15,742 research outputs found

    Canine platelets express functional Toll-like receptor-4: lipopolysaccharide-triggered platelet activation is dependent on adenosine diphosphate and thromboxane A2 in dogs.

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    BackgroundFunctional Toll-like receptor 4 (TLR4) has been characterized in human and murine platelets indicating that platelets play a role in inflammation and hemostasis during sepsis. It is unclear whether canine platelets could express functional TLR4 by responding to its ligand, lipopolysaccharide (LPS). We sought to determine if dogs express functional TLR4 and if LPS-induced platelet activation requires co-stimulation with ADP or thromboxane A2 (TxA2). Canine platelets were unstimulated (resting) or activated with thrombin or ADP prior to flow cytometric or microscopic analyses for TLR4 expression. We treated resting or ADP-primed platelets with LPS in the absence or presence of acetylsalicylic acid (ASA) and inhibited TLR4 with function blocking antibody or LPS from Rhodobacter sphaeroides (LPS-RS).ResultsWe discovered that dog platelets have variable TLR4 expression, which was upregulated following thrombin or ADP activation. LPS augmented P-selectin expression and thromboxane B2 secretion in ADP-primed platelets via TLR4. Inhibition of cyclooxygenase by ASA attenuated LPS-mediated P-selectin expression demonstrating that TLR4 signaling in platelets is partially dependent on TxA2 pathway.ConclusionExpression of functional TLR4 on canine platelets may contribute to hypercoagulability in clinical septic dogs. Cyclooxygenase and TxA2 pathways in TLR4-mediated platelet activation may present novel therapeutic targets in dogs with sepsis

    Photoelectrocatalytic oxidation of rhodamine B in aqueous solution using Ti/TiO?mesh photoelectrodes

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    Author name used in this publication: X. Z. LiAuthor name used in this publication: F. B. LiAuthor name used in this publication: C. L. Mak2001-2002 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe

    Magnetic coupling properties of rare-earth metals (Gd, Nd) doped ZnO: first-principles calculations

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    The electronic structure and magnetic coupling properties of rare-earth metals (Gd, Nd) doped ZnO have been investigated using first-principles methods. We show that the magnetic coupling between Gd or Nd ions in the nearest neighbor sites is ferromagnetic. The stability of the ferromagnetic coupling between Gd ions can be enhanced by appropriate electron doping into ZnO:Gd system and the room-temperature ferromagnetism can be achieved. However, for ZnO:Nd system, the ferromagnetism between Nd ions can be enhanced by appropriate holes doping into the sample. The room-temperature ferromagnetism can also be achieved in the \emph{n}-conducting ZnO:Nd sample. Our calculated results are in good agreement with the conclusions of the recent experiments. The effect of native defects (VZn_{\rm{Zn}}, VO_{\rm{O}}) on the ferromagnetism is also discussed.Comment: 5 pages, 5 figure

    Statistical atlas based registration and planning for ablating bone tumors in minimally invasive interventions

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    Bone tumor ablation has been a viable treatment in a minimally invasive way compared with surgical resections. In this paper, two key challenges in the computer-Assisted bone tumor ablation have been addressed: 1) establishing the spatial transformation of patient's tumor with respect to a global map of the patient using a minimum number of intra-operative images and 2) optimal treatment planning for large tumors. Statistical atlas is employed to construct the global reference map. The atlas is deformably registered to a pair of intra-operative fluoroscopy images, constructing a patient-specific model, in order to reduce the radiation exposure to the sensitive patients such as pregnant and infants. The optimal treatment planning system incorporates clinical constraints on ablations and trajectories using a multiple objective optimization, which obtains optimal trajectory planning and ablation coverage using integer programming. The proposed system is presented and validated by experiments. © 2012 IEEE.published_or_final_versio

    Self-focused acoustic ejectors for viscous liquids

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    Author name used in this publication: K. W. kwok2009-2010 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Inclusion of interbar currents in a network-field coupled time-stepping finite-element model of skewed-rotor induction motors

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    Author name used in this publication: S. L. HoAuthor name used in this publication: W. N. FuVersion of RecordPublishe

    Packing While Traveling: Mixed Integer Programming for a Class of Nonlinear Knapsack Problems

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    Packing and vehicle routing problems play an important role in the area of supply chain management. In this paper, we introduce a non-linear knapsack problem that occurs when packing items along a fixed route and taking into account travel time. We investigate constrained and unconstrained versions of the problem and show that both are NP-hard. In order to solve the problems, we provide a pre-processing scheme as well as exact and approximate mixed integer programming (MIP) solutions. Our experimental results show the effectiveness of the MIP solutions and in particular point out that the approximate MIP approach often leads to near optimal results within far less computation time than the exact approach
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