723 research outputs found

    Extracorporeal circulation causes release of neutrophil gelatinase-associated lipocalin (NGAL).

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    Extracorporeal circulation (ECC) used during cardiac surgery causes activation of several inflammatory systems. These events are not fully understood but are responsible for complications during the immediate postoperative period. Neutrophil gelatinase-associated lipocalin (NGAL), a member of the expanding lipocalin family, has recently been described as an inflammatory protein. In this study, the release of NGAL into the circulation in 41 patients undergoing heart surgery with ECC was evaluated. A 4- to 5-fold elevation of the concentration of NGAL in plasma was observed during the immediate postoperative course with a rapid elimination during the first postoperative day. Four patients undergoing lung surgery (without ECC) were also studied. The plasma concentration of NGAL only increased with a factor of 1.1-2.2 over the operation. We conclude that NGAL is released into the circulation during heart surgery, probably as a result of the inflammatory activation of leukocytes initiated by the extracorporeal circulation

    Tool–chip thermal conductance coefficient and heat flux in machining : Theory, model and experiment

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    This study proposes a technique for determining a tool–chip thermal conductance coefficient and heat flux in machining. The technique is based on solving an inverse heat transfer problem (IHTP). Because the IHTP is ill-posed, a priori information is required for its effective solution. To derive this information, substantial qualitative and quantitative analysis of a mixed boundary value problem for the heat equation and an illustrative test case for IHTP are provided. It has been established that the averaged interfacial chip temperature is needed for an effective IHTP solution. Thermal imaging combined with a special experimental setup was used to determine chip temperature. It was also found that a function describing the heat flux time dependency belongs to a set of decreasing functions. Tool–chip thermal conductance coefficients were obtained for high-speed steel and cemented carbide tooling. On the microscale, this data was interpreted in terms of a conforming rough surface contact conductance model, where tool wear was found to govern variations in the thermal conductance coefficient

    Vaccination of pigs with attenuated Lawsonia intracellularis induced acute phase protein responses and primed cell-mediated immunity without reduction in bacterial shedding after challenge

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    AbstractBackgroundLawsonia intracellularis causes porcine proliferative enteropathy and is one of the most economically important diseases in modern pig production worldwide. The Enterisol® Ileitis vaccine have been shown to reduce clinical disease and to increase weight gain, however, while the natural infection with L. intracellularis can provide complete protection against re-infection, this has not been achieved by this vaccine. We therefore undertook a detailed characterization of immune responses to L. intracellularis infection in vaccinated pigs (VAC) compared to previously infected pigs (RE) in order to pinpoint immunological determinants of protection.ResultsThe VAC pigs shed L. intracellularis to the same extent as non-vaccinated pigs after challenge, however less L. intracellularis in ileum and lymph nodes was seen post mortem. In the RE group, challenge did not lead to L. intracellularis shedding and no challenge bacteria were found post mortem. In both VAC and RE the acute phase haptoglobin response was diminished and L. intracellularis specific IgG responses were delayed and reduced compared to non-vaccinated pigs. On the other hand L. intracellularis specific IFN-γ responses tended to develop faster in the VAC group compared to controls.ConclusionAlthough vaccinated and non-vaccinated pigs shed L. intracellularis at similar levels after challenge, a lower number of intestinal L. intracellularis was observed in the vaccinated pigs at post mortem inspection. This might be due to the observed faster CMI responses upon challenge in vaccinated pigs. Complete protection against infection without L. intracellularis shedding, however, was only seen after a previous infection resulting in IFN-γ production predominantly by CD8+ and CD4+ CD8+ cells. Improved protective vaccines against L. intracellularis should therefore target stimulation of these T cell subsets

    Designing real-time, continuous emotion annotation techniques for 360° VR videos

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    With the increasing availability of head-mounted displays (HMDs) that show immersive 360° VR content, it is important to understand to what extent these immersive experiences can evoke emotions. Typically to collect emotion ground truth labels, users rate videos through post-experience self-reports that are discrete in nature. However, post-stimuli self-reports are temporally imprecise, especially after watching 360° videos. In this work, we design six continuous emotion annotation techniques for the Oculus Rift HMD aimed at minimizing workload and distraction. Based on a co-design session with six experts, we contribute HaloLight and DotSize, two continuous annotation methods deemed unobtrusive and easy to understand. We discuss the next challenges for evaluating the usability of these techniques, and reliability of continuous annotations

    Investigations of solutions of Einstein's field equations close to lambda-Taub-NUT

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    We present investigations of a class of solutions of Einstein's field equations close to the family of lambda-Taub-NUT spacetimes. The studies are done using a numerical code introduced by the author elsewhere. One of the main technical complication is due to the S3-topology of the Cauchy surfaces. Complementing these numerical results with heuristic arguments, we are able to yield some first insights into the strong cosmic censorship issue and the conjectures by Belinskii, Khalatnikov, and Lifschitz in this class of spacetimes. In particular, the current investigations suggest that strong cosmic censorship holds in this class. We further identify open issues in our current approach and point to future research projects.Comment: 24 pages, 12 figures, uses psfrag and hyperref; replaced with published version, only minor corrections of typos and reference
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