Monteil M.,University of Paris 13 |
Lecouvey M.,University of Paris 13 |
Landy D.,ULCO |
Ruellan S.,ULCO |
Carbohydrate Polymers | Year: 2017
Bisphosphonates are well established pharmaceutical drugs with wide applications in medicine. Nevertheless, the side chain and the nature of phosphorous groups could induce a poor aqueous solubility and act on their bioavailability. At the same time, cyclodextrins are cage molecules that facilitate transport of hydrophobic molecules to enhance the intestinal drug absorption of these molecules by forming inclusion complexes. Here we demonstrate that cyclodextrins could be used as a bisphosphonate carrier. The formation of cyclodextrins-bisphosphonate complexes was characterized by 1D and 2D NMR spectroscopy, Isothermal Titration Calorimetry and UV–vis spectroscopy. The results revealed that only the side chain of bisphosphonate was involved in the inclusion phenomenon and its length was a crucial parameter in the control of affinity. Findings from this study suggest that cyclodextrin will be a useful carrier for bisphosphonates. © 2016 Elsevier Ltd
PubMed | Laboratoire Of Pharmacochimie, Polytechnic of Milan, ULCO, CNR Institute of Chemistry of Molecular Recognition and University of Milan
Type: | Journal: Beilstein journal of organic chemistry | Year: 2016
The polymerization of partially methylated -cyclodextrin (CRYSMEB) with epichlorohydrin was carried out in the presence of a known amount of toluene as imprinting agent. Three different preparations (D1, D2 and D3) of imprinted polymers were obtained and characterized by solid-state (13)C NMR spectroscopy under cross-polarization magic angle spinning (CP-MAS) conditions. The polymers were prepared by using the same synthetic conditions but with different molar ratios of imprinting agent/monomer, leading to morphologically equivalent materials but with different absorption properties. The main purpose of the work was to find a suitable spectroscopic descriptor accounting for the different imprinting process in three homogeneous polymeric networks. The polymers were characterized by studying the kinetics of the cross-polarization process. This approach is based on variable contact time CP-MAS spectra, referred to as VCP-MAS. The analysis of the VCP-MAS spectra provided two relaxation parameters: T CH (the CP time constant) and T 1 (the proton spin-lattice relaxation time in the rotating frame). The results and the analysis presented in the paper pointed out that T CH is sensitive to the imprinting process, showing variations related to the toluene/cyclodextrin molar ratio used for the preparation of the materials. Conversely, the observed values of T 1 did not show dramatic variations with the imprinting protocol, but rather confirmed that the three polymers are morphologically similar. Thus the combined use of T CH and T 1 can be helpful for the characterization and fine tuning of imprinted polymeric matrices.
Koubbi P.,CNRS Oceanography Laboratory of Villefranche |
Moteki M.,Tokyo University of Marine Science and Technology |
Duhamel G.,MNHN |
Goarant A.,CNRS Oceanography Laboratory of Villefranche |
And 6 more authors.
Deep-Sea Research Part II: Topical Studies in Oceanography | Year: 2011
The Southern Ocean is delimited by major frontal zones which influence pelagic life at the spatial macroscale. There is a sharp ecological segregation of pelagic fish that inhabit this ocean with some families living in the neritic zone and others in the oceanic zone. The neritic zone is dominated by fish of the Notothenioid suborder. In the oceanic zone, mesopelagic species are dominated by myctophids. Their spatial distribution is highly influenced by meso- or sub-mesoscale oceanographic features. Myctophid presence/absence records from historical surveys and from the Census of Antarctic Marine Life were used to model species assemblages in the Indian sector of the Southern Ocean by using generalized dissimilarity modeling. This statistical technique is data-driven and is used in conjunction with Geographic Information Systems for creating models between communities and environmental factors. Application of these models in large unsurveyed areas is possible and helps in delineating regions of potential similar assemblages. This will allow us to move from the bioregionalization of the Southern Ocean based on only abiotic factors and chlorophyll, to its ecoregionalization by adding species assemblages. © 2010.
Ltaief O.O.,Ad Energy |
Siffert S.,ULCO |
Fourmentin S.,ULCO |
Benzina M.,Ad Energy
Comptes Rendus Chimie | Year: 2015
In this study, a faujasite type zeolite synthesized from cheap local Tunisian illitic clay and having a hierarchical porosity was used for adsorption of heavy metals. The adsorption behavior of the FAU with respect to Cu (II), Cr (III) and Co (II) has been investigated using batch experiments. The removal efficiency was determined at different contact times, initial metal concentrations, temperatures, pHs, and adsorbent amounts. Both Langmuir and Freundlich isotherms fit well with the equilibrium data. Kinetic studies showed that the adsorption followed a pseudo-second-order model. The observed selectivity was determined as follow: Cu (II). >. Co (II). >. Cr (III). Une zéolite de type faujasite ayant une porosité hiérarchisée a été synthétisée à partir d'une argile tunisienne. Les capacités d'adsorption de cette zéolite ont été évaluées vis-à-vis de la rétention de métaux lourds: Cu (II), Cr (III) et Co (II). L'influence de divers paramètres tels que le temps, la concentration, la température, le pH et la quantité d'adsorbant a été étudiée. Les résultats obtenus ont montré que les modèles de Langmuir et Freundlich décrivaient bien l'adsorption des métaux étudiés et que l'adsorption suivait un modèle cinétique du deuxième ordre. La sélectivité observée suit l'ordre: Cu (II). >. Co (II). >. Cr (III). © 2015 Académie des sciences.
Hequette A.,University of Lille Nord de France |
Hequette A.,Laboratoire Doceanologie Et Of Geosciences Log |
Hequette A.,CNRS Laboratory of Oceanology and Geosciences |
Continental Shelf Research | Year: 2010
Analyses of shoreline and bathymetry change near Calais, northern coast of France, showed that shoreline evolution during the 20th century was strongly related with shoreface and nearshore bathymetry variations. Coastal erosion generally corresponds to areas of nearshore seabed lowering while shoreline progradation is essentially associated with areas of seafloor aggradation, notably east of Calais where an extensive sand flat experienced seaward shoreline displacement up to more than 300m between 1949 and 2000. Mapping of bathymetry changes since 1911 revealed that significant variation in nearshore morphology was caused by the onshore and alongshore migration of a prominent tidal sand bank that eventually welded to the shore. Comparison of bathymetry data showed that the volume of the bank increased by about 10×107m3 during the 20th century, indicating that the bank was acting as a sediment sink for some of the sand transiting alongshore in the coastal zone. Several lines of evidence show that the bank also represented a major sediment source for the prograding tidal flat, supplying significant amounts of sand to the accreting upper beach. Simulation of wave propagation using the SWAN wave model (Booij et al., 1999) suggests that the onshore movement of the sand bank resulted in a decrease of wave energy in the nearshore zone, leading to more dissipative conditions. Such conditions would have increased nearshore sediment supply, favoring aeolian dune development on the upper beach and shoreline progradation. Our results suggest that the onshore migration of nearshore sand banks may represent one of the most important, and possibly the primary mechanism responsible for supplying marine sand to beaches and coastal dunes in this macrotidal coastal environment. © 2010 Elsevier Ltd.
Genty E.,ULCO |
Brunet J.,ULCO |
Pequeux R.,ULCO |
Capelle S.,ULCO |
And 2 more authors.
Materials Today: Proceedings | Year: 2016
Co6Al2-yCeyHT hydrotalcite like compounds were synthesized by co-precipitation method. Hydrotalcite structure as well as the mixed oxides obtained after calcination were studied by several physic-chemical techniques: N2-Sorption, XRD, H2-TPR. The mixed oxides were also tested for the toluene total oxidation. The physico-chemical studies revealed modifications in the structural characteristics (surface area, morphology) as well as in reducibility properties of the formed mixed oxides. The solid containing the higher cerium content was the most active in this reaction. Furthermore, relation between the reducibility and T50 for the toluene oxidation was demonstrated, suggesting a Mars Van Krevelen mechanism for the toluene total oxidation with Co-Al mixed oxide. The key factor of these solids is the dispersion of the ceria in the solid. © 2016 Elsevier Ltd.
Yahi H.,ULCO |
Santer R.,ULCO |
Weill A.,LATMOS |
Crepon M.,LOCEAN |
Atmospheric Environment | Year: 2011
We present a method for retrieving atmospheric particulate matter (PM10) from sun-sky photometer measurements (AOT). As PM10 is a " surface parameter" and AOT is an " integrated parameters" , we first determined whether a " functional relationship" linking these two quantities exists. Since these two parameters strongly depend on atmospheric structures and meteorological variables, we classified the meteorological situations in terms of weather types by using a neuronal classifier (Self organizing Map). For each weather type, we found that a relationship between AOT and PM10 can be established.We applied this approach to the Lille region (France) for the summer 2007 and then extended to a five summer period (summers of the years 2003-2007) in order to increase the statistical confidence of the PM10 retrieval from AOT measurements. The good performances of the method led us to envisage the possibility of deriving the PM10 from satellite observations. © 2011 Elsevier Ltd.
Drira R.,RIADI Laboratory |
Laroussi M.,RIADI Laboratory |
Le Pallec X.,LIFL Laboratory |
IEEE Transactions on Learning Technologies | Year: 2012
In this paper, we first demonstrate that an instructional design process of Technology Enhanced Learning (TEL) systems based on a Model Driven Approach (MDA) addresses the limits of Learning Technology Standards (LTS), such as SCORM and IMS-LD. Although these standards ensure the interoperability of TEL systems across different Learning Management Systems (LMS), they are generic and lack expressiveness. In addition, the use of LTS limits designers to using a compliant LMS. MDA addresses these limits by allowing pedagogic modeling based on specific modeling languages and by ensuring interoperability across Learning Management Systems based on model transformations. In the context of an MDA-based design process, we propose a novel approach, named ACoMoD, to help designers to bridge the gap between pedagogic modeling and LMS specifications, based on graphic and interactive model transformations. Our approach, implemented with a tool called Gen-COM, enables designers to choose more effective LMS tools, based on a contextual recommendation of best practice for LMS tool use. Gen-COM and its evaluation with designers are described in this paper. The main results show, first, the usefulness of tailoring pedagogy with LMS tools based on the proposed solution. Second, the results show different levels of usefulness of the proposed assistance according to different situations that will be detailed. Some improvements are suggested and are in progress concerning the extension of Gen-COM to offer assistance to designers based on their profiles. © 2008-2011 IEEE.
PubMed | University of Paris 13 and ULCO
Type: | Journal: Carbohydrate polymers | Year: 2016
Bisphosphonates are well established pharmaceutical drugs with wide applications in medicine. Nevertheless, the side chain and the nature of phosphorous groups could induce a poor aqueous solubility and act on their bioavailability. At the same time, cyclodextrins are cage molecules that facilitate transport of hydrophobic molecules to enhance the intestinal drug absorption of these molecules by forming inclusion complexes. Here we demonstrate that cyclodextrins could be used as a bisphosphonate carrier. The formation of cyclodextrins-bisphosphonate complexes was characterized by 1D and 2D NMR spectroscopy, Isothermal Titration Calorimetry and UV-vis spectroscopy. The results revealed that only the side chain of bisphosphonate was involved in the inclusion phenomenon and its length was a crucial parameter in the control of affinity. Findings from this study suggest that cyclodextrin will be a useful carrier for bisphosphonates.
PubMed | ULCO and University Paris Diderot
Type: Journal Article | Journal: Electrophoresis | Year: 2015
One challenging point in analyzing cellular secretome collected as conditioned medium is cross-contamination by cell culture media components, especially bovine serum proteins. A common approach for serum removal is to wash the cells, an alternative is to grow cells using serum-free conditions. Given that the sample processing may influence the phenotype of cells and thus the secretome, it is important to establish the optimal protocol for each cell type. In this study, we compared two methods for preparing conditioned medium from human adipocytes derived from mesenchymal stem cells. Cells were either washed twice with PBS or cultured the last four days of differentiation in serum-free adipogenic medium. Gene expression of the cells was evaluated by using real-time PCR and 1D LC-MS/MS was used to compare secreted proteins present in the culture supernatants. Surprisingly, results showed significant differences in gene expression patterns of the cells and in protein content of the conditioned media and suggested that PBS washes induced severe modifications of the phenotype of cells and thus changes in protein secretion profiles. These data emphasize the significant variations in protein species related to cell manipulations and underline the importance of procedure optimization prior to any proteomic investigation.