The ALTO project at IPN Orsay

In order to probe neutron rich radioactive noble gases produced by photo-fission, a PARRNe1 experiment (Production d'Atomes Radioactifs Riches en Neutrons) has been carried out at CERN. The incident electron beam of 50 MeV was delivered by the LIL machine: LEP Injector Linac. The experiment allowed to compare under the same conditions two production methods of radioactive noble gases: fission induced by fast neutrons and photo-fission. The obtained results show that the use of the electrons is a promising mode to get intense neutron rich ion beams. Thereafter, the success of this photo-fission experiment, a conceptual design for the installation at IPN Orsay of a 50 MeV electron accelerator close to the PARRNe-2 device has been worked out: ALTO Project. This work has started within a collaboration between IPNO, LAL and CERN groups.Comment: 14 pages, pdf file, International School-Seminar on Heavy-Ion Physics 7 (2002

In vivo biotinylated calpastatin improves the affinity purification of human m-calpain

Recently we established a novel affinity purification method for calpain by exploiting the specific and reversible binding properties of its intrinsically disordered protein inhibitor, calpastatin. The immobilization strategy relied on the strength and specificity of the biotin - streptavidin interaction. Here, we report an improved and optimized method that even enables the general applicability of in vivo biotinylated (intrinsically disordered) proteins in any affinity capture strategy. Since in vitro chemical biotinylation is only accomplished with reagents that lack exact site specificity, it can not only cause sample heterogeneity but it can also hamper the functionality of the biotinylated molecules. Therefore, we have developed a recombinant expression protocol to produce in vivo biotinylated human calpastatin domain 1 (hCSD1) in Escherichia coli. We have experimentally verified that the biotinylated polypeptide tag is compatible with the intrinsically disordered state of hCSD1 and that it does not influence the functional properties of this intrinsically disordered protein (IDP). The in vivo biotinylated hCSD1 was then used without the need of any prepurification step prior to the affinity capturing of its substrate, human m-calpain. This leads to a simplified purification strategy that allows capturing the calpain efficiently from a complex biological mixture with only a single chromatogaphic step and in a considerably reduced timeframe. Our approach is generally applicable through the in vivo biotinylation of any IDP of interest, and its practical implementation will showcase the power to exploit the properties of IDPs in affinity capture strategies. © 2018 The Author

Specific Migratory Dendritic Cells Rapidly Transport Antigen from the Airways to the Thoracic Lymph Nodes

Antigen transport from the airway mucosa to the thoracic lymph nodes (TLNs) was studied in vivo by intratracheal instillation of fluorescein isothiocyanate (FITC)-conjugated macromolecules. After instillation, FITC+ cells with stellate morphology were found deep in the TLN T cell area. Using flow cytometry, an FITC signal was exclusively detected in CD11cmed-hi/major histocompatibility complex class II (MHCII)hi cells, representing migratory airway-derived lymph node dendritic cells (AW-LNDCs). No FITC signal accumulated in lymphocytes and in a CD11chiMHCIImed DC group containing a CD8αhi subset (non–airway-derived [NAW]-LNDCs). Sorted AW-LNDCs showed long MHCIIbright cytoplasmic processes and intracytoplasmatic FITC+ granules. The fraction of FITC+ AW-LNDCs peaked after 24 h and had reached baseline by day 7. AW-LNDCs were depleted by 7 d of ganciclovir treatment in thymidine kinase transgenic mice, resulting in a strong reduction of FITC-macromolecule transport into the TLNs. Compared with intrapulmonary DCs, AW-LNDCs had a mature phenotype and upregulated levels of MHCII, B7-2, CD40, and intracellular adhesion molecule (ICAM)-1. In addition, sorted AW-LNDCs from FITC-ovalbumin (OVA)–instilled animals strongly presented OVA to OVA-TCR transgenic T cells. These results validate the unique sentinel role of airway DCs, picking up antigen in the airways and delivering it in an immunogenic form to the T cells in the TLNs

In-gas-cell laser ionization spectroscopy in the vicinity of 100Sn: Magnetic moments and mean-square charge radii of N=50-54 Ag

In-gas-cell laser ionization spectroscopy studies on the neutron deficient 97-101Ag isotopes have been performed with the LISOL setup. Magnetic dipole moments and mean-square charge radii have been determined for the first time with the exception of 101Ag, which was found in good agreement with previous experimental values. The reported results allow tentatively assigning the spin of 97,99Ag to 9/2 and confirming the presence of an isomeric state in these two isotopes, whose collapsed hyperfine structure suggests a spin of 1/2 . The effect of the N=50 shell closure is not only manifested in the magnetic moments but also in the evolution of the mean-square charge radii of the isotopes investigated, in accordance with the spherical droplet model predictions

Using longitudinal antibiotic point prevalence survey (PPS) to drive antimicrobial stewardship programmes in a Nigerian tertiary hospital

Background: Antimicrobial stewardship (AMS) provides a means of tackling antimicrobial resistance (AMR). Unfortunately, in Nigeria, like in some other low-and-middle-income countries (LMICs), AMS practice has been lacklustre due to poor institutional support amongst other factors. Efforts were made to address this situation by engaging with the management of National Hospital Abuja, Nigeria, using antibiotic prescription information obtained through repeated point prevalence survey.Methodology: Two rounds of antibiotic PPS were conducted in 2015 and 2017 using the Global Point Prevalence Survey (G-PPS) format. Data were collected from all inpatients receiving antibiotics on the selected day of study, including patient characteristics, antimicrobial prescription details, laboratory results and information on a set of quality indicators. The data were uploaded to an online G-PPS application hosted at the University of Antwerp in Belgium for validation, analysis and reporting.Results: The PPS data showed that hospital-wide antibiotic use prevalence increased from 58% in 2015 to 61% in 2017. Surgical prophylaxis beyond 24 hours also increased from 88-90% in 2015 to 100% in 2017, and only minority of therapies were supported by laboratory input for diagnosis and monitoring; 22% in 2015 and 5% in 2017.Conclusion: These results were used for evidence-based engagement with the management to formally support AMS activities in the hospital. Positive outcomes were the formal reconstitution and inauguration of AMS committee in 2018 as well as the issuance of a formal policy statement by the hospital in 2020. The ease and free availability of Global PPS methodology makes it ideal in driving antimicrobial stewardship programme (ASP) in LMICs like Nigeria. Keywords: Antibiotic stewardship checklist, institutional support, point   French Title: Utilisation d'une enquête longitudinale sur la prévalence ponctuelle des antibiotiques (PPS) pour conduire des programmes de gestion des antimicrobiens dans un hôpital tertiaire nigérian Contexte: La gestion des antimicrobiens (AMS) offre un moyen de lutter contre la résistance aux antimicrobiens (RAM). Malheureusement, au Nigéria, comme dans certains autres pays à revenu faible ou intermédiaire (PRFI), la pratique de la MGS a été médiocre en raison d'un soutien institutionnel insuffisant, entre autres facteurs. Des  Longitudinal PPS for AMS programmes efforts ont été faits pour remédier à cette situation en collaborant avec la direction de l'hôpital national d'Abuja, au Nigéria, en utilisant les informations sur les prescriptions d'antibiotiques obtenues grâce à une enquête ponctuelle répétée de prévalence.Méthodologie: Deux séries d'antibiotiques PPS ont été menées en 2015 et 2017 en utilisant le format Global Point Prevalence Survey (G-PPS). Des données ont été recueillies auprès de tous les patients hospitalisés recevant des antibiotiques le jour sélectionné de l'étude, y compris les caractéristiques des patients, les détails de la prescription d'antimicrobiens, les résultats de laboratoire et les informations sur un ensemble d'indicateurs de qualité. Les données ont été téléchargées sur une application en ligne G-PPS hébergée à l'Université d'Anvers en Belgique à des fins de validation, d'analyse et rapports.Résultats: Les données PPS ont montré que la prévalence de l'utilisation d'antibiotiques à l'échelle de l'hôpital est passée de 58% en 2015 à 61% en 2017. La prophylaxie chirurgicale au-delà de 24 heures est également passée de 88 à 90% en 2015 à 100% en 2017, et seule une minorité de thérapies a été soutenue par entrée de laboratoire pour le diagnostic et la surveillance; 22% en 2015 et 5% en 2017.Conclusion: Ces résultats ont été utilisés pour un engagement fondé sur des données probantes avec la direction afin de soutenir officiellement les activités AMS à l'hôpital. Les résultats positifs ont été la reconstitution formelle et l'inauguration du comité AMS en 2018 ainsi que la publication d'une déclaration de politique formelle par l'hôpital en 2020. La facilité et la disponibilité gratuite de la méthodologie Global PPS la rend idéale pour conduire le programme de gestion des antimicrobiens (ASP) en PRFI comme le Nigéria. Mots clés: liste de contrôle pour la gestion des antibiotiques, soutien institutionnel, enquête ponctuelle de prévalence, déclaration de politique prevalence survey, policy statement &nbsp

Shape Isomerism at N = 40: Discovery of a Proton Intruder in 67Co

The nuclear structure of 67Co has been investigated through 67Fe beta-decay. The 67Fe isotopes were produced at the LISOL facility in proton-induced fission of 238U and selected using resonant laser ionization combined with mass separation. The application of a new correlation technique unambiguously revealed a 496(33) ms isomeric state in 67Co at an unexpected low energy of 492 keV. A 67Co level scheme has been deduced. Proposed spin and parities suggest a spherical (7/2-) 67Co ground state and a deformed first excited (1/2-) state at 492 keV, interpreted as a proton 1p-2h prolate intruder state.Comment: 4 pages, 5 figures, preprint submitted to Physical Review Letter