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Abstract: The large ring cyclodextrins (with more than 8 glucose units) existence was first described in the 1950s. Because of their hard purification and low yield, these molecules were little studied until recently. Since large ring cyclodextrins have unique structures compared to α-, β- and γ-cyclodextrin, they could offer new opportunities for specific host-guest complex and thus enlarge the area of cyclodextrin applications. This paper gives a literature survey regarding the synthesis, the purification and the applications of cyclodextrins containing more than eight glucose units. [Copyright &y& Elsevier]

Abstract: Feasibility study of a new water-softening household process by means of ions exchange. Throughout the world, many hydric resources are made up of waters rich in calcium and magnesium called hard waters. Several processes, such as acid vaccination, membrane techniques, are used to reduce the water hardness, as the most used and effective process is the one that uses resins exchanging ions, with sodium ions permutation on sulfonic resin. This paper focuses on the feasibility of a new household ion-exchange process. The resin used was a carboxylic resin with ions H+ permutation, the interest of such a technique being to ensure the calcium carbonate elimination instead of its replacement by sodium carbonate. The exchange capacity and the exchange constant of this resin were determined. The resin was saturated with a 30°F calcic hardness water and regenerated by a 2 mol l–1 citric acid solution. The feasibility of a household ion-exchange process, using citric acid as a regenerating agent, was thus demonstrated. To cite this article: M.A. Dia et al., C. R. Chimie 9 (2006) . [Copyright &y& Elsevier]

Abstract: Interest in coupling membranes autopsies and permeates analysis for a better management of fouling phenomena occuring in low-pressure MF/UF membranes. Successful utilization of membrane technology has been greatly limited by membrane fouling. Fouling increases operation and maintenance costs by deteriorating membrane performance (flux decline vs time) and ultimately shortening membrane life. Natural organic matter (NOM) plays an important role in membrane fouling. Humic substances as well as polysaccharides and proteins have been shown to exert fouling properties towards low- and high-pressure membranes. The overall objective of our work is to better characterize the nature of the fouling material, which is responsible for the reduction of permeability observed during low-pressure membrane filtration (MF and UF) of raw and chemically treated surface waters using hollow fiber modules. Our paper focused on the membrane caracterizations conducted on hollow fibers operated with a raw surface water and two synthetic solutions containing models foulants (humic acids and algal culture) using a large panel of analytical tools including novel technologies such as ESCA (Electron Spectroscopy for Chemical Analysis) and pyrolysis gaz chromatography/mass spectrometry in addition to FESEM (Field Emission Gun Scanning Electronic Microscopy), AFM (Atomic Force Microscopy), contact angle and zeta potential measurements. Complementary informations obtained from the analyses of the feed water, the permeate and the backwash water solution (DOC, UV254, High-pressure SEC, Total Amino Acids (AA) and Amino Sugar (AS), hardness, alkalinity) are also discussed. Furthermore, the cake layer model of fouling is developped to determine the modified fouling index parameters denoted MFI-UF and MFI-MF for a raw water from the Marne River (France) and two synthetics solutions (humics and algae), in order to predict fouling. To cite this article: K. Kecili et al., C. R. Chimie 9 (2006) . [Copyright &y& Elsevier]

Abstract: Akt (PKB) plays a central role in the regulation of cellular antiapoptosis and, thus, is a core intracellular survival factor underlying various human neoplastic diseases. Hence, Akt specific inhibitors create an attractive target for anticancer therapy. We have previously demonstrated that proteins of the TCL1 family (a protooncogene underlying human T cell prolymphocytic leukemia) interact with Akt and functions as Akt kinase coactivators. TCL1 coactivate Akt by binding to its pleckstrin homology domain (Akt-PHD). Then, with the aim to develop an Akt kinase inhibitor, we have hypothesized and verified that a peptide, which spans the Akt binding site (the A β-strand of human TCL1), binds to Akt and modulates Akt kinase activity and its downstream biological responses. Nuclear magnetic studies suggested that Akt_in shares a similar binding site with TCL1, but causes remote conformational changes on the variable loop 1 of the PH domain, the locus mediating phosphoinositide binding. In the present paper, we used NMR titration experiments to demonstrate that the binding of Akt-in to Akt-PHD significantly decreases the affinity of the PH domain for IP4, the sugar headgroup of phosphatidyl-inositol phosphate lipids, responsible for the membrane anchorage of the kinase and its subsequent activation. To cite this article: V. Ropars et al., C. R. Chimie 9 (2006) . [Copyright &y& Elsevier]

Inorganic fluorides: model materials to investigate NMR parameters calculation methods (chemical shift and quadrupolar parameters). In this paper, NMR parameters calculation methods applied to crystallized and/or disordered inorganic fluorides are presented: 19F isotropic chemical shift, and 23Na, 27Al, 69,71Ga quadrupolar parameters. These values were obtained using semi-empirical or ab initio calculations, whose principles are presented. The results are generally in good agreement with the experimental values. To cite this article: G. Silly et al., C. R. Chimie 7 (2004). [Copyright &y& Elsevier]

The characterisation of the surface electrical properties of membrane materials is critical for understanding and predicting the filtration performances of membranes. In this paper, four simple experimental methods – streaming potential, electro-osmosis, pore conductivity and membrane potential –, allowing the characterisation of the charge state of membrane pore walls are presented. The four experimental parameters provide information about the sign of the electrical net charge. Examples illustrating the influence of the pH, electrolyte concentration and nature on the four experimental parameters are given. The zeta potential can be then deduced from these measurements by means of a model. [Copyright &y& Elsevier]