Bacterial functional redundancy along a soil reclamation gradient

A strategy to measure bacterial functional redundancy was developed and tested with soils collected along a soil reclamation gradient by determining the richness and diversity of bacterial groups capable of in situ growth on selected carbon substrates. Soil cores were collected from four sites along a transect from the Jamari tin mine site in the Jamari National Forest, Rondonia, RO, Brazil: denuded mine spoil, soil from below the canopy of invading pioneer trees, revegetated soil under new growth on the forest edge, and the forest floor of an adjacent preserved forest. Bacterial population responses were analyzed by amending these soil samples with individual carbon substrates in the presence of bromodeoxyuridine (BrdU), BrdU-labeled DNA was then subjected to a 16S-23S rRNA intergenic analysis to depict the actively growing bacteria from each site, the number and diversity of bacterial groups responding to four carbon substrates (L-serine, L-threonine, sodium citrate, and or-lactose hydrate) increased along the reclamation-vegetation gradient such that the preserved forest soil samples contained the highest functional redundancy for each substrate. These data suggest that bacterial functional redundancy increases in relation to the regrowth of plant communities and may therefore represent an important aspect of the restoration of soil biological functionality to reclaimed mine spoils. They also suggest that bacterial functional redundancy may be a useful indicator of soil quality and ecosystem functioning.

Entendendo as propriedades do arenito Botucatu e sua utilização como meio poroso para estudos envolvendo o deslocamento de fluidos poliméricos

The development of products whose purpose is to promote blockages in high permeability zones as well as to control the hydrate or scale formation also needs some tests in porous media before using the product in the field, where attempts and unavoidable operational errors costs would able to derail any projects. The aim of this study was to analyze and compare the Botucatu and Berea sandstones properties, involving problems related to loss permeability. It was observed that even cores of Berea, without expansible clays in their composition had their permeability reduced, as soon as the salinity of brine reached a lower limit. As expected, the same happened with the Botucatu sandstone samples, however, in this case, the sensitivity to low salinity was more pronounced. In a second phase, the research was focused on the Botucatu Sandstone behavior front of dilute polymer solutions injection, checking the main relationships between the Rock / Fluid interactions, considering the Mobility Reduction, Resistance and Residual Resistance Factors, as well as adsorption/desorption processes of these polymers, and the polymer molecules average size and porous sandstone average size ratio. The results for both phases showed a real feasibility of using the Botucatu sandstone in laboratory tests whose objective is the displacement of fluids through porous media

Implantes de polietileno gel e poroso em cavidade anoftálmica de coelhos

OBJETIVO: Comparar implantes de polietileno poroso no estado sólido e gel em cavidades enucleadas. MÉTODOS: Trinta e seis coelhos albinos foram submetidos à enucleação do olho direito, recebendo esferas de polietileno poroso (18 animais) ou gel (18 animais), de 12 mm de diâmetro. Os animais foram avaliados semanalmente por exame clínico e mensalmente por ultra-sonografia modo B, realizada 30, 60 e 90 dias após a cirurgia, tendo sido os animais sacrificados aos 90 dias. Após o sacrifício, o conteúdo orbitário foi removido e examinado histologicamente. RESULTADOS: Cinco animais (27,2%) que receberam os implantes de polietileno poroso tiveram extrusão do implante. Houve extrusão em 94,4% dos animais que receberam a esfera de polietileno gel, tendo-se observado que o diâmetro das esferas gel extruídas encontrava-se aumentado em relação ao diâmetro da esfera implantada. A ultra-sonografia mostrou que o implante de polietileno poroso se vascularizou e que o gel não, o que foi confirmado pelo exame histológico. CONCLUSÃO: Esferas de polietileno no estado gel sofrem hidratação e aumentam de volume, sendo necessário conhecer o seu tamanho final antes da implantação. A ultra-sonografia permite conhecer a vascularização do implante, podendo ser usada na avaliação da integração esfera-hospedeiro.

Free radical scavenging activity of Pterogyne nitens Tul. (Fabaceae)

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

Microwave-assisted hydrothermal synthesis of structurally and morphologically controlled sodium niobates by using niobic acid as a precursor

There are many advantages to using a microwave as a source of heat in hydrothermal reactions. Because it is a quick and homogeneous way to crystallize ceramic powders, it was used in this work for the production of antiferroelectric sodium mobate (NaNbO3) in a cubic-like form and its intermediary phase, disodium diniobate hydrate (Na2Nb2O6 center dot H2O), with a fiber morphology. The syntheses were carried out by treating niobic acid (Nb2O5 center dot nH(2)O) with NaOH. By changing the reaction time and the concentration of the reactants, particles with different structures and different morphologies could be obtained. The structural evolution of the products of this reaction was elucidated on the basis of the arrangement of the NbO6 octahedral units. Conclusive results were obtained with morphological and structural characterizations through XRD, TEM, MEV, and NMR and Raman spectroscopy. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008).

Essential oil of Lithraea molleoides (Vell.): chemical composition and antimicrobial activity

Lithraea molleoides(Vell.) (Anacardiaceae) é uma árvore encontrada no Brasil, Paraguai, Bolívia, Uruguai, Argentina e Chile. É popularmente usada na forma de extrato alcoólico, decocção e infusão para o tratamento de tosse, bronquite, artrite, doenças do sistema digestivo, como diurético, tranqüilizante, hemostático e tônico. O objetivo do presente estudo foi a extração do óleo essencial dos frutos maduros, folhas e outras partes aéreas da planta e o rendimento do mesmo; a identificação e quantificação dos principais componentes e a determinação da atividade antimicrobiana. O rendimento do óleo essencial dos frutos maduros foi de 1%, entretanto, não foi encontrado óleo essencial nas partes aéreas da planta. A análise do óleo essencial por cromatografia gasosa com espectrometria de massa, mostrou a presença de limoneno (89,89%), alfa-pineno (3,48%), beta-pineno (2,63%), alfa-terpineol (1.27%), mirceno (0,64%), sabineno (0,54%), 4-terpineol (0,28%), canfeno (0,22%) e delta-3-careno (0,13%). O óleo essencial foi ativo contra algumas bactérias Gram positivas e leveduras testadas e não apresentou atividade contra bactérias Gram negativas.

Apoptosis in the epithelial cells of the rests of Malassez of the periodontium of rat molars

Background and Objectives: Epithelial rests of Malassez are clusters of cells derived from Hertwig's root sheath that remain in the periodontal ligament throughout life. Although it is known that the cells of Malassez proliferate, there are no studies showing that they undergo programmed cell death, i.e. apoptosis. In most tissues, proliferation is balanced by apoptosis. Thus we examined regions of the periodontium of young and adult rat molars in the hope of detecting apoptosis.Methods: Wistar rats aged 29, 45 and 120 days were killed with chloral hydrate (600 mg/kg). Fragments containing maxillary molars were removed and fixed in formaldehyde, decalcified, and embedded in paraffin and glycol methacrylate. Sections were stained with hematoxylin/eosin and the Terminal deoxynucleotidyl transferase-mediated dUTP Nick End Labeling (TUNEL) method for detection of apoptosis. Specimens were also fixed in glutaraldehyde-formaldehyde, decalcified and processed for transmission electron microscopy.Results: Epithelial rests of Malassez containing round/ovoid basophilic dense bodies and TUNEL-positive structures were found in all specimens examined. Ultrastructural examination revealed that some cells of Malassez contained masses of condensed peripheral chromatin and a shrunken cytoplasm exhibiting intact organelles - images typical of apoptosis. Moreover, round/ovoid electron-opaque structures appeared to be in the process of being engulfed by neighboring epithelial cells of Malassez.Conclusions: Our results demonstrate that epithelial cells of Malassez's rests undergo apoptosis in the developing and adult periodontium. Apoptosis may, together with proliferation, be part of the mechanism of turnover/remodelling of the cells of Malassez.

Determination of the vinylsulphone azo dye, remazol brilliant orange 3R, by cathodic stripping voltammetry

Remazol brilliant orange 3R shows only a voltammetric peak for the reduction of the azo group. No peak was observed for the reduction of the sulfatoethylsulfone or vinylsulfone reactive groups. The reduction of a pre-protonated ate group involving a two-electron process, gives a hydrate derivative in acidic solution. In alkaline solution the reduction process occurs at more negative potential with the formation of an unstable hydrate compound which decomposes via HN-NH bond cleavage and loss of a sulfate group. Optimum conditions are given for the cathodic stripping voltammetric determination of dir: dye in aqueous solution. The optimum accumulation potential and time were 0 V and up to 60 s, respectively. Linear calibration graphs were obtained from 30 to 300 ng ml(-1) in pH 4 and 6.2 to 62 ng ml(-1) in pH 10. The limit of determination obtained was 1.5 ng ml(-1) (pH 10). The coefficient of variation was 2.6% (n = 7) at 62 ng ml(-1) of the reactive dye. (C) 1999 Elsevier B.V. B.V. All rights reserved.

Análise da dieta e condição de saúde bucal em pacientes gestantes

Objectve: To perform a critical analysis of the diet record model adopted, to evaluate the cariogenicity of the maternal diet, and the incidence of dental caries in pregnant women treated at a prevent on clinic in an undergraduate dental course. Method: A cross-sectional study was performed with consultations to the database of the clinic and review of patients' charts and diet records. The sample was calculated and 205 patents were randomly selected. Bivariate statistical analysis was done at a significance level of 5% (α=0.05), using the statistical soft wares Epi Info versão 3.2, GraphPad Instat 3.6 and BioEstat. Results: The analysis of the diet records showed that 68.8% of the pregnant women presented a cariogenic diet, with high frequency of ingest on of fermentable carbon hydrates, mainly sucrose, with liquid consistency, and preferably consumed between the main meals. There was higher trend of the pregnant women mentioning a low frequency of carbon hydrate ingestion during the interview, while registering a diet rich of these components in their diet records (p<0.0001). The mean DMFT of the patients was 13.9 ± 5.4. There was no statistically significant association between diet and oral health variables (p>0.05). Conclusion: The diet record was proven an effective and valid method, if correctly employed. The prevalence of dental caries in the group of pregnant women was high and, although more than half of the sample presented a cariogenic diet, a significant association between diet and co-factors was not found.

Free radical scavenging activity of Kielmeyera variabilis (Clusiaceae)

As part of our ongoing research on antioxidant agents from Brazilian flora, we screened the free radical scavenging activity of two extracts and eight fractions of Kielmeyera variabilis (Clusiaceae) using DPPH (2,2-diphenyl-1- picrylhydrazyl-hydrate) and ABTS+ [2,2'-azinobis(3- ethylenebenzothiazoline-6-sulfonic acid)] colorimetric assays. The ethyl acetate and n-butanol fractions of the leaves of K. variabilis displayed the strongest activity (IC50 of 3.5 ± 0.3 and 4.4 ± 0.2 μg mL -1 for DPPH and 6.6 ± 0.4 and 3.1 ± 0.1 μg mL -1 for ABTS+, respectively). Chromatographic fractionation of the most potent fractions led to identification of three flavonols with previously described antioxidant activity, quercitrin (1), quercetin-3-O- glucoside (3), and quercetin-3-O-galactoside (4), and of one biflavone, podocarpusflavone A (2). This is the first time that the presence of these flavonoids in Kielmeyera variabilis has been reported. © 2013 by the authors.

Determination of disease biomarkers in Eucalyptus by comprehensive two-dimensional gas chromatography and multivariate data analysis

In this paper is reported the use of the chromatographic profiles of volatiles to determine disease markers in plants - in this case, leaves of Eucalyptus globulus contaminated by the necrotroph fungus Teratosphaeria nubilosa. The volatile fraction was isolated by headspace solid phase microextraction (HS-SPME) and analyzed by comprehensive two-dimensional gas chromatography-fast quadrupole mass spectrometry (GC. ×. GC-qMS). For the correlation between the metabolic profile described by the chromatograms and the presence of the infection, unfolded-partial least squares discriminant analysis (U-PLS-DA) with orthogonal signal correction (OSC) were employed. The proposed method was checked to be independent of factors such as the age of the harvested plants. The manipulation of the mathematical model obtained also resulted in graphic representations similar to real chromatograms, which allowed the tentative identification of more than 40 compounds potentially useful as disease biomarkers for this plant/pathogen pair. The proposed methodology can be considered as highly reliable, since the diagnosis is based on the whole chromatographic profile rather than in the detection of a single analyte. © 2013 Elsevier B.V..

Comportamento mecânico e de flamabilidade de compósito de polipropileno reclicado com fibra de coco e hidróxido de alumínio

A reciclagem de plásticos tem sido uma possibilidade interessante para minimizar o problema de destino dos resíduos plásticos. O polipropileno (PP) está entre os tipos de polímeros de maior consumo, portanto a reutilização deste material tem possibilitado o desenvolvimento de estudos de grande relevância científica e social. Este polímero apresenta excelente relação custo/benefício, além de ser facilmente conformável e exibir propriedades mecânicas que o torna útil em várias aplicações. Entretanto, esse material ao ser queimado gera produtos que agem como combustíveis de modo que, para alguns usos, boa resistência à chama é necessária. Isso pode ser obtido pela adição de retardante de chama, que tem o propósito de aumentar a resistência desse material à ignição e, ao mesmo tempo, reduzir a velocidade de propagação da chama. O hidróxido de alumínio, ou simplesmente hidrato de alumina, é o agente retardante de chama mais utilizado no mercado, pois, age também como supressor de fumaça e não libera gases tóxicos durante a queima. No entanto, para tais propriedades, altas concentrações de alumina hidratada são necessárias. Isto causa deterioração nas propriedades físicas dos materiais, por não ter caráter reforçante. As fibras naturais possuem boa capacidade de reforço quando combinadas adequadamente com polímeros. Apresentando também vantagens como baixo custo, baixa densidade, biodegradabilidade e na combustão não emana gases tóxicos. Neste trabalho, misturas contendo alumina hidratada e fibras de coco foram incorporadas ao polipropileno com o objetivo de se encontrar um balanço adequado de propriedades para utilização deste compósito com características de resistência à chama e desempenho mecânico. Os compósitos foram moldados por compressão a quente e caracterizados por IV, DRX, MEV, testes mecânicos e de inflamabilidade. Foi observado aumento no módulo de elasticidade dos compósitos em geral, bem como aumento na resistência a tenacidade do compósito PP/fibra de coco em relação ao PP puro. Os resultados indicaram a eficiência da alumina hidratada como antichama, em todos os compósitos, exceto PP/F, classificando os materiais como V-0 segundo a norma internacional UL 94V.

Fitoquímica e quimiossistemática de Euxylophora paraensis (Rutaceae)

ABSTRACT: Phytochemical studies of the leaves and stem have led to the identification of the known coumarins isooxypeucedanin, oxypeucedanin hydrate, xanthotoxin, isopimpinellin, 8-methoxymarmesin and marmesin, flavonoids quercetin-3-O-α-L-rhamnopyranoside, myricetin-3-O-α-L-rhamnopyranoside and hesperidin, alkaloids skimmianine and N-methylflindersine and limonoid limonin. The compounds isolated and the chemical profile of Euxylophora obtained from the literature clearly indicate its phytochemical affinities with other Rutoideae species.

Effect of colloidal silica on the mechanical properties of fiber-cement reinforced with cellulosic fibers

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

Atenolol characterization in solid formulations available in Brazilian market

Atenolol is the most used drug in Brazil to hypertension treatment. Two crystal structures are known for this molecule: a racemic form (R,S)-atenolol and a pure form S-atenolol. The racemic form is found in commercial tablets. X-ray powder diffraction (XRD) is an adequate tool to study crystalline structures including drugs. Using the Rietveld Method with XRD data it is possible to quantify the crystalline structures existing in the raw material. Other methods like Le Bail and Pawley can be used to the profile fit and phases identification. For this work we analyzed three tablets of atenolol, two generics and the reference (materials were purchased from a drugstore at the city of Araraquara). These tablets were analyzed by Rietveld, Le Bail and Pawley methods. All tablets exhibited the racemic mixture API (R,S)-atenolol. Some crystalline excipients could be characterized: magnesium carbonate hydrate, lactose monohydrate and talc. The conclusion is that the three methods can be efficiently used to characterize the three atenolol tablets.