25 research outputs found

    THE EFFECTS OF TEMPERATURE DEPENDENT VISCOSITY AND VISCOUS DISSIPATION ON MHD CONVECTION FLOW FROM AN ISOTHERMAL HORIZONTAL CIRCULAR CYLINDER IN THE PRESENCE OF STRESS WORK AND HEAT GENERATION

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    Temperature dependent viscosity and Viscous Dissipation effects are considered on hydromagnetic natural convection flow from horizontal circular cylinder immersed in an electrically conducting fluid with viscosity proportional to a linear function of temperature in the presence of stress work and heat generation. The partial differential governing equations are transformed to dimensionless forms. The numerical computations are carried out for several values of physical parameters involved in the transformed equations. The resulting nonlinear system of partial differential equations is solved numerically by Keller box method which is an implicit finite difference technique with Newton's linearization method. The features of the flow and heat transfer characteristics for different values of the governing parameters are analyzed and discussed. To support the accuracy of the numerical results, a comparison is made with known results from the open literature for some particular cases of the present study and the results are found to be in good agreement

    Brain and spinal stimulation therapies for phantom limb pain: a systematic review.

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    BACKGROUND: Although many treatments exist for phantom limb pain (PLP), the evidence supporting them is limited and there are no guidelines for PLP management. Brain and spinal cord neurostimulation therapies are targeted at patients with chronic PLP but have yet to be systematically reviewed. OBJECTIVE: To determine which types of brain and spinal stimulation therapy appear to be the best for treating chronic PLP. DESIGN: Systematic reviews of effectiveness and epidemiology studies, and a survey of NHS practice. POPULATION: All patients with PLP. INTERVENTIONS: Invasive interventions - deep brain stimulation (DBS), motor cortex stimulation (MCS), spinal cord stimulation (SCS) and dorsal root ganglion (DRG) stimulation. Non-invasive interventions - repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS). MAIN OUTCOME MEASURES: Phantom limb pain and quality of life. DATA SOURCES: Twelve databases (including MEDLINE and EMBASE) and clinical trial registries were searched in May 2017, with no date limits applied. REVIEW METHODS: Two reviewers screened titles and abstracts and full texts. Data extraction and quality assessments were undertaken by one reviewer and checked by another. A questionnaire was distributed to clinicians via established e-mail lists of two relevant clinical societies. All results were presented narratively with accompanying tables. RESULTS: Seven randomised controlled trials (RCTs), 30 non-comparative group studies, 18 case reports and 21 epidemiology studies were included. Results from a good-quality RCT suggested short-term benefits of rTMS in reducing PLP, but not in reducing anxiety or depression. Small randomised trials of tDCS suggested the possibility of modest, short-term reductions in PLP. No RCTs of invasive therapies were identified. Results from small, non-comparative group studies suggested that, although many patients benefited from short-term pain reduction, far fewer maintained their benefits. Most studies had important methodological or reporting limitations and few studies reported quality-of-life data. The evidence on prognostic factors for the development of chronic PLP from the longitudinal studies also had important limitations. The results from these studies suggested that pre-amputation pain and early PLP intensity are good predictors of chronic PLP. Results from the cross-sectional studies suggested that the proportion of patients with severe chronic PLP is between around 30% and 40% of the chronic PLP population, and that around one-quarter of chronic PLP patients find their PLP to be either moderately or severely limiting or bothersome. There were 37 responses to the questionnaire distributed to clinicians. SCS and DRG stimulation are frequently used in the NHS but the prevalence of use of DBS and MCS was low. Most responders considered SCS and DRG stimulation to be at least sometimes effective. Neurosurgeons had mixed views on DBS, but most considered MCS to rarely be effective. Most clinicians thought that a randomised trial design could be successfully used to study neurostimulation therapies. LIMITATION: There was a lack of robust research studies. CONCLUSIONS: Currently available studies of the efficacy, effectiveness and safety of neurostimulation treatments do not provide robust, reliable results. Therefore, it is uncertain which treatments are best for chronic PLP. FUTURE WORK: Randomised crossover trials, randomised N-of-1 trials and prospective registry trials are viable study designs for future research. STUDY REGISTRATION: The study is registered as PROSPERO CRD42017065387. FUNDING: The National Institute for Health Research Health Technology Assessment programme

    Robotic Therapy for Phantom Limb Pain in Upper Limb Amputees

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    The system described in this paper combines virtual reality with haptic feedback to increase the level of immersion and invoke the sense of agency in patients with phantom limb pain with the aim of reducing perceived pain. This paper presents three case studies of an on-going clinical study. The initial results suggest an increased sense of embodiment of the virtual limb promotes a decrease in perceived levels of pain. The results strengthen the view that the cortical map does not fully “disappear” yet lays dormant

    A comparison of functional outcome between amputation and extension prosthesis in the treatment of congenital absence of the fibula with severe limb deformity

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    Purpose: Complete fibula absence often presents with significant lower-limb deformity. Parental counselling regarding management is paramount in achieving the optimum functional outcome. Amputation offers a single surgical event with minimal complications. This study compares outcomes with an amputation protocol to those using an extension prosthesis. // Method: Thirty-two patients were identified. Nine patients (2 males, 7 females; median age at assessment of 23.5 years) used an extension prosthesis. Twenty-three patients (16 males, 7 females; median age at assessment of eight years) underwent 25 amputations during childhood. Mobility was assessed using SIGAM and K scores. Quality of life was assessed using the PedsQL inventory questionnaire; pain by a verbal severity score. // Results: The 19 Syme and one Boyd amputation in 19 patients were performed early (mean age 15 months). Four Syme and one trans-tibial amputation in four patients took place in older children (mean age 6.6 years). Only two underwent tibial kyphus correction to aid prosthetic fitting. K scores were significantly higher (mean 4 vs 2) and pain scores lower in the amputation group allowing high impact activity compared with community ambulation with an extension prosthesis. The SIGAM and PedsQL scores were all better in the amputation group, but not significantly so. // Conclusion: Childhood amputation for severe limb length inequality and foot deformity in congenital fibula absence offers excellent short-term functional outcome with prosthetic support. The tibial kyphus does not need routine correction and facilitates prosthetic suspension. Accommodative extension prostheses offer reasonable long-term function but outcome scores are lower

    Some discussions of D. Fearnhead and D. Prangle's Read Paper "Constructing summary statistics for approximate Bayesian computation: semi-automatic approximate Bayesian computation"

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    This report is a collection of comments on the Read Paper of Fearnhead and Prangle (2011), to appear in the Journal of the Royal Statistical Society Series B, along with a reply from the authors

    Risk factors and outcomes associated with recurrent autoimmune hepatitis following liver transplantation

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    Background & Aims: Autoimmune hepatitis can recur after liver transplantation (LT), though the impact of recurrence on patient and graft survival has not been well characterized. We evaluated a large, international, multicenter cohort to identify the probability and risk factors associated with recurrent AIH and the association between recurrent disease and patient and graft survival.Methods: We included 736 patients (77% female, mean age 42 +/- 1 years) with AIH who underwent LT from January 1987 through June 2020, among 33 centers in North America, South America, Europe and Asia. Clinical data before and after LT, biochemical data within the first 12 months after LT, and immunosuppression after LT were analyzed to identify patients at higher risk of AIH recurrence based on histological diagnosis.Results: AIH recurred in 20% of patients after 5 years and 31% after 10 years. Age at LT <= 42 years (hazard ratio [HR] 3.15; 95% CI 1.22-8.16; p = 0.02), use of mycophenolate mofetil post-LT (HR 3.06; 95% CI 1.39-6.73; p = 0.005), donor and recipient sex mismatch (HR 2.57; 95% CI 1.39-4.76; p = 0.003) and high IgG pre-LT (HR 1.04; 95% CI 1.01-1.06; p = 0.004) were associated with higher risk of AIH recurrence after adjusting for other confounders. In multivariate Cox regression, recurrent AIH (as a time-dependent covariate) was significantly associated with graft loss (HR 10.79, 95% CI 5.37-21.66, p <0.001) and death (HR 2.53, 95% CI 1.48-4.33, p = 0.001).Conclusion: Recurrence of AIH following transplant is frequent and is associated with younger age at LT, use of mycophenolate mofetil post-LT, sex mismatch and high IgG pre-LT. We demonstrate an association between disease recurrence and impaired graft and overall survival in patients with AIH, highlighting the importance of ongoing efforts to better characterize, prevent and treat recurrent AIH.Lay summary: Recurrent autoimmune hepatitis following liver transplant is frequent and is associated with some recipient features and the type of immunosuppressive medications use. Recurrent autoimmune hepatitis negatively affects outcomes after liver transplantation. Thus, improved measures are required to prevent and treat this condition. (C) 2022 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.Cellular mechanisms in basic and clinical gastroenterology and hepatolog

    Investigating Variation Orders Causes in Iraqi Building Construction Projects

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    Changes are a common phenomenon in the construction industry, impacting the project's cost, time, and performance. The purpose of this work is to a comprehensive review relating to variation order causes. Also, the aim here is to determine variation order causes in the building’s construction. More importantly, explore the relationship between these causes. However, the importance of specifying the causes for change orders is the first step in managing variation orders to reduce the harmful effect on a project. The field survey was conducted for several institutions such as health (Karkh’s health), higher education (University of Baghdad and University of Kufa). As a result, a field visit was made to the project sites. They were then, Conducting interviews with the resident engineer, the consultant, and the contractor. A developer tool called cause (variation orders) breakdown structure (CBS) included 12 causes at the first level, including 103 sub-causes. There is a relationship between the variation orders causes, which is evident in the third level. The study recommends adopting (CBS) a comprehensive reference for variation order causes in projects due to facilitating their management processes. Future research could examine the relative importance of variation order causes, in addition to using a fuzzy cognitive map to find the extent of each cause’s influence on the other

    Some discussions of D. Fearnhead and D. Prangle's Read Paper "Constructing summary statistics for approximate Bayesian computation: semi-automatic approximate Bayesian computation"

    No full text
    This report is a collection of comments on the Read Paper of Fearnhead and Prangle (2011), to appear in the Journal of the Royal Statistical Society Series B, along with a reply from the authors
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