2,554 research outputs found

    Some thermophysical property measurements of porous ceramic ''Glassrock''

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    Thermophysical properties of porous ceramic material - thermal conductivity, specific heat, density, and porosity measurement

    Rapid submarine ice melting in the grounding zones of ice shelves in West Antarctica.

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    Enhanced submarine ice-shelf melting strongly controls ice loss in the Amundsen Sea embayment (ASE) of West Antarctica, but its magnitude is not well known in the critical grounding zones of the ASE's major glaciers. Here we directly quantify bottom ice losses along tens of kilometres with airborne radar sounding of the Dotson and Crosson ice shelves, which buttress the rapidly changing Smith, Pope and Kohler glaciers. Melting in the grounding zones is found to be much higher than steady-state levels, removing 300-490 m of solid ice between 2002 and 2009 beneath the retreating Smith Glacier. The vigorous, unbalanced melting supports the hypothesis that a significant increase in ocean heat influx into ASE sub-ice-shelf cavities took place in the mid-2000s. The synchronous but diverse evolutions of these glaciers illustrate how combinations of oceanography and topography modulate rapid submarine melting to hasten mass loss and glacier retreat from West Antarctica

    Experimental signatures of the quantum-classical transition in a nanomechanical oscillator modeled as a damped driven double-well problem

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    We demonstrate robust and reliable signatures for the transition from quantum to classical behavior in the position probability distribution of a damped double-well system using the Qunatum State Diffusion approach to open quantum systems. We argue that these signatures are within experimental reach, for example in a doubly-clamped nanomechanical beam.Comment: Proceedings of the conference FMQT 1

    Actin polymerization-dependent activation of Cas-L promotes immunological synapse stability

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    This work was supported by National Institutes of Health Common Fund through a Nanomedicine Development Center PN2EY016586 (MLD, MPS). OH and KA were Cas-L coordinates T-cell actin cytoskeleton 2 supported by NIH grants R01 AI068963-01A2 and R01 AI088106-01A1. The Wellcome Trust and the Kennedy Institute of Rheumatology Trust supported MLD

    Comparison of Narcotic Prescribing Habits Between Trainee and Attending Orthopaedic Surgeons

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    Background: Orthopaedic surgeons are among the highest prescribing physicians of narcotics to opioidnaïve patients. Despite the current opioid epidemic, few studies have specifically quantified the appropriate amount of opioids necessary for postoperative pain control. We hypothesized a significant variability in the quantity of postoperative opioids prescribed among trainee (ie, residents and fellows) and attending surgeons at a single institution. Methods: Postoperative narcotic prescribing habits were assessed using an anonymous survey. Ultimately, 28 trainee physicians and 17 attending physicians responded to the survey (86.5%). The survey recorded the amount of 5-mg oxycodone tablets that were commonly prescribed to manage pain after various typical orthopaedic procedures (eg, total knee arthroplasty). Non-narcotic analgesic use was also measured. Mean, standard deviation, and variance values were calculated, with significance set at α = 0.05. Results: After the following procedures, the respondents reported prescribing the following quantities of 5-mg oxycodone tablets: total knee arthroplasty, 56 (SD, 16); total hip arthroplasty, 53 (SD, 13); anterior cruciate ligament reconstruction, 38 (SD, 16); partial meniscectomy, 23 (SD, 14); arthroscopic rotator cuff repair, 39 (SD, 16); carpal tunnel release, 10 (SD, 10); A1 pulley release for treating trigger finger, 9 (SD, 9); open reduction and internal fixation (ORIF) for treating distal radius fractures, 32 (SD, 16); and ORIF for treating ankle fractures, 39 (SD, 15). Statistically significant variation existed between trainee and attending physicians for total hip arthroplasty and A1 pulley release. There was no difference for acetaminophen or nonsteroidal anti-inflammatory drugs, with about 70% of patients receiving at least one of these adjuncts. Conclusions: Variability exists in postoperative opioid prescribing habits between trainee and attending physicians at the academic training institution we accessed. In light of the ongoing opioid epidemic, institutions may benefit from standardized postoperative pain protocols

    Advanced solar dynamic space power systems perspectives, requirements and technology needs

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    Projected NASA, Civil, Commercial, and Military missions will require space power systems of increased versatility and power levels. The Advanced Solar Dynamic (ASD) Power systems offer the potential for efficient, lightweight, survivable, relatively compact, long-lived space power systems applicable to a wide range of power levels (3 to 300 kWe), and a wide variety of orbits. The successful development of these systems could satisfy the power needs for a wide variety of these projected missions. Thus, the NASA Lewis Research Center has embarked upon an aggressive ASD reserach project under the direction of NASA's Office of Aeronautics and Space Technology (DAST). The project is being implemented through a combination of in-house and contracted efforts. Key elements of this project are missions analysis to determine the power systems requirements, systems analysis to identify the most attractive ASD power systems to meet these requirements, and to guide the technology development efforts, and technology development of key components

    Accepting higher morbidity in exchange for sacrificing fewer animals in studies developing novel infection-control strategies.

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    Preventing bacterial infections from becoming the leading cause of death by the year 2050 requires the development of novel, infection-control strategies, building heavily on biomaterials science, including nanotechnology. Pre-clinical (animal) studies are indispensable for this development. Often, animal infection outcomes bear little relation to human clinical outcome. Here, we review conclusions from pathogen-inoculum dose-finding pilot studies for evaluation of novel infection-control strategies in murine models. Pathogen-inoculum doses are generally preferred that produce the largest differences in quantitative infection outcome parameters between a control and an experimental group, without death or termination of animals due to having reached an inhumane end-point during the study. However, animal death may represent a better end-point for evaluation than large differences in outcome parameters or number of days over which infection persists. The clinical relevance of lower pre-clinical outcomes, such as bioluminescence, colony forming units (CFUs) retrieved or more rapid clearance of infection is unknown, as most animals cure infection without intervention, depending on pathogen-species and pathogen-inoculum dose administered. In human clinical practice, patients suffering from infection present to hospital emergency wards, frequently in life-threatening conditions. Animal infection-models should therefore use prevention of death and recurrence of infection as primary efficacy targets to be addressed by novel strategies. To compensate for increased animal morbidity and mortality, animal experiments should solely be conducted for pre-clinical proof of principle and safety. With the advent of sophisticated in vitro models, we advocate limiting use of animal models when exploring pathogenesis or infection mechanisms
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