2,976 research outputs found

    Sudden hearing loss as an early detector of multiple sclerosis: a systematic review

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    To evaluate whether Sudden Sensorineural Hearing Loss (S-SNHL) may be an early symptom of Multiple Sclerosis (MS). A systematic review was conducted using the following keywords: "Multiple sclerosis, hearing loss, sudden hearing loss, vertigo, tinnitus, magnetic resonance imaging, otoacoustic emission, auditory brainstem responses, white matter lesions, sensorineural hearing loss, symptoms of MS and otolaryngology, nerve disease and MS". Only the articles that included results of at least one auditory test and MRI were considered. We evaluated the prevalence of SNHL in patients with MS, the presence of different forms of SNHL (S-SNHL and Progressive SNHL (P-SNHL)) and their correlation with the stage of MS, the results of electrophysiological tests, and the location (if any) of MS lesions as detected by white matter hyperintensities in the MRI. We reviewed a total of 47 articles, which included 29 case reports, 6 prospective studies, 6 cohort studies, 4 case-control studies, and 2 retrospective studies. 25% of patients suffered from SNHL. S-SNHL typically occurred in the early stage of the disease (92% of patients) and was the only presenting symptom in 43% of female subjects. Instead, P-SNHL occurred in the late stage of MS (88% of patients). Auditory Brainstem Responses (ABR) were abnormal in all MS patients with S-SNHL. When S-SNHL appeared during the early stage of the disease, MS lesions were found in the brain in 60% of patients and in the Internal Auditory Canal in 40% of patients. ABR remained abnormal after recovery. S-SNHL can be an early manifestation of MS and should always be considered in the differential diagnosis of this condition, especially in women. The pathophysiology can be explained by the involvement of microglia attacking the central and/or peripheral auditory pathways as indicated by WMHs

    Basic ideas and tools for projection-based model reduction of parametric partial differential equations

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    We provide first the functional analysis background required for reduced order modeling and present the underlying concepts of reduced basis model reduction. The projection-based model reduction framework under affinity assumptions, offline-online decomposition and error estimation is introduced. Several tools for geometry parametrizations, such as free form deformation, radial basis function interpolation and inverse distance weighting interpolation are explained. The empirical interpolation method is introduced as a general tool to deal with non-affine parameter dependency and non-linear problems. The discrete and matrix versions of the empirical interpolation are considered as well. Active subspaces properties are discussed to reduce high-dimensional parameter spaces as a pre-processing step. Several examples illustrate the methodologies

    Pedagogic research in anatomical sciences: a best practice guide

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    This article explores the background of anatomical educational research. It draws together research and our own personal experiences to propose a best practice piece for novice researchers in anatomical education. The article explores the domains of both qualitative, and quantitative methods as applied to anatomy pedagogy. It takes into consideration validity and what might be undertaken to increase validity and reliability. The article explores how both qualitative and quantitative data can be analysed and recommends top tips including: Identify your research questions and theoretical framework. Map out how you are going to answer your research questions. Consider collaborating with like-minded researchers in other countries: multi-centre studies have a better chance of getting published and carefully consider your target journal and suggestions for peer review, taking into consideration individuals expertise and potential conflicts of interests. This article is designed to be a guide to anyone starting anatomical research or experienced researchers looking for new methods and ideas

    Eco-Driving Strategy Implementation for Ultra-Efficient Lightweight Electric Vehicles in Realistic Driving Scenarios

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    This paper aims to provide a quantitative assessment of the effect of driver action and road traffic conditions in the real implementation of eco-driving strategies. The study specifically refers to an ultra-efficient battery-powered electric vehicle designed for energy-efficiency competitions. The method is based on the definition of digital twins of vehicle and driving scenario. The models are used in a driving simulator to accurately evaluate the power demand. The vehicle digital twin is built in a co-simulation environment between VI-CarRealTime and Simulink. A digital twin of the Brooklands Circuit (UK) is created leveraging the software RoadRunner. After validation with actual telemetry acquisitions, the model is employed offline to find the optimal driving strategy, namely, the optimal input throttle profile, which minimizes the energy consumption over an entire lap. The obtained reference driving strategy is used during real-time driving sessions at the dynamic driving simulator installed at Politecnico di Milano (DriSMi) to include the effects of human driver and road traffic conditions. Results assess that, in a realistic driving scenario, the energy demand could increase more than 20% with respect to the theoretical value. Such a reduction in performance can be mitigated by adopting eco-driving assistance systems

    Functional bioglass/carbon nanocomposite scaffolds from vat photopolymerization of a novel preceramic polymer-based nanoemulsion

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    Silicone polymers are already known as feedstock for a variety of silicate bioceramics, in the form of scaffolds with complex shapes, obtained by Vat Photopolymerization. Printing is enabled by using silicone blended with photocurable acrylates. The development of a particular silicate composition that functions as a glass or glass-ceramic precursor is possible by the addition of suitable oxide fillers (especially carbonate powders), suspended in the polymer blend. Oxides, from the fillers, easily react with silica left by the thermal transformation of the silicone. The fillers, however, also determine complications in Vat Photopolymerization, due to light scattering; in addition, local oxide concentrations generally impede the obtainment of glassy products. The present paper illustrates a simple solution to these issues, based on the inclusion of a Ca salt in nano-emulsion within a silicone-containing blend. Homogeneous printed samples are later converted into crack-free, fully amorphous ceramic composites, by firing at only 700 °C. The glass matrix, resembling 70S30C (70 % SiO2 and 30 % CaO) bioglass, is achieved according to the quasi-molecular CaO distribution. The secondary phase, promoted by treatment in N2 atmosphere and consisting of pyrolytic carbon, provides a marked photothermal effect

    Characteristics of Submucous Myomas and the Risk of Anemia

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    Background and Objectives: Uterine fibroids still represent the most common indication for hysterectomy for benign pathologies. In the United States, more than 479,000 hysterectomies are performed annually, 46.6% for myomas and 47.7% in women aged from 18 to 44 years. By applying appropriateness criteria to this procedure, it has been estimated that overuse ranges from 16 to 70%. One of the main reasons that induce patients and gynecologists to consider hysterectomy is represented by severe anemia. Materials and Methods: This is a retrospective cohort study of 202 patients with uterine fibroids diagnosed by transvaginal ultrasound who underwent a hysteroscopic procedure. Myoma grade, size, location, and number were assessed by transvaginal scan and office hysteroscopy and correlated to the pre-treatment hemoglobin level. Results: Univariate analysis showed that anemia does not have a statistically significant association with myoma number and with age considered as a numerical predictor. In the patients with myoma type 0, there is a possibility of 81% having anemia regardless of menorrhagia. On the contrary, in patients with myoma type 1 or type 2, the possibility of having anemia varies according to the presence or absence of menorrhagia. If there is menorrhagia, the risk of moderate anemia is only present for myomas >60 mm. Conclusions: The results of this study may contribute to defining objective criteria for the management of submucous myomas and anemia. Our data suggest that submucosal myomas type 0 >10 mm should always be treated, putting patients at risk for anemia. Myomas type 2 and 3 should be treated for the risk of anemia in the presence of menorrhagia episodes or if > of 60 mm. Adequate management of anemia and myomas could reduce the rate of unnecessary hysterectomies

    POD‐identification reduced order model of linear transport equations for control purposes

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    Intrusive reduced order modeling techniques require access to the solver's discretization and solution algorithm, which are not available for most computational fluid dynamics codes. Therefore, a nonintrusive reduction method that identifies the system matrix of linear fluid dynamical problems with a least-squares technique is presented. The methodology is applied to the linear scalar transport convection-diffusion equation for a 2D square cavity problem with a heated lid. The (time-dependent) boundary conditions are enforced in the obtained reduced order model (ROM) with a penalty method. The results are compared and the accuracy of the ROMs is assessed against the full order solutions and it is shown that the ROM can be used for sensitivity analysis by controlling the nonhomogeneous Dirichlet boundary conditions

    Effects of balloon injury on neointimal hyperplasia in steptozotocin-induced diabetes and in hyperinsulinemic nondiabetic pancreatic islet-transplanted rats.

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    BACKGROUND: The mechanisms of increased neointimal hyperplasia after coronary interventions in diabetic patients are still unknown. METHODS AND RESULTS: Glucose and insulin effects on in vitro vascular smooth muscle cell (VSMC) proliferation and migration were assessed. The effect of balloon injury on neointimal hyperplasia was studied in streptozotocin-induced diabetic rats with or without adjunct insulin therapy. To study the effect of balloon injury in nondiabetic rats with hyperinsulinemia, pancreatic islets were transplanted under the kidney capsule in normal rats. Glucose did not increase VSMC proliferation and migration in vitro. In contrast, insulin induced a significant increase in VSMC proliferation and migration in cell cultures. Furthermore, in VSMC culture, insulin increased MAPK activation. A reduction in neointimal hyperplasia was consistently documented after vascular injury in hyperglycemic streptozotocin-induced diabetic rats. Insulin therapy significantly increased neointimal hyperplasia in these rats. This effect of hyperinsulinemia was totally abolished by transfection on the arterial wall of the N17H-ras-negative mutant gene. Finally, after experimental balloon angioplasty in hyperinsulinemic nondiabetic islet-transplanted rats, a significant increase in neointimal hyperplasia was observed. CONCLUSIONS: In rats with streptozotocin-induced diabetes, balloon injury was not associated with an increase in neointimal formation. Exogenous insulin administration in diabetic rats and islet transplantation in nondiabetic rats increased both blood insulin levels and neointimal hyperplasia after balloon injury. Hyperinsulinemia through activation of the ras/MAPK pathway, rather than hyperglycemia per se, seems to be of crucial importance in determining the exaggerated neointimal hyperplasia after balloon angioplasty in diabetic animals

    MRI in prostate cancer diagnosis: do we need to add standard sampling? A review of the last 5 years

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    INTRODUCTION: In recent years, evidence has accrued to support the introduction of multiparametric magnetic resonance imaging (mpMRI) in the prostate cancer diagnostic pathway. The exact role of mpMRI in different settings is not widely agreed. In this review, we look at the use of MRI in three groups of men: biopsy naive men, those with a previous negative biopsy and those with a previous positive biopsy suitable for active surveillance. MATERIAL AND METHODS: An electronic MEDLINE/PubMed search up to 24th January 2018 was performed, using the search terms (prostate cancer OR prostate adenocarcinoma) AND (MRI OR magnetic resonance) AND (biopsy naive OR active surveillance OR prior negative biopsy OR no prior biopsy). Only those studies which reported detection rates of standard biopsy and MRI-targeted biopsy, where all men had both an MRI and standard biopsy were included. RESULTS: In total 34 articles were included (14 biopsy naive, 10 prior negative biopsy, and 10 prior positive biopsy). MRI-targeted biopsy consistently resulted in greater detection of clinically significant prostate cancer, and a lower detection of clinically insignificant prostate cancer, across all three patient populations. This effect was most prominent in men with at least one previous negative biopsy, and least prominent in men on active surveillance. In the presence of a negative mpMRI detection of csPCa found at systematic biopsy ranged from 0 to 20%. CONCLUSIONS: MRI-targeted biopsy is more efficient than standard biopsy in detecting clinically significant disease in men with a positive MRI, and results in less detection of clinically insignificant cancer. In men with a negative MRI, a significant minority of men will have clinically significant cancer detected on systematic biopsy
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