Efficient synthesis of small-sized phosphonated dendrons: potential organic coatings of iron oxide nanoparticles:

We report herein the synthesis of biocompatible small-sized phosphonated monomers and dendrons used as functional coatings of metal oxide nanoparticles, more specifically superparamagnetic iron oxides (SPIOs) for magnetic resonance imaging (MRI) and therapy through hyperthermia. The molecules were engineered to modulate their size, their hydrophilic and/or biocompatible character (poly(amido) amine versus oligoethyleneglycol), the number of anchoring phosphonate groups (monophosphonate versus phosphonic tweezers) and the number of peripheral functional groups for further grafting of dyes or specific vectors. Such a library of hydrophilic phosphonic acids opens new possibilities for the investigation of dendronized nanohybrids as theranostics

Critical working tasks and determinants of exposure to bioaerosols and MVOC at composting facilities

International audienc

Development of a fast method of mineralization for routine analysis of matrix of the agricultural production

International audienc

Decrease of hydrogen incorporation in forsterite from CO2-H2O-rich kimberlitic liquid

International audienceTo test if hydrogen incorporation by ionic diffusion can occur between a volatile-rich kimberlitic liquid and forsterite, results of high-pressure and high-temperature experiments using a piston-cylinder apparatus at 1200–1300 °C and 1 GPa for durations of 1 min, 5 h, and 23 h, are reported here. Kimberlitic liquid in the system CaO-MgO-Al2O3-SiO2-CO2-H2O and synthetic forsterite single crystals were chosen as a first simplification of the complex natural kimberlite composition. Unpolarized Fourier transform infrared spectroscopy was used to quantify the concentrations of OH in the crystallographically oriented forsterite. Scanning electron microscopy, electron backscattered diffraction, electron microprobe analyses, and transmission electron microscopy were performed to identify the run products. After 5 and 23 h, a forsterite overgrowth crystallized with the same orientation as the initial forsterite single crystal. The kimberlitic liquid has crystallized as micrometer-scale euhedral forsterite neocrystals with random crystallographic orientations, as well as a nanoscale aluminous phase and a calcic phase. Despite theoretical water-saturation of the system and long duration, none of the initial forsterite single crystals display signs of hydration such as hydrogen diffusion profile from the border toward the center of the crystal. Most likely, the presence of CO2 in the system has lowered the H2O fugacity to such an extent that there is no significant hydration of the starting forsterite single crystal or its overgrowth. Also, the presence of CO2 enhances rapid forsterite crystal growth. Forsterite growth rate is around 2 × 108 μm3/h at 1250 °C. These experimental results suggest a deep mantle origin of the high OH content found in natural mantle-derived xenoliths transported in kimberlites, as reported from the Kaapvaal craton. In agreement with previous studies, it also points out to the fact that significant hydration must take place in a CO2-poor environment

Development of a fast method of mineralization for routine analysis of matrix of the agricultural production

International audienc

Gq-coupled Purinergic Receptors Inhibit Insulin-like Growth Factor-I/Phosphoinositide 3-Kinase Pathway-dependent Keratinocyte Migration

After skin wound, released growth factors and extracellular nucleotides regulate the different phases of healing, including re-epithelialization. Here, we show that, in keratinocytes, purinergic P2Y2 receptors inhibit the motogenic IGF-I/PI3K pathway. Therefore, extracellular nucleotides may play key roles during skin remodelling after wound

A bisphosphonate tweezers and clickable PEGylated PAMAM dendrons for the preparation of functional iron oxide nanoparticles displaying renal and hepatobiliary elimination

International audienceThe functionalization of superparamagnetic iron oxide nanoparticles (SPION) with PEGylated PAMAM dendrons through a bisphosphonate tweezers yielded 15 and 30 nm dendritic nano-objects stable in physiological media and showing both renal and hepatobiliary elimination

Indoor air quality improvement and energy cost of central ventilation air cleaning systems

International audienc

Étude des polluants atmosphériques émis dans deux centres de stockage des ordures ménagères

International audienceWe have a lack of knowledge about the existence of risks for the health related with domestic garbage elimination in municipal solid waste landfills. In the aim of obtaining more data, a multidisciplinary approach has been developed and applied to two sites:- chemical and microbiological metrology of sources;- metrology of selected pollutants and microorganism analysis in the ambient air at several places of work, as well as in immediate periphery and close to the first dwellings;- measure of these pollutants in lichens;- experimental survey in laboratory of rats living on landfill soils;- survey of health parameters in workers of the sites compared to non exposed men employed in other commercial of industrial activities.In fact, concentrations of pollutants are low, with the exception of total dusts, manganese and microorganisms. The volatile organic compounds (VOC) are present on the celle in operation, because of the traffic of diesel trucks. The same observation is done for PAH, which are closed to the urban environment levels. High total dusts levels have been measured (but the levels of alveolar dusts were low). Manganese is the more representative metal, which is also recovered in lichens. Concentrations of microorganisms are high (100 at 1000 times what one recovers in classic environment), with the presence of pollution picks, and characteristic monomorphic bacteria and fungi (Aspergillus and Penicillium).Respiratory symptoms and cutaneous irritation are more often observed among landfill workers than among non-exposed workers, but no perturbation of the lung function was detected among them. Studies led on laboratory rats showed the existence of inflammation of the pulmonary tissues. Enzymatic induction (CYP1A and CYP2B) in respiratory and hepatic cells was observed. Observations of comets indicate a transient aggression, which was compatible with inhalation of COV.This study brings several elements of knowledge on the ambient air pollution in municipal solid waste landfill, and their possible effects on health. It would be necessary to continue the investigations particularly on the sanitary effect of the microbiological pollution.L’existence de risques pour la santé associés à l’élimination des ordures ménagères en décharge contrôlée est encore mal évaluée. Devant les données très parcellaires dont on dispose, une approche pluridisciplinaire établie en plusieurs étapes a été conçue par le Réseau Santé Déchets (RSD) et appliquée à deux sites :- métrologie chimique et microbiologique des sources d’émission ;- métrologie des polluants sélectionnés et des microorganismes aux postes de travail et en ambiance, ainsi qu’en périphérie immédiate et à proximité des premières habitations ;- mesure de ces mêmes polluants dans les lichens présents sur les sites ou transplantés ;- étude expérimentale en laboratoire sur des rats au contact des sols prélevés sur les deux sites ;- étude des paramètres de santé et de l’existence ou non de troubles chez les salariés des sites comparés à des salariés non exposés issus d’autres activités.Les concentrations mesurées dans les ambiances aériennes des sites et à proximité sont dans l’ensemble faibles.Les composés organiques volatils (COV) sont présents, à des niveaux faibles, sur l'alvéole en exploitation, liés en particulier au trafic des engins diesel. Les niveaux de HAP particulaires sont de l'ordre de ceux qui sont observés en milieu urbain. Des niveaux très élevés en poussières totales (mais faibles pour les poussières alvéolaires) ont été mesurés. Le manganèse est le métal le plus représenté, il est retrouvé également dans les lichens. Les concentrations en micro-organisme sont élevées soit 100 à 1000 fois ce que l'on retrouve en environnement classique. La flore est caractéristique des milieux de traitement du déchet avec un aspect monomorphe (champignons de type Aspergillus ou Penicillium).Une symptomatologie fonctionnelle témoignant d'une atteinte irritative ou immunoallergique des voies respiratoires et du revêtement cutanéo-muqueux est observée chez les salariés des sites étudiés, sans qu'il n'y ait perturbation de la fonction respiratoire. Aucun trouble clinique n'est mis en évidence. Les études menées sur les rats de laboratoire ont montré l'existence de foyers inflammatoires des tissus pulmonaires (chez les bêtes autopsiées) et d'une réponse en terme d'induction enzymatique (CYP1A et CYP2B) surtout respiratoire. Le test génotoxique des comètes indique une atteinte transitoire et compatible avec l'inhalation de COV.Cette étude, même si elle ne représente qu'un instantané de la situation des deux sites étudiés, apporte les premiers éléments de connaissance sur les effluents aériens de décharges d'ordures ménagères, et leurs possibles effets sur la santé. Elle ouvre sur des questions qu'il faudrait pouvoir approfondir, en particulier l'impact sanitaire des micro-organismes