4,495 research outputs found

    Overindebtedness and self-perception of social status – a case study in great Porto region (Portugal)

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    The aim of this paper is to explore the relationship of self-perception of social status (SPS) and propensity towards indebtedness related to consumer goods' acquisitions. It also intends to identify the variables that discriminate the propensity towards overindebtness. We have used a questionnaire specifically designed for this purpose, using several elements from Gathergood (2012) and Adler & Stewart (2007) questionnaires. The survey includes 312 individuals, the majority living in the Greater Porto area. Using logit regression and discriminant analysis, we observed that SPS might plays a significant role in the process of indebtedness and overindebtedness. Only gender did not have an association with indebtedness. Education should also be a distinctive factor between all the three groups of indebtedness.info:eu-repo/semantics/publishedVersio

    Do bioactive carotenoids contribute to the color of edible mushrooms?

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    Carotenoids are biologically active phytochemicals present as micro-components in fruits and vegetables, being responsible for their yellow, orange and red colors. The chromatographic behavior and the UV absorption spectrum provided by HPLC-DAD analysis constitute the clues for their identification. Mushrooms are of increasing importance in modern nutrition and medicine, due to the presence of metabolites with pharmacological potential. In this work, samples of wild and commercial mushroom species (Agaricus bisporus, Amanita caesarea, Amanita rubescens, Boletus edulis, Cantharellus cibarius, Fistulina hepatica, Hydnum rufescens, Hygrophorus agathosmus, Pholiota nameko, Pleurotus ostreatus, Russula cyanoxantha, Suillus bellini, Suillus bovinus, Suillus granulatus, Suillus luteus, Tricholoma equestre and Tricholoma portentosum) were screened by HPLC-DAD for the presence of carotenoids. By applying this methodology to 22 samples, comprising either lyophilized or fresh materials, only β-carotene was found and just in C. cibarius species. The occurrence of this pigment in other three of the analyzed species previously described raises some questions about the methodology used.info:eu-repo/semantics/publishedVersio

    Toxicity and structure-activity relationship (SAR) of α, β-dehydroamino acids against human cancer cell lines

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    A library of N-protected dehydroamino acids, namely dehydroalanine, dehydroaminobutyric acid and dehydrophenylalanine derivatives, was screened in three human cancer cell lines [(lung (A549), gastric (AGS) and neuroblastoma (SH-SY5Y)] in order to characterize their toxicological profile and identify new molecules with potential anticancer activity. Results showed N-protected dehydrophenylalanine and dehydroaminobutyric acid derivatives have no or low toxicity for all tested cell lines. The N-protected dehydroalanines exhibit significant toxic effects and the AGS and SH-SY5Y cells were significantly more vulnerable than A549 cells. Four α,β- dehydroalanine derivatives, with IC50 < 62.5 μM, were selected to investigate the pathways by which these compounds promote cell death. All compounds, at their IC50 concentrations, were able to induce apoptosis in both AGS and SH-SY5Y cell lines. In both cell lines, loss of mitochondrial membrane potential (ΔΨm) was found and caspase activity was increased, namely endoplasmic reticulum-resident caspase-4 in AGS cells and caspase-3/7 in SH-SY5Y cells. When evaluated in a non-cancer cell line, the molecules displayed no to low toxicity, thus suggesting some degree of selectivity for cancer cells. The results indicate that α,β-dehydroalanine derivatives can be considered a future resource of compounds able to work as anticancer drugs.This work received financial support from National Funds (FCT/MEC) through Project UID/QUI/50006/2013, co-financed by European Union (FEDER under the Partnership Agreement PT2020); and from Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF) (project NORTE-01-0145-FEDER 000024).info:eu-repo/semantics/publishedVersio

    Synthesis and preliminary biological evaluation of new phenolic and catecholic dehydroamino acid derivatives

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    A library of N-phenolic and N-catecholic dehydroamino acid derivatives was prepared using an innovative synthetic strategy that involves mild reaction conditions and simple work-up procedures. The method comprises coupling of phenolic or catecholic acids with β-hydroxyamino acids followed by tert-butyloxycarbonylation of all hydroxyl groups using tert-butyldicarbonate and 4-dimethylaminopyridine as catalyst. Treatment of these amino acids with N,N,N’,N’-tetramethylguanidine affords the corresponding O-tert-butyloxycarbonyldehydro-amino acid derivative. Deprotection of the aromatic hydroxyl groups is carried out with trifluoroacetic acid. This synthetic strategy can be applied in a one-pot procedure and yields compounds that can be easily inserted into peptides or other biomolecules after cleavage of the C-protecting group. Preliminary studies of cell viability show that these new compounds display very low or no toxicity. These dehydroamino acids with a phenolic or catecholic moiety can have intrinsic biological activity or used to prepare new hydrogels that mimic mussel adhesive proteins.This work received financial support from the Foundation for Science and Technology (FCT, Portugal), through projects UID/QUI/00686/2013, UID/QUI/00686/2016 (CQUM) and UID/QUI/50006/2013-POCI-01-0145-FEDER-007265, co-financed by European Union (FEDER under the Partnership Agreement PT2020), and from Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF) (project NORTE-010145-FEDER-24).info:eu-repo/semantics/publishedVersio

    Xanthone biosynthesis and accumulation in calli and suspended cells of Hypericum androsaemum

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    Calli and suspended cells of Hypericum androsaemum accumulated high levels of 1,3,5,6 and 1,3,6,7 oxygenated xanthones. The major compounds include simple oxygenated xanthones or derivatives with prenyl, pyran or methoxyl groups, four of them being new natural compounds. A hypothetical biosynthetic scheme is proposed based on the isolated compounds and statistical analysis. Xanthone accumulation was influenced greatly by medium factors, namely hormone supplementation. Calli grown with 4.5 mM a-naphtaleneacetic acid (NAA) 2.3 mM kinetin (KIN) had the highest specific xanthone production (1.3% biomass dry weight (DW)), whereas suspended cells grown in similar medium accumulated a lower amount (0.87% DW). Calli displayed a negative linear relationship between total xanthone accumulation and NAA concentration, in the range of 4.5–22.5 mM. However, in this range the xanthone 1,3,6,7:1,3,5,6 ratio and the biomass production showed a positive linear relationship with NAA concentration. Substitution of 4.5 mM of NAA by the same molar amount of 2,4-dichlorophenoxyacetic acid (2,4-D), in the presence of 2.3 mM of KIN, caused a decrease in xanthone accumulation in calli. The use of N6-benzyladenine (BA) instead of KIN reduced xanthone production, independently of the auxin used. This effect was attenuated when both hormones were present.Fundação para a Ciência e a Tecnologia (FCT

    The drinking of a Salvia officinalis infusion improves liver antioxidant status in mice and rats

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    In this study we evaluate the biosafety and bioactivity (antioxidant potential) of a traditional water infusion (tea) of common sage (Salvia officinalis L.) in vivo in mice and rats by quantification of plasma transaminase activities and liver GST and GR enzyme activities. The replacement of water by sage tea for 14 days in the diet of rodents did not affect the body weight and food consumption and did not induce liver toxicity. On the other hand, a significant increase of liver GST activity was observed in rats (24%) and mice (10%) of sage drinking groups. The antioxidant potential of sage tea drinking was also studied in vitro in a model using rat hepatocytes in primary culture. The replacement of drinking water with sage tea in the rats used as hepatocyte donors resulted in an improvement of the antioxidant status of rat hepatocytes in primary culture, namely a significant increase in GSH content and GST activity after 4 hours of culture. When these hepatocyte cultures were exposed to 0.75 or 1 mM of tert-butyl hydroperoxide for 1 hour, some protection against lipid peroxidation and GSH depletion was conferred by sage tea drinking. However, the cell death induced by t-BHP as shown by LDH leakage was not different from that observed in cultures from control animals. This study indicates that the compounds present in this sage preparation contain interesting bioactivities which improve the liver antioxidant potential.Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BD/6942/2001, Programa Operacional “Ciência, Tecnologia, Inovação” (POCTI) - POCTI/AGR/43482/2001

    Solvent extraction of sodium chloride from codfish (Gadus morhua) salting processing wastewater

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    Codfish is worldwide mostly consumed salt-cured due to the highly appreciated sensory characteristics promoted by salt. During the salting process huge amounts of salted wastewater are generated – approximately 22% w/w of the codfish – carrying ca. 250 g/L of sodium chloride and ca. 10 g/L of organic compounds, namely proteins and free amino acids. In this study, the salt load of wastewater generated during the salting process of codfish (Gadus morhua) was successfully reduced by ethanol extraction. The effects of time, sample:ethanol ratio, pH and temperature on salt extraction by ethanol addition were assessed by a onevariable-at-a-time approach and then by performing a 32 fractional factorial design. The effects of pH were also assessed in absence of ethanol. The maximum amount of salt precipitated in the wastewater was ca. 33%, at a wastewater-ethanol ratio 1:1 (v/v), at a temperature of 0 °C and after 30 min. Proteins and free amino acids present in the wastewater significantly limited salt precipitation; in a blank solution (salt in water at ca. 250 g/L) a higher amount of salt, ca. 37%, was precipitated in the same conditions. Ethanol and temperature showed a linear effect on salt precipitation for both wastewater and blank solution however ethanol was the driving factor. Changes in pH did not result in salt precipitation either in absence or presence of ethanol. During salt extraction, no precipitation of free amino acids occurred in the wastewater while ca. 1.4% of protein fell into the precipitated phase along with the salt

    Produção de fitomassa leguminosas isoladas e consorciadas com milheto e teor relativo de clorofila em feijoeiro orgânico em plantio direto.

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    O objetivo do presente trabalho foi de avaliar a produção de fitomassa de leguminosas isoladas e consorciadas com milheto e seu efeito no teor de clorofila do feijoeiro comum orgânico em sistemas de plantio convencional e direto.CONAFE

    IgY-Technology Applied to Studies of Toxoplasma gondii Infection

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    In this chapter, we describe relevant aspects of immunoglobulin Y (IgY) technology for Toxoplasma gondii applications, including comparison of avian IgY antibody with mammalian IgG antibody, egg yolk IgY production and isolation procedures, important applications for IgY antibody, and state of the art and perspectives for IgY‐technology in T. gondii studies. T. gondii is a worldwide public health problem. IgY‐technology provides an alternative antibody (IgY) to mammalian Immunoglobulin G (IgG) antibody. IgY‐technology involves the chicken immunization, yolk IgY isolation, antibody characterization, and purified IgY application to several kinds of methods. Immunized chicken transfers a specific IgY from blood to egg yolk. Phylogenetic distance between chickens and mammals influences the generation of antibody repertoires recognizing an antigen profile. IgY is not bound to rheumatoid factor or mammalian complement protein and thus avoids the false‐positive results. Yolk IgY isolation is carried out by simple procedures that are accessible for any laboratory and, also, for IgY isolation at large‐scale production. IgY‐technology provides antibodies for proteomic studies, diagnostic assays, and immunotherapy. Although IgY‐technology is promising, there is a reduced number of investigations with IgY and T. gondii. Future perspectives involve the use of IgY‐technology for the screening of new T. gondii antigens for diagnostics, therapy, or vaccine, development of innovative techniques for toxoplasmosis diagnostics and may be an immunotherapy for toxoplasmosis
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