The development of high field NMR and the continual search for optimised sensitivity have been accompanied by the observation of various new phenomena, related to the non-linear evolution of nuclear magnetisation in liquid samples. In most cases, unusual behaviours result from the intricate combination of (i) the non-linear coupling between the transverse nuclear magnetisation and the detection coil (radiation damping) and (ii) the enhanced contribution of long-range magnetic interactions, not averaged out by the Brownian motion (distant dipolar fields, DDFs). Radiation damping has become quite common due to the widespread use of improved or miniaturised probes, with high quality and high filling factors. DDF effects, difficult to observe with conventional NMR in thermally polarised systems, have recently been brought to the fore in high resolution spectroscopy. This research project aims at cooperative action for detailed investigation and better understanding of the complex non-linear NMR dynamics in highly polarised liquids. It aims at a quantitative characterisation and a comprehensive description of the spectacular effects that have been observed in dense laser polarised solutions, motivated by the growing impact of DDFs on dynamics in high field NMR, as well as in a wide range of other physical systems (such as Bose-Einstein condensates, superfluid 3He, degenerate 3He-4He mixtures, and two-dimensional atomic hydrogen gas). The joint development of new theoretical and experimental tools for efficient control of the evolution of the nuclear magnetisation is expected to lead to powerful ways to: (i) reduce the foreseen limits, set by DDF effects, to the efficiency of sophisticated pulse sequences currently at use in high resolution NMR spectroscopy, (ii) clarify recent major developments in MRI, based on DDF used as contrast agent, and (iii) take full advantage of NMR signal enhancements, recently achieved by DDF-induced transfer of nuclear polarisation from dissolved xenon to other nuclei. For more than ten years now, Paris and Saclay have independently worked on experimental and numerical investigations of DFF effects (spectral clustering, instabilities) using complementary polarised systems and approaches. Paris uses cryogenics techniques and takes advantage of the record dipolar field strengths obtained in laser polarised liquid 3He by metastability exchange optical pumping, of the wide range of diffusion coefficients reached in isotopic mixtures by temperature control or dilution in superfluid 4He, and of operation at millitesla field strengths for improved control of static field inhomogeneities. Saclay combines expertise in spin exchange optical pumping of 129Xe (using rubidium as laser pumped alkali atom) and room temperature high field spectroscopy (11.7T), taking advantage of the large chemical shift sensitivity to individually probe solute and solvent dynamics. New features of temporal evolution have recently been observed at both places. In Paris, time-reversal has been achieved and will be combined to diffusion weighting to probe growth and structure of DDF-induced magnetisation patterns. In Saclay, multiple maser emission and non-linear xenon relaxation have been observed and will be investigated using innovative high sensitivity techniques. The project also includes joint experimental and numerical work for the development of robust new pulse sequences for efficient handling of magnetisation in the presence of strong DDF and radiation damping. Finally, a new theoretical framework will be developed to better describe DDF-induced phenomena, taking into account the dynamic correlations that are overlooked in the classical description of long-range static dipolar couplings in liquids.

Fluorine gas is used in the nuclear industry to produce uranium hexafluoride, required for the enrichment of U 235. Fluorine, F2 is generated as a thin gaseous film at carbon anode by the electrolysis of molten KF,2HF, which is extremely corrosive. In order to remain competitive, COMURHEX must develop a new technology with improved energetic yield, higher productivity, less environmental impact. To succeed COMURHEX has to make several breakthroughs. SUCCEF is an industrial research project, whose objective is to develop and prepare an industrial prototype, by using new carbon/carbon composites developed by SNECMA Propulsion Solid (SPS) and machined by PIT. A frame of strong interactions with university laboratories will help the project to be successful and in particular to overcome the 3 major drawbacks of current technology: - Copper used to bring the DC current, undergoes major erosion and corrosion, which finally leads to the death of the electrolyser. To limit the degradation, a plate will be implemented under copper to protect the current providers from electrolyte movements - Up to now no materials is suitable for separating the anode and cathode compartments. As a consequence, anode and cathode are currently separated by an important distance to limit the anodic and cathodic gas recombination. Therefore, the ohmic voltage drop in the electrolyte is large (3V). The aim is to decrease drastically the ohmic drop by implementing a physical separator in carbon-carbon composite which enables ionic exchanges, avoids gas recombination and allows to move the two electrodes closer together. -The F2 generation overvoltage is extremely high (3V). The third idea is to design thinner anode materials in composite with a lower overvoltage, which will allow higher current, increased lifetime thanks to higher mechanical resistance. Such materials will be moreover easier to recycle contrary to the current carbon anodes. In this project, the following material's performances will be studied, improved: wettability, permeability, density, porosity for the separator, overvoltage, machining and the global design of the electrolyser. For these reasons four university laboratories will be implied in the project. They are specialized in testing materials in gaseous F2 (ICMCB), in wettability studies in corrosive media (LGC), in molten salt electrolysis (LI2C) and in electrical contacts (IES). This project comes within the scope of the sustainable development by not only reducing the production costs but also by treating wastes and recycling high value materials. Such technological challenges will enable COMURHEX to keep its leadership and take new foreign markets. SPS will find new applications for carbon-carbon composites in extreme media. PIT will reinforce its positions at machining carbon materials. University laboratories will improve their knowledge of extreme media, material characterizations and optimization of separator properties.

The present project is proposed by two teams. The Quantum chaos group of the Laboratoire de Physique des Lasers, Atomes et Molécules (PhLAM), at the Université des Sciences et Technlogies de Lille, has been working on experimental and theoretical studies of quantum dynamics of laser-cooled atoms for many years, especially in the helm of quantum chaos, in which it acquired an international visibility. The Dynamics of coulombian systems group of the Laboratoire Kastler-Brossel (LKB) at Ecole Normale Supérieure, has been a world leader in the theory of quantum chaos for two decades. The two teams have been fruitfully collaborating since 1999. In the present project, the PhLAM team will be mostly in charge of the experimental activities, and the LKB will be mostly responsible for modelizing and numerical simulations. - Laser-cooled atom physics has been playing a major role in atomic physics and quantum optics for twenty years of so. The importance of the subject was even increased by many important breakthroughs: the experimental observation of Bose-Einstein condensates (1995), the production of quantum-degenerate Fermi gases (1999) and the possibility of using one-atom traps for quantum information processing (2001). A relevant part of this effort concentrates in the dynamics of cold atoms (in the quantum-degenerate regime or not) trapped in optical potentials. This allowed in particular the observation of Bloch oscillations (1996), of the Wannier-Stark ladder (1996), and of the Mott transition (2002), establishing a bridge with solid-state physics. Atoms trapped in optical potentials have also been used in studies of quantum chaos and for the manipulation of q-bits . Despite these remarkable advances, most experimental observations of quantum dynamics in optical potentials are still confined to the momentum space, using either time-of-flight techniques or stimulated Raman spectroscopy. Two factors make it very difficult to observe this dynamics directly in position space. Firstly, the width of the wells in an optical potential is typically half the wave-length, forbidding a direct measurement of the position by observing the fluorescence of the atom. Secondly, one generally works with clouds or condensates made of thousands to millions of atoms whose spatial extension is of the order of a hundred microns, much larger than the typical sizes involved in quantum dynamics (which usually involves only a few neighbor wells); these effects are thus difficult to detect in the much larger atom cloud or condensate. - The present project proposes a solution to these difficulties, allowing the detection of atomic dynamics in the position space with a resolution comparable (or even better) than the width of a potential well. This shall be achieved by trapping a single atom in an optical potential and bringing it within a sub-lambda distance of a microstructured optical fiber, presenting sub-lambda structures. Such conditions shall allow us to make a near-field image of the atom, inspired from a technique that has been used for many years for sub-lambda microscopy of solids. Our initial aim is to obtain a resolution of the order of half the wavelength, or 400 nm, which shall allow us to determine non-ambiguously the individual potential well in which the atom is trapped without the need of performing long-time averaging. - In developing this project, we must surmount challenging difficulties. However, these difficulties often imply an interesting underlying physics that deserves by itself to be studied. For example, placing an atom at a sub-micron distance of a microstructured material will modify the atom's properties, as its spontaneous emission rate. This is a very interesting experiment that is just starting to attract the attention of the community. In the same vein, the light issued from a microstructured fiber at sub-lambda distances of an atom can be used to manipulate the atom with unprecedented precision and finesse.

Scientific background and objectives Quantification of intracellular physiological and cytotoxic nucleoside/nucleotide pools by on-line SSPE LC-MS/MS methods The major obstacles of cancer chemotherapy are the severe side effects and the development of drug resistance. Due to the modest tumor specificity of many anticancer drugs, normal tissues are also damaged. This prevents the application of high sufficient doses to eradicate less sensitive tumor cell populations. Thereby, tumors develop drug resistance that leads to treatment failure and fatal consequences for patients. In addition, it is a well-known clinical observation that the same doses of medication cause considerable heterogeneity in efficacy and toxicity across human populations. This heterogeneity can lead to unpredictable life-threatening or even lethal adverse effects in small groups of patients. In this context, the current project focuses on cytotoxic nucleoside analogues which are commonly used in the treatment of solid tumors and hematological malignancies. Based on preliminary results, we propose to develop new analytical methods leading (i) to examine changes in endogenous nucleoside/nucleotide pools in cancer cells and how imbalances may lead to genetic mutations and a more aggressive cancer phenotype; (ii) to apply the method to the pharmacology of a nucleoside model (araC) in order to quantify its intracellular concentration as well as those of its phosphorylated metabolites. Initially developed using biological models (cell extracts, cell lines), the method will be applied to clinical samples. In this case, data will be correlated to the expression level (determined by rt-PCR) of selected cellular enzymes and results will be analyzed with mathematical, statistical and informatic tools in order to study the relationships between the different nucleoside and nucleotide pools, the influence of the different protein expression levels on these pools, and correlations between the pools and protein expression levels with sensitivity to cytotoxic compounds. The global objectives of this project are (i) to study the cellular impact induced by deregulation of physiological nucleoside/nucleotide pools, (ii) to identify best-tolerated and most effective treatment regimen using cytotoxic nucleosides and, (iii) to predict the emergence of resistance to this therapeutic class. Methodology The quantification of nucleosides, as well as their nucleotides, constitutes a challenge since the method requires both highest sensitivity and selectivity in order to detect, in a complex biological matrix, smallest amounts of analytes present among the myriad of other ribonucleotides and deoxyribonucleotides. Current approaches consist in the extraction and concentration of target analytes using solid phase extraction (SPE) sorbent followed by their analysis by liquid-chromatography (LC). However, as retention on classical SPE sorbents applied to samples is mainly based on non selective hydrophobic interactions, many other matrix components are co-extracted thus rendering difficult the detection and the quantification of target analytes in LC. Mass spectrometry (MS) seems to appear as a technique of choice to circumvent such a problem of identification of target analytes from complex matrices. However, it has been now largely reported that direct coupling of LC and MS suffers from suppression ionisation effect due to matrix components that may induce a high variability in the ionisation process of the target analytes, thus decreasing the method reliability in term of quantification. In this project, we propose to develop a selective solid-phase extraction (SSPE) procedure based on a sorbent developing a molecular recognition retention mechanism to isolate the target analytes from the complex matrices increasing by the way specificity and sensitivity of the method. This sorbent could be an immunosorbent produced using immobilised antibodies specific of the target analytes or a m

The goal of our research group is to address problems related to non-equilibrium systems by means of hydrodynamic limit theory. The main focus will be on deriving limit theorems and studying the scaling behaviors when the number of particles diverges. The questions which can be tackled depend on the complexity of the microscopic models considered: we plan to analyze the thermal conductivity (Fourier's law) for Hamiltonian systems, the non-equilibrium stationary states as well as fluctuation theorems for stochastic dynamics and finally the impact of disorder and kinetic constraints on transport properties. ...