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Produção de etanol a partir da fração hemicelulósica do bagaço de cana usando glicose isomerase coimobilizada com Saccharomyces cerevisiae
(Universidade Federal de São Carlos, 2014-04-23) Silva, Claudia Ramos da; Giordano, Raquel de Lima Camargo; https://lattes.cnpq.br/1597673343693376
Glucose isomerase (GI) was covalently immobilized and co-immobilized with baker yeast in calcium alginate beads for ethanol production by simultaneous isomerization and fermentation of xylose or hemicellulose hydrolysate from bagasse. GI was covalently immobilized on glutaraldehyde-chitosan and high protein loads were immobilized (30-68 support mg.g-1). High immobilization yields (100%) and activity recovery (90%) were achieved. Under typical operation conditions of simultaneous isomerization and fermentation (pH 5, 35°C, medium with nutrients and ethanol concentrations up to 70g.L-1) the derivative remained 90% of initial activity after 120 hours. Calcium carbonate was used to maintain the pH in isomerization/fermentation medium higher than 5.0, ensuring high conversion of xylose at 32- 35°C. Accordingly, concentrations of enzyme and yeast in the reactor of 60-120.103UI.L-1 and 50g.L-1, respectively, resulted in better yields and selectivity for ethanol batch production. After consumption of ~ 65g.L-1 of xylose in about 12 hours, 21g.L-1 of ethanol and 14g.L-1 of xylitol was produced. In a medium without calcium carbonate, partial sugar conversion was observed due to the reduction of pH medium, which decreased up to 4.7, causing the inactivation of GI. The treatment of sugarcane bagasse with diluted acid resulted in hydrolysate with 61.0g. L-1 of xylose, 7.3g.L-1 of arabinose, 7.2g.L-1 of glucose, 10.4g.L-1 of acetic acid, 0.53g.L-1 of furfural, 0.06g.L-1 of hydroxymethylfurfural and 4.3g.L-1 of lignin derivatives. Baker yeast was able to produce ethanol from non-detoxified liquid hydrolysate as efficiently as pure xylose medium. Simultaneous isomerization and fermentation using non-detoxified hydrolysate led to 23 g.L-1 ethanol, yield of 0.34g.g-1 and a productivity of 1.8g.L-1.h-1. Continuous process was conducted for 7 days. The operation for longer periods of time will be possible with pH control and microbial contamination prevention.
Complexos de rutênio (II) de interesse biológico: avaliação in vitro e in vivo do potencial antitumoral e genotóxico
(Universidade Federal de São Carlos, 2014-04-23) Souza, Andréa Prado Carnizello; Batista, Alzir Azevedo; https://lattes.cnpq.br/6469642481998660; https://lattes.cnpq.br/8986638381625450
This work evaluated ruthenium (II) complexes in biological assays in vitro on tumor cells and non-tumor, and in vivo in male Swiss and C57BL/6 mice, as well as the interactions with DNA and BSA were evaluated. The compounds (1) [Ru(dppb)(SpyMe2-N,S)2]; (2) [RuCl (SpyMe2-N,S)2NO]; (3) [Ru(Pic)2(dppb)]; (4) [Ru(Gly)(dppb)(4,4'-mebipy)]PF6; (5) [Ru(Gly)(dppb)(phen)]PF6; (6) [Ru(Tyr)(dppb)(4,4'-mebipy)]PF6; (7) [Ru(Tyr)(dppb)(phen)] PF6; (8) [Ru(Trp) (dppb)(phen)]PF6 and (9) ct-[RuCl(CO)(dppb)(bipy) ]PF6 (where, dppb = 1,4-bis (diphenylphosphino) butane; pic = picolinate; SpyMe2 = 4,6-dimethyl-2- mercaptopyrimidine, 4,4'-mebipy = 4,4'-dimethyl-2, 2'-bipyridine; phen = phenanthroline; Gly = glycine, Tyr = tyrosine, Trp = tryptophan; bipy = 2,2'- bipyridine) underwent a screening evaluation of cytotoxic activity on different tumor cell lines U251, HeLa, MCF7, HepG2 , MO59J and B16F10 and non tumour V79, in different concentrations by XTT method. The compound 9 was selected for the assessment of interactions with DNA and BSA, the genotoxic potential in vitro (V79 and HepG2 cells), in vivo (Swiss mice), as well as to evaluate the antitumor potential in vivo (C57BL/6 mice). In vitro experiments, the compoud 9 was assessed at various concentrations in the tests of interactions with DNA and BSA and micronucleus test. In vivo experiments, animals were treated with different doses of the compound 9 by intraperitoneal route in the micronucleus and comet assays, and subcutaneous route in the evaluating of the antitumoral potential. The micronucleus test in bone marrow and comet in hepatocytes were employed to study the potential genotoxic. For both assays, in vitro and in vivo, groups negative controls (water) and positive (methyl methanesulfonate and cisplatin) were included. The results of in vitro cytotoxicity assays showed that the HeLa and MCF7 tumor cells were sensitive to the majority of the complexes evaluated. However, the compound 9 showed cytotoxicity against all tumor cell lines evaluated, with low IC50 values. In the experiments of interaction with DNA and BSA, the compound 9 showed weak interactions with DNA and hydrophobic interactions for BSA. The results obtained in vitro micronucleus tests for complex 9 showed absence of genotoxicity in V79 cells and in HepG2 tumor cells showed up genotoxic at a concentration of 1.25 μmol L-1. In experiments in vivo micronucleus, the compound 9 was not genotoxic in different doses evaluated. Regarding the comet assay, the results showed an increased frequency of DNA damage in hepatocytes in a dose of 5.0 mg kg-1 b.w. In vivo antitumor test, animals treated with 5.0 mg kg-1 b.w. of compound 9, showed significant inhibition of tumor growth compared to untreated control. In the histopathological analysis, the compound 9 also showed significant inhibition of mitosis in relation to the control group. Most of the compounds evaluated in this study showed in vitro cytotoxic activity on tumor cells, especially in MCF7 cells. The compound 9 showed promising results in biological in vitro and in vivo assays, suggesting that this compound may be potential candidate for chemotherapy in cancer treatment.
Distribuição de Poisson bivariada aplicada à previsão de resultados esportivos
(Universidade Federal de São Carlos, 2014-04-23) Silva, Wesley Bertoli da; Salasar, Luis Ernesto Bueno; https://lattes.cnpq.br/5464564215528609; https://lattes.cnpq.br/7852733762870256
The modelling of paired counts data is a topic that has been frequently discussed in several threads of research. In particular, we can cite bivariate counts, such as the analysis of sports scores. As a result, in this work we present the bivariate Poisson distribution to modelling positively correlated scores. The possible independence between counts is also addressed through the double Poisson model, which arises as a special case of the bivariate Poisson model. The main characteristics and properties of these models are presented and a simulation study is conducted to evaluate the behavior of the estimates for different sample sizes. Considering the possibility of modeling parameters by insertion of predictor variables, we present the structure of the bivariate Poisson regression model as a general case as well as the structure of an effects model for application in sports data. Particularly, in this work we will consider applications to Brazilian Championship Serie A 2012 data, in which the effects will be estimated by double Poisson and bivariate Poisson models. Once obtained the fits, the probabilities of scores occurence are estimated and then we obtain forecasts for the outcomes. In order to obtain more accurate forecasts, we present the weighted likelihood method from which it will be possible to quantify the relevance of the data according to the time they were observed.
Impactos da taxa de juros do crédito rural nas demandas por insumos agrícolas
(Universidade Federal de São Carlos, 2014-04-23) Gurgel, Gustavo Sawaya Amaral; Castro, Eduardo Rodrigues de; https://lattes.cnpq.br/5702172673123334; https://lattes.cnpq.br/4266290412218984; Gomes, Alexandre Lopes; http://lattes.cnpq.br/5002157193962189; Spolador, Humberto Francisco Silva; http://lattes.cnpq.br/1699973266697060
Rural credit was implemented in Brazil with the intention of accelerating the process of modernization of agriculture and provides capital for funding, investment and commercialization of agricultural production, it has been offered at rates below market rates. The subsidized interest rates are the main attraction of rural credit and strengthen its importance in agriculture as a financing instrument. But problems such as the concentration of resources in producers with higher income, access to credit and capital substitution may compromise the effectiveness of the credit in their purposes. Some studies have reported positive impacts of rural credit in supply and producers income as well as in demand for agricultural inputs. Given the importance of the agricultural sector and considering all the problems associated with credit, is questioned what impact the rural credit demands in agricultural inputs. The work is based on the theory of the firm in competitive markets, assuming that the producer faces restrictions on the purchase of inputs and minimizes the production cost given a production level. From the minimum cost function derive the conditional demands of inputs, which can be influenced by the availability of credit and its interest rate. In the empirical analysis Transcendental Logarithmic (Translog) function was used, that assumes no restrictions on the relationship between the inputs a priori.
Nucleação, crescimento de cristais, relaxação e escoamento viscoso em vidros de diopsídio e diborato de lítio
(Universidade Federal de São Carlos, 2014-04-23) Cassar, Daniel Roberto; Zanotto, Edgar Dutra; https://lattes.cnpq.br/1055167132036400; https://lattes.cnpq.br/1717397276752482
Heated glasses undergo a variety of kinetic processes, such as crystallization, relaxation and viscous flow, that are very important both scientifically and technologically. In this work, we measured and rigorously analyzed these processes according to several models and theories, for two glass compositions: diopside (CaO MgO 2 SiO2) and lithium diborate (Li2O 2 B2O3). These analyses addressed the following questions: which viscosity model better describes the experimental data? Which viscosity model better describes the structural relaxation kinetics bellow the glass transition temperature? Does the decoupling between crystallization and viscous flow kinetics occur for the studied materials, as reported in the literature for lithium disilicate? The results showed that the MYEGA viscosity model described well both viscous flow and structural relaxation data. Moreover, our results point towards an explanation for the breakdown between crystallization and viscous flow kinetics: it is a phenomenon in which the crystal growth structural units are able to move without cooperative rearrangements if the viscosity is above 5,6(6) 103 Pa s. With our results for lithium diborate, we confirmed Kauzmann s resolution for his own paradox: this glass fully crystallizes before achieving a metastable equilibrium state when kept at the Kauzmann s temperature. This means that such glass cannot undergo the ideal glass transition . These findings are useful for technological processes such as glass annealing, new glass-ceramic microstructure design, and glass making.