82 research outputs found

    Ion-beam nitriding of steels

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    A surface of a steel substrate is nitrided without external heating by exposing it to a beam of nitrogen ions under low pressure, a pressure much lower than that employed for ion-nitriding. An ion source is used instead of a glow discharge. Both of these features reduce the introduction of impurities into the substrate surface

    What defines livelihood vulnerability in rural semi‑arid areas? : evidence from Pakistan

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    In view of the enhanced vulnerability of semi-arid regions to climate change (IPCC AR5 Climate Change 2014: Mitigation of Climate Change) this paper attempts to identify the key determinants of vulnerability in three semi-arid districts of Pakistan using an indicator-based approach. Semi-arid lands in Pakistan predominantly feature irrigated agriculture. Results of IPCC–LVI show varying levels of vulnerability experienced by farmers in the three study sites. This paper uses the IPCC-Livelihood Vulnerability Index for developing site-specific vulnerability scores that portray the unique aspects that determine districts’ vulnerability to climate change such as water supply, access to information, rural poverty, health, education and genderUK's Department for International Development (DFID

    Downregulation of Integrin Ξ²4 Decreases the Ability of Airway Epithelial Cells to Present Antigens

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    Airway epithelial cells have been demonstrated to be accessory antigen presentation cells (APC) capable of activating T cells and may play an important role in the development of allergic airway inflammation of asthma. In asthmatic airways, loss of expression of the adhesion molecule integrin Ξ²4 (ITGB4) and an increase in Th2 inflammation bias has been observed in our previous study. Given that ITGB4 is engaged in multiple signaling pathways, we studied whether disruption of ITGB4-mediated cell adhesion may contribute to the adaptive immune response of epithelial cells, including their ability to present antigens, induce the activate and differentiate of T cells. We silenced ITGB4 expression in bronchial epithelial cells with an effective siRNA vector and studied the effects of ITGB4 silencing on the antigen presentation ability of airway epithelial cells. T cell proliferation and cytokine production was investigated after co-culturing with ITGB4-silenced epithelial cells. Surface expression of B7 homologs and the major histocompatibility complex (MHC) class II was also detected after ITGB4 was silenced. Our results demonstrated that silencing of ITGB4 resulted in impaired antigen presentation processes and suppressed T cell proliferation. Meanwhile, decrease in Th1 cytokine production and increase in Th17 cytokine production was induced after co-culturing with ITGB4-silenced epithelial cells. Moreover, HLA-DR was decreased and the B7 homologs expression was different after ITGB4 silencing. Overall, this study suggested that downregulation of ITGB4 expression in airway epithelial cells could impair the antigen presentation ability of these cells, which further regulate airway inflammation reaction in allergic asthma

    The use of simulation to prepare and improve responses to infectious disease outbreaks like COVID-19: practical tips and resources from Norway, Denmark, and the UK.

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    In this paper, we describe the potential of simulation to improve hospital responses to the COVID-19 crisis. We provide tools which can be used to analyse the current needs of the situation, explain how simulation can help to improve responses to the crisis, what the key issues are with integrating simulation into organisations, and what to focus on when conducting simulations. We provide an overview of helpful resources and a collection of scenarios and support for centre-based and in situ simulations

    The Menopause Taboo at Work: Examining Women’s Embodied Experiences of Menopause in the UK Police Service

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    This article contributes to the growing body of knowledge about gendered ageing at work through an examination of the embodied experiences of women undergoing menopause transition in the UK police service. Drawing on 1197 survey responses, providing both quantitative and qualitative data gathered across three police forces in 2017–18, the findings highlight the importance of a material-discursive approach that considers contextual influences on women’s bodily experiences. The article evidences gendered ageism and the penalty suffered by women whose ageing bodies fail to comply with an ideal worker norm. It makes an important contribution both to theorising embodiment, drawing in age as well as gender discourses, and to promoting a material-discursive approach that recognises the materiality of the body while also offering the potential for agency, reflection and resistance

    The Role of Alveolar Epithelial Cells in Initiating and Shaping Pulmonary Immune Responses: Communication between Innate and Adaptive Immune Systems

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    Macrophages and dendritic cells have been recognized as key players in the defense against mycobacterial infection. However, more recently, other cells in the lungs such as alveolar epithelial cells (AEC) have been found to play important roles in the defense and pathogenesis of infection. In the present study we first compared AEC with pulmonary macrophages (PuM) isolated from mice in their ability to internalize and control Bacillus Calmette-GuΓ©rin (BCG) growth and their capacity as APCs. AEC were able to internalize and control bacterial growth as well as present antigen to primed T cells. Secondly, we compared both cell types in their capacity to secrete cytokines and chemokines upon stimulation with various molecules including mycobacterial products. Activated PuM and AEC displayed different patterns of secretion. Finally, we analyzed the profile of response of AEC to diverse stimuli. AEC responded to both microbial and internal stimuli exemplified by TLR ligands and IFNs, respectively. The response included synthesis by AEC of several factors, known to have various effects in other cells. Interestingly, TNF could stimulate the production of CCL2/MCP-1. Since MCP-1 plays a role in the recruitment of monocytes and macrophages to sites of infection and macrophages are the main producers of TNF, we speculate that both cell types can stimulate each other. Also, another cell-cell interaction was suggested when IFNs (produced mainly by lymphocytes) were able to induce expression of chemokines (IP-10 and RANTES) by AEC involved in the recruitment of circulating lymphocytes to areas of injury, inflammation, or viral infection. In the current paper we confirm previous data on the capacity of AEC regarding internalization of mycobacteria and their role as APC, and extend the knowledge of AEC as a multifunctional cell type by assessing the secretion of a broad array of factors in response to several different types of stimuli

    Staphylococcus aureus enterotoxins induce IL-8 secretion by human nasal epithelial cells

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    BACKGROUND: Staphylococcus aureus produces a set of proteins which act both as superantigens and toxins. Although their mode of action as superantigens is well understood, little is known about their effects on airway epithelial cells. METHODS: To investigate this problem, primary nasal epithelial cells derived from normal and asthmatic subjects were stimulated with staphylococcal enterotoxin A and B (SEA and SEB) and secreted (supernatants) and cell-associated (cell lysates) IL-8, TNF-Ξ±, RANTES and eotaxin were determined by specific ELISAs. RESULTS: Non-toxic concentrations of SEA and SEB (0.01 ΞΌg/ml and 1.0 ΞΌg/ml) induced IL-8 secretion after 24 h of culture. Pre-treatment of the cells with IFN-Ξ³ (50 IU/ml) resulted in a further increase of IL-8 secretion. In cells from healthy donors pretreated with IFN-Ξ³, SEA at 1.0 ΞΌg/ml induced release of 1009 pg/ml IL-8 (733.0–1216 pg/ml, median (range)) while in cells from asthmatic donors the same treatment induced significantly higher IL-8 secretion – 1550 pg/ml (1168.0–2000.0 pg/ml p = 0.04). Normal cells pre-treated with IFN-Ξ³ and then cultured with SEB at 1.0 ΞΌg/ml released 904.6 pg/ml IL-8 (666.5–1169.0 pg/ml). Cells from asthmatics treated in the same way produced significantly higher amounts of IL-8 – 1665.0 pg/ml (1168.0–2000.0 pg/ml, p = 0.01). Blocking antibodies to MHC class II molecules added to cultures stimulated with SEA and SEB, reduced IL-8 secretion by about 40% in IFN-Ξ³ unstimulated cultures and 75% in IFN-Ξ³ stimulated cultures. No secretion of TNF-Ξ±, RANTES and eotaxin was noted. CONCLUSION: Staphylococcal enterotoxins may have a role in the pathogenesis of asthma

    Isolation and Characterization of Intestinal Epithelial Cells from Normal and SIV-Infected Rhesus Macaques

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    Impairment of intestinal epithelial barriers contributes to the progression of HIV/SIV infection and leads to generalized HIV-induced immune-cell activation during chronic infection. Rhesus macaques are the major animal model for studying HIV pathogenesis. However, detailed characterization of isolated rhesus epithelial cells (ECs) from intestinal tissues is not well defined. It is also not well documented whether isolated ECs had any other cell contaminants from intestinal tissues during the time of processing that might hamper interpretation of EC preparations or cultures. In this study, we identify and characterize ECs based on flow cytometry and immunohistochemistry methods using various enzymatic and mechanical isolation techniques to enrich ECs from intestinal tissues. This study shows that normal healthy ECs differentially express HLA-DR, CD23, CD27, CD90, CD95 and IL-10R markers. Early apoptosis and upregulation of ICAM-1 and HLA-DR in intestinal ECs are thought to be the key features in SIV mediated enteropathy. The data suggest that intestinal ECs might be playing an important role in mucosal immune responses by regulating the expression of different important regulatory and adhesion molecules and their function
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