Modulated spin dynamics of [Co2] coordination helicates via differential strand composition.

Coordination supramolecular chemistry provides a versatile entry into materials with functionalities of technological relevance at the nanoscale. Here, we describe how two different bis-pyrazolylpyridine ligands (L1 and L2) assemble with Co(II) ions into dinuclear triple-stranded helicates, in turn, encapsulating different anionic guests. These constructs are described as (Cl@[Co2(L1)3])3+, (SiF6@[Co2(L1)(L2)3])2+ and (ClO4@[Co2(L2)3])3+, as established by single-crystal X-ray diffraction. Extensive magnetic and calorimetric measurements, numerical treatments and theoretical calculations reveal that the individual Co(II) centers of these supramolecular entities exhibit field-induced slow relaxation of magnetization, dominated by direct and Raman mechanisms. While the small variations in the spin dynamics are not easily correlated with the evident structural differences among the three species, the specific heat measurements suggest two vibronic pathways of magnetic relaxation: one that would be associated with the host lattice and another linked with the guest.

Dilute Gd hydroxycarbonate particles for localized spin qubit integration.

Molecular spins are considered as the quantum hardware to build hybrid quantum processors in which coupling to superconducting devices would provide the means to implement the necessary coherent manipulations. As an alternative to large magnetically-dilute crystals or concentrated nano-scale deposits of paramagnetic molecules that have been studied so far, the use of pre-formed sub-micronic spherical particles of a doped Gd@Y hydroxycarbonate is evaluated here. Particles with an adjustable number of spin carriers are prepared through the control of both particle size and doping. Bulk magnetic properties and continuous wave and time-domain-EPR spectroscopy show that the Gd spins in these particles are potential qubits with robust quantum coherence. Monolayers of densely-packed particles are then formed interfacially and transferred successfully to the surface of Nb superconducting resonators. Alternatively, these particles are disposed at controlled localizations as isolated groups of a few particles through Dip-Pen Nanolithography using colloidal organic dispersions as ink. Altogether, this study offers new material and methodologies relevant to the development of viable hybrid quantum processors.

Evaluation of triphenylene-based MOF ultrathin films for lithium batteries.

Metal-organic frameworks (MOFs) are attractive candidates to meet the requirement of next-generation batteries, as functional materials with a high surface area, well-defined metal centers, and organic linkers through coordination bonds. Due to their great tunability, MOFs have been investigated as electrodes or electrolytes in lithium batteries and more recently as protective layers in anode-less batteries. Here, we synthesize a Ni3(HHTP)2 MOF directly at the air-liquid interface of a Langmuir trough and grow the electrode on a conductive substrate by the transference process. The characterization during Langmuir film formation shows that the addition of crystallization time during the compression process enhances the formation of 2D crystalline domains, as observed by in situ grazing-incidence X-ray diffraction. Next, the transferred Ni3(HHTP)2 ultrathin films were studied as working electrodes in Li batteries in a half-cell configuration and compared with bare copper. The results show that the Ni3(HHTP)2 film protects the Cu collector from oxidation, and the negative charge accumulates in the organic ligand during the lithiation process while NiII oxidizes to NiIII, unlike other triphenylene-based MOFs with CuII or CoII metal nodes. The galvanostatic plating-stripping cycles of the batteries show that the inclusion of the crystallization time improves the coulombic efficiency, especially significantly in the first cycles when the SEI is formed. This work shows the Langmuir technique as a useful tool to test MOF based materials for batteries with the advantages of using a low amount of raw materials and without the need to introduce additives (binder and electron conductor) in the electrodes. The electrochemical study of this type of electrode allows a first screening to synthesize electrodes based on MOFs and can be a tool for the preparation of protective coatings under optimized conditions.

Successful use of rituximab for refractory hemophagocytic lymphohistiocytosis in a melanoma patient treated with targeted therapy.

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disease characterized by aberrant immune hyperactivation of T CD8 lymphocytes and macrophages driven by cytokine dysfunction. We report a 64-year-old man, with advanced BRAF-mutant melanoma treated by combined targeted therapies who had a recalcitrant and cortico-dependent Epstein-Barr virus (EBV)-induced HLH. One rituximab cycle led to a rapid and prolonged HLH remission which allowed to switch the targeted therapy for immunotherapy rituximab thus makes it possible to limit the use of corticosteroids, which limits the effectiveness of immunotherapy. The patient finally died of a cerebral tumoral progression 2 years later. Despite secondary hypogammaglobulinemia, we did not observe any severe infections during this period. This case suggests that rituximab can be a valuable option for EBV-induced HLH to avoid the T-suppressive effects of high-dose of corticosteroids in immunotherapy-treated patients.

Influence of the Surface Chemistry of Metal-Organic Polyhedra in Their Assembly into Ultrathin Films for Gas Separation.

The formation of ultrathin films of Rh-based porous metal-organic polyhedra (Rh-MOPs) by the Langmuir-Blodgett method has been explored. Homogeneous and dense monolayer films were formed at the air-water interface either using two different coordinatively alkyl-functionalized Rh-MOPs (HRhMOP(diz)12 and HRhMOP(oiz)12) or by in situ incorporation of aliphatic chains to the axial sites of dirhodium paddlewheels of another Rh-MOP (OHRhMOP) at the air-liquid interface. All these Rh-MOP monolayers were successively deposited onto different substrates in order to obtain multilayer films with controllable thicknesses. Aliphatic chains were partially removed from HRhMOP(diz)12 films post-synthetically by a simple acid treatment, resulting in a relevant modification of the film hydrophobicity. Moreover, the CO2/N2 separation performance of Rh-MOP-supported membranes was also evaluated, proving that they can be used as selective layers for efficient CO2 separation.

Tacrolimus 0.1% versus ciclopiroxolamine 1% for maintenance therapy in patients with severe facial seborrheic dermatitis: A multicenter, double-blind, randomized controlled study.

BACKGROUND: No long-term maintenance therapy has been tested in patients with seborrheic dermatitis (SD). OBJECTIVE: We sought to compare the efficacy and tolerance of tacrolimus 0.1% ointment versus ciclopiroxolamine 1% cream as maintenance therapy for severe SD. METHODS: This double-blind randomized controlled study was conducted from 2014 to 2017 in 5 Dermatology Departments and 15 dermatology practices in France. Consecutive patients with severe and chronic facial SD were included. Patients were initially treated with desonide 0.05% cream twice daily for 7 days. Patients cleared after this open phase were randomized to receive tacrolimus 0.1% or ciclopiroxolamine 1% cream 2 times a week 24 weeks. The primary endpoint was disease-free-duration, defined as the time from randomization to first relapse. RESULTS: One hundred fourteen patients were randomized (tacrolimus, n = 57; ciclopiroxolamine, n = 57). Twelve patients relapsed in the tacrolimus group after a median delay of 91.5 days (range 15-195 days) versus 23 patients in the ciclopiroxolamine group (median delay, 27 days [range 13-201 days]). Comparison of disease-free duration curves showed that patients in the tacrolimus group had a longer duration of complete remission than those in the ciclopiroxolamine group (P = .018), corresponding to a hazard ratio of relapse of 0.44 (95% confidence interval 0.22-0.89; P = .022). LIMITATIONS: The theoretical sample size was not reached. CONCLUSION: Tacrolimus 0.1% is more effective than ciclopiroxolamine 1% as maintenance therapy for patients with facial SD.