1,041 research outputs found

    Recruitment of dendritic cells and macrophages during T cell-mediated synovial inflammation

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    Adoptive transfer of adjuvant-induced arthritis was used in this study to examine local macrophages and dendritic cells (DCs) during T cell-mediated synovial inflammation. We studied the influx of CD11b+CD11c+ putative myeloid DCs and other non-lymphoid CD45+ cells into synovium-rich tissues (SRTs) of the affected hind paws in response to a pulse of autoreactive thoracic duct cells. Cells were prepared from the SRTs using a collagenase perfusion-digestion technique, thus allowing enumeration and phenotypic analysis by flow cytometry. Numbers of CD45+ cells increased during the first 6 days, with increases in CD45+MHC (major histocompatibility complex) II+ monocyte-like cells from as early as day 3 after transfer. In contrast, typical MHC II- monocytes, mainly of the CD4- subset, did not increase until 12 to 14 days after cell transfer, coinciding with the main influx of polymorphonuclear cells. By day 14, CD45+MHC IIhi cells constituted approximately half of all CD45+ cells in SRT. Most of the MHC IIhi cells expressed CD11c and CD11b and represented putative myeloid DCs, whereas only approximately 20% were CD163+ macrophages. Less than 5% of the MHC IIhi cells in inflamed SRT were CD11b-, setting a maximum for any influx of plasmacytoid DCs. Of the putative myeloid DCs, a third expressed CD4 and both the CD4+ and the CD4- subsets expressed the co-stimulatory molecule CD172a. Early accumulation of MHC IIhiCD11c+ monocyte-like cells during the early phase of T cell-mediated inflammation, relative to typical MHC II- blood monocytes, suggests that recruited monocytes differentiate rapidly toward the DC lineage at this stage in the disease process. However, it is possible also that the MHC IIhiCD11c+ cells originate from a specific subset of DC-like circulating mononuclear cells

    Novel Approaches towards Highly Selective Self-Powered Gas Sensors

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    The prevailing design approaches of semiconductor gas sensors struggle to overcome most of their current limitations such as poor selectivity, and high power consumption. Herein, a new sensing concept based on devices that are capable of detecting gases without the need of any external power sources required to activate interaction of gases with sensor or to generate the sensor read out signal. Based on the integration of complementary functionalities (namely; powering and sensing) in a singular nanostructure, self-sustained gas sensors will be demonstrated. Moreover, a rational methodology to design organic surface functionalization that provide high selectivity towards single gas species will also be discussed. Specifically, theoretical results, confirmed experimentally, indicate that precisely tuning of the sterical and electronic structure of sensor material/organic interfaces can lead to unprecedented selectivity values, comparable to those typical of bioselective processes. Finally, an integrated gas sensor that combine both the self-powering and selective detection strategies in one single device will also be presented. © 2015 Published by Elsevier Ltd.Peer ReviewedPostprint (published version

    A note on the Near Flat Limit for strings in the Maldacena-Nunez background

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    Recently Maldacena and Swanson suggested a new limit of string theory on the AdS5×S5AdS_5\times S^5 background, the so called near flat space limit. The resulting reduced theory interpolates between the pp-wave limit and giant magnon type string solutions. It was shown that the reduced model possess many features of the original theory. On the other hand, theories with less supersymmetry are of great importance for the string/gauge theory correspondence. In this paper we study the near flat limit reduction of string theory on the Maldacena-Nunez background, which is dual to N=1\N=1 Yang-Mills theory. The reduced model interpolates between the pp-wave limit and a certain magnon type subsector of the theory. The similarity of the structures of the reduced model obtained here and that by Maldacena and Swanson indicates the possibility of existence of integrable subsectors of strings on the Maldacena-Nunez background.Comment: 1+23 pages, introduction improved and clarifying comments added, references added, results remain unchange

    Machine-learning potentials for nanoscale simulations of deformation and fracture: example of TiB2_2 ceramic

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    Machine-learning interatomic potentials (MLIPs) offer a powerful avenue for simulations beyond length and timescales of ab initio methods. Their development for investigation of mechanical properties and fracture, however, is far from trivial since extended defects -- governing plasticity and crack nucleation in most materials -- are too large to be included in the training set. Using TiB2_2 as a model ceramic material, we propose a strategy for fitting MLIPs suitable to simulate mechanical response of monocrystals until fracture. Our MLIP accurately reproduces ab initio stresses and failure mechanisms during room-temperature uniaxial tensile deformation of TiB2_2 at the atomic scale (≈103\approx{10}^3 atoms). More realistic tensile tests (low strain rate, Poisson's contraction) at the nanoscale (≈104\approx{10}^4--106^6 atoms) require MLIP up-fitting, i.e. learning from additional ab initio configurations. Consequently, we elucidate trends in theoretical strength, toughness, and crack initiation patterns under different loading directions. To identify useful environments for further up-fitting, i.e., making the MLIP applicable to a wider spectrum of simulations, we asses transferability to other deformation conditions and phases not explicitly trained on

    The emotional well-being of young people: a review of the literature.

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    Suicide is increasingly described by governments and policy-makers as a global public health problem. Between 1950 and 1995 global suicide rates have increased by 60%. In recent years concerns have been expressed in Scotland and the UK about rising suicide rates amongst children and young people and the accumulation of increasing evidence that the adoption of negative coping strategies is contributing to rising levels of deliberate self harm (DSH).This literature review was in part used and incorporated into chapter two of the final report, The emotional wellbeing of young people: final report of phase one of a 'Choose Life' research project in Aberdeenshire (March 2004-March 2007), which can be found at http://hdl.handle.net/10059/439
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