Design and modeling of a stellarator fusion reactor is a multidisciplinary effort that requires a tight integration between simulation of highly nonlinear multi-physics and representation of ...non-planar complex geometries. The critical current calculation and the design of the mechanical structures are among the most crucial aspects as they set size, cost, and time to build the stellarator. Because of the asymmetric and non-planar nature of its components the modeling of such figures of merit needs to be carried out at large scale, without the possibility of taking advantage of any particular symmetry. In this work we develop a three-dimensional model for the analysis of the magnetic field and forces, necessary for such considerations, for complex coil geometries, such as stellarators, where a two-dimensional approach can not provide accurate analyses and verification of assumptions. Moreover, this method can quickly generate a large amount of critical modeling data (e.g. Lorentz load, displacement and stresses) that could be integrated into a workflow for coil design optimization based on machine learning or other recent optimization tools.
Abstract Context Recently, there has been an increasing number of reports of incidental pulmonary embolism (PE) in patients undergoing chest computer tomography (CT) for reasons other than the ...research of suspected PE. Natural history of incidental PE remains unclear. Objectives To estimate the prevalence of incidental PE, to assess potential factors associated with incidental PE, and to evaluated its clinical history. Data Sources MEDLINE, EMBASE databases (up to January 2009). Study Selection Studies were included if the prevalence of incidental PE was assessed using CT scanning. Data Extraction The prevalence of incidental PE in these patients was documented. Separate data for inpatients and outpatients and according to the reason for CT scanning were collected. Weighted mean proportion of the prevalence of incidental PE was calculated. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to test the association with potential predictors of incidental PE. Results Twelve studies for a total of more than 10 thousand patients were included. The weighted mean prevalence of incidental PE was 2.6% (95% CI 1.9, 3.4). Hospitalization at the time of CT scanning and the presence of cancer were associated with a significantly increased risk of incidental PE (OR 4.27 and OR 1.80 respectively). Conclusions The prevalence of incidental PE is clinically relevant. Future studies are necessary to properly evaluate the clinical history of these patients.
•Evidence on resource use is limited to studies reporting mostly on the resource “time” and not always under real life conditions.•Administration and project management, study selection, data ...extraction, and critical appraisal seem to be very resource intensive, varying with the number of included studies, while protocol development, literature search, and study retrieval take less time.•Lack of experience and domain knowledge, lack of collaborative and supportive software, as well as lack of good communication and management can increase resource use during the systematic review process.
We aimed to map the resource use during systematic review (SR) production and reasons why steps of the SR production are resource intensive to discover where the largest gain in improving efficiency might be possible.
We conducted a scoping review. An information specialist searched multiple databases (e.g., Ovid MEDLINE, Scopus) and implemented citation-based and grey literature searching. We employed dual and independent screenings of records at the title/abstract and full-text levels and data extraction.
We included 34 studies. Thirty-two reported on the resource use—mostly time; four described reasons why steps of the review process are resource intensive. Study selection, data extraction, and critical appraisal seem to be very resource intensive, while protocol development, literature search, or study retrieval take less time. Project management and administration required a large proportion of SR production time. Lack of experience, domain knowledge, use of collaborative and SR-tailored software, and good communication and management can be reasons why SR steps are resource intensive.
Resource use during SR production varies widely. Areas with the largest resource use are administration and project management, study selection, data extraction, and critical appraisal of studies.
High-temperature superconducting-slotted cables, including the VIPER cable, are being investigated as possible candidates for winding the toroidal field coils of compact nuclear fusion machines, such ...as ARC. The higher performance of HTS materials in terms of magnetic fields and currents allows them to reduce their size compared to machines based on Nb alloys and compounds. However, compactness also means a closer interaction between the plasma products and the coils, creating new technological challenges to be faced. Among the others, the thermal effects induced on the superconducting materials by direct particles (i.e., neutrons), secondary particles and gamma-ray heating, will be stronger than for low-field larger machines and must be quantified. In this paper, a detailed thermo-magnetic model is built up using the software COMSOL Multiphysics to simulate the consequences of the D-T plasma operation products on the first turn of a toroidal field coil of the ARC preliminary machine design. The irradiation-induced heat load on the (RE)Ba 2 Cu 3 O 7-δ tapes, computed via Monte Carlo simulations, is used as input for the thermal analysis of the VIPER cable. At the same time, a homogenized T-A formulation is developed for checking the performance reduction in the current/field operating conditions.
We investigated whether the functional connections to the primary sensorimotor cortex (SMC) at rest are abnormal in 26 patients with amyotrophic lateral sclerosis (ALS) and whether such changes are ...related to the corticospinal tract (CST) damage, measured using diffusion tensor magnetic resonance imaging (DT MRI). ALS patients versus controls showed a significantly increased functional connectivity between the left SMC and the right cingulate cortex, parahippocampal gyrus, and cerebellum-crus II. No right SMC connectivity changes were found. The pattern of increased functional connectivity to the left SMC was more widespread when considering only patients with no CST DT MRI abnormalities than the whole group of patients. In this patient group, functional connectivity was also increased between the right SMC and the right parahippocampal gyrus. On the contrary, in ALS patients with CST damage (as assessed using DT MRI) versus controls, functional connectivity was increased between the left SMC and the right cingulate cortex only, while it was decreased between the right SMC and the right cerebellum-lobule VI. In ALS patients, disease severity correlated with reduced SMC functional connectivity. Functional brain changes do occur in ALS with mild disability. These changes might have a role in compensating for (limited) structural damage and might exhaust with increasing burden of disease pathology.
Understanding the electro-thermal behavior of high-temperature superconductor (HTS) materials is a critical aspect for designing efficient and reliable applications. In order to optimize cost and ...performance, one needs to understand the role played by the various layers of an HTS tape during a quench. On one hand, the electrical and thermal properties of the materials used in the manufacturing of those tapes (e.g., alloy substrate, silver, and copper) are well known. Knowledge of the functional dependence of the superconductor's resistivity ρ(J, T ) above the critical current in 2G HTS CCs is very limited. In the flux creep or normal state regime, the resistivity can be approximated by empirical laws. In the flux-flow regime, it is difficult to extract ρ(J, T ) due to the presence of Joule heating. In this contribution, using finite-element analysis, we present a method to retrieve the overcritical current resistivity, by estimating the amount of current, temperature, and heat present in the various layers.
Summary
Research or clinical experience abroad is often encouraged for early career professionals to enhance their future career prospects. If resources are available to facilitate this, we believe ...that a fellowship abroad should definitely be considered. It can be a great asset, but also an exciting and scary experience at the same time. We, Nicoletta and Mandy, medical doctors in Italy and the Netherlands, respectively, have been fortunate enough to gain abroad experience: Nicoletta in Birmingham, United Kingdom, for 12 months, doing a clinical research fellowship in the field of anticoagulation and atrial fibrillation, working with Prof. Gregory Lip, and Mandy in Hamilton, ON, Canada, for 13 months, undertaking a clinical research fellowship in the field of anticoagulation, stroke and atrial fibrillation, with Dr John Eikelboom, Prof. Jack Hirsh, Prof. Jeff Weitz and, Prof. Stuart Connolly. As we have both experienced the benefits but also the challenges resulting from these encounters, we hope that this forum piece will provide other early career professionals with helpful suggestions and, above all, fill them with excitement about an international training opportunity.
Cancer is a major risk factor for venous thromboembolism (VTE), and cancer-associated thrombosis (CAT) constitutes approximately 15-25% of all VTE cases. For decades, the standard treatment for CAT ...used to be daily subcutaneous low molecular weight heparin (LMWH). Data on the safety and efficacy of the direct oral anticoagulants (DOACs) in this population emerged only in recent years and specific DOACs were included into recent guidelines recommendations. In this narrative review of the literature, we reported the results of the phase III randomized controlled trials that evaluated the DOACs for the prevention and the acute treatment of CAT. For the acute phase treatment, the anti-Xa inhibitors (apixaban, edoxaban, rivaroxaban) showed better efficacy than LMWH in preventing VTE recurrence; however, rivaroxaban and edoxaban were also associated with an increased risk of bleeding events. For primary prevention of CAT in ambulatory cancer patients starting chemotherapy, apixaban and rivaroxaban showed better efficacy than placebo but a trend towards higher bleeding rates. Recent guidelines suggest the DOACs for the treatment of CAT in selected cancer patients (eg, low bleeding risk, no luminal gastrointestinal or genitourinary malignancies, no interfering medications). The DOACs are also suggested for primary thromboprophylaxis in selected ambulatory cancer patients at high risk of VTE (eg, Khorana score greater than or equal to2 prior to starting new chemotherapy, low bleeding risk, no interfering medications). Keywords: cancer, venous thromboembolism, apixaban, edoxaban, rivaroxaban
This study aimed to evaluate muscle oxidative function during exercise in amyotrophic lateral sclerosis patients (pALS) with non-invasive methods in order to assess if determinants of reduced ...exercise tolerance might match ALS clinical heterogeneity. 17 pALS, who were followed for 4 months, were compared with 13 healthy controls (CTRL). Exercise tolerance was assessed by an incremental exercise test on cycle ergometer measuring peak O
uptake (Formula: see textO
), vastus lateralis oxidative function by near infrared spectroscopy (NIRS) and breathing pattern (Formula: see textE
). pALS displayed: (1) 44% lower Formula: see textO
vs. CTRL (p < 0.0001), paralleled by a 43% decreased peak skeletal muscle oxidative function (p < 0.01), with a linear regression between these two variables (r
= 0.64, p < 0.0001); (2) 46% reduced Formula: see textE
vs. CTRL (p < 0.0001), achieved by using an inefficient breathing pattern (increasing respiratory frequency) from the onset until the end of exercise. Inefficient skeletal muscle O
function, when flanking the impaired motor units recruitment, is a major determinant of pALS clinical heterogeneity and working capacity exercise tolerance. CPET and NIRS are useful tools for detecting early stages of oxidative deficiency in skeletal muscles, disclosing individual impairments in the O
transport and utilization chain.
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