172 research outputs found

    Tannaka-Krein duality for Hopf algebroids

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    We develop the Tannaka-Krein duality for monoidal functors with target in the categories of bimodules over a ring. The \coend of such a functor turns out to be a Hopf algebroid over this ring. Using the result of a previous paper we characterize a small abelian, locally finite rigid monoidal category as the category of rigid comodules over a transitive Hopf algebroid.Comment: 25 pages, final version, to appear in Israel Journal of Mathematic

    Biodentine Reduces Tumor Necrosis Factor Alpha-induced TRPA1 Expression in Odontoblastlike Cells

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    International audienceIntroduction: The transient receptor potential (TRP) ion channels have emerged as important cellular sensors in both neuronal and non-neuronal cells, with TRPA1 playing a central role in nociception and neurogenic inflammation. The functionality of TRP channels has been shown to be modulated by inflammatory cytokines. The aim of this study was to investigate the effect of inflammation on odontoblast TRPA1 expression and to determine the effect of Biodentine (Septodent, Paris, France) on inflammatory-induced TRPA1 expression. Methods: Immunohistochemistry was used to study TRPA1 expression in pulp tissue from healthy and carious human teeth. Pulp cells were differentiated to odontoblastlike cells in the presence of 2 mmol/L beta-glycerophosphate, and these cells were used in quantitative polymerase chain reaction, Western blotting, calcium imaging, and patch clamp studies. Results: Immunofluorescent staining revealed. TRPA1 expression in odontoblast cell bodies and odontoblast processes, which was more intense in carious versus healthy teeth. TRPA1 gene expression was induced in cultured odontoblastlike cells by tumor necrosis factor alpha, and this expression was significantly reduced in the presence of Biodentine. The functionality of the TRPA1 channel was shown by calcium microfluorimetry and patch clamp recording, and our results showed a significant reduction in tumor necrosis factor alpha induced TRPA1 responses after Biodentine treatment. Conclusions: In conclusion, this study showed TRPA1 to be modulated by caries-induced inflammation and that Biodentine reduced TRPA1 expression and functional responses

    The collisional depolarization of OH(A 2Σ+) and NO(A 2Σ+) with Kr

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    Quantum beat spectroscopy has been used to measure rate coefficients at 300 K for collisional depolarization for NO(A 2Σ+) and OH(A 2Σ+) with krypton. Elastic depolarization rate coefficients have also been determined for OH(A) + Kr, and shown to make a much more significant contribution to the total depolarization rate than for NO(A) + Kr. While the experimental data for NO(A) + Kr are in excellent agreement with single surface quasiclassical trajectory (QCT) calculations carried out on the upper 2A ′ potential energy surface, the equivalent QCT and quantum mechanical calculations cannot account for the experimental results for OH(A) + Kr collisions, particularly at low N. This disagreement is due to the presence of competing electronic quenching at low N, which requires a multi-surface, non-adiabatic treatment. Somewhat improved agreement with experiment is obtained by means of trajectory surface hopping calculations that include non-adiabatic coupling between the ground 1A ′ and excited 2A ′ states of OH(X/A) + Kr, although the theoretical depolarization cross sections still significantly overestimate those obtained experimentally

    Bridging the gap: an exploration of the use and impact of positive action in the UK

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    Despite laws in Britain permitting limited positive action initiatives to combat disadvantage faced by minority groups in employment since the mid-1970s, the subject has notoriously been a neglected and highly controversial area in the UK. Notwithstanding the potential provided by sections 158 and 159 of the Equality Act 2010, it still appears that organisations prefer to steer clear of this opportunity to address disadvantage suffered by protected groups. Whilst there is a body of work considering the theoretical importance of positive action in the UK, there is a lack of empirical exploration of the practical implications of these provisions. This paper will provide a brief overview of the theoretical context and current positive action legislative provisions within the UK. In light of this context, the early findings of a small-scale qualitative study carried out by the authors will be discussed looking at the experiences of a purposive sample of public and private employers in relation to the positive action provisions of the Equality Act 2010. Early research findings suggest that whilst there was a clear willingness and openness by employers to use of outreach measures in order to redress disadvantage, there was evident wariness regarding a move towards preferential treatment as expounded by section 159. Whilst respondents appeared to appreciate the business case for and utility of the positive action measures under section 158, there was far less enthusiasm for more direct preferential treatment, with many respondents raising serious concerns regarding this. These concerns often reflected a highly sensitive risk-based approach towards any action that could expose their organisation to the possibility of “reverse discrimination”

    Prostate cancer cells modulate osteoblast mineralisation and osteoclast differentiation through Id-1

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    Background: Id-1 is overexpressed in and correlated with metastatic potential of prostate cancer. The role of Id-1 in this metastatic process was further analysed. Methods: Conditioned media from prostate cancer cells, expressing various levels of Id-1, were used to stimulate pre-osteoclast differentiation and osteoblast mineralisation. Downstream effectors of Id-1 were identified. Expressions of Id-1 and its downstream effectors in prostate cancers were studied using immunohistochemistry in a prostate cancer patient cohort (N110). Results: We found that conditioned media from LNCaP prostate cancer cells overexpressing Id-1 had a higher ability to drive osteoclast differentiation and a lower ability to stimulate osteoblast mineralisation than control, whereas conditioned media from PC3 prostate cancer cells with Id-1 knockdown were less able to stimulate osteoclast differentiation. Id-1 was found to negatively regulate TNF-Β and this correlation was confirmed in human prostate cancer specimens (P0.03). Furthermore, addition of recombinant TNF-Β to LNCaP Id-1 cell-derived media blocked the effect of Id-1 overexpression on osteoblast mineralisation. Conclusion: In prostate cancer cells, the ability of Id-1 to modulate bone cell differentiation favouring metastatic bone disease is partially mediated by TNF-Β, and Id-1 could be a potential therapeutic target for prostate cancer to bone metastasis. © 2010 Cancer Research UK. All rights reserved.link_to_OA_fulltex

    Microneedles: A New Frontier in Nanomedicine Delivery

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    This review aims to concisely chart the development of two individual research fields, namely nanomedicines, with specific emphasis on nanoparticles (NP) and microparticles (MP), and microneedle (MN) technologies, which have, in the recent past, been exploited in combinatorial approaches for the efficient delivery of a variety of medicinal agents across the skin. This is an emerging and exciting area of pharmaceutical sciences research within the remit of transdermal drug delivery and as such will undoubtedly continue to grow with the emergence of new formulation and fabrication methodologies for particles and MN. Firstly, the fundamental aspects of skin architecture and structure are outlined, with particular reference to their influence on NP and MP penetration. Following on from this, a variety of different particles are described, as are the diverse range of MN modalities currently under development. The review concludes by highlighting some of the novel delivery systems which have been described in the literature exploiting these two approaches and directs the reader towards emerging uses for nanomedicines in combination with MN
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