635 research outputs found

    Yield of soybean genotypes under infestation of the velvetbean caterpillar and stink bugs

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    Three soybean experiments, one for each maturation group (early, semi-early, and medium), were installed in the field in Assis, State of SĂŁo Paulo, during the 2003/2004 growing season to evaluate damage caused by Anticarsia gemmatalis (Hubn.) and by the soybean stink bug complex, Euschistus heros (F.), Piezodorus guildinii (West.), and Nezara viridula (L.). The experiments were installed again in 2004/2005, with the exception of the early cycle group. Defoliation caused by A. gemmatalis was evaluated by the percentage estimate of leaf area cut in the first year only, due to low caterpillar infestations in 2004/2005. All three stink bug species were present in both growing seasons. In 2003/2004, E. heros was predominant over the other two; in the following year, all three species occurred in similar numbers. The productivity criterion was adopted to evaluate stink bug damage. Based on both growing seasons and mainly considering productivity, a few lines could be selected within each maturation group for new field studies or for hybridizations in breeding programs. Among the early germplasm varieties, lines IAC 98-4540, IAC 98-4576, and IAC 98-3123 can be highlighted as promising; the latter also showed little defoliation by A. gemmatalis; in the semi-early group, IAC 98-4017, IAC 98-2663, and IAC 98-4250 were prominent, with steady productivity in both years; in the medium group, IAC 98-4136, the most productive, as well as IAC 98-4140 and IAC 98-4133, all with little defoliation, can be pointed out as promising.Conselho Nacional de Desenvolvimento CientĂ­fico e TecnolĂłgico (CNPq

    Modification of PET surfaces with Gum Arabic towards its bacterial anti-adhesiveness using an experimental factorial design approach

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    Bacterial adhesion onto hospital material surfaces still represents a big healthcare issue, being preventive measures required to mitigate this problem, such as increasing material surface hydrophilicity. In the present study, gum Arabic, a hydrophilic polysaccharide, was used to modify the surface of polyethylene terephthalate (PET). Initial water contact angle (WCA) and WCA after several washing cycles were studied as response variables by a 24 full factorial design. Several reaction parameters, such as contact time between gum Arabic and PET, gum Arabic concentration, curing temperature and curing time for PET modification were investigated. The most significant parameters were found to be the curing temperature and curing time. The optimized parameters led to a WCA reduction from 70° to 27°. The modified PET samples were characterized using several techniques including AFM, colorimetric, ATR-FTIR and contact angle which further confirmed a successful surface modification. Furthermore, bacterial adhesion assays have clearly shown that the treated PET material was highly effective in preventing the bacterial adhesion of Escherichia coli expressing YadA, an adhesive protein from Yersinia so-called Yersinia adhesin. The use of design of experiments techniques allowed for successfully attaining a PET material with a high bacterial anti-adhesiveness, using a simple grafting approach.This work was supported by the ViBrANT project that received funding from the EU Horizon 2020 Research and Innovation Programme under the Marie Sklowdowska-Curie, Grant agreement no 765042 and the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020.info:eu-repo/semantics/publishedVersio

    Central Inhibition of Tumor Necrosis Factor Alpha Reduces Hypertension by Attenuating Oxidative Stress in the Rostral Ventrolateral Medulla in Renovascular Hypertensive Rats

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    Inflammation in the central nervous system is being considered a key player linked to neurogenic hypertension. Using combined in vivo and in vitro approaches, we investigated the effects of central inhibition of TNF-α on blood pressure, sympathetic tone, baroreflex sensitivity, and oxidative stress in the rostral ventrolateral medulla (RVLM) of rats with 2-kidney-1-clip (2K1C) renovascular hypertension. Continuous infusion of pentoxifylline, a TNF-α inhibitor, into the lateral ventricle of the brain for 14 consecutive days reduced blood pressure and improved baroreflex sensitivity in renovascular hypertensive rats. Furthermore, central TNF-α inhibition reduced sympathetic modulation and blunted the increased superoxide accumulation in the RVLM of 2K1C rats. Our findings suggest that TNF-α play an important role in the maintenance of sympathetic vasomotor tone and increased oxidative stress in the RVLM during renovascular hypertension

    Recombinant Saccharomyces cerevisiae as a microbial biocatalyst for the one-step production of prebiotic fructooligosaccharides

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    Fructooligosaccharides (FOS) are widely consumed prebiotics with proven beneficial effects on both human and animal health. As a result, alternative production processes with high-efficiency have been an increasing focus of interest by both academy and industry. In this work, a in vivo bioprocess approach was successfully developed for one-step production of FOS from sucrose fermentation by recombinant yeast. Saccharomyces cerevisiae YIL162W lacking the gene responsible for sucrose hydrolysis (suc2) was transformed to express the -fructofuranosidase (Ffase) INV gene from Schwanniomyces occidentalis (clone L196), and its mutated version containing a serine instead of a leucine at position 196 (clone S196), under the inducible GAL1 promotor. Clone S196 presented a 2.75-fold higher sucrolytic activity (22±3 U.mL-1), while clone L196 presented a higher efficiency towards FOS production, producing mainly 6-kestose (76±3 g.L-1) and 1-kestose (1.6±0.6 g.L- 1) after 24 h of fermentation at 30 °C and 200 rpm, in a medium containing 300 g/L of sucrose. Attending the potential of process simplification and cost-reduction, the Ffase INV gene was then expressed under the glyceraldehyde-3-phosphate dehydrogenase (GPD) constitutive promoter (clone GPD L196), resulting in a maximum FOS production of 61±4 g.L-1 ( 56±3 g.L-1 of 6-kestose and 5±31 of fructosylnystose) after 48 h of fermentation using 300 g/L of sucrose. Interestingly, the total amount of undesired glucose and fructose present in the media whenever the maximal FOS production was achieved, was 9 times lower with the GDP promoter (5.5±0.9 g.L-1). The present work demonstrates the high potential of this bioprocess approach for industrial production of prebiotic FOS in a single step. Nevertheless, there is still room for yield improvement in future work, namely through bioprocess optimization.FCT under the scope of the strategic funding of UID/BIO/04469/2019 unit and the project FoSynBio (POCI-01-0145-FEDER-029549). The authors also acknowledge BioTecNorte operation (NORTE-01- 0145-FEDER-000004) and the project MultiBiorefinery (POCI-01-0145-FEDER-016403) funded by the European Regional Development Fund under the scope of Norte2020 – Programa Operacional Regional do Norteinfo:eu-repo/semantics/publishedVersio

    Zymomonas mobilis: a promising microorganism for prebiotic production

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    Zymomonas mobilis (ZM) is an ethanologenic bacterium with outstanding characteristics which makes it an interesting chassis for the biotechnological production of prebiotics. Fructooligosaccharides (FOS) are promising prebiotics in the increasing market of functional food. In this work, a Box-Behnken design approach was used to optimize the medium composition and maximize the FOS content. Under optimal conditions, 45.3 g/L of FOS were obtained. Sucrose was the most significant variable; thus, its concentration was further increased to 350 g/L leading to a 1.13-fold enhance in FOS titer. Afterwards, a scale-up to bioreactor was performed resulting in a high yield, content and productivity of FOS (58 %, 156.5 g/L 4.8 g/L h). Furthermore, 45 g/L of sorbitol and 8 g/L of levan were also produced. After purification of the FOS mixture through an activated charcoal column, an in vitro model using human fecal inoculum was used to assess its prebiotic potential. The results suggest that the produced prebiotic mixture has potential to be used to improve the human health. The present work describes for the first time the production of a prebiotic mixture with ZM ZM4 in an in vivo single-step approach that has potential to be commercialized as functional food ingredient.JoĂŁo Rainha, Beatriz B. Cardoso and Daniela Gomes acknowledge their grants (UMINHO/BPD/4/2019, SFRH/BD/138325/2018, SFRH/BD/132324/2017, and SFRH/BD/04433/2020, respectively) from Portuguese Foundation for Science and Technology (FCT). The study received financial support from Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit and the project FoSynBio (POCI-01-0145-FEDER-029549).info:eu-repo/semantics/publishedVersio

    Quantification of cell cycle kinetics by EdU (5-ethynyl-2â€Č-deoxyuridine)-coupled-fluorescence-intensity analysis

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    Copyright: Pereira et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License 3.0 (CC BY3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.We propose a novel single-deoxynucleoside-based assay that is easy to perform and provides accurate values for the absolute length (in units of time) of each of the cell cycle stages (G1, S and G2/M). This flow-cytometric assay takes advantage of the excellent stoichiometric properties of azide-fluorochrome detection of DNA substituted with 5-ethynyl-2'-deoxyuridine (EdU). We show that by pulsing cells with EdU for incremental periods of time maximal EdU-coupled fluorescence is reached when pulsing times match the length of S phase. These pulsing times, allowing labelling for a full S phase of a fraction of cells in asynchronous populations, provide accurate values for the absolute length of S phase. We characterized additional, lower intensity signals that allowed quantification of the absolute durations of G1 and G2 phases.Importantly, using this novel assay data on the lengths of G1, S and G2/M phases are obtained in parallel. Therefore, these parameters can be estimated within a time frame that is shorter than a full cell cycle. This method, which we designate as EdU-Coupled Fluorescence Intensity (E-CFI) analysis, was successfully applied to cell types with distinctive cell cycle features and shows excellent agreement with established methodologies for analysis of cell cycle kinetics.JoĂŁo A. Ferreira received support from a Calouste Gulbenkian Foundation grant (96526) and Pedro Pereira is an FCT fellow (SFRH/BD/45502/2008). Evguenia Bekman is the recipient of an IMM-Lisbon fellowship (iMM/BPD/60-2016; project PTDC/BEXBCM/5899/2014).info:eu-repo/semantics/publishedVersio

    CaracterĂ­sticas fĂ­sicas e quĂ­micas da graviola

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    In this work, fruits from soursoup (Annona muricata L.) obtained in Fortaleza, Cearå, Brazil, were used. Physical measurements were made on the homogenized pulp of raw and ripe fruits to evaluate their industrial yield. Chemical and physical determinations were made in order to know the chemical composition of the fruits. Liquid gas chromatography was used to evaluate the percentage of the fatty acid composition of the lipid fraction of the soursoup seeds.Neste trabalho foram empregados frutos da gravioleira (Annona muricata L.), provenientes do mercado hortifrutigranjeiro de Fortaleza, Cearå. Realizaram-se medidas físicas em 30 frutos maduros. As determinaçÔes das características químicas e físicas foram realizadas na polpa homogeneizada de frutos verdes e maduros. Procedeu-se a estudo no óleo da semente da graviola através de anålise cromatogråfica em fase gasosa, determinando-se a percentagem de åcidos graxos presentes na fração lipídica

    New 99mTc-Labeled Digitoxigenin Derivative for Cancer Cell Identification

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    In recent years, cardiac glycosides (CGs) have been investigated as potential antiviral and anticancer drugs. Digitoxigenin (DIG) and other CGs have been shown to bind and inhibit Na+/K+-adenosinetriphosphatase (ATPase). Tumor cells show a higher expression rate of the Na+/K+-ATPase protein or a stronger affinity towards the binding of CGs and are therefore more prone to CGs than non-tumor cells. Cancer imaging techniques using radiotracers targeted at specific receptors have yielded successful results. Technetium-99m (99mTc) is one of the radionuclides of choice to radiolabel pharmaceuticals because of its favorable physical and chemical properties along with reasonable costs. Herein, we describe a new Na+/K+-ATPase targeting radiotracer consisting of digitoxigenin and diethylenetriaminepentaacetic acid (DTPA), a bifunctional chelating ligand used to prepare 99mTc-labeled complexes, and its evaluation as an imaging probe. We report the synthesis and characterization of the radiolabeled compound including stability tests, blood clearance, and biodistribution in healthy mice. Additionally, we investigated the binding of the compound to A549 human non-small-cell lung cancer cells and the inhibition of the Na+/K+-ATPase by the labeled compound in vitro. The 99mTc-labeled DTPA–digitoxigenin (99mTc-DTPA–DIG) compound displayed high stability in vitro and in vivo, a fast renal excretion, and a specific binding towards A549 cancer cells in comparison to non-tumor cells. Therefore, 99mTc-DTPA–DIG could potentially be used for non-invasive visualization of tumor lesions by means of scintigraphic imaging

    The Gaia spectrophotometric standard stars survey - III. Short-term variability monitoring

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    We present the results of the short-term constancy monitoring of candidate Gaia Spectrophotometric Standard Stars (SPSS). We obtained time series of typically 1.24 h - with sampling periods from 1-3 min to a few hours, depending on the case - to monitor the constancy of our candidate SPSS down to 10 mmag, as required for the calibration of Gaia photometric data. We monitored 162 out of a total of 212 SPSS candidates. The observing campaign started in 2006 and finished in 2015, using 143 observing nights on nine different instruments covering both hemispheres. Using differential photometry techniques, we built light curves with a typical precision of 4 mmag, depending on the data quality. As a result of our constancy assessment, 150 SPSS candidates were validated against short-term variability, and only 12 were rejected because of variability including some widely used flux standards such as BD+174708, SA 105-448, 1740346, and HD 37725

    Action of cholecalciferol and alpha-tocopherol on Staphylococcus aureus efflux pumps

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    Alpha-tocopherol is one the most abundant and biologically active isoforms of vitamin E. This compound is a potent antioxidant and one of most studied isoforms of vitamin E. Vitamin D3 (cholecalciferol) is an important nutrient for calcium homeostasis and bone health, that has also been recognized as a potent modulator of the immune response. Methicillin-resistant Staphylococcus aureus (MRSA) is the most important causative agent of both nosocomial and community-acquired infections. The aim of this study was to evaluate the inhibitory effect of alpha-tocopherol and cholecalciferol on both S. aureus and multidrug resistant S. aureus efflux pumps. The RN4220 strain has the plasmid pUL5054 that is the carrier of gene that encodes the macrolide resistance protein (an efflux pump) MsrA; the IS-58 strain possesses the TetK tetracycline efflux protein in its genome and the 1199B strain resists to hydrophilic fluoroquinolones via a NorA-mediated mechanism. The antibacterial activity was evaluated by determining the Minimal Inhibitory Concentration (MIC) and a possible inhibition of efflux pumps was associated to a reduction of the MIC. In this work we observed that in the presence of the treatments there was a decrease in the MIC for the RN4220 and IS-58 strains, suggesting that the substances presented an inhibitory effect on the efflux pumps of these strains. Significant efforts have been done to identify efflux pump inhibitors (EPIs) from natural sources and, therefore, the antibacterial properties of cholecalciferol and alphatocopherol might be attributed to a direct effect on the bacterial cell depending on their amphipathic structure
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