Oxidação de carboidratos via catálise metálica não enzimática para aplicação em sensores

This work has main aim of is to propose the synthesis and characterization of nanostructured materials for oxidation of carbohydrates such as glucose, with non-enzymatic catalysis. The proposed pathway of synthesis of metal catalysts is the polyol method and techniques of physical characterization proposals for analysis of prepared catalyst pass through diffraction technique of ray-x (DRX), scanning electron microscopy (SEM) and Energy Dispersive Spectroscopy ray-x (EDX). Technical proposals for the electrochemical characterization of the synthesized catalysts are Cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The prospects of this work are compared by the catalytic activity of the sensor designed with non-enzymatic sensors and biosensors also known in the literature

Análise proteômica da levedura Saccharomyces cerevisiae CAT-1 cultivada em diferentes concentrações de sacarose

Pós-graduação em Biotecnologia - IQ

Avaliação do bandeamento cromossômico por digestão enzimática e tratamento com solução tampão citratado

Pós-graduação em Pesquisa e Desenvolvimento (Biotecnologia Médica) - FMB

Efeito da ovariectomia e da reposição hormonal no reimplante dentário imediato: análise histomorfométrica e imunoistoquímica em ratas

Pós-graduação em Odontologia - FOA

Avaliação térmica e estrutural do bagaço de cana de açúcar pré-tratado com ozônio, ultrassom e micro-ondas para produção de etanol celulósico por hidrólise enzimática

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Análise do potencial de micro-organismos dos gêneros Lectthophora e Cryptococcus para a produção de biocumbustíveis

A busca de novas fontes de energia tem sido estimulada pela demanda crescente do mercado e o bioetanol é uma alternativa promissora para esta questão. A produção de etanol a partir de resíduos agroindustriais lignocelulósicos está sendo pesquisada em vários laboratórios do Brasil e do exterior. Os resíduos da agroindústria são formados, em grande parte, por fibra vegetal lignocelulósica, a qual é altamente resistente à degradação, dificultando a conversão dos componentes a monossacarídeos fermentescíveis. Desta forma, a prospecção de micro-organismos que viabilizem a conversão de material lignocelulósico em etanol tem aumentado consideravelmente. Sendo assim, o estudo de micro-organismos associados às formigas cortadeiras, os quais são adaptados ao uso da biomassa lignocelulolítica, pode ser promissor para a descoberta de enzimas adequadas à degradação eficiente da fibra vegetal, podendo significar um passo adiante na produção do etanol de segunda geração. Neste trabalho analisamos a ação hidrolítica e a liberação de açúcares fermentescíveis por fungos dimórficos do gênero Lecythophora e de leveduras do gênero Cryptococcus sobre o material lignocelulósico. A metodologia empregada consistiu na inoculação das linhagens em diferentes resíduos da agroindústria, como bagaço de cana-de-açúcar, casca de café, casca de arroz e sabugo de milho triturado, seguida da quantificação dos açúcares redutores liberados, bem como da produção de enzimas hidrolíticas extracelulares, como endoamilase, exoamilase, pectinase, endoglucanase, exoglucanase e xilanase. O gênero Lecythophora mostrou-se melhor produtor enzimático quando comparado com o gênero Cryptococcus, ambos em meio suplementado com bagaço de cana-de-açúcar. Ainda, foi realizado o inóculo de culturas mistas das melhores linhagens pertencentes ao gênero Lecythophora. A produção enzimática constatada indicou o potencial das linhagens...

Biocompatibilidade de primers e adesivo utilizados na confecção de próteses maxilofaciais implantorretidas: análise in vitro

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Fungos endofíticos em Eugenia brasiliensis: prospecção química, biológica, enzimática e avaliação do co-cultivo e epigenética em Xylaria cubensis, Diaporthe sp. e Colletotrichum sp.

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Síntese enzimática de ésteres de açúcar: surfactantes e polímeros como novos materiais ambientalmente seguros

Sugar esters are substances which possess surfactant, antifungical and bactericidal actions and can be obtained through two renewable sources of raw materials: sugars and vegetable oils. Their excellent biodegradability, allied to lhe fact that they are non toxic, insipid, inodorous, biocompatible, no-ionic, digestible and because they can resist to adverse conditions of temperature, pH and salinity, explain lhe crescent use of these substances in several sections of lhe industry. The objective of this thesis was to synthesize and characterize surfactants and polymers containing sugar branched in their structures, through enzymatic transesterification of vinyl esters and sugars, using alkaline protease from Bacillus subtilis as catalyst, in organic medium (DMF).Three types of sugars were used: L-arabinose, D-glucose and sucrose and two types of vinyl esters: vinyl laurate and vinyl adipate. Aiming to reach high conversions from substrates to products for a possible future large scale industrial production, a serie of variables was optimized, through Design of Experiments (DOE), using Response Surface Methodology (RSM).The investigated variables were: (1) enzyme concentration; (2) molar reason of substrates; (3) water/solvent rale; (4) temperature and (5) time. We obtained six distinct sugar esters: 5-0-lauroyl L-arabinose, 6-0-lauroyl D-glucose, 1'-O-lauroyl sucrose, 5-0-vinyladipoyl L-arabinose, 6-0-vinyladipoyl D-glucose and 1 '-O-vinyladipoyl sucrose, being lhe last three polymerizable. The progress of lhe reaction was monitored by HPLC analysis, through lhe decrease of sugar concentration in comparison to lhe blank. Qualitative analysis by TLC confirmed lhe formation of lhe products. In lhe purification step, two methodologies were adopted: (1) chromatographic column and (2) extraction with hot acetone. The acylation position and lhe chemical structure were determined by 13C-RMN. The polymerization of lhe three vinyl sugar esters was possible, through chemical catalysis, using H2O2 and K2S2O8 as initiators, at 60°C, for 24 hours. IR spectra of lhe monomers and respective polymers were compared revealing lhe disappearance of lhe vinyl group in lhe polymer spectra. The molar weights of lhe polymers were determined by GPC and presented lhe following results: poly (5-0-vinyladipoyl L-arabinose): Mw = 7.2 X 104; PD = 2.48; poly (6-0-vinyladipoyl D-glucose): Mw = 2.7 X 103; PD = 1.75 and poly (1'-O-vinyladipoyl sucrose): Mw = 4.2 X 104; PD = 6.57. The six sugar esters were submitted to superficial tension tests for determination of the critical micelle concentrations (CMC), which varied from 122 to 167 ppm. Finally, a study of applicability of these sugar esters, as lubricants for completion fluids of petroleum wells was' accomplished through comparative analysis of lhe efficiency of these sugar esters, in relation to three commercial lubricants. The products synthesized in this thesis presented equivalent or superior action to lhe tested commercial products

Aplicação do escore MELD em pacientes submetidos a transplante de fígado: análise retrospectiva da sobrevida e dos fatores preditivos a curto e longo prazo

BACKGROUND: The model for end-stage liver disease (MELD) was developed to predict short-term mortality in patients with cirrhosis. There are few reports studying the correlation between MELD and long-term posttransplantation survival. AIM: To assess the value of pretransplant MELD in the prediction of posttransplant survival. METHODS: The adult patients (age >18 years) who underwent liver transplantation were examined in a retrospective longitudinal cohort of patients, through the prospective data base. We excluded acute liver failure, retransplantation and reduced or split-livers. The liver donors were evaluated according to: age, sex, weight, creatinine, bilirubin, sodium, aspartate aminotransferase, personal antecedents, brain death cause, steatosis, expanded criteria donor number and index donor risk. The recipients' data were: sex, age, weight, chronic hepatic disease, Child-Turcotte-Pugh points, pretransplant and initial MELD score, pretransplant creatinine clearance, sodium, cold and warm ischemia times, hospital length of stay, blood requirements, and alanine aminotransferase (ALT >1,000 UI/L = liver dysfunction). The Kaplan-Meier method with the log-rank test was used for the univariable analyses of posttransplant patient survival. For the multivariable analyses the Cox proportional hazard regression method with the stepwise procedure was used with stratifying sodium and MELD as variables. ROC curve was used to define area under the curve for MELD and Child-Turcotte-Pugh. RESULTS: A total of 232 patients with 10 years follow up were available. The MELD cutoff was 20 and Child-Turcotte-Pugh cutoff was 11.5. For MELD score > 20, the risk factors for death were: red cell requirements, liver dysfunction and donor's sodium. For the patients with hyponatremia the risk factors were: negative delta-MELD score, red cell requirements, liver dysfunction and donor's sodium. The regression univariated analyses came up with the following risk factors for death: score MELD > 25, blood requirements, recipient creatinine clearance pretransplant and age donor >50. After stepwise analyses, only red cell requirement was predictive. Patients with MELD score < 25 had a 68.86%, 50,44% and 41,50% chance for 1, 5 and 10-year survival and > 25 were 39.13%, 29.81% and 22.36% respectively. Patients without hyponatremia were 65.16%, 50.28% and 41,98% and with hyponatremia 44.44%, 34.28% and 28.57% respectively. Patients with IDR > 1.7 showed 53.7%, 27.71% and 13.85% and index donor risk <1.7 was 63.62%, 51.4% and 44.08%, respectively. Age donor > 50 years showed 38.4%, 26.21% and 13.1% and age donor <50 years showed 65.58%, 26.21% and 13.1%. Association with delta-MELD score did not show any significant difference. Expanded criteria donors were associated with primary non-function and severe liver dysfunction. Predictive factors for death were blood requirements, hyponatremia, liver dysfunction and donor's sodium. CONCLUSION: In conclusion MELD over 25, recipient's hyponatremia, blood requirements, donor's sodium were associated with poor survival.

Conseqüências da análise incorreta de experimentos blocados

Errors are always present in experimental measurements so, it is important to identify them and understand how they affect the results of experiments. Statistics suggest that the execution of experiments should follow random order, but unfortunately the complete randomization of experiments is not always viable for practical reasons. One possible simplification is blocked experiments within which the levels of certain factors are maintained fixed while the levels of others are randomized. However this has a cost. Although the experimental part is simplified, the statistical analysis becomes more complex.

O estado da arte da cromatografia associada à espectrometria de massas acoplada à espectrometria de massas na análise de compostos tóxicos em alimentos

Chromatography combined with several different detection systems is one of the more used and better performing analytical tools. Chromatography with tandem mass spectrometric detection gives highly selective and sensitive analyses and permits obtaining structural information about the analites and about their molar masses. Due to these characteristics, this analytical technique is very efficient when used to detect substances at trace levels in complex matrices. In this paper we review instrumental and technical aspects of chromatography-tandem mass spectrometry and the state of the art of the technique as it is applied to analysis of toxic substances in food.

Alteração da atividade enzimática em organismos aquáticos por poluentes de origem agrícola: uma abordagem geral e sobre a suscetibilidade da fosfatase ácida

The input of agrochemicals in the aquatic compartment can results in biochemical injuries for living organisms. In this context, the knowledge of alterations of enzymatic activities due the presence of agriculture pollutants contributes for the elucidation of the mechanisms of toxicity, implementation of economic methods for monitoring purposes and establishment of maximum allowed concentrations. In the present work, the above considerations are discussed, and data concerning changes in enzymatic function by pesticides and fertilizer contaminants are reviewed. Also, we focused on the acid phosphatase due its susceptibility to several pollutants and diversity in cellular functions.

Validação e estimativa da incerteza de método para análise de licopeno e β-caroteno em polpa de tomate por cromatografia líquida de alta eficiência

A method to quantify lycopene and β-carotene in freeze dried tomato pulp by high performance liquid chromatography (HLPC) was validated according to the criteria of selectivity, sensitivity, precision and accuracy, and uncertainty estimation of measurement was determined with data obtained in the validation. The validated method presented is selective in terms of analysis, and it had a good precision and accuracy. Detection limit for lycopene and β-carotene was 4.2 and 0.23 mg 100 g-1, respectively. The estimation of expanded uncertainty (K = 2) for lycopene was 104 ± 21 mg 100 g-1 and for β-carotene was 6.4 ± 1.5 mg 100 g-1.

Experimento didático de quimiometria para análise exploratória de óleos vegetais comestíveis por espectroscopia no infravermelho médio e análise de componentes principais: um tutorial, parte I

This manuscript aims to show the basic concepts and practical application of Principal Component Analysis (PCA) as a tutorial, using Matlab or Octave computing environment for beginners, undergraduate and graduate students. As a practical example it is shown the exploratory analysis of edible vegetable oils by mid infrared spectroscopy.