Ref HAL: inserm-02904593_v1
PMID 32616916
DOI: 10.1038/s41598-020-67934-2
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Neurofilament light chain (NfL) has been demonstrated to correlate with multiple sclerosis disease severity as well as treatment response. Nevertheless, additional serum biomarkers are still needed to better differentiate disease activity from disease progression. The aim of our study was to assess serum glial fibrillary acid protein (s-GFAP) and neurofilament light chain (s-NfL) in a cohort of 129 multiple sclerosis (MS) patients. Eighteen primary progressive multiple sclerosis (PPMS) and 111 relapsing remitting MS (RRMS) were included. We showed that these 2 biomarkers were significantly correlated with each other (R = 0.72, p < 0.001). Moreover, both biomarkers were higher in PPMS than in RRMS even if multivariate analysis only confirmed this difference for s-GFAP (130.3 ± 72.8 pg/ml vs 83.4 ± 41.1 pg/ml, p = 0.008). Finally, s-GFAP was correlated with white matter lesion load and inversely correlated with WM and GM volume. Our results seem to confirm the added value of s-GFAP in the context of multiple sclerosis.

Ref HAL: hal-02904329_v1
DOI: 10.1073/pnas.2005638117
WoS: WOS:000546772500002
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Ref HAL: tel-02902601_v1
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La compréhension de la structure et du comportement mécanique des matériaux àl’échelle microscopique est cruciale pour la conception de nouveaux produits aux pro-priétés spécifiques. Cette thèse vise à obtenir des informations microscopiques sur lespropriétés, notamment celles de la fracture, des verres d’oxydes qui sont parmi lesmatériaux les plus utilisés au monde. À cette fin, nous utilisons des techniques desimulation atomistique de pointe pour étudier la silice et des silicates de sodium, c’est-à-dire les compositions représentatives pour de nombreux verres d’oxydes. À l’aide desimulations de dynamique moléculaire à grande échelle, la fracture dynamique des ver-res est étudiée de manière approfondie. Nous montrons que les propriétés mécaniquesdes verres sont considérablement plus sensibles au potentiel d’interaction et au pro-tocole de simulation utilisés qu’à leurs propriétés structurelles. La fracture du verrede silice est due aux ruptures de liaisons en pointe de fissure, tandis que la fracturedes verres riches en Na s’accompagne d’une croissance et d’une coalescence des cavités.Nous montrons également que l’origine microscopique du comportement transitoireprésenté par la rigidité des verres en fonction de leur composition se trouve dans ledéplacements atomiques non affines des atomes constituants. On constate que lessurfaces générées suite à la fracture sont considérablement plus rugueuses que les sur-faces formées par fusion et présentent un comportement en loi logarithmique à l’échellenanométrique (≤ 10 nm). En utilisant des simulations premiers principes, les signa-tures vibrationnelles et électroniques de certaines unités structurales, abondantes surla surface du verre, sont identifiées. De plus, l’ionicité et la force de divers types de li-aisons sont extraites à partir de ces simulations. Enfin, nous introduisons une méthodenouvelle pour caractériser la structure des liquides et des verres. Notre analyse montreque ces systèmes ont une structure tridimensionnelle étonnamment ordonnée.

Ref HAL: tel-02893703_v1
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Biology offers new systems for Physics, namely proteins and molecular motors in interaction with biopolymers like DNA and messenger RNA. This field is at the interface between active matter, polymer physics, and physics of colloids. Interestingly, cells also need to increase locally concentrations of proteins in a phase transition-like mechanism to realize vital function like cell division, DNA repair, DNA segregation etc. During this HDR defense, I will offer a physical perspective of intracellular phase transition with the example of bacterial DNA segregation. I will also discuss the motion of ribosomes along messenger RNA, an example of unidimensional inhomogeneous transport giving rise to different dynamical regimes.

Ref HAL: hal-02890142_v1
Ref Arxiv: 1908.04806
DOI: 10.1088/1751-8121/ab604e
Ref. & Cit.: NASA ADS
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A description of the embedding of a centrally extended Askey–Wilson algebra, AW(3), in Uq(sl2) 3 is given in terms of the universal R-matrix of Uq(sl2). The generators of the centralizer of Uq(sl2) in its three-fold tensor product are naturally expressed through conjugations of Casimir elements with R. They are seen as the images of the generators of AW(3) under the embedding map by showing that they obey the AW(3) relations. This is achieved by introducing a natural coaction also constructed with the help of the R-matrix.

Ref HAL: hal-02890130_v1
Ref Arxiv: 1909.06426
DOI: 10.1007/s11005-019-01249-w
Ref. & Cit.: NASA ADS
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The Bannai-Ito algebra BI(n) is viewed as the centralizer of the action of osp(1|2) in the n-fold tensor product of the universal algebra of this Lie superalgebra. The generators of this centralizer are constructed with the help of the universal R-matrix of osp(1|2). The specific structure of the osp(1|2) embeddings to which the centralizing elements are attached as Casimir elements is explained. With the generators defined, the structure relations of BI(n) are derived from those of BI(3) by repeated action of the coproduct and using properties of the R-matrix and of the generators of the symmetric group Sn.

Commentaires: 10 pages, 15 ref.

Ref HAL: hal-02880608_v1
Ref Arxiv: 1912.06021
DOI: 10.1103/PhysRevResearch.2.023203
Ref. & Cit.: NASA ADS
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We numerically study yielding in two-dimensional glasses which are generated with a very wide range of stabilities by swap Monte-Carlo simulations and then slowly deformed at zero temperature. We provide strong numerical evidence that stable glasses yield via a nonequilibrium discontinuous transition in the thermodynamic limit. A critical point separates this brittle yielding from the ductile one observed in less stable glasses. We find that two-dimensional glasses yield similarly to their three-dimensional counterparts but display larger sample-to-sample disorder-induced fluctuations, stronger finite-size effects, and rougher spatial wandering of the observed shear bands. These findings strongly constrain effective theories of yielding.