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Resume La determination de l’atteinte mediastinale chez les patients non metastatiques est un temps essentiel de la prise en charge initiale de tout cancer broncho-pulmonaire non a petites cellules permettant de decider du traitement le plus adapte a proposer au patient. Si la chirurgie constitue une reference puisqu’elle a une meilleure valeur predictive negative, l’echoendoscopie (oesophagienne ou bronchique) est recommandee en premiere intention pour le staging car elle est performante, qu’il existe moins de complications consecutives, que les couts engages sont moins importants et qu’elle peut par ailleurs etre realisee sans anesthesie. Les explorations plus invasives restent indiquees lorsque les prelevements realises lors de l’endoscopie sont negatifs ou lors de la reevaluation apres realisation d’un traitement d’induction qui est un cas a part. De la complementarite de ces deux examens est ne le CUS (combined utrasound) permettant un staging mediastinal medical quasi-complet. Cette technique plus sensible est cependant difficile a organiser en pratique raison pour laquelle d’authentiques explorations para-oesophagiennes sont maintenant realisees par les pneumologues a l’aide de leur echobronchoscope (EUS-B).

Made available in DSpace on 2018-12-11T16:40:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-01-01 Precise Point Positioning (PPP) is a well-known technique of positioning by Global Navigation Satellite Systems (GNSS) that provides accurate solutions. With the availability of real-time precise orbit and clock products provided by the International GNSS Service (IGS) and by individual analysis centers such as Centre National d’Etudes Spatiales through the IGS Real-Time Project, PPP in real time is achievable. With such orbit and clock products and using dual-frequency receivers, first-order ionospheric effects can be eliminated by the ionospheric-free combination. Concerning the tropospheric delays, the Zenith Hydrostatic Delays can be quite well modeled, although the Zenith Wet Delays (ZWDs) have to be estimated because they cannot be mitigated by, for instance, observable combinations. However, adding ZWD estimates in PPP processing increases the time to achieve accurate positions. In order to reduce this convergence time, we (1) model the behavior of troposphere over France using ZWD estimates at Orphéon GNSS reference network stations and (2) send the modeling parameters to the GNSS users to be introduced as a priori ZWDs, with an appropriate uncertainty. At the user level, float PPP-RTK is achieved; that is, GNSS data are performed in kinematic mode and ambiguities are kept float. The quality of the modeling is assessed by comparison with tropospheric products published by Institut National de l’Information Géographique et Forestière. Finally, the improvements in terms of required time to achieve 10-cm accuracy for the rover position (simulated float PPP-RTK) are quantified and discussed. Results for 68 % quantiles of absolute errors convergence show that gains for GPS-only positioning with ZWDs derived from the assessed tropospheric modeling are about: 1 % (East), 20 % (North), and 5 % (Up). Since ZWD estimation is correlated with satellite geometry, we also investigated the positioning when processing GPS + GLONASS data, which increases significantly the number of available satellites. The improvements achieved by adding tropospheric corrections in this case are about: 2 % (East), 5 % (North), and 13 % (Up). Finally, a reduction in the number of reference stations by using a sparser network configuration to perform the tropospheric modeling does not degrade the generated tropospheric corrections, and similar performances are achieved. GeF Cnam Geodata Diffusion PPGCC/Unesp PPGCC/Unesp

Lors de la resection endoscopique d’un polype difficile, apres avoir accede a la lesion, il faut se positionner de facon a avoir une utilisation optimale et donc plus sure des instruments. L’utilisation des techniques de base permet la coloscopie complete dans plus de 90 % des cas. Le plus important est de reduire les boucles pour faciliter la progression et la resection. On distingue differents types de boucles dont la reduction necessite une manœuvre specifique. Ces differentes boucles ont ete etudiees grâce a la radioscopie et aux appareils donnant une representation de l’endoscope dans l’espace. La mobilisation du patient peut faciliter la progression ou la visualisation de la muqueuse. La pression abdominale peut etre d’une aide precieuse pour atteindre le caecum. L’utilisation d’overtubes, d’endoscopes a rigidite variable ou d’endoscopes a double ballon permet de pallier les echecs de la coloscopie standard. Une fois atteint, au moment de resequer, il faut essayer de positionner le polype a six heures en appliquant une rotation a l’endoscope. Cette manœuvre est plus facile avec un endoscope deboucle. La retrovision peut faciliter l’exposition d’un polype en particulier en sus anal, derriere un gros pli ou derriere la valvule. Elle est plus facile avec un endoscope souple comme un gastroscope ou un enteroscope a double ballon. Les gros polypes seront enleves a la descente, ce qui permet de deboucler et d’eviter de resequer un polype a proximite d’un cancer. L’utilisation de ces techniques permet un acces plus facile aux lesions, un meilleur positionnement et donc une resection dans des conditions plus sures.

Porous silicon (PSi) structure is used as support material to detect protein infiltration and to induce fluorescence and second harmonic light enhancement from glucose oxidase (GOX). Functionalization and protein infiltration is monitored by specular reflectometry. Optical response enhancement of PSi microcavity structures compared to PSi single layers or Bragg mirrors is observed, when GOX is impregnated. Penetration of organic molecules along the PSi microcavity structure is demonstrated by energy dispersive X-ray profile. Enhanced fluorescence emission of GOX when adsorbed on PSi microcavity is evidenced by multi-photon microscopy (MPM). Second harmonic light generation is observed at some particular pores of PSi and subsequent resonance enhancement of the signal arising from the GOX adsorbed within the pores is detected. Our work evidences an improved device functionality of GOX-PSi microcavities due to strongly confined and localized light emission within these structures. This opens the way towards the application of PSi microcavity structures as amended biosensors based on their locally enhanced optical response. The second main achievement lies in the novelty of the used techniques. In contrast to the specular reflectometry used to monitor the macroscopic optical response of PSi structures, MPM presents a valuable alternative microscopic technique probing individual pores. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The membrane protein bacteriorhodopsin in its native membrane bound form (purple membrane) was adsorbed and incorporated into polyelectrolyte multilayered films, and adsorption was in situ monitored by optical waveguide light-mode spectroscopy. The formation of a single layer or a double layer of purple membranes was observed when adsorbed on negatively or positively charged surfaces, respectively. The purple membrane patches adsorbed on the polyelectrolyte multilayers were also evidenced by atomic force microscopy images. The driving forces of the adsorption process were evaluated by varying the ionic strength of the solution as well as the purple membrane concentration. At high purple membrane concentration, interpenetrating polyelectrolyte loops might provide new binding sites for the adsorption of a second layer of purple membranes, whereas at lower concentrations only a single layer is formed. Negative surfaces do not promote a second protein layer adsorption. Driving forces other than just electrostatic ones, such as hydrophobic forces, should play a role in the polyelectrolyte/purple membrane layering. The subtle interplay of all these factors determines the formation of the polyelectrolyte/purple membrane matrix with a presumably high degree of orientation for the incorporated purple membranes, with their cytoplasmic, or extracellular side toward the bulk on negatively or positively charged polyelectrolyte, respectively. The structural stability of bacteriorhodopsin during adsorption onto the surface and incorporation into the polyelectrolyte multilayers was investigated by Fourier transform infrared spectroscopy in attenuated total reflection mode. Adsorption and incorporation of purple membranes within polyelectrolyte multilayers does not disturb the conformational majority of membrane-embedded alpha-helix structures of the protein, but may slightly alter the structure of the extramembraneous segments or their interaction with the environment. This high stability is different from the lower stability of the predominantly beta-sheet structures of numerous globular proteins when adsorbed onto surfaces.

Stable porous silicon microcavities (PSiMcs) are designed in order to detect the confined glucose oxidase (GOX) at low concentration. A chemical pathway is proposed to functionalize and stabilize porous silicon structures that are primordial for further effective molecular confinement. The procedure avoids the preliminary thermal oxidation of the PSi surface and consists of a direct surface oxidation during the silanization process, an amino activation by a linker that also prevents further oxidation, and the binding of the GOX enzyme. Functionalization and protein confinement are monitored by the narrow resonance peaks in the near-infrared region (700–1000 nm) of the engineered meso- and macroporous microcavities. Protein penetration along the entire, large pore sized structure is demonstrated. The protein retains its native form within the properly functionalized PSi structures, which are ideal for molecular sensing also due to their high quality factor. A detection resolution of 25 nM GOX has been determined, thus demonstrating the high quality sensing of our functionalized porous silicon microcavity structures.

International audience; Photonics technology is employed in a growing number of applications. Biological and chemical sensors (E. Udd, Fiber Optic Sensors: An Introduction for Engineers and Scientists, Wiley, New York, 1991 [1]) for health and environment demand an adaptable technology. Network development towards the end-user requires more interconnecting components. Vision, lighting, data processing in hostile environment (spatial, military) need specific technologies. A flexible and low-cost process using good quality material is necessary. The sol-gel process is a chemical method to fabricate glasses at ambient pressure and moderate temperature. Hybrid materials (H.K. Schmidt et al., Proc. SPIE 3136, 220 (1997) [2]), mixing organic and inorganic parts, offer the advantages of polymer-like materials and glasses. We report on a new hybrid sol-gel technology to overcome the drawbacks of the formerly presented one (H. Krug, F. Teillantes, P.W. Oliviers, and H. Schmidt, Proc. SPIE 1758, 448 (1992) [3]). We present the material synthesis, an accurate and flexible fabrication process based on a pulsed UV laser lithography system and the characterisation of the optical waveguides and photonic circuits realised.

Angular-dependent reflection measurements were used to map out the dispersion relations of the resonant Bloch modes, and the angular dispersion of the phonon modes, in a photonic crystal consisting of selectively grown GaN pyramids containing a single InxGa1-xN/GaN quantum well. The dispersion of the photons exhibits strong photonic crystal characteristics, while the mean indium content of the 2 nm thickness InxGa1-xN layer was extracted from the angular dispersion of the phonon modes.

We have demonstrated the giant enhancement of second-harmonic generation in a one-dimensional GaN photonic crystal structure caused by the simultaneous achievement of strong fundamental field confinement and quasi-phase matching conditions. We have firstly measured the linear dispersive properties of the resonant modes for various azimuthal directions to predict the quasi-phase matching conditions. The theory based on a rigorous scattering matrix method has provided a good description of the equi-frequency surfaces. We have then shown that the equi-frequency surfaces may be used to identify the angular situations for which the quasi-phase matching conditions can be satisfied. The SHG enhancement achieved due to the double resonance was 5000 times greater than for the unpatterned GaN layer.

We report on results of the fabrication and the micro-reflectance measurement of GaN photonic crystals. The etching performance of GaN has been studied with a conventional reactive ion etching system and SiCl4 plasma. We obtained an etch rate of 100 nm/min and etching depth of 600 nm for dense GaN pillars. With graphite lattice of 270 run period we observed a high reflection peak in the region of 400 nm wavelengths, depending strongly on the incident light polarization, which is in a good agreement with the theoretical calculation. (C) 2001 Elsevier Science B.V. All rights reserved.

Pr 3+ -doped CaF 2 layers on CaF 2 (111) substrates were grown by molecular beam epitaxy. The effect of Pr concentration on spectroscopic properties and waveguide characteristics of the thin films was investigated and the existence of clustering of the tripositive praseodyme ions in CaF 2 was put forward to explain certain optical results. Photoluminescence spectra were obtained in the wavelength range 590–650 nm for 3 P 0 → 3 F 2 and 3 P 0 → 3 H 6 transitions of Pr 3+ ions, and a 3 P 0 level lifetime of the order of 100 μs was measured. This work demonstrates that active optical waveguides, useful for integrated optoelectronic devices, can be produced by growing Pr-doped CaF 2 epitaxial layers.

“Aging,” defined as the drift of resistance with temperature after 1000 h, was investigated for iron manganite temperature coefficient thermistors. For these devices, aging is relatively large, about 10%. The cationic distributions before and after aging were determined by Mössbauer spectroscopy. These distributions explain all the x-ray diffraction and correlated electrical data. The origin of the aging observed on iron manganites thermistors has been identified. It is due to the migration of Fe3+ ions from tetrahedral to octahedral sites of the spinel structure in order to reach a structural equilibrium.

Les thermistances a Coefficient de Temperature Negatif (CTN) elaborees a partir de manganites de metaux de transition a structure spinelle presentent, sous contrainte thermique, le phenomene de vieillissement. La derive de leur resistance depend de la composition chimique, de la structure cristallographique (cubique ou quadratique) et des traitements thermiques. Precedemment, nous avons montre, pour les thermistances a base de manganites de fer de composition Mn 3 - x Fe x O 4 (avec 0 ≤ x ≤ 1,51), que le vieillissement est du a une migration des ions Fe 3+ et Mn 2+ entre les sites tetraedriques et octaedriques de la structure spinelle. Une etude des manganites de fer a ete realisee par Microscopie Electronique a Transmission (MET) afin de relier la microstructure a la stabilite electrique. Pour les manganites de fer ayant une teneur en fer x ≤ 0,78, la microstructure en forme de domaines (micromaclages) resulte de la presence de deux types de defauts bidimensionnels. Pour des teneurs superieures, jusqu'a 0,78, cette microstructure disparait graduellement et se transforme en une microstructure tweed.

Yb:Er: codoped CaF2 monocrystalline films have been grown by molecular beam epitaxy (MBE) using YbF3, ErF3, and CaF2 evaporation on CaF2 substrates. Luminescence and excitation of luminescence at 25 K are measured in order to investigate the role of Yb3+ codoping and the effect of the growth conditions during the MBE process on the incorporation of active rare-earth species in CaF2. It is found, from a comparison with earlier work on singly doped thin films, that the energies of the levels of Er3+ ions are not modified by the double doping, whereas mixed complex centers are formed. Growth conditions are found to be important controlling factors for the incorporation of Yb3+ as a sensitizer, and, consequently, for the transfer efficiency. From excitation and absorption spectra it is shown that the lowest component of the Er:4I11/2 manifold has an energy higher than that of Yb:2F5/2 and the consequences are discussed.

Ascites, in 20% of cases, is not linked to liver cirrhosis. The pathophysiology is most often different. The understanding of these pathophysiological mechanisms can lead to etiologic diagnosis. The diagnostic approach is mainly based on the biological study of ascites, especially protein concentration and albumin gradient between serum and ascites. In Western countries, tumors and heart diseases are the predominant causes, while developing countries are mainly concerned by infectious diseases, among which tuberculosis is the leading cause. Other uncommon causes must be recognized, as ascites may be the presenting feature of the disease. Their knowledge will facilitate the therapeutic approach.

We present investigations on Degenerate Four Wave Mixing in bulk GaAs Fabry-Pérot microcavities at room temperature excited with femtosecond pulses. Due to increased interaction length and amplification of light fields in the cavity, the measured diffraction efficiency η≈2×10−3 at 878 nm is enhanced by a factor of roughly 30 compared to bulk GaAs without cavity. The results may be useful for exploiting the cavity enhancement effect for investigation of carrier kinetics at small excitation densities. For application purposes, the results renew the interest in ultrafast coherent deflectors for all-optical routing.

We study the subnanosecond reflectivity kinetics of distributed Fabry-Pérot cavities composed of two GaAs/AlAs Bragg reflectors enclosing a central GaAs layer. The structure reflectivity exhibits a sharp minimum in the absorption edge of GaAs at the temperature of 300 K, around the wavelength of 885 nm. The photogeneration of an electron-hole plasma causes a shift of the cavity resonance. The switch energy and the recovery time are investigated. Switching capabilities are observed with excitation energies of few tens of μJ/cm2. We correlate the reflectivity kinetics to the plasma dynamics in the central GaAs zone of the structure, especially to the density and temperature relaxation.

We study the time-resolved reflectivity spectra of distributed Fabry-Perot (DFP) cavities following a picosecond laser excitation. The structures, which are composed of two GaAs/AlAs Bragg reflectors enclosing a central GaAs layer, exhibit a sharp reflectivity minimum slightly below the GaAs band gap. Due to the photogeneration of carriers in the central zone, we observe a red shift of 5–6 nm of the reflectivity minimum on a subnanosecond time scale. This effect enables one to deduce the plasma density from the spectra analysis. This method still works at low plasma density, i.e., for nondegerated plasma, when the standard luminescence method fails. The reflectivity of a photoexcited DFP is calculated by combining the absorption and index theory in the presence of thermalized carriers with a many-layer description of the structures (Abeles formalism). We trace the relaxation kinetics of the plasma density in the central zone of the microcavity and conclude the stimulated emission in the microcavity.

A quantitative analysis by derivative thermogravimetry based on the difference of reactivity in oxygen of Mn 2+ ions of iron manganite spinels Mn 3 − x Fe x O 4 with 0 x 2+ ions show that the oxidation proceeds by way of a diffusion-controlled reaction for Mn 2+ ions located at B sites and by a nucleation-growth mechanism for Mn 2+ ions located at A sites. The difference in the kinetics behavior has been attributed to a structural change cation-deficient spinel into multi-phase oxides induced by oxidation temperature.

Up conversion emission of Er3+ ions is reported for the first time for the case of molecular beam homoepitaxial CaF2:Er3+ thin layers. In contrast with the case of the corresponding bulk material the layers have been doped up to a high level of active impurity without any degradation of the crystal quality. The up converted green emission has been studied under excitation in the region of diode laser emission, at around 800 nm. The green emission intensity has been investigated as a function of the excitation power as well as the Er concentration. In the latter case, a quadratic dependence is obtained revealing the participation of Er3+ pairs in the up conversion process. The mechanism and the centers responsible for this up conversion phenomenon are discussed and the results are compared with those relative to the corresponding bulk crystals.

Single-phase iron manganite spinels, Mn 3−x Fe x O 4 with O ≤ x ≤ 1.05, were prepared by thermal processing of iron-manganese coprecipitated formate precursors. Powder X-ray diffraction (XRD) analysis shows a cubictetragonal transition for x = 1.05. The Mossbauer spectroscopy indicates the presence of only trivalent iron ions in both sites of the spinel structure. The electrical measurements show that these iron manganites have the characteristics of negative temperature coefficient thermistors. Moreover, in these solid solutions, the resistivity ρ decreases with increasing of iron content x . Correlation of the results obtained by XRD, Mossbauer spectroscopy and electrical measurements permits one to infer the cationic distribution, given by Mn 1 − y 2+ Fe y 3+ (Fe z 3+ Mn 2 − x 3+ Mn y 2+ O 4 2− with x = y + z .

In this paper we report our results on the preparation and characterization of copper—cobalt manganites, Mn2.6 − xCo0.4CuxO4 (0 ≤ x ≤ 1), obtained from coprecipitated oxalate precursors. Powder and single phase ceramics have been characterized by means of X-ray diffraction (XRD) and electrical conductivity measurements. The results of both characterization techniques are indicative of the ionic distribution for the copper—cobalt manganites solid solution studied: Mn0.6 − x2+Co0.42+Cux+ [Mn2 − x3+ Mnx4+] O42−; with 0 ≤ x ≤ 0.6, Co0.42+ Cu0.6+ [Cuy2+Mn1.4 − 2y3+ Mn0.6 + y4+] O42−; with 0.6

We report experimental results for the dispersion of Bloch modes in two-dimensional photonic crystals consisting of pillars in a graphite arrangement deeply etched into an asymmetric gallium–arsenide-based waveguide film. The quality factor Q of a confined mode that cannot be excited using normally incident plane waves (because of its spatial symmetry mismatch) has been estimated over a significant part of the Brillouin zone.

Lead colic is a rare cause of abdominal pain. The diagnosis of lead poisoning is most often mentioned in at risk populations (children, psychotic patients).We report a 21-year-old man who presented with colicky abdominal pain. Abdominal plain radiograph showed multiple intracolonic metallic bodies. Markedly elevated lead and zinc protoporphyrin serum levels confirmed the diagnosis of lead poisoning. The patient reported that he commonly chewed fishing lead sinker and may sometimes swallow them during the preparation of fishing rod. Clinical outcome was favourable with chelation therapy.Lead poisoning following fishing sinker ingestion is very uncommon. Diagnosis may be discussed in the presence of foreign metallic bodies on plain abdominal radiograph and confirmed by high serum level of lead. A prompt treatment with chelation therapy and digestive emptying is usually effective.

CaF2:Er layers have been grown by molecular‐beam epitaxy on (100)‐oriented CaF2 substrates; the Er concentration ranges from 1% to 50% (mole fraction). The 1.54 μm emission observed under excitation around 800 nm was studied by photoluminescence. Up to 35% Er concentration the integrated emission increases monotonously, quenching appearing for higher doping levels. Photoluminescence results are discussed within the framework of previous studies of Er3+ emission in the near‐infrared range (830–860 nm) in order to gain insight into the Er centers involved in the 1.54 μm emission.

Molecular beam epitaxy of Er‐doped CaF2 layers on (100)oriented CaF2 substrates was performed using CaF2 and ErF3 evaporation cells. The effect of growth temperature and Er concentration on the distribution of the different emission centers observed in these epitaxial Er‐doped layers was investigated. Photoluminescence analyses were performed in the 830–860 nm wavelength range in which the 4S3/2→4I13/2 transitions of the Er3+ ions take place. The evolution of the relative emission intensity between single and aggregate Er3+ centers as a function of growth temperature shows that the emission from isolated Er3+ ions is favored in a growth temperature range of 500–520 °C. Emission lines from complex Er3+ centers are found to rise relative to those of isolated sites as Er concentration increases. Finally, no quenching of the integrated luminescence intensity occurs in the concentration range investigated, 0.05–6 mol % (0.1–16 wt%).

Negative temperature coefficient (NTC) thermistors are ceramics of industrial interest because of the very high dependence of their electrical resistance on temperature. Generally, these materials consist of transition metal (Cu, Co, Ni, etc.) spinel manganites. This work shows the simultaneous influence of the purity and the morphology of initial powders on the densification. Moreover, correlations between electrical properties, thermal stability and microstructure have been established. Results of a comparative study on ceramics prepared either by conventional or chemical methods are given. Increasing the performance yields thermistors which have great precision and stability.

Les thermistances CTN constituees de manganites de metaux de transition presentent generalement des phenomenes de vieillissement sous contrainte thermique. Les derives observees dependent de la composition, de la structure (cubique ou quadratique), des traitements thermiques subis par la ceramique. Afin de tenter d'expliquer les correlations entre l'influence des traitements thermiques et les phenomenes de vieillissement, nous avons procede a une etude en microscopie electronique. D'une facon generale, les ceramiques refroidies tres lentement presentent des grains exempts de dislocations ou de defauts-plans. Au contraire, les ceramiques trempees sont toujours polyphasees et presentent des densites importantes de dislocations et de defauts-plans. Ces defauts bidimensionnels se manifestent sous forme de lamelles soit d'epaisseur comprise entre 30 et 600 nm (micromacles ou exsolutions), soit d'epaisseur beaucoup plus faible (structure “ tweed ”). Les phenomenes de vieillissement semblant lies a des diffusions atomiques dans le reseau spinelle, ces defauts intragranulaires pourraient jouer le role de barrieres vis-a-vis de la mobilite des ions et expliqueraient la meilleure stabilite thermique des ceramiques trempees.

Site selection spectroscopy has been used to study the different crystalline field centres for Nd3+ ions appearing in monocrystalline Nd3+ doped CaF2 thin films. The selective excitation has been performed resonantly in the 4F 3 2 multiplet in the nearinfrared region 850–900 nm and the emission was monitored in the region of laser interest for this material ≈ 1.05 μm. Three different Nd3+ centres are detected and the corresponding excitation and emission spectra are individually resolved. The results are compared with those obtained by a different optical technique relative to the case of CaF2 : Nd bulk crystals prepared by conventional growth methods, to find a good agreement in the energy level positions of Nd3+ ions.

Phase evolution and localization during sintering of spherical Bi-Ti-doped zinc oxide powders were studied by X-ray diffraction and transmission electron microscopy. Several minor phases were identified on quenched ceramics; a phase, either amorphous or crystalline, stable at a wide range of compositions, originating from solidification of the melt phase during quenching, was detected. Sintering processes were discussed: depending on the Ti content, densification, liquid-phase occurrence and grain growth are quite different.

Ceramic nickel‐copper‐manganite based negative temperature coefficient thermistors are unstable under thermal constraint, which increases the resistivity of these devices. This unstability can be reduced by the addition of a small amount of barium. These ceramics have a spinel structure, and the conduction takes place by a hopping process involving [Mn3+]/[Mn4+] octahedral ions. This study by the use of thermopower measurements points out that the resistivity change under thermal constraint is principally due to the disproportionation of [Mn3+]/[Mn4+] ions in the octahedral sites. Furthermore, it seems that some nickel ions migrate from octahedral to tetrahedral sites.