Nouveaux concepts pour l’imagerie et la détection (NCIS)

Coordinateurs

Julien DE ROSNY

Tél. : 01 80 96 30 52

Claire PRADA

Tél. : 01 80 96 30 53

Actualités

Optical coherent detection through multi-scattering media by wave-mixing cleaning effect in liquid-crystal OASLM Bortolozzo, U., S. Residori, F. Ramaz, and J. P. Huignard Optics Letters 48, no. 15, 3969-3972 (2023) Résumé: Liquid-crystal (LC) optically addressable spatial light modulators (OASLMs) allow control of the phase and amplitude of optical beams. By performing wave mixing in an OASLM, we show that coherent phase detection can be achieved for light beams passing through highly scattering media, such as foam layers with several cm thicknesses. Thanks to the adaptive response of our OASLM, the phase information on the speckle signal is transferred at the output of the OASLM to the plane wave reference beam, allowing the cleaning of optical distortions and the direct measurement of amplitude phase modulations with a small diameter single photodiode. A good signal-to-noise ratio (SNR) is demonstrated for foam thickness up to 3 cm. These properties, together with the recently demonstrated sub-ms response time of our OASLM, make the method compatible with foreseen applications for imaging in biomedical tissues and turbid media.
Dynamic full-field optical coherence tomography for live-cell imaging and growth-phase monitoring in Aspergillus fumigatus Maldiney, T., D. Garcia-Hermoso, E. Sitterlé, J.-M. Chassot, O. Thouvenin, C. Boccara, M. Blot, L. Piroth, J.-P. Quenot, P.-E. Charles, V. Aimanianda, B. Podac, L. Boulnois, F. Dalle, M. Sautour, M.-E. Bougnoux, and F. Lanternier Frontiers in Cellular and Infection Microbiology 13 (2023) Résumé: The diagnosis of cutaneous manifestations of deep mycoses relies on both histopathological and direct examinations. Yet, the current diagnostic criteria cannot prevent missed cases, including invasive aspergillosis, which requires the development of a novel diagnostic approach and imaging tools. We recently introduced the use of dynamic full-field optical coherence tomography (D-FF-OCT) in fungal diagnostics with a definition approaching that of conventional microscopy and the ability to return metabolic information regarding different fungal species. The present work focuses on subcellular dynamics and live-cell imaging of Aspergillus fumigatus with D-FF-OCT to follow the fungal growth stages Mots-clés: Aspergillus fumigatus; dynamic full-field optical coherence tomography; fungal metabolism; invasive fungal infections; live-cell imaging
Abnormalities in the retinal capillary plexuses in coasts disease in adulthood on optical coherence tomography angiography Krivosic, V., P. Mecê, C. Dulière, C. Lavia, S. Zegrari, R. Tadayoni, and A. Gaudric Retina (Philadelphia, Pa.) 43, no. 9, 1514-1524 (2023) Résumé: PURPOSE: To describe and quantify the abnormalities of the retinal capillary plexuses using optical coherence tomography angiography in Coats disease. METHODS: Retrospective study. Eleven eyes of 11 patients with Coats disease (9 men and two women aged 32-80 years) compared with nine fellow eyes and 11 healthy control eyes. Horizontal bands of contiguous 3 × 3 mm optical coherence tomography angiograms of the superficial vascular plexus and deep capillary complex were acquired from the optic disk to 6 mm temporal to the fovea, through areas with telangiectasia visible on fluorescein angiography in 9 cases. RESULTS: The vascular density was significantly decreased in both plexuses in eyes with Coats disease compared with normal and fellow eyes within the 6 mm temporal to the fovea (superficial vascular plexus: 21.5 vs. 29.4%, P = 0.00004 and vs. 30.3%, P = 0.00008; deep capillary complex, 16.5 vs. 23.9%, P = 0.00004 and vs. 24.7%, P = 0.00008, respectively). The fractal dimension was also significantly decreased in eyes with Coats disease (superficial vascular plexus: 1.796 vs. 1.848 P = 0.001 and vs. 1.833, P = 0.003; deep capillary complex: 1.762 vs. 1.853, P = 0.003 and vs. 1.838, P = 0.004, respectively). CONCLUSION: Retinal plexuses' vascular density was decreased in Coats disease, including in areas with no visible telangiectasia.
Real-time detection of virus antibody interaction by label-free common-path interferometry Alhaddad, S., H. Bey, O. Thouvenin, P. Boulanger, C. Boccara, M. Boccara, and I. Izeddin Biophysical Reports 3, no. 3, 100119 (2023) Résumé: Viruses have a profound influence on all forms of life, motivating the development of rapid and minimally invasive methods for virus detection. In this study, we present a novel methodology that enables quantitative measurement of the interaction between individual biotic nanoparticles and antibodies in solution. Our approach employs a label-free, full-field common-path interferometric technique to detect and track biotic nanoparticles and their interactions with antibodies. It is based on the interferometric detection of light scattered by viruses in aqueous samples for the detection of individual viruses. We employ single-particle tracking analysis to characterize the size and properties of the detected nanoparticles, and to monitor the changes in their diffusive mobility resulting from interactions. To validate the sensitivity of our detection approach, we distinguish between particles having identical diffusion coefficients but different scattering signals, using DNA-loaded and DNA-devoid capsids of the Escherichia coli T5 virus phage. In addition, we have been able to monitor, in real time, the interaction between the bacteriophage T5 and purified antibodies targeting its major capsid protein pb8, as well as between the phage SPP1 and nonpurified anti-SPP1 antibodies present in rabbit serum. Interestingly, these virus-antibody interactions are observed within minutes. Finally, by estimating the number of viral particles interacting with antibodies at different concentrations, we successfully quantify the dissociation constant Kd of the virus-antibody reaction using single-particle tracking analysis.

> Toutes les publications...

Présentation du thème

Les recherches menées au sein de ce thème sont tournées vers les applications, elles reposent sur une alliance de compétences variées en physique des ondes, traitement de signal et instrumentation et se nourrissent principalement des travaux menés dans le thème ondes en milieux complexes. L’idée est d’exploiter la diversité temporelle et/ou spatiale des ondes pour développer de nouvelles méthodes de détection et d’imagerie dans des contextes applicatifs variés allant de l’imagerie biologique au contrôle non destructif. Ces méthodes sont implémentées pour différents types d’ondes, acoustiques, élastiques et optique et sont souvent multi-ondes (ultrasons laser, acousto-optique, élasto-acoustique). Elles reposent sur des principes physiques tels que la réciprocité, l’invariance par retournement temporel, l’émergence des fonctions de Green par corrélation de bruit et exploitent les technologies de réseaux multiéléments : réseaux de microphones ou de transducteurs piézo-électriques, réseaux d’antennes, capteurs CCD, modulateurs spatiaux de lumière.

Le thème est structuré en quatre axes : l’imagerie optique plein champ, l’acousto-optique en milieu diffusant, les méthodes multi-éléments en acoustique et les ondes élastiques guidées appliquées à l’évaluation des matériaux.

Membres

Axes de recherche

Activités passées

Haut de page

L’Institut Langevin

Actualités

Recherche

Membres

Publications

Séminaires & écoles thématiques

Enseignement

Nous recrutons

Contact

Nouveaux concepts pour l’imagerie et la détection (NCIS)

Coordinateurs

Actualités

Présentation du thème

Membres

Axes de recherche