Efeito anti-inflamat��rio e antioxidante do extrato hidroalc��olico de Turnera subulata na colite ulcerativa induzida por ��cido ac��tico em ratos

Inflammatory bowel diseases is composed by a set of chronic and inflammatory disorders, among them is ulcerative colitis (UC). UC treatment is based on anti-inflammatory administration; however, this group of drugs clearly leads to development of undesirable side effects, what stimulate the search for new therapies alternatives. The aim of this study was to evaluate the effect of hydroalcholic Turnera subulata extract on acetic acid-induced acute UC in rats. UC was induced by 1 mL injection of 4% acetic acid via rectal in Wistar mouse. 42 animals were distributed among 6 experimental groups: Control, UC, Sulfasalazine 500 mg/Kg/day (SSZ), T. subulata 50mg/Kg/day (TS 50), T. subulata 100mg/Kg/day (TS 100), T. subulata 200mg/Kg/day (TS 200). Throughout the experiment, body weight, food and water ingestion was daily evaluated. At the end of the experiment, the animals were euthanized and a colon fragment was observed by macroscopic analysis. Colon fragments were also collected for microscopic analysis and oxidative stress evaluation. The means from each group was compared by ANOVA test with a significance level of 5% (p<0.05) using GraphPad Prism Software. As results, we can clearly observe that SSZ group had the greater body weight decrease among the groups throughout the experiments, 14.78%, as well as, the lowest food intake, 6.23 g of food/day. The animals treated with T. subulata extracts showed no important body weight loss when compared to control. UC group showed the highest tissue damage macroscope score, 6.5, while TS 50 showed the lowest tissue damage score: 1. Microscope evaluation showed the presence of edema, haemorraghia and ulceration in all group of animals, except for Control. Nevertheless, TS 50 showed the lowest inflammatory damage among all groups. Oxidative stress analysis revealed that T. subulata treatment modulate catalase and superoxide dismutase activity, we also observed a decrease in protein and lipid peroxidation in response to extract administration. Taken together, these results shows that T. subulata extract exerts anti-inflammatory and anti-oxidant effects on experimental UC.

Efeito anti-inflamat��rio e antioxidante do extrato hidroalc��olico de Turnera subulata na colite ulcerativa induzida por ��cido ac��tico em ratos

Inflammatory bowel diseases is composed by a set of chronic and inflammatory disorders, among them is ulcerative colitis (UC). UC treatment is based on anti-inflammatory administration; however, this group of drugs clearly leads to development of undesirable side effects, what stimulate the search for new therapies alternatives. The aim of this study was to evaluate the effect of hydroalcholic Turnera subulata extract on acetic acid-induced acute UC in rats. UC was induced by 1 mL injection of 4% acetic acid via rectal in Wistar mouse. 42 animals were distributed among 6 experimental groups: Control, UC, Sulfasalazine 500 mg/Kg/day (SSZ), T. subulata 50mg/Kg/day (TS 50), T. subulata 100mg/Kg/day (TS 100), T. subulata 200mg/Kg/day (TS 200). Throughout the experiment, body weight, food and water ingestion was daily evaluated. At the end of the experiment, the animals were euthanized and a colon fragment was observed by macroscopic analysis. Colon fragments were also collected for microscopic analysis and oxidative stress evaluation. The means from each group was compared by ANOVA test with a significance level of 5% (p<0.05) using GraphPad Prism Software. As results, we can clearly observe that SSZ group had the greater body weight decrease among the groups throughout the experiments, 14.78%, as well as, the lowest food intake, 6.23 g of food/day. The animals treated with T. subulata extracts showed no important body weight loss when compared to control. UC group showed the highest tissue damage macroscope score, 6.5, while TS 50 showed the lowest tissue damage score: 1. Microscope evaluation showed the presence of edema, haemorraghia and ulceration in all group of animals, except for Control. Nevertheless, TS 50 showed the lowest inflammatory damage among all groups. Oxidative stress analysis revealed that T. subulata treatment modulate catalase and superoxide dismutase activity, we also observed a decrease in protein and lipid peroxidation in response to extract administration. Taken together, these results shows that T. subulata extract exerts anti-inflammatory and anti-oxidant effects on experimental UC.

Avalia����o da influ��ncia de surfactantes qu��mico e biol��gico na hidr��lise enzim��tica de casca de coco verde ap��s pr��-tratamento ��cido/alcalino e com per��xido de hidrog��nio alcalino

In Brazil many types of bioproducts and agroindustrial waste are generated currently, such as cacashew apple bagasse and coconut husk, for example. The final disposal of these wastes causes serious environmental issues. In this sense, waste lignocellulosic content, as the shell of the coconut is a renewable and abundant raw material in which its use has an increased interest mainly for the 2nd generation ethanol production. The hydrolysis of cellulose to reducing sugars such as glucose and xylose is catalysed by a group of enzymes called cellulases. However, the main bottleneck in the enzymatic hydrolysis of cellulose is the significant deactivation of the enzyme that shows irreversible adsorption mechanism leading to reduction of the cellulose adsorption onto cellulose. Studies have shown that the use of surfactants can modify the surface property of the cellulose therefore minimizing the irreversible binding. The main objective of the present study was to evaluate the influence of chemical and biological surfactants during the hydrolysis of coconut husk which was subjected to two pre-treatment in order to improve the accessibility of the enzymes to the cellulose, removing this way, part of the lignin and hemicellulose present in the structure of the material. The pre-treatments applied to coconut bagasse were: Acid/Alkaline using 0.6M H2SO4 followed by 1M NaOH, and the one with Alkaline Hydrogen Peroxide at a concentration of 7.35% (v/v) and pH 11.5. Both the material no treatment and pretreated were characterized using analysis of diffraction X-ray (XRD), Scanning Electron Microscopy (SEM) and methods established by NREL. The influence of both surfactants, chemical and biological, was used at concentrations below the critical micelle concentration (CMC), and the concentrations equal to the CMC. The application of pre-treatment with coconut residue was efficient for the conversion to glucose, as well as for the production of total reducing sugars, it was possible to observe that the pretreatment fragmented the structure as well as disordered the fibers. Regarding XRD analysis, a significant increase in crystallinity index was observed for pretreated bagasse acid/alkali (51.1%) compared to the no treatment (31.7%), while that for that treated with PHA, the crystallinity index was slightly lower, around 29%. In terms of total reducing sugars it was not possible to observe a significant difference between the hydrolysis carried out without the use of surfactant compared to the addition of Triton and rhamnolipid. However, by observing the conversions achieved during the hydrolysis, it was noted that the best conversion was using the rhamnolip��d for the husk pretreated with acid/alkali, reaching a value of 33%, whereas using Triton the higher conversion was 23.8%. The coconut husk is a residue which can present a high potential to the 2nd generation ethanol production, being the rhamonolipid a very efficient biosurfactant for use as an adjuvant in the enzymatic process in order to act on the material structure reducing its recalcitrance and therefore improving the conditions of access for enzymes to the substrate increasing thus the conversion of cellulose to glucose.

Avalia����o da influ��ncia de surfactantes qu��mico e biol��gico na hidr��lise enzim��tica de casca de coco verde ap��s pr��-tratamento ��cido/alcalino e com per��xido de hidrog��nio alcalino

In Brazil many types of bioproducts and agroindustrial waste are generated currently, such as cacashew apple bagasse and coconut husk, for example. The final disposal of these wastes causes serious environmental issues. In this sense, waste lignocellulosic content, as the shell of the coconut is a renewable and abundant raw material in which its use has an increased interest mainly for the 2nd generation ethanol production. The hydrolysis of cellulose to reducing sugars such as glucose and xylose is catalysed by a group of enzymes called cellulases. However, the main bottleneck in the enzymatic hydrolysis of cellulose is the significant deactivation of the enzyme that shows irreversible adsorption mechanism leading to reduction of the cellulose adsorption onto cellulose. Studies have shown that the use of surfactants can modify the surface property of the cellulose therefore minimizing the irreversible binding. The main objective of the present study was to evaluate the influence of chemical and biological surfactants during the hydrolysis of coconut husk which was subjected to two pre-treatment in order to improve the accessibility of the enzymes to the cellulose, removing this way, part of the lignin and hemicellulose present in the structure of the material. The pre-treatments applied to coconut bagasse were: Acid/Alkaline using 0.6M H2SO4 followed by 1M NaOH, and the one with Alkaline Hydrogen Peroxide at a concentration of 7.35% (v/v) and pH 11.5. Both the material no treatment and pretreated were characterized using analysis of diffraction X-ray (XRD), Scanning Electron Microscopy (SEM) and methods established by NREL. The influence of both surfactants, chemical and biological, was used at concentrations below the critical micelle concentration (CMC), and the concentrations equal to the CMC. The application of pre-treatment with coconut residue was efficient for the conversion to glucose, as well as for the production of total reducing sugars, it was possible to observe that the pretreatment fragmented the structure as well as disordered the fibers. Regarding XRD analysis, a significant increase in crystallinity index was observed for pretreated bagasse acid/alkali (51.1%) compared to the no treatment (31.7%), while that for that treated with PHA, the crystallinity index was slightly lower, around 29%. In terms of total reducing sugars it was not possible to observe a significant difference between the hydrolysis carried out without the use of surfactant compared to the addition of Triton and rhamnolipid. However, by observing the conversions achieved during the hydrolysis, it was noted that the best conversion was using the rhamnolip��d for the husk pretreated with acid/alkali, reaching a value of 33%, whereas using Triton the higher conversion was 23.8%. The coconut husk is a residue which can present a high potential to the 2nd generation ethanol production, being the rhamonolipid a very efficient biosurfactant for use as an adjuvant in the enzymatic process in order to act on the material structure reducing its recalcitrance and therefore improving the conditions of access for enzymes to the substrate increasing thus the conversion of cellulose to glucose.

Avalia����o do banco de disserta����es e teses da associa����o brasileira de antropologia: uma an��lise cienciom��trica

VITULLO, Nadia Aurora Vanti. Avalia����o do banco de disserta����es e teses da Associa����o Brasileira de Antropologia: uma an��lise cienciom��trica. 2001. 143 f. Disserta��ao (Mestrado) - Curso de Mestrado em Biblioteconomia e Ci��ncia da Informa����o, Pontif��cia Universidade Cat��lica de Campinas, Campinas, 2001.

Biblioteca digital de teses e disserta��oes: uma refer��ncia fundamental

OLIVEIRA, Raimundo Muniz de. Biblioteca digital de teses e disserta��oes: uma referencia fundamental. In: CINFORM ENCONTRO NACIONAL DE ENSINO E PESQUISA DA INFORMA��AO,HUMANISMO E DESENVOLVIMENTO CIENTIFICO E TECNOLOGICO,7.,2007,Salvador. Anais...Salvador:UFBA, 2007.Disponivel em:www.cinform.ufba.br>. Acesso em: 27 set. 2007. Acesso em: 27 set. 2010.

Bibblioteca Digital de Teses e Disserta����es: uma estrat��gia de preserva����o digital

CUNHA, Jacqueline de Ara��jo. Biblioteca Digital de Teses e Disserta����es: uma estrat��gia de preserva����o da mem��ria cient��fica. 2009. 141f. Disserta����o (Mestrado)- Programa de P��s-Gradua����o em Ci��ncia da Informa����o. Universidade Federal da Para��ba, Jo��o Pessoa, 2009.

Biblioteca Digital de Teses e Disserta����es: grau de utiliza����o pelos mestrandos do curso de Ci��ncia da Informa����o das Universidades P��blicas Brasileiras

A pesquisa aborda o uso das Tecnologias de Informa����o e Comunica����o, que vem revolucionando as atividades e ocasionando muitas mudan��as relacionadas ao acesso e uso de informa����es. O objetivo foi analisar o grau de utiliza����o do conhecimento cient��fico produzido pelos Programas de P��s-Gradua����o das Universidades P��blicas Brasileiras, atrav��s da BDTD, pelos mestrandos dos referidos programas. Nos procedimentos metodol��gicos realizados, procurou-se inicialmente analisar o amplo espectro da popula����o do corpus da pesquisa. Em raz��o da impossibilidade de trabalhar com os Programas de P��s-Gradua����o como um todo, optou-se por fazer um recorte, elegendo os cursos de P��s-Gradua����o em Ci��ncia da Informa����o, vez que estes representam o principal segmento social de interesse da pesquisa. Foi utilizado o m��todo de estudo de usu��rios, onde se optou por adotar o grupo, ���estudos orientados aos usu��rios���, que identifica as necessidades e comportamento de acesso e uso da informa����o. Para coletar os dados, elaborou-se um question��rio semi-estruturado com 25 quest��es, que versavam sobre o uso, dificuldades de acesso e recupera����o da informa����o, bem como a satisfa����o na utiliza����o dessa fonte informacional. Dentre os v��rios resultados obtidos, podemos destacar o fato de que a maioria dos mestrandos (71,8%) s�� teve contato com a BDTD somente no momento em que se encontrava cursando o mestrado e, somente 24,3%, tiveram contato durante a gradua����o. Estes resultados representam um problema, que pode afetar o bom desempenho do projeto BDTD, o qual consiste em disseminar e divulgar a produ����o cient��fica dos Programas de P��s-Gradua����o das Universidades P��blicas Brasileiras para a sua comunidade. Foi observado tamb��m, que os mestrandos oriundos do curso de Biblioteconomia tende a ter contato com a BDTD bem mais cedo do que mestrandos de outros cursos de gradua����o. A fim de minimizar o problema detectado, prop��e-se uma divulga����o mais eficaz na gradua����o atrav��s de dois procedimentos: Primeiro, o docente deve fazer uma divulga����o mais eficaz da BDTD junto aos discentes de todos os cursos de gradua����o; segundo: dever�� ser feita a divulga����o na m��dia eletr��nica, atrav��s da inser����o de ��cones da BDTD, nos portais dos Departamentos dos Cursos de Gradua����o das Universidades P��blicas Brasileiras. Acredita-se que com estes procedimentos seja poss��vel aperfei��oar o uso dessa fonte de informa����o cient��fica.

Bibliotecas digitais de teses e disserta����es brasileiras: paradigma do acesso livre �� informa����o cient��fica

A evolu����o da comunica����o cient��fica ao longo do tempo e o impacto causado pela A evolu����o da comunica����o cient��fica ao longo do tempo e o impacto causado pela A evolu����o da comunica����o cient��fica ao longo do tempo e o impacto causado pela se analisar as contribui����es da Biblioteca Digital de Teses e Disserta����es (BDTD)para a comunica����o cient��fica atual, destacando possibilidades emergentes e desafios a serem superados. Apresenta uma breve evolu����o da comunica����o cient��fica ao longo do tempo; discute os impactos causados pela Internet na comunica����o, disponibiliza����o e acessibilidade de informa����es t��cnico-cient��ficas; e caracteriza BDTD destacando os desafios a serem superados. Dentre eles est��o, a quest��o dos direitos autorais que ocasionam a baixa ades��o dos autores ao projeto piloto do IBICT para disponibilizar teses e disserta����es no meio eletr��nico. Para este desafio, s��o apontadas sugest��es.

Panorama brasileiro das bibliotecas digitais de teses e disserta����es

As bibliotecas de teses e disserta����es t��m um papel fundamental para o desenvolvimento cient��fico e cultural de um pa��s. Nesse sentido, buscou-se, de modo geral, analisar o panorama brasileiro das bibliotecas digitais de teses e disserta����es. Especificamente, objetivou-se caracterizar a sociedade da informa����o enquanto contexto das BDTD; caracterizar os v��rios tipos de bibliotecas surgidos a partir da inser����o das novas tecnologias de informa����o e comunica����o; identificar as diretrizes norteadoras da implanta����o de BDTD; e levantar as BDTD existentes no Brasil. Para tato, al��m de levantamento bibliogr��fico, realizou-se uma pesquisa nos sites de institui����es de ensino superior brasileiras que j�� disp��e de bibliotecas digitais de teses e disserta����es em funcionamento. A an��lise e interpreta����o destes dados nos permite considerar que no Brasil as BDTD encontram-se num est��gio embrion��rio, sendo relevante pesquisar a hist��rica implanta����o e configura����o desse novo modelo de biblioteca.

Estudos de Durabilidade Frente ao Ataque Ácido de Comp��sitos Portland-Pol��mero para Cimenta����o de Po��os de Petr��leo

Portland-polymers composites are promising candidates to be used as cementing material in Northeastern oil wells of Brazil containing heavy oils submitted to steam injection. In this way, it is necessary to evaluate its degradation in the commonly acidizind agents. In addition, to identify how aggressive are the different hostile environments it is an important contribution on the decision of the acidic systems to be used in. It was investigated the performance of the Portland-polymer composites using powdered polyurethane, aqueous polyurethane, rubber tire residues and a biopolymer, those were reinforced with polished carbon steel SAE 1045 to make the electrochemical measurements. HCl 15,0 %, HCl 6,0 % + HF 1,5 % (soft mud acid), HCl 12,0 % + HF 3,0 % (regular mud acid) and HAc 10 % + HF 1,5 % were used as degrading environment and electrolytes. The more aggressive acid solution to the plain Portland hardened cement paste was the regular mud acid, that showed loss of weight around 23.0 %, followed by the soft mud acid, the showed 11.0 %, 15.0 % HCl with 7,0 % and, at last the 10.0 % HAc plus HF 1.5 % with just 1.0 %. The powdered polyurethane-composite and the aqueous polyurethane one showed larger durability, with reduction around 87.0 % on the loss of weight in regular mud acid. The acid attack is superficial and it occurs as an action layer, where the degraded layer is responsible for the decrease on the kinetic of the degrading process. This behavior can be seen mainly on the Portland- aqueous polyurethane composite, because the degraded layer is impregnated with chemically modified polymer. The fact of the acid attack does not have influence on the compressive strength or fratography of the samples, in a general way, confirms that theory. The mechanism of the efficiency of the Portland-polymers composites subjected to acid attack is due to decreased porosity and permeability related with the plain Portland paste, minor quantity of Ca+2, element preferentially leached to the acidic solution, wave effect and to substitute part of the degrading bulk for the polymeric one. The electrolyte HAc 10 % + HF 1,5 % was the least aggressive one to the external corrosion of the casing, showing open circuit potentials around +250 mV compared to -130 mV to the simulated pore solution to the first 24 hours immersion. This behavior has been performed for two months at least. Similar corrosion rates were showed between both of the electrolytes, around 0.01 &#956;A.cm-2. Total impedance values, insipient arcs and big polarization resistance capacitive arcs on the Nyquist plots, indicating passivity process, confirm its efficiency. In this way, Portlandpolymers composites are possible solutions to be succeed applied to oilwell cementing concomitant submitted to steam injection and acidizing operation and the HAc 10,0 % + HF 1,5 % is the less aggressive solution to the external corrosion of the casing

S��ntese e caracteriza����o do poli(��cido l��ctico) para potencial uso em sistemas de libera����o controlada de f��rmacos

With the advances in medicine, life expectancy of the world population has grown considerably in recent decades. Studies have been performed in order to maintain the quality of life through the development of new drugs and new surgical procedures. Biomaterials is an example of the researches to improve quality of life, and its use goes from the reconstruction of tissues and organs affected by diseases or other types of failure, to use in drug delivery system able to prolong the drug in the body and increase its bioavailability. Biopolymers are a class of biomaterials widely targeted by researchers since they have ideal properties for biomedical applications, such as high biocompatibility and biodegradability. Poly (lactic acid) (PLA) is a biopolymer used as a biomaterial and its monomer, lactic acid, is eliminated by the Krebs Cycle (citric acid cycle). It is possible to synthesize PLA through various synthesis routes, however, the direct polycondensation is cheaper due the use of few steps of polymerization. In this work we used experimental design (DOE) to produce PLAs with different molecular weight from the direct polycondensation of lactic acid, with characteristics suitable for use in drug delivery system (DDS). Through the experimental design it was noted that the time of esterification, in the direct polycondensation, is the most important stage to obtain a higher molecular weight. The Fourier Transform Infrared (FTIR) spectrograms obtained were equivalent to the PLAs available in the literature. Results of Differential Scanning Calorimetry (DSC) showed that all PLAs produced are semicrystalline with glass transition temperatures (Tgs) ranging between 36 - 48 ��C, and melting temperatures (Tm) ranging from 117 to 130 ��C. The PLAs molecular weight characterized from Size Exclusion Chromatography (SEC), varied from 1000 to 11,000 g/mol. PLAs obtained showed a fibrous morphology characterized by Scanning Electron Microscopy (SEM)

S��ntese do Poli (��cido l��ctico) por policondensa����o direta utilizando um planejamento fatorial

The environmental impact caused by the disposal of non-biodegradable polymer packaging on the environment, as well as the high price and scarcity of oil, caused increase of searches in the area of biodegradable polymers from renewable resources were developed. The poly (lactic acid) (PLA) is a promising polymer in the market, with a large availability of raw material for the production of its monomer, as well as good processability. The aimed of this study was synthesis PLA by direct polycondesation of lactic acid, using the tool of experimental design (DOE) (central composite rotatable design (CCRD)) to optimize the conditions of synthesis. The polymer obtained was characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), viscosimetric analysis, differential scanning calorimeter (DSC) and size exclusion chromatography (SEC). The results confirmed the formation of a poly (lactic acid) semicrystalline in the syntheses performed. Through the central composite rotatable design was possible to optimize the crystallization temperature (Tc) and crystallinity degree (Xc). The crystallization temperature maximum was found for percentage of catalyst around the central point (0,3 (%W)) and values of time ranging from the central point (6h) to the upper level (+1) (8h). The crystallization temperature maximum was found for the total synthesis time of 4h (-1) and percentage of catalyst 0,1(W%) (-1). The results of size exclusion chromatography (SEC) showed higher molecular weights to 0,3 (W%) percent of catalyst and total time synthesis of 3,2h