Journals
2009 EN
R. Carta · Philippe Jourand · Bart Hermans
+7 more
This paper presents the design and implementation of an advanced system on flexible and stretchable technology. The technology platform consists of a matrix of flexible non-stretchable functional islands linked together by a net of elastic interconnections. Several technologies have been developed and tested in the design of simplified demonstrators before studying the design of an advanced system. The target system is a wireless battery charger which supplies power and supports bidirectional data transfer during recharge. The system is intended to serve as a general purpose platform for biomedical parameter monitoring and the design is focused on the embedding in clothes.status: publishe
Journals
2009 EN
Michaël Josse · O. Bidault · F. Roulland
+6 more
24 pages, 8 figures, 2 tablesInternational audienceSeveral Niobium oxides of formula Ba_2LnFeNb_4O_{15} (Ln = La, Pr, Nd, Sm, Eu, Gd) with the Tetragonal Tungsten Bronze (TTB) structure have been synthesised by conventional solid-state methods. The Neodymium, Samarium and Europium compounds are ferroelectric with Curie temperature ranging from 320 to 440K. The Praseodymium and Gadolinium compound behave as relaxors below 170 and 300 K respectively. The high temperature magnetic susceptibility of the Praseodymium, Neodymium, Samarium, Europium and Gadolinium compounds indicate that they are ferro or ferrimagnetically ordered below Curie temperatures ranging from 680 to 720K. Both ferroelectric and magnetic hysteresis loops are reported at room temperature, thus confirming the multiferroic behaviour of these compounds. Crystal-chemical analysis suggests a close relationship between the distortion of the TTB framework induced by the rare earth and the multiferroic properties
Journals
2009 EN
Olivier Danot · Emélie Marquenet · Dominique Vidal-Ingigliardi
+1 more
The signal transduction ATPases with numerous domains (STAND) represent a newly recognized class of widespread, sophisticated ATPases that are related to the AAA+ proteins and that function as signaling hubs. These proteins control diverse biological processes in bacteria and eukaryotes, including gene expression, apoptosis, and innate immunity responses. They function as tightly regulated switches, with the off and on positions corresponding to a long-lived monomeric, ADP-bound form and a multimeric, ATP-bound form, respectively. Inducer binding to the sensor domain activates the protein by promoting ADP for ATP exchange, probably through removal of an intramolecular inhibitory interaction, whereas ATP hydrolysis turns off the protein. One key component of the switch is a three-domain module carrying the ATPase activity (nucleotide-binding oligomerization domain [NOD]). Analysis of the atomic structures of four crystallized nucleotide-bound NOD modules provides an unprecedented insight into the NOD conformational changes underlying the activation process.
Journals
2009 EN
Dominique Bourgeois
In this issue of Structure, Knapp et al. show that allosteric changes in dimeric hemoglobin are retarded in the crystal, using time-resolved Laue diffraction. They observe that photo-dissociated carbon monoxide, after exploring a web of cavities, rebinds to the heme before it has a chance to exit the protein
Journals
2009 EN
Federico Carafoli · Dominique Bihan · Stavros Stathopoulos
+5 more
The discoidin domain receptors, DDR1 and DDR2, are widely expressed receptor tyrosine kinases that are activated by triple-helical collagen. They control important aspects of cell behavior and are dysregulated in several human diseases. The major DDR2-binding site in collagens I-III is a GVMGFO motif (O is hydroxyproline) that also binds the matricellular protein SPARC. We have determined the crystal structure of the discoidin domain of human DDR2 bound to a triple-helical collagen peptide. The GVMGFO motifs of two collagen chains are recognized by an amphiphilic pocket delimited by a functionally critical tryptophan residue and a buried salt bridge. Collagen binding results in structural changes of DDR2 surface loops that may be linked to the process of receptor activation. A comparison of the GVMGFO-binding sites of DDR2 and SPARC reveals a striking case of convergent evolution in collagen recognition.
Journals
2009 EN
Ingrid C. McCall · Abigail Betanzos · Dominique A. Weber
+3 more
Phenol contamination of soil and water has raised concerns among people living near phenol-producing factories and hazardous waste sites containing the chemical. Phenol, particularly in high concentrations, is an irritating and corrosive substance, making mucosal membranes targets of toxicity in humans. However, few data on the effects of phenol after oral exposure exist. We used an in vitro model employing human intestinal epithelial cells (SK-CO15) cultured on permeable supports to examine effects of phenol on epithelial barrier function. We hypothesized that phenol disrupts epithelial barrier by altering tight junction (TJ) protein expression. The dose-response effect of phenol on epithelial barrier function was determined using transepithelial electrical resistance (TER) and FITC-dextran permeability measurements. We studied phenol-induced changes in cell morphology and expression of several tight junction proteins by immunofluorescence and Western blot analysis. Effects on cell viability were assessed by MTT, Trypan blue, propidium iodide and TUNEL staining. Exposure to phenol resulted in decreased TER and increased paracellular flux of FITC-dextran in a dose-dependent manner. Delocalization of claudin-1 and ZO-1 from TJs to cytosol correlated with the observed increase in permeability after phenol treatment. Additionally, the decrease in TER correlated with changes in the distribution of a membrane raft marker, suggesting phenol-mediated effects on membrane fluidity. Such observations were independent of effects of phenol on cell viability as enhanced permeability occurred at doses of phenol that did not cause cell death. Overall, these findings suggest that phenol may affect transiently the lipid bilayer of the cell membrane, thus destabilizing TJ-containing microdomains.
Journals
2009 EN
Hideyuki Arata · Frédéric Gillot · Dominique Collard
+1 more
Study of interaction between DNA and intercalator at molecular level is important to understand the mechanisms of DNA replication and repair. A micro-fabricated local heating thermodevice was adapted to perform denaturation experiments of DNA with fluorescent intercalator on millisecond time scale. Response time of complete unzipping of double stranded DNA, 16 microm in length, was measured to be around 5 min by commercial thermocycler. Response time of quenching of double stranded DNA with fluorescent intercalator SYBR Green was measured to be 10 ms. Thus, quenching properties owing to strand unzipping and denaturation at base pair level were distinguished. This method has provided easy access to measure this parameter and may be a powerful methodology in analyzing biomolecules on millisecond time scale.
Journals
2009 EN
Valérie Leroy · Dominique Cancellieri · Eric Leoni
+1 more
International audienceThe kinetics of thermal decomposition of a forest fuel was studied by thermogravimetry. Experiments were monitored under air and non-isothermal conditions from 400 to 900 K. We used a classical modelfree method, the Kissinger-Akahira-Sunose (KAS) method to calculate the activation energy vs. the conversion degree of the reaction on the whole temperature domain. Analyses were performed at 10, 20 and 30 K/min. As expected, the complex structure of lignocellulosic fuels involved several steps with different energies in the degradation processes. The algorithm developed here, allows the calculation and the simulation of the solid temperature at different conversion degree for various heating rates. The good correlation between experiments and simulations validated the proposed algorithm. Then, kinetics parameters were used to perform simulations up to heating rates outside the functioning range of the thermal analyser
Journals
2009 EN
Dominique Foata · Guo-Niu Han
A new coding for permutations is explicitly constructed and its association with the classical Lehmer coding provides a bijection of the symmetric group onto itself serving to show that six bivariable set-valued statistics are equidistributed on that group. This extends a recent result due to Cori valid for integer-valued statistics
Journals
2009 EN
Marie-Pierre Béal · Dominique Perrin
We define a code in a sofic shift as a set of blocks of symbols of the shift such that any block of the shift has at most one decomposition into code words. It is maximal if it is not strictly included in another one. Such a code is complete in the sofic shift if any block of the shift occurs within some concatenation of code words. We prove that a maximal code in an irreducible sofic shift is complete in this shift. We give an explicit construction of a regular completion of a regular code in a sofic shift. This extends the well known result of Ehrenfeucht and Rozenberg to the case of codes in sofic systems. We also give a combinatorial proof of a result concerning the polynomial of a code in a sofic shift