112 research outputs found

    Some inverse source problems of determining a space dependent source in fractional-dual-phase-lag type equations

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    The dual-phase-lag heat transfer models attract a lot of interest of researchers in the last few decades. These are used in problems arising from non-classical thermal models, which are based on a non-Fourier type law. We study uniqueness of solutions to some inverse source problems for fractional partial differential equations of the Dual-Phase-Lag type. The source term is supposed to be of the formh(t)f(x)with a known functionh(t). The unknown space dependent sourcef(x)is determined from the final time observation. New uniqueness results are formulated in Theorem 1 (for a general fractional Jeffrey-type model). Here, the variational approach was used. Theorem 2 derives uniqueness results under weaker assumptions onh(t)(monotonically increasing character ofh(t)was removed) in a case ofdominant parabolicbehavior. The proof technique was based on spectral analysis. Section Modified Model for tau q>tau Tshows that an analogy of Theorem 2 fordominant hyperbolicbehavior (fractional Cattaneo-Vernotte equation) is not possible

    Existence and uniqueness of a weak solution to fractional single-phase-lag heat equation

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    In this article, we study the existence and uniqueness of a weak solution to the fractional single-phase lag heat equation. This model contains the terms DtĪ±(ut)\cal{D}_t^\alpha(u_t) and DtĪ±u\cal{D}_t^\alpha u (with Ī±āˆˆ(0,1)\alpha \in(0,1)), where DtĪ±\cal{D}_t^\alpha denotes the Caputo fractional derivative in time of constant order Ī±āˆˆ(0,1)\alpha\in(0,1). We consider homogeneous Dirichlet boundary data for the temperature. We rigorously show the existence of a unique weak solution under low regularity assumptions on the data. Our main strategy is to use the variational formulation and a semidiscretisation in time based on Rothe's method. We obtain a priori estimates on the discrete solutions and show convergence of the Rothe functions to a weak solution. The variational approach is employed to show the uniqueness of this weak solution to the problem. We also consider the one-dimensional problem and derive a representation formula for the solution. We establish bounds on this explicit solution and its time derivative by extending properties of the multinomial Mittag-Leffler function.Comment: 27 page

    HalƔsz's theorem for Beurling generalized numbers

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    We show that HalĆ”szā€™s theorem holds for Beurling numbers under the following two mild hypotheses on the generalized number system: existence of a positive density for the generalized integers and a Chebyshev upper bound for the generalized primes

    Sargramostim to treat patients with acute hypoxic respiratory failure due to COVID-19 (SARPAC) : a structured summary of a study protocol for a randomised controlled trial

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    ObjectivesThe hypothesis of the proposed intervention is that Granulocyte-macrophage colony-stimulating factor (GM-CSF) has profound effects on antiviral immunity, and can provide the stimulus to restore immune homeostasis in the lung with acute lung injury post COVID-19, and can promote lung repair mechanisms, that lead to a 25% improvement in lung oxygenation parameters. Sargramostim is a man-made form of the naturally-occurring protein GM-CSF.Trial designA phase 4 academic, prospective, 2 arm (1:1 ratio), randomized, open-label, controlled trial.ParticipantsPatients aged 18-80 years admitted to specialized COVID-19 wards in 5 Belgian hospitals with recent ( 20 mg methylprednisolone or equivalent), (6) enrolment in another investigational study, (7) pregnant or breastfeeding or (8) ferritin levels > 2000 mu g/mL.Intervention and comparatorInhaled sargramostim 125 mu g twice daily for 5 days in addition to standard care. Upon progression of disease requiring mechanical ventilation or to acute respiratory distress syndrome (ARDS) and initiation of mechanical ventilator support within the 5 day period, inhaled sargramostim will be replaced by intravenous sargramostim 125 mu g/m(2) body surface area once daily until the 5 day period is reached. From day 6 onwards, progressive patients in the active group will have the option to receive an additional 5 days of IV sargramostim, based on the treating physician's assessment. Intervention will be compared to standard of care. Subjects progressing to ARDS and requiring invasive mechanical ventilatory support, from day 6 onwards in the standard of care group will have the option (clinician's decision) to initiate IV sargramostim 125m mu g/m(2) body surface area once daily for 5 days.Main outcomesThe primary endpoint of this intervention is measuring oxygenation after 5 days of inhaled (and intravenous) treatment through assessment of a change in pretreatment and post-treatment ratio of PaO2/FiO(2) and through measurement of the P(A-a)O-2 gradient (PAO(2)= Partial alveolar pressure of oxygen, PaO2=Partial arterial pressure of oxygen; FiO(2)= Fraction of inspired oxygen).RandomisationPatients will be randomized in a 1:1 ratio. Randomization will be done using REDCap (electronic IWRS system).Blinding (masking)In this open-label trial neither participants, caregivers, nor those assessing the outcomes will be blinded to group assignment.Numbers to be randomised (sample size)A total of 80 patients with confirmed COVID-19 and acute hypoxic respiratory failure will be enrolled, 40 in the active and 40 in the control group.Trial StatusSARPAC protocol Version 2.0 (April 15 2020). Participant recruitment is ongoing in 5 Belgian Hospitals (i.e. University Hospital Ghent, AZ Sint-Jan Bruges, AZ Delta Roeselare, University Hospital Brussels and ZNA Middelheim Antwerp). Participant recruitment started on March 26(th) 2020. Given the current decline of the COVID-19 pandemic in Belgium, it is difficult to anticipate the rate of participant recruitment.Trial registrationThe trial was registered on Clinical Trials.gov on March 30(th), 2020 (ClinicalTrials.gov Identifier: NCT04326920) - retrospectively registered; https://clinicaltrials.gov/ct2/show/NCT04326920?term=sarpac&recrs=ab&draw=2&rank=1 and on EudraCT on March 24th, 2020 (Identifier: 2020-001254-22).Full protocolThe full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol

    Treatment of severely ill COVID-19 patients with anti-interleukin drugs (COV-AID) : a structured summary of a study protocol for a randomised controlled trial

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    ObjectivesThe purpose of this study is to test the safety and effectiveness of individually or simultaneously blocking IL-6, IL-6 receptor and IL-1 versus standard of care on blood oxygenation and systemic cytokine release syndrome in patients with COVID-19 coronavirus infection and acute hypoxic respiratory failure and systemic cytokine release syndrome.Trial designA phase 3 prospective, multi-center, interventional, open label, 6-arm 2x2 factorial design study.ParticipantsSubjects will be recruited at the specialized COVID-19 wards and/or ICUs at 16 Belgian participating hospitals. Only adult (>= 18y old) patients will be recruited with recent (<= 16 days) COVID-19 infection and acute hypoxia (defined as PaO2/FiO2 below 350mmHg or PaO2/FiO2 below 280 on supplemental oxygen and immediately requiring high flow oxygen device or mechanical ventilation) and signs of systemic cytokine release syndrome characterized by high serum ferritin, or high D-dimers, or high LDH or deep lymphopenia or a combination of those, who have not been on mechanical ventilation for more than 24 hours before randomisation. Patients should have had a chest X-ray and/or CT scan showing bilateral infiltrates within the last 2 days before randomisation. Patients with active bacterial or fungal infection will be excluded.Intervention and comparatorPatients will be randomized to 1 of 5 experimental arms versus usual care. The experimental arms consist of Anakinra alone (anti-IL-1 binding the IL-1 receptor), Siltuximab alone (anti-IL-6 chimeric antibody), a combination of Siltuximab and Anakinra, Tocilizumab alone (humanised anti-IL-6 receptor antibody) or a combination of Anakinra with Tocilizumab in addition to standard care. Patients treated with Anakinra will receive a daily subcutaneous injection of 100mg for a maximum of 28 days or until hospital discharge, whichever comes first. Siltuximab (11mg/kg) or Tocilizumab (8mg/kg, with a maximum dose of 800mg) are administered as a single intravenous injection immediately after randomization.Main outcomesThe primary end point is the time to clinical improvement defined as the time from randomization to either an improvement of two points on a six-category ordinal scale measured daily till day 28 or discharge from the hospital or death. This ordinal scale is composed of (1) Death; (2) Hospitalized, on invasive mechanical ventilation or ECMO; (3) Hospitalized, on non-invasive ventilation or high flow oxygen devices; (4) Hospitalized, requiring supplemental oxygen; (5) Hospitalized, not requiring supplemental oxygen; (6) Not hospitalized.RandomisationPatients will be randomized using an Interactive Web Response System (REDCap). A 2x2 factorial design was selected with a 2:1 randomization regarding the IL-1 blockade (Anakinra) and a 1:2 randomization regarding the IL-6 blockade (Siltuximab and Tocilizumab).Blinding (masking)In this open-label trial neither participants, caregivers, nor those assessing the outcomes are blinded to group assignment.Numbers to be randomised (sample size)A total of 342 participants will be enrolled: 76 patients will receive usual care, 76 patients will receive Siltuximab alone, 76 patients will receive Tocilizumab alone, 38 will receive Anakinra alone, 38 patients will receive Anakinra and Siltuximab and 38 patients will receive Anakinra and Tocilizumab.Trial StatusCOV-AID protocol version 3.0 (15 Apr 2020). Participant recruitment is ongoing and started on April 4(th) 2020. Given the current decline of the COVID-19 pandemic in Belgium, it is difficult to anticipate the rate of participant recruitment.Trial registrationThe trial was registered on Clinical Trials.gov on April 1st, 2020 (ClinicalTrials.gov Identifier: NCT04330638) and on EudraCT on April 3rd 2020 (Identifier: 2020-001500-41).Full protocolThe full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol

    In vitro functional quality characterization of NOTA-modified somatropins

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    Chemical modifications on protein biopharmaceuticals introduce extra variability in addition to their inherent complexity, hence require more comprehensive analytical and functional characterization during their discovery, development, and manufacturing. Somatropin (i.e., recombinant human growth hormone, rhGH) modified with the chelating agent S-2-(4-isothiocyanatobenzyl)-1,4,7-triazacyclononane-1,4,7-triacetic acid (p-SCN-Bn-NOTA) allows the incorporation of radiometals for research and possible theranostic purposes. We previously demonstrated that this conjugation leads to multiple substitution degrees and positional isomers within the product. In vitro techniques at the molecular and cellular levels were now applied to assess their functional quality: (i) size exclusion chromatography (SEC) demonstrated functional complexation with human growth hormone binding protein (hGHBp) to the different NOTA-modified somatropins as well as to gallium chelated NOTA-functionalities (Ga-10:1 NOTA-somatropin); (ii) native mass spectrometry (MS) offered in-depth information, a substitution degree up to four NOTAs was still functional; (iii) circular dichroism (CD) analysis confirmed the complexation of unmodified and NOTA-modified somatropin to hGHBp; and (iv) a hGHR bioassay demonstrated initiation of the signal transduction cascade, after binding of all investigated products to the receptor presented on cells with a similar potency (pEC50 values between 9.53 and 9.78) and efficacy (Emax values between 130 and 160%). We conclude that the NOTA-modified somatropins do not possess a significantly different in vitro functionality profile compared to unmodified somatropin. Techniques such as SEC, MS, and CD, traditionally used in the physicochemical characterization of proteins have a demonstrated potential use in the functionality evaluation not only in drug discovery and development but also in quality control settings.Grants from the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT-Vlaanderen) to B.G. (Grant 121512) and F.V. (Grant 131356), and the PhD research grants from China Scholarship Council (CSC) to H.Y. and X.X.http://pubs.acs.org/loi/ancham2018-03-07hj2017Nuclear Medicin

    A 220-nucleotide deletion of the intronic enhancer reveals an epigenetic hierarchy in immunoglobulin heavy chain locus activation

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    A tissue-specific transcriptional enhancer, EĪ¼, has been implicated in developmentally regulated recombination and transcription of the immunoglobulin heavy chain (IgH) gene locus. We demonstrate that deleting 220 nucleotides that constitute the core EĪ¼ results in partially active locus, characterized by reduced histone acetylation, chromatin remodeling, transcription, and recombination, whereas other hallmarks of tissue-specific locus activation, such as loss of H3K9 dimethylation or gain of H3K4 dimethylation, are less affected. These observations define EĪ¼-independent and EĪ¼-dependent phases of locus activation that reveal an unappreciated epigenetic hierarchy in tissue-specific gene expression

    Alignment of the CMS tracker with LHC and cosmic ray data

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    Ā© CERN 2014 for the benefit of the CMS collaboration, published under the terms of the Creative Commons Attribution 3.0 License by IOP Publishing Ltd and Sissa Medialab srl. Any further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation and DOI.The central component of the CMS detector is the largest silicon tracker ever built. The precise alignment of this complex device is a formidable challenge, and only achievable with a significant extension of the technologies routinely used for tracking detectors in the past. This article describes the full-scale alignment procedure as it is used during LHC operations. Among the specific features of the method are the simultaneous determination of up to 200 000 alignment parameters with tracks, the measurement of individual sensor curvature parameters, the control of systematic misalignment effects, and the implementation of the whole procedure in a multi-processor environment for high execution speed. Overall, the achieved statistical accuracy on the module alignment is found to be significantly better than 10Ī¼m
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