Search results for "Optical imaging"
showing 10 items of 75 documents
Motion Artifact Detection in Confocal Laser Endomicroscopy Images
2018
Confocal Laser Endomicroscopy (CLE), an optical imaging technique allowing non-invasive examination of the mucosa on a (sub)- cellular level, has proven to be a valuable diagnostic tool in gastroenterology and shows promising results in various anatomical regions including the oral cavity. Recently, the feasibility of automatic carcinoma detection for CLE images of sufficient quality was shown. However, in real world data sets a high amount of CLE images is corrupted by artifacts. Amongst the most prevalent artifact types are motion-induced image deteriorations. In the scope of this work, algorithmic approaches for the automatic detection of motion artifact-tainted image regions were develo…
Storage of information in lithium niobate single crystals
2011
Reported studies of recording information were made with a number of LiNbO 3 compositions: stoichiometric and congruent single crystals. The present study shows that recording is possible in pure LiNbO 3 single crystals and in single crystals containing inactive cation dopants. Recording in stoichiometric crystals is likely possible because of a considerable amount of electrons localised in shallow traps. Absence of recorded information in pure congruent crystals were observed.
Imaging to study solid tumour origin and progression: lessons from research and clinical oncology
2017
Biomedical imaging in recent decades has clarified our understanding of normal and pathological cellular processes in vivo. In particular, this approach recently provided insights into processes occurring at a molecular or genetic level rather than at the anatomical level. The evolution of this discipline by engineering have led to its integration into biomedical research to (1) increase sensitivity and resolution imaging and to (2) improve tissue and cell specificity. Currently, imaging approaches are used in three different biomedical areas: (a) identification of cellular processes in physiological and disease state; (b) in vivo single-cell imaging; and (c) identification of new prognosti…
Agreement among 3 optical imaging methods for the assessment of optic disc topography.
2005
Purpose To assess the agreement of disc topography measurements between the Heidelberg Retina Tomograph (HRT II), Retinal Thickness Analyzer (RTA), and Optical Coherence Tomograph (StratusOCT). Design Observational cross-sectional study. Participants Forty-two randomly chosen eyes of 42 subjects. Methods Each subject underwent HRT II, RTA, and StratusOCT examination. Two experienced examiners drew the contour lines for the HRT II and RTA. Bland and Altman plots were used to evaluate agreement for each topographic parameter among the instruments. The Spearman coefficient of rank correlation was evaluated for each topographic parameter. Main Outcome Measures Agreement in the measurement of op…
Addressing subphthalocyanines and subnaphthalocyanines features relevant to fluorescence imaging
2018
International audience; A series of new synthetic subphthalocyanines bear structural features aimed at allowing either fluorescence activation or a bathochromic shift of the absorption band towards the near-infrared window, relevant to optical imaging. X-ray diffraction studies of four subphthalocyanines are reported. Spectrofluorimetric studies on subnaphthalocyanines and activatable subphthalocyanine pro-fluorophores are reported.
Phase imaging via compressive sensing
2013
This communication develops a novel framework for phase imaging at optical wavelength by merging digital lenless phase-shifting holography with single-pixel optical imaging based on compressive sensing.
Probing ensemble polymorphism and single aggregate structural heterogeneity in insulin amyloid self-assembly.
2020
Ensembles of protein aggregates are characterized by a nano- and micro-scale heterogeneity of the species. This diversity translates into a variety of effects that protein aggregates may have in biological systems, both in connection to neurodegenerative diseases and immunogenic risk of protein drug products. Moreover, this naturally occurring variety offers unique opportunities in the field of protein-based biomaterials. In the above-mentioned fields, the isolation and structural analysis of the different amyloid types within the same ensemble remain a priority, still representing a significant experimental challenge. Here we address such complexity in the case of insulin for its relevance…
Phasor-FLIM analysis of Thioflavin T self-quenching in Concanavalin amyloid fibrils
2020
The formation of amyloid structures has traditionally been related to human neurodegenerative pathologies and, in recent years, the interest in these highly stable nanostructures was extended to biomaterial sciences. A common method to monitor amyloid growth is the analysis of Thioflavin T fluorescence. The use of this highly selective dye, diffused worldwide, allows mechanistic studies of supramolecular assemblies also giving back important insight on the structure of these aggregates. Here we present experimental evidence of self-quenching effect of Thioflavin T in presence of amyloid fibrils. A significant reduction of fluorescence lifetime of this dye which is not related to the propert…
Site-specific near-infrared fluorescent labelling of proteins on cysteine residues with meso -chloro-substituted heptamethine cyanine dyes
2018
International audience; Near-infrared (NIR) fluorescence imaging is a promising new medical imaging modality. Associated with a targeting molecule, NIR fluorophores can accumulate selectively in tissues of interest and become valuable tools for the diagnosis and therapy of various pathologies. To facilitate the design of targeted NIR imaging agents, it is important to identify simple and affordable fluorescent probes, allowing rapid labelling of biovectors such as proteins, ideally in a site-specific manner. Here, we demonstrate that heptamethine cyanine based fluorophores, such as IR-783, that contain a chloro-cyclohexyl moiety within their polymethine chain can react selectively, at neutr…
Site-Specific Dual Labeling of Proteins on Cysteine Residues with Chlorotetrazines
2018
International audience; Dual-labeled biomolecules constitute a new generation of bioconjugates with promising applications in therapy and diagnosis. Unfortunately, the development of these new families of biologics is hampered by the technical difficulties associated with their construction. In particular, the site specificity of the conjugation is critical as the number and position of payloads can have a dramatic impact on the pharmacokinetics of the bioconjugate. Herein, we introduce dichlorotetrazine as a trivalent platform for the selective double modification of proteins on cysteine residues. This strategy is applied to the dual labeling of albumin with a macrocyclic chelator for nucl…