8,773 research outputs found

    Purinergic receptor mediated calcium signalling in urothelial cells

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    Non-neuronal ATP released from the urothelium in response to bladder stretch is a key modulator of bladder mechanosensation. Whilst non-neuronal ATP acts on the underlying bladder afferent nerves to facilitate sensation, there is also the potential for ATP to act in an autocrine manner, modulating urothelial cell function. The aim of this study was to systematically characterise the functional response of primary mouse urothelial cells (PMUCs) to ATP. PMUCs isolated from male mice (14-16 weeks) were used for live-cell fluorescent calcium imaging and qRT-PCR to determine the expression profile of P2X and P2Y receptors. The majority of PMUCs (74-92%) responded to ATP (1 μM-1 mM), as indicted by an increase in intracellular calcium (iCa2+). PMUCs exhibited dose-dependent responses to ATP (10 nM-1 mM) in both calcium containing (2 mM, EC50 = 3.49 ± 0.77 μM) or calcium free (0 mM, EC50 = 9.5 ± 1.5 μM) buffers. However, maximum iCa2+ responses to ATP were significantly attenuated upon repetitive applications in calcium containing but not in calcium free buffer. qRT-PCR revealed expression of P2X1-6, and P2Y1-2, P2Y4, P2Y6, P2Y11-14, but not P2X7 in PMUCs. These findings suggest the major component of ATP induced increases in iCa2+ are mediated via the liberation of calcium from intracellular stores, implicating functional P2Y receptors that are ubiquitously expressed on PMUCs.Russell Chess-Williams, Donna J. Sellers, Stuart M. Brierley, David Grundy, Luke Grund

    Advancing knowledge for haemato-oncology nursing practice

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    Nurses working in haemato-oncology require specialised knowledge and yet, formal education programmes and textbooks devoted to the speciality are limited. In advancing knowledge for haemato-oncology nursing practice this project endeavours to develop, synthesise, organise and disseminate available evidence making it more accessible to practising nurses. The project consists of two inter-related parts: reflection on, and critique of, the development and editing of the second edition of a nursing textbook and a Delphi study of research priorities in haemato-oncology nursing included as a chapter of the textbook. In aiming to expand and advance the knowledge base for nurses working in haematooncology the concept of knowledge, ways of acquiring knowledge and types of nursing knowledge are explored and critically analysed. A textbook is mainly a source of empirical knowledge but ways of encouraging the development of other forms of relevant knowledge are discussed in relation to the format of the textbook. Critical reflection on the development of the textbook is also undertaken to detennine usefulness and value. Development of the first edition of the textbook and analysis of existing literature in haemato-oncology nursing highlighted the paucity of research informing the speciality. This provided the incentive to undertake the Delphi study. Round 1 generated a wide range of research topics, subsequently used to develop the questionnaire for round 2. Round 2 results demonstrated close clustering and little discrimination between research topics. Round 3 was therefore undertaken to increase the reliability and credibility of results and further discriminate between research priorities. Results from rounds 2 and 3 were remarkably consistent with several strong research themes emerging. These themes provide the foundations for the development of a research strategy with the potential to further advance knowledge for haemato-oncology nursing practice

    Color, composition, and thermal environment of Kuiper Belt object (486958) Arrokoth

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    The outer Solar System object (486958) Arrokoth (provisional designation 2014 MU₆₉) has been largely undisturbed since its formation. We study its surface composition using data collected by the New Horizons spacecraft. Methanol ice is present along with organic material, which may have formed through irradiation of simple molecules. H₂O ice is not detected. This composition indicates hydrogenation of CO-rich ice and/or energetic processing of CH₄+H₂O ices in the cold, outer edge of the early Solar System. There are only small regional variations in color and spectra across the surface, suggesting Arrokoth formed from a homogeneous or well-mixed reservoir of solids. Microwave thermal emission from the winter night side is consistent with a mean brightness temperature of 29 ± 5 K

    Growth rate effects in soft CoFe films

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    We report on growth rate effects in sputter-deposited CoFe films prepared using high target utilization sputtering technology (HiTUS). We find that the grain structure of these polycrystalline films is closely related to the growth rate. By changing the growth rate, samples were prepared with different grain structure, which in turn had the effect of changing the magnetic properties of the films. We demonstrate control of the coercivity, which varied by a factor of more than ten. This was achieved via grain size control in CoFe films of thickness 20 nm. Furthermore, by employing a two-step sputtering process, in which two extreme growth rates are used sequentially, we were able to tune the saturation magnetization

    Novel sputtering-technology for grain-size control

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    In this paper, we present a description of a novel high-rate plasma sputtering system that allows the control of grain size in sputtered films. Additionally, the system has the advantage of a better utilization of the target material (around 80% to 90%) by eliminating the race track at the target as in conventional plasma magnetron sputtering systems. The potential and capabilities of this novel plasma sputtering device are demonstrated in this paper by the deposition of a number of different Cr thin films suitable for underlayers in thin-film media and for which we have performed a systematic X-ray and TEM analysis to determine the grain-size histograms, mean grain diameters, and their relationship to the sputtering processes

    Transition state theory and the dynamics of hard disks

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    The dynamics of two and five disk systems confined in a square has been studied using molecular dynamics simulations and compared with the predictions of transition state theory. We determine the partition functions Z and Z^\ddagger of transition state theory using a procedure first used by Salsburg and Wood for the pressure. Our simulations show this procedure and transition state theory are in excellent agreement with the simulations. A generalization of the transition state theory to the case of a large number of disks N is made and shown to be in full agreement with simulations of disks moving in a narrow channel. The same procedure for hard spheres in three dimensions leads to the Vogel-Fulcher-Tammann formula for their alpha relaxation time.Comment: 1 new author, new simulations and figures, less speculation. Now 6 pages, 6 figures, 1 animation. Animation may be viewed at http://www.theory.physics.manchester.ac.uk/~godfrey/supplement/activated_dynamics2.htm

    Plant cell walls: impact on nutrient bioaccessibility and digestibility

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    Cell walls are important structural components of plants, affecting both the bioaccessibility and subsequent digestibility of the nutrients that plant-based foods contain. These supramolecular structures are composed of complex heterogeneous networks primarily consisting of cellulose, and hemicellulosic and pectic polysaccharides. The composition and organization of these different polysaccharides vary depending on the type of plant tissue, imparting them with specific physicochemical properties. These properties dictate how the cell walls behave in the human gastrointestinal tract, and how amenable they are to digestion, thereby modulating nutrient release from the plant tissue. This short narrative review presents an overview of our current knowledge on cell walls and how they impact nutrient bioaccessibility and digestibility. Some of the most relevant methods currently used to characterize the food matrix and the cell walls are also described

    Recent Developments in Federal Appellate Practice and Procedure

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    This article summarizes significant developments in federal appellate practice and procedure in three areas: (1) amendments to the Federal Rules of Appellate Procedure, (2) case law from the United States Supreme Court and the circuit courts of appeals, and (3) articles worth reading
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