Obtenção e caracterização de α-quitina e quitosanas de cascas de Macrobrachium rosembergii

The shells of Macrobrachium rosenbergii were submitted to deproteinization (Dp) and demineralization (Dm) aiming the extraction of α-chitin. The different parts of the shells were processed independently by carrying out sequence 1 (Dp/Dm) and sequence 2 (Dm/Dp). Both sequences allowed the extraction of chitins with low contents of calcium and magnesium, regardless of the part being processed. The sequence 1 lead to higher extraction yields while sequence 2 resulted in lower contents of inorganic compounds. Extensively deacetylated chitosans (GA<10%) of medium molecular weight (0,9 x 10(5) < Mv < 2 x 10(5) g/mol) resulted from the deacetylation of chitin.

Estado nutricional e adequação da ingestão de energia e nutrientes em pacientes com insuficiência cardíaca

FUNDAMENTO: Maior conhecimento sobre o estado nutricional e a ingestão de energia e nutrientes é necessário para auxiliar no tratamento de pacientes com insuficiência cardíaca (IC). OBJETIVO: Verificar o estado nutricional e analisar a adequação da ingestão de energia, macro e micronutrientes de pacientes com IC em atendimento ambulatorial. MÉTODOS: Foram coletados dados antropométricos e de ingestão alimentar habitual de 125 pacientes (72% homens, 52,1±9,8 anos, IMC 26,9±4,4 kg/m²). As variáveis antropométricas foram comparadas entre os sexos, e analisou-se a adequação da ingestão de energia e nutrientes perante as recomendações. RESULTADOS: Depleção ou risco de depleção das reservas musculares estava presente em 38,4% dos pacientes (associação com sexo masculino; p < 0,0001). Em 69,6% dos casos, a ingestão média de energia foi menor que as necessidades energéticas (p < 0,0001). Entre os micronutrientes analisados, magnésio, zinco, ferro e tiamina apresentaram prevalências de inadequação importantes, e a maioria dos pacientes teve consumo de cálcio e potássio abaixo da ingestão adequada e consumo de sódio acima. CONCLUSÃO: Pacientes ambulatoriais com IC apresentam depleção de reservas musculares, com ingestão inadequada de energia e diversos nutrientes. Não se observou associação significante entre quantidade de energia proveniente da dieta habitual e o estado nutricional. O acompanhamento multiprofissional deve ser estimulado para avaliar melhor o estado geral desses pacientes.

Adolescentes modelos de passarela: como é o consumo alimentar deste grupo?

OBJETIVO: Avaliar a adequação da ingestão de energia, macro e micronutrientes em adolescentes modelos de passarela. MÉTODOS: Estudo transversal de 33 adolescentes modelos e 33 não modelos, de 15 a 18 anos, pareadas por idade e índice de massa corpórea (IMC). A ingestão alimentar foi avaliada por meio de registro alimentar de três dias, sendo calculados os valores médios de energia, em kcal, os valores proporcionais dos macronutrientes em relação ao valor calórico total da dieta consumida, bem como os valores médios/medianos dos seguintes micronutrientes: cálcio, ferro, zinco, fósforo, magnésio, folato, vitamina D, vitamina C, vitamina A e vitamina E. RESULTADOS: Verificou-se que 24% das adolescentes do estudo apresentaram IMC abaixo dos valores mínimos para a idade. A média de ingestão de energia foi menor entre as modelos, em comparação às adolescentes não modelos (1.480,93±582,95 versus 1.973,00±557,63 kcal) (p<0,05). A ingestão de gorduras acima do recomendado foi semelhante entre os grupos - 30,3% das adolescentes modelos e 36,4% das adolescentes não modelos (p>0,05). O consumo inadequado de micronutrientes como o cálcio, ferro, zinco, magnésio, fósforo, vitaminas lipossolúveis, folato e ácido ascórbico ocorreu em ambos os grupos. CONCLUSÕES: A baixa ingestão energética (kcal) entre as modelos e a ingestão insuficiente de minerais e vitaminas alertam para que as agências de modelos comprometam-se com a saúde dessas adolescentes, garantindo um acompanhamento médico e nutricional.

Previsão de bitter pit em maçãs por meio da infiltração de Mg2+ e da aplicação de ethephon nos frutos

Estudou-se o efeito da infiltração de magnésio e cálcio no desenvolvimento de sintomas de bitter pit de maçãs 'Gala'. Examinou-se, também, a eficiência da infiltração de magnésio e da aceleração da maturação de maçãs 'Royal Gala' como métodos de previsão da ocorrência de bitter pit após o armazenamento. No primeiro experimento, maçãs 'Gala' foram infiltradas com MgCl2; CaCl2 ou MgCl2 mais CaCl2. No segundo experimento, maçãs 'Royal Gala' foram infiltradas com MgCl2; ou imersas em solução contendo ethephon por cinco minutos. Como controle, frutos de cada cultivar foram armazenados em atmosfera controlada por seis meses mais 18 dias a 20°C. Frutos infiltrados com MgCl2 apresentaram significativo acréscimo na incidência e severidade de bitter pit, proporcional à concentração de MgCl2 na solução. Frutos infiltrados com CaCl2 não apresentaram sintomas de bitter pit. A aceleração da maturação de maçãs 'Royal Gala' na colheita foi efetiva na previsão de bitter pit após o armazenamento.

Níveis de fósforo disponível e tamanho de partícula do fosfato bicálcico na dieta de poedeiras comerciais de 24 a 58 semanas de idade

Um experimento foi conduzido para verificar o efeito de níveis de fósforo e do tamanho de partícula do fosfato bicálcico na dieta de poedeiras comerciais na fase de produção. Utilizou-se um delineamento experimental inteiramente casualizado, em esquema fatorial 2 × 3 com dois tamanhos de partícula do fosfato (fino e granulado) e três níveis de fósforo disponível (0,28; 0,38 e 0,48%), totalizando seis tratamentos, cada um com cinco repetições de oito aves. As dietas experimentais foram isoproteicas, isocalóricas e isocálcicas. O consumo de ração, a produção de ovos, a massa de ovos, a conversão alimentar, a porcentagem de casca, a gravidade específica e os teores de cinzas, cálcio, fósforo e magnésio nos ossos não foram afetados pelas dietas. Dietas contendo fosfato bicálcico (fino ou granulado) e 0,28% de fósforo disponível atendem às exigências de fósforo de galinhas poedeiras semipesadas de 24 a 58 semanas de idade.

Fosfatos com diferentes relações flúor: fósforo na alimentação de frangos de corte

Um experimento foi conduzido com o objetivo de verificar os efeitos de diferentes relações flúor:fosforo na alimentação sobre o desempenho de frangos de corte. Foram utilizados 1.000 pintos de corte de 1 dia distribuídos em um delineamento inteiramente casualizado, com quatro tratamentos e cinco repetições de 50 aves por boxe. Os tratamentos consistiram de quatro fontes de fósforo com relações flúor:fósforo de 1:40, 1:60, 1:80 e 1:100. O experimento foi dividido em três fases experimentais: 1 a 21, 22 a 42 e 43 a 49 dias de idade. Em cada fase, avaliou-se o consumo de ração, o ganho de peso e a conversão alimentar. Ao final do experimento, foram abatidas duas aves de cada repetição para coleta da tíbia e de músculos do peito para análise das concentrações de flúor, cálcio, fósforo e magnésio desses tecidos. As relações flúor:fósforo avaliadas não afetaram o desempenho dos frangos de corte. A deposição óssea de flúor é proporcional à sua concentração na dieta, no entanto, a elevação dos níveis de flúor da dieta não influencia sua deposição nos músculos.

Prevalence of inadequate nutrient intake in a group of adolescents using dietary reference intake- based methods

O objetivo do presente estudo foi avaliar a prevalência de ingestão inadequada de nutrientes em um grupo de adolescentes de São Bernardo do Campo-SP. Dados de consumo de energia e nutrientes foram obtidos por meio de recordatórios de 24 horas aplicados em 89 adolescentes. A prevalência de inadequação foi calculada utilizando o método EAR como ponto de corte, após ajuste pela variabilidade intrapessoal, utilizando o procedimento desenvolvido pela Iowa State University. As Referências de Ingestão Dietética (IDR) foram os valores de referência para ingestão. Para os nutrientes que não possuem EAR estabelecida, a distribuição do consumo foi comparada com a AI. As maiores prevalências de inadequação em ambos sexos foram observadas para o magnésio (99,3 por cento para o sexo masculino e 81,8 por cento para o feminino), zinco (44,0 por cento para o sexo masculino e 23,5 por cento para o feminino), vitamina C (57,2 por cento para o sexo masculino e 59,9 por cento para o feminino) e folato (34,8 por cento para o sexo feminino). A proporção de indivíduos com ingestão superior à AI foi insignificante (menor que 2,0 por cento) em ambos os sexos

Influence of Annealing Heat Treatment and Cr, Mg, and Ti Alloying on the Mechanical Properties of High-Silicon Cast Iron

The influence of annealing on the mechanical properties of high-silicon cast iron for three alloys with distinct chromium levels was investigated. Each alloy was melted either with or without the addition of Ti and Mg. These changes in the chemical composition and heat treatment aimed to improve the material's mechanical properties by inhibiting the formation of large columnar crystals, netlike laminae, precipitation of coarse packs of graphite, changing the length and morphology of graphite, and rounding the extremities of the flakes to minimize the stress concentration. For alloys with 0.07 wt.% Cr, the annealing reduced the impact resistance and tensile strength due to an enhanced precipitation of refined carbides and the formation of interdendritic complex nets. Annealing the alloys containing Ti and Mg led to a decrease in the mechanical strength and an increase in the toughness. Alloys containing approximately 2 wt.% Cr achieved better mechanical properties as compared to the original alloy. However, with the addition of Ti and Mg to alloys containing 2% Cr, the chromium carbide formation was inhibited, impairing the mechanical properties. In the third alloy, with 3.5 wt.% of Cr additions, the mechanical strength improved. The annealing promoted a decrease in both hardness and amount of iron and silicon complex carbides. However, it led to a chromium carbide formation, which influenced the mechanical characteristics of the matrix of the studied material.

Anomalous thermodynamic properties in ferropericlase throughout its spin crossover transition

The thermodynamics properties of ferropericlase (Mg(1-x)Fe(x)O where x=0.1875) (Fp) throughout its spin crossover were investigated by first principles. Fp was treated as an ideal solid solution of pure high-spin and low-spin states. The Gibbs free energies of the pure states were addressed using the LDA+U method. A vibrational virtual-crystal model was developed to address the vibrational properties of the pure spin cases and used in conjunction with quasiharmonic theory to compute their vibrational free energies. The thermodynamics properties of Fp display significant anomalies that should be typical of spin crossover systems in general. In Fp, in particular, they are fundamental for understanding the state of earth's interior, where the pressure and temperature conditions of the crossover are realized.

Modification of composition of a nanoemulsion with different cholesteryl ester molecular species: Effects on stability, peroxidation, and cell uptake

Purpose: Use of lipid nanoemulsions as carriers of drugs for therapeutic or diagnostic purposes has been increasingly studied. Here, it was tested whether modifications of core particle constitution could affect the characteristics and biologic properties of lipid nanoemulsions. Methods: Three nanoemulsions were prepared using cholesteryl oleate, cholesteryl stearate, or cholesteryl linoleate as main core constituents. Particle size, stability, pH, peroxidation of the nanoemulsions, and cell survival and uptake by different cell lines were evaluated. Results: It was shown that cholesteryl stearate nanoemulsions had the greatest particle size and all three nanoemulsions were stable during the 237-day observation period. The pH of the three nanoemulsion preparations tended to decrease over time, but the decrease in pH of cholesteryl stearate was smaller than that of cholesteryl oleate and cholesteryl linoleate. Lipoperoxidation was greater in cholesteryl linoleate than in cholesteryl oleate and cholesteryl stearate. After four hours' incubation of human umbilical vein endothelial cells (HUVEC) with nanoemulsions, peroxidation was minimal in the presence of cholesteryl oleate and more pronounced with cholesteryl linoleate and cholesteryl stearate. In contrast, macrophage incubates showed the highest peroxidation rates with cholesteryl oleate. Cholesteryl linoleate induced the highest cell peroxidation rates, except in macrophages. Uptake of cholesteryl oleate nanoemulsion by HUVEC and fibroblasts was greater than that of cholesteryl linoleate and cholesteryl stearate. Uptake of the three nanoemulsions by monocytes was equal. Uptake of cholesteryl oleate and cholesteryl linoleate by macrophages was negligible, but macrophage uptake of cholesteryl stearate was higher. In H292 tumor cells, cholesteryl oleate showed the highest uptakes. HUVEC showed higher survival rates when incubated with cholesteryl stearate and smaller survival with cholesteryl linoleate. H292 survival was greater with cholesteryl stearate. Conclusion: Although all three nanoemulsion types were stable for a long period, considerable differences were observed in size, oxidation status, and cell survival and nanoemulsion uptake in all tested cell lines. Those differences may be helpful in protocol planning and interpretation of data from experiments with lipid nanoemulsions.

Ionic and Histological Studies of Salivary Glands in Rats with Diabetes and Their Glycemic State After Laser Irradiation

Objectives: To evaluate the effect of laser irradiation (LI) on the glycemic state and the histological and ionic parameters of the parotid and submandibular glands in rats with diabetes. Methods: One hundred twenty female rats were divided into eight groups. Diabetes was induced by administration of streptozotocin and confirmed later according to results of glycemia testing. Twenty-nine days after the induction, the parotid and submandibular glands of the rats were irradiated with 5, 10, and 20 J/cm(2) using a laser diode (660nm/100mW) (without diabetes: C5, C10, and C20; with diabetes: D5, D10, and D20, respectively). On the following day, the rats were euthanized, and blood glucose determined. Histological and ionic analyses were performed. Results: Rats with diabetes without irradiation (D0) showed lipid droples accumulation in the parotid gland, but accumulation decreased after 5, 10, and 20 J/cm(2) of laser irradiation. A decrease in fasting glycemia level from 358.97 +/- 56.70 to 278.33 +/- 87.98mg/dL for D5 and from 409.50 +/- 124.41 to 231.80 +/- 120.18 mg/dL for D20 (p < 0.05) was also observed. Conclusion: LI should be explored as an auxiliary therapy for control of complications of diabetes because it can alter the carbohydrate and lipid metabolism of rats with diabetes.

Nutrient intakes related to osteoporotic fractures in men and women - The Brazilian Osteoporosis Study (BRAZOS)

Background: Adequate nutrition plays an important role in bone mass accrual and maintenance and has been demonstrated as a significant tool for the prevention of fractures in individuals with osteoporosis. Objective: The aim of the present study was to evaluate bone health-related nutrients intake and its association with osteoporotic fractures in a representative sample of 2344 individuals aged 40 years or older in Brazil. Methods: In a transversal population-based study, a total of 2420 individuals over 40 years old were evaluated from March to April 2006. Participants were men and women from all socioeconomic classes and education levels living around the Brazilian territory Individuals responded a questionnaire including self reported fractures as well a 24-hour food recall. Nutrient intakes were evaluated by Nutrition Data System for Research software (NDSR, University of Minnesota, 2007). Low trauma fracture was defined as that resulting of a fall from standing height or less. Nutrient intakes adequacies were performed by using the DRI's proposed values. Statistical analysis comprises Oneway ANCOVA adjusted by age and use of nutritional supplements and multiple logistic regression. SAS software was used for statistical analysis. Results: Fractures was reported by 13% of men and 15% of women. Women with fractures presented significantly higher calcium, phosphorus and magnesium intakes. However, in all regions and socio-economical levels mean intakes of bone related nutrients were below the recommended levels. It was demonstrated that for every 100 mg/phosphorus increase the risk of fractures by 9% (OR 1.09; IC95% 1.05-1.13, p < 0.001). Conclusion: The results demonstrated inadequacies in bone related nutrients in our population as well that an increase in phosphorus intake is related to bone fractures.

VLT-FLAMES analysis of 8 giants in the bulge metal-poor globular cluster NGC 6522: oldest cluster in the Galaxy? Analysis of 8 giants in NGC 6522

Context. NGC 6522 has been the first metal-poor globular cluster identified in the bulge by Baade. Despite its importance, very few high-resolution abundance analyses of stars in this cluster are available. The bulge metal-poor clusters may be important tracers of the early chemical enrichment of the Galaxy. Aims. The main purpose of this study is to determine metallicity and elemental ratios in individual stars of NGC 6522. Methods. High-resolution spectra of 8 giants of the bulge's globular cluster NGC 6522 were obtained at the 8m VLT UT2-Kueyen telescope with the FLAMES+GIRAFFE spectrograph. Multiband V, I, J, K(s) photometry was used to derive effective temperatures as reference values. Spectroscopic parameters were derived from Fe I and Fe II lines, and adopted for the derivation of abundance ratios. Results. The present analysis provides a metallicity [Fe/H] = -1.0 +/- 0.2. The alpha-elements oxygen, magnesium and silicon show [O/Fe] = +0.4 +/- 0.3, [Mg/Fe] = [Si/Fe] = +0.25 +/- 0.15, whereas calcium and titanium show shallower ratios of [Ca/Fe] = [Ti/Fe] = +0.15 +/- 0.15. The neutron-capture r-process element europium appears to be overabundant by [Eu/Fe] = +0.4 +/- 0.4. The neutron-capture s-elements lanthanum and barium are enhanced by [La/Fe] = +0.35 +/- 0.2 and [Ba/Fe] = +0.5 +/- 0.5. The large internal errors, indicating the large star-to-star variation in the barium and europium abundances, are also discussed. Conclusions. The moderate metallicity combined to a blue horizontal branch (BHB), are characteristics similar to those of HP 1 and NGC 6558, pointing to a population of very old globular clusters in the Galactic bulge. Also, the abundance ratios in NGC 6522 resemble those in HP 1 and NGC 6558. The ultimate conclusion is that the bulge is old, and went through an early prompt chemical enrichment.

Spin-wave fluctuations in ferrimagnetic Mg(x)Fe(3-x)O(4) nanoparticles

We have performed a systematic study of the magnetic properties of a series of ferrimagnetic nanoparticles of Mg(x)Fe(3-x)O(4) (0.8 <= x <= 1.5) prepared by the combustion reaction method. The magnetization data can be well fitted by Bloch's law with T(3/2). Bloch's constant B determined from the fitting procedure was found to increase with Mg content x from similar to 3.09 X 10(-5) K(-3/2) for x = 0.8 to 6.27 X 10(-5) K(-3/2) for x=1.5. The exchange integral J(AB) and the spin-wave stiffness constant D of Mg(x)Fe(3-x)O(4) nanoparticles were also determined as similar to 0.842 and 0.574 meV and 296 and 202 meV angstrom(2) for specimens with x=0.8 and 1.5, respectively. These results are discussed in terms of cation redistribution among A and B sites on these nanostructured spinel ferrites. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3359709]

Crystallization and preliminary X-ray diffraction analysis of recombinant chlorocatechol 1,2-dioxygenase from Pseudomonas putida

Chlorocatechol 1,2-dioxygenase from the Gram-negative bacterium Pseudomonas putida (Pp 1,2-CCD) is considered to be an important biotechnological tool owing to its ability to process a broad spectrum of organic pollutants. In the current work, the crystallization, crystallographic characterization and phasing of the recombinant Pp 1,2-CCD enzyme are described. Reddish-brown crystals were obtained in the presence of polyethylene glycol and magnesium acetate by utilizing the vapour-diffusion technique in sitting drops. Crystal dehydration was the key step in obtaining data sets, which were collected on the D03B-MX2 beamline at the CNPEM/MCT - LNLS using a MAR CCD detector. Pp 1,2-CCD crystals belonged to space group P6(1)22 and the crystallographic structure of Pp 1,2-CCD has been solved by the MR-SAD technique using Fe atoms as scattering centres and the coordinates of 3-chlorocatechol 1,2-dioxygenase from Rhodococcus opacus (PDB entry 2boy) as the search model. The initial model, which contains three molecules in the asymmetric unit, has been refined to 3.4 A resolution.