120 research outputs found

    Search for Charged Higgs Bosons in e+e- Collisions at \sqrt{s} = 189 GeV

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    A search for pair-produced charged Higgs bosons is performed with the L3 detector at LEP using data collected at a centre-of-mass energy of 188.6 GeV, corresponding to an integrated luminosity of 176.4 pb^-1. Higgs decays into a charm and a strange quark or into a tau lepton and its associated neutrino are considered. The observed events are consistent with the expectations from Standard Model background processes. A lower limit of 65.5 GeV on the charged Higgs mass is derived at 95 % confidence level, independent of the decay branching ratio Br(H^{+/-} -> tau nu)

    Haemodynamics and flow modification stents for peripheral arterial disease:a review

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    Endovascular stents are widely used for the treatment of peripheral arterial disease (PAD). However, the development of in-stent restenosis and downstream PAD progression remain a challenge. Stent revascularisation of PAD causes arterial trauma and introduces abnormal haemodynamics, which initiate complicated biological processes detrimental to the arterial wall. The interaction between stent struts and arterial cells in contact, and the blood flow field created in a stented region, are highly affected by stent design. Spiral flow is known as a normal physiologic characteristic of arterial circulation and is believed to prevent the development of flow disturbances. This secondary flow motion is lost in atheromatous disease and its re-introduction after endovascular treatment of PAD has been suggested as a method to induce stabilised and coherent haemodynamics. Stent designs able to generate spiral flow may support endothelial function and therefore increase patency rates. This review is focused on secondary flow phenomena in arteries and the development of flow modification stent technologies for the treatment of PAD

    Synthesis of 2-azidoethyl α-d-mannopyranoside orthogonally protected and selective deprotections

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    4 páginas, 1 figura, 2 esquemas.We present the synthesis of a fully orthogonally protected mannosyl glycoside 1 and the corresponding methods for selective deprotections. Mannosyl glycoside 1 contains a functionalized linker at the anomeric position to allow for the attachment of carbohydrate units to scaffolds in order to prepare carbohydrate multivalent systems.We would like to thank FIS (PI030093), for financial supportPeer reviewe

    Developing interdisciplinary science for integrated catchment management : the UK lowland catchment research (LOCAR) programme

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    Across the European Union, the Water Framework Directive is a major driver for change in river basin management. However, its focus on integrated management and, in particular, on ecological quality raises major scientific and technical questions. In the UK, the focus of experimental hydrology has been on the uplands, and at small catchment scale (< 10 km2), whereas major management pressures lie in the lowlands, and for catchment management units of about 300-400 km2. Particular problems arise for permeable lowland catchments: the scientific understanding of the major UK aquifers (the Chalk and the Triassic Sandstone) is poor, and tools for the integrated modelling of surface water-groundwater interactions are limited. In response to these factors, the LOwland CAtchment Research programme (LOCAR) was conceived. A major objective of the programme is to develop new interdisciplinary science and improved modelling tools to meet the challenges of integrated catchment management. The paper describes the research programme and addresses the issues raised in designing and implementing a major interdisciplinary research initiative
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