3,366 research outputs found

    Anti-RhD immunoglobulin in the treatment of immune thrombocytopenia

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    Immune thrombocytopenia (ITP) is an acquired bleeding autoimmune disorder characterized by a markedly decreased blood platelet count. The disorder is variable, frequently having an acute onset of limited duration in children and a more chronic course in adults. A number of therapeutic agents have demonstrated efficacy in increasing the platelet counts in both children and adults. Anti-RhD immunoglobulin (anti-D) is one such agent, and has been successfully used in the setting of both acute and chronic immune thrombocytopenia. In this report we review the use of anti-D in the management of ITP. While the FDA-approved dose of 50 mg/kg has documented efficacy in increasing platelet counts in approximately 80% of children and 70% of adults, a higher dose of 75 μg/kg has been shown to result in a more rapid increase in platelet count without a greater reduction in hemoglobin. Anti-D is generally ineffective in patients who have failed splenectomy. Anti-RhD therapy has been shown capable of delaying splenectomy in adult patients, but does not significantly increase the total number of patients in whom the procedure can be avoided. Anti-D therapy appears to inhibit macrophage phagocytosis by a combination of both FcR blockade and inflammatory cytokine inhibition of platelet phagocytosis within the spleen. Anti-RhD treatment is associated with mild to moderate infusion toxicities. Rare life-threatening toxicities such as hemoglobinuria, acute renal failure and disseminated intravascular coagulation have been reported. Recommendations have been proposed to reduce the risk of these complications. Anti-D immunoglobulin can be an effective option for rapidly increasing platelet counts in patients with symptomatic ITP

    Virtual Power Consumption and Cooling Capacity Virtual Sensors for Rooftop Units

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    Implementation of advanced controls and diagnostic features in small commercial buildings typically requires real-time monitoring of the energy flows, such as the power consumption and cooling capacity of rooftop units. However, these measurements are expensive and therefore limit the application of these advanced features. In order to lower the measurement cost, virtual sensing technology for rooftop unit power consumption and cooling capacity are being developed. Power transmitters and thermocouples are installed on the rooftop units to train the virtual sensors. The idea is to recycle the power transmitters after training to save cost, and then the virtual sensors estimate hourly electrical consumption and cooling capacity using only low cost, non-invasive temperature measurements. In this paper, development and validation of the virtual sensors are presented. The virtual power consumption sensors are validated for 4 different rooftop units installed in the field, whereas the cooling capacity sensors are validated using 3 laboratory-tested rooftop units. The reliability of the sensors is also investigated by studying the uncertainty of the virtual sensor outputs under different operating conditions. A cost comparison between the virtual sensors and direct measurement methods is also conducted to evaluate the potential for widespread application of the virtual sensing technology

    Corrugated interfaces in multiphase core-annular flow

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    Microfluidic devices can be used to produce highly controlled and monodisperse double or multiple emulsions. The presence of inner drops inside a jet of the middle phase introduces deformations in the jet, which leads to breakup into monodisperse double emulsions. However, the ability to generate double emulsions can be compromised when the interfacial tension between the middle and outer phases is low, leading to flow with high capillary and Weber numbers. In this case, the interface between the fluids is initially deformed by the inner drops but the jet does not break into drops. Instead, the jet becomes highly corrugated, which prevents formation of controlled double emulsions. We show using numerical calculations that the corrugations are caused by the inner drops perturbing the interface and the perturbations are then advected by the flow into complex shapes

    Dichotomy for the Hausdorff dimension of the set of nonergodic directions

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    We consider billiards in a (1/2)-by-1 rectangle with a barrier midway along a vertical side. Let NE be the set of directions theta such that the flow in direction theta is not ergodic. We show that the Hausdorff dimension of the set NE is either 0 or 1/2, with the latter occurring if and only if the length of the barrier satisfies the condition of P'erez Marco, i.e. the sum of (loglog q_{k+1})/q_k is finite, where q_k is the the denominator of the kth convergent of the length of the barrier.Comment: 45 pages, 2 figures. Added motivational material requested by referee, in particular, a detailed sketch of the proof of main theorem was added to introduction. The notion of Z-expansion/Liouville direction was added as in order to abstract the proof of the Hausdorff dimension zero result

    Validation of a Fault-Modeling Equipped Vapor Compression System Model Using a Fault Detection and Diagnostics Evaluation Tool

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    A methodology for evaluating the performance of fault detection and diagnostics (FDD) tools for unitary air-conditioners has been developed (Yuill and Braun 2013). The methodology uses laboratory measurements of systems with and without faults to test FDD tools’ effectiveness. A gray box modeling method capable of modeling systems with faults was developed by Cheung and Braun (2013a and 2013b) to provide input data, as an alternative to using laboratory data that had been collected. The simulation method was validated by direct comparison with experimental data, but a comparison of FDD evaluation results provides a more direct and useful validation of the model for its intended purpose. Eight different systems have been modeled using Cheung and Braun’s method. Six FDD tools were evaluated using both experimental and modeled inputs under the same environmental and fault conditions. The fault conditions include non-standard charging, heat exchanger fouling, loss of compressor volumetric efficiency, liquid line restriction, and the presence of non-condensable gas in the refrigerant. The model’s performance is characterized by comparing its outputs from the evaluation – false alarm rates, misdiagnosis rates, missed detection rates, and rates of undiagnosed faults – with the results based upon experimental data. The model is found to be highly suitable for its purpose

    Evaluating Fault Detection and Diagnostics Tools with Simulations of Multiple Vapor Compression Systems

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    A methodology for evaluating the performance of fault detection and diagnostics (FDD) tools applied to unitary air conditioners has been developed by Yuill and Braun (2013). Data from faulted and unfaulted systems operating over a range of driving conditions are fed to the FDD tools, and the FDD responses are compared to the known operating conditions. The methodology originally relied upon experimental measurement data, but the amount of available data is limited, and evaluations can be far more meaningful if the operating conditions of the inputs can be controlled. Furthermore, a finite input set can be learned by an FDD algorithm, and the evaluation can be thereby gamed. To solve these problems, a large library of data from multiple systems under a wide range of conditions, with and without faults of varying magnitude, was generated with simulations from a novel gray-box modeling approach (Cheung and Braun 2013a, 2013b). The simulation outputs are used to train a neural network model, which is coupled to software that executes the evaluation method. The neural network model is much simpler than the semi-empirical approach, so it can produce evaluation inputs very quickly. This facilitates the evaluator generating semi-random conditions to provide a unique set of evaluation data that are sufficiently accurate and numerous to provide repeatable results. Some evaluation results from several FDD protocols are used to illustrate the success of this approach

    A novel anti-mycobacterial function of mitogen-activated protein kinase phosphatase-1

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    <p>Abstract</p> <p>Background</p> <p><it>Mycobacterium tuberculosis </it>(MTB) is a major cause of morbidity and mortality in the world. To combat against this pathogen, immune cells release cytokines including tumor necrosis factor-α (TNF-α), which is pivotal in the development of protective granulomas. Our previous results showed that Bacillus Calmette Guerin (BCG), a mycobacterium used as a model to investigate the immune response against MTB, stimulates the induction of TNF-α via mitogen-activated protein kinase (MAPK) in human blood monocytes. Since MAPK phosphatase-1 (MKP-1) is known to regulate MAPK activities, we examined whether MKP-1 plays a role in BCG-induced MAPK activation and cytokine expression.</p> <p>Results</p> <p>Primary human blood monocytes were treated with BCG and assayed for MKP-1 expression. Our results demonstrated that following exposure to BCG, there was an increase in the expression of MKP-1. Additionally, the induction of MKP-1 was regulated by p38 MAPK and extracellular signal-regulated kinase 1 and 2 (ERK1/2). Surprisingly, when MKP-1 expression was blocked by its specific siRNA, there was a significant decrease in the levels of phospho-MAPK (p38 MAPK and ERK1/2) and TNF-α inducible by BCG.</p> <p>Conclusions</p> <p>Since TNF-α is pivotal in granuloma formation, the results indicated an unexpected positive function of MKP-1 against mycobacterial infection as opposed to its usual phosphatase activity.</p
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