Sucrose utilization by Zymomonas mobilis: Levan production optimization using submerged fermentation

Levan is an extracellular polysaccharide (EPS), constituted by linked fructose units β (2,6), obtained by transfructosilation reaction during fermentation of microorganisms in a sucrose rich culture medium. The bacterial levan production is a good alternative of fructose source, besides having certain functional characteristics in the human body, such as a hypocholesterolemic and an anticarcinogenic agent. In the food industry, the levan can be used to fix colors and flavors, as well as to thickening and stabilizing agent in foods. This work aimed to analyze the kinetic parameters for levan production by Zymomonas mobilis CCT 4494, using submerged fermentation. The response surface methodology (RSM), was utilized to predict the optimization of medium for exopolymer production and the independent variables studied were: initial pH, incubation temperature, sucrose, KCl, K2SO4, MgSO4 and CaCl2. It was observed that the bacterium Z. mobilis CCT 4494 well adapted in medium containing high concentrations of sucrose.

A fuzzy Lyapunov function approach for stabilization and control of switched TS fuzzy systems

In this work, sufficient conditions for the existence of switching laws for stabilizing switched TS fuzzy systems via a fuzzy Lyapunov function are proposed. The conditions are found by exploring properties of the membership functions and are formulated in terms of linear matrix inequalities (LMIs). Stabilizing switching conditions with bounds on the decay rate solution and H1 performance are also obtained. Numerical examples illustrate the effectiveness of the proposed design methods.

Efeitos das condições neuromotoras da paralisia cerebral no sentido háptico durante tarefas de controle postural

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Diversidade de algas verdes em crostas biológicas de solo do cerrado

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

Production of exopolysaccharide from rhizobia with potential biotechnological and bioremediation applications

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

Spermatozoon ultrastructure and semen parameters of Brycon vermelha (Characiformes, Characidae)

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

Synergy between polyaniline and OMt clay mineral in Langmuir-Blodgett films for the simultaneous detection of traces of metal ions

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

Compressible modes in a square lid-driven cavity

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Methicillin resistance in Staphylococcus aureus and coagulase-negative staphylococci: Epidemiological and molecular aspects

Infections caused by the genus Staphylococcus are of great importance for human health. Staphylococcus species are divided into coagulase-positive staphylococci, represented by S. aureus, a pathogen that can cause infections of the skin and other organs in immunocompetent patients, and coagulase-negative staphylococci (CNS) which comprise different species normally involved in infectious processes in immunocompromised patients or patients using catheters. Oxacillin has been one of the main drugs used for the treatment of staphylococcal infections; however, a large number of S. aureus and CNS isolates of nosocomial origin are resistant to this drug. Methicillin resistance is encoded by the mecA gene which is inserted in the SCCmec cassette. This cassette is a mobile genetic element consisting of five different types and several subtypes. Oxacillin-resistant strains are detected by phenotypic and genotypic methods. Epidemiologically, methicillin-resistant S. aureus strains can be divided into five large pandemic clones, called Brazilian, Hungarian, Iberian, New York/Japan and Pediatric. The objective of the present review was to discuss aspects of resistance, epidemiology, genetics and detection of oxacillin resistance in Staphylococcus spp., since these microorganisms are increasingly more frequent in Brazil.

Electromyographic study of the longissimus dorsi and iliocostalis lumborum muscles during knee flexion and extension on a plain and on a tilt Roman table

The objective of this paper was to analyse the activity of the longissimus dorsi and the iliocostalis lumborum muscles--components of the erector spinae muscle--in order to determine: their action potentials during the use of a plain and a tilt Roman table; 2) to compare the action potentials of the two muscles; 3) to verify if the action potential of these two muscles remain constant during the arc of movement--knee flexion and extension--divided into angle ranges, and 4) to compare the action potentials of the muscles in movements performed in a free manner and against resistance. Twenty-three young volunteers were studied electromyographically and each muscle received a needle electrode (Mise) and a surface electrode. The results showed that the table model did not determine any difference in the action potential of the muscles and that, on average, the iliocostalis lumborum muscle developed a slightly higher action potential than the longissimus dorsi muscle during the free flexion of knees on the plain table. In more than 70% of the cases, there was no difference between the action potential of the muscles over the various angle ranges of knee flexion and extension. Relatively higher action potentials were recorded during knee flexion and extension against resistance than during the same movements performed in a free manner. This shows that the paravertebral musculature responds better to an overload (8 kg) imposed on the knee flexor group, confirming the stabilizing role of the longissimus dorsi and iliocostalis lumborum muscles during knee flexion and extension on a Roman table.

Direct effects of colchicine on myocardial function: studies in hypertrophied and failing spontaneously hypertensive rats

The aging spontaneously hypertensive rat (SHR) is a model in which the transition from chronic stable left ventricular hypertrophy to overt heart failure can be observed. Although the mechanisms for impaired function in hypertrophied and failing cardiac muscle from the SHR have been studied, none accounts fully for the myocardial contractile abnormalities. The cardiac cytoskeleton has been implicated as a possible cause for myocardial dysfunction. If an increase in microtubules contributes to dysfunction, then myocardial microtubule disruption by colchicine should promote an improvement in cardiac performance. We studied the active and passive properties of isolated left ventricular papillary muscles from 18- to 24-month-old SHR with evidence of heart failure (SHR-F, n=6), age-matched SHR without heart failure (SHR-NF, n=6), and age-matched normotensive Wistar-Kyoto rats (WKY, n=5). Mechanical parameters were analyzed before and up to 90 minutes after the addition of colchicine (10(-5), 10(-4), and 10(-3) mol/L). In the baseline state, active tension (AT) developed by papillary muscles from the WKY group was greater than for SHR-NF and SHR-F groups (WKY 5.69+/-1.47 g/mm2 [mean+/-SD], SHR-NF 3.41+/-1.05, SHR-F 2.87+/-0.26; SHR-NF and SHR-F P<0.05 versus WKY rats). The passive stiffness was greater in SHR-F than in the WKY and SHR-NF groups (central segment exponential stiffness constant, Kcs: SHR-F 70+/-25, SHR-NF 44+/-17, WKY 41+/-13 [mean+/-SD]; SHR-F P<0.05 versus SHR-NF and WKY rats). AT did not improve after 10, 20, and 30 minutes of exposure to colchicine (10(-5), 10(-4), and 10(-3) mol/L) in any group. In the SHR-F group, AT and passive stiffness did not change after 30 to 90 minutes of colchicine exposure (10(-4) mol/L). In summary, the data in this study fail to demonstrate improvement of intrinsic muscle function in SHR with heart failure after colchicine. Thus, in the SHR there is no evidence that colchicine-induced cardiac microtubular depolymerization affects the active or passive properties of hypertrophied or failing left ventricular myocardium.

Início de ativação muscular de estabilizadores primários e a capacidade física para avaliar estabilização lombo-pélvica

Introduction: Due to the high incidence of low back pain without apparent cause, different approaches to evaluate the lumbar instability has been proposed, such as surface electromyography to determine pre-activation and the ability of lumbar stabilization through functional physical assessment. In this context, the objective of this study was to evaluate the early activation of the primary stabilizing muscles in subjects without low back pain, with different physical abilities function (CFF). Method: Study participants were 20 subjects with 19.8 ± 1.4 years, 55.7 ± 8.8 kilos, 1.66 ± 0.08 m, of both sexes. The subjects underwent six Tests Physical Function (TFF) and the Test of Fast Moving Flexion Arm (TMRFB) to capture the electromyographic activity of the lumbar multifidus muscles (LM) and internal oblique - lower fibers (HI). Were assigned weights for each functional test and the result of the physical capacity of the final functional subject ranged from 0 to 100%. In the analysis of TMRB was considered the onset time of activation between the ML and HI. Results: Regarding TFF 2 (10%) subjects were considered to have normal physical capacity, 6 (30%) with good physical ability and 12 (60%) with regular physical capacity or poor. As for TMRFB average values of initiation of muscle activation in 75% of subjects were within the limits to characterize the condition of pre-muscle activation. Conclusion:The results obtained in the TFF were low compared with the CFF of asymptomatic subjects evaluated. This fact does not mean that the condition of stabilization of the subject is appropriate. However, the results obtained in the electromyographic examination to suggest that 25% of asymptomatic subjects tested did not have a proper condition of lumbar stabilization.

Biologia reprodutiva de Corecoris fuscus, Leptoglossus gonagra, L. zonatus e Sphictyrtus fasciatus (Heteroptera: Coreidae), com ênfase aos aspectos ultraestruturais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estabilização da fase perovskita e propriedades estruturais de filmes finos relaxores do sistema PLZT

Pós-graduação em Ciência dos Materiais - FEIS

Fresamento de aço para moldes e matrizes em condições criogênicas

Pós-graduação em Engenharia Mecânica - FEIS