237 research outputs found

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    Pristine Multi-walled carbon nanotubes for a rapid and efficient plasmid DNA clarification

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    Therapeutic approaches based on nucleic acids to modulate cell activity have recently gained attention. These molecules arise from complex biotechnological processes, requiring effective manufacturing strategies, high purity, and precise quality control to be used as biopharmaceuticals. One of the most critical and time-consuming steps for nucleic acids-based biotherapeutics manufacturing is their purification, mainly due to the complexity of the extracts. In this study, a simple, efficient, and reliable method to isolate and clarify plasmid DNA (pDNA) from complex samples is described. The method is based on the selective capture of RNA and other impurities, using pristine carbon nanotubes (CNTs). Multi-walled CNTs (MWCNTs) with different diameters were studied to determine their adsorption capacity and to address their ability to interact and distinguish between nucleic acids. The results revealed that MWCNTs preferentially interact with RNA and that smaller MWCNTs present a higher adsorption capacity, as expected by the higher specific surface area. Overall, this study showed that MWCNTs significantly reduce the levels of impurities, namely RNA, gDNA, and proteins, by approximately 83.6 % compared to their initial level, enabling the recovery of clarified pDNA in solution while maintaining its stability throughout the recovery process. This method facilitates the pre-purification of pDNA for therapeutic applications.publishe

    Frequência De Anticorpos Anti-toxoplasma Gondii Em Cães Com Sinais Clínicos Compatíveis Com Toxoplasmose

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    The aim of this study was to detect antibodies against T. gondii in dogs with clinical signs compatible with toxoplasmosis attended in a veterinary hospital. A serological survey was performed in 598 dogs from 1993 to 2013. The IgG antibodies survey against T. gondii was carried out by means of Indirect Fluorescence Antibodies Test (IFAT); samples with titers >16 were considered positive. Among the dogs with clinical signs, 259 (43,31%) were positive for T. gondii with titers varying between 16 to 4096; among the healthy animals, 79 (22.25%) were reagents. The most frequent signals were: neurological (30.43%) and uveitis (8.03%). Among variables race, gender, and age, only the last one affected the observed results with greater frequency f seropositive in elderly dogs. © 2016, Cienc. anim. bras., Goiânia. All rights reserved.17464064

    Cryptosporidium Spp. And Giardia Spp. In Feces And Water And The Associated Exposure Factors On Dairy Farms

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    The aims of this study were to verify the prevalence of Cryptosporidium spp. and Giardia spp. in animal feces and drinking water on dairy farms and to identify a possible relation between the exposure factors and the presence of these parasites. Fecal samples from cattle and humans and water samples were collected on dairy farms in Paraná, Brazil. Analysis of (oo)cysts in the feces was performed by the modified Ziehl-Neelsen staining and centrifugal flotation in zinc sulfate. Test-positive samples were subjected to nested PCR amplification of the 18SSU ribosomal RNA gene for identification of Cryptosporidium and Giardia and of the gp60 gene for subtyping of Cryptosporidium. Microbiological analysis of water was carried out by the multiple-tube method and by means of a chromogenic substrate, and parasitological analysis was performed on 31 samples by direct immunofluorescence and nested PCR of the genes mentioned above. Identification of the species of Cryptosporidium was performed by sequencing and PCR with analysis of restriction fragment length polymorphisms. The prevalence of Giardia and Cryptosporidium was higher in calves than in adults. Among the samples of cattle feces, Cryptosporidium parvum was identified in 41 (64%), C. ryanae in eight (12.5%), C. bovis in four (6.3%), C. andersoni in five (7.8%), and a mixed infection in 20 samples (31.3%). These parasites were not identified in the samples of human feces. Thermotolerant coliform bacteria were identified in 25 samples of water (45.5%). Giardia duodenalis and C. parvum were identified in three water samples. The gp60 gene analysis of C. parvum isolates revealed the presence of two strains (IIaA20G1R1 and IIaA17G2R2) in the fecal samples and one (IIaA17G2R1) in the water samples. The presence of coliforms was associated with the water source, structure and degradation of springs, rain, and turbidity. The prevalence of protozoa was higher in calves up to six months of age. C. parvum and G. duodenalis were identified in the water of dairy farms, as were thermotolerant coliforms; these findings point to the need for guidance on handling of animals, preservation of water sources, and water treatment. © 2017 Toledo et al.This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.12

    Filtering informal learning in everyday life: invoking ordinariness and moving to civic engagement

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    This article explores the role of informal learning from television as it is anchored within the ordinariness of daily life. It examines the consequences for pedagogy and civic engagement, questioning how informal learning from television can enhance civic engagement. For many, this learning was localized through personalized and interpersonal relations of everyday life. Learning was not viewed as a distant institutional force, but as an embedded part of an ordinary life. The invoking of ordinariness rendered the relationship between learning and civic engagement unproblematic. Learning was localized in subjective terms for self-identity and interpersonal relations rather than critically reflecting on the power structures of everyday life

    Prospects for Observations of Pulsars and Pulsar Wind Nebulae with CTA

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    The last few years have seen a revolution in very-high gamma-ray astronomy (VHE; E>100 GeV) driven largely by a new generation of Cherenkov telescopes (namely the H.E.S.S. telescope array, the MAGIC and MAGIC-II large telescopes and the VERITAS telescope array). The Cherenkov Telescope Array (CTA) project foresees a factor of 5 to 10 improvement in sensitivity above 0.1 TeV, extending the accessible energy range to higher energies up to 100 TeV, in the Galactic cut-off regime, and down to a few tens GeV, covering the VHE photon spectrum with good energy and angular resolution. As a result of the fast development of the VHE field, the number of pulsar wind nebulae (PWNe) detected has increased from one PWN in the early '90s to more than two dozen firm candidates today. Also, the low energy threshold achieved and good sensitivity at TeV energies has resulted in the detection of pulsed emission from the Crab Pulsar (or its close environment) opening new and exiting expectations about the pulsed spectra of the high energy pulsars powering PWNe. Here we discuss the physics goals we aim to achieve with CTA on pulsar and PWNe physics evaluating the response of the instrument for different configurations.Comment: accepted for publication in Astroparticle Physic

    Debate sobre o artigo de Narvai et al.

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    English title: Debate on the paper by Narvai et al.Margareth Crisóstomo Portela & Mauricio Teixeira Leite de Vasconcello
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