499 research outputs found

    A field-extrema hysteresis loss model for high-frequency ferrimagnetic materials

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    We present a new field-extrema hysteresis loss model (FHM) for high-frequency ferrimagnetic materials, along with a parameter identification procedure. The model does not involve solving an ordinary differential equation (ODE) and is asymmetric in that it works well under dc bias conditions. In the proposed model, the loss calculations are based on the extrema values of the fields. The model includes the effects of magnetic saturation as well as frequency effects. The model is comparable in accuracy to the ODE-based Jiles-Atherton model, but retains the convenience and computational efficiency of an empirical model. We demonstrate a procedure to characterize the model parameters using the Jiles-Atherton model. We compare magnetic hysteresis loss calculated by our new model with a full time-domain solution, as well as an empirical model, for a sample high-frequency ferrite. We demonstrate the use of the model, and validate the model, by calculating magnetic loss in an EI core inductor operating as the filter inductor in a buck converter. The model and identification procedure are being endorsed as a useful framework for computing magnetic loss in the context of automated magnetic device design

    Archeota, Fall 2019

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    This is the Fall 2019 issue of Archeota, the official publication of SJSU SAASC. Archeota is a platform for students to contribute to the archival conversation. It is written BY students, FOR students. It provides substantive content on archival concerns and issues, and promotes career development in the field of archival studies. Archeota upholds the core values of the archival profession. It is a semiannual publication of the Student Chapter of the Society of American Archivists at the San Jose State University School of Information.https://scholarworks.sjsu.edu/saasc_archeota/1010/thumbnail.jp

    STAT3-Deficient hyperimmunoglobulin E syndrome: report of a case with orofacial granulomatosis–like disease

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    Hyperimmunoglobulin E syndrome (HIES) is a rare heterogeneous primary immunodeficiency disorder characterized by infections of the lung and skin, elevated serum immunoglobulin E, and involvement of soft and bony tissues. Autosomal dominant HIES and related disorders are caused by defects in the Janus activated kinase–signal transducer and activator of transcription signaling pathway, leading to reduced numbers of T helper cell type 17 and impaired production of interleukin (IL)-17 A, IL-17 F, and IL-22. In addition, neutrophils have chemotactic defects, resulting in impaired responses at skin and lung sites. We report here a case of orofacial granulomatosis–like disease in a teenage boy ultimately found to have autosomal dominant HIES caused by a heterozygous mutation in the STAT3 gene

    C1 inhibitor deficiency: 2014 United Kingdom consensus document

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    C1 inhibitor deficiency is a rare disorder manifesting with recurrent attacks of disabling and potentially life-threatening angioedema. Here we present an updated 2014 United Kingdom consensus document for the management of C1 inhibitor-deficient patients, representing a joint venture between the United Kingdom Primary Immunodeficiency Network and Hereditary Angioedema UK. To develop the consensus, we assembled a multi-disciplinary steering group of clinicians, nurses and a patient representative. This steering group first met in 2012, developing a total of 48 recommendations across 11 themes. The statements were distributed to relevant clinicians and a representative group of patients to be scored for agreement on a Likert scale. All 48 statements achieved a high degree of consensus, indicating strong alignment of opinion. The recommendations have evolved significantly since the 2005 document, with particularly notable developments including an improved evidence base to guide dosing and indications for acute treatment, greater emphasis on home therapy for acute attacks and a strong focus on service organisation. This article is protected by copyright. All rights reserved

    Signal transducer and activator of transcription 2 deficiency is a novel disorder of mitochondrial fission

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    Defects of mitochondrial dynamics are emerging causes of neurological disease. In two children presenting with severe neurological deterioration following viral infection we identified a novel homozygous STAT2 mutation, c.1836C4A (p.Cys612Ter), using whole exome sequencing. In muscle and fibroblasts from these patients, and a third unrelated STAT2-deficient patient, we observed extremely elongated mitochondria. Western blot analysis revealed absence of the STAT2 protein and that the mitochondrial fission protein DRP1 (encoded by DNM1L) is inactive, as shown by its phosphorylation state. All three patients harboured 15 decreased levels of DRP1 phosphorylated at serine residue 616 (P-DRP1S616), a post-translational modification known to activate DRP1, and increased levels of DRP1 phosphorylated at serine 637 (P-DRP1S637), associated with the inactive state of the DRP1 GTPase. Knockdown of STAT2 in SHSY5Y cells recapitulated the fission defect, with elongated mitochondria and decreased PDRP1 S616 levels. Furthermore the mitochondrial fission defect in patient fibroblasts was rescued following lentiviral transduction with wild-type STAT2 in all three patients, with normalization of mitochondrial length and increased P-DRP1S616 levels. Taken 20 together, these findings implicate STAT2 as a novel regulator of DRP1 phosphorylation at serine 616, and thus of mitochondrial fission, and suggest that there are interactions between immunity and mitochondria. This is the first study to link the innate immune system to mitochondrial dynamics and morphology. We hypothesize that variability in JAK-STAT signalling may contribute to the phenotypic heterogeneity of mitochondrial disease, and may explain why some patients with underlying mitochondrial disease decompensate after seemingly trivial viral infections. Modulating JAK-STAT activity may represent a novel 25 therapeutic avenue for mitochondrial diseases, which remain largely untreatable. This may also be relevant for more common neurodegenerative diseases, including Alzheimer’s, Huntington’s and Parkinson’s diseases, in which abnormalities of mitochondrial morphology have been implicated in disease pathogenesis

    P1-162: Cardiac leiomyoma: primary or benign metastasizing?

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    Environmental Fit: A Model for Assessing and Treating Problem Behavior Associated with Curricular Difficulties in Children with Autism Spectrum Disorders

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    Theoretical considerations suggest that problem behavior should increase when a child’s competency does not match the curricular demands of the environment (i.e., when there is poor environmental fit). In the present study, environmental fit was examined for six children with autism spectrum disorders. Results indicated that the children exhibited high rates of problem behavior associated with poor motor or academic competency. Curricular modifications resulted in (a) a decrease in the level of problem behavior, (b) an increase in the percentage of task steps completed correctly, and (c) improved affect. Adults who worked with the children reported ease of intervention techniques. The concept of environmental fit and its usefulness in guiding both assessment of and intervention for problem behavior are discussed

    Hospitalisation following therapeutic community drug and alcohol treatment for young people with and without a history of criminal conviction

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    Introduction: This study examines the association between treatment in a therapeutic community for adolescents with drug and alcohol problems on hospitalisation outcomes up to 15 years later for all clients, and separately for those with and without a history of criminal conviction. Method: A quasi-experimental design was used to examine the linked administrative health and criminal justice records for all adolescents admitted to the Program for Adolescent Life Management (PALM) from January 2001 to December 2016 (n = 3059) in Sydney, Australia. ICD-10AM codes were used to designate hospitalisation outcomes as either physical injury, mental health problems, substance use disorders, or organic illness. The treatment and comparison groups were matched on factors associated with program retention, resulting in a final sample of 1266 clients. We examined the rate of hospitalisation up to 15 years posttreatment for all clients and stratified by prior conviction status using Cox regression analyses. Results: The treatment group had significantly lower rates of hospitalisation for a physical injury (HR = 0.77 [95% CI = 0.61–0.98]), mental health problem (HR = 0.62 [95% CI = 0.47–0.81]), substance use disorder (HR = 0.59 [95% CI = 0.47–0.75]), and organic illness (HR = 0.71 [95% CI = 0.55–0.92]). There was a significant interaction between treatment and prior criminal conviction status on rate of hospitalisation for physical injury, suggesting that the effect of treatment on physical injury was significantly greater for clients with a prior criminal conviction. Conclusions: Adolescents who engage in a therapeutic community treatment program may have a long-lasting reduction in the risk of subsequent hospitalisation. This also appears to apply to those with a history of criminal conviction

    In vivo killing of Staphylococcus aureus using a light-activated antimicrobial agent

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    Background: The widespread problem of antibiotic resistance in pathogens such as Staphylococcus aureus has prompted the search for new antimicrobial approaches. In this study we report for the first time the use of a light-activated antimicrobial agent, methylene blue, to kill an epidemic methicillin-resistant Staphylococcus aureus (EMRSA-16) strain in two mouse wound models.Results: Following irradiation of wounds with 360 J/cm(2) of laser light (670 nm) in the presence of 100 mu g/ml of methylene blue, a 25-fold reduction in the number of viable EMRSA was seen. This was independent of the increase in temperature of the wounds associated with the treatment. Histological examination of the wounds revealed no difference between the photodynamic therapy (PDT)-treated wounds and the untreated wounds, all of which showed the same degree of inflammatory infiltration at 24 hours.Conclusion: The results of this study demonstrate that PDT is effective at reducing the total number of viable EMRSA in a wound. This approach has promise as a means of treating wound infections caused by antibiotic-resistant microbes as well as for the elimination of such organisms from carriage sites
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