245 research outputs found

    Development of osteogenic cell sheets for bone tissue engineering applications

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    The use of scaffolds in combination with osteogenic cells has been the gold standard in bone tissue engineering strategies. These strategies have, however, in many cases failed to produce the desired results due to issues such as the immunogenicity of the biomaterials used and cell necrosis at the bulk of the scaffold related to deficient oxygen and nutrients diffusion. Here, we originally propose the use of cell sheet (CS) engineering as a possible way to overcome some of these obstacles. Osteogenic CSs were fabricated by culturing rat bone marrow stromal cells in thermoresponsive culture dishes. The CSs were recovered from the dishes using a low-temperature treatment and then were implanted subcutaneously in nude mice. New bone formation was verified from day 7 post-transplantation using X-ray, microcomputed tomography, and histological analysis. The presence of a vascularized marrow was also verified in the newly formed bone after 6 weeks of transplantation. Further, osteocytes were found in this newly formed tissue, supporting the conclusion that mature bone was formed after ectopically transplanting osteogenic CSs. These results therefore confirm the great potentiality of CS engineering to be used in bone tissue engineering applicationsThis study was partially supported by Formation of Innovation Center for Fusion of Advanced Technologies in the Special Coordination Funds for Promoting Science and Technology "Cell Sheet Tissue Engineering Center (CSTEC)" and the Global COE program, Multidisciplinary Education and Research Center for Regenerative Medicine (MER-CREM), from the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan.Financial support to R. P. Pirraco by the Portuguese Foundation for Science and Technology (FCT) through the PhD grant SFRH/BD/44893/2008 is also acknowledged

    Sazonalidade e qualidade do sêmen fresco e criopreservado de touros Pantaneiro e Nelore.

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    Made available in DSpace on 2017-12-06T23:24:00Z (GMT). No. of bitstreams: 1 160065451PB.pdf: 551242 bytes, checksum: d39ecb59ab27a3f54ae0ff8c4709a3d3 (MD5) Previous issue date: 2017-12-05bitstream/item/168292/1/1600-6545-1-PB.pd

    Performance of industrial scale hollow-fibre membranes in a submerged anaerobic MBR (HF-SAnMBR) system at mesophilic and psychrophilic conditions

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    The aim of this work was to evaluate the effect of temperature on the performance of industrial hollow-fibre (HF) membranes treating urban wastewater in a submerged anaerobic MBR system (SAnMBR). To this end, a demonstration plant with two commercial HF ultrafiltration membrane modules (PURON®, Koch Membrane Systems, PUR-PSH31) was operated at 20, 25 and 33 °C. The mixed liquor total solid (MLTS) level was a key factor affecting membrane permeability (K). K was higher under psychrophilic than mesophilic conditions when operating at similar transmembrane fluxes and MLTS, because the biomass activity of the psychrophilic mixed liquor was lower than the mesophilic mixed liquor. Thus, lower extracellular polymeric substances (EPSs) and soluble microbial products (SMPs) levels were observed at psychrophilic conditions, which affected not only the three-dimensional floc matrix, but also the fouling propensity. However, no chemical cleaning was needed during the experimental period (almost 1 year) because no irreversible fouling problems were detected.This research work has been supported by the Spanish Research Foundation (CICYT Projects CTM2008-06809-C02-01 and CTM2008-06809-C02-02, and MICINN FPI Grant BES-2009-023712) and Generalitat Valenciana (Projects GVA-ACOMP2010/130 and GVA-ACOMP2011/182), which are gratefully acknowledged.Robles Martínez, Á.; Ruano García, MV.; Ribes Bertomeu, J.; Ferrer, J. (2013). Performance of industrial scale hollow-fibre membranes in a submerged anaerobic MBR (HF-SAnMBR) system at mesophilic and psychrophilic conditions. Separation and Purification Technology. (104):290-296. https://doi.org/10.1016/j.seppur.2012.12.004S29029610

    Community profiling and gene expression of fungal assimilatory nitrate reductases in agricultural soil

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    Although fungi contribute significantly to the microbial biomass in terrestrial ecosystems, little is known about their contribution to biogeochemical nitrogen cycles. Agricultural soils usually contain comparably high amounts of inorganic nitrogen, mainly in the form of nitrate. Many studies focused on bacterial and archaeal turnover of nitrate by nitrification, denitrification and assimilation, whereas the fungal role remained largely neglected. To enable research on the fungal contribution to the biogeochemical nitrogen cycle tools for monitoring the presence and expression of fungal assimilatory nitrate reductase genes were developed. To the ∼100 currently available fungal full-length gene sequences, another 109 partial sequences were added by amplification from individual culture isolates, representing all major orders occurring in agricultural soils. The extended database led to the discovery of new horizontal gene transfer events within the fungal kingdom. The newly developed PCR primers were used to study gene pools and gene expression of fungal nitrate reductases in agricultural soils. The availability of the extended database allowed affiliation of many sequences to known species, genera or families. Energy supply by a carbon source seems to be the major regulator of nitrate reductase gene expression for fungi in agricultural soils, which is in good agreement with the high energy demand of complete reduction of nitrate to ammonium

    Ευρετικές προσεγγίσεις του μοναδιάστατου προβλήματος πακετοποίησης

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    Article 59.1, of the International Code of Nomenclature for Algae, Fungi, and Plants (ICN; Melbourne Code), which addresses the nomenclature of pleomorphic fungi, became effective from 30 July 2011. Since that date, each fungal species can have one nomenclaturally correct name in a particular classification. All other previously used names for this species will be considered as synonyms. The older generic epithet takes priority over the younger name. Any widely used younger names proposed for use, must comply with Art. 57.2 and their usage should be approved by the Nomenclature Committee for Fungi (NCF). In this paper, we list all genera currently accepted by us in Dothideomycetes (belonging to 23 orders and 110 families), including pleomorphic and non-pleomorphic genera. In the case of pleomorphic genera, we follow the rulings of the current ICN and propose single generic names for future usage. The taxonomic placements of 1261 genera are listed as an outline. Protected names and suppressed names for 34 pleomorphic genera are listed separately. Notes and justifications are provided for possible proposed names after the list of genera. Notes are also provided on recent advances in our understanding of asexual and sexual morph linkages in Dothideomycetes. A phylogenetic tree based on four gene analyses supported 23 orders and 75 families, while 35 families still lack molecular data
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