Genetic Admixture and Flavor Preferences: Androstenone Sensitivity in Malagasy Populations

The genetic basis of androstenone anosmia has been well-studied due to androstenone’s putative role as a human sex pheromone and its presence in pork meat. Polymorphisms have been identified on the olfactory receptor gene OR7D4, which significantly affect perception of androstenone pleasantness and intensity in several western populations. This study aims to investigate androstenone sensitivity and the influence of OR7D4 polymorphisms in non-western populations. Androstenone perception was tested in 132 individuals from Madagascar using a double 3-Alternative Choice test with two concentrations of androstenone (0.17 μg/ml and 1.7 μg/ml). We found that Malagasy populations described this molecule in a similar way to European populations, and 21% of the sample was not able to smell androstenone. In contrast to previous studies, there was no significant evidence of the influence of rs61729907: C\u3eT (R88W) and rs5020278: C\u3eT polymorphisms (T133M) on androstenone sensitivity in Malagasy populations. We found, however, a significant effect of the polymorphism rs61732668 (P79L), and a significant difference in androstenone perception between populations in different locations across Madagascar. This study indicates the existence of population specific factors to androstenone sensitivity, suggesting that population history has a role in shaping an individual’s smell and flavor preferences, and food preferences in general

A French multicentric prospective prognostic cohort with epidemiological, clinical, biological and treatment information to improve knowledge on lymphoma patients: study protocol of the "REal world dAta in LYmphoma and survival in adults" (REALYSA) cohort.

BACKGROUND: Age-adjusted lymphoma incidence rates continue to rise in France since the early 80's, although rates have slowed since 2010 and vary across subtypes. Recent improvements in patient survival in major lymphoma subtypes at population level raise new questions about patient outcomes (i.e. quality of life, long-term sequelae). Epidemiological studies have investigated factors related to lymphoma risk, but few have addressed the extent to which socioeconomic status, social institutional context (i.e. healthcare system), social relationships, environmental context (exposures), individual behaviours (lifestyle) or genetic determinants influence lymphoma outcomes, especially in the general population. Moreover, the knowledge of the disease behaviour mainly obtained from clinical trials data is partly biased because of patient selection. METHODS: The REALYSA ("REal world dAta in LYmphoma and Survival in Adults") study is a real-life multicentric cohort set up in French areas covered by population-based cancer registries to study the prognostic value of epidemiological, clinical and biological factors with a prospective 9-year follow-up. We aim to include 6000 patients over 4 to 5 years. Adult patients without lymphoma history and newly diagnosed with one of the following 7 lymphoma subtypes (diffuse large B-cell, follicular, marginal zone, mantle cell, Burkitt, Hodgkin, mature T-cell) are invited to participate during a medical consultation with their hematologist. Exclusion criteria are: having already received anti-lymphoma treatment (except pre-phase) and having a documented HIV infection. Patients are treated according to the standard practice in their center. Clinical data, including treatment received, are extracted from patients' medical records. Patients' risk factors exposures and other epidemiological data are obtained at baseline by filling out a questionnaire during an interview led by a clinical research assistant. Biological samples are collected at baseline and during treatment. A virtual tumor biobank is constituted for baseline tumor samples. Follow-up data, both clinical and epidemiological, are collected every 6 months in the first 3 years and every year thereafter. DISCUSSION: This cohort constitutes an innovative platform for clinical, biological, epidemiological and socio-economic research projects and provides an opportunity to improve knowledge on factors associated to outcome of lymphoma patients in real life. TRIAL REGISTRATION: 2018-A01332-53, ClinicalTrials.gov identifier: NCT03869619

Calix[4]arènes fonctionnels pour la chimie verte

Le travail présenté dans cette thèse visait à étendre le champ d applications de ligands calix[4]arèniques.La première partie de ce travail est consacrée à l utilisation en milieu aqueux ou sans solvant de bis-phosphitecalix[4]arènes hémisphériques. La transposition de réactions catalytiques à ces milieux non usuels permet d accroître l activité du catalyseur par rapport à une utilisation en milieu organique classique. Utilisés en hydroformylation d'oléfines, ces ligands conduisent sélectivement à l'aldéhyde linéaire, la régiosélectivité du système étant principalement contrôlée par les propriétés intrinsèques du ligand. De même, la réaction d hydroaminovinylation des a-oléfines catalysée par du rhodium conduit, en milieu totalement dépourvu de solvant, à des rapports produit linéaire/produit branché très élevés d énamines/amines (à partir d amines secondaires) et d imines (à partir d amines primaires). Dans les chapitres suivants, des calix[4]arènes portant un groupement PPh2 ou N=PPh2 comme seul groupe fonctionnel ont été testés en couplage croisé catalysé par du palladium et du nickel. Avec les bromures d aryle, des activités remarquablement élevées ont été obtenues. La capacité de ces ligands à catalyser efficacement les réactions de formation de liaison C-C est liée d une part à l encombrement stérique de l'entité calixarényle, mais aussi à l aptitude de ce fragment à piéger de manière supramoléculaire des entités métal-(p-arène). Ces deux propriétés sont de nature à favoriser la formation d une espèce mono-ligand M(0)L(ArX) (M = Pd, Ni), l étape d addition oxydante devenant alors plus facile à partir d une telle espèce qu à partir d une espèce M(0)L2.The aim of this work was to extend the scope of catalytic applications of ligands based on a calix[4]arene skeleton.The first part of this work focusses on new applications of hemispherical bis-phosphites calix[4]arenes in the rhodium catalysed hydroformylation of a-olefins, either in aqueous medium or under solvent-free conditions. These particular conditions resulted in enhanced activities compared to tests carried out in toluene. The ligands turned out to efficiently drive reactions towards the formation of linear products. The selectivity of the system is mainly controlled by the intrinsic properties of the ligand, which is able to tightly envelope the catalytic centre. In keeping with these observations, the application of solvent-free conditions to the rhodium-catalysed hydroaminovinylation of a-olefins resulted in high linear/branched ratios of enamines/amines (starting from secondary amines) or imines (starting from primary amines). In the following chapters, calix[4]arenes bearing a PPh2 or a N=PPh2 group as the sole functional group anchored at their upper rim were assessed in palladium or nickel-catalysed cross-coupling reactions. With arylbromides, these monodentate ligands led to remarkably high activities. The high performances probably arise from a combination of the bulkiness of the calixarenyl fragment as well as its ability to temporarely entrap metal-( 6-arene) moieties in a supramolecular fashion. Both properties favour the formation of mono-ligand intermediates M(0)L(ArX) (M = Pd, Ni), from which the following oxidative addition step is facilitated with respect to a step involving M(0)L2 species.STRASBOURG-Sc. et Techniques (674822102) / SudocSudocFranceF

Tetra-hydroxy-calix[4]arene derivatives with two P(III) or P(V) units attached at the upper rim.

International audience5,17-Bis(diphenylphosphino)-25,26,27,28-tetra-hydroxy-calix[4]arene (2) and the corresponding bis- (phosphine oxide) (3) and bis-(phosphine sulfide) (4) have been synthesized. A single crystal X-ray diffraction study was carried out for bis(phosphine oxide) 3, which revealed a pinched cone conformation for the calixarene core. In the solid state, each calixarene is linked to two other calixarenes via hydrogen bonds involving the phosphoryl groups as well as two of the four hydroxyl groups, thereby generating a supramolecular polymeric structure. Selective formation of chelate complexes from diphosphine 2 failed, probably because of rapid trans annular rotation of the phenoxyl groups that prevents appropriate ligand preorganisation. Upon reaction with appropriate Ru-, Rh-, and Ir-complexes, ligand 2 readily formed dinuclear complexes. One of them, namely the complex [2 {RhCl(1,5-cyclooctadiene)}2] was assessed in the catalytic hydrogenation of linear and cyclic olefins

Pseudo-capsular behaviour of two trans-coordinated calixarenyl phosphines

International audienceThe square-planar complex trans-[PtCl2L2] (L = 5-diphenylphosphinyl-25,26,27,28-tetrabenzyloxy-calix[4]arene) was prepared in two steps from [PtCl2(cod)] (cod = 1,5-cyclooctadiene) and the corresponding phosphine. In the solid state, the calixarene moieties adopt a typical pinched cone conformation; they are both turned towards the Cl-Pt-Cl rod, thereby forming a capsule that hosts the platinum centre

Resorcinarenyl-Phosphines in Suzuki-Miyaura CrossCoupling Reactions of Aryl Chlorides

International audienceTwo phosphines built on a bowl-shaped resorcin[4]arene skeleton, namely 5-diphenylphosphanyl- and 5-diisopropylphosphanyl-4(24),6(10),12(16),18(22)-tetramethylenedioxy-2, 8,14,20-tetrapentylresorcin[4]arene, have been synthesised and tested in the Suzuki-Miyaura cross-coupling reaction of aryl halides. Combining these ligands with [Pd(OAc)(2)] resulted in highly active catalysts that allowed the formation of o,o-biphenyls starting from aryl chlorides. The remarkable activities observed possibly arise from 1) the capacity of the phosphines to operate transiently as P,O chelators, thereby increasing the electron density of the metal, and 2) the ability of the ligands to embed metal-organic units, which, when occurring, makes the ligand considerably bulkier so as to disfavour the coordination of a second phosphine. Both features are known to facilitate the oxidative addition step

Foaming in CO2 sc medium as an efficient way to produce electromagnetic interference shielding materials

This communication reports on the preparation of novel nanocomposites foams that are efficient broadband microwave absorbers.7 Multiwalled carbon nanotubes (MWNT) are first successfully dispersed into polymer matrix by melt-blending as confirmed by TEM microscopy and rheology. Then foaming of these nanocomposites8 occurs under supercritical CO2 conditions by a two-step process.9 This physical foaming constitutes a green alternative to classical foaming agents.10 Well-defined microcellular foams11 were obtained with cell size around 10-50 μm and cellular density around 108 cells per cm3, the morphology of the foam was determined by SEM microscopy. The impact of several criteria on the morphology of the foam will be discussed. The EMI shielding efficiency of these materials are then evaluated and compared to the non-foamed nanocomposites. Finally, we will discuss about the design of the foam that is essential to optimize the performances of the EMI absorber

Supercritical CO2 and polycarbonate based nanocomposites: a critical issue for foaming

Supercritical carbon dioxide readily induced foaming of various polymers. In that context, supercritical CO2 was applied to carbon nanotubes based polycarbonate nanocomposites to ensure their foaming. Surprisingly, efficient foaming only occurs when low pressure is applied while at high pressure, no expansion of the samples was observed. This is related to the ability of supercritical carbon dioxide to induce crystallization of amorphous polycarbonate. Moreover, this behaviour is amplified by the presence of carbon nanotubes that act as nucleating agents for crystals birth. The thermal behaviour of the composites was analysed by DSC and DMA and was related to the foaming observations. The uniformity of the cellular structure was analyzed by scanning electron microscopy (SEM). By saturating the polycarbonate nanocomposites reinforced with 1 wt% of MWNTs at 100 bar and 100°C during 16h, microcellular foams were generated, with a density of 0.62, a cell size ranging from 0.6 to 4 μm, and a cellular density of 4.1.1011 cells.cm-3. The high ability of these polymeric foams to absorb electromagnetic radiation was demonstrated at low MWNT content as the result of the high affinity of the polycarbonate matrix for MWNTs, and therefore to the good MWNTs dispersion