1,457 research outputs found

    Profile, antioxidant potential, and applicability of phenolic compounds extracted from Spirulina platensis

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    This work aimed at an investigation of the profile of free phenolic compounds (PC) of Spirulina platensis and assesses their antioxidant potential, applying them as a natural conservative in minimally processed apples. The phenolic extract showed 396 &µg g-1 gallic acid, 347 µg g-1 of caffeic acid, 54 µg g-1 salicylic acid and 3.5 µg g-1 trans-1-cinmamic a total of 608 µg PC g-1 of S. platensis. With the use of PC, it was possible to inhibit the radical DPPH over 180 min with IC50 of PC 202 µg mL-1. The inhibition of polyphenol oxidase and peroxidase of PC were 19.9 and 9.7%. In addition, verifying the constants Km and Vmax, it was concluded that  inhibition of the peroxidase and polyphenol occurs in an uncompetitive manner. Application of crude extract of PC under minimally processed apples showed  inhibition of browning by 40%. The general acceptance of apples was not affected by the addition of PC.Key words: Apple, enzymatic browning, peroxidase, phenols, polyphenol oxidase

    Resonance Raman scattering studies in Br-2-adsorbed double-wall carbon nanotubes

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    ArticlePhysical Review B. 73(23):235413 (2006)journal articl

    EXPANDED BED ADSORPTION OF BROMELAIN (EC 3.4.22.33) FROM Ananas comosus CRUDE EXTRACT

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    Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)This work focuses on the adsorption of Bromelain in expanded bed conditions, such as the adsorption kinetics parameters. The adsorption kinetics parameters showed that after 40 minutes equilibrium was achieved and maximum adsorption capacity was 6.11 U per resin mL. However, the maximum adsorption capacity was only determined by measuring the adsorption isotherm. Only by the Langmuir model the maximum adsorption capacity, Qm, and dissociation constant, kd, values could be estimated as 9.18 U/mL and 0.591, respectively, at 25 degrees C and 0.1 mol/L phosphate buffer pH 7.5. A column made of glass with an inner diameter of 1 cm was used for the expanded bed adsorption (EBA). The residence time was reduced 10 fold by increasing the expansion degree 2.5 times; nonetheless, the plate number (N) value was reduced only 2 fold. After adsorption, the bromelain was eluted in packed bed mode, with a downward flow. The purification factor was about 13 fold and the total protein was reduced 4 fold. EBA showed to be feasible for purification of bromelain.261149157Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    Partitioning optimization of proteins from Zea mays malt in ATPS PEG 6000/CaCl2

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    This work aimed to establish the relationship between the compositions and pH of ATPS PEG 6000/CaCl2 and the proteins partition from maize malt and also to simplify the process optimization in ATPS for a statistical model, established by response surface methodology (RSM). Results showed that these were no influence of pH on the phase diagrams and on the composition of tie line length of PEG 6000/CaCl2 ATPS. SRM analyses showed that elevated pH and larger tie line length were the best conditions for recovering of maize malt proteins. The maximum partition coefficient by PEG 6000/CaCl2 ATPS was about 4.2 and was achieved in ATPS in a single purification step. The theoretical maximum partition coefficient was between 4.1-4.3. The process was very suitable for continuous aqueous two phase purification due to the stability of proteins (e.g. alpha and beta-amylases) and could increase their content into middle.50355756

    Geographic Coincidence of Increased Malaria Transmission Hazard and Vulnerability Occurring at the Periphery of two Tanzanian Villages.

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    The goal of malaria elimination necessitates an improved understanding of any fine-scale geographic variations in transmission risk so that complementary vector control tools can be integrated into current vector control programmes as supplementary measures that are spatially targeted to maximize impact upon residual transmission. This study examines the distribution of host-seeking malaria vectors at households within two villages in rural Tanzania. Host-seeking mosquitoes were sampled from 72 randomly selected households in two villages on a monthly basis throughout 2008 using CDC light-traps placed beside occupied nets. Spatial autocorrelation in the dataset was examined using the Moran's I statistic and the location of any clusters was identified using the Getis-Ord Gi* statistic. Statistical associations between the household characteristics and clusters of mosquitoes were assessed using a generalized linear model for each species. For both Anopheles gambiae sensu lato and Anopheles funestus, the density of host-seeking females was spatially autocorrelated, or clustered. For both species, houses with low densities were clustered in the semi-urban village centre while houses with high densities were clustered in the periphery of the villages. Clusters of houses with low or high densities of An. gambiae s.l. were influenced by the number of residents in nearby houses. The occurrence of high-density clusters of An. gambiae s.l. was associated with lower elevations while An. funestus was also associated with higher elevations. Distance from the village centre was also positively correlated with the number of household occupants and having houses constructed with open eaves. The results of the current study highlight that complementary vector control tools could be most effectively targeted to the periphery of villages where the households potentially have a higher hazard (mosquito densities) and vulnerability (open eaves and larger households) to malaria infection

    Maids, machines and morality in Brazilian homes

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    This paper engages with debates about the increasing use of paid domestic labour in Europe and the USA contributing with a reflection about the case of Brazil. Relations of gender, class and race are considered in the deployment of maids for housework, the patterns of consumption of household technologies and the moral reasoning of daily living with hierarchical divisions within the home. The paper considers some parallels between the Brazilian context and that of more developed countries and also the specificity of Brazil. Based on participant observation, secondary data and an ethnographic study, rich empirical data are weaved through to discuss material and moral dimensions of domestic labour and care. How does the availability of cheap domestic labour configure relations of inequality? How are social differences in the home lived with and justified? The exploration of the Brazilian case illuminates some of the problems, contradictions and possible consequences of wealthier households benefitting from the displacement of poor women that is currently happening through international migration. The paper argues that in Brazil the deflecting of tensions in gender divisions of labour in households onto a subordinate person has affected relations of equality between women and men and also the patterns of technological innovation to facilitate housework. These are outcomes to be guarded against in Europe and the United States in face of the current trends in 'global woman' relations

    On domain walls in a Ginzburg-Landau non-linear S^2-sigma model

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    The domain wall solutions of a Ginzburg-Landau non-linear S2S^2-sigma hybrid model are unveiled. There are three types of basic topological walls and two types of degenerate families of composite - one topological, the other non-topological- walls. The domain wall solutions are identified as the finite action trajectories (in infinite time) of a related mechanical system that is Hamilton-Jacobi separable in sphero-conical coordinates. The physical and mathematical features of these domain walls are thoroughly discussed.Comment: 26 pages, 18 figure

    The Chinese version of the Obsessive-Compulsive Inventory-Revised scale: Replication and extension to non-clinical and clinical individuals with OCD symptoms

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    <p>Abstract</p> <p>Background</p> <p>The Obsessive-Compulsive Inventory-Revised (OCI-R) was designed to evaluate the severity of obsessive-compulsive symptoms in both clinical and non-clinical samples. The aim of the study was to evaluate the psychometric properties of a Chinese version of this scale.</p> <p>Methods</p> <p>The Chinese version of the OCI-R was administered to both a non-clinical sample (209 undergraduate students) and a clinical sample (56 obsessive-compulsive disorder (OCD) patients). Confirmatory factor analysis was conducted to examine the construct validity of the OCI-R in the non-clinical sample. The internal consistency at baseline and test-retest reliabilities at 4-week interval was examined in both the non-clinical and clinical samples.</p> <p>Results</p> <p>The confirmatory factor analysis of the non-clinical sample confirmed a 6-factor model suggested by the original authors of the instrument (df = 120, RMSEA = 0.068, CFI = 0.88, NNFI = 0.85, GFI = 0.89). The internal consistency and test-retest reliability were at an acceptable range for both the non-clinical and clinical samples. The OCI-R also showed good clinical discrimination for patients with OCD from healthy controls.</p> <p>Conclusions</p> <p>The Chinese version of the OCI-R is a valid and reliable instrument for measuring OCD symptoms in the Chinese context.</p

    Stressor- and Corticotropin releasing Factor-induced Reinstatement and Active Stress-related Behavioral Responses are Augmented Following Long-access Cocaine Self-administration by Rats

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    Rationale Stressful events during periods of drug abstinence likely contribute to relapse in cocaine-dependent individuals. Excessive cocaine use may increase susceptibility to stressor-induced relapse through alterations in brain corticotropin-releasing factor (CRF) responsiveness. Objectives This study examined stressor- and CRF-induced cocaine seeking and other stress-related behaviors in rats with different histories of cocaine self-administration (SA). Materials and methods Rats self-administered cocaine under short-access (ShA; 2 h daily) or long-access (LgA; 6 h daily) conditions for 14 days or were provided access to saline and were tested for reinstatement by a stressor (electric footshock), cocaine or an icv injection of CRF and for behavioral responsiveness on the elevated plus maze, in a novel environment and in the light–dark box after a 14- to 17-day extinction/withdrawal period. Results LgA rats showed escalating patterns of cocaine SA and were more susceptible to reinstatement by cocaine, EFS, or icv CRF than ShA rats. Overall, cocaine SA increased activity in the center field of a novel environment, on the open arms of the elevated plus maze, and in the light compartment of a light–dark box. In most cases, the effects of cocaine SA were dependent on the pattern/amount of cocaine intake with statistically significant differences from saline self-administering controls only observed in LgA rats. Conclusions When examined after several weeks of extinction/ withdrawal, cocaine SA promotes a more active pattern of behavior during times of stress that is associated with a heightened susceptibility to stressor-induced cocaine-seeking behavior and may be the consequence of augmented CRF regulation of addiction-related neurocircuitry
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