501 research outputs found

    Interventional suite and equipment management: cradle to grave

    Get PDF
    The acquisition process for interventional equipment and the care that this equipment receives constitute a comprehensive quality improvement program. This program strives to (a) achieve the production of good image quality that meets clinical needs, (b) reduce radiation doses to the patient and personnel to their lowest possible levels, and (c) provide overall good patient care at reduced cost. Interventional imaging equipment is only as effective and efficient as its supporting facility. The acquisition process of interventional equipment and the development of its environment demand a clinical project leader who can effectively coordinate the efforts of the many professionals who must communicate and work effectively on this type of project. The clinical project leader needs to understand (a) clinical needs of the end users, (b) how to justify the cost of the project, (c) the technical needs of the imaging and all associated equipment, (d) building and construction limitations, (e) how to effectively read construction drawings, and (f) how to negotiate and contract the imaging equipment from the appropriate vendor. After the initial commissioning of the equipment, it must not be forgotten. The capabilities designed into the imaging device can be properly utilized only by well-trained operators and staff who were initially properly trained and receive ongoing training concerning the latest clinical techniques throughout the equipment’s lifetime. A comprehensive, ongoing maintenance and repair program is paramount to reducing costly downtime of the imaging device. A planned periodic maintenance program can identify and eliminate problems with the imaging device before these problems negatively impact patient care

    Real-time flow simulation of indoor environments using lattice Boltzmann method

    Get PDF
    A novel lattice Boltzmann method (LBM) based 3D computational fluid dynamics (CFD) technique has been implemented on the graphics processing unit (GPU) for the purpose of simulating the indoor environment in real-time. We study the time evolution of the turbulent airflow and temperature inside a test chamber and in a simple model of a four-bed hospital room. The predicted results from LBM are compared with traditional CFD based large eddy simulations (LES). Reasonable agreement between LBM results and LES method is observed with significantly faster computational times

    Bacillus subtilis MreB Orthologs Self-Organize into Filamentous Structures underneath the Cell Membrane in a Heterologous Cell System

    Get PDF
    Actin-like bacterial cytoskeletal element MreB has been shown to be essential for the maintenance of rod cell shape in many bacteria. MreB forms rapidly remodelling helical filaments underneath the cell membrane in Bacillus subtilis and in other bacterial cells, and co-localizes with its two paralogs, Mbl and MreBH. We show that MreB localizes as dynamic bundles of filaments underneath the cell membrane in Drosophila S2 Schneider cells, which become highly stable when the ATPase motif in MreB is modified. In agreement with ATP-dependent filament formation, the depletion of ATP in the cells lead to rapid dissociation of MreB filaments. Extended induction of MreB resulted in the formation of membrane protrusions, showing that like actin, MreB can exert force against the cell membrane. Mbl also formed membrane associated filaments, while MreBH formed filaments within the cytosol. When co-expressed, MreB, Mbl and MreBH built up mixed filaments underneath the cell membrane. Membrane protein RodZ localized to endosomes in S2 cells, but localized to the cell membrane when co-expressed with Mbl, showing that bacterial MreB/Mbl structures can recruit a protein to the cell membrane. Thus, MreB paralogs form a self-organizing and dynamic filamentous scaffold underneath the membrane that is able to recruit other proteins to the cell surface

    Search for new physics with same-sign isolated dilepton events with jets and missing transverse energy

    Get PDF
    A search for new physics is performed in events with two same-sign isolated leptons, hadronic jets, and missing transverse energy in the final state. The analysis is based on a data sample corresponding to an integrated luminosity of 4.98 inverse femtobarns produced in pp collisions at a center-of-mass energy of 7 TeV collected by the CMS experiment at the LHC. This constitutes a factor of 140 increase in integrated luminosity over previously published results. The observed yields agree with the standard model predictions and thus no evidence for new physics is found. The observations are used to set upper limits on possible new physics contributions and to constrain supersymmetric models. To facilitate the interpretation of the data in a broader range of new physics scenarios, information on the event selection, detector response, and efficiencies is provided.Comment: Published in Physical Review Letter

    Compressed representation of a partially defined integer function over multiple arguments

    Get PDF
    In OLAP (OnLine Analitical Processing) data are analysed in an n-dimensional cube. The cube may be represented as a partially defined function over n arguments. Considering that often the function is not defined everywhere, we ask: is there a known way of representing the function or the points in which it is defined, in a more compact manner than the trivial one

    Performance of the CMS Cathode Strip Chambers with Cosmic Rays

    Get PDF
    The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

    TRAF6 Promotes Myogenic Differentiation via the TAK1/p38 Mitogen-Activated Protein Kinase and Akt Pathways

    Get PDF
    p38 mitogen-activated protein kinase (MAPK) is an essential kinase involved in myogenic differentiation. Although many substrates of p38 MAPK have been identified, little is known about its upstream activators during myogenic differentiation. TRAF6 is known to function in cytokine signaling during inflammatory responses. However, not much is known about its role in myogenic differentiation and muscle regeneration. We showed here that TRAF6 and its intrinsic ubiquitin E3 ligase activity are required for myogenic differentiation. In mouse myoblasts, knockdown of TRAF6 compromised the p38 MAPK and Akt pathways, while deliberate activation of either pathway rescued the differentiation defect caused by TRAF6 knockdown. TAK1 acted as a key signal transducer downstream of TRAF6 in myogenic differentiation. In vivo, knockdown of TRAF6 in mouse muscles compromised the injury-induced muscle regeneration without impairing macrophage infiltration and myoblast proliferation. Collectively, we demonstrated that TRAF6 promotes myogenic differentiation and muscle regeneration via the TAK1/p38 MAPK and Akt pathways

    Applications of the Lattice Boltzmann Method to Complex and Turbulent Flows

    Full text link
    Abstract. We brie y review the mathematics of the lattice Boltzmann equation, and show the direct numerical simulations of non-spherical particulate suspensions in uid ows and three-dimensional homogeneous isotropic turbulence ow in a periodic cubic box of the size 128 3. We compare the LBE simulation of the homo-geneous isotropic turbulence ow with the pseudo-spectral simulation. We observed that the lattice Boltzmann method is easy to implement on massively parallel com-puters and its computational speed scales linearly with the number of the CPUs.

    Effect of tube diameter and capillary number on platelet margination and near-wall dynamics

    Get PDF
    The effect of tube diameter DD and capillary number CaCa on platelet margination in blood flow at 37%\approx 37\% tube haematocrit is investigated. The system is modelled as three-dimensional suspension of deformable red blood cells and nearly rigid platelets using a combination of the lattice-Boltzmann, immersed boundary and finite element methods. Results show that margination is facilitated by a non-diffusive radial platelet transport. This effect is important near the edge of the cell-free layer, but it is only observed for Ca>0.2Ca > 0.2, when red blood cells are tank-treading rather than tumbling. It is also shown that platelet trapping in the cell-free layer is reversible for Ca0.2Ca \leq 0.2. Only for the smallest investigated tube (D=10μmD = 10 \mu\text{m}) margination is essentially independent of CaCa. Once platelets have reached the cell-free layer, they tend to slide rather than tumble. The tumbling rate is essentially independent of CaCa but increases with DD. Tumbling is suppressed by the strong confinement due to the relatively small cell-free layer thickness at 37%\approx 37\% tube haematocrit.Comment: 16 pages, 10 figure
    corecore