65 research outputs found

    Numerical Flow Analysis of the GAMM Turbine at nominal and off-design Operating Conditions

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    The flow in a Francis turbine runner (GAMM Turbine) is analysed numerically. Different operating points are calculated using two industrial software packages based respectively on a finite element method (N3S) and a finite volume method (TASCflow®) and compared to experimental results. The numerical results allow to observe physical phenomena in the runner that are important in the process of hydraulic turbomachinery design. Values of Cu and Cm velocity components, blade pressure distribution and recirculation in the flow are compared to experimental results at nominal and off-design flow conditions. The experimental and numerical results show a similar efficiency evolution in function of flow rate and head, however the absolute level of energetic losses are overestimated by the two numerical codes

    Generation of three induced pluripotent stem cell lines (UQACi003-A, UQACi004-A, and UQACi006-A) from three patients with KRT5 epidermolysis bullosa simplex mutations

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    Heterozygous mutations within Keratin 5 (KRT5) are common genetic causes of epidermolysis bullosa simplex (EBS), a skin fragility disorder characterized by blisters, which appear after minor trauma. Using CytoTune®Sendai virus, we generated three human induced pluripotent stem cell (iPSC) lines from three EBS patients carrying respectively the single heterozygous mutations in KRT5, c.449 T > C, c.980 T > C, and c.608 T > C. All lines display normal karyotype, expressed high levels of pluripotent markers, and can differentiate into derivatives of the three germ layers. These iPSCs are helpful for a better understanding of the EBS pathogenesis and developing novel therapeutic approaches

    Generation of two induced pluripotent stem cell lines (UQACi002-A and UQACi005-A) from two patients with KRT14 epidermolysis bullosa simplex mutations

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    More than 107 pathogenic variations were identified in Keratin 14 gene (KRT14) in patients affected by epidermolysis bullosa simplex (EBS), a rare skin disease with still no curative treatment. Disease models as human induced pluripotent stem cells (hiPSCs) are promising tool for further advance the knowledge about this disorder and accelerate therapies development. Here, two hiPSC lines were reprogrammed from skin fibroblasts of two EBS patients carrying mutations within KRT14 by using CytoTune®Sendai virus. These iPSCs display pluripotent cell morphology, pluripotent markers expression, and the capability to differentiate into the three germ layers

    Sequence variant (CTAGGG)n in the human telomere favors a G-quadruplex structure containing a G·C·G·C tetrad

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    Short contiguous arrays of variant CTAGGG repeats in the human telomere are unstable in the male germline and somatic cells, suggesting formation of unusual structures by this repeat type. Here, we report on the structure of an intramolecular G-quadruplex formed by DNA sequences containing four human telomeric variant CTAGGG repeats in potassium solution. Our results reveal a new robust antiparallel G-quadruplex fold involving two G-tetrads sandwiched between a G·C base pair and a G·C·G·C tetrad, which could represent a new platform for drug design targeted to human telomeric DNA

    The Biobanque québécoise de la COVID-19 (BQC19)—A cohort to prospectively study the clinical and biological determinants of COVID-19 clinical trajectories

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    SARS-CoV-2 infection causing the novel coronavirus disease 2019 (COVID–19) has been responsible for more than 2.8 million deaths and nearly 125 million infections worldwide as of March 2021. In March 2020, the World Health Organization determined that the COVID–19 outbreak is a global pandemic. The urgency and magnitude of this pandemic demanded immediate action and coordination between local, regional, national, and international actors. In that mission, researchers require access to high-quality biological materials and data from SARS-CoV-2 infected and uninfected patients, covering the spectrum of disease manifestations. The “Biobanque québécoise de la COVID-19” (BQC19) is a pan–provincial initiative undertaken in Québec, Canada to enable the collection, storage and sharing of samples and data related to the COVID-19 crisis. As a disease-oriented biobank based on high-quality biosamples and clinical data of hospitalized and non-hospitalized SARS-CoV-2 PCR positive and negative individuals. The BQC19 follows a legal and ethical management framework approved by local health authorities. The biosamples include plasma, serum, peripheral blood mononuclear cells and DNA and RNA isolated from whole blood. In addition to the clinical variables, BQC19 will provide in-depth analytical data derived from the biosamples including whole genome and transcriptome sequencing, proteome and metabolome analyses, multiplex measurements of key circulating markers as well as anti-SARS-CoV-2 antibody responses. BQC19 will provide the scientific and medical communities access to data and samples to better understand, manage and ultimately limit, the impact of COVID-19. In this paper we present BQC19, describe the process according to which it is governed and organized, and address opportunities for future research collaborations. BQC19 aims to be a part of a global communal effort addressing the challenges of COVID–19

    The Athena X-ray Integral Field Unit: a consolidated design for the system requirement review of the preliminary definition phase

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    The Athena X-ray Integral Unit (X-IFU) is the high resolution X-ray spectrometer studied since 2015 for flying in the mid-30s on the Athena space X-ray Observatory. Athena is a versatile observatory designed to address the Hot and Energetic Universe science theme, as selected in November 2013 by the Survey Science Committee. Based on a large format array of Transition Edge Sensors (TES), X-IFU aims to provide spatially resolved X-ray spectroscopy, with a spectral resolution of 2.5 eV (up to 7 keV) over a hexagonal field of view of 5 arc minutes (equivalent diameter). The X-IFU entered its System Requirement Review (SRR) in June 2022, at about the same time when ESA called for an overall X-IFU redesign (including the X-IFU cryostat and the cooling chain), due to an unanticipated cost overrun of Athena. In this paper, after illustrating the breakthrough capabilities of the X-IFU, we describe the instrument as presented at its SRR (i.e. in the course of its preliminary definition phase, so-called B1), browsing through all the subsystems and associated requirements. We then show the instrument budgets, with a particular emphasis on the anticipated budgets of some of its key performance parameters, such as the instrument efficiency, spectral resolution, energy scale knowledge, count rate capability, non X-ray background and target of opportunity efficiency. Finally, we briefly discuss the ongoing key technology demonstration activities, the calibration and the activities foreseen in the X-IFU Instrument Science Center, touch on communication and outreach activities, the consortium organisation and the life cycle assessment of X-IFU aiming at minimising the environmental footprint, associated with the development of the instrument. Thanks to the studies conducted so far on X-IFU, it is expected that along the design-to-cost exercise requested by ESA, the X-IFU will maintain flagship capabilities in spatially resolved high resolution X-ray spectroscopy, enabling most of the original X-IFU related scientific objectives of the Athena mission to be retained. The X-IFU will be provided by an international consortium led by France, The Netherlands and Italy, with ESA member state contributions from Belgium, Czech Republic, Finland, Germany, Poland, Spain, Switzerland, with additional contributions from the United States and Japan.The French contribution to X-IFU is funded by CNES, CNRS and CEA. This work has been also supported by ASI (Italian Space Agency) through the Contract 2019-27-HH.0, and by the ESA (European Space Agency) Core Technology Program (CTP) Contract No. 4000114932/15/NL/BW and the AREMBES - ESA CTP No.4000116655/16/NL/BW. This publication is part of grant RTI2018-096686-B-C21 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe”. This publication is part of grant RTI2018-096686-B-C21 and PID2020-115325GB-C31 funded by MCIN/AEI/10.13039/501100011033

    The Athena X-ray Integral Field Unit: a consolidated design for the system requirement review of the preliminary definition phase

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    The Athena X-ray Integral Unit (X-IFU) is the high resolution X-ray spectrometer, studied since 2015 for flying in the mid-30s on the Athena space X-ray Observatory, a versatile observatory designed to address the Hot and Energetic Universe science theme, selected in November 2013 by the Survey Science Committee. Based on a large format array of Transition Edge Sensors (TES), it aims to provide spatially resolved X-ray spectroscopy, with a spectral resolution of 2.5 eV (up to 7 keV) over an hexagonal field of view of 5 arc minutes (equivalent diameter). The X-IFU entered its System Requirement Review (SRR) in June 2022, at about the same time when ESA called for an overall X-IFU redesign (including the X-IFU cryostat and the cooling chain), due to an unanticipated cost overrun of Athena. In this paper, after illustrating the breakthrough capabilities of the X-IFU, we describe the instrument as presented at its SRR, browsing through all the subsystems and associated requirements. We then show the instrument budgets, with a particular emphasis on the anticipated budgets of some of its key performance parameters. Finally we briefly discuss on the ongoing key technology demonstration activities, the calibration and the activities foreseen in the X-IFU Instrument Science Center, and touch on communication and outreach activities, the consortium organisation, and finally on the life cycle assessment of X-IFU aiming at minimising the environmental footprint, associated with the development of the instrument. Thanks to the studies conducted so far on X-IFU, it is expected that along the design-to-cost exercise requested by ESA, the X-IFU will maintain flagship capabilities in spatially resolved high resolution X-ray spectroscopy, enabling most of the original X-IFU related scientific objectives of the Athena mission to be retained. (abridged).Comment: 48 pages, 29 figures, Accepted for publication in Experimental Astronomy with minor editin

    Extracorporeal Membrane Oxygenation for Severe Acute Respiratory Distress Syndrome associated with COVID-19: An Emulated Target Trial Analysis.

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    RATIONALE: Whether COVID patients may benefit from extracorporeal membrane oxygenation (ECMO) compared with conventional invasive mechanical ventilation (IMV) remains unknown. OBJECTIVES: To estimate the effect of ECMO on 90-Day mortality vs IMV only Methods: Among 4,244 critically ill adult patients with COVID-19 included in a multicenter cohort study, we emulated a target trial comparing the treatment strategies of initiating ECMO vs. no ECMO within 7 days of IMV in patients with severe acute respiratory distress syndrome (PaO2/FiO2 <80 or PaCO2 ≥60 mmHg). We controlled for confounding using a multivariable Cox model based on predefined variables. MAIN RESULTS: 1,235 patients met the full eligibility criteria for the emulated trial, among whom 164 patients initiated ECMO. The ECMO strategy had a higher survival probability at Day-7 from the onset of eligibility criteria (87% vs 83%, risk difference: 4%, 95% CI 0;9%) which decreased during follow-up (survival at Day-90: 63% vs 65%, risk difference: -2%, 95% CI -10;5%). However, ECMO was associated with higher survival when performed in high-volume ECMO centers or in regions where a specific ECMO network organization was set up to handle high demand, and when initiated within the first 4 days of MV and in profoundly hypoxemic patients. CONCLUSIONS: In an emulated trial based on a nationwide COVID-19 cohort, we found differential survival over time of an ECMO compared with a no-ECMO strategy. However, ECMO was consistently associated with better outcomes when performed in high-volume centers and in regions with ECMO capacities specifically organized to handle high demand. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/)

    Genetics of familial and sporadic amyotrophic lateral sclerosis

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    Diseases affecting motor neurons, such as amyotrophic lateral sclerosis (Lou Gerhig's disease), hereditary spastic paraplegia and spinal bulbar muscular atrophy (Kennedy's disease) form a heterogeneous group of chronic progressive diseases and are among the most puzzling yet untreatable illnesses. Over the last decade identification of mutations in genes predisposing to these disorders has provided the means to better understand their pathogenesis. The discovery 13 years ago of SOD1 mutations linked to ALS, which account for less than 2% of all cases, had a major impact in the field. However, despite intensive research effort, the pathways leading to the specific motor neurons degeneration in the presence of SOD1 mutations have not been fully identified. The research projects presented here aim to investigate the role of different cell types and tissues in the pathology of SOD1-linked ALS, and to identify new genetic factors involved in sporadic ALS cases. LoxP transgenic mice expressing mutated G85R SOD1, allowing transgene expression in cell and tissue specific manner, have been successfully generated. However, mice, up to 2.5 years of age, did not develop any motor neuron deficits or any developmental abnormalities. We concluded that this might be due to insufficient level of the transgene expression in our transgenic animals. Also, a number of candidate genes for ALS have been identified, such as ALS2, VEGF, PRPH, CHGA and CHGB, based on their pattern of expression and biological function. These genes have been screened for mutations in a cohort of ALS patients and, we have identified one basepair deletion in the ALS2 and in the PRPH genes, and we have also found a strong genetic association between the CHGA and CHGB genes with ALS. An in-vitro cell transfection approach has been used to investigate the biological effects of mutations within the PRPH genes and, of particular interest, this technique has revealed the first functional variants in a neurofilament associated gene ever describe in ALS
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