Adsorption of amyloglucosidase from Aspergillus niger NRRL 3122 using ion exchange resin

Amyloglucosidase enzyme was produced by Aspergillus niger NRRL 3122 from solid-state fermentation, using deffated rice bran as substrate. The effects of process parameters (pH, temperature) in the equilibrium partition coefficient for the system amyloglucosidase - resin DEAE-cellulose were investigated, aiming at obtaining the optimum conditions for a subsequent purification process. The highest partition coefficients were obtained using 0.025M Tris-HCl buffer, pH 8.0 and 25ºC. The conditions that supplied the highest partition coefficient were specified, the isotherm that better described the amyloglucosidase process of adsorption obtained. It was observed that the adsorption could be well described by Langmuir equation and the values of Qm and Kd estimated at 133.0 U mL-1 and 15.4 U mL-1, respectively. From the adjustment of the kinetic curves using the fourth-order Runge-Kutta algorithm, the adsorption (k1) and desorption (k2) constants were obtained through optimization by the least square procedure, and the values calculated were 2.4x10-3 mL U-1 min-1 for k1 and 0.037 min-1 for k2 .

Isotermas de dessorção de filé de bonito (Sarda sarda) desidratado osmoticamente e defumado

O presente trabalho teve como objetivo a obtenção de isotermas de dessorção de filés de bonito (Sarda sarda), previamente salgados a vácuo e defumados com fumaça líquida. As isotermas foram obtidas a quatro temperaturas (5, 25, 40 e 60 ºC) em condições de dessorção, através do método gravimétrico estático, com soluções salinas saturadas. Os dados experimentais foram ajustados a quatro modelos da literatura (BET linearizado, GAB, Henderson e Oswin modificado). Os resultados mostraram que as isotermas tomaram forma sigmoidal de tipo II e que o modelo de Guggenheim-Anderson-deBoer (GAB) foi aceitável para modelar os dados experimentais. O calor isostérico de dessorção, um parâmetro necessário para simular e projetar adequadamente o secador, também foi calculado e pode ser representado através de um modelo matemático simples, em função da umidade de equilíbrio.

Time evolution of the South Atlantic Magnetic Anomaly

The South Atlantic Magnetic Anomaly (SAMA) is one of the most outstanding anomalies of the geomagnetic field. The SAMA secular variation was obtained and compared to the evolution of other anomalies using spherical harmonic field models for the 1590-2005 period. An analysis of data from four South American observatories shows how this large scale anomaly affected their measurements. Since SAMA is a low total field anomaly, the field was separated into its nondipolar, quadrupolar and octupolar parts. The time evolution of the non-dipole/total, quadrupolar/total and octupolar/total field ratios yielded increasingly high values for the South Atlantic since 1750. The SAMA evolution is compared to the evolution of other large scale surface geomagnetic features like the North and the South Pole and the Siberia High, and this comparison shows the intensity equilibrium between these anomalies in both hemispheres. The analysis of non-dipole fields in historical period suggests that SAMA is governed by (i) quadrupolar field for drift, and (ii) quadrupolar and octupolar fields for intensity and area of influence. Furthermore, our study reinforces the possibility that SAMA may be related to reverse fluxes in the outer core under the South Atlantic region.

Kelp gulls, Larus dominicanus (Aves: Laridae), breeding in Keller Peninsula, King George Island, Antarctic Peninsula

We examined the distribution, abundance and density of the Kelp Gull, Larus dominicanus (Lichtenstein, 1823), at Keller Peninsula on two occasions during the breeding season of 2007-2008 (once for incubation and once for chick stages) and compared our results with previously published data. We present information on the number of eggs, incubation success, and initial development of L. dominicanus chicks in the studied sites. The abundance and density of the species has remained statistically similar in Keller Peninsula over the last 30 years (since 1978-1979). Although the abundance and density were almost unchanged, we recorded alterations in the occupation of the breeding areas by L. dominicanus, mainly the abandonment of breeding sites in the eastern portion of Keller Peninsula. The results of the present study compared with similar previous investigations on the abundance of L. dominicanus indicate that the populations have been in equilibrium over the years.

Late Quaternary drainage dynamics in northern Brazil based on the study of a large paleochannel from southwestern Marajó Island

Marajó Island shows an abundance of paleochannels easily mapped in its eastern portion, where vegetation consists mostly of savannas. SRTM data make possible to recognize paleochannels also in western Marajó, even considering the dense forest cover. A well preserved paleodrainage network from the adjacency of the town of Breves (southwestern Marajó Island) was investigated in this work combining remote sensing and sedimentological studies. The palimpsest drainage system consists of a large meander connected to narrower tributaries. Sedimentological studies revealed mostly sharp-based, fining upward sands for the channelized features, and interbedded muds and sands for floodplain areas. The sedimentary structures and facies successions are in perfect agreement with deposition in channelized and floodplain environments, as suggested by remote sensing mapping. The present study shows that this paleodrainage was abandoned during Late Pleistocene, slightly earlier than the Holocene paleochannel systems from the east part of the island. Integration of previous studies with the data available herein supports a tectonic origin, related to the opening of the Pará River along fault lineaments. This would explain the disappearance of large, north to northeastward migrating channel systems in southwestern Marajó Island, which were replaced by the much narrower, south to southeastward flowing modern channels.

Remoção de Pb2+ e Cr3+ em solução por zeólitas naturais associadas a rochas eruptivas da formação serra geral, bacia sedimentar do Paraná

The capacity of natural zeolites and its host rock (dacite) to remove Pb2+ and Cr3+ from aqueous solutions has been investigated. Results showed that both samples prefer to remove Pb2+ instead of Cr3+. Almost 100% of Pb2+ was removed from solutions with concentration until 50 mg L-1 and 100 mg L-1 of this metal, respectively by dacite and zeolite. The equilibrium of metals adsorption process was reached during the first 30 min by both materials. Na+ can be used to recover Pb2+, but not to remove Cr3+ from the treated samples. The Sips model showed a good fit for experimental data of this study.

Hidróxidos duplos lamelares: nanopartículas inorgânicas para armazenamento e liberação de espécies de interesse biológico e terapêutico

Studies about the inorganic nanoparticles applying for non-viral release of biological and therapeutic species have been intensified nowadays. This work reviews the preparation strategies and application of layered double hydroxides (LDH) as carriers for storing, carrying and control delivery of intercalated species as drugs and DNA for gene therapy. LDH show low toxicity, biocompatibility, high anion exchange capacity, surface sites for functionalization, and a suitable equilibrium between chemical stability and biodegradability. LDH can increase the intercalated species stability and promote its sub-cellular uptake for biomedical purposes. Concerning the healthy field, LDH have been evaluated for clinical diagnosis as a biosensor component.

I2: uma molécula didática

Iodine vapor is a very suitable substance to learn about molecular energy levels and transitions, and to introduce spectroscopic techniques. As a diatomic molecule its spectra are relatively simple and allow straightforward treatment of the data leading to the potential energy curves and to quantum mechanics concepts. The overtone bands, in the resonance Raman scattering, and the band progressions, in the electronic spectra, play an important role in the calculation of the Morse potential curves for the fundamental and excited electronic state. A weaker chemical bond in the electronic excited state, compared to the fundamental state, is evidenced by the increase in the equilibrium interatomic distance. The resonance Raman scattering of I2 is highlighted due to its importance for obtaining the anharmonicity constant in the fundamental electronic state.

Enzymatic kinetic resolution of (RS)-1-(Phenyl)ethanols by Burkholderia cepacia lipase immobilized on magnetic nanoparticles

Lipase from Burkholderia cepacia immobilized on superparamagnetic nanoparticles using adsorption and chemisorption methodologies was efficiently applied as recyclable biocatalyst in the enzymatic kinetic resolution of (RS)-1-(phenyl)ethanols via transesterification reactions. (R)-Esters and the remaining (S)-alcohols were obtained with excellent enantiomeric excess (> 99%), which corresponds to a perfect process of enzymatic kinetic resolution (conversion 50%, E > 200). The transesterification reactions catalysed with B. cepacia lipase immobilized by the glutaraldehyde method showed the best results in terms of reusability, preserving the enzyme activity (conversion 50%, E > 200) for at least 8 successive cycles.

A Equação-Mestra: atingindo o equilíbrio

In the last years, a great interest in nonequilibrium systems has been witnessed. Although the Master Equations are one of the most common methods used to describe these systems, the literature about these equations is not straightforward due to the mathematical framework used in their derivations. The goals of this work are to present the physical concepts behind the Master Equations development and to discuss their basic proprieties via a matrix approach. It is also shown how the Master Equations can be used to model typical nonequilibrium processes like multi-wells chemical reactions and radiation absorption processes.

Headland-bay beach planform stability of Santa Catarina State and of the Northern Coast of São Paulo State

This paper presents the results of the planform stability classification for the headland-bay beaches of the State of Santa Catarina and of the Northern Coast of São Paulo, based on the application of the Parabolic Bay-Shape Equation (PBSE) to aerial images of the beaches, using the software MEPBAY®. For this purpose, georeferenced mosaics of the QuickBird2® satellite imagery (for the State of Santa Catarina) and vertical aerial photographs (for the northern coast of São Paulo State) were used. Headland-bay beach planform stability can be classified as: (1) in static equilibrium, (2) in dynamic equilibrium, (3) unstable or (4) in a state of natural beach reshaping. Static equilibrium beaches are the most frequent along the coast of the State of Santa Catarina and the Northern Shore of São Paulo, notably along the most rugged sectors of the coast and those with experiencing lower fluvial discharge. By comparison, dynamic equilibrium beaches occur primarily on the less rugged sectors of the coast and along regions with higher fluvial discharge. Beaches in a state of natural beach reshaping have only been found in SC, associated with stabilized estuarine inlets or port breakwaters. However, it is not possible to classify any of these beaches as unstable because only one set of images was used. No clear relation was observed between a beach's planform stability and other classification factors, such as morphodynamics or orientation.

Programa de Controle da Doença de Chagas no Estado de São Paulo: aspectos sorológicos e entomológicos de inquéritos entre escolares de ensino fundamental

Como parte de avaliação de medidas de controle de vetores, levadas a efeito no Estado de São Paulo, na década de 60, inquéritos sorológicos entre crianças escolares nascidas após sua aplicação foram realizados nos períodos abrangidos entre os anos 1968 e 1970, em todos os municípios do estado, à exceção dos da Grande São Paulo e, anualmente, de 1973 a 1983, em amostra selecionada a partir daqueles com as maiores soroprevalências para a infecção chagásica. No primeiro caso, a metodologia sorológica previu os exames à base da reação de fixação de complemento, em soros e, no segundo, a reação de imunofluorescência indireta, em eluatos de sangue total absorvido em papel-filtro. Presença de triatomíneos e sua condição de infecção por Trypanosoma cruzi, coligidas nos diversos municípios de acordo com o ano dos nascimentos dos escolares e da realização dos inquéritos, permitiram vislumbrar o quadro da infecção chagásica no Estado de São Paulo, naquelas épocas. A região de Sorocaba destacou-se das demais em termos sorológicos, sustentada pela presença do Triatoma infestans até o início da década de 70. Similarmente, a autoctonia dos casos foi aí observada de maneira preponderante, enquanto que em outras regiões do estado manteve-se um equilíbrio entre casos autóctones e importados. A análise dos dados revela que, ainda em 1974, a transmissão vetorial poderia registrar-se no estado. É importante destacar que, mesmo com falhas de cobertura, até o ano de 1997, não se observou mais sororreatividade para infecção chagásica nas idades inferiores a 15 anos, no Programa de Controle do Estado de São Paulo.

Ortorexia nervosa: reflexões sobre um novo conceito

Ortorexia nervosa é o termo descrito para o comportamento obsessivo patológico caracterizado pela fixação por saúde alimentar. O quadro ainda não foi oficialmente reconhecido como um transtorno alimentar, mas discute-se o conceito, suas características, interações e sintomas. No presente trabalho foi realizada uma revisão dos vinte e um artigos publicados desde 1997, quando o comportamento da ortorexia nervosa foi inicialmente descrito. Foram apontadas semelhanças e diferenças entre o comportamento alimentar observado na ortorexia nervosa e nos transtornos alimentares mais frequentes (anorexia e bulimia nervosa). Um instrumento foi desen-volvido e validado para detecção do quadro ortoréxico. Os estudos apontam alguns grupos vulneráveis à orto-rexia nervosa: estudantes de medicina, médicos, nutricionistas, pessoas com sintomas de ansiedade, obsessivo-compulsivos e aqueles que supervalorizam o corpo perfeito. A ortorexia nervosa é situada a partir de uma análise dos conceitos de atitude alimentar e alimentação saudável, procurando um foco biopsicossocial para a alimentação adequada e não apenas um foco fisiológico. Não existem estudos investigativos sobre a ortorexia nervosa no Brasil, mas o tema deve ser discutido para alertar os profissionais da área da saúde sobre a existência desse comportamento inadequado e suas possíveis consequências não só para a saúde física e emocional, mas também para a visão de alimentação saudável.

Nutraceuticals in reproduction of bulls and stallions

The industry has made available in the market a series of substances (nutraceuticals) which intent would be to optimize the use of nutrients in some metabolic paths, influencing positively reproductive performance in animals. However, the response to the use of nutraceuticals varies according to the animal. As the organism is highly complex and in order to achieve a perfect activity of the hypothalamic-pituitary-gonadal axis, an ideal interaction in molecular basis is needed, where the nutraceuticals can have their direct action. The aim of this study was to review the function and research results using the main nutraceuticals (β carotene, vitamin A, L-carnitine, omegas 3, 6 and 9 and Gamma-oryzanol) on reproductive characteristics of bulls and stallions.

Produção in vitro de embriões de ovinos: uma visão crítica do método e de seu resultado a campo

A metodologia de produção in vitro de embriões de ovinos implica no desenvolvimento de meios de maturação, fertilização e cultivo que permitam aumentar a taxa de clivagem e desenvolvimento, tanto para o investimento biotecnológico em programas comerciais, quanto para sua utilização em clonagem e transgenia dessa espécie animal. Do ponto de vista da pesquisa, os ovócitos podem ser obtidos pelas técnicas de punção e slicing a partir de ovários oriundos de matadouros, ou através de aspiração folicular por laparoscopia. Como vantagem, este método permite o uso de uma mesma doadora estimulada hormonialmente em intervalos periódicos, mantida sob rigoroso controle sanitário, o que é de vital importância para a produção de biofármacos em programas que utilisem os ovinos como modelo biológico. Por outro lado, em nosso país a demanda pela multiplicação de animais de alto valor genético, seja pela produtividade ou pelo elevado valor comercial dos mesmos, impõe o desenvolvimento, adaptação e otimização das diferentes metodologias desenvolvidas ao longo dos ultimos anos em laboratórios de referência mundiais. Nesse contexto, cresce de importância o perfeito conhecimento da fisiologia dessa espécie e das raças criadas em nosso país, e da problemática da produção in vitro de seus embriões. Respeitando essas premissas, gerar o desenvolvimento de protocolos que permitam não apenas aumentar a população de ovócitos passíveis de maturação in vitro, mas de sua competência ao desenvolvimento ao estágio de blastocisto, ou, alternativamente, sua transferência a receptoras em estágios precoces do desenvolvimento, evitando assim as conhecidas perdas durante o desenvolvimento in vitro, e o baixo percentual de gestações que chegam a termo, com cordeiro saudáveis. Trata-se de um desafio, que já apresenta os primeiros resultados em nosso país, tanto na produção comercial de embriões produzidos in vitro, quanto em programas de clonagem e transgenia.