211 research outputs found
Elaboration par MOVPE des materiaux semiconducteurs II-VI a grand gap ZnSe et ZnTe: application a la croissance des superreseaux ZnSe-ZnTe
No full textSIGLEAvailable from INIST (FR), Document Supply Service, under shelf-number : T 82559 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc
Morphological and nanomechanical characterization of dental pulp stem cells in neuron co-culture and neurogenic differentiation
No full textInternational audiencePeripheral nerve injuries are serious traumas resulting in loss of motor and sensory functions of nerves. The post-traumatic neuropathies are often chronic and mostly resistant to current treatments. Our objective is to develop new strategies to regenerate nerve after trauma by biomimetic approaches and go towards in vitro neurogenesis. For this we use neural crest derived human multipotent dental pulp stem cells (hDPSC) in co-culture with sensory neurons from mice dorsal root ganglia (DRG), and an in vitro neurogenic differentiation of hDPSC [3].In order to explore nanomechanical and morphological characteristics of human DPSC and mouse DRG neurons atomic force microscopy was employed. We have shown that the mechanical properties of the soma and sub cellular growth cone regions correlate well with the amount, organization and dynamics of the underlying cytoskeletal structure [1,2]. Here we present preliminary data about hDPSC in co-culture, with mDRG neurons and during an in vitro neurogenic differentiation gathered by nanomechanical mapping.[1] O. Benzina, V. Szabo, O. Lucas, M-b. Saab, T. Cloitre, F. Scamps, C. Gergely and M. Martin (2013) Changes induced by peripheral nerve injury in the morphology and nanomechanics of sensory neurons, J. Biomedical Optics 18(10)[2] M. Martin, O.Benzina, V. Szabó, A. G. Végh, O. Lucas, T. Cloitre, F. Scamps and C. Gergely (2013) Morphology and Nanomechanics of Sensory Neurons Growth Cones following Peripheral Nerve Injury, Plos One , 8 (2)[3] M. Király, B. Porcsalmy, A. Pataki, K. Kádár, M. Jelitai, B. Molnár, P. Hermann, I. Gera, WD. Grimm, B. Ganss, A. Zsembery, G. Varga, (2009) Simultaneous PKC and cAMP activation induces differentiation of human dental pulp stem cells into functionally active neurons, Neurochem. Int. 55 (323-332
Epitaxial growth of ZnSiN2 single-crystalline films on sapphire substrates
No full textInternational audienceA new family of wide band gap nitride semiconductors expressed as II-IV-N-2 have recently attracted attention due to their expected properties such as optical non-linearity. In addition, among these compounds, ZnGeN2 and ZnSiN2 have lattice parameters close to GaN and SiC respectively. Up to now, there is very little work reported on this class of materials and no systematic thin film growth study has been reported to date. In this paper we present the first study on the growth of ZnSiN2 on c-sapphire and (100) silicon substrates using low pressure MOVPE technique. Triethylamine:dimethylzinc adduct, silane diluted in H-2 and ammonia were used as source materials. Single crystalline epitaxial ZnSiN2 layers were obtained on nitridated c-sapphire substrates in the temperature range 873-973 K by using an adapted II/IV molar ratio ranging from 1.2 to 12. Assuming an orthorhombic unit cell, the lattice parameters calculated from the X-ray diffraction data are a = 0.534 nm, b = 0.617 nm and c = 0.504 nm
Label-Free imaging by Broadband Coherent Anti-Stokes Raman Scattering (B-CARS) Microscopy
No full textInternational audienceBroadband CARS imaging is one of the Coherent Raman imaging (CRI) modalities with sub-cellular spatial resolution and providing an intrinsic fingerprint of chemical composition1. For biological samples, most of the characteristic Raman peaks are found in the ‘fingerprint’ spectral region, (~500 cm−1 to 1,800 cm−1 ), with the remaining found in the higher-energy CH-/OH-stretch region (~2,700 cm−1 to 3,300 cm−1). The various CRI techniques exhibit a large range in both performance and experimental setup complexity. For example, narrowband CARS microscopes are commercially available and could acquire image pixels very quickly but only probes narrow regions of the Raman spectrum. On the other hand, B-CARS acquire the full spectrum at the cost of longer pixel dwell time. In this talk, we will present the principles of the B-CARS microscopy we’ve developed in our laboratory and some examples of biological applications
Mechanisms of Psychological Distress following War in the Former Yugoslavia: The Role of Interpersonal Sensitivity
No full textThis is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.This study was funded by a grant from the European Commission, contract number INCO-CT-2004-509176. AN was supported by a Clinical Early Career Research Fellowship (113295) and a Project Grant (104288
Le cloitre des Dominicains de Collioure (PyrénéesOrientales): état de question
No full textL'any 1927, del claustre deis Dominicans de Colliure aixecat durant els primers decennis del segle XTV, només en quedava una galeria. Era la que corresponia al costat llarg de l'església. Comprat i desmuntat entre 1928 i 1931, el claustre en part es va dispersar cap a destinacions desconegudes i en part fou venut per adornar el pare del castell de Brindos a Anglet (Pirineus Atlàntics).
Els elements del claustre situats a Brindos, reconstruïts després del 1932, amb el pas dels anys, estan patint una degradació continuada i fins i tot, estan desapareixent. L'autora es proposa no només d'incidir en aquest problema, sinó que també intenta determinar quin era l'aspecte primitiu d'aquest claustre.En 1927 no quedaba más que una galería del claustro de los Dominicos de Colliure, levantado a lo largo de los primeros decenios del siglo XIV. Era la que correspondía al largo de la iglesia. Comprado y desmontado entre 1928 y 1931, el claustro fue parcialmente dispersado hacia destinos desconocidos y en parte, vendido para adornar el parque del castillo de Brindo en Anglet (Pirineos Atlánticos).
Estos elementos ubicados en Brindos, que fueron reconstruidos en 1932, no dejan de degradarse y sobre todo de desaparecer a lo largo de los años. La autora se propone. no sólo destacar este problema sino también intentar determinar cuál era el aspecto primitivo del claustro.In 1927, the only remains of the cloister of the Dominicans in Colliure, built in the first decades of the 14th century, consisted of a single gallery, corresponding to the length of the church. The cloister was sold and dismantled between 1928 and 1931 and it was partially dispersed in different unknown locations; a part of it was bought as ornament for the park at Brindo castle in Anglet (Pyrénees-Atlantiques).
These elements, scattered since 1932, are subject to continuous degradation and frequent looting. The author wishes to highlight this problem and clarify the original appearance of the cloister as well
Specific peptide for functionalization of GaN
No full textInternational audienceNanobiotechnology aims to exploit biomolecular recognition and self-assembly capabilities for integrating advanced materials into medicine and biology. However frequent problems are encountered at the interface of substrate-biological molecule, as the direct physical adsorption of biological molecules is dependent of unpredictable non-specific interactions with the surface, often causing their denaturation. Therefore, a proper functionalization of the substrate should avoid a loss of biological activity. In this work we address the functionalization of the semiconductor GaN (0001) for biosensing applications. The basic interest of using III-V class semiconductors is their good light emitting properties and a fair chemical stability that allows various applications of these materials. The technology chosen to elaborate GaN-specific peptides is the combinatorial phage-display method, a biological screening procedure based on affinity selection. An M13 bacteriophage library has been used to screen 1010 different peptides against the GaN (0001) surface to finally isolate one specific peptide. The preferential attachment of the biotinylated selected peptide onto the GaN (0001), in close proximity to a surface of different chemical and structural composition has been demonstrated by fluorescence microscopy. Further physicochemical studies have been initiated to evaluate the semiconductor-peptide interface and understand the details in the specific recognition of peptides for semiconductor substrates. Fourier Transform Infrared spectroscopy in Attenuated Total Reflection mode (FTIR-ATR) has been employed to prove the presence of peptides on the surface. Our Atomic Force Microscopy (AFM) studies on the morphology of the GaN surface after functionalization revealed a total surface coverage by a very thin, homogeneous peptide layer. Due to its good biocompatibility, functionalized GaN devices might evolve in a new class of implantable biosensors for medical applications
Towards the understanding of peptide/inorganic semiconductor complex interaction using molecular dynamics simulations
No full textInternational audienc
Towards the understanding of peptide/inorganic semiconductor complex interaction using molecular dynamics simulations
No full textInternational audienc
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