135 research outputs found

    Chaos and Quantum Chaos in Cosmological Models

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    Spatially homogeneous cosmological models reduce to Hamiltonian systems in a low dimensional Minkowskian space moving on the total energy shell H=0H=0. Close to the initial singularity some models (those of Bianchi type VIII and IX) can be reduced further, in a certain approximation, to a non-compact triangular billiard on a 2-dimensional space of constant negative curvature with a separately conserved positive kinetic energy. This type of billiard has long been known as a prototype chaotic dynamical system. These facts are reviewed here together with some recent results on the energy level statistics of the quantized billiard and with direct explicit semi-classical solutions of the Hamiltonian cosmological model to which the billiard is an approximation. In the case of Bianchi type IX models the latter solutions correspond to the special boundary conditions of a `no-boundary state' as proposed by Hartle and Hawking and of a `wormhole' state.Comment: 23 pages, Late

    Reduced Inflammatory Threshold Indicates Skin Barrier Defect in Transglutaminase 3 Knockout Mice

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    Recently a transglutaminase 3 knockout (TGM3/KO) mouse was generated that showed impaired hair development, but no gross defects in the epidermal barrier, although increased fragility of isolated corneocytes was demonstrated. Here we investigated the functionality of skin barrier in vivo by percutaneous sensitization to fluorescein-isothiocyanate (FITC) in TGM3/KO (n=64) and C57BL/6 WT mice (n=36). Cutaneous inflammation was evaluated by mouse ear swelling test (MEST), histology, serum IgE levels, and by flow-cytometry from draining lymph nodes. Inflammation induced significant MEST difference (P<0.0001) was detected between KO and WT mice and was supported also by histopathology. A significant increase of CD4+ CD25+ activated T-cells (P<0.01) and elevated serum IgE levels (P<0.05) in KO mice indicated more the development of FITC sensibilization than an irritative reaction. P. acnes induced intracutaneous inflammation showed no difference (P=0.2254) between the reactivity of WT and KO immune system. As in vivo tracer, FITC penetration from skin surface followed by two-photon microscopy demonstrated a more invasive percutaneous penetration in KO mice. The clinically uninvolved skin in TGM3/KO mice showed impaired barrier function and higher susceptibility to FITC sensitization indicating that TGM3 has a significant contribution to the functionally intact cutaneous barrier.Journal of Investigative Dermatology accepted article preview online, 24 July 2013. doi:10.1038/jid.2013.307

    Nanobio Silver: Its Interactions with Peptides and Bacteria, and Its Uses in Medicine

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    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    Transglutaminases in autoimmune and inherited skin diseases: The phenomena of epitope spreading and functional compensation

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    Transglutaminases (TGs) are structurally and functionally related enzymes that modify the post-translational structure and activity of proteins or peptides, and thus are able to turn on or switch off their function. Depending on location and activities, TGs are able to modify the signalling, the function and the fate of cells and extracellular connective tissues. Besides mouse models, human diseases enable us to appreciate the function of various TGs. In this study, skin diseases induced by genetic damages or autoimmune targeting of these enzymes will be discussed. TG1, TG3 and TG5 contribute to the cutaneous barrier and thus to the integrity and function of epidermis. TGM1 mutations related to autosomal recessive ichthyosis subtypes, TGM5 mutations to a mild epidermolysis bullosa phenotype and as novelty TGM3 mutation to uncombable hair syndrome will be discussed. Autoimmunity to TG2, TG3 and TG6 may develop in a few of those genetically determined individuals who lost tolerance to gluten, and manifest as coeliac disease, dermatitis herpetiformis or gluten-dependent neurological symptoms, respectively. These gluten responder diseases commonly occur in combination. In autoimmune diseases, the epitope spreading is remarkable, while in some inherited pathologies, a unique compensation of the lost enzyme function is noted
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