Search

The universe is mainly filled with dark matter, which nature remains unknown. A particularly interesting hypothesis is that it is made of new light particles called axions. Their detection requires intense magnetic fields. In this paper, we present the results of measurements at 4.2 K (LHe bath) in self-field of two High-Temperature Superconductors (HTS) REBCO single pancakes of about 800 turns from two different manufacturers. Those prototypes have been fabricated and tested to evaluate the latest present-day performances of HTS tapes suitable for the project. An axial magnetic induction of about 19 T has been reached with an operating current of 1400 A. The magnet survived to a quench at full energy (around 2050 A/mm2 in the winding pack and 26 T peak field on the tape), which confirmed that the NI single pancake coil are effectively self-protected at such strong working conditions. However, we also confirmed that there are complexities, particularly in the mechanical and cryogenic areas, that have to be considered in the machine design.

The Metal as Insulation and more generally the No-Insulation windings are promising for the protection of DC and slow ramping HTS magnets. The modeling of the thermal behavior during a quench in order to design the protection of a magnet is highly dependent on parameters set by materials and fabrication. The electrical resistance between turns has been widely studied worldwide, but the turn-to-turn thermal conductivity of MI windings stays relatively unknown. Turn-to-turn thermal conductivity may have a significant role in the dynamics of a quench and on the hot spot temperature. This motivated us to develop a specific apparatus for evaluating this turn-to-turn thermal conductivity. Because we are working with HTS dry stacks the thermal conductivity depends not only on temperature but also on radial pressure. This paper present the design of an apparatus to evaluate the thermal conductivity of an HTS stack under different radial compression and at different temperature. The measurements are made with an isoperibolic cell using the steady-state differential method. This article details the mechanical and thermal design and the fabrication steps of the first thermal samples. We also present the first results of thermal conductivity obtained at 20 MPa and 5.5 K, which is close to our theoretical prediction.

The aim of the SuperEMFL project is to design a 32 T and a 40 T or more all superconducting magnets, and to improve the development of very high magnetic fields. To generate such high magnetic inductions, a high temperature superconducting (HTS) magnet is inserted into a low temperature superconducting (LTS) magnet. The latter can be either a 150 mm user bore diameter magnet generating 19 T or a 250 mm user bore diameter generating 15 T, and will operate in liquid helium at 4.2 K. To reach high magnetic fields of 32 T and 40 T respectively, the HTS insert is made of metal-as-insulation (MI) windings of REBCO tape and can be designed as a single solenoid or as nested coils. This article focuses on the design of the HTS insert for the 40 T+ magnet, based on a multi-physics parametric study under constraints of geometry, current margin on the load line taking into account different anisotropic fits of the critical current of REBCO conductor, mechanical stress and deformation with analytical formulations of MI windings. Different designs are studied including high volume and high field magnets.

A refurbished metal-as-insulation (MI) HTS insert comprised of DP coils with replaced inner joints was charged under various magnetic field (Bext) from 0 to 18 T at 4.2 K for testing. However, the refurbished insert could not be charged up to its maximum field, because the cryogenic condition tended to be unstable with a high helium boiling rate above 28 T. Therefore, to investigate the cooling issue, four Cernox sensors were installed in refurbished insert. The temperature of each position while powering the insert was measured under various Bext. In addition, we qualified a new simplified protection scheme without the usual detection and dump circuit during a quench at Bext = 9 T of the insert. Detailed experimental results about charging and quenching tests of the insert are presented and discussed in this paper.

The physical and electrical properties of four recent REBCO CC were assessed: 1) THEVA; 2) Shanghai Supercond. Technology; 3) Faraday Factory Japan; and 4) Fujikura. For estimating their physical properties, the delamination strength of each tape was checked by removing a polyimide ribbon sticked on the tape and by cutting the tape after pre-tinning. Their windability and the uniformity of their thickness were also investigated through our metal-as-insulation winding process. For evaluating their electrical properties, their critical current was measured at 4.2 K under various external magnetic fields perpendicular to their ab-plane. Joint samples of each tape were fabricated and tested in a bath of liquid nitrogen at 77 K in self-field. The results are described in this paper for the four tapes.

CEA Saclay is working since 2008 on High Temperature Superconductor (HTS) developments for accelerator magnet application. Two dipole models were realized at CEA Saclay: the EuCARD block dipole magnet and the EuCARD2 cosine-theta dipole magnet. The EuCARD block dipole magnet, relying on 12-mm REBCO tapes, was the first step to demonstrate the potential of REBCO type HTS ceramic tapes to generate 5-T field. The magnet manufacturing was completed in 2016, and the magnet cold tests performed at CEA in 2017. Magnet design and manufacturing process, as well as first cold tests of the magnet have already been presented in 2018. Since then, additional cold tests have been carried out up to the nominal current and beyond, reaching a record induction field of 5.37 T without quench. The EuCARD2 cosine-theta dipole magnet, relying on REBCO HTS Roebel cable, aimed also to produce a central 5-T dipole field, but with an accelerator-type dipole design and accelerator magnet field quality. The detailed design and coil manufacturing process have already been presented in 2019. Between 2019 and 2020, three coils were built, with a SuperOx tape based Roebel cable. In 2021, the magnet has been assembled, at CEA Saclay, with the last two produced coils, and in 2022 it has been cold tested at CERN in self field configuration. Despite the degraded performance of one of the coils, directly linked to an overheating problem during its production, the cold tests made it possible to highlight the good potential of the cos-theta design with Roebel cable.

In the framework of the SuperEMFL (Super European Magnetic Field Labs) project, we have previously studied numerous possible pre-designs made of an HTS insert with a LTS outsert to achieve a central magnetic induction of 32 T and 40 T. From the most interesting designs, the behavior of the magnet has been studied during the quench of one of the superconducting parts, either LTS or HTS one. This study includes a multi-physics analysis (magnetics, thermics, mechanics) of both parts and has been led with two different codes, each one based on a very different protection principle. We showed that the quench of the LTS outsert, as it is adequately protected, caused a quasi-symmetrical quench of the HTS part, with a limited increase of the temperature. However, the ignition of the quench within the HTS insert leads to an asymmetrical current distribution and to a significant axial force resultant generated on the LTS part. This may necessitate mechanical reinforcement to address the resulting imbalance.

Les infirmiers diplômés d’état (IDE) de réanimation sont des acteurs essentiels dans la prise en charge de l’équilibre glycémique en réanimation, aussi bien dans le dépistage des complications que dans l’instauration et la surveillance des thérapeutiques. Il est important de connaître les mécanismes physiopathologiques conduisant à l’hypo- comme l’hyperglycémie en réanimation et de comprendre qu’un geste aussi banal qu’une glycémie capillaire peut avoir un impact sur le devenir du patient, même non diabétique.

Le comité Infirmier Diplômé d’État (IDE) de Réanimation de la Société française d’anesthésie et de réanimation (SFAR) a pour mission de promouvoir le rôle essentiel des paramédicaux au sein des unités de réanimation et d’accompagner les IDE de réanimation dans leur développement professionnel. Le comité des IDE de réanimation, qui est composé de 13 membres et de plusieurs invités, compte de nombreuses missions et travaille en collaboration avec plusieurs autres comités de la SFAR. La création et la pérennisation de programmes de formation en ligne comme les webinars, la diffusion des référentiels en lien avec les pratiques professionnelles et l’organisation des soins ainsi que la promotion de la recherche paramédicale servent l’objectif majeur du comité : la valorisation de la profession d’infirmier en réanimation. Aujourd’hui, le comité IDE veut étendre son rayonnement afin d’améliorer la diffusion des contenus spécifiques à sa profession et ainsi continuer d’accompagner au mieux les professionnels.

Le comité IDE de réanimation, de par ses missions au sein de la SFAR, s’est intéressé aux relations des paramédicaux avec les sociétés savantes. À peine 60 % des paramédicaux sait ce qu’est une société savante. Ils y recherchent principalement des recommandations, de l’actualité et de la formation. Si les tarifs sont un frein à l’adhésion, la moitié des professionnels interrogés se disent prêts à investir pour leur formation, à condition d’un élargissement des accès et des contenus.

Maturation of B cells in Germinal Centers (GC) is a hallmark in adaptive immunity and the basis of successful vaccines that protect us against lethal infections. Nonetheless, vaccination efficacy is very much reduced in aged population and against highly mutagenic viruses. Therefore, it is key to understand how B cell selection takes place in GC in order to develop new and fully protective vaccines. The cellular mechanisms that control selection of GC B cells are performed by different T cell populations. On one side, cognate entanglement of B cells with T follicular helper (Tfh) cells through cytokines and co-stimulatory signals promotes survival, proliferation, mutagenesis and terminal differentiation of GC B cells. On the other hand, regulatory T cells have also been reported within GC and interfere with T cell help for antibody production. These cells have been classified as a distinct T cell sub-population called T Follicular regulatory cells (Tfr). In this review, we investigate the phenotype, function and differentiation of these two cell populations. In addition, based on the different functions of these cell subsets, we highlight the open questions surrounding their heterogeneity.

Sept ans après la loi Claeys-Léonetti, le Comité infirmier de réanimation de la Société française d’anesthésie-réanimation a adressé aux infirmiers et aides-soignants de réanimation un questionnaire en ligne pour évaluer leurs connaissances et leurs perceptions concernant les dispositifs législatifs actuels encadrant la fin de vie, et pour analyser leurs représentations concernant leur propre fin de vie.

La thérapie nutritionnelle est un enjeu majeur de la prise en charge des patients de réanimation du fait de son impact sur la morbi-mortalité. Les infirmier.es diplômé.es d’état de réanimation ont un rôle essentiel dans la mise en œuvre de la nutrition entérale, comprenant la gestion de l’interface d’administration, la connaissance des différents solutés et le dépistage des complications. Connaître les bases physiopathologiques de la dysfonction métabolique permet de mieux appréhender le choix des solutés et des débits à un moment donné du séjour. Participer à la rédaction du protocole de nutrition de son service, en collaboration avec l’équipe médicale et l’équipe de diététique, améliore la qualité des soins viaune adhésion renforcée aux recommandations.

IatroMed 360̊ #néonatologie est une chambre des erreurs en parcours immersif numérique à 360̊ focalisée sur la prise en charge médicamenteuse en réanimation néonatale. L’objectif de ce travail était d’évaluer la satisfaction et l’impact de la formation avec cet outil sur l’évolution des connaissances et compétences des professionnels de santé de néonatalogie d’un CHU français.

La recherche paramédicale se développe d’année en année en France. La société française d’anesthésie réanimation (SFAR) et le comité IDE de réanimation ont souhaité créer une bourse à destination des IDE (infirmier.e.s diplomé.e.s d’état) de soins critiques en 2022, afin d’encourager le développement de la recherche infirmière dans le domaine des soins critiques. Le montant de cette bourse est de 5000 euros et le lauréat du prix s’engage à présenter l’état d’avancement de son projet lors des sessions IDE du Congrès de la SFAR suivant. Les candidatures 2023 pour cette bourse sont ouvertes depuis le 01/01/2023 et seront clôturées le 23 avril à minuit.

CXCR4 plays a central role in B cell immune response, notably by promoting plasma cell (PC) migration and maintenance in the bone marrow (BM). Gain-of-function mutations in CXCR4affecting receptor desensitization have been reported in the rare immunodeficiency called WHIM syndrome (WS). Despite lymphopenia, patients mount an immune response but fail to maintain it over time. Using a knockin mouse model phenocopying WS, we showed that, counter-intuitively, a gain of Cxcr4 function inhibited the maintenance of antibody titers after immunization. Although the Cxcr4mutation intrinsically and locally promoted germinal center response and PC differentiation, antigen-specific PCs were barely detected in the BM, a defect mirrored by early accumulation of immature plasmablasts potentially occupying the survival niches for long-lived PCs. Therefore, fine-tuning of Cxcr4 desensitization is critically required for efficient PC differentiation and maintenance, and absence of such a regulatory process may account for the defective humoral immunity observed in WS patients.

Le pemphigus est caractérisé par des auto-Ac pathogènes ciblant les cadhérines inter-kératinocytaires desmogléines (Dsg) 1 et 3, et par une prédisposition HLADRB1-0402. Le rituximab associé à une corticothérapie courte est le traitement des formes modérées à sévères (essai Ritux3). Nous rapportons l’effet du rituximab sur la composante circulante des LT spécifiques de l’antigène (Ag) qui régulent spécifiquement la réponse B : les LT folliculaires auxiliaires (Tfh) et régulateurs (Tfr).

Meniscal lesions are frequent during sport practice. Although the lateral meniscus is affected in only 25% of all meniscal lesions, lateral lesions are usually known to have poor clinical outcome. Our monocentric study consisted in the systematic evaluation of all patients treated in our unit for a unique lesion of the lateral meniscus in an otherwise normal knee. Follow-up was of at least ten years. Functional results were rated with four grades currently used in traumatology practice. Statistical analysis was conducted to identify predictive factors of poor outcome. Thirty-nine patients were included. Functional assessment showed 12% of excellent, 41% of good, 35% of mediocre and 12% of poor results on Arpege's score; 65% of good and excellent and 35% of mediocre results on Lysholm's score. The average subjective IKDC score 58±15, the objective score showed 0% of A, 88% of B and 12% of C. The average Koos score was 83.7±17. Better outcome was noted in patients with horizontal injuries (P=0.04) or in patients with central segment injury (P=0.05). Similar data concerning the poor functional outcome of lateral meniscus tears have been published. Only two thirds of patients claim good or excellent results after 10 years.

La chirurgie naviguée permet en théorie d’optimiser les résultats des prothèses totales de hanche (PTH). Les systèmes de navigation se sont sophistiqués sans devenir incontournables, en partie à cause de suspicion vis-à-vis de leur fiabilité. Aussi nous avons mené une étude pour : (1) établir et comparer la précision des données d’allongement de trois navigateurs ; (2) analyser la corrélation entre les données d’allongement et de latéralisation issues des navigateurs et d’EOS™ ; (3) évaluer la réalisation des objectifs d’allongement à ±2 et 5mm ; (4) étudier l’occurrence d’échecs spécifiques.