A quantum homogeneous space of nilpotent matrices

A quantum deformation of the adjoint action of the special linear group on the variety of nilpotent matrices is introduced. New non-embedded quantum homogeneous spaces are obtained related to certain maximal coadjoint orbits, and known quantum homogeneous spaces are revisited.Comment: 12 page

A 2-categorical extension of Etingof–Kazhdan quantisation

Let k be a field of characteristic zero. Etingof and Kazhdan constructed a quantisation U_h(b) of any Lie bialgebra b over k, which depends on the choice of an associator Phi. They prove moreover that this quantisation is functorial in b. Remarkably, the quantum group U_h(b) is endowed with a Tannakian equivalence F_b from the braided tensor category of Drinfeld-Yetter modules over b, with deformed associativity constraints given by Phi, to that of Drinfeld-Yetter modules over U_h(b). In this paper, we prove that the equivalence F_b is functorial in b.Comment: Small revisions in Sections 2 and 6. An appendix added on the equivalence between admissible Drinfeld-Yetter modules over a QUE and modules over its quantum double. To appear in Selecta Math. 71 page

A short history of the 5-HT2C receptor: from the choroid plexus to depression, obesity and addiction treatment

This paper is a personal account on the discovery and characterization of the 5-HT2C receptor (first known as the 5- HT1C receptor) over 30 years ago and how it translated into a number of unsuspected features for a G protein-coupled receptor (GPCR) and a diversity of clinical applications. The 5-HT2C receptor is one of the most intriguing members of the GPCR superfamily. Initially referred to as 5-HT1CR, the 5-HT2CR was discovered while studying the pharmacological features and the distribution of [3H]mesulergine-labelled sites, primarily in the brain using radioligand binding and slice autoradiography. Mesulergine (SDZ CU-085), was, at the time, best defined as a ligand with serotonergic and dopaminergic properties. Autoradiographic studies showed remarkably strong [3H]mesulergine-labelling to the rat choroid plexus. [3H]mesulergine-labelled sites had pharmacological properties different from, at the time, known or purported 5-HT receptors. In spite of similarities with 5-HT2 binding, the new binding site was called 5-HT1C because of its very high affinity for 5-HT itself. Within the following 10 years, the 5-HT1CR (later named 5- HT2C) was extensively characterised pharmacologically, anatomically and functionally: it was one of the first 5-HT receptors to be sequenced and cloned. The 5-HT2CR is a GPCR, with a very complex gene structure. It constitutes a rarity in theGPCR family: many 5-HT2CR variants exist, especially in humans, due to RNA editing, in addition to a few 5-HT2CR splice variants. Intense research led to therapeutically active 5-HT2C receptor ligands, both antagonists (or inverse agonists) and agonists: keeping in mind that a number of antidepressants and antipsychotics are 5- HT2CR antagonists/inverse agonists. Agomelatine, a 5-HT2CR antagonist is registered for the treatment of major depression. The agonist Lorcaserin is registered for the treatment of aspects of obesity and has further potential in addiction, especially nicotine/ smoking. There is good evidence that the 5-HT2CR is involved in spinal cord injury-induced spasms of the lower limbs, which can be treated with 5-HT2CR antagonists/inverse agonists such as cyproheptadine or SB206553. The 5-HT2CR may play a role in schizophrenia and epilepsy. Vabicaserin, a 5-HT2CR agonist has been in development for the treatment of schizophrenia and obesity, but was stopped. As is common, there is potential for further indications for 5-HT2CR ligands, as suggested by a number of preclinical and/or genome-wide association studies (GWAS) on depression, suicide, sexual dysfunction, addictions and obesity. The 5-HT2CR is clearly affected by a number of established antidepressants/antipsychotics and may be one of the culprits in antipsychotic-induced weight gain

A multi-element psychosocial intervention for early psychosis (GET UP PIANO TRIAL) conducted in a catchment area of 10 million inhabitants: study protocol for a pragmatic cluster randomized controlled trial

Multi-element interventions for first-episode psychosis (FEP) are promising, but have mostly been conducted in non-epidemiologically representative samples, thereby raising the risk of underestimating the complexities involved in treating FEP in 'real-world' services

Etude de la pellicule d'alteration formee en surface des verres LaYSiAlO et CeYSiAlO par ERDA et RBS

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Characterization of the alteration products formed at the surface of LaYSiAlO and CeYSiAlO glasses using ERDA and RBS techniques

ACELeaching tests have been performed on LnYSiAlO glasses (Ln = La or Ce) that are considered as potential matrices for the specific immobilization of minor actinides. Elastic recoil detection analysis (ERDA) performed on leached samples indicated a superficial hydration of LaYSiAlO glass of about 100–150 nm. This hydrated layer is (Al, Y)-enriched according to SEM-EDS analysis, suggesting the formation of hydroxide (or hydroxycarbonates) compounds including these two elements. This process leads to a very efficient passivation of the material due to the low solubility of Al and Y hydroxides (and hydroxycarbonates) species in near neutral media, even when the solution is rapidly replenished is dynamic leaching experiments. Rutherford Backscattering Spectrometry elemental mapping revealed very localized and significantly Y-enriched deposits at the surface of the sample after leaching. This could be the sign of heterogeneities already present on the pristine glass. These may be correlated with the weak solubility of yttrium (and rare earth) elements in silicate matrices (Y + Ln initial content in the glass ≈11 at.%). In the case of CeYSiAlO glass, a thin layer was formed on the solid after leaching. The simulation of the corresponding RBS spectra showed a surface (Y, Ce)-enrichment and (Al, Si)-depletion in both cases. This could be explained by the oxidation of trivalent cerium initially present in the glass structure during leaching. This might be explained by the low solubility of Ce(IV)-compounds (CeO2 and/or Ce(OH)4) in solution leading to an enrichment of this element at the glass/solution interface, to form a mixture of amorphous CeO2 and Y(OH)3, as confirmed by XPS and XRD experiments

Dissolution of LnYSiAlO glass (Ln=La or Ce) in aqueous media. I. Influence of the pH on hydrolysis mechanisms and kinetics

ACEStatic leaching tests have been performed on LnYSiAlO glasses (Ln=Lanthanide: La or Ce) that are considered as potential matrices for the specific immobilization of minor actinides. The influence of the nature of the rare earth on alteration mechanisms and kinetics is studied by synthesizing two analogous compositions with lanthanum or cerium. Four series of leaching tests have been carried out for different initial pH values ranged between 1 and 13 (HNO$_3$ and NaOH dilute media, $T=90^\circ$ and $S/V$=0.06 cm$^{−1}$). For acid pH around 1–2, Al and Y + Ln are released and the formation of a non-protective Si-rich layer (a few μm thick) at the glass/solution interface is observed. On the other hand, this family of glass presents a strong chemical resistance for slightly acid and basic pH media. This property is linked to the formation of a surface protective layer that includes Al or Ln + Y hydroxides (or oxides) depending on the Ln nature and the solubility of these compounds at the considered pH. In the case of LaYSiAlO glass where only La(III) is stable, the solubility of these secondary phases is the parameter probably controlling the dissolution through the formation of a very thin passivating surface layer. This property is quite interesting in the perspective of a storage in clay or granitic medium, where flowing natural waters present a slightly basic pH. In the case of CeY glass, the possible oxidation of Ce(III) to Ce(IV) during leaching leads to a thicker surface layer, probably CeO$_2$. At the same time, an increase of the initially near-neutral pH is observed, and a preferential release of Al and Si elements occurs

Erratum to ‘Dissolution of LnYSiAlO glass (Ln=La or Ce) in aqueous media. I. Influence of the pH on hydrolysis mechanisms and kinetics'

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