84 research outputs found

    Semi-classical limit of relativistic quantum mechanics

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    It is shown that the semi-classical limit of solutions to the Klein-Gordon equation gives the particle probability density that is in direct proportion to the inverse of the particle velocity. It is also shown that in the case of the Dirac equation a different result is obtained

    InaÄŤica kvantnoj mehanici, II dio: interferencija snopova iz jednog izvora

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    An interference experiment that tests the particle probability density given by the wave theory and quantum mechanics is suggested. The idea of this experiment is inspired by the philosophy of the model of the interacting particle.Predlaže se eksperiment za provjeru gustoće čestične vjerojatnosti prema valnoj teoriji i kvantnoj mehanici. Zamisao eksperimenta zasniva se na postavkama modela međudjelujućih čestica

    InaÄŤica kvantnoj mehanici, II dio: interferencija snopova iz jednog izvora

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    An interference experiment that tests the particle probability density given by the wave theory and quantum mechanics is suggested. The idea of this experiment is inspired by the philosophy of the model of the interacting particle.Predlaže se eksperiment za provjeru gustoće čestične vjerojatnosti prema valnoj teoriji i kvantnoj mehanici. Zamisao eksperimenta zasniva se na postavkama modela međudjelujućih čestica

    Comparison of osteoporosis pharmacotherapy fracture rates: Analysis of a marketScan® claims database cohort

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    Background: Several different classes of medications have been shown to be efficacious at preventing fractures in patients with osteoporosis. No study has compared real world efficacy at preventing fractures between all currently approved medications. Objectives: To directly compare the efficacy of all currently available osteoporosis medications by using a large population claims database. Methods: The Truven Health Analytics MarketScan® database from 2008 - 2012 was used to identify all patients who started a new osteoporosis medication. Patients who experienced a fracture after at least 12 months of treatment were identified and risk factors for fracture for all patients were recorded. Logistic regression was used to account for and quantify the contribution of risk factors, and to make direct comparisons between different osteoporosis medications. Results: A total of 51649 patients were included in the cohort, with an average age of 56 years. The overall incidence rate of fracture was 1.55 per 100 person - years of treatment. Orally administered medications had the lowest fracture rates, led by raloxifene and alendronate (1.24 and 1.54 respectively), while parenterally administered medications including teriparatide and zolerdonic acid had the highest rates (3.90 and 1.98 respectively). No statistically significant differences found between oral or parenterally administered bisphosphonate medications. Conclusions: While patients taking orally administered drugs including bisphosphonates had less frequent incident fracture no statistically significant differences were found between most drugs in head - to - head comparisons, even considering the route of administration of bisphosphonates. These findings support previous evidence that minimal differences in efficacy exist between different osteoporosis medications. This is the first study using a large database to compare all currently available osteoporosis treatments and will hopefully be augmented by further study to provide more evidence to make clinical decisions on osteoporosis medication use. © 2017 American Association of Neuropathologists, Inc

    Constraint handling strategies in Genetic Algorithms application to optimal batch plant design

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    Optimal batch plant design is a recurrent issue in Process Engineering, which can be formulated as a Mixed Integer Non-Linear Programming(MINLP) optimisation problem involving specific constraints, which can be, typically, the respect of a time horizon for the synthesis of various products. Genetic Algorithms constitute a common option for the solution of these problems, but their basic operating mode is not always wellsuited to any kind of constraint treatment: if those cannot be integrated in variable encoding or accounted for through adapted genetic operators, their handling turns to be a thorny issue. The point of this study is thus to test a few constraint handling techniques on a mid-size example in order to determine which one is the best fitted, in the framework of one particular problem formulation. The investigated methods are the elimination of infeasible individuals, the use of a penalty term added in the minimized criterion, the relaxation of the discrete variables upper bounds, dominancebased tournaments and, finally, a multiobjective strategy. The numerical computations, analysed in terms of result quality and of computational time, show the superiority of elimination technique for the former criterion only when the latter one does not become a bottleneck. Besides, when the problem complexity makes the random location of feasible space too difficult, a single tournament technique proves to be the most efficient one

    Doppler forward flow profiles of St. Jude Medical prosthetic valves in pediatric patients

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    In summary, this data on baseline and follow-up Doppler flow characteristics of small caliber SJM prosthetic valves should be extremely valuable for identifying valve dysfunction in children. Because of the high risk of developing valve obstruction, these children should be closely monitored with serial Doppler examinations.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/31454/1/0000375.pd

    Pressure-Regulated Volume Control vs Volume Control Ventilation in Infants After Surgery for Congenital Heart Disease

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    The objective of this investigation was to compare how two modes of positive pressure ventilation affect cardiac output, airway pressures, oxygenation, and carbon dioxide removal in children with congenital heart disease in the immediate postoperative period. The investigation used a one group pretest–post-test study design and was performed in the pediatric cardiac intensive care unit in a university-affiliated children's hospital. Nine infants were enrolled immediately after repair of tetralogy of Fallot (2) or atrioventricular septal defects (7) with mean weight = 5.5 kg (4.2–7.3 kg). Children were admitted to the pediatric cardiothoracic intensive care unit after complete surgical repair of their cardiac defect and stabilized on a Siemen's Servo 300 ventilator in volume control mode (VCV1) (volume-targeted ventilation with a square flow wave pattern). Tidal volume was set at 15 cc/kg (total). Hemodynamic parameters, airway pressures and ventilator settings, and an arterial blood gas were measured. Patients were then changed to pressure-regulated volume control mode (PRVC) (volume-targeted ventilation with decelerating flow wave pattern) with the tidal volume set as before. Measurements were repeated after 30 minutes. Patients were then returned to volume control mode (VCV2) and final measurements made after 30 minutes. The measurements and results are as follows:Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42385/1/246-22-3-233_10220233.pd

    DNA and Inflammatory Mediators in Bronchoalveolar Lavage Fluid From Children With Acute Inhalational Injuries:

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    Assess the feasibility of using serial bronchoalveolar lavage fluids (BALF) to characterize the course of cell damage and inflammation in airways of pediatric patients with acute burn or inhalation injury

    Managed Aquifer Recharge as a Tool to Enhance Sustainable Groundwater Management in California

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    A growing population and an increased demand for water resources have resulted in a global trend of groundwater depletion. Arid and semi-arid climates are particularly susceptible, often relying on groundwater to support large population centers or irrigated agriculture in the absence of sufficient surface water resources. In an effort to increase the security of groundwater resources, managed aquifer recharge (MAR) programs have been developed and implemented globally. MAR is the approach of intentionally harvesting and infiltrating water to recharge depleted aquifer storage. California is a prime example of this growing problem, with three cities that have over a million residents and an agricultural industry that was valued at 47 billion dollars in 2015. The present-day groundwater overdraft of over 100 km3 (since 1962) indicates a clear disparity between surface water supply and water demand within the state. In the face of groundwater overdraft and the anticipated effects of climate change, many new MAR projects are being constructed or investigated throughout California, adding to those that have existed for decades. Some common MAR types utilized in California include injection wells, infiltration basins (also known as spreading basins, percolation basins, or recharge basins), and low-impact development. An emerging MAR type that is actively being investigated is the winter flooding of agricultural fields using existing irrigation infrastructure and excess surface water resources, known as agricultural MAR. California therefore provides an excellent case study to look at the historical use and performance of MAR, ongoing and emerging challenges, novel MAR applications, and the potential for expansion of MAR. Effective MAR projects are an essential tool for increasing groundwater security, both in California and on a global scale. This chapter aims to provide an overview of the most common MAR types and applications within the State of California and neighboring semi-arid regions
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