4,625 research outputs found

    Investigation of the role of Mg and Ca in the structure and durability of aluminoborosilicate glass

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    The structure and dissolution behaviour of Na 2 O·CaO·(15–x)Al 2 O 3 ·xB 2 O 3 ·SiO 2 and Na 2 O·MgO·(15–x)Al 2 O 3 ·xB 2 O 3 ·SiO 2 glasses, relevant to compositions of UK nuclear waste glass, have been investigated using nuclear magnetic resonance (NMR) spectroscopy and static dissolution experiments using the PCT protocol. Structural data from 11 B, 27 Al and 29 Si NMR analyses show that increasing the [B 2 O 3 ]/([Al 2 O 3 ] + [B 2 O 3 ]) ratio of the alkali-alkaline-earth aluminoborosilicate glasses led to an overall decrease in the proportion of non-silicate tetrahedral species ( IV Al + IV B) and a decrease in Si–O–X bonds (X[dbnd]B, Al). The Mg-containing glasses exhibited lower IV B fractions than their Ca-containing counterparts, which is thought to be due to the presence of IV Mg tetrahedra in the network. The measured corrosion rates were similar for both Ca and Mg-containing glasses although unexpectedly some Ca-containing glasses exhibited higher corrosion losses than the Mg-containing ones for time periods up to 112 d. However, there was evidence of a greater tendency to rate resumption in the Mg containing than the Ca containing ones. Alteration products were found to contain Ca, Si and Al with the Ca containing glasses and Ca, Mg, Si and Al with the Mg containing glasses; Na was not detected in the alteration products although its presence cannot be ruled out based on the data obtained

    Boundary Value Problems and Approximate Solutions

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    In this paper, we discuss about some basic things of boundary value problems. Secondly, we study boundary conditions involving derivatives and obtain finite difference approximations of partial derivatives of boundary value problems. The last section is devoted to determine an approximate solution for boundary value problems using Variational Iteration Method (VIM)and discuss the basic idea of He’s Variational Iteration Method and its  applications.Keywords: Boundary value problem, Boundary conditions, Variational Iteration Method, He’s Variational Iteration Method, Finite difference method, Standard 5-point formula, Iteration method, Relaxation method and standard analytic method

    Antipsychotic dose escalation as a trigger for Neuroleptic Malignant Syndrome (NMS): literature review and case series report

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    Background: “Neuroleptic malignant syndrome” (NMS) is a potentially fatal idiosyncratic reaction to any medication which affects the central dopaminergic system. Between 0.5% and 1% of patients exposed to antipsychotics develop the condition. Mortality rates may be as high as 55% and many risk factors have been reported. Although rapid escalation of antipsychotic dose is thought to be an important risk factor, to date it has not been the focus of a published case series or scientifically defined. <p/>Aims: To identify cases of NMS and review risk factors for its development with a particular focus on rapid dose escalation in the 30 days prior to onset. <p/>Methodology: A review of the literature on rapid dose escalation was undertaken and a pragmatic definition of “rapid dose escalation” was made. NMS cases were defined using DSM-IV criteria and systematically identified within a secondary care mental health service. A ratio of titration rate was calculated for each NMS patient and “rapid escalators” and “non rapid escalators” were compared. <p/>Results: 13 cases of NMS were identified. A progressive mean dose increase 15 days prior to the confirmed episode of NMS was observed (241.7mg/day during days 1-15 to 346.9mg/day during days 16-30) and the mean ratio of dose escalation for NMS patients was 1.4. Rapid dose escalation was seen in 5/13 cases and non rapid escalators had markedly higher daily cumulative antipsychotic dose compared to rapid escalators. <p/>Conclusions: Rapid dose escalation occurred in less than half of this case series (n=5, 38.5%), although there is currently no consensus on the precise definition of rapid dose escalation. Cumulative antipsychotic dose – alongside other known risk factors - may also be important in the development of NMS

    Fibrofog in daily life : An examination of ambulatory subjective and objective cognitive function in fibromyalgia

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    Research reported in this publication was supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases of the National Institutes of Health (award number K01AR064275; PI: Kratz). The Michigan Institute for Clinical & Health Research (MICHR: NIH award number UL1TR002240) provided subject recruitment support through the UMHealthResearch.org website. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.Peer reviewedPostprin

    The valuation of clean spread options: linking electricity, emissions and fuels

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    The purpose of the paper is to present a new pricing method for clean spread options, and to illustrate its main features on a set of numerical examples produced by a dedicated computer code. The novelty of the approach is embedded in the use of a structural model as opposed to reduced-form models which fail to capture properly the fundamental dependencies between the economic factors entering the production process

    Anticipating pulmonary complications after thoracotomy: the FLAM Score

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    OBJECTIVE: Pulmonary complications after thoracotomy are the result of progressive changes in the respiratory status of the patient. A multifactorial score (FLAM score) was developed to identify postoperatively patients at higher risk for pulmonary complications at least 24 hours before the clinical diagnosis. METHODS: The FLAM score, created in 2002, is based on 7 parameters (dyspnea, chest X-ray, delivered oxygen, auscultation, cough, quality and quantity of bronchial secretions). To validate the FLAM score, we prospectively calculated scores during the first postoperative week in 300 consecutive patients submitted to posterolateral thoracotomy. RESULTS: During the study, 60 patients (20%) developed pulmonary complications during the postoperative period. The FLAM score progressively increased in complicated patients until the fourth postoperative day (mean 13.5 ± 11.9). FLAM scores in patients with complications were significantly higher (p < 0.05) at least 24 hours before the clinical diagnosis of complication, compared to FLAM scores in uncomplicated patients. ROC curves analysis showed that the cut-off value of FLAM with the best sensitivity and specificity for pulmonary complications was 9 (area under the curve 0.97). Based on the highest FLAM scores recorded, 4 risk classes were identified with increasing incidence of pulmonary complications and mortality. CONCLUSION: Changes in FLAM score were evident at least 24 hours before the clinical diagnosis of pulmonary complications. FLAM score can be used to categorize patients according to risk of respiratory morbidity and mortality and could be a useful tool in the postoperative management of patients undergoing thoracotomy

    Remote Rehabilitation: A solution to Overloaded &amp; Scarce Health Care Systems

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    The population across Northern Europe is aging. Coupled with socio-economic challenges, health care systems are at risk of overloading and incurring unsustainable high costs. Rehabilitation services are used disproportionately by older people. One solution pertinent to rural areas is to change the model of rehabilitation to incorporate new technologies. This has the potential to free resources and reduce costs. However, implementation is challenging. In the Northern Periphery and Artic Programme (NPA), the Smart sensor Devices for rehabilitation and Connected health (SENDoc) project [1] is focused on introducing wearable sensor systems among elderly communities to support their rehabilitation. It is important to understand the context into which change is introduced. Therefore, an overview of the current state of health care systems in the four partner countries is presented, defining the concept of rehabilitation and how remote rehabilitation is currently delivered. Advantages (e.g. enhanced outcomes, less cost and enhanced patient engagement), and disadvantages of remote rehabilitation (e.g. complexity involved in the use of technology, design and safety issues) are discussed. It is concluded that the key advantage of remote rehabilitation is the potential to support change in patient behaviour, empowering active participation and living independently, with less need to travel for face-to-face sessions. Remote rehabilitation can make enhance quality of health care service delivery. However, all relevant stakeholders including medical staff and patients should be included in the design of the technology employed with a focus on simplicity, usability and robustness. Compliance with Security and the new GDPR regulation will be key to supporting remote rehabilitation. In addition, the diversity of available platforms and devices must also be supported to ensure interoperability. Finally, remote rehabilitation needs to be further validated in practice. Attempts to implement and sustain change should be cognisant of local and current organization of health care and of existing enablers and barriers

    Early star-forming galaxies and the reionization of the Universe

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    Star forming galaxies represent a valuable tracer of cosmic history. Recent observational progress with Hubble Space Telescope has led to the discovery and study of the earliest-known galaxies corresponding to a period when the Universe was only ~800 million years old. Intense ultraviolet radiation from these early galaxies probably induced a major event in cosmic history: the reionization of intergalactic hydrogen. New techniques are being developed to understand the properties of these most distant galaxies and determine their influence on the evolution of the universe.Comment: Review article appearing in Nature. This posting reflects a submitted version of the review formatted by the authors, in accordance with Nature publication policies. For the official, published version of the review, please see http://www.nature.com/nature/archive/index.htm
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