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Oxygen-driven de-alloying of Fe-14Cr-12Ni-10Mn-3Cu-2.5Al-1Nb austenitic steel at 500 °C in static Pb-Bi eutectic with concentration of dissolved oxygen alternating from ∼10<sup>-6</sup> to 10<sup>-9</sup> mass% for 10000 h
Get PDFA high-Mn austenitic steel Fe-14Cr-12Ni-10Mn-3Cu-2.5Al-1Nb was tested at 500 °C in static Pb-Bi eutectic for 10000 h. In the course of the test, oxygen concentration in liquid metal was cycled from ∼10-6 to ∼10-9 mass%, which provides oxidation and dissolution regimes, respectively. After 10000 h exposure steel showed formation of ferrite corrosion zone depleted in Mn, Ni, Cu, Cr, Fe and penetrated by Pb and Bi. Average depth of corrosion is 15±5 µm, while maximum corrosion depth locally reaches ∼35 µm. Dissolved Mn and Cr re-precipitated in the vicinity of steel surface in a form of stratified Mn-O/Cr-Mn-O oxide scale. Obtained results were compared to those of similar Al-alloyed austenitic steels with lower Mn content, which exhibited protective oxidation under same test conditions. The phenomenological mechanism of oxygen-driven de-alloying of steel in Pb-Bi[O] is discussed.</p
L’IA championne des jeux d’échecs et de Go (partie 2)
No full textCet article en deux parties explore l’évolution historique de l’intelligence artificielle et des concepts mathématiques sous-jacents, en se concentrant sur la théorie des jeux comme étalon dans le développement des IA. Lors de cette seconde partie, nous montrons comment l’introduction de l’aléatoire puis par la suite des réseaux de neurones artificiels a permis de créer une nouvelle génération de programmes capables de surpasser les humains aux échecs et au jeu de Go. Nous explorons un peu les mathématiques derrière la notion de réseau de neurones artificiels
Correction to:PTH1 receptor agonists for fracture risk: a systematic review and network meta-analysis (Osteoporosis International, (2025), 10.1007/s00198-025-07440-1)
No full textThe original online version of this article was revised: In this article, the author Olivier Bruyère's name was missing; the order in which the authors appeared in the author list was incorrectly given as: Charlotte Beaudart 1,2 · Nicola Veronese 1,3 · Jonathan Douxfils 4,5,6 · Jotheeswaran Amuthavalli Thiyagarajan 7 · Francesco Bolzetta 8 · Paolo Albanese 8 · Gianpaolo Voltan 8 · Majed Alokail 9 · Nicholas C. Harvey 1,10 · Nicholas R. Fuggle 1,10 · René Rizzoli 1,11 · Jean‑Yves Reginster 1,9 where it should have been: Charlotte Beaudart 1,2, Nicola Veronese 1,3, Jonathan Douxfils 4,5,6, Jotheeswaran Amuthavalli Thiyagarajan 7, Francesco Bolzetta 8, Paolo Albanese 8, Gianpaolo Voltan 8, Majed Alokail 9, Nicholas C. Harvey 1,10, Nicholas R. Fuggle 1,10, Olivier Bruyère 1,11, René Rizzoli 1,12, Jean-Yves Reginster 1,9 In this article, the affiliation “Research Unit in Public Health, Epidemiology and Health Economics, University of Liege, Liege, Belgium” for Olivier Bruyère was missing. The original article has been corrected.</p
Polymetallic interactions of Zn-Pb-Cu in blue/green-colored speleothems from Malaval Cave (France)
No full textSpeleothems rarely exhibit stunning colors such as red, yellow, green, or blue. The colorations are often linked to elevated heavy metal ion concentration in the drip water and thus to a metal source/pollution in the catchment area. Here the blue-green speleothems coloration in Malaval Cave (Lozère, France) is characterized by a wide panel of optical, mineralogical and geochemical techniques. These techniques were applied on several small blue or white stalactites and a larger greenish stalactite. The speleothems are mostly composed of aragonite and contain variable amounts of Zn, Cu and Pb, which cause the colorations. Zn and Cu are mostly present in substitution in the aragonite and Cu 2+ is the main cause of the blue coloration. Zn is also found in small amorphous gel particles, containing minor amounts of Mg, Cu and Si. These phases are responsible for microscopical scale variations in the blue coloration. Pb is present as Pb 2+ ions in substitution within the aragonite, creating a saturated blue-to-greenish coloration. This coloration may depend on the Pb/Zn ratio due to metallic interaction. Pb, Zn and Cu ratios indicate that Pb likely deposited from distinct fluids and at a different timing than Cu and Zn. All three metals likely originate from the leaching of Pb[sbnd]Zn ores in the Jurassic formations surrounding the cave.</p
Carbon-Based Bifunctional Lewis/Brønsted Acid Catalysts for 5-HMF Production from Cellobiose
No full textBifunctional carbon-based acid catalysts presenting Brønsted and Lewis acid sites in different proportions were synthesized by grafting mesoporous aluminosilicate patches in coexistence with benzyl sulfonic moieties on the solid's surface. The final bifunctional systems were obtained by development of a methodology allowing the production of a model discontinuous silica layer on the carbon substrate before applying the optimized procedure to the desired alumino-silicate layer. Patches were necessary to expose bare carbon surfaces for sulfonic acid grafting employing a diazonium coupling methodology to ensure robust anchoring. The bifunctional solids and their monofunctional counterparts were fully characterized and their acidic nature, together with the presence of both Brønsted and Lewis acid sites, was assessed by Py-FTIR spectroscopy, NH3-TPD, solid-state 31P MAS NMR, and Boehm back titration. The attainment of a mesoporous discontinuous oxide framework was confirmed by nitrogen physisorption and SEM/TEM observations. Finally, the catalytic performance of both the produced bifunctional systems and their monofunctional counterparts was investigated and compared for the upgrading of cellobiose to 5-hydroxymethylfurfural (5-HMF). A maximal yield of 37% of 5-HMF out of a 96% of cellobiose conversion was attained after 23 h with catalyst I4@BATEOS/SO3H in a designed solvent mixture (THF:mQ water) at 423 K.</p
Persisting thrombomodulin resistance at 3 months after liver transplantation in children with cirrhosis
No full textBACKGROUND: The coagulation cascade in pediatric cirrhotic patients appears rebalanced, similar to adults, with few true hemostasis-related bleeds or thromboembolic events before liver transplantation. Vascular thrombosis is an important post-liver transplantation complication. Few papers have addressed the recovery of the coagulation cascade after liver transplantation.OBJECTIVES: We aimed to assess the coagulation cascade, with both measurement of individual factors and a global hemostasis assay, before living donor liver transplantation and to investigate its recovery 3 months after transplantation, when liver function has normalized.METHODS: From January 2022 to July 2023, pediatric cirrhotic patients were prospectively enrolled 1 day before liver transplantation. An age-matched control group was included for comparison. Routine hemostasis tests, levels of coagulation factors and natural anticoagulants, and thrombomodulin-modified thrombin generation were determined on automated coagulation analyzers at inclusion and 3 months after liver transplantation.RESULTS: Twenty-seven pediatric patients with cirrhosis, primarily of cholestatic origin, and 10 controls were enrolled. Sixteen patients were sampled 3 months after liver transplantation. Pediatric end-stage liver disease scores ranged from -10 to 44. A rebalanced coagulation cascade was confirmed in cirrhotic children, indicated by a thrombomodulin-modified thrombin generation assay similar to controls, although with higher interpatient variability. Interestingly, 3 months posttransplant, coagulation was not completely normalized. In the majority of patients resistance to thrombomodulin persisted.CONCLUSION: This study confirmed a rebalanced coagulation system in pediatric cirrhotic patients before liver transplantation. Three months posttransplant thrombomodulin resistance persisted. Whereas this contributes to thrombotic complications observed after liver transplantation, remains to be elucidated.</p
Metal phthalocyanines and imidazolium bromide Copolymers supported on multi-walled carbon nanotubes:: a "lego-like" assembly of hybrid bifunctional materials applied for CO2 conversion
No full textThe present study explores the development of hybrid heterogeneous bifunctional catalysts supported on multi-walled carbon nanotubes (MWCNT) for CO2 valorization in the synthesis of cyclic carbonates. These materials integrate both nucleophilic species (imidazolium bromide) and Lewis acid species (magnesium, copper, and zinc phthalocyanines), revealing improved catalytic activity through synergistic effects. MWCNT are employed as support enhancing the accessibility of active sites and the overall catalytic performance. Three different metal-phthalocyanines with imidazole moieties (MgPC-Im4, CuPC-Im4 and ZnPC-Im4) were covalently anchored onto MWCNT through an atom economic polymerization process, resulting in new bifunctional materials (MPC@MWCNT) in which the polymeric network fully covers the nanotubes longitudinally. Comprehensive characterization of the hybrids by using different techniques confirmed the successful synthesis of these materials. Catalytic testing of the MPC@MWCNT materials in epoxide-CO2 cycloaddition reactions revealed that the MgPC@MWCNT hybrid exhibited superior catalytic activity compared to its unsupported counterpart, highlighting the benefits of the MWCNT as support (TON = 8050 vs TON = 7120), reaching very high TON values (up to 19920) at very low catalytic loadings (0.004–0.0013 mol% based on metal content). Importantly, this study introduces a simple yet effective novel method for covalently attaching high amounts of metal-phthalocyanines onto MWCNT. Potentially, the "lego-like" approach of this method allows for the creation of diverse materials with different metal centres, enabling access to a number of different applications in the field of Materials Science
The PLATO mission
No full textPLATO (PLAnetary Transits and Oscillations of stars) is ESA’s M3 mission designed to detect and characterise extrasolar planets and perform asteroseismic monitoring of a large number of stars. PLATO will detect small planets (down to <2REarth) around bright stars (<11 mag), including terrestrial planets in the habitable zone of solar-like stars. With the complement of radial velocity observations from the ground, planets will be characterised for their radius, mass, and age with high accuracy (5%, 10%, 10% for an Earth-Sun combination respectively). PLATO will provide us with a large-scale catalogue of well-characterised small planets up to intermediate orbital periods, relevant for a meaningful comparison to planet formation theories and to better understand planet evolution. It will make possible comparative exoplanetology to place our Solar System planets in a broader context. In parallel, PLATO will study (host) stars using asteroseismology, allowing us to determine the stellar properties with high accuracy, substantially enhancing our knowledge of stellar structure and evolution. The payload instrument consists of 26 cameras with 12cm aperture each. For at least four years, the mission will perform high-precision photometric measurements. Here we review the science objectives, present PLATO‘s target samples and fields, provide an overview of expected core science performance as well as a description of the instrument and the mission profile towards the end of the serial production of the flight cameras. PLATO is scheduled for a launch date end 2026. This overview therefore provides a summary of the mission to the community in preparation of the upcoming operational phases.</p
European mammal turnover driven by a global rapid warming event preceding the Paleocene–Eocene Thermal Maximum
No full textA brief global warming event known as the Pre-Onset Excursion (POE) occurred just before the Paleocene–Eocene Thermal Maximum (PETM, 56 Mya). The deconvolution of the evolutionary consequences of these two hyperthermal events is puzzling because of their close temporal proximity and the lack of comprehensive, well-calibrated paleontological records, especially in terrestrial environments. As a consequence, the impact of the POE on mammalian evolution and its role in shaping PETM faunas remains unclear. Here, we report from France a mammalian fauna, named Albas, which is interpreted to postdate the POE and predate the PETM. The absence of artiodactyls, perissodactyls, and euprimates at Albas lends support to the controversial hypothesis that these “modern” mammal groups appeared in the European fossil record during the PETM. In contrast, Albas yielded the European first definitive Paleocene record of metatherians, paromomyid primates, “creodonts,” and rodents, challenging the assumption that these groups migrated into Europe during the PETM. Because the majority of them originated from North American pre-POE species, we tentatively suggest that these “precursor” dispersers entered Europe during the POE. Similar to the modern orders during the PETM, these “precursor” dispersers likely entered Europe through corridors in the continuous evergreen forest belt at high latitudes. Our findings highlight how a brief warming event in the Arctic during the latest Paleocene, such as the POE (which could result in a release of carbon into the atmosphere similar to cumulative ongoing anthropogenic emissions), significantly influenced the evolutionary dynamics of European mammals.</p