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We have reproduced a percolating structure in thin Ni films by an inhomogeneous sputtering process. The morphological disorder has been studied using TEM and ` in situ' transport measurements during ion irradiation. The fluence dependence of the resistance shows a singularity following a 2D percolation law. The formation of the hole structure is consistent with a Poisson mechanism. A computer simulation developed using a code based on a Poisson statistics allows us to account for the experimental values of the percolation threshold and the overall shape of the infinite cluster.

We have investigated the scaling effects on the electron interface in inhomogeneous Ni films near the percolation threshold. As a result of the high exchange interaction of the conduction electrons, the conductance-anomaly at low temperature is due to the enhancement of the Coulomb e-e interactions by disorder. However, the magnetoresistance analysis shows that a small contribution of weak electron localization remains, while the enhancement of the e-e interactions is insensitive to the applied magnetic field. The signature of the modified dimensionality introduced by the percolating structure appears at very low temperature (T < 4 K) when the phase coherence scale is of the same order as the percolation length. In this regime, the study of the magnetoresistance renormalization proves that localization and magnetism coexist in itinerant ferromagnetic materials.

A nonequilibrium Mg hydride was prepared by low temperature hydrogen implantation in Mg thin films. In contrast to the usual compound in which H is charged under high pressure and elevated temperature, no structural phase transformation from hexagonal to tetragonal is observed here. Implanted H atoms progressively fill the tetrahedral interstitial sites of the Mg hexagonal cell up to a concentration H/Mg around one. The resulting hydride is metallic whereas the classical MgH2 is an insulator.

Desmin-related myopathy is a familial or sporadic disease characterized by skeletal muscle weakness and cardiomyopathy as well as the presence of intracytoplasmic aggregates of desmin-reactive material in the muscle cells. Previously, two kinds of deletions and eight missense mutations have been identified in the desmin gene and proven to be responsible for the disorder. The present study was conducted to determine structural and functional defects in a pathogenic desmin variant that caused a disabling disorder in an isolated case presenting with distal and proximal limb muscle weakness and cardiomyopathy. We identified a novel heterozygous Q389P desmin mutation located at the C-terminal part of the rod domain as the causative mutation in this case. Transfection of desmin cDNA containing the patient's mutation into C2.7, MCF7, and SW13 cells demonstrated that the Q389P mutant is incapable of constructing a functional intermediate filament network and has a dominant negative effect on filament formation. We conclude that Q389P mutation is the molecular event leading to the development of desmin-related myopathy.

We have studied the magnetic properties of thin inhomogeneous Ni films in the vicinity of a percolating threshold. A detailed analysis of the extraordinary Hall effect as a function of temperature gives quantitative information on the variation of the magnetic order. We show that the Hall effect is related to the magnetic properties at the grain scale. The strength of the magnetic coupling is insensitive to the film morphology. The magnetic behavior is similar to that of homogeneous thin films.

Metastable MgHx hydride was prepared by H ion implantation into Mg films at 5 K. The resistivity and magnetoresistance temperature dependence reveal weak localization effects due to atomic disorder. At low hydrogen concentrations, x ≤0.3, the conductivity varies as σ∼log (T), typical of two-dimensional weak localization behaviour. The resistivity is also very sensitive to the sample inhomogeneity, due to H diffusion, which can be modelled by introducing a temperature-dependent geometrical percolating factor G. At higher H concentrations, 0.7 ≤x ≤3, after annealing at 20 K, 50 K and 110 K, the samples also exhibit weak localization but with three-dimensional behaviour i.e. a $\sigma \sim \sqrt{T}$. Our analysis is consistent with the existence of an inhomogeneous system formed by a mixture of two phases with contrasted conduction properties, one of which is a well-behaved metal, while the other displays the localization properties. The results lead us to identify the former phase to a non percolating superconducting phase at low temperature.

Thin metallic Pd films (100 Å) were submitted to irradiation with 100 KeV Xe ions. After an initial increase of the atomic disorder, a decrease of the metallic coverage occurs as holes are created due to sputtering. This leads to a percolating transition. The modifications of the electronic mean free path, film thickness and metallic surface coverage were measured in situ up to the percolation threshold by means of resistive measurements, Rutherford Backscattering and Transmission Electron Microscopy experiments. The resistance at 300 K is found to diverge near the percolation threshold with the typical 2D exponent value. A phenomenological model accounts for the evolution of the topological parameters as the fluence (number of incoming ions per unit surface) increases. We present low temperature electrical measurements on films irradiated at different fluences, thus lying at different distances from the percolation threshold. Our results show a strong interaction between the microscopic and the macroscopic disorder near the percolation threshold : the conductance temperature dependence crosses over from a logarithmic shape (i.e. characteristic of weak localization in 2D metallic films) to a power lam dependence, due to the non-Euclidean (fractal) dimensionality of the percolating metallic structure. Moreover, very close to the threshold but always above it, the conductance varies exponentially with temperature, revealing the appearance of an Anderson insulator, although a continuous metallic path exists across the samples. At 4.2 K, the resistance approaches the percolation threshold with exponent 2, (different from the classical percolation value 1.3 observed at 300 K). This new exponent must contain information on the observed Metal-Insulator Transition.

Rutherford backscattering experiments are performed on ultrathin percolating Pd films during irradiation at 300 K with Xe ions. The spectra are sensitive to the topology of the films, allowing us to follow the appearance of a percolating structure.

Objectif Decrire la place de la douleur comme principal motif d’appel au 15 pour les affaires concernant la Regulation de la Permanence des Soins. Identifier les principaux contextes douloureux exposes par les appelants. Methode Etude retrospective portant sur le codage de toutes les affaires traitees durant l’annee 2006 par la regulation de la permanence des soins d’un Centre 15 dans un departement de 1 450 000 habitants. La douleur etait consideree comme un motif d’appel lorsque le code faisait reference a une pathologie douloureuse ou lorsque le mot « douleur » ou « algie » figurait dans son intitule. Les appels codes par la regulation SAMU (urgences vitales) ont ete exclus. Resultats La douleur etait avancee parmi les principaux motifs d’appel dans 30 % des 82 862 affaires medicales traitees durant l’annee. 65 % des affaires concernaient des pathologies non ou peu douloureuses ou d’autres motifs d’appel. 5 % des appels etaient sans objet. Les principales causes d’appels motives par un contexte douloureux etaient d’origine : abdominale (21 %), ORL (18 %), traumatologique (16 %), rhumatologique (11 %), diffuse (10 %), urologique (7 %), cephalique (6 %), oculaire (4 %), dentaire (3 %), thoracique (2 %), cancereuse (1 %) et enfin gynecologique (1 %). 56 % des douleurs ORL etaient des otalgies, 62 % des douleurs rhumatologiques etaient des lombosciatiques et 75 % des douleurs urologiques etaient des infections urinaires. L’analyse des donnees n’a pas permis de donner la part respective des douleurs aigues et des douleurs chroniques. Discussion La regulation de la permanence des soins (de ce departement) recoit en moyenne 68 appels par jours motives par une douleur. Les appels les plus longs a gerer (polyalgies, cephalees, douleurs dentaires, douleurs cancereuses) sont (heureusement) minoritaires. Cette analyse nous incite a affiner le codage des symptomes douloureux pour faire apparaitre leur caractere aigu ou chronique.

Objectif Le but de ce travail etait de recenser les medicaments antalgiques disponibles dans les vehicules SMUR primaires adultes et de decrire l’evolution constatee entre 1992 et 2007. Methode Cette enquete longitudinale a ete realisee a l’aide d’une check-list de 25 produits antalgiques confrontee aux medicaments disponibles dans les vehicules des SMUR primaires adultes d’une region. Le sondage a ete realise dans les memes conditions en 1992, 1997, 2002 et 2007. Lorsque les resultats etaient stables, un seul chiffre est donne. Lorsqu’ils evoluaient les chiffres de 1992, 1997, 2002 et 2007 sont donnes en serie. Resultats Les donnees presentees concernent 38 services, 83 equipes medicales, 120 vehicules SMUR (taux de reponse 100 %). Le pourcentage d’equipes disposant de chaque produit etait : Acupan (Nefopam) 5 %-5 %-11 %-19 %, Emla 0 %-2 %-24 %-39 %, Fentanyl = 64 %-77 %-95 %-70 %, Gamma-OH (Hydroxybutyrate de sodium) 45 %, Ketalar (Ketamine) 77 %-73 %-73 %-98 %, Marcaine (Bupivacaine) 14 %-18 %-14 %-1 %, Morphine = 43 %-59 %-92 %-100 %, Naropeine (Ropivacaine) 0 %-0 %-5 %-22 %, Noramidopyrine 10 %, Nubain (Nalbuphine) = 26 %-52 %- 43 %-28 %, Paralyoc (Paracetamol perlingual) 5 %-7 %-24 %-8 %, Prodafalgan/Perfalgan (Proparacetamol) 100 %, Profenid (Ketoprofene) 11 %-27 %-53 %-71 %, Protoxyde d’azote 43 %-53 %-65 %-94 %, Rapifen (Alfentanil) 2 %-1 %-1 %-11 %, Spasfon IV (Phloroglucinol) 70 %, Spasfon lyoc 15 %, Sufenta (Sufentanil) 0 %-0 %-7 %-57 %, Temgesic (Buprenorphine) 1 %-5 %-13 %-12 %, Xylocaine (Lidocaine) 100 %. Le nombre de representants de chaque classe dans un vehicule etait (en moyenne) : morphiniques IV 1,5-1,9-2,5-2,7 ; antalgiques peripheriques 1,9-2,1-2,5-3,7 ; anesthesiques locaux injectables 1,2. Discussion L’evolution reguliere de la dotation des SMUR en antalgiques traduit une volonte de diversification en accord avec une prise en charge multimodale de la douleur en pre-hospitalier.

The conduction band distortion and LO phonon energy of GaAs, the transition temperature, the energy gap and the phonon energies in superconducting lead film, have been measured at pressures up to 30 kbar by electron tunnelling through Schottky barriers.

We report low-temperature irradiation experiments with helium ions (190 keV) on thin YBa2Cu3O7 films 500 nm thick deposited on MgO (100 orientation) substrates. The temperature dependence of the resistance was measured in situ. We analyze the relation between the irradiation-induced damage, the increase in the normal resistance and the decrease of the critical superconducting temperature. Our analysis includes the result of a recent transmission electron microscopy study demonstrating the existence of an irradiation-induced orthorhombic to tetragonal transition. The change of the shape of the transition curve under irradiation is interpreted in terms of the superconductivity of inhomogeneous media.

We report on electrical resistivity versus temperature from 50 K down to 1.5 K of PtAl2O3 and AuAl2O3 cermets. When the metal volume fraction q is below the percolation threshold qc, the dc conductivity shows a temperature dependence of the form ln σ ∝ T−n which is usually related to variable range hopping conduction. When T ∗ (T ∗ ≌4.6 K) , the exponent value is n = 1 4 and above T∗ the temperature dependence is modified with n = 1 2 . This behaviour is not clearly understood and is discussed in view of recent theoretical works. For q≌q c a metallic behaviour is observed at high temperature while at liquid helium temperature a two-dimensional electron-electron interaction effect is invoked to describe the anomalous non-metallic behaviour.

The metal-insulator transition has been induced by hydrogen implantation at low fluence in a macroscopically inhomogeneous percolating Al-Ge mixture near the percolation threshold. The transition is reversible by annealing, showing that hydrogen implantation increases the local disorder in the Al metal grains without affecting the percolation structure. We submit that this is the first experimental evidence of an Anderson (metal-insulator) transition in a three-dimensional pure metal.

This paper discusses critically the previous calculations of the Tomasch oscillations in the density of state of superconductors. We show that these periodic structures should depend strongly on the variation of the pair potential in the film as well as at the interface.