948 resultados para MICROBIAL LEAKAGE
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Nine ruminally cannulated cows fed different energy sources were used to evaluate an avianderived polyclonal antibody preparation against specific ruminal bacteria and monensin on microbial community diversity. The experimental design was three Latin squares 3 x 3 distinguished by the main energy source in the diet [dry-ground corn grain, high moisture corn silage or citrus pulp]. Inside each Latin square, animals received one of the feed additives per period [control, monensin or polyclonal antibody preparation]. Each period lasted 21 days where 20 were used for treatments adaptation and the last one for sampling collection. Microbial diversity was evaluated by protozoa counts and denaturing gradient gel electrophoresis. Polyclonal antibodies plus citrus pulp (CiPu) addition in the diet resulted in an increase of relative counting of Isotricha protozoa that indicates a possible effect on this ruminal ciliate population. In general lines, in the present experiment, it was not possible to assign that there was a pattern in the structures of amplification of Bacteria and Archaea communities of the ruminal content. Oral passive immunization is a technology that arises as an effective alternative for feed additive production. Further research is still necessary to better understand its mechanisms of action.
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Objectives: This in vitro study was established to examine whether visfatin thought to be a link between periodontitis and obesity is produced by periodontal ligament (PDL) cells and, if so, whether its synthesis is modulated by microbial and/or biomechanical signals. Materials and methods: PDL cells seeded on BioFlex® plates were exposed to the oral pathogen Fusobacterium nucleatum ATCC 25586 and/or subjected to biomechanical strain for up to 3 days. Gene expression of visfatin and toll-like receptors (TLR) 2 and 4 was analyzed by RT-PCR, visfatin protein synthesis by ELISA and immunocytochemistry, and NFκB nuclear translocation by immunofluorescence. Results: F. nucleatum upregulated the visfatin expression in a dose- and time-dependent fashion. Preincubation with neutralizing antibodies against TLR2 and TLR4 caused a significant inhibition of the F. nucleatum-upregulated visfatin expression at 1 day. F. nucleatum stimulated the NFκB nuclear translocation. Biomechanical loading reduced the stimulatory effects of F. nucleatum on visfatin expression at 1 and 3 days and also abrogated the F. nucleatum-induced NFκB nuclear translocation at 60 min. Biomechanical loading inhibited significantly the expression of TLR2 and TLR4 at 3 days. The regulatory effects of F. nucleatum and/or biomechanical loading on visfatin expression were also observed at protein level. Conclusions: PDL cells produce visfatin, and this production is enhanced by F. nucleatum. Biomechanical loading seems to be protective against the effects of F. nucleatum on visfatin expression. Clinical relevance: Visfatin produced by periodontal tissues could play a major role in the pathogenesis of periodontitis and the interactions with obesity and other systemic diseases. © 2013 Springer-Verlag Berlin Heidelberg.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The objective of this study was to use 15N to label microbial cells to allow development of equations for estimating the microbial contamination in ruminal in situ incubation residues of forage produced under tropical conditions. A total of 24 tropical forages were ruminal incubated in 3 steers at 3 separate times. To determine microbial contamination of the incubated residues, ruminal bacteria were labeled with 15N by continuous intraruminal infusion 60 h before the first incubation and continued until the last day of incubation. Ruminal digesta was collected for the isolation of bacteria before the first infusion of 15N on adaptation period and after the infusion of 15N on collection period. To determine the microbial contamination of CP fractions, restricted models were compared with the full model using the model identity test. A value of the corrected fraction A was estimated from the corresponding noncorrected fraction by this equation: Corrected A fraction (ACPC) = 1.99286 + 0.98256 × A fraction without correction (ACPWC). The corrected fraction B was estimated from the corresponding noncorrected fraction and from CP, NDF, neutral detergent insoluble protein (NDIP), and indigestible NDF (iNDF) using the equation corrected B fraction (BCPC) = -17.2181 - 0.0344 × fraction B without correction (BCPWC) + 0.65433 × CP + 1.03787 × NDF + 2.66010 × NDIP - 0.85979 × iNDF. The corrected degradation rate of B fraction (kd)was estimated using the equation corrected degradation rate of B fraction (kdCPC) = 0.04667 + 0.35139 × degradation rate of B fraction without correction (kdCPWC) + 0.0020 × CP - 0.00055839 × NDF - 0.00336 × NDIP + 0.00075089 × iNDF. This equation was obtained to estimate the contamination using CP of the feeds: %C = 79.21 × (1 - e-0.0555t) × e-0.0874CP. It was concluded that A and B fractions and kd of CP could be highly biased by microbial CP contamination, and therefore these corrected values could be obtained mathematically, replacing the use of microbial markers. The percentage of contamination and the corrected apparent degradability of CP could be obtained from values of CP and time of incubation for each feed, which could reduce cost and labor involved when using 15N. © 2013 American Society of Animal Science. All rights reserved.
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Fungi are a diverse group of organisms with an overall global number of 1.5 M up to 3.3 M species on Earth. Besides their ecological roles as decomposers, fungi are important in several aspects of applied research. Here, we review how culture collections may promote the knowledge on diversity, conservation and biotechnological exploitation of fungi. The impact of fungi diversity on biotechnological studies is discussed. We point out the major roles of microbial repositories, including fungal preservation, prospecting, identification, authentication and supply. A survey on the World Data Center for Microorganisms (WDCM) powered by the World Federation for Culture Collections and on the Genetic Heritage Management Council (CGEN) database revealed that 46 Brazilian culture collections registered in these databases are dedicate to preserving fungi. Most of these culture collections are located in the Southeast of Brazil. This scenario also demonstrates that Brazil has many collections focused on fungal strains, but the lack of up-to-date information in WDCM as well as of a solid national platform for culture collections registration do not allow accurate assessment of fungal preservation. © 2013 Elsevier Inc. All rights reserved.
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Pós-graduação em Ciências Biológicas (Microbiologia Aplicada) - IBRC
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Pós-graduação em Zootecnia - FCAV
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Pós-graduação em Odontologia Restauradora - ICT
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Because the agricultural use of tannery sludge may cause increased risks to soils, composting is recognized as one of the most suitable alternative for tannery sludge recycling. Experiments were conducted under field conditions to evaluate the effects of composted tannery sludge (CTS) on the soil microbial biomass and trace elements after two years of consecutive applications. The following five treatments were used: 0 (without CTS application), 5, 10, 20 and 40 ton ha-1 of CTS (dry basis). Soil samples were collected at 60 days after the CTS application at 0-20 cm depth. The CTS application promoted changes in the soil microbial biomass C (SMB-C) and N (SMB-N). In the first year, significant increases in the SMB-C and SMB-N were observed with the application of 10 ton ha-1. Furthermore, CTS application increased the Cr content in the soil after two years of application.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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The electromechanical impedance (EMI) technique has been successfully used in structural health monitoring (SHM) systems on a wide variety of structures. The basic concept of this technique is to monitor the structural integrity by exciting and sensing a piezoelectric transducer, usually a lead zirconate titanate (PZT) wafer bonded to the structure to be monitored and excited in a suitable frequency range. Because of the piezoelectric effect, there is a relationship between the mechanical impedance of the host structure, which is directly related to its integrity, and the electrical impedance of the PZT transducer, obtained by a ratio between the excitation and the sensing signals.This work presents a study on damage (leaks) detection using EMI based method. Tests were carried out in a rig water system built in a Hydraulic Laboratory for different leaks conditions in a metallic pipeline. Also, it was evaluated the influence of the PZT position bonded to the pipeline. The results show that leaks can effectively be detected using common metrics for damage detection such as RMSD and CCDM. Further, it was observed that the position of the PZT bonded to the pipes is an important variable and has to be controlled.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)