769 research outputs found
Substance use disorders in adolescents with attention deficit hyperactivity disorder: a 4-year follow-up study
Aim To examine the relationship between a childhood diagnosis of attention deficit hyperactivity disorder (ADHD) with or without oppositional defiant disorder (ODD)/conduct disorder (CD) and the development of later alcohol/drug use disorder [psychoactive substance use disorder (PSUD)] and nicotine dependence in a large European sample of ADHD probands, their siblings and healthy control subjects. Participants design and settingSubjects (n=1017) were participants in the Belgian, Dutch and German part of the International Multicenter ADHD Genetics (IMAGE) study. IMAGE families were identified through ADHD probands aged 5-17 years attending out-patient clinics, and control subjects from the same geographic areas. After a follow-up period (mean: 4.4 years) this subsample was re-assessed at a mean age of 16.4 years. Measurements PSUD and nicotine dependence were assessed using the Diagnostic Interview Schedule for Children, Alcohol Use Disorders Identification Test, Drug Abuse Screening Test and Fagerstrom test for Nicotine Dependence. Findings The ADHD sample was at higher risk of developing PSUD [hazard ratio (HR)=1.77, 95% confidence interval (CI)=1.05-3.00] and nicotine dependence (HR=8.61, 95% CI=2.44-30.34) than healthy controls. The rates of these disorders were highest for ADHD youth who also had CD, but could not be accounted for by this comorbidity. We did not find an increased risk of developing PSUD (HR=1.18, 95% CI=0.62-2.27) or nicotine dependence (HR=1.89, 95% CI=0.46-7.77) among unaffected siblings of ADHD youth. Conclusions A childhood diagnosis of attention deficit hyperactivity disorder is a risk factor for psychoactive substance use disorder and nicotine dependence in adolescence and comorbid conduct disorder, but not oppositional defiant disorder, further increases the risk of developing psychoactive substance use disorder and nicotine dependence
Topology Optimization for Enhancing Electric Machine Performance: A Review
Exploring the design space is essential in the pursuit of developing high-performance and power-dense electric machines. This article explores the transformative potential of topology optimization (TO) in enhancing the performance of electric machines. Conventional techniques for optimizing the design of electric machines use optimization algorithms to determine geometric variables within a predefined range. However, these methods are limited by manufacturing constraints and the designer's expertise in parameterization. On the other hand, topology optimization aims to enhance the performance of electric machines by manipulating the distribution of materials as a design factor. The enhancement is facilitated by additive manufacturing (AM), particularly via the manufacturing of intricate metal parts. In this paper, the main concepts of topology optimization in electric machines are reviewed. Firstly, the requirement for topology optimization is illustrated, and both the achievements and challenges of this technique over the traditional parametric optimization are described. Then, a description is given of different topology optimization methods that were reported in the literature. Finally, the development opportunities of this technology are shown in the electric machine design field.© 2024 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.European Union/HORIZON/101073250/E
A Review on Properties of 3D Printed Magnetic Cores for Electrical Machines: Additive Manufacturing Methods and Materials
Additive Manufacturing (AM) is a new topic in the field of electrical machines (EMs), offering the potential to overcome the limitations in the design of EMs. Through AM, complex 3D geometries and the utilization of Fe-Si cores with 6.5% silicon can be achieved, leading to enhanced EM performance without concerns about manufacturing cost and complexity. This paper provides an overview of various AM methods and materials used in manufacturing soft magnetic cores for EMs, with a particular emphasis on the multi-physics properties of these cores. Due to the distinct fusion processes in each AM method, the microstructural properties of the printed cores vary, leading to diverse multi-physics properties that require detailed investigation. The paper outlines both the benefits and challenges associated with AM techniques and materials. Importantly, it explores the detailed characteristics of Fe-Si and Fe-Co cores manufactured through different AM methods, comparing them with commercial laminations such as 35A300, JNEX Super Core, and Hiperco 50A.© 2024 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.European Union/HORIZON/101073250/E
Design Considerations of a New IPM Rotor With Efficient Utilization of PMs Enabled by Additive Manufacturing
This paper presents a new design concept for interior permanent magnet (IPM) rotor using the capabilities of additive manufacturing (AM). In conventional laminated IPM topology, the presence of rotor ribs is essential for maintaining the mechanical integrity of the rotor. However, these pole ribs are a primary contributor to flux leakage, leading to inefficient utilization of costly rare-earth PMs. Addressing this challenge, a rib-less IPM rotor is proposed that takes advantage of the AM potential which eliminates the need for traditional ribs while maintaining the structural integrity of the rotor. Nevertheless, the additively manufactured cores, in contrast to conventionally laminated rotor cores, demand specific design considerations, especially in terms of eddy current loss and structural performance. In this regard, a strategy involving the incorporation of shallow grooves on the rotor surface is employed to mitigate eddy current loss. The mechanical performance of the proposed topology is carefully examined, and the impact of pole geometry on rotor displacement induced by centrifugal forces is investigated. To evaluate the performance of the proposed topology, an optimization procedure based on response surface methodology is conducted for both the proposed rotor and a conventional IPM rotor. The results indicate that the proposed IPM topology can offer significantly more efficient utilization of PMs and enhanced torque rating by approximately 8% compared to the laminated IPM topology.European Union/Marie Sklodowska Curie DoctoralIndustrial Project (HORIZON-MSCA-2021-DN-01)/EMByAM (101073250)/E
The effect of methylphenidate on three forms of response inhibition in boys with AD/HD
Item does not contain fulltextThe current study was aimed at (a) investigating the effect of three doses methylphenidate (MPH) and placebo on inhibition of a prepotent response, inhibition of an ongoing response, and interference control in Attention Deficit/Hyperactivity Disorder (AD/HD), and (b) studying dose-response relations for the three forms of response inhibition. To meet these aims, the following tasks were selected: two versions of the Stop Paradigm for inhibition of a prepotent response, a Circle Tracing Task and a recently developed Follow Task for inhibition of an ongoing response, and the Stroop Color-Word Test and an Eriksen Flanker Task for interference control. These tasks were administered to 23 boys with AD/HD during four treatment conditions: 5 mg MPH, 10 mg MPH, 20 mg MPH, and placebo. A pseudorandomized, multiple-blind, placebo-controlled, within-subject design was used. As hypothesized, inhibitory control in children with AD/HD improved under MPH compared to placebo. However, this effect was only significant for inhibition of a prepotent response and inhibition of an ongoing response (as measured by the Follow Task), but not for interference control. The relation between treatment condition and response was linear. However, this linear relation was due to improved inhibitory control under MPH compared to placebo, because no effects of MPH dose were observed for any of the response inhibition measures
Avian malaria is absent in juvenile colonial herons (Ardeidae) but not Culex pipiens mosquitoes in the Camargue, Southern France
Apicomplexan blood parasites Plasmodium and Haemoproteus (together termed “Avian malaria”) and Leucocytozoon are widespread, diverse vector-transmitted blood parasites of birds, and conditions associated with colonial nesting in herons (Ardeidae) and other waterbirds appear perfect for their transmission. Despite studies in other locations reporting high prevalence of parasites in juvenile herons, juvenile Little Egrets (Egretta garzetta) previously tested in the Camargue, Southern France, had a total absence of malaria parasites. This study tested the hypotheses that this absence was due to insufficient sensitivity of the tests of infection; an absence of infective vectors; or testing birds too early in their lives. Blood was sampled from juveniles of four species shortly before fledging: Little Egret (n = 40), Cattle Egret (Bubulcus ibis; n = 40), Black-crowned Night-Heron (Nycticorax nycticorax, n = 40), and Squacco Heron (Ardeola ralloides; n = 40). Sensitive nested-Polymerase Chain Reaction was used to test for the presence of parasites in both birds and host-seeking female mosquitoes captured around the colonies. No malaria infection was found of in any of the heron species. Four different lineages of Plasmodium were detected in pooled samples of female Culex pipiens mosquitoes, including two in potentially infective mosquitoes. These results confirm that the absence of malaria parasites previously demonstrated in Little Egret is not due to methodological limitations. Although the prevalence of infection in mosquitoes was low, conditions within the colonies were suitable for transmission of Plasmodium. These colonial heron species may have evolved strategies for resisting malaria infection through physiological or behavioral mechanisms
Symptoms in first degree relatives of patients with rheumatoid arthritis:evaluation of cross-sectional data from the symptoms in persons at risk of rheumatoid arthritis (SPARRA) questionnaire in the PRe-clinical EValuation of Novel Targets in RA (PREVeNT-RA) Cohort
Abstract Background First-degree relatives (FDRs) of people with rheumatoid arthritis (RA) have a fourfold increased risk of developing RA. The Symptoms in Persons At Risk of Rheumatoid Arthritis (SPARRA) questionnaire was developed to document symptoms in persons at risk of RA. The aims of this study were (1) to describe symptoms in a cohort of FDRs of patients with RA overall and stratified by seropositivity and elevated CRP and (2) to determine if patient characteristics were associated with symptoms suggestive of RA. Methods A cross-sectional study of FDRs of patients with RA, in the PREVeNT-RA study, who completed a study questionnaire, provided a blood sample measured for rheumatoid factor, anti-CCP and CRP and completed the SPARRA questionnaire. Moderate/severe symptoms and symmetrical, small and large joint pain were identified and described. Symptoms associated with both seropositivity and elevated CRP were considered suggestive of RA. Logistic regression was used to determine if symptoms suggestive of RA were associated with patient characteristics. Results Eight hundred seventy participants provided all data, 43 (5%) were seropositive and 122 (14%) had elevated CRP. The most frequently reported symptoms were sleep disturbances (20.3%) and joint pain (17.9%). Symmetrical and small joint pain were 11.3% and 12.8% higher, respectively, in those who were seropositive and 11.5% and 10.7% higher in those with elevated CRP. In the logistic regression model, seropositivity, older age and feeling depressed were associated with increased odds of small and symmetrical joint pain. Conclusions This is the first time the SPARRA questionnaire has been applied in FDRs of patients with RA and has demonstrated that the presence of symmetrical and small joint pain in this group may be useful in identifying people at higher risk of developing RA
Community standards for open cell migration data
Cell migration research has become a high-content field. However, the quantitative information encapsulated in these complex and high-dimensional datasets is not fully exploited owing to the diversity of experimental protocols and non-standardized output formats. In addition, typically the datasets are not open for reuse. Making the data open and Findable, Accessible, Interoperable, and Reusable (FAIR) will enable meta-analysis, data integration, and data mining. Standardized data formats and controlled vocabularies are essential for building a suitable infrastructure for that purpose but are not available in the cell migration domain. We here present standardization efforts by the Cell Migration Standardisation Organisation (CMSO), an open community-driven organization to facilitate the development of standards for cell migration data. This work will foster the development of improved algorithms and tools and enable secondary analysis of public datasets, ultimately unlocking new knowledge of the complex biological process of cell migration
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