A5000872118- Advanced Electron Microscopy Techniques and Applications
- Electron and X-Ray Spectroscopy Techniques
- Advanced X-ray Imaging Techniques
- Medical Imaging Techniques and Applications
- Medical Image Segmentation Techniques
- RNA and protein synthesis mechanisms
- Image and Signal Denoising Methods
- Medical Imaging and Analysis
- Advanced X-ray and CT Imaging
- Single-cell and spatial transcriptomics
- Melanoma and MAPK Pathways
- Electrical and Bioimpedance Tomography
- Geomagnetism and Paleomagnetism Studies
- Integrated Circuits and Semiconductor Failure Analysis
- Photoacoustic and Ultrasonic Imaging
- Microtubule and mitosis dynamics
- Photosynthetic Processes and Mechanisms
- Molecular Biology Techniques and Applications
- Image Processing Techniques and Applications
- Genomics and Chromatin Dynamics
- Protist diversity and phylogeny
- ATP Synthase and ATPases Research
- Anodic Oxide Films and Nanostructures
- Cell Adhesion Molecules Research
- Salivary Gland Disorders and Functions
Université Paris Sciences et Lettres
2019-2024
Institut Curie
2014-2024
Centre National de la Recherche Scientifique
2004-2024
Université Paris-Saclay
2016-2024
Inserm
2009-2024
ORCID
2021
Institut des Hautes Études Scientifiques
2020
Université Paris-Sud
2016-2019
Centre Hospitalier d'Orsay
2017
Institut d'Imagerie Biomédicale
2006-2014
Tilt series are commonly used in electron tomography as a means of collecting three-dimensional information from two-dimensional projections. A common problem encountered is the projection alignment prior to 3D reconstruction. Current techniques usually employ gold particles or image derived markers correctly align images. When these not present, correlation between adjacent views them. However, sequential pairwise prone bias and resulting always optimal.In this paper we introduce an...
We present here the application of energy-filtered transmission electron microscopy (EFTEM) in tomographic mode to determine precise 3D distribution nitrogen within nitrogen-doped carbon nanotubes (N-CNTs). Several tilt series images were acquired on K ionization edges and a multiwalled N-CNT containing high amount nitrogen. Two 2D maps then calculated from corresponding by using proper extraction procedure chemical signals. Applying iterative reconstruction algorithms provided two spatially...
Image denoising is a very important step in cryo-transmission electron microscopy (cryo-TEM) and the energy filtering TEM images before 3D tomography reconstruction, as it addresses problem of high noise these images, that leads to loss contained information. High levels contribute particular difficulties alignment required for reconstruction. This paper investigates are acquired with low exposure time, primary objectives enhancing quality low-exposure time improving process. We propose...
Objectives The RNA epitranscriptomic modification known as N6 -methyladenosine (m 6 A) represents a novel mechanism of gene regulation that is poorly understood in human autoimmune diseases. Our research explores the role this m A salivary gland epithelial cells (SGEC) and its impact on pathogenesis Sjögren’s disease (SjD). Methods SGECs from SjD patients controls were analysed for writers METTL3 METTL14 expression using RNA-seq, quantitative PCR immunohistochemistry. Functional assays...
Abstract ASC-G4 is an algorithm for the calculation of advanced structural characteristics G-quadruplexes (G4). It allows unambiguous determination intramolecular G4 topology, based on oriented strand numbering. also resolves ambiguity in guanine glycosidic configuration. With this algorithm, we showed that use C3’ or C5’ atoms to calculate groove width more appropriate than P and does not always reflect space available within groove. For latter, minimum appropriate. The application 207...
Abstract Centrioles are components of the centrosome, which is present in most eukaryotic cells (from protozoa to mammals). They organize microtubule skeleton during interphase and mitotic spindle cell division. In ciliate cells, centrioles form basal bodies that involved cellular motility. Despite their important roles biology, detailed structure remains obscure. This work contributes a more complete model centriole structure. The authors used electron tomography isolated centrosomes from...
A central challenge in scanning transmission electron microscopy (STEM) is to reduce the radiation dosage required for accurate imaging of 3D biological nano-structures. Methods that permit tomographic reconstruction from a reduced number STEM acquisitions without introducing significant degradation final volume are thus particular importance. In random-beam (RB-STEM), projection measurements acquired by randomly subset pixels at every tilt view. this work, we present tailored RB-STEM...
Detection of fluorescent probes by fluorescence in situ hybridization cells with preserved three-dimensional nuclear structures (3D-FISH) is useful for studying the organization chromatin and localization genes interphase nuclei. Fast reliable measurements relative positioning spots specific to subchromosomal regions would improve understanding cell structure function.3D-FISH protocol, confocal microscopy, digital image analysis were used.New software (Smart 3D-FISH) has been developed...
Abstract Electron tomography is becoming one of the most used methods for structural analysis at nanometric scale in biological and materials sciences. Combined with chemical mapping, it provides qualitative semiquantitative information on distribution elements a given sample. Due to current difficulties obtaining three-dimensional (3D) maps by energy-filtered transmission electron microscopy (EFTEM), use 3D mapping has not been widely adopted community. The lack specialized software further...
A new multi-platform freeware has been developed for the processing and reconstruction of scanning multi-technique X-ray imaging tomography datasets. The software platform aims to treat different techniques: fluorescence, phase, absorption dark field any their combinations, thus providing an easy-to-use data tool user community. dedicated input stream copes with management large datasets (several hundred GB) collected during a typical fast scan at Nanoscopium beamline even on standard PC. To...
Abstract The MITF transcription factor and the RAS/RAF/MEK/ERK pathway are two interconnected main players in melanoma. Understanding how activity is regulated represents a key question since its dynamic modulation involved phenotypic plasticity of melanoma cells their resistance to therapy. By investigating role ARAF NRAS-driven mouse through mass spectrometry experiments followed by functional siRNA-based screen, we unexpectedly identified as direct partner. Interestingly, this interaction...
Tools for taking advantage of phase-contrast in transmission electron microscopy are great interest both biological and material sciences studies as shown by the recent use phase plates development holography. Nevertheless, these tools most often require highly qualified experts access to advanced equipment that can only be considered after preliminary investigations. Here we propose address this issue an ImageJ plugin allow retrieval a image simple numerical treatment applied two defocused...
Transmission electron tomography is becoming a powerful tool for studying subcellular components of cells. Classical approaches consist recording images along single-tilt axis. This approach being improved by dual-axis reconstructions and/or high-tilt devices (tilt angle>+/-60 degrees) on microscopes to compensate part the information loss due 'missing wedge' phenomena.In present work we have evaluated extension technique multiple-axis approach, and demonstrate freely available plug-in...
Abstract The characterization of biological and inorganic materials by determining their three-dimensional structure in conditions closer to native state is a major challenge technological research. Environmental scanning electron microscopy (ESEM) provides access the observation hydrated samples water environments. Here, we present specific device for ESEM transmission mode, allowing acquisition tilt-series suitable tomographic reconstructions. resolution which can be obtained with this...
Electron tomography is a technique to obtain three-dimensional structural information of samples. However, the limited by shifts occurring during acquisition that need be corrected before reconstruction process. In 2009, we proposed an approach for post-acquisition alignment tilt series images. This was marker-free, based on patch tracking and integrated in free software. Here, present improvements method make it more reliable, stable accurate. addition, modified image formation model...
<h3>Background:</h3> Sjögren's disease (SjD) is an autoimmune condition marked by lymphocytic infiltration of exocrine glands, where salivary gland epithelial cells (SGECs) play a crucial role in initiating and amplifying inflammation. To address dysfunction, understanding the mechanisms behind pro-inflammatory signaling SGECs vital. Epitranscriptomics, recent field, highlights RNA modifications' impact on gene expression regulation. Writers such as METTL3/14 add methyl groups to RNA, while...
Using human chromosome painting probes, we looked for homologies between and mountain zebra (<i>Equus hartmannae</i>, Equidae, Perissodactyla) karyotypes. Except two very short segments, all euchromatic regions were found to have a homologous segment. Conserved syntenies previously described in various mammalian orders detected. Each synteny corresponded chromosomal region parts of chromosomes: HSA3 HSA21, HSA7 HSA16, HSA12 HSA22, HSA16 HSA19. Chromosomal segments part HSA11...
Here, we present a protocol for multivariate quantitative-image-based cytometry (QIBC) analysis by fluorescence microscopy of asynchronous adherent cells. We describe steps the preparation, treatment, and fixation cells, sample staining, imaging QIBC. then detail image with our open source Fiji script developed QIBC multiparametric data visualization. Our integrates modern artificial-intelligence-based tools, applying deep learning, robust automated nuclei segmentation minimal user...
Resolution (global and local) is one of the most reported metrics quality measurement in Single Particle Analysis (SPA). However, electron tomography, situation different its computation not straightforward. Typically, resolution estimation global and, therefore, reduces assessment a whole tomogram to single number. it known that spatially variant. Still, up our knowledge, method estimate local tomography lacking. This work introduces MonoTomo, developed locally highest reliable frequency...
Abstract Recent advances in electron microscopy and image analysis techniques have resulted the development of tomography, which makes possible study structures neither accessible to X—ray crystallography nor nuclear magnetic resonance. However, use tomography biological structures, ranging from 100 500 nm, requires developments sample preparation analysis. Indeed, cryo‐electron present two major drawbacks: low contrast recorded images radiation damage. In work we tested, on T4 bacteriophage...