71 research outputs found

    Paecilomyces fumosoroseus blastospore production using liquid culture in a bioreactor

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    There are many advantages to using liquid cultures for the production of blastospores. These include mainly the processes of scale up which are relatively easy, as well as the control of parameters such astemperature, aeration and pH. In this work, we evaluated the production of Paecilomyces fumosoroseus blastospores using a low-cost liquid culture medium in a fermenter in comparison to a mediumcommonly used for this purpose, with regard to yield and viability of blastospores. The two media contained the same concentration of glucose but differed in N source (M1 containing casamino acidsand M2 provided with collagen peptone and yeast extract). Starting with an inoculum of 1x106 blastospores/ml, M2 medium produced 2x1010 blastospores/ml after incubation for 72 h at 520 rev/minagitation and 1 v/v/m (volume air/volume liquid.min) aeration, while only 2.4 x 108/ml were produced with M1. In addition, the microorganisms in medium M1 grew more slowly during log phase and reached an earlier plateau at 36 h fermentation. The medium containing collagen peptone and yeast extract is an excellent alternative for the production of P. fumosoroseus blastospores, providing lower cost, higher yield and shorter propagation time, but formulation does need to be improved

    Study of Beauveria bassiana growth, blastospore yield, desiccation-tolerance, viability and toxic activity using different liquid media

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    Beauveria bassiana was grown on three liquid media containing casaminoacids, corn steep liquor or peptone. After incubation, the blastospore counts reached 6.38 × 109 blastospores/ml, in the medium containing sucrose and corn steep liquor, which was significantly higher than the obtained with media containing casaminoacids or peptone. The medium containing corn steep liquor produced predominately submerged conidia, meanwhile the other media produced blastospores. The blastospores produced in the medium containing casaminoacids presented faster germination rates, than the blastospores produced in media containing corn steep liquor or peptone, although, after airdrying, were observed significant reductions on the viability of blastospores produced in the media composed by casaminoacids or peptone, but the spores produced in the medium with corn steep liquor were not affected. For storage of blastospores at 4 and 26°C after some months, the blastospores produced in the medium with casaminoacids showed the highest viability at 26°C, whereas at 4°C the counts of viable blastospores produced in medium containing corn steep liquor were significantly higher than the counts of blastospores produced in the other media with casaminoacids or peptone. The blastospores maintained for six months at 4°C showed high mortality against third-instar Plutella xylostella larvae.Key words: Beauveria bassiana, liquid media, fermentation, short times of propagation, biological control, entomopathogen fungus

    Effective Rheology of Bubbles Moving in a Capillary Tube

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    We calculate the average volumetric flux versus pressure drop of bubbles moving in a single capillary tube with varying diameter, finding a square-root relation from mapping the flow equations onto that of a driven overdamped pendulum. The calculation is based on a derivation of the equation of motion of a bubble train from considering the capillary forces and the entropy production associated with the viscous flow. We also calculate the configurational probability of the positions of the bubbles.Comment: 4 pages, 1 figur

    IL-1β Promotes TGF-β1 and IL-2 Dependent Foxp3 Expression in Regulatory T Cells

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    Earlier, we have shown that GM-CSF-exposed CD8α− DCs that express low levels of pro-inflammatory cytokines IL-12 and IL-1β can induce Foxp3+ Tregs leading to suppression of autoimmunity. Here, we examined the differential effects of IL-12 and IL-1β on Foxp3 expression in T cells when activated in the presence and absence of DCs. Exogenous IL-12 abolished, but IL-1β enhanced, the ability of GM-CSF-exposed tolerogenic DCs to promote Foxp3 expression. Pre-exposure of DCs to IL-1β and IL-12 had only a modest effect on Foxp3− expressing T cells; however, T cells activated in the absence of DCs but in the presence of IL-1β or IL-12 showed highly significant increase and decrease in Foxp3+ T cell frequencies respectively suggesting direct effects of these cytokines on T cells and a role for IL-1β in promoting Foxp3 expression. Importantly, purified CD4+CD25+ cells showed a significantly higher ability to maintain Foxp3 expression when activated in the presence of IL-1β. Further analyses showed that the ability of IL-1β to maintain Foxp3 expression in CD25+ T cells was dependent on TGF-β1 and IL-2 expression in Foxp3+Tregs and CD25− effectors T cells respectively. Exposure of CD4+CD25+ T cells to IL-1β enhanced their ability to suppress effector T cell response in vitro and ongoing experimental autoimmune thyroidits in vivo. These results show that IL-1β can help enhance/maintain Tregs, which may play an important role in maintaining peripheral tolerance during inflammation to prevent and/or suppress autoimmunity

    Approaches in biotechnological applications of natural polymers

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    Natural polymers, such as gums and mucilage, are biocompatible, cheap, easily available and non-toxic materials of native origin. These polymers are increasingly preferred over synthetic materials for industrial applications due to their intrinsic properties, as well as they are considered alternative sources of raw materials since they present characteristics of sustainability, biodegradability and biosafety. As definition, gums and mucilages are polysaccharides or complex carbohydrates consisting of one or more monosaccharides or their derivatives linked in bewildering variety of linkages and structures. Natural gums are considered polysaccharides naturally occurring in varieties of plant seeds and exudates, tree or shrub exudates, seaweed extracts, fungi, bacteria, and animal sources. Water-soluble gums, also known as hydrocolloids, are considered exudates and are pathological products; therefore, they do not form a part of cell wall. On the other hand, mucilages are part of cell and physiological products. It is important to highlight that gums represent the largest amounts of polymer materials derived from plants. Gums have enormously large and broad applications in both food and non-food industries, being commonly used as thickening, binding, emulsifying, suspending, stabilizing agents and matrices for drug release in pharmaceutical and cosmetic industries. In the food industry, their gelling properties and the ability to mold edible films and coatings are extensively studied. The use of gums depends on the intrinsic properties that they provide, often at costs below those of synthetic polymers. For upgrading the value of gums, they are being processed into various forms, including the most recent nanomaterials, for various biotechnological applications. Thus, the main natural polymers including galactomannans, cellulose, chitin, agar, carrageenan, alginate, cashew gum, pectin and starch, in addition to the current researches about them are reviewed in this article.. }To the Conselho Nacional de Desenvolvimento Cientfíico e Tecnológico (CNPq) for fellowships (LCBBC and MGCC) and the Coordenação de Aperfeiçoamento de Pessoal de Nvíel Superior (CAPES) (PBSA). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and COMPETE 2020 (POCI-01-0145-FEDER-006684) (JAT)

    Alignment of the ALICE Inner Tracking System with cosmic-ray tracks

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    37 pages, 15 figures, revised version, accepted by JINSTALICE (A Large Ion Collider Experiment) is the LHC (Large Hadron Collider) experiment devoted to investigating the strongly interacting matter created in nucleus-nucleus collisions at the LHC energies. The ALICE ITS, Inner Tracking System, consists of six cylindrical layers of silicon detectors with three different technologies; in the outward direction: two layers of pixel detectors, two layers each of drift, and strip detectors. The number of parameters to be determined in the spatial alignment of the 2198 sensor modules of the ITS is about 13,000. The target alignment precision is well below 10 micron in some cases (pixels). The sources of alignment information include survey measurements, and the reconstructed tracks from cosmic rays and from proton-proton collisions. The main track-based alignment method uses the Millepede global approach. An iterative local method was developed and used as well. We present the results obtained for the ITS alignment using about 10^5 charged tracks from cosmic rays that have been collected during summer 2008, with the ALICE solenoidal magnet switched off.Peer reviewe

    Particle identification in ALICE : a Bayesian approach

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    J/psi production as a function of charged-particle pseudorapidity density in p-Pb collisions at root s(NN)=5.02 TeV

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    We report measurements of the inclusive J/ψ yield and average transverse momentum as a function of charged-particle pseudorapidity density dNch/dη in p–Pb collisions at sNN=5.02TeV with ALICE at the LHC. The observables are normalised to their corresponding averages in non-single diffractive events. An increase of the normalised J/ψ yield with normalised dNch/dη, measured at mid-rapidity, is observed at mid-rapidity and backward rapidity. At forward rapidity, a saturation of the relative yield is observed for high charged-particle multiplicities. The normalised average transverse momentum at forward and backward rapidities increases with multiplicity at low multiplicities and saturates beyond moderate multiplicities. In addition, the forward-to-backward nuclear modification factor ratio is also reported, showing an increasing suppression of J/ψ production at forward rapidity with respect to backward rapidity for increasing charged-particle multiplicity

    清涼飮料税論

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    The production of J/\).psi\) and ψ(2S)\psi(2S) was measured with the ALICE detector in Pb-Pb collisions at the LHC. The measurement was performed at forward rapidity 2.5 < y < 4 \() down to zero transverse momentum \(p_{\rm T} in the dimuon decay channel. Inclusive J/\).psi\) yields were extracted in different centrality classes and the centrality dependence of the average pTp_{\rm T} is presented. The J/\).psi\) suppression, quantified with the nuclear modification factor RAAR_{\rm AA} , was studied as a function of centrality, transverse momentum and rapidity. Comparisons with similar measurements at lower collision energy and theoretical models indicate that the J/\).psi\) production is the result of an interplay between color screening and recombination mechanisms in a deconfined partonic medium, or at its hadronization. Results on the ψ(2S)\psi(2S) suppression are provided via the ratio of ψ(2S)\psi(2S) over J/\).psi\) measured in pp and Pb-Pb collisions
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