148 research outputs found

    Instantaneous power analysis of three-phase linear load in the hyper-complex space

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    В настоящее время при решении прикладных задач повышения энергоэффективности трехфазных систем переменного тока общего назначения широко используются активные силовые фильтры, предназначенные для симметрирования нагрузки, подавления высокочастотных гармоник, уменьшения скачков напряжения и т.д. Алгоритмы управления данными силовыми полупроводниковыми устройствами реализуются в рамках геометрического, тензорного и алгебраического подходов, причем в последнем случае, основанном на использовании гиперкомплексных чисел, удается несколько упростить структуру управляющей части. Данный доклад посвящен анализу кватерниона мгновенной мощности применительно к несимметричным активно-реактивным цепям с целью определения его неактивных составляющих, подлежащих последующему исключению из общего потока электрической энергии в единицу времени.At present time in order to improve the power quality of AC three-phase systems the active power filters are used for load balancing, harmonic filtering, voltage flicker reduction etc. Control strategies for power semiconductor converters in these applications are implemented using the geometrical, tensor or algebraic approaches. With the last one it becomes possible to reduce the control block structure. This paper deals with an instantaneous power quaternion of unbalanced linear three-phase loads for obtaining information about the inactive component which is to be excluded from the AC electrical energy flows per unit of time

    Obtainment of bactericidal inkjet inks based on Ag-nanocomposites

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    In this study, ceramic inks were formulated that are able to develop bactericidal properties and are appropriate for application by inkjet printing. These inks contain silver nanocomposites and are applied on to unfired glazed ceramic bodies, yielding single-fired tiles. Silver nanocomposites were obtained from different precursors, which were made to react in order to obtain more stable structures that, in addition to incorporating bactericidal components, were able to reduce their reactivity and dissolution in the glassy matrix during the ceramic tile firing stage, avoiding the ensuing loss of properties. The study also examined how the nature of the base glaze affected the reactivity of the resulting nanocomposites. The base glaze that enabled the bactericidal compounds to remain at the ceramic tile surface was selected as the optimum base glaze for the study

    Selecting and implementing overview methods: implications from five exemplar overviews

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    This is the final version of the article. Available from BioMed Central via the DOI in this record.Background Overviews of systematic reviews are an increasingly popular method of evidence synthesis; there is a lack of clear guidance for completing overviews and a number of methodological challenges. At the UK Cochrane Symposium 2016, methodological challenges of five overviews were explored. Using data from these five overviews, practical implications to support methodological decision making of authors writing protocols for future overviews are proposed. Methods Methods, and their justification, from the five exemplar overviews were tabulated and compared with areas of debate identified within current literature. Key methodological challenges and implications for development of overview protocols were generated and synthesised into a list, discussed and refined until there was consensus. Results Methodological features of three Cochrane overviews, one overview of diagnostic test accuracy and one mixed methods overview have been summarised. Methods of selection of reviews and data extraction were similar. Either the AMSTAR or ROBIS tool was used to assess quality of included reviews. The GRADE approach was most commonly used to assess quality of evidence within the reviews. Eight key methodological challenges were identified from the exemplar overviews. There was good agreement between our findings and emerging areas of debate within a recent published synthesis. Implications for development of protocols for future overviews were identified. Conclusions Overviews are a relatively new methodological innovation, and there are currently substantial variations in the methodological approaches used within different overviews. There are considerable methodological challenges for which optimal solutions are not necessarily yet known. Lessons learnt from five exemplar overviews highlight a number of methodological decisions which may be beneficial to consider during the development of an overview protocol.The overview conducted by Pollock [19] was supported by a project grant from the Chief Scientist Office of the Scottish Government. The overview conducted by McClurg [21] was supported by a project grant by the Physiotherapy Research Foundation. The overview by Hunt [22] was supported as part of doctoral programme funding by the National Institute for Health Research (NIHR) Collaboration for Leadership in Applied Health Research and Care South West Peninsula (PenCLAHRC). The overview conducted by Estcourt [20] was supported by an NIHR Cochrane Programme Grant for the Safe and Appropriate Use of Blood Components. The overview conducted by Brunton [23] was commissioned by the Department of Health as part of an ongoing programme of work on health policy research synthesis. Alex Pollock is employed by the Nursing, Midwifery and Allied Health Professions (NMAHP) Research Unit, which is supported by the Chief Scientist Office of the Scottish Government. Pauline Campbell is supported by the Chief Nurses Office of the Scottish Government

    VLP-Based COVID-19 Vaccines: An Adaptable Technology against the Threat of New Variants.

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    Virus-like particles (VLPs) are a versatile, safe, and highly immunogenic vaccine platform. Recently, there are developmental vaccines targeting SARS-CoV-2, the causative agent of COVID-19. The COVID-19 pandemic affected humanity worldwide, bringing out incomputable human and financial losses. The race for better, more efficacious vaccines is happening almost simultaneously as the virus increasingly produces variants of concern (VOCs). The VOCs Alpha, Beta, Gamma, and Delta share common mutations mainly in the spike receptor-binding domain (RBD), demonstrating convergent evolution, associated with increased transmissibility and immune evasion. Thus, the identification and understanding of these mutations is crucial for the production of new, optimized vaccines. The use of a very flexible vaccine platform in COVID-19 vaccine development is an important feature that cannot be ignored. Incorporating the spike protein and its variations into VLP vaccines is a desirable strategy as the morphology and size of VLPs allows for better presentation of several different antigens. Furthermore, VLPs elicit robust humoral and cellular immune responses, which are safe, and have been studied not only against SARS-CoV-2 but against other coronaviruses as well. Here, we describe the recent advances and improvements in vaccine development using VLP technology

    The Special Functionalities of the Miltilevel Casceded H-Bridge Frequency Converters «ERATON-V»

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    В докладе представлена краткая информация о специализированных сервисных функциях выпускаемого ЗАО «ЭРАСИБ» г. Новосибирск многоуровневого преобразователя частоты типа «ЭРАТОН-В» с каскадным включением Н-мостов, который предназначен для работы в составе регулируемых электроприводов переменного тока среднего класса напряжений 3-10 кВ в диапазоне мощностей трехфазной электрической машины 1-10 МВт.The report is devoted to describe the special functionalities of multilevel frequency converter «ERATON-V» with series-connected H-bridge voltage-source inverter produced the industrial company «ERASIB», city Novosibirsk, which is untended for variable-speed AC three-phase drives rated at 3-10 kV and 1-10 MW

    The Harvey–Bradshaw Index adapted to a mobile application compared with In-clinic assessment: the MediCrohn Study

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    [Abstract] Objectives: Mobile apps are useful tools in e-health and self-management strategies in disease monitoring. We evaluated the Harvey–Bradshaw index (HBI) mobile app self-administered by the patient to see if its results agreed with HBI in-clinic assessed by a physician. Methods: Patients were enrolled in a 4-month prospective study with clinical assessments at months 1 and 4. Patients completed mobile app HBI and within 48 h, HBI was performed by a physician (gold standard). HBI scores characterized Crohn's disease (CD) as remission <5 or active ≥5. We determined agreement per item and total HBI score and intraclass correlation coefficients (ICCs). Bland–Altman plot was performed. HBI changes in disease activity from month 1 to month 4 were determined. Results: A total of 219 patients were enrolled. All scheduled assessments (385 pairs of the HBI questionnaire) showed a high percentage of agreement for remission/activity (92.4%, κ = 0.796), positive predictive value (PPV) for remission of 98.2%, and negative predictive value of 76.7%. High agreement was also found at month 1 (93.15%, κ = 0.82) and month 4 (91.5%, κ = 0.75). Bland–Altman plot was more uniform when the HBI mean values were <5 (remission). ICC values were 0.82, 0.897, and 0.879 in all scheduled assessments, 1 and 4 months, respectively. Conclusions: We found a high percentage of agreement between patients' self-administered mobile app HBI and in-clinic physician assessment to detect CD activity with a remarkably high PPV for remission. The mobile app HBI might allow a strict control of inflammation by remote monitoring and flexible follow-up of CD patients. Reduction of sanitary costs could be possible

    Disease severity in familial cases of IBD

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    Background: Phenotypic traits of familial IBD relative to sporadic cases are controversial, probably related to limited statistical power of published evidence. Aim: To know if there are phenotype differences between familial and sporadic IBD, evaluating the prospective Spanish registry (ENEIDA) with 11,983 cases. Methods: 5783 patients (48.3%) had ulcerative colitis (UC) and 6200 (51.7%) Crohn's disease (CD). Cases with one or more 1st, 2nd or 3rd degree relatives affected by UC/CD were defined as familial case. Results: In UC and CD, familial cases compared with sporadic cases had an earlier disease onset (UC: 33 years [IQR 25–44] vs 37 years [IQR 27–49]; p b 0.0001); (CD: 27 years [IQR 21–35] vs 29 years [IQR 22–40]; p b 0.0001), higher prevalence of extraintestinal immune-related manifestations (EIMs) (UC: 17.2% vs 14%; p = 0.04); (CD: 30.1% vs 23.6%; p b 0.0001). Familial CD had higher percentage of ileocolic location (42.7% vs 51.8%; p = 0.0001), penetrating behavior (21% vs 17.6%; p = 0.01) and perianal disease (32% vs 27.1%; p = 0.003). Differences are not influenced by degree of consanguinity. Conclusion: When a sufficiently powered cohort is evaluated, familial aggregation in IBD is associated to an earlier disease onset, more EIMs and more severe phenotype in CD. This feature should be taken into account at establishing predictors of disease course

    El registro ENEIDA (Estudio Nacional en Enfermedad Inflamatoria intestinal sobre Determinantes genéticos y Ambientales) de GETECCU: diseño, monitorización y funciones

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    El registro ENEIDA, promovido por el Grupo Español de Trabajo en Enfermedad de Crohn y Colitis Ulcerosa (GETECCU), fue creado en 2005 por un grupo de gastroenterólogos interesados en mejorar el manejo de los pacientes con enfermedad inflamatoria intestinal. Los objetivos principales del registro fueron facilitar la recogida de datos clínicos de interés para la práctica clínica asistencial, así como la elaboración de estudios colaborativos a partir de datos clínicos y muestras biológicas. En sus 15 años de existencia, ENEIDA ha evolucionado en múltiples aspectos, desde su contenido o su soporte tecnológico hasta el número de centros participantes, para convertirse en uno de los registros de referencia para el estudio y cuidado de los pacientes con enfermedad inflamatoria intestinal, con una producción científica continua y de alta calidad que lo ha situado como ejemplo de explotación científica colaborativa en el ámbito internacional. En este artículo se revisan los objetivos, el diseño, las características estructurales, la monitorización y la explotación científica del registro ENEIDA

    Interferon β-1a in relapsing multiple sclerosis: four-year extension of the European IFNβ-1a Dose-C omparison Study

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    Background: Multiple sclerosis (MS) is a chronic disease requiring long-term monitoring of treatment. Objective: To assess the four-year clinical efficacy of intramuscular (IM) IFNb-1a in patients with relapsing MS from the European IFNb-1a Dose-C omparison Study. Methods: Patients who completed 36 months of treatment (Part 1) of the European IFNb-1a Dose-C omparison Study were given the option to continue double-blind treatment with IFNb-1a 30 mcg or 60 mcg IM once weekly (Part 2). Analyses of 48-month data were performed on sustained disability progression, relapses, and neutralizing antibody (NA b) formation. Results: O f 608/802 subjects who completed 36 months of treatment, 493 subjects continued treatment and 446 completed 48 months of treatment and follow-up. IFNb-1a 30 mcg and 60 mcg IM once weekly were equally effective for up to 48 months. There were no significant differences between doses over 48 months on any of the clinical endpoints, including rate of disability progression, cumulative percentage of patients who progressed (48 and 43, respectively), and annual relapse rates; relapses tended to decrease over 48 months. The incidence of patients who were positive for NAbs at any time during the study was low in both treatment groups. Conclusion: C ompared with 60-mcg IM IFNb-1a once weekly, a dose of 30 mcg IM IFNb-1a once weekly maintains the same clinical efficacy over four years
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