Capteur en Optique Intégrée à Base de Verres de Chalcogénures pour la Détection de Polluants dans le Moyen-Infrarouge

National audienceLe Moyen Infra-Rouge (MIR) est la région spectrale comprise entre 3 et 20 µm. Cette gamme de longueurs d’onde est connue pour contenir des transitions vibrationnelles fondamentales caractéristiques d’espèces moléculaires en phase liquide ou gazeuse. De nombreuses substances telles que le toluène, le méthanol, l’éthanol, l’acétone, le glucose, le dioxyde de carbone peuvent être caractérisées par spectroscopie infrarouge grâce à leur signature spectrale d’absorption. Cette technique est ainsi une des plus appropriées parmi les techniques classiques d’analyse pour l’identification et la caractérisation structurelle des espèces moléculaires. Les disponibilités récentes de plateformes optiques présentant de faibles pertes de propagation et de sources émettant dans le MIR, notamment des QCL ont été la clé du développement d’études destinées à la réalisation de capteurs optiques fonctionnant dans la gamme spectrale du MIR. Par ailleurs, les capteurs en optique intégrée sont devenus une excellente alternative pour la détection in situ car ils présentent certains avantages sur les autres types de capteurs, tels que l'intégration des éléments dans un dispositif compact. Ils sont actuellement utilisés dans divers domaines sociétaux tels que la santé, la défense et l’environnement.Il existe différents matériaux transparents dans le MIR (le silicium, le germanium, l’arséniure de galium ou encore les verres de chalcogénures) susceptibles de constituer la plateforme optique de ces capteurs intégrés. Les verres de chalcogénures (ChGs) sont des matériaux semi-conducteurs composés par les éléments du groupe VIa (sélénium (Se), tellure (Te) ou soufre (S)). Ils forment des verres lorsqu’ils sont mélangés à un ou plusieurs autres éléments tels que le galium (Ga), le germanium (Ge), l’antimoine (Sb), le silicium (Si) ou le phosphore (P). Ces verres de ChGs se distinguent par leur transparence étendue dans l’infrarouge: certaines compositions transmettent jusqu’à 20 µm. Typiquement, leur transmission dans le MIR a été caractérisée jusqu’à 12 µm pour les sulfures, à 16 µm pour les séléniures et à 18 µm pour les tellures. Certains travaux ont montré la fabrication et la caractérisation de capteurs optiques dans le proche infra-rouge. Dans cet article, nous proposons de tirer profit de la transparence élevée de ces matériaux dans le MIR pour fabriquer un capteur spectroscopique à onde évanescente fonctionnant dans cette gamme spectrale.

Bifeo3 Harmonic Nanoparticle (Bfo-Hnps) Use for the Stem Cell Tracking: Labeling Investigation by Non Linear Microscopy and X-Ray Fluorescence

Duchenne Muscular Dystrophy is the most common form of degenerative muscle disease; currently, there is no effective treatment. In 2011, our group showed that an adult stem cell population (MuStem) isolated from healthy dog skeletal muscle induces long-term muscle repair and striking clinical efficacy after its systemic delivery in clinically relevant dystrophic dog. During last years, our group isolated the human counterparts (hMuStem) [1]. To achieve the full therapeutic potential of the hMuStem cells, their homing process, survival and engraftment post-transplantation must be clearly understood. BiFeO3 harmonic nanoparticles (BFO-HNPs) were used as probes for the hMuStem cell tracking [2]. We demonstrate the possibility of identifying <100 nm BFO-HNPs in depth of muscle tissue at more than 1 mm from the surface by multiphoton microscopy. Based on this successful assessment, we monitor over 14 days any modification on proliferation and morphology features of the hMuStem cells upon exposure to BFO-HNPs revealing their high biocompatibility. To complete these studies, the stability of BFO-HNPs was followed in the labeled hMuStem cells by investigation of Bi and Fe X-ray fluorescence mapping on both Nanoscopium (Soleil, Gif-sur-Yvette, France) and ID16B (ESRF, Grenoble, France) beamlines. In this work, correlation between non-linear microscopy and X-Ray fluorescence was done. Bi and Fe X-Ray fluorescence allowed us to localize with high resolution the BFO-HNPs in the labeled hMuStem cells and the variation of Bi/Fe ratio was analyzed to detect possible dissociation of the nanoparticles in the labeled cells

Technologie d'optique intégrée au laboratoire Foton

National audienceCet article résume le panorama de l'état de l'art des technologies d'optique intégrée maitrisées au laboratoire Foton (Systèmes Photoniques) axé sur l'optique intégrée polymère active et passive, les guides en silicium et silice poreuse pour la réalisation de capteurs biologiques, ainsi que les applications des guides en verres spéciaux étudiés en collaboration avec d'autres laboratoires

Technologie d'optique intégrée polymère au laboratoire FOTON

National audienceCet article résume le panorama de l'état de l'art des technologies d'optique intégrée polymère maitrisées au laboratoire Foton (Systèmes Photoniques) et qui sont axées sur des circuits optiques actifs et passifs. Les objectifs sont orientés vers un fort confinement du mode de propagation, la génération d'effets non linéaires, l'hybridation avec d'autres matériaux et la réduction des pertes (couplage et propagation)

Bone Morphogenetic Protein 2 and Transforming Growth Factor β1 Inhibit the Expression of the Proinflammatory Cytokine IL-34 in Rheumatoid Arthritis Synovial Fibroblasts

IL-34 is a proinflammatory cytokine implicated in rheumatoid arthritis (RA). The current study aimed to assess the IL-34 expression in response to two members of the transforming growth factor (TGF)-β family, TGF-β1 and bone morphogenetic protein (BMP)-2, in synovial fibroblasts from RA patients. IL-34, TGF-β1, and BMP-2 productions were measured in patient synovial fluids by enzyme-linked immunosorbent assay. IL-34 mRNA levels were quantified by real-time quantitative PCR in human synovial fibroblasts and murine mesenchymal stem cells. Pharmacologic inhibitions were used to determine the involvement of activin receptor-like kinase 1 (ALK1) and ALK5 downstream TGF-β1 and BMP-2. IL-34, TGF-β1, and BMP-2 were expressed in synovial fluids from RA patients. We found a significant correlation between IL-34 and TGF-β1 expressions. Levels of both IL-34 and TGF-β1 were thus correlated with the total leukocyte counts in the synovial fluids. TGF-β1 and BMP-2 decreased IL-34 expression in the synovial fibroblasts or in murine mesenchymal stem cells in a dose- and time-dependent manner through ALK5 and ALK1 pathways, respectively. In addition, TGF-β1 and BMP-2 antagonized tumor necrosis factor α–induced IL-34 gene expression. This work identifies TGF-β1 and BMP-2 as potent inhibitors of IL-34 expression in RA synovial fibroblasts. These cytokines, as upstream inhibitors of IL-34, may thus contribute to antagonize inflammation and bone erosions in RA

The Behavioural Response of Australian Fur Seals to Motor Boat Noise

Australian fur seals breed on thirteen islands located in the Bass Strait, Australia. Land access to these islands is restricted, minimising human presence but boat access is still permissible with limitations on approach distances. Thirty-two controlled noise exposure experiments were conducted on breeding Australian fur seals to determine their behavioural response to controlled in-air motor boat noise on Kanowna Island (39°10′S, 146°18′E). Our results show there were significant differences in the seals' behaviour at low (64–70 dB) versus high (75–85 dB) sound levels, with seals orientating themselves towards or physically moving away from the louder boat noise at three different sound levels. Furthermore, seals responded more aggressively with one another and were more alert when they heard louder boat noise. Australian fur seals demonstrated plasticity in their vocal responses to boat noise with calls being significantly different between the various sound intensities and barks tending to get faster as the boat noise got louder. These results suggest that Australian fur seals on Kanowna Island show behavioural disturbance to high level boat noise. Consequently, it is recommended that an appropriate level of received boat sound emissions at breeding fur seal colonies be below 74 dB and that these findings be taken into account when evaluating appropriate approach distances and speed limits for boats

Influence of Social and Behavioural Characteristics of Users on Their Evaluation of Subjective Loudness and Acoustic Comfort in Shopping Malls

A large-scale subjective survey was conducted in six shopping malls in Harbin City, China, to determine the influence of social and behavioural characteristics of users on their evaluation of subjective loudness and acoustic comfort. The analysis of social characteristics shows that evaluation of subjective loudness is influenced by income and occupation, with correlation coefficients or contingency coefficients of 0.10 to 0.40 (p<0.05 or p<0.01). Meanwhile, evaluation of acoustic comfort evaluation is influenced by income, education level, and occupation, with correlation coefficients or contingency coefficients of 0.10 to 0.60 (p<0.05 or p<0.01). The effect of gender and age on evaluation of subjective loudness and acoustic comfort is statistically insignificant. The effects of occupation are mainly caused by the differences in income and education level, in which the effects of income are greater than that of education level. In terms of behavioural characteristics, evaluation of subjective loudness is influenced by the reason for visit, frequency of visit, and length of stay, with correlation coefficients or contingency coefficients of 0.10 to 0.40 (p<0.05 or p<0.01). Evaluation of acoustic comfort is influenced by the reason for visit to the site, the frequency of visit, length of stay, and also season of visit, with correlation coefficients of 0.10 to 0.30 (p<0.05 or p<0.01). In particular, users who are waiting for someone show lower evaluation of acoustic comfort, whereas users who go to shopping malls more than once a month show higher evaluation of acoustic comfort. On the contrary, the influence of the period of visit and the accompanying persons are found insignificant