126 research outputs found

    The stability of external walls in panel construction

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    Evaluation of Antithrombogenicity and Hydrophilicity on Zein-SWCNT Electrospun Fibrous Nanocomposite Scaffolds

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    Design of blood compatible surfaces is required to minimize platelet surface interactions and increase the thromboresistance of foreign surfaces when they are used as biomaterials especially for artificial blood prostheses. In this study, single wall carbon nanotubes (SWCNTs) and Zein fibrous nanocomposite scaffolds were fabricated by electrospinning and evaluated its antithrombogenicity and hydrophilicity. The uniform and highly smooth nanofibers of Zein composited with different SWCNTs content (ranging from 0.2 wt% to 1 wt%) were successfully prepared by electrospinning method without the occurrence of bead defects. The resulting fiber diameters were in the range of 100–300 nm without any beads. Composite nanofibers with and without SWCNT were characterized through a variety of methods including scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, and tensile mechanical testing. The water uptake and retention ability of composite scaffolds decreased whereas thermal stability increased with an addition of SWCNTs. Hemolytic property and platelet adhesion ability of the nanocomposite (Zein-SWCNTs) were explored. These observations suggest that the novel Zein-SWCNTs composite scaffolds may possibly hold great promises as useful antithrombotic material and promising biomaterials for tissue engineering application

    Development of a bovine X chromosome linkage group and painting probes to assess cattle, sheep, and goat X chromosome segment homologies

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    The X chromosome linkage group is conserved in placental mammals. However, X chromosome morphological differences, due to internal chromosome rearrangements, exist among mammalian species. We have developed bovine chromosome painting probes for Xp and Xq to assess segment homologies between the submetacentric bovine X chromosome and the acrocentric sheep and goat X chromosomes. These painting probes and their corresponding DNA libraries were developed by chromosome micromanipulation, DNA micropurification, microcloning, and PCR amplification. The bovine Xp painting probe identified an interstitially located homologous segment in the sheep and goat Xq region, most probably resulting from chromosome inversion. Ten type II (microsatellite) markers obtained from the bovine Xq library and five other X chromosome assigned, but unlinked, markers were used to generate a linkage map for Xq spanning 89.4 centimorgans. The chromosome painting probes and molecular markers generated in this study would be useful for comparative mapping and tracing of internal X chromosome rearrangements in all ruminant species and would contribute to the understanding of mammalian sex chromosome evolution

    Microevolution of serial clinical isolates of Cryptococcus neoformans var. grubii and C. gattii

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    This is the final version. Available from the publisher via the DOI in this record.The pathogenic species of Cryptococcus are a major cause of mortality owing to severe infections in immunocompromised as well as immunocompetent individuals. Although antifungal treatment is usually effective, many patients relapse after treatment, and in such cases, comparative analyses of the genomes of incident and relapse isolates may reveal evidence of determinative, microevolutionary changes within the host. Here, we analyzed serial isolates cultured from cerebrospinal fluid specimens of 18 South African patients with recurrent cryptococcal meningitis. The time between collection of the incident isolates and collection of the relapse isolates ranged from 124 days to 290 days, and the analyses revealed that, during this period within the patients, the isolates underwent several genetic and phenotypic changes. Considering the vast genetic diversity of cryptococcal isolates in subSaharan Africa, it was not surprising to find that the relapse isolates had acquired different genetic and correlative phenotypic changes. They exhibited various mechanisms for enhancing virulence, such as growth at 39°C, adaptation to stress, and capsule production; a remarkable amplification of ERG11 at the native and unlinked locus may provide stable resistance to fluconazole. Our data provide a deeper understanding of the microevolution of Cryptococcus species under pressure from antifungal chemotherapy and host immune responses. This investigation clearly suggests a promising strategy to identify novel targets for improved diagnosis, therapy, and prognosis.Wellcome TrustNational Institute of Allergy and Infectious Disease

    Genome Evolution and Innovation across the Four Major Lineages of Cryptococcus gattii

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    We acknowledge the Broad Institute Sequencing Platform and Imperial College London for generating the DNA sequence described here (and R265 Illumina sequences described previously [4]). We thank Sinéad Chapman for coordinating sequencing at the Broad Institute and Margaret Priest for assistance in submitting assemblies to NCBI. This project was supported by the National Human Genome Research Institute, grant no. U54HG003067. R.A.F. is supported by the Wellcome Trust. R.C.M. is supported by the Lister Institute for Preventive Medicine, the Medical Research Council UK, and the European Research Council.Peer reviewedPublisher PD

    Microevolution of Serial Clinical Isolates of Cryptococcus neoformans var. grubii and C. gattii

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    We thank the Broad Institute Sequencing Platform for generating the Illumina sequences. We thank Chen-Hsin Yu for helping on the data processing of the phenotypic tests. We acknowledge the South African National Institute for Communicable Diseases’ GERMS-SA surveillance network through which these isolates were originally collected. This project has been funded in whole or in part by the following U.S. Health and Human Services grants from the National Institute of Allergy and Infectious Diseases: U19 AI110818 (Broad Institute), R01 AI93257 (J.R.P.), R01 AI73896 (J.R.P.), and R01 AI025783 (T.G.M.). R.A.F. was supported by the Wellcome Trust. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The content is solely our responsibility and does not necessarily represent the official views of the funders. The use of product names in this manuscript does not imply their endorsement by the U.S. Department of Health and Human Services. The findings and conclusions in this article are those of the authors and do not necessarily represent the views of the CDC.Peer reviewedPublisher PD

    Genome Diversity, Recombination, and Virulence across the Major Lineages of Paracoccidioides

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    We thank Angela Restrepo, Rosana Puccia, Zoilo Pires de Camargo, and Maria Sueli Felipe for kindly providing the isolates for this study. This project has been funded in whole or in part with federal funds from the National Institute of Allergy and Infectious Diseases, National Institutes of Health, Department of Health and Human Services, under contract no. HHSN272200900018C. This work was partly supported by Colciencias via the grants “A Gene Atlas for Human Pathogenic Fungi” (122256934875) and “A Comprehensive Genomic and Transcriptomic Analysis of Dimorphic Human Pathogen Fungi and Its Relation with Virulence” (221365842971) and by the Universidad de Antioquia via a “Sostenibilidad 2015/2016” grant. Colciencias National Doctorate Program funding supported J.F.M.; Enlaza Mundos partly supported his fellowship. The Wellcome Trust supported R.A.F.Peer reviewedPublisher PD
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