ABSTRACT Lanthanum fluorogermanate glass samples were prepared by melt‐quenching in ternary compositions 55GeO 2 –15M 2 O–30LaF 3 , M being K or Na and doped with 0.25 mol% of Eu 2 O 3 . Thermal analysis by differential scanning calorimetry (DSC) technique allowed us to determine both glass transition and crystallization temperatures in bulk and powder samples. Heat treatments (HTs) were performed on the basis of DSC curves with increasing HT time and temperature, and glass–ceramics were obtained in both systems. In the potassium‐based glass composition, cubic KLaF 4 is precipitated for lower HT temperatures. However, for the sodium‐based glass, hexagonal NaLaF 4 is first precipitated at lower temperatures, whereas hexagonal fluorecite LaF 3 is also crystallized at higher temperatures. Eu 3+ spectroscopy identified strong emission dependency with the crystallization state and nature of crystalline phases. Emission bands related to electronic transitions from the 5 D 2 and 5 D 1 , usually not observed in oxide and even oxyfluoride glasses, were clearly identified and with relative strong intensity together with the well‐known Eu 3+ red emissions, pointing out unusual effective Eu 3+ blue and green emission in these glass–ceramics. Experimental lifetimes were useful to identify different Eu 3+ sites related with oxide/fluoride as well as glassy/crystalline environments.
Introduction:Non-small cell lung cancer (NSCLC) remains the leading cause of cancer-related mortality, particularly due to resistance induced by tumor-associated macrophages (TAMs)-exhibiting a M2-like phenotype-within the tumor microenvironment. The specific targeting of pro-tumoral M2 TAMs constitutes thus a major challenge in anticancer therapies but current strategies lack specificity. We produced and patented a monoclonal antibody, called mAb6-25, that specifically targets M2-like macrophages (M2M) but not M1-like macrophages (M1M) or monocytes. Here, we investigated the conjugation of this antibody on magnetic nanoparticles (MNPs) as a potential nanoplatform for specific M2 TAM targeting. Methods:Magnetic iron oxide multicore nanoflowers (NF) were functionalized with a fluorophore allowing their detection and the mAb6-25 for M2 TAM targeting. The M2M targeting by MNP-mAb6-25 was determined, comparatively to M1M, in 2D and 3D in vitro co-culture models with cancer cells by flow cytometry and confocal microscopy analysis, while MNP-mAb6-25 uptake was evaluated by NMR relaxometry. The in vivo M2 TAM targeting was analyzed in a xenograft mouse model of NSCLC by IVIS optical imaging. Results:We demonstrated that the MNP-mAb6-25 nanoplatform preferentially binds M2M compared to M1M (13-fold higher uptake in M2M) or cancer cells in monoculture as well as in 2D and 3D co-culture models mixing M2M or M1M with A549 NSCLC cells. Moreover, MNP-mAb6-25 internalized and accumulated in the lysosomes of M2M. The efficacy of intravenously injected MNP-mAb6-25 to target NSCLC sub-cutaneous xenografted models containing M2M was subsequently demonstrated. Conclusion:This study highlights the potential of MNP-mAb6-25 as a nanoplatform for selective targeting TAM-containing NSCLC tumors. This nanotechnology tool may lead to the development of new applications: one involving the imaging-based detection of pro-tumoral M2 TAMs by MRI, and the other involving their potential depletion through the application of localized magnetic fields, paving the way for imaging-guided diagnosis and further therapeutic evaluation.
Incorporating multiple anions into perovskite-type frameworks provides a handle to design innovative lattices and trigger exotic properties. Inverse Lieb lattices have been receiving substantial interest as hosts for d-wave altermagnetism. One mixed-anion system in which these lattices have been experimentally realized is layered oxychalcogenides. By employing a high-pressure, high-temperature synthesis method, we introduce Na2Mn2OS2 as an additional member of this family of compounds. Na2Mn2OS2 adopts an antiperovskite-derived structure, consisting of layers of face-sharing MnO2S4 octahedra. Magnetization and neutron diffraction data reveal that the phase undergoes magnetic ordering below 144 K. The low-temperature magnetic structure has zero net magnetization and is invariant under a combination of rotation and time reversal, thereby fulfilling the symmetry criteria to be considered as an altermagnet candidate. Electronic band structure calculations demonstrate that the phase contains spin-polarized bands, providing further evidence that Na2Mn2OS2 can be described as an altermagnet. An electrochemical investigation of this compound was performed, aiming both to tailor the physicochemical properties of the material through desodiation and to yield a possible Na-ion cathode material. While there are indications of Na-deintercalation, the charge compensation mechanism appears to involve irreversible sulfur oxidation rather than manganese oxidation, thus preventing the application of Na2Mn2OS2 as a positive electrode for Na-ion batteries.
Solid Oxide Fuel Cells (SOFCs) and Solid Oxide Electrolysis Cells (SOECs) are recognised for their potential energy efficiency inducing a reduction of greenhouse gas emissions 1 . However, the development of new, reliable and robust oxygen electrode materials remains a crucial challenge in improving overall performance. Based on the latest developments in research about electrodes materials and microstructures, 2,3 the present study is dedicated to new architectured oxygen electrodes as well as method for diagnosing electrodes. The study of the response of electrochemical systems in a three-electrode configuration has already been published in the literature using a single reference electrode (RE) 4 . It therefore becomes possible to separately determine the potential drop of the working electrode (WE), from that of the counter electrode (CE) 5 . Moreover, placing a RE on the oxygen side and hydrogen side enables a more comprehensive analysis of the electrochemical contribution of each electrode during operation. This technique will be helpful to diagnose the electrodes behaviour during operation but also to check the stability of materials or observe degradation during ageing tests. For this purpose, an electrolyte composed of gadolinium doped ceria (GDC) has been elaborated and its ion conductivity has been verified. Then, a porous GDC backbone has been deposited by screen printing on the electrolyte using optimised ink. This backbone was then infiltrated with a solution of praseodymium nitrate to obtain the architectured electrode GDC-Pr 6 O 11 . Finally, the Area Specific Resistance (ASR) has been measured on symmetrical half cells under air in the temperature range 800 °C to 500 °C. This work is first implemented in a three-electrode configuration. A symmetrical half-cell, composed of Pr₆O₁₁-GDC10/GDC10/GDC10-Pr₆O₁₁, is prepared according to the previously described protocol. The reference electrode is deposited around one of the two electrodes of the half-cell using a platinum lacquer. Electrochemical impedance spectroscopy measurements coupled to the application of a voltage varying from 0 to 1 V are then carried out over a temperature range from 800 °C to 600 °C, in order to characterise the polarizability of the structured electrode. Secondly, a four-electrode configuration was set up on a commercial cell which was made of NiO-8YSZ/8YSZ/GDC10/GDC-Pr 6 O 11 with the optimised oxygen electrode screen printed on it. Afterward, reference electrodes were placed on each side of the cell. This approach makes it possible not only to assess the performance of the electrode developed at the ICMCB, but also to dissociate the electrochemical contributions of each electrode. (1) Stambouli, A. B.; Traversa, E. Solid Oxide Fuel Cells (SOFCs): A Review of an Environmentally Clean and Efficient Source of Energy. Renewable & substainable energy reviews 2002 . (2) Tucker, M. C.; Cheng, L.; DeJonghe, L. C. Selection of Cathode Contact Materials for Solid Oxide Fuel Cells. Journal of Power Sources 2011 , 196 (20), 8313–8322. https://doi.org/10.1016/j.jpowsour.2011.06.044. (3) Nicollet, C.; Flura, A.; Vibhu, V.; Fourcade, S.; Rougier, A.; Bassat, J.-M.; Grenier, J.-C. Preparation and Characterization of Pr2NiO4+δ Infiltrated into Gd-Doped Ceria as SOFC Cathode. J Solid State Electrochem 2016 , 20 (7), 2071–2078. https://doi.org/10.1007/s10008-016-3211-x. (4) Cimenti, M.; Co, A. C.; Birss, V. I.; Hill, J. M. Distortions in Electrochemical Impedance Spectroscopy Measurements Using 3‐Electrode Methods in SOFC. I – Effect of Cell Geometry. Fuel Cells 2007 , 7 (5), 364–376. https://doi.org/10.1002/fuce.200700019. (5) Finklea, H.; Chen, X.; Gerdes, K.; Pakalapati, S.; Celik, I. Analysis of SOFCs Using Reference Electrodes. J. Electrochem. Soc. 2013 , 160 (9), F1055–F1066. https://doi.org/10.1149/2.093309jes. Figure 1
In this presentation 23 Na MAS NMR was used to probe the local structure, electronic structure and dynamics in several layered Na x MO 2 oxides for application in Na-ion batteries. Among them, P2-Na x CoO 2 appears to be a model material with a very specific phase diagram and unusual physical properties. 23 Na MAS NMR was used to characterize the changes in the electronic structure during Na deintercalation. 23 Na MAS was also used to characterize the local structure and dynamics versus temperature in several P2 or P3 Na x CoO 2 materials and P2-Na 1/2 VO 2 . In the latter, an increase of two orders of magnitude in its electronic conductivity has been observed at approximately 322 K and a structural transition has been found to occur simultaneously. At room temperature, high resolution powder diffraction and pair distribution function analysis reveal the triangular lattice formed by vanadium ions to be distorted by the formation of pseudo-trimers vanadium clusters. At 350 K, the mobility of the electronic charge carried by vanadium ions increases as evidenced by the increase in the electronic conductivity. The arrangement of sodium ordering in P2-Na 1/2 VO 2 , which maximizes sodium-sodium distances to lower electrostatic repulsions between alkali ions, is found to be unchanged across this transition, but the ionic mobility as observed by NMR, clearly change. Finally, the P2- Na 2+x Ni 2-x/2 TeO 6 (0 ≤ x ≤ 0.5) system provides a framework for investigating the effect of dual Na + substitution into the sodium layer and the transition-metal layer of the structure, and its effects on the electrochemical properties of the materials. The sodium substitution disrupts ordering within the transition-metal layer thereby disrupting Na + ordering in the adjacent sodium layers. Beyond a critical sodium concentration, the layer stacking shifts, and all voltage plateaus of the P2-Na 2 Ni 2 TeO 6 material are no longer observed. These results highlight how sodium ordering between the MO 2 layers and the electronic transport within the MO 2 layers are intimately correlated in Na x MO 2 type sodium layered oxides.
