24 research outputs found

    A facile chemical conversion synthesis of Sb2S3 nanotubes and the visible light-driven photocatalytic activities

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    We report a simple chemical conversion and cation exchange technique to realize the synthesis of Sb2S3 nanotubes at a low temperature of 90°C. The successful chemical conversion from ZnS nanotubes to Sb2S3 ones benefits from the large difference in solubility between ZnS and Sb2S3. The as-grown Sb2S3 nanotubes have been transformed from a weak crystallization to a polycrystalline structure via successive annealing. In addition to the detailed structural, morphological, and optical investigation of the yielded Sb2S3 nanotubes before and after annealing, we have shown high photocatalytic activities of Sb2S3 nanotubes for methyl orange degradation under visible light irradiation. This approach offers an effective control of the composition and structure of Sb2S3 nanomaterials, facilitates the production at a relatively low reaction temperature without the need of organics, templates, or crystal seeds, and can be extended to the synthesis of hollow structures with various compositions and shapes for unique properties

    Reassortment Patterns in Swine Influenza Viruses

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    Three human influenza pandemics occurred in the twentieth century, in 1918, 1957, and 1968. Influenza pandemic strains are the results of emerging viruses from non-human reservoirs to which humans have little or no immunity. At least two of these pandemic strains, in 1957 and in 1968, were the results of reassortments between human and avian viruses. Also, many cases of swine influenza viruses have reportedly infected humans, in particular, the recent H1N1 influenza virus of swine origin, isolated in Mexico and the United States. Pigs are documented to allow productive replication of human, avian, and swine influenza viruses. Thus it has been conjectured that pigs are the “mixing vessel” that create the avian-human reassortant strains, causing the human pandemics. Hence, studying the process and patterns of viral reassortment, especially in pigs, is a key to better understanding of human influenza pandemics. In the last few years, databases containing sequences of influenza A viruses, including swine viruses, collected since 1918 from diverse geographical locations, have been developed and made publicly available. In this paper, we study an ensemble of swine influenza viruses to analyze the reassortment phenomena through several statistical techniques. The reassortment patterns in swine viruses prove to be similar to the previous results found in human viruses, both in vitro and in vivo, that the surface glycoprotein coding segments reassort most often. Moreover, we find that one of the polymerase segments (PB1), reassorted in the strains responsible for the last two human pandemics, also reassorts frequently

    Expression of toll-like receptor -7 and -9 in B cell subsets from patients with primary Sjögren's syndrome

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    Introduction: Sjögren’s syndrome (SS) is a rheumatic autoimmune disease characterized by inflammation of exocrine glands. As autoantibodies are present in a majority of patients, B cells have been suggested to play an important role in onset and development of the disease. Toll-like receptors (TLRs) are pattern recognition receptors triggering innate immune responses. Since an increased expression of TLRs has been detected in other rheumatic diseases the purpose of this study was to explore TLRs in B cells of SS patients. Methods: The expression of TLR-7 and -9 in B cell subsets of 25 patients with primary SS (pSS) and 25 healthy controls was analysed in peripheral blood using flow cytometry and real time quantitative PCR. Results: We detected similar levels of CD19+ B cells in pSS patients and healthy controls. An increased number of naïve B cells, as well as fewer pre-switched memory B cells were found in pSS patients. No significant differences were observed in TLR-7 and -9 expression in B cells between pSS patients and healthy controls. Conclusion: This study shows that pSS patients have an alteration in the B cell subpopulation composition compared to controls, with less pre-switched memory B cells and more naïve B cells. We did not detect any significant disparities in TLR-7 and -9 expression between the two groups

    New Directions in Intercultural Early Education in Australia

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    Early education in Australia encompasses both early education and care(ECEC) and the early years of school. Educational approaches to cultural and linguistic diversity have varied not only by sector but also by jurisdiction based on distinct curriculum frameworks and policies. In Australian early education, provision for cultural and linguistic diversity has been framed largely by multicultural discourse, as defined by a complex history of progressive, yet often superficial reforms. Current initiatives serve to change this trajectory and the positioning of stakeholders. The incorporation of intercultural rather than multicultural approaches offers new possibilities for early education and directs attention to real challenges for ECEC. They re-position Aboriginal and Torres Strait Islanders as the First Australians, and direct attention to both Australia’s social, cultural and linguistic diversity and to the role of early childhood educators in enacting more inclusive pedagogies. Challenges yet to be addressed include the cultural understanding of Australian early childhood educators, particularly those who identify as Anglo- Australian, deeper policy enactment in pedagogic practice and negotiation with diverse families and communities. This paper will address the historical and current policy contexts of intercultural early education in Australia, the development of intercultural initiatives, and emerging issues as national policies are introduced. The discussion draws on responses to intercultural early education in New Zealand and Canada to consider approaches to intercultural priorities in Australia. The paper will attend predominantly to Aboriginal and Torres Strait Islander perspectives as a core element of change in Australian early childhood policy, focusing on ECEC
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