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Sainte-Foy-lès-Lyon, France
Sainte-Foy-lès-Lyon, France
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Planat-Chretien A.,CEA Grenoble | Berger M.,CEA Grenoble | Guichard N.,SILAB | Breugnot J.,SILAB | And 3 more authors.
Optics InfoBase Conference Papers | Year: 2016

In this paper, we show the relevance of the spatially resolved Diffuse Reflectance Spectroscopy (srDRS) measure to characterize skin optical properties in order to differentiate dull from bright tone of panelists within a cohort. We use a new Spectroscopic Tip Optical Probe (STOP) to quantify absorption and diffusion in seven zones of interest. We show the capacity of the STOP instrument to probe the medium, and identify characteristic physiological properties enabling to classify skin tones. © OSA 2016.


Gloaguen V.,University of Limoges | Brudieux V.,University of Limoges | Closs B.,SILAB | Barbat A.,University of Limoges | And 5 more authors.
Journal of Natural Products | Year: 2010

Zosterin, an apiose-rich pectic polysaccharide, was extracted and purified from the sea grass Zostera marina. Structural studies conducted by gas chromatography and NMR spectroscopy on a purified zosterin fraction (AGU) revealed a typical apiogalacturonan structure comprising an α-1,4-d- galactopyranosyluronan backbone substituted by 1,2-linked apiofuranose oligosaccharides and single apiose residues. The average molecular mass of AGU was estimated to be about 4100 Da with a low polydispersity. AGU inhibited proliferation of A431 human epidermoid carcinoma cells with an approximate IC50 value of 3 μg/mL (0.7 μM). In addition, AGU inhibited A431 cell migration and invasion. Preliminary experiments showed that inhibition of metalloproteases expression could play a role in these antimigration and anti-invasive properties. Autohydrolysis of AGU, which eliminated apiose and oligo-apiose substituents, led to a virtual disappearance of cytotoxic properties, thus suggesting a direct structure-function relationship with the apiose-rich hairy region of AGU. © 2010 The American Chemical Society and American Society of Pharmacognosy.


Jourlin M.,CNRS Hubert Curien Laboratory | Corvo J.,SILAB | Breugnot J.,SILAB
Pattern Recognition | Year: 2014

The present paper focuses on non-linear pattern matching based on the Logarithmic Image Processing (LIP) Model. Our contribution consists first of using the scalar multiplication defined in the LIP context to extend the little-known Asplünds metric to gray level images. Such a metric is explainable as a novel technique of double-sided image probing and presents the decisive advantage of being physically justified in the field of transmitted light acquisition. Moreover, thanks to the consistency of the LIP context with human vision, Asplünds metric is also applicable to images acquired in reflected light: in fact, plenty of image processing algorithms aim at extracting information as a human eye would do. Finally, the proposed approach is particularly efficient in the presence of lighting variations or lighting drift. In the paper, we also suggest a solution to overcome the main drawback of probing techniques, which resides in a high sensitivity to noise. Various examples are presented to highlight the efficiency of the method. © 2014 Elsevier Ltd.


Vyumvuhore R.,University Paris - Sud | Tfayli A.,University Paris - Sud | Piot O.,French National Center for Scientific Research | Le Guillou M.,SILAB | And 3 more authors.
Journal of Biomedical Optics | Year: 2014

Dermatologists need to combine different clinically relevant characteristics for a better understanding of skin health. These characteristics are usually measured by different techniques, and some of them are highly time consuming. Therefore, a predicting model based on Raman spectroscopy and partial least square (PLS) regression was developed as a rapid multiparametric method. The Raman spectra collected from the five uppermost micrometers of 11 healthy volunteers were fitted to different skin characteristics measured by independent appropriate methods (transepidermal water loss, hydration, pH, relative amount of ceramides, fatty acids, and cholesterol). For each parameter, the obtained PLS model presented correlation coefficients higher than R2 0.9. This model enables us to obtain all the aforementioned parameters directly from the unique Raman signature. In addition to that, in-depth Raman analyses down to 20 μm showed different balances between partially bound water and unbound water with depth. In parallel, the increase of depth was followed by an unfolding process of the proteins. The combinations of all these information led to a multiparametric investigation, which better characterizes the skin status. Raman signal can thus be used as a quick response code (QR code). This could help dermatologic diagnosis of physiological variations and presents a possible extension to pathological characterization. © 2014 Society of Photo-Optical Instrumentation Engineers.


Michel J.,Jean Monnet University | Maxime C.,Jean Monnet University | Josselin B.,Silab | Mohamed B.,NT2I
Advances in Imaging and Electron Physics | Year: 2012

The logarithmic image processing model is now recognized as a powerful framework to process images acquired in transmitted light and to take into account the human visual system. One of its major interests is linked to the strong mathematical properties it satisfies, allowing the definition and use of rigorous operators. In this paper, we introduce the concept of logarithmic additive contrast (LAC), its physical interpretation based on transmittance notion and some resulting properties: It represents by definition a grey level and it is highly efficient when computed on dark pairs of pixels, with applications for low-lighted images. Then the LAC is compared with the classical Michelson contrast, showing an explicit link between them. Furthermore, the LAC is demonstrated as very useful in the fields of automated thresholding and contour detection. Another major interest of the LAC is that it allows defining logarithmic metrics, opening various applications: grey-level images comparison, pattern recognition, target tracking, defect detection in industrial vision, and the creation of a new class of automated thresholding algorithms. Another part of the paper is dedicated to a novel notion of logarithmic multiplicative contrast (LMC), which appears as a positive real number and also presents a "physical" interpretation in terms of transmittance. Our research concerning the LMC remains today at an exploratory level if we consider the number of possible ways to deepen this notion. In fact, the LMC values may exceed the grey-scale maximum, which necessitates some normalization to display them as a contrast map. Nevertheless, the LMC is very sensitive near the bright extremity of the grey scale, which is very useful in processing overlighted images. As does the LAC, the LMC generates many new metrics, particularly the Asplünd one, and a metric combining information on shapes and grey levels. Until now, Asplünd's metric had been defined for binary shapes and is extended here to grey-level images, with interesting applications to pattern recognition. © 2012 Elsevier Inc. All rights reserved.


Jourlin M.,CNRS Hubert Curien Laboratory | Breugnot J.,CNRS Hubert Curien Laboratory | Itthirad F.,CNRS Hubert Curien Laboratory | Bouabdellah M.,NT2I | Closs B.,Silab
Advances in Imaging and Electron Physics | Year: 2011

The adaptation of grey-level logarithmic image processing to color is used to provide new kinds of tools for manipulating color images within the framework of a mathematically and physically justified model. These techniques are adapted for human perception in the use of color matching functions of the human eye in the elaboration of the model parameters. The results are found to depend on the precision of the color matching function used, and that diffusion and reflection phenomena are not yet taken into account. Some significant improvement has also been realized considering algorithm execution time, demonstrating that real-time treatments can be performed Results also show that that gain compensation is not enough and that saturation areas appear with the equalization. The algorithm provides details and the level of correction can be chosen.


Corvo J.,MINES ParisTech | Angulo J.,MINES ParisTech | Breugnot J.,SILAB | Borbes S.,SILAB | Closs B.,SILAB
Progress in Biomedical Optics and Imaging - Proceedings of SPIE | Year: 2016

Principal Component Analysis (PCA) is a technique of multivariate data analysis widely used in various fields like biology, ecology or economy to reduce data dimensionality while retaining most important information. It is becoming a standard practice in multispectral/hyperspectral imaging since those multivariate data generally suffer from a high redundancy level. Nevertheless, by definition, PCA is meant to be applied to a single multispectral/hyperspectral image at a time. When several images have to be treated, running a PCA on each image would generate specific reduced spaces, which is not suitable for comparison between results. Thus, we focus on two PCA based algorithms that could define common reduced spaces of representation. The first method arises from literature and is computed with the barycenter covariance matrix. On the contrary, we designed the second algorithm with the idea of correcting standard PCA using permutations and inversions of eigenvectors. These dimensionality reduction methods are used within the context of a cosmetological study of a foundation make-up. Available data are in-vivo multispectral images of skin acquired on different volunteers in time series. The main purpose of this study is to characterize the make-up degradation especially in terms of texture analysis. Results have to be validate by statistical prediction of time since applying the product. PCA algorithms produce eigenimages that separately enhance skin components (pores, radiance, vessels.). From these eigenimages, we extract morphological texture descriptors and intent a time prediction. Accuracy of common reduced spaces outperform classical PCA one. In this paper, we detail how PCA is extended to the multiple groups case and explain what are the advantages of common reduced spaces when it comes to study several multispectral images. © 2016 SPIE.


A yeast strain expressing a bi-functional fucokinase/GDP-L-fucose pyrophosphorylase enzyme and capable of producing GDP-L-fucose in vivo is provided. Also provided are yeast cells which express a GDP-L-fucose transporter and/or a fucosyl transferase with the bi-functional enzyme. In addition, the said yeast contains one or more expression cassettes for fusion proteins of heterologous glycosylation pathway and an ER/Golgi retention sequence. Finally, the invention also provides a method for producing recombinant target glycoproteins.


PubMed | SILAB and Ecole Normale Superieure de Lyon
Type: | Journal: Scientific reports | Year: 2016

UV irradiation is a major environmental factor causing skin dryness, aging and cancer. UVB in particular triggers cumulative DNA damage, oxidative stress and mitochondrial dysfunction. The objective of our study was to provide both qualitative and quantitative analysis of how mitochondria respond to UVB irradiation in normal human epidermal keratinocytes (NHEK) of healthy donors, with the rationale that monitoring mitochondrial shape will give an indication of cell population fitness and enable the screening of bioactive agents with UVB-protective properties. Our results show that NHEK undergo dose-dependent mitochondrial fragmentation after exposure to UVB. In order to obtain a quantitative measure of this phenomenon, we implemented a novel tool for automated quantification of mitochondrial morphology in live cells based on confocal microscopy and computational calculations of mitochondrial shape descriptors. This method was used to substantiate the effects on mitochondrial morphology of UVB irradiation and of knocking-down the mitochondrial fission-mediating GTPase Dynamin-related protein 1 (DRP1). Our data further indicate that all the major mitochondrial dynamic proteins are expressed in NHEK but that their level changes were stronger after mitochondrial uncoupler treatment than following UVB irradiation or DRP1 knock-down. Our system and procedures might be of interest for the identification of cosmetic or dermatologic UVB-protective agents.

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