, é considerado que o circuito retículo-córtico-reticular seja indispensável para a percepção da dor. No tocante à patologia da dor é examinada a insensibilidade congênita à dor, sendo admitida a hipótese de que em algumas sinapses é modificado o esquema de impulsos que darão lugar à sensação dolorosa. É destacado o papel do lobo frontal como parte de um mecanismo pòtenciador que condiciona o sofrimento geral do paciente. A dor referida é explicada pela teoria da "convergência-projeção" de fibras viscerais com fibras cutâneas dolorosas sôbre o mesmo neurônio em algun ponto da via sensitiva. O resultado da hipofisectomia trazendo uma diminuição ou anulação da dor no câncer do seio abre debates em tôrno do papel dos hormônios na percepção dolorosa.

  20. Tumores cartilaginosos da laringe

    Directory of Open Access Journals (Sweden)

    Thomé Robert

    2001-01-01

    Full Text Available Introdução: Os tumores cartilaginosos da laringe são raros, sendo a cartilagem cricóide a mais acometida. A raridade desses tumores tem como conseqüência experiência limitada e, portanto, o conhecimento a respeito destas neoplasias apresenta pontos obscuros. Objetivo: Apresentar os resultados cirúrgicos bem como o seguimento a longo prazo de 6 pacientes com tumores cartilaginosos da laringe, 4 condrossarcomas de baixa malignidade e 2 condromas. Forma de estudo: Retrospectivo não randomizado. Material e método: Cinco dos tumores acometiam a cartilagem cricóide e 1 a tireóide. Os pacientes foram submetidos a laringectomia parcial (4 e total (2, com seguimento de 6 a 30 anos (média-19,5 anos. Resultados: Nenhum dos pacientes apresentou metástase ou morte relacionada ao tumor. A sobrevida alcançada por 5 anos foi de 100% e a por 20 anos, 67%, sendo a comorbidade responsável por tal decréscimo. Conclusões: Nossos resultados reforçam o conceito de que a laringectomia conservadora seja a modalidade ideal de tratamento, reservando a ressecção total para tumores extensos ou casos de recorrência. Há indícios de que 5 anos pode não ser tempo suficiente para observar recorrência no condrossarcoma de baixo grau de malignidade.

  1. Dos Males da Medida

    Directory of Open Access Journals (Sweden)

    Schwarcz Lilia Moritz

    1997-01-01

    Full Text Available Esse artigo tem como objeto a difícil percepção da "diferença". Tema polêmico, o debate sobre as variedades culturais foi transformado, em meados do século XIX, em uma questão racial e, nesse sentido, vinculado às regularidades da biologia. Tecendo comparações entre os teóricos raciais brasileiros e os impasses mais contemporâneos, sobre a aferição de inteligência e capacidade, esse ensaio pretende provocar. Em pauta estarão as contradições que têm se destacado, mais recentemente, quando se opõem de um lado as etnicidades locais, de outro a tão propalada globalização. Tal qual dois lados de uma mesma moeda, a afirmação de identidades tem se mostrado tão evidente como o próprio estreitamento das relações internacionais. Mudam os termos do debate - de raça, para etnia -, mas, de alguma maneira, continuamos presos a uma lógica positiva de estabelecimento de hierarquias ontológicas.

  2. Os usos da diversidade

    Directory of Open Access Journals (Sweden)

    Clifford Geertz

    1999-05-01

    Full Text Available Resumo Ao discorrer sobre o “Futuro do Etnocentrismo”, este artigo parte da premissa de que a globalização, apesar de ter – em muitos casos – diminuído as diferenças entre povos, não tem amenizado os preconceitos e as formas de discriminação que ocorrem em nome dessas diferenças. Ele resgata a importância do antropólogo neste cenário lembrando que a diversidade cultural faz parte da sociedade complexa, remetendo-se não apenas a grupos étnicos ou nacionais bem delimitados, mas também a diferenças de geração, gênero, sexo e classe, entre outros. Neste contexto, a tolerância passiva de modos distantes de vida assim como a aceitação pragmática de nosso próprio paroquialismo são atitudes não somente intelectualmente desonestas mas também moralmente repreensíveis. É no encontro incômodo de subjetividades variantes na sua própria sociedade que o antropólogo define seu lugar.

  3. A morte da bailarina

    Directory of Open Access Journals (Sweden)

    Nancy Mangabeira Unger

    2010-04-01

    Full Text Available A história do Ocidente pode ser lida de acordo com o sentido da palavra grega hybris: transgressão, presunção, desmesura. Hoje, vivemos o ápice de um percurso marcado pela desejo de tudo dominar. Por sua extrema gravidade, a crise contemporânea nos coloca diante da responsabilidade de questionar a própria dimensão na qual pensamos, e a maneira em que compreendemos nossa identidade enquanto humanos e nosso lugar na totalidade do real.Palavras-chave: civilização ocidental; crise; hybris; questionamento. AbstractThe history of the West can be read according to the meaning of the greek word hybris: transgression, arrogance, loss of measure. We presently live the pinnacle of a course marked by the desire to dominate all beings.  The extreme gravity of  contemporary crisis confronts us with the responsibility of questioning the very dimension in which we think, as well as the manner in which we understand our identity as human beings and our place in the totality of being.Key words: western civilization; crisis; hybris; questioning. 

  4. Fisiologia da caquexia

    OpenAIRE

    Gonçalves, Catarina Vicente

    2014-01-01

    Dissertação para obtenção do grau de Mestre no Instituto Superior de Ciências da Saúde Egas Moniz A caquexia é uma síndrome de desnutrição multifatorial que se caracteriza por uma perda de peso e perda de massa muscular. Esta síndrome parte de uma doença subjacente e pode estar presente em várias doenças crónicas como por exemplo HIV, doença renal crónica, DPOC, doença hepática crónica, insuficiência cardíaca congénita e cancro. Com este trabalho, pretendeu-se entender a definição de ca...

  5. Em favor da talassografia

    Directory of Open Access Journals (Sweden)

    Jean-Louis Boudou

    2001-01-01

    Full Text Available A Talassografia (“descrição do mar” interessa-sepelos impactos físicos, biológicos, ecológicos... culturais da violenta antropização dos ambientes costeiros (oceânicos e continentais, caracterizados pelaexigüidade, vulnerabilidade, fragilidade e plasticidade. Como o Brasil é um “país marítimo”, os geó-grafos (os talassógrafos brasileiros são convidadosa intensificar suas pesquisas nas áreas costeiras e acriar novas estruturas para divulgá-las: Revista, Encontros, Associação, Pós-Graduação... tudo em prolda talassografia.

  6. Fisiologia da caquexia

    OpenAIRE

    Gonçalves, Catarina Vicente

    2014-01-01

    Dissertação para obtenção do grau de Mestre no Instituto Superior de Ciências da Saúde Egas Moniz A caquexia é uma síndrome de desnutrição multifatorial que se caracteriza por uma perda de peso e perda de massa muscular. Esta síndrome parte de uma doença subjacente e pode estar presente em várias doenças crónicas como por exemplo HIV, doença renal crónica, DPOC, doença hepática crónica, insuficiência cardíaca congénita e cancro. Com este trabalho, pretendeu-se entender a definição de ca...

  7. Berengario da Carpi.

    Science.gov (United States)

    De Santo, N G; Bisaccia, C; De Santo, L S; De Santo, R M; Di Leo, V A; Papalia, T; Cirillo, M; Touwaide, A

    1999-01-01

    Berengario da Carpi was magister of anatomy and surgery at the University of Bologna from 1502 to 1527. Eustachio and Falloppia defined him as 'the restaurator of anatomy'. He was a great surgeon, anatomist and physician of illustrious patients including Lorenzo II dei Medici, Giovanni dalle Bande Nere, Galeazzo Pallavicini, Cardinal Colonna, and Alessandro Soderini. He had strong links to the intellectuals of his time (Forni, Bonamici, Manuzio, Pomponazzi) as well as with the Medici family. He was respected by the Popes Julius II, Leo X and Clement VII. His main contributions are the Isogogae Breves, De Fractura calvae sive cranei, and the illustrated Commentaria on the Anatomy of Mondino de Liucci, a textbook utilized for more than 200 years, which Berengario aimed to restore to its initial text. The Commentaria constitutes the material for the last part of this paper which concludes with a personal translation of some passages on 'The kidney', where the author gives poignant examples of experimental ingenuity.

  8. 徐淑臻韩雪田俊楠吴寨陈忠秀%Mechanism behind the Inhibition of Sweetness Intensity of Aspartame by Guar Gum and Locust Bean Gum

    Institute of Scientific and Technical Information of China (English)

    徐淑臻; 韩雪; 田俊楠; 吴寨; 陈忠秀

    2014-01-01

    s: Current research on the effects of macromolecular hydrocol oids on sweetness is mainly focused on the properties of hydrocol oids and their texture-taste interactions. In this paper, the influence of two kinds of nonionic food hydrocol oids, Guar gum (GG) and Locust bean gum (LBG) on the taste of aspartame (APM) was studied. Sensory evaluation revealed high concentrations of GG and LBG significantly inhibited the sweetness intensity of APM, especial y when their concentrations were higher than C* (coil overlap concentration). The mechanism of this phenomenon was investigated using an artificial taste receptor model and isothermal titration calorimetry. The association constant for APM, determined by the artificial taste receptor model, decreased in the presence of GG and LBG. More bound water was found in GG and LBG with an increase in the hydrocol oid concentration, especial y at higher than C*. Additionally, water diffusion was hampered and this contributed to the lower sweetness intensity. We thus determined the influence of the hydrocol oid on the binding of sweeteners with the receptor, its water mobility as wel as its diffusion behavior in the hydrocol oidal texture. The information obtained enables an understanding of the mechanism behind the effects of macromolecular hydrocol oids on taste.%目前大分子水溶胶对于味觉物质的影响机制研究主要集中于胶体自身的性质以及胶体结构与味物质的相互作用。本文选择了食品中常用的瓜儿豆胶(GG)和刺槐豆胶(LBG),研究了这两种非离子水溶胶对甜味剂阿斯巴甜(APM)感官甜度的影响,并探索了其中的物理化学机制。感官实验结果表明,高浓度的瓜儿豆胶和刺槐豆胶对阿斯巴甜的甜度有抑制作用,且随着水溶胶浓度的增高,达到高分子临界交叠浓度C*后,抑制作用更明显。基于人工受体模型,利用等温滴定量热(ITC)技术发现,两种水溶胶存在条件下阿斯巴甜与

  9. Estudo das características de adsorção de água e da estabilidade das microcápsulas de óleo essencial de laranja na seleção de material de parede Water adsorption characteristics and stability of orange essential oil microcapsules in the wall material selection

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    D. P. R. ASCHERI

    1999-12-01

    Full Text Available Este trabalho consistiu no estudo e comparação das características de adsorção de água de três amostras de microcápsulas de óleo essencial de laranja, obtidas pela secagem por atomização de três diferentes emulsões preparadas pela adição de óleo essencial de laranja (oel, a uma solução aquosa de material de parede (mp constituída de capsul (5,0, 0,0 e 10,0%, goma arábica (5,0, 10,0 e 0,0% sendo constante para as três emulsões a maltodextrina (36,0%, água (44,0% e óleo essencial (10,0%. A microencapsulação foi realizada a 220 e 110° C de ar de entrada e saída do secador usando um atomizador rotativo a 20.000rpm. Com base à determinação das isotermas de adsorção de água a 30, 40 e 50° C e usando o modelo de GAB para ajustar os pontos experimentais foram avaliadas as características das isotermas, a estabilidade e área superficial de adsorção de água das diferentes amostras de microcápsulas obtidas. Os resultados indicaram ser importante o estudo das características de adsorção de água para estimar a estabilidade das microcápsulas de oel e a comparação destas mostrou que as microcápsulas obtidas pela secagem por atomização da emulsão preparada com 5,0% de capsul e 5,0% de goma arábica apresentaram o melhor resultado.This work consisted of the study and comparison of the water adsorption characteristics of three samples orange essential oil microcapsules obtained by spray drying of three different emulsions prepared by the addition of orange essential oil (oel to an aqueous solution of wall material (mp constituted of capsul (5.0, 0.0 and 10.0%, arabic gum (5.0, 10.0 and 0.0% being constant for the three emulsions the maltodextrin (36.0%, water (44.0% and essential oil (10.0%. The microencapsulation was accomplished to 220 and 110°C of entrance air and exit of the dryer using a wheel atomizer to 20,000rpm. With base to the determination of the water adsorption isotherms to 30, 40 and 50°C and

  10. A influência da Internet no processo ensino-aprendizagem da leitura e da escrita

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    Evanice Ramos Lima Barreto

    2010-03-01

    Full Text Available

    A Internet constitui um dos grandes avanços da comunicação humana. Através dela, é possível o contato com uma infinidade de informações, veiculadas pelos mais diversos gêneros de texto. Por isso, sendo um dos meios de comunicação que mais se expandiu no mundo, a Internet se apresenta como uma ferramenta indispensável no ensino-aprendizagem da leitura e da escrita. Partindo desse pressuposto, o presente trabalho pretende apresentar os resultados de um estudo que tem por objetivo investigar, à luz dos pressupostos empreendidos por Soares (1998 e Dionísio (2005, qual o “lugar” da Internet no processo de ensino-aprendizagem da leitura e da escrita, bem como até que ponto ela interfere de forma positiva e/ou negativa nesse processo. Para tanto, foram aplicados questionários a professores e alunos do Ensino Médio. A partir da análise dos dados, pretende-se verificar como a sobrecarga de informações, bem como o uso inadequado da Internet podem trazer implicações para o desenvolvimento dessas atividades.

  11. Dimensão da maturidade à luz da logoterapia

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    Libardi, Tadeu Antonio

    2008-01-01

    Full Text Available O artigo aborda o tema da maturidade humana à luz da logoterapia, fundada por Viktor Emil Frankl. Nos dias de hoje, existe a frustração existencial, não mais a sexual, como analisada por Freud. Cada ser humano, como pessoa livre e responsável e tendo como meta a busca da maturidade, vai percorrendo seu próprio caminho, que o leva à ceitação de si, de seus limites e potencialidades e ao relacionamento social e religioso, capacitando-o ao confronto com o sofrimento humano

  12. Mito da guerra nos Estados Unidos

    OpenAIRE

    Spini, Ana Paula; UFU

    2011-01-01

    Este artigo tem como objetivo compreender aspectos do mito da guerra nos Estados Unidos, em uma abordagem que prioriza as dissensões internas acerca da legitimidade de uma guerra e os dispositivos midiáticos de criação do consenso nacional. Procura-se, assim, demonstrar que o mito da guerra é constantemente reformulado à luz da conjuntura internacional, da prática da guerra, da propaganda e da resistência interna às intervenções militares. Palavras-Chave: Guerra; Estados Unidos; Mídia....

  13. Controle da ferrugem e da broca-dos-ramos da figueira com diferentes fungicidas e inseticidas

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    Éder Júnior Mezzalira

    2015-02-01

    Full Text Available Temperaturas e precipitações elevadas favorecem a incidência da ferrugem (Cerotelium fici(Cast. e da broca-dos-ramos (Azochis gripusalis (Walker, 1859 (Lepidoptera: Pyralidae, limitando a produção comercial de figos. O objetivo deste trabalho foi comparar a eficiência de fungicidas e inseticidas alternativos em relação à de produtos convencionais registrados para a cultura. Foram realizados dois experimentos, no delineamento de blocos inteiramente casualizados, com quatro repetições, no setor de fruticultura da Universidade Tecnológica Federal do Paraná, Campus Dois Vizinhos. Para controle da ferrugem, foram utilizados, em 100 L de água, azoxistrobin (10 g, calda bordalesa (1.500 g de cal virgem + 1.500 g de sulfato de cobre e testemunha (água. No controle da broca-dos-ramos utilizaram-se, em 100 L de água, azadiractina (1.000 mL P.C., alho (Allium sativumL. (100 mL P.C., cinza (20.000 g, extrato de fumo (nicotina (10.000 mL do preparado, deltametrina (50 mL P.C., Bacillus thuringiensisBerliner (100 g P.C., rotenona (1.000 mL P.C., sabão de coco (1.000 g e testemunha (água. A calda bordalesa foi o tratamento mais efetivo no controle da ferrugem, promovendo aumento da produtividade e da qualidade dos frutos. A deltametrina promoveu o melhor controle da broca-dos-ramos da figueira. Entre os produtos alternativos testados, o alho foi o mais efetivo no controle dessa praga.

  14. Dificuldades da aprendizagem na leitura

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    Solange Oliveira Nascimento

    2011-07-01

    Full Text Available Este presente artigo propôs verificar os fatores que influenciam no desenvolvimento da aprendizagem na leitura dos alunos da 4º ano no Ensino Fundamental na Escola Municipal Armando Dias no município de Sinop/MT, cujo tema é dificuldade da aprendizagem na leitura. O objetivo do trabalho foi investigar as relações interpessoais em sala de aula e de que forma a professora introduz a leitura nos conteúdos dados aos alunos. Como fundamentação teórica, recorremos a vários autores, entre eles: Enrique Cártula Fita, Elisabete da Assunção Jóse, Jésus Alonso Tapia, Maria Tereza Coelho e Ruth Caribe da Rocha Drouet. A metodologia usada consistiu na pesquisa qualitativa, no estudo de caso e questionário com perguntas abertas e fechadas aplicadas à professora e três alunos que estão com dificuldades na leitura. Através dos relatos dos sujeitos realizamos um estudo analítico confrontando os dados da pesquisa com os autores principais que fundamentam a mesma. O presente trabalho pretende contribuir e mostrar ao professor em sala de aula a importância de incentivar os alunos a aprenderem a ler com prazer motivando-os a despertar o interesse e gosto pela leitura. Os resultados da investigação revelam que a professora pesquisada está ciente de seu papel e procura meios para enfrentar os problemas existentes em sala de aula, em especial às dificuldades da aprendizagem na leitura e os alunos percebem a importância da leitura e tem vontade em avançar nesse aprendizado.Palavras-chave: educação; dificuldades na aprendizagem. professor; aluno; sala de aula.

  15. JORNALISMO AUDIOVISUAL: DA TELA DA TV PARA OUTRAS TELAS

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    Mayra Ferreira

    2012-12-01

    Full Text Available O presente trabalho é fruto de uma pesquisa em desenvolvimento em parceria com a TV Unesp, emissora universitária vinculada à Universidade Estadual Paulista Júlio de Mesquita, campus de Bauru/SP e que tem por objetivo identificar os pontos convergentes e divergentes na produção de conteúdo audiovisual informativo para a TV aberta e demais plataformas digitais e móveis. O texto em questão é a conclusão da primeira etapa da pesquisa que se pautou por identificar os pressupostos básicos que deverão nortear os conteúdos que serão produzidos posteriormente e veiculados pela emissora no decorrer da pesquisa. Foram analisadas as características do jornalismo audiovisual online e o modelo de negócios da TV aberta em contraste com o modelo de negócios presente na Internet.

  16. Dificuldades da aprendizagem na leitura

    OpenAIRE

    Nascimento, Solange Oliveira; Trugillo, Edneuza Alves

    2011-01-01

    Este presente artigo propôs verificar os fatores que influenciam no desenvolvimento da aprendizagem na leitura dos alunos da 4º ano no Ensino Fundamental na Escola Municipal Armando Dias no município de Sinop/MT, cujo tema é dificuldade da aprendizagem na leitura. O objetivo do trabalho foi investigar as relações interpessoais em sala de aula e de que forma a professora introduz a leitura nos conteúdos dados aos alunos. Como fundamentação teórica, recorremos a vários autores, entre eles: Enri...

  17. Controlo da Qualidade em Hemoglobinopatias

    OpenAIRE

    Miranda, Armandina

    2015-01-01

    Experiência do Controlo da qualidade em Hemoglobinopatias, pelo Grupo de Trabalho de Hematologia do Programa Nacional de Avaliação Externa da Qualidade (PNAEQ), INSA. As Hemoglobinopatias são doenças monogénicas hereditárias de transmissão autossómica recessiva resultantes de mutações que afetam os genes responsáveis pela síntese das cadeias de globina da hemoglobina, ou as suas regiões regulatórias.

  18. ESTUDO DA PASTEURIZAÇÃO DA POLPA DE GRAVIOLA

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    C. K. B. TEIXEIRA

    2009-01-01

    Full Text Available

    Estudou-se a pasteurização da polpa de graviola (Annona muricata L., visando estabelecer condições simples e eficientes para sua conservação. Foram realizadas avaliações microbiológica, enzimática e de cor da polpa, para identificar parâmetros a serem utilizados no acompanhamento da pasteurização. O produto foi submetido a tratamento térmico, em copos de inox, em diferentes tempos (1 a 300 seg e temperaturas (70°C a 90°C, para identificar o efeito destas variáveis sobre parâmetros de qualidade do produto. Constatou-se que os tratamentos não provocaram variação na atividade da peroxidase, contagem de bactérias, bolores e leveduras e cor da polpa. Em seguida foram realizadas pasteurizações, em escala piloto, a 80°C e 90°C; sendo os produtos estocados a 25°C e avaliados durante 120 dias. A redução da atividade da peroxidase e da concentração de bactérias, bolores e leveduras, a níveis aceitáveis, e a manutenção da cor, demonstraram a eficiência dos processos térmicos. A manutenção destes parâmetros, nos níveis aceitáveis, durante a estocagem, confirmou a aplicabilidade dos processos, sem a necessidade da adição de conservante na polpa. A pasteurização da polpa de graviola a 80°C ou 90°C, mostrou ser um tratamento térmico adequado para a conservação do produto, proporcionando 120 dias de vidade- prateleira à temperatura ambiente ( 25°C.

  19. A INTERPRETAÇÃO DELEUZEANA DA GENEALOGIA DA MORAL

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    Péricles Pereira de Sousa

    2014-12-01

    Full Text Available O texto tem o objetivo de apresentar como o filósofo francês Gilles Deleuze, a partir da obra Nietzsche e a Filosofia, interpreta a Genealogia da Moral, obra escrita pelo filósofo alemão Friedrich Nietzsche, levando em consideração as formas mais gerais do niilismo: ressentimento, má consciência e ideal ascético.

  20. O sentido da espiritualidade na transitoriedade da vida

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    Isabel Cristina de Oliveira Arrieira

    Full Text Available Resumo Objetivo: Compreender o sentido da espiritualidade para a pessoa em cuidados paliativos. Métodos: Abordagem qualitativa, fundamentada na fenomenologia existencialista e referencial de Viktor Frankl. Os participantes foram nove pessoas em cuidados paliativos atendidas no domicílio. Informações coletadas por meio da observação e de entrevista realizadas no período de junho a outubro de 2014, gravadas, transcritas e transformadas em texto interpretado com a abordagem fenomenológica hermenêutica. Resultados: Surgiram as seguintes categorias: sentido de continuidade da vida; sentido de alívio do sofrimento; sentido de naturalidade da morte e sentido de valorização do viver. Conclusão: Para a integralidade da atenção faz-se necessário a inclusão da espiritualidade na prática do cuidado em saúde. A espiritualidade proporciona o encontro existencial entre a pessoa em cuidados paliativos e os profissionais que a cuidam em sua integralidade.

  1. O PROBLEMA DA ORIGEM DA TRAGÉDIA EM NIETZSCHE

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    Rafael Koehler; Rosana Jardim Candeloro

    2012-12-01

    Full Text Available O objetivo deste artigo consiste em analisar como Nietzsche, baseado na filosofia schopenhauriana, resolveu o problema do surgimento da tragédia grega através da elevação dos elementos Apolo e Dionísio a um estatuto ontológico, e como os gregos fizeram isso em seu tempo através da Música, além de revelar como, em Nietzsche, o pensamento de Sócrates surge como o “perverso algoz da arte”.O estudo foi realizado através de uma pesquisa bibliográfica com base nas seguintes obras do filósofo: A visão Dionisíaca de Mundo (uma compilação de duas conferências e um texto não publicado e O nascimento da tragédia no espírito da Música. Na segunda parte, sugere-se como Nietzsche faz esse resgate do trágico em sua época e qual a recepção no século XIX de seu trabalho.

  2. O uso da aromaterapia na melhora da autoestima

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    Juliana Rizzo Gnatta

    2011-10-01

    Full Text Available Os objetivos deste estudo foram verificar se a inalação dos óleos essenciais de rosa e de ylang-ylang alteram a percepção da autoestima e comparar a eficácia dos mesmos. O projeto foi aprovado pelo Comitê de Ética em Pesquisa do Hospital da Universidade de São Paulo. Participaram 43 funcionários dos setores de Higienização e da Central de Materiais e Esterilização durante os meses de maio a julho de 2009. Os sujeitos foram randomizados em três grupos: dois que receberem os óleos essenciais e outro que recebeu placebo (essência de rosa. A avaliação da autoestima foi feita através de uma escala já validada no Brasil, sendo aplicada antes do uso dos aromas, depois de 30 dias de uso e ao completar 60 dias. Dentre os resultados, verificou-se que a amostra era constituída por 88,6% de indivíduos com média e alta autoestima e que os óleos essenciais em questão não alteraram de forma significativa a percepção da autoestima.

  3. SOBRE OS FUNDAMENTOS DA ARQUITETURA DA INFORMAÇÃO

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    Alfram Roberto Rodrigues de Albuquerque

    2011-10-01

    Full Text Available Expõe-se o estado atual da disciplina Arquitetura da Informação quanto a problemática terminológica da definição do campo de estudo, apresentando-se argumentos para uma definição de Arquitetura da Informação de uma forma ampla na qual os usos correntes dessa expressão sejam vistos como especializações. Defende-se uma definição com a utilização de um conjunto de propriedades mínimas cujas interações levam a uma terminologia formal e cuja abstração leva a uma definição formal do conceito que emprega a linguagem de morfismos da Teoria das Categorias. Trata-se de um recorte de alguns dos resultados obtidos na tese de doutoramento de um dos autores, defendida em setembro de 2010. O contexto da pesquisa é exposto e alguns dos resultados obtidos são delineados.

  4. A utilização da teoria da aprendizagem significativa no ensino da Enfermagem

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    Alana Tamar Oliveira de Sousa

    2015-08-01

    Full Text Available RESUMOObjetivo:sintetizar a produção científica acerca da Teoria da Aprendizagem Significativa no processo de ensino-aprendizagem em Enfermagem.Método:revisão integrativa realizada nas bases de dados MEDLINE, LILACS, SciELO, BDENF e CINAHL, com artigos que abordaram a temática ou aspectos da teoria da aprendizagem significativa de David Ausubel. Fizeram parte da amostra dez artigos, sendo seis escritos no idioma português e quatro no inglês, publicados de 1998 a 2013.Resultados:cinco artigos fizeram alusão à Teoria da Aprendizagem Significativa, quatro citaram Ausubel como autor dessa teoria e apenas dois seguiram a estrutura para a aplicação da teoria completamente. Há escassez de estudos sobre o tema e os que o abordam não o correlacionam com a teoria de Ausubel.Conclusão:faz-se necessário romper com a dicotomia entre teoria e prática e promover a articulação dos conteúdos com a ação, introduzindo o aluno como autor de seu próprio conhecimento.

  5. DESENVOLVIMENTO DA PERSONALIDADE DA CRIANÇA: O PAPEL DA EDUCAÇÃO INFANTIL

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    Michelle de Freitas Bissoli

    2014-12-01

    Full Text Available Este trabalho, de cunho teórico-bibliográfico, tem por objetivo trazer à discussão a relação que se estabelece entre a prática pedagógica desenvolvida na Educação Infantil e a formação da personalidade da criança. Tem por fundamentos os pressupostos da Teoria Histórico-Cultural e busca responder, fundamentalmente, às seguintes questões: O que é a personalidade?; Quais são as forças motrizes do seu processo de desenvolvimento nos primeiros anos de vida da criança?; Quais as especificidades do trabalho dos professores da Educação Infantil e como a atividade pedagógica pode contribuir para o desenvolvimento da personalidade infantil? Para tanto, pretendemos refletir sobre alguns princípios essenciais de um trabalho docente capaz de impulsionar o processo formativo integral da criança na Educação Infantil. Consideramos que, com a consolidação de práticas pedagógicas que medeiem as relações entre as crianças e a cultura, é possível organizar atividades que focalizem as diferentes dimensões do desenvolvimento humano e a personalidade.

  6. Atlas nacional da Espanha, demografia

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    Hervé Théry

    2009-03-01

    Full Text Available Calvo Palacios J.L., Pueyo Campos Á. (2008, Atlas nacional de España, Demografía. Madrid: Centro Nacional de Información Geográfica, 386 p. ISBN: 978-8-4416-0685-2.O volume, que faz parte da série Monografias do Atlas Nacional de Espanha, inclui 420 mapas, 91 dos quais apresentam informações por município que dão uma visão global, concisa e muito completa da realidade da população espanhola e da sua evolução (em alguns casos analisada desde 1857. Seus diretores científicos são José Luis Cal...

  7. A subjetividade fora da mente

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    Alexandre Simões

    2011-08-01

    Full Text Available O artigo contextualiza uma tradição que se apresenta de maneira recorrente nas práticas clínicas da psicologia e da saúde mental: o Mentalismo. O Mentalismo pressupõe uma concepção interiorizada do sujeito em prol de modelos instrumentais de clínica. A partir da crítica ao Mentalismo, os autores examinam outras possibilidades de se lidar não mais com o sujeito essencializado, porém, com os complexos processos de subjetivação. Esta é uma perspectiva clínica que recorrendo a Deleuze, Guattari e à Filosofia da Diferença oferece estratégias mais condizentes com a complexidade do mundo contemporâneo, introduzindo debates éticos, políticos e estéticos na dimensão psíquica.

  8. A teoria da gastrea de Ernst Haeckel

    OpenAIRE

    Guilherme Francisco Santos

    2011-01-01

    O objetivo principal de nosso trabalho é descrever e analisar criticamente o núcleo da teoria da gastrea de Ernst Haeckel. Ele gira em torno de duas noções principais: forma gastrular e metazoário. A teoria da gastrea é um conjunto de formulações que visa estabelecer uma definição de metazoário a partir da noção de forma gastrular. O argumento central da teoria da gastrea articula essas duas noções para organizar a partir de estudos de embriologia comparativa uma visão geral da história evolu...

  9. Desafios da leitura e da escrita em meio digital

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    Adair de Aguiar Neitzel

    2015-04-01

    Full Text Available Este artigo trata das estratégias de ensino no campo da leitura literária que os licenciandos de Letras promoveram no decorrer do Programa Docência na Educação Básica/PIBID/UNIVALI. Foram analisadas as concepções que subjazem essas estratégias e como elas colaboram para a formação de leitores no ensino médio. Esta investigação, de caráter qualitativo, utilizou como instrumentos de coleta de dados os portfólios redigidos pelos licenciandos de Letras, bolsistas do PIBID, disponíveis no ambiente virtual da instituição, e entrevistas com os alunos do ensino médio que participaram da pesquisa. Os resultados apontam que, por meio da leitura e da produção de contos multimídias, os alunos foram capazes de fazer relações com outros textos; ampliar o diálogo sobre a obra lida; colocar a pesquisa no centro do processo; fazer uso da autonomia na escolha do material; participar de um processo criativo; trabalhar em equipe; aprender a importância da revisão na produção de textos; negociar saberes. Ao trabalhar-se com a literatura de forma a resguardar sua função estética, os estudantes mudaram sua visão sobre o texto literário, passando a compartilhá-lo com os pares e a reconhecer as literariedades do texto e as sutilezas das construções literárias.

  10. GRAU DA PRÁXIS DA GESTÃO DA RESPONSABILIDADE AMBIENTAL PRATICADA POR USINAS SUCROALCOOLEIRAS

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    Renata Longo

    2014-12-01

    gerencial (PCDA foi o Action que apresentou maior grau de aderência. Há uma concordância acentuada às características fundamentais do ciclo gerencial na Gestão da Responsabilidade Socioambiental.

  11. Sorption of water vapor, hydration, and viscosity of carboxymethylhydroxypropyl guar, diutan, and xanthan gums, and their molecular association with and without salts (NaCl, CaCl2, HCOOK, CH3COONa, (NH4)2SO4 and MgSO4) in aqueous solution.

    Science.gov (United States)

    Banerjee, Paltu; Mukherjee, Indrajyoti; Bhattacharya, Subhash; Datta, Sidhhartha; Moulik, Satya P; Sarkar, Diptabhas

    2009-10-06

    Gums are routinely used in food industry, pharmacy and oil recovery process. In these uses, the hydrocolloids very often encounter interactions with salts at moderate to high temperature. Since they are normally employed in the form of solution and gel, their viscous or fluidity properties need detailed investigation. In the present work, properties such as water vapor adsorption of finely powdered carboxymethylhydroxypropyl derivatized guar (CMHPG) as well as xanthan (Xn) and diutan (Dn) gums, their hydration in solution, their viscosity behaviors, and salt effects on fluidity have been studied. The concentration domains for the existence of free and associated molecules in the studied solutions have been assessed from the viscosity results. The gums have been found to bind a fair amount of water from the vapor phase with them. In solution, they can interact and arrest a large amount of water in their folded configuration. Intrinsic viscosities of the gums in aqueous medium declined in the presence of salts. The activation energies for their viscous flow were moderate and comparable, and were dependent on their concentrations. From the power law relation and viscosity master curve behavior mostly two critical association states of the macromolecular dispersions were envisaged.

  12. O PRAZER DA APRENDIZAGEM ATRAVÉS DA POESIA

    Directory of Open Access Journals (Sweden)

    COLI, Katiane Cristie

    2012-10-01

    Full Text Available To present researches “The pleasure of the learning through of the poetry” has for objective to emphasize the importance of pleased poetries in classroom of the fundamental teaching, proposing to the students one moment ludic, tends in view the exercise of the imagination, of the fantasy and of the creativity, developing like this a form teaching more cheerful, more poetic and with larger freedom to build the knowledge. The research also has for purpose to call the teachers’ attention for the importance of the reading of poetries in the classroom and to develop in the students the taste for her. For the accomplishment of this research works of renowned national prominence were used, among other materials. It was also accomplished a field research, in way to still give larger credibility to the study. A presente pesquisa “O prazer da aprendizagem através da poesia” teve por objetivo ressaltar a importância de poesias prazerosas em sala de aula do ensino fundamental, propondo aos alunos um momento lúdico, tendo em vista o exercício da imaginação, da fantasia e da criatividade, desenvolvendo assim um ensino de forma mais alegre, mais poético e com maior liberdade para construir o conhecimento. A pesquisa também tem por propósito chamar a atenção dos professores para a importância da leitura de poesias na sala de aula e desenvolver nos alunos o gosto por ela. Para a realização desta pesquisa foram utilizadas obras de renomado destaque nacional, entre outros materiais. Foi realizada também uma pesquisa de campo, de forma a dar maior credibilidade ao estudo.

  13. Publicidade e ética: um estudo da construção da imagem da mulher

    Directory of Open Access Journals (Sweden)

    Elizabeth Moraes Gonçalves

    2010-02-01

    Full Text Available O texto propõe uma reflexão sobre a ética da responsabilidade na publicidade veiculada nas revistas Claudia e Nova. Trata-se de uma pesquisa descritiva, resultante da leitura dos anúncios selecionados, subsidiada por teóricos da Análise do Discurso da linha francesa, que busca averiguar como a mulher é representada. Constatou-se que no contexto da sociedade contemporânea o retrato da mulher como sedutora ainda está presente, mesmo que em vários momentos ela apareça como protagonista de sua própria vida.

  14. Efeitos da acupuntura no tratamento da ansiedade: revisao integrativa

    OpenAIRE

    Sueli Leiko Takamatsu Goyatá; Carolina Costa Valcanti Avelino; Sérgio Valverde Marques dos Santos; Deusdete Inácio de Souza Junior; Maria Dorise Simão Lopes Gurgel; Fábio de Souza Terra

    2016-01-01

    RESUMO Objetivo: avaliar as evidências científicas disponíveis na literatura sobre os efeitos da acupuntura no tratamento da ansiedade e a qualidade desses estudos. Método: revisão integrativa, realizada nas bases/bancos de dados CINAHL, LILACS, PUBMEDPICO, SciELO, The Cochrane Library, no período entre 2001 a 2014. Os descritores anxiety, acupuncture therapy, acupuncture e anxiety disorders foram combinados entre si para garantir a ampla busca de estudos primários. Resultados: dos 514 art...

  15. O apagamento da oralidade na historiografia da literatura brasileira

    OpenAIRE

    Schneider, Sabrina; Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS)

    2009-01-01

    Este artigo tem, por objetivo, mostrar como a oralidade tem sido abordada – quando é abordada – pelos historiadores da literatura brasileira. Trabalha com a hipótese de que a historiografia, por meio de estratégias discursivas, tem marginalizado a oralidade, bem como a contribuição das tradições ágrafas africana e indígena. Para verificá-la, perfaz um trajeto que tem início em Ferdinand Denis, cujo "Resumo da história literária do Brasil" foi publicado em 1826, e termina em Alexei Bueno, que ...

  16. O PROJETO DA MODERNIDADE SEGUNDO HABERMAS

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    João Paulo Rodrigues

    2014-12-01

    Full Text Available O projeto acadêmico de Habermas busca contribuir para a realização das metas emancipatórias da modernidade, através da teoria da ação comunicativa. Portanto, será examinado aqui se o processo de racionalização da sociedade moderna, presente na teoria da ação comunicativa, realmente representa um potencial para a emancipação humana. Primeiramente, pretende-se abordar no respectivo trabalho os principais conceitos que Habermas utiliza em sua teoria da ação comunicativa. Em um segundo momento, serão explorados os elementos fundamentais da teoria da sociedade. Após isso, será analisada a teoria da modernidade e a sua relação com a teoria da sociedade. Tal caminho terá o objetivo de investigar a possibilidade de resgate do projeto da modernidade, ao explicar a possibilidade da teoria da ação comunicativa ser considerada o potenciador emancipatório da sociedade moderna, formando tanto o cidadão como um indivíduo autônomo, preservando a sua identidade pessoal, quanto o cidadão como participante de uma sociedade política, possuidor de uma identidade cultural, étnica, entre outras, que abrange variados grupos sociais.

  17. Extração, secagem por atomização e microencapsulamento de antocianinas do bagaço da uva "Isabel" (Vitis labrusca Extraction, spray drying and microencapsulating of 'Isabel' grape (Vitis labrusca bagasse anthocyanin

    Directory of Open Access Journals (Sweden)

    Eunice Valduga

    2008-10-01

    Full Text Available Objetivou-se obter neste trabalho um corante natural (antocianina, na forma de pó a partir do bagaço de uva da cultivar "Isabel" (Vitis labrusca, onde foram realizados estudos de extração e encapsulamento. Empregou-se o método de extração por imersão mediante técnica de planejamento experimental, onde as variáveis avaliadas foram pH da solução de extração (1-2, volume de etanol (100-250 mL, tempo de extração (3-7 h e temperatura de extração (15-35ºC. A concentração máxima de antocianinas totais obtidas foi de 300 mg/100 g de bagaço de uva (umidade 5% nos níveis inferiores de pH (1,0 e tempo (3 horas e superiores de temperatura (35ºC e volume de etanol (250 mL. Os extratos foram secos por atomização. A melhor condição para o encapsulamento e a secagem foi quando utilizaram-se proporções iguais de maltodextrina e goma arábica.This work had the aim of obtaining a natural pigment (anthocyanin at powder form from 'Isabel' grape bagasse (Vitis labrusca, studying the extraction and encapsulating steps one applied the method of extraction by immersion by experimental design technique, when the factors investigated were pH of the extraction solution (1-2, volume of ethanol (100-250 mL, extraction time (3-7 h and extraction temperature (15-35 °C. The maximum concentration of total anthocyanin was 300 mg/100g of grape bagasse (5% moisture at the lower levels of pH (1.0 and time (3 h, and at upper levels of temperature (35ºC and amount of ethanol (250 mL. The extracts were dried by a spray process. The best condition for encapsulating and drying was obtained when equal amounts of maltodextrin and Arabic gum were used.

  18. Carencia de dados e desafios metodologicos para o desenvolvimento dos estudos da industria da musica

    National Research Council Canada - National Science Library

    Herschmann, Micael

    2013-01-01

    Balanco das dificuldades metodologicas enfrentadas pelos pesquisadores que vem trabalhando com a industria da musica no contexto atual marcado pela crise e reestruturacao deste setor da producao cultural...

  19. ESTUDO DA EFICIÊNCIA DA PASTEURIZAÇÃO DA POLPA DE TAPEREBÁ (SPONDIAS MOMBIN

    Directory of Open Access Journals (Sweden)

    C. T. R. M. BASTOS

    2008-12-01

    Full Text Available

    O taperebá (Spondias mombim é uma pequena drupa elipsóide, de cor amarelo alaranjado, com casca fi na que pode ser facilmente rompida, tornando o fruto susceptível à contaminação por ação de agentes externos. Estudou-se a pasteurização da polpa de taperebá, visando estabelecer condições simples e efi cientes de conservação a temperatura ambiente. Parâmetros microbiológicos (enumeração de microrganismos mesófílos aeróbios e pesquisa de coliformes a 45°C, químicos (teor de vitamina C, enzimáticos (atividade da peroxidase – POD e colorimétricos (colorimetria tristimulus foram utilizados como variáveis de resposta. Em bancada, foram testados diferentes tempos (1 a 300 s e temperaturas (70ºC a 90ºC de tratamento térmico, não tendo sido observado efeito estatisticamente signifi cativo (p < 0,05 sobre as contagens de microrganismos mesófi los aeróbios, coliformes a 45°C e sobre a cor da polpa. Em escala piloto, realizou-se a pasteurização da polpa a 85°C por 3 minutos, sendo avaliados parâmetros de qualidade do produto durante 14 dias de manutenção a 40°C, sob iluminação artifi cial, e realizados testes sensoriais. A redução da contagem de microrganismos mesófi los aeróbios e coliformes a 45°C, para níveis aceitáveis pela legislação brasileira, a manutenção da cor e os índices de aceitação da polpa confi rmaram a efi ciência do tratamento térmico. Não se observou atividade da POD na polpa pasteurizada, devendo o controle de qualidade do produto ser feito com base nos parâmetros microbiológicos e de cor da polpa.

  20. O panorama das Drogas no México: da margem da sociedade ao centro da cultura

    Directory of Open Access Journals (Sweden)

    Diana Palaversich

    2013-12-01

    Full Text Available O artigo destaca o percurso das manifestações culturais ligadas ao tráfico de drogas no México, de um lugar marginal, de subcultura, na sociedade mexicana das décadas de 1970 e 1980, expressas principalmente através dos narcocorridos e do narcocine, para um lugar no mainstream cultural mexicano, desde o início do século 21, com destaque especial para a narcoliteratura. O aumento da violência, provocado pela guerra ao narcotráfico, produz uma proliferação da temática nos meios de comunicação e se reflete em áreas da cultura como as artes plásticas e a literatura, produzindo um novo tipo de expressão artística ou narrativa, que tanto pode ser oportunista e contribuir para a banalização da violência do narcotráfico como ser crítica e narrar o impacto individual e coletivo do tráfico de drogas, narrar a desenfreada e violenta realidade mexicana sem cair no estilo da imprensa marrom, do folclore ou dos lugares comuns dos romances de ação.

  1. CILADAS DA DIFERENÇA

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    Antônio Flávio Pierucci

    1990-12-01

    Full Text Available Este artigo procura analisar os efeitos perversos da apropriação pela esquerda de um tema definidor das tradições de direita, a saber, a diferença. Com base no caso Sears (EUA e no caso Le Pen (França, o autor aponta para as armadilhas racistas e sexistas presentes nos discursos que focalizam e enfatizam a diferença, sobretudo num período histórico de reemergência dos conservadorismos que, por sua vez, se apropriam do argumento da diferença, dirigindo-o contra os próprios movimentos de esquerda.

  2. O mito fascista da romanidade

    OpenAIRE

    Giardina, Andrea

    2008-01-01

    Este ensaio procura analisar como o mito de Roma foi utilizado por Mussolini para criar uma "especificidade" fascista que coincidisse com uma "especificidade" da nação italiana. Práticas rituais, gestos, valores, símbolos foram retomados, de forma variamente arbitrária, para construir um mito que gerava novas ambigüidades, e que constituiu, à diferença do nazismo, um empecilho para a própria sobrevivência da "romanidade" após Mussolini.

  3. Cinco discursos da digitalidade audiovisual

    Directory of Open Access Journals (Sweden)

    Gerbase, Carlos

    2001-01-01

    Full Text Available Michel Foucault ensina que toda fala sistemática - inclusive aquela que se afirma “neutra” ou “uma desinteressada visão objetiva do que acontece” - é, na verdade, mecanismo de articulação do saber e, na seqüência, de formação de poder. O aparecimento de novas tecnologias, especialmente as digitais, no campo da produção audiovisual, provoca uma avalanche de declarações de cineastas, ensaios de acadêmicos e previsões de demiurgos da mídia

  4. Cinco discursos da digitalidade audiovisual

    Directory of Open Access Journals (Sweden)

    Gerbase, Carlos

    2001-01-01

    Full Text Available Michel Foucault ensina que toda fala sistemática - inclusive aquela que se afirma “neutra” ou “uma desinteressada visão objetiva do que acontece” - é, na verdade, mecanismo de articulação do saber e, na seqüência, de formação de poder. O aparecimento de novas tecnologias, especialmente as digitais, no campo da produção audiovisual, provoca uma avalanche de declarações de cineastas, ensaios de acadêmicos e previsões de demiurgos da mídia.

  5. Escola Vila : pedagogia da sustentabilidade

    OpenAIRE

    Rocha, Ilka Maria Zoza

    2007-01-01

    Esta pesquisa teve como objetivo conhecer de que forma a educação ambiental é colocada em prática na Escola VILA de Fortaleza, buscando compreender o seu significado como conteúdo transversal e as relações que as crianças e as demais pessoas da comunidade escolar estabelecem com o ambiente, por meio da observação de como atuam e se comportam no cotidiano. Inicia situando o leitor no contexto educacional: leis e exigências, seguido dos conceitos: relação homem x meio ambiente...

  6. da Vinci decoded: does da Vinci stereopsis rely on disparity?

    Science.gov (United States)

    Tsirlin, Inna; Wilcox, Laurie M; Allison, Robert S

    2012-11-01

    In conventional stereopsis, the depth between two objects is computed based on the retinal disparity in the position of matching points in the two eyes. When an object is occluded by another object in the scene, so that it is visible only in one eye, its retinal disparity cannot be computed. Nakayama and Shimojo (1990) found that a precept of quantitative depth between the two objects could still be established for such stimuli and proposed that this precept is based on the constraints imposed by occlusion geometry. They named this and other occlusion-based depth phenomena "da Vinci stereopsis." Subsequent research found quantitative depth based on occlusion geometry in several other classes of stimuli grouped under the term da Vinci stereopsis. However, Nakayama and Shimojo's findings were later brought into question by Gillam, Cook, and Blackburn (2003), who suggested that quantitative depth in their stimuli was perceived based on conventional disparity. In order to understand whether da Vinci stereopsis relies on one type of mechanism or whether its function is stimulus dependent we examine the nature and source of depth in the class of stimuli used by Nakayama and Shimojo (1990). We use three different psychophysical and computational methods to show that the most likely source for depth in these stimuli is occlusion geometry. Based on these experiments and previous data we discuss the potential mechanisms responsible for processing depth from monocular features in da Vinci stereopsis.

  7. Efeitos da acupuntura no tratamento da ansiedade: revisao integrativa

    Directory of Open Access Journals (Sweden)

    Sueli Leiko Takamatsu Goyatá

    2016-06-01

    Full Text Available RESUMO Objetivo: avaliar as evidências científicas disponíveis na literatura sobre os efeitos da acupuntura no tratamento da ansiedade e a qualidade desses estudos. Método: revisão integrativa, realizada nas bases/bancos de dados CINAHL, LILACS, PUBMEDPICO, SciELO, The Cochrane Library, no período entre 2001 a 2014. Os descritores anxiety, acupuncture therapy, acupuncture e anxiety disorders foram combinados entre si para garantir a ampla busca de estudos primários. Resultados: dos 514 artigos, 67 foram selecionados para leitura na íntegra e 19 incluídos. Desses, 11 apresentaram forte nível de evidência. Dos seis artigos de estudos clínicos randomizados, cinco apresentaram qualidade classificada como razoável. Dois estudos utilizaram acupunturistas enfermeiros para a aplicação da intervenção. Os resultados mostram efeitos positivos e estatisticamente significativos do uso da acupuntura para tratamento de indivíduos com ansiedade. Conclusão: a acupuntura parece ser um tratamento promissor para a ansiedade, no entanto, há necessidade de melhorar a qualidade metodológica das pesquisas nessa temática.

  8. Efeito da urina de vaca no estado nutricional da alface

    Directory of Open Access Journals (Sweden)

    Nelson Licínio C. de Oliveira

    2010-08-01

    Full Text Available Existem diversos relatos da utilização da urina de vaca em hortaliças, todavia sua eficácia carece de comprovação. Objetivou-se avaliar o efeito da urina de vaca no estado nutricional da alface. O experimento foi constituído de 12 tratamentos, esquema de parcelas subdivididas, em blocos ao acaso, com quatro repetições. Nas parcelas foram alocadas as vias de aplicação (solo ou foliar e nas subparcelas as concentrações das soluções (0,00; 0,25; 0,50; 0,75; 1,00 e 1,25% v/v. Aplicou-se 60 mL de solução/planta, divididos em cinco aplicações de 5; 5; 10; 20 e 20 mL/planta, aos 7, 14, 21, 28 e 35 após o transplante, respectivamente. Durante o ciclo avaliou-se o índice SPAD e na colheita a massa da matéria seca de cabeça (MSCA e os teores de N, P, K, Ca, Mg, S, Na, Zn, Fe, Mn, Cu e B na matéria seca das folhas (MSF, caule (MSC e raízes (MSR. Em ambas as vias de aplicação o índice SPAD apresentou incremento linear às concentrações e resposta quadrática ao longo do tempo. A MSCA teve comportamento linear às concentrações, com aumento de 25,9 e 35,4% nas aplicações via foliar e solo, respectivamente. Não houve efeito de concentrações sobre teores de nutrientes na MSF e MSC. Na MSR, via solo, os teores de P e K apresentaram pontos de máximo enquanto Fe e Mn de mínimo; o Na apresentou incremento linear às concentrações via foliar. Os efeitos da urina sobre o crescimento da alface provavelmente são devidos a fatores outros que não somente a quantidade de nutrientes veiculados nas soluções.

  9. Efeito agudo da suplementacao da cafeina no desempenho da forca muscular e alteracoes cardiovasculares durante o treino de forca

    National Research Council Canada - National Science Library

    Materko, W; Santos, E.L

    2011-01-01

    A proposta do presente estudo foi avaliar o efeito agudo da cafeina no desempenho da forca muscular, paralelamente a possiveis alteracoes hemodinamicas ao longo de uma sessao de treino de forca muscular...

  10. Laser de diodo no tratamento da retinopatia da prematuridade

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    Liarth Josilene de Carvalho Soares

    2001-01-01

    Full Text Available Objetivo: Determinar a eficácia do laser de diodo e suas complicações no tratamento da retinopatia da prematuridade, estágio 3 limiar. Métodos: De 348 crianças pré-termo examinadas na Clínica Oftalmológica do Hospital Getúlio Vargas e Instituto de Olhos do Piauí, em Teresina, Piauí, no período de julho/89 a março/99, 152 (43,7% apresentaram retinopatia da prematuridade. As crianças com retinopatia da prematuridade no estágio 3 limiar foram submetidas a laserablação retiniana com laser de diodo indireto, no centro cirúrgico, sob anestesia geral. Resultados: Vinte crianças (38 olhos foram submetidas a laserablação retiniana. Doze pacientes (80,0% tiveram regressão da retinopatia e três (20,0% evoluíram para o estágio 5. Cinco crianças não retornaram para controle, sendo excluídas do estudo quanto aos resultados do laser. Não foram observadas complicações oculares. Cinco crianças apresentaram apnéia relacionada à anestesia. Conclusões: Neste grupo de crianças, o laser de diodo foi eficaz em 80,0% dos pacientes tratados. As complicações encontradas (cinco casos de apnéia se relacionaram possivelmente à anestesia geral.

  11. A identidade à flor da pele: etnografia da prática da tatuagem na contemporaneidade

    Directory of Open Access Journals (Sweden)

    Andrea Lissett Pérez

    2006-04-01

    Full Text Available No presente artigo, realiza-se uma descrição etnográfica da prática da tatuagem na contemporaneidade, a partir de uma perspectiva que prioriza as noções da prática, das interações e das experiências vividas durante o processo de ser tatuado. A reflexão tenta reconstruir uma visão total da prática da tatuagem que abrange o mundo subjetivo e as dinâmicas sociais como partes constitutivas desse ato. Entre as idéias conclusivas estão, de um lado, o surgimento de uma nova normalidade estética e vivencial no seio da sociedade ocidental e, de outro, a configuração de uma nova subjetividade, a dos "tatuados", como um processo interativo, inovador, emotivo e reflexivo, em que o corpo se converte em uma forma de expressão e construção do sujeito.This article provides a descriptive account of contemporary tattooing, based on a perspective that prioritizes the notion of practice, as well as the interactions and experiences involved in the process of being tattooed. The analysis attempts to rebuild a holistic view of tattooing, combining subjective processes and social dynamics as equally constitutive parts of this activity. Among the conclusions reached are: (a the emergence of tattooing as a new aesthetic norm and a lived experience at the heart of the western society; and (b the configuration of a new subjectivity, the ‘tattooed,’ as an interactive, innovative, emotional and reflexive process in which the body is converted into a form of expressing and constructing the subject.

  12. O panorama das Drogas no México: da margem da sociedade ao centro da cultura

    OpenAIRE

    Diana Palaversich

    2013-01-01

    O artigo destaca o percurso das manifestações culturais ligadas ao tráfico de drogas no México, de um lugar marginal, de subcultura, na sociedade mexicana das décadas de 1970 e 1980, expressas principalmente através dos narcocorridos e do narcocine, para um lugar no mainstream cultural mexicano, desde o início do século 21, com destaque especial para a narcoliteratura. O aumento da violência, provocado pela guerra ao narcotráfico, produz uma proliferação da temática nos meios de comunicação e...

  13. O panorama das Drogas no México: da margem da sociedade ao centro da cultura

    OpenAIRE

    Diana Palaversich

    2013-01-01

    O artigo destaca o percurso das manifestações culturais ligadas ao tráfico de drogas no México, de um lugar marginal, de subcultura, na sociedade mexicana das décadas de 1970 e 1980, expressas principalmente através dos narcocorridos e do narcocine, para um lugar no mainstream cultural mexicano, desde o início do século 21, com destaque especial para a narcoliteratura. O aumento da violência, provocado pela guerra ao narcotráfico, produz uma proliferação da temática nos meios de comunicação e...

  14. Novas e velhas abordagens da teoria da escolha e da utilidade

    OpenAIRE

    Wagner, Sergio Artur Luz

    2009-01-01

    Até pouco tempo havia apenas um posicionamento frente o dilema da escolha envolvendo o risco, que era baseado no processo do indivíduo racional. Atualmente, com novas técnicas de compreensão do risco e principalmente do complexo instituto da incerteza, já é possível de se delimitar o que leva as pessoas a decidirem e a se equivocarem em alguns processos de decisão. Neste trabalho apresentaremos um pequeno resumo histórico dos processos, visando certa linha de pensamento, no que tange aos meca...

  15. Mulheres da Norô

    Directory of Open Access Journals (Sweden)

    Flavia Liberman

    Full Text Available O projeto Cartografias femininas: ações territoriais junto às mulheres da região noroeste de Santos realiza diferentes ações em uma região que apresenta vulnerabilidade social e ambiental na cidade de Santos. Envolvendo docentes e estudantes de diferentes cursos de graduação da área da saúde da Universidade Federal de São Paulo, campus Baixada Santista, teve como resultado uma Exposição Fotográfica itinerante cujas imagens explicitam um processo de construção de vínculos com as participantes. A fotógrafa Nice Gonçalvez, do Instituto Arte no Dique, acompanhou e fotografou momentos desta experiência, oferecendo-nos um material delicado que retrata seus rostos, corpos, detalhes e expressividades. Esta exposição ofereceu, às mulheres, uma oportunidade de reconhecerem-se como protagonistas ativas e fortes em todo o processo, tornando-as visíveis para além das fronteiras de suas casas, de seu bairro ou, mesmo, de sua região.

  16. Tratamento da dor em queimados

    Directory of Open Access Journals (Sweden)

    Rodrigo José Alencar de Castro

    2013-02-01

    Full Text Available JUSTIFICATIVA E OBJETIVOS: Apesar dos avanços, ainda é observado manejo analgésico inadequado dos pacientes com queimaduras. O objetivo desta revisão foi coletar dados sobre tratamento da dor em queimados. CONTEÚDO: Foi feita revisão sobre os mecanismos de dor, avaliação do paciente com queimadura e o tratamento farmacológico e não farmacológico. CONCLUSÕES: O manejo da dor em pacientes vítimas de queimaduras ainda é um desafio por parte da equipe multiprofissional. A avaliação frequente e contínua da resposta apresentada pelo paciente é muito importante, tendo em vista os vários momentos por que passa o paciente internado em decorrência de uma queimadura, além de uma terapêutica combinada com medicações analgésicas e medidas não farmacológicas. Entender a complexidade de alterações fisiopatológicas, psicológicas e bioquímicas apresentadas por um paciente em tratamento de queimadura é o primeiro passo para alcançar o sucesso no seu manejo analgésico.

  17. Leonardo da Vinci and the Downburst.

    Science.gov (United States)

    Gedzelman, Stanley David

    1990-05-01

    Evidence from the drawings, experiments, and writings of Leonardo da Vinci are presented to demonstrate that da Vinci recognized and, possibly, discovered the downburst and understood its associated airflow. Other early references to vortex flows resembling downbursts are mentioned.

  18. A LINGUAGEM TÉCNICA DA ECONOMIA

    Directory of Open Access Journals (Sweden)

    Tânia Pitombo de Oliveira

    2011-07-01

    Full Text Available Monografia de linguística que trata da linguagem de jornal dentro da área econômica. Focaliza essencialmente o léxico da linguagem técnica desta área de interesse, de um artigo de jornal. Elaborada para a disciplina de Linguística V, Departamento de Letras, Centro de Ciências Humanas, Letras e Artes da Universidade Estadual de Maringá, em 1985.

  19. BASES DE UMA TEORIA DO DELITO A PARTIR DA FILOSOFIA DA LINGUAGEM

    OpenAIRE

    Busato, Paulo César; Universidade Federal do Paraná, Curitiba/PR

    2012-01-01

    O presente artigo trata das bases que conduzem à estruturação de uma teoria do delito a partir da filosofia da linguagem. Apresenta-se a estrutura formada pela ação significativa, a liberdade de ação e a teoria