450 research outputs found

    The Cummins advanced turbocompound diesel engine evaluation

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    An advanced turbocompound diesel engine program was initiated to improve the tank mileage of the turbocompound engine by 5% over the vehicle test engines. Engine improvements could be realized by increasing the available energy of the exhaust gas at the turbine inlet, incorporating gas turbine techniques into improving the turbomachinery efficiencies, and through refined engine system optimization. The individual and cumulative performance gains achieved with the advanced turbocompound engine improvements are presented

    Detection of mechanical resonance of a single-electron transistor by direct current

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    We have suspended an Al based single-electron transistor whose island can resonate freely between the source and drain leads forming the clamps. In addition to the regular side gate, a bottom gate with a larger capacitance to the SET island is placed underneath to increase the SET coupling to mechanical motion. The device can be considered as a doubly clamped Al beam that can transduce mechanical vibrations into variations of the SET current. Our simulations based on the orthodox model, with the SET parameters estimated from the experiment, reproduce the observed transport characteristics in detail.Comment: 4 pages, 3 figure

    Cardiopulmonary resuscitation outcomes of dogs and cats at a veterinary teaching hospital before and after publication of the RECOVER guidelines.

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    OBJECTIVES To describe and compare cardiopulmonary resuscitation outcomes at a Swiss veterinary teaching hospital before and after publication of the Reassessment Campaign on Veterinary Resuscitation guidelines. MATERIALS AND METHODS Between 2018 and 2020, hospital staff underwent various types of yearly Reassessment Campaign on Veterinary Resuscitation-based cardiopulmonary resuscitation trainings. Canine and feline cardiopulmonary resuscitation events during that period (post-Reassessment Campaign on Veterinary Resuscitation) and between 2010 and 2012 (pre-Reassessment Campaign on Veterinary Resuscitation) were identified and animal, arrest and outcome variables recorded retrospectively. Factors associated with return of spontaneous circulation were determined using multi-variable logistic regression, odds ratios (95% confidence interval) generated, and significance set at P < 0.05. RESULTS Eighty-one animals were included in the pre-Reassessment Campaign on Veterinary Resuscitation group and 190 in the post-Reassessment Campaign on Veterinary Resuscitation group. Twenty-three percent in the pre-Reassessment Campaign on Veterinary Resuscitation group and 28% in the post-Reassessment Campaign on Veterinary Resuscitation group achieved return of spontaneous circulation and 1% and 4% survived to hospital discharge, respectively. Patients undergoing anaesthesia [odds ratio 4.26 (1.76 to 10.27)], elective [odds ratio 5.16 (1.06 to 25.02)] or emergent surgery [odds ratio 3.09 (1.20 to 8.00)], or experiencing cardiopulmonary arrest (CPA) due to arrhythmias [odds ratio 4.31 (1.44 to 12.93)] had higher odds of return of spontaneous circulation, while those with unknown cause of CPA [odds ratio 0.25 (0.08 to 0.78)] had lower odds. Undergoing cardiopulmonary resuscitation in the post-Reassessment Campaign on Veterinary Resuscitation period was not statistically significantly associated with return of spontaneous circulation [odds ratio 1.38 (0.68 to 2.79)]. CLINICAL SIGNIFICANCE Unchanged odds of return of spontaneous circulation in the post-Reassessment Campaign on Veterinary Resuscitation period could suggest that once-yearly cardiopulmonary resuscitation training is insufficient, effects of animal and tertiary referral hospital variables confounded results, guideline benefit is limited, or that compliance during clinical cardiopulmonary resuscitation efforts is too poor for guideline recommendations to have a positive impact. More extensive cardiopulmonary resuscitation training protocols should be established, and the compliance with and outcome benefits of a Reassessment Campaign on Veterinary Resuscitation-based cardiopulmonary resuscitation approach re-evaluated prospectively

    Damping in high-frequency metallic nanomechanical resonators

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    We have studied damping in polycrystalline Al nanomechanical resonators by measuring the temperature dependence of their resonance frequency and quality factor over a temperature range of 0.1 - 4 K. Two regimes are clearly distinguished with a crossover temperature of 1 K. Below 1 K we observe a logarithmic temperature dependence of the frequency and linear dependence of damping that cannot be explained by the existing standard models. We attribute these phenomena to the effect of the two-level systems characterized by the unexpectedly long (at least two orders of magnitude longer) relaxation times and discuss possible microscopic models for such systems. We conclude that the dynamics of the two-level systems is dominated by their interaction with one-dimensional phonon modes of the resonators.Comment: 5 pages, 3 figure

    A study of turbofan-engine compressor noise suppression techniques

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    Nacelle design for turbofan engine compressor noise suppression on Douglas DC-8 aircraf

    Coherent superconducting quantum pump

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    We demonstrate non-adiabatic charge pumping utilizing a sequence of coherent oscillations between a superconducting island and two reservoirs. Our method, based on pulsed quantum state manipulations, allows to speedup charge pumping to a rate which is limited by the coupling between the island and the reservoirs given by the Josephson energy. Our experimental and theoretical studies also demonstrate that relaxation can be employed to reset the pump and avoid accumulation of errors due to non-ideal control pulses.Comment: 4 pages, 3 figure

    A Systematic Comparison of 18F-C-SNAT to Established Radiotracer Imaging Agents for the Detection of Tumor Response to Treatment

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    PURPOSE: An early readout of tumor response to therapy through measurement of drug or radiation-induced cell death may provide important prognostic indications and improved patient management. It has been shown that the uptake of (18)F-C-SNAT can be used to detect early response to therapy in tumors by positron emission tomography (PET) via a mechanism of caspase-3-triggered nanoaggregation. EXPERIMENTAL DESIGN: Here, we compared the preclinical utility of (18)F-C-SNAT for the detection of drug-induced cell death to clinically evaluated radiotracers, (18)F-FDG, (99m)Tc-Annexin V, and (18)F-ML-10 in tumor cells in culture, and in tumor-bearing mice in vivo. RESULTS: In drug-treated lymphoma cells, (18)F-FDG, (99m)Tc-Annexin V, and (18)F-C-SNAT cell-associated radioactivity correlated well to levels of cell death (R(2) > 0.8; P 0.05). A similar pattern of response was observed in two human NSCLC cell lines following carboplatin treatment. EL-4 tumor uptake of (99m)Tc-Annexin V and (18)F-C-SNAT were increased 1.4- and 2.1-fold, respectively, in drug-treated versus naïve control animals (P < 0.05), although (99m)Tc-Annexin V binding did not correlate to ex vivo TUNEL staining of tissue sections. A differential response was not observed with either (18)F-FDG or (18)F-ML-10. CONCLUSIONS: We have demonstrated here that (18)F-C-SNAT can sensitively detect drug-induced cell death in murine lymphoma and human NSCLC. Despite favorable image contrast obtained with (18)F-C-SNAT, the development of next-generation derivatives, using the same novel and promising uptake mechanism, but displaying improved biodistribution profiles, are warranted for maximum clinical utility

    Steep rise in norovirus cases and emergence of a new recombinant strain GII.P16-GII.2, Germany, winter 2016

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    Since early November 2016, the number of laboratory-confirmed norovirus infections reported in Germany has been increasing steeply. Here, we report the detection and genetic characterisation of an emerging norovirus recombinant, GII.P16-GII.2. This strain was frequently identified as the cause of sporadic cases as well as outbreaks in nine federal states of Germany. Our findings suggest that the emergence of GII.P16-GII.2 contributed to rising case numbers of norovirus gastroenteritis in Germany

    Formed Metal Products and Methods of Making the Same

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    Provided herein are methods of forming a metal product, including applying a water soluble formability film to the metal blank and/or applying a network polymer preprime (e.g., a hybrid organic-inorganic preprime, or a heat-resistant hybrid preprime) to the metal blank, forming the metal blank into a formed metal product, and optionally removing the formability film. A removable formability film and/or a preprime can improve the formability of an aluminum alloy and replace lubricants that used for forming processes by reducing the coefficient of friction of the metal product surface. Further, employing a water soluble polymer film eliminates lubricant removal for downstream processing. The formability film and/or preprime can include chemical additives that provide additional surface properties. The methods of processing the aluminum alloy products described herein provide a more efficient method for producing aluminum alloy products, as required by end users (e.g., original equipment manufacturers (OEMs))

    PET imaging of tumor glycolysis downstream of hexokinase through noninvasive measurement of pyruvate kinase M2

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    Cancer cells reprogram their metabolism to meet increased biosynthetic demands, commensurate with elevated rates of replication. Pyruvate kinase M2 (PKM2) catalyzes the final and rate-limiting step in tumor glycolysis, controlling the balance between energy production and the synthesis of metabolic precursors. We report here the synthesis and evaluation of a positron emission tomography (PET) radiotracer, [(11)C]DASA-23, that provides a direct noninvasive measure of PKM2 expression in preclinical models of glioblastoma multiforme (GBM). In vivo, orthotopic U87 and GBM39 patient-derived tumors were clearly delineated from the surrounding normal brain tissue by PET imaging, corresponding to exclusive tumor-associated PKM2 expression. In addition, systemic treatment of mice with the PKM2 activator TEPP-46 resulted in complete abrogation of the PET signal in intracranial GBM39 tumors. Together, these data provide the basis for the clinical evaluation of imaging agents that target this important gatekeeper of tumor glycolysis
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